Diastolic Dysfunction Research Articles

Right ventricular myocardial work in heart failure with preserved ejection fraction: insights from invasive cardiopulmonary exercise testing

Abstract Backgrounds Symptoms of heart failure with preserved ejection fraction (HFpEF) is closely related to elevated pulmonary capillary wedge pressure (PCWP) during exercise. The understanding of right ventricle myocardial work, assessing of right ventricular (RV) function utilizing RV pressure–strain loops, in HFpEF is lacking. Methods The study population underwent invasive cardiopulmonary exercise tests, measuring pressures at rest and during exercise to identify HFpEF. Echocardiography assessed LV and RV parameters. Right ventricular myocardial work was calculated using strain-rate and pressure curves, matching them with ECG data. RV global constructive work (RVGCW), RV global work index (RVGWI), RV global wasted work (RVGWW), and RV global work efficiency (RVGWE) were analysed and compared with invasively measured PCWP at resting and peak exercise. Results Between November 2017 and July 2023, 41 patients with adequate data were enrolled, and 21 were diagnosed with HFpEF. There were no significant differences in various echocardiographic parameters between HFpEF and non-HFpEF groups, except higher post-exercise PCWP and mean pulmonary artery pressure. HFpEF patients had higher RVGWW and lower RVGWE. RVGWW and RVGWE had higher predictive ability for HFpEF diagnosis compared to other echocardiographic parameters. While RVGCW (r = 0.0.504, P = 0.001 and r = 0.430, P = 0.006, respectively) and RVGWW correlated (r = 0.408, P = 0.008 and r = 0.621, P <0.001, respectively) with post-exercise ∆PCWP and exercise PCWP, only RVGWW (β=1.981, P=0.044 and β=4.323, p<0.001) being independently associated with both after adjustment for confounding factors. Conclusions RVGWW is a novel parameter that provides an integrative analysis of RV systolic function and correlates more closely with post-exercise ∆PCWP than other standard echocardiographic parameters in HFpEF.

NCOR1 orchestrates macrophage inflammation in heart failure with preserved ejection fraction: a translational study

Abstract Background/Introduction Inflammatory response is a key player in heart failure with preserved ejection fraction (HFpEF) but the underlying mechanisms are poorly understood. Recent studies have shown a critical involvement of cardiac macrophage activation in myocardial remodeling thus contributing to HFpEF. Purpose To investigate the role of cardiac macrophage inflammation in experimental and human HFpEF. Methods We employed a translational approach combining human and murine LV myocardial tissue, FACS analysis of cardiac immune cells, in vitro experiments in RAW 264.7 cells exposed to metabolic stress by palmitic acid (PA), bone marrow-derived macrophages from healthy and HFpEF mice, cardiomyocytes (H9c2), endothelial cells (HAECs) as well as ex vivo functional analyses in LV tissues. Human LV myocardial samples were used to evaluate the pro-inflammatory activity of macrophages in the HFpEF myocardium. Induction of HFpEF in mice was done through a validated mouse model combining metabolic (high-fat diet) and hemodynamic stress (L-NAME). Cardiac function was investigated by high resolution ultrasound imaging (Vevo3100) and the LV myocardial samples were used to study the macrophage polarization and their inflammatory activity. Based on interrogation of available RNA-seq datasets – showing the transcriptional repressor NCOR1 as a relevant signature in macrophages during cardiac inflammation, we generated myeloid cell-specific NCOR1 knockout (Ncor1-KO) transgenic mice to investigate the in vivo effects of NCOR1 deletion on the HFpEF phenotype. Results The expression of macrophage markers in human LV specimens showed an increase in pro-inflammatory macrophages (M1) and a decrease in regulatory macrophages (M2) as compared to age-matched control mice. HFpEF mice showed increased expression of vascular adhesion molecules (ICAM1, ICAM2, E-selectin) and a significant recruitment of M1 macrophages as proved by qPCR, WB, and flow cytometry analysis. Of interest, diastolic dysfunction - assessed by E/A ratio and isovolumic relaxation time (IVRT) – and lung congestion were significantly reduced in mice with macrophage NCOR1 deletion as compared to WT littermates, while exercise tolerance was significantly improved. These findings were associated with a reduction of myocardial inflammation (TNF-a, IL6, IL-1b) in Ncor1-KO mice. In vitro assays showed that stimulation of macrophages with PA induced M1 type switch and increased NCOR1, TNF-a, IL-6, and IL-1b levels, whereas NCOR1 depletion prevented detrimental changes of macrophage secretome (Fig.2). Conclusion NCOR1 is a crucial regulator of immune response and macrophage inflammation in the heart. Our findings highlight its potential as a target for therapies aimed at preventing myocardial damage in HFpEF.

Titin hyper-phosphorylation in the peripheral skeletal muscle but not the diaphragm of HFpEF: association with muscle atrophy and dysfunction

Abstract Background Titin hypo-phosphorylation is an important regulatory mechanism for myocardial stiffness in heart failure with preserved ejection fraction (HFpEF). In contrast, a hyper-phosphorylation of titin in the peripheral skeletal muscle (SKM) was reported in mouse models exhibiting muscle atrophy. In former studies it, was shown that SKM atrophy occurs in HFpEF and is associated with muscle dysfunction and a fiber type shift from type I, towards type II fibers. However, these alterations were not seen in the diaphragm muscle (Dia) and a fiber type shift towards type I was documented. So far, no information about the phosphorylation status of titin is available for SKM and the Dia and its association with muscle dysfunction in HFpEF. Purpose To assess titin phosphorylation in SKM and Dia of a HFpEF animal model and to relate it to muscle function and atrophy. Methods To confirm the development of HFpEF echocardiography was performed in female ZSF1-lean (con, n=18) and ZSF1-obese rats (HFpEF, n=18) at the age of 32 weeks. Skeletal muscle function (soleus) was measured in an organ bath setting after the animals were sacrificed. Tissue of the tibialis anterior muscle (TA) and the diaphragm (Dia) was collected and fixed in formalin or snap frozen in liquid nitrogen. To detect titin expression homogenized TA and Dia tissue samples were resolved on a vertical agarose gel. Phosphorylated titin was detected by staining the gel with Pro-Q Diamond, whereas total titin was visualized using Sypro Ruby. Cross sectional area (CSA) of TA and Dia was quantified after Hematoxylin/eosin staining of tissue section. Myosin heavy chain (MHC) ubiquitination was assessed by western blot. Results Assessment of SKM function revealed significantly reduced maximal absolute (-12 %) and maximal specific force (-22 %) in HFpEF animals when compared to controls. In the TA a significantly reduced CSA was evident in HFpEF (1911±103 vs. 1394±103 µm2, p=0.002), whereas in the diaphragm an increased CSA was noted (438±11 vs. 560±18 µm2, p<0.001). In TA of HFpEF animals, the proportion of phosphorylated titin was significantly elevated whereas the total amount of titin was reduced (Fig. 1A, C). In addition, a significantly higher proportion of ubiquitinated MHC was detected (Figure 1E). However in the Dia these alterations were not observed, even a higher amount of total titin was seen (Fig. 1B, D, F). Furthermore, a significant negative correlation between phosphorylated titin and absolute force (r=-0.461, p=0.035, Fig. 2A) as well as specific force (r=-0.693, p=0.0005, Fig. 2B) was evident. Conclusion In contrast to the heart, the TA showed a titin hyper-phosphorylation in HFpEF, going along with a degradation of total titin. This hyper-phosphorylation could be correlated with a loss of force in the SKM. Additionally a higher ubiquitination of MHC was prevalent in the TA, which may be connected to molecular remodeling and fiber type shift towards a more glycolytic type.

Diagnosing heart failure with preserved ejection fraction in patients with unexplained dyspnoea using left ventricular pressure-volume loops at rest and on exertion

Abstract Background To date, diagnosing heart failure with preserved ejection fraction (HFpEF) remains challenging, especially in euvolaemic patients presenting with unexplained dyspnoea on exertion and reduced exercise capacity. A stepwise approach was introduced with the HFA-PEFF diagnostic algorithm*, in which a relevant number of patients has to undergo invasive workup for a final judgement. Purpose The present study aimed to examine a population of patients with unexplained dyspnoea on exertion, using the diagnostic methods endorsed by the HFA-PEFF algorithm as well as left ventricular (LV) pressure-volume loops at rest, on exertion, and during caval occlusion, in order to identify and describe different phenotypes of HFpEF. Methods We prospectively included patients with unexplained dyspnoea on exertion, a left ventricular ejection fraction (LVEF) of ≥ 50%, and without an obvious cause of the dyspnoea. All patients underwent a comprehensive invasive haemodynamic workup. After invasive rule-out of a haemodynamically relevant coronary artery stenosis, we performed a right heart catheterization at rest (R) and on exertion (E) with an arm ergometer. Real-time continuous pressure-volume loops were obtained using a 7-French conductance catheter at rest, on exertion, and under temporal preload reduction via partial occlusion of the vena cava inferior. Results Thirty patients were included. Two patients had to be excluded from further analysis (one due to a technical failure of the conductance catheter and one with severe hypertension (systolic blood pressure > 200 mmHg) during the assessment). The 28 patients in this analysis had a mean age of 64.4±9.7 years and 57% were female. Eleven patients fulfilled invasively easily obtainable diagnostic criteria of HFpEF (mean pulmonary capillary wedge pressure (mPCWP) at rest ≥ 15 mmHg, exertional mPCWP ≥ 25 mmHg, LV end-diastolic pressure (LVEDP) at rest ≥ 16 mmHg, or exertional LVEDP ≥ 25 mmHg) according to the current guideline*. An additional 15 patients had a normal mPCWP and LVEDP, but fulfilled diagnostic criteria for HFpEF measured by the conductance catheter (time constant of LV relaxation tau > 48 ms and/ or chamber stiffness b > 0.27). We referred to this group as "early HFpEF". Patients with early HFpEF had a significantly higher systolic blood pressure, a worse LV relaxation time, and were more likely to exhibit chronotropic insufficiency compared to the HFpEF group (Table 1). HFpEF patients were characterised by significantly higher natriuretic peptides, LVEDP on exertion, and LV stiffness compared to patients with early HFpEF (pressure-volume loops are depicted in Figure 1). Conclusion Invasive haemodynamic testing for HFpEF in patients with unexplained dyspnoea on exertion via right heart catheterization without obtaining LV pressure-volume loops had a false negative rate of 58%. Better detection, the prognosis, and treatment of this "early HFpEF" population warrants further research.Table 1Figure 1

Prognostic and diagnostic implications of impaired rest and exercise-stress left atrial compliance in heart failure with preserved ejection fraction: Insights from the HFpEF Stress Trial

Abstract Background With emerging therapies, early diagnosis of heart failure with preserved ejection fraction (HFpEF) comes to the fore. Whilst the reference standard of exercise-stress right heart catheterisation is well established, the clinical routine struggles between feasibility of exercise-stress and diagnostic accuracy of available tests. Methods The HFpEF Stress Trial (DZHK-17) prospectively enrolled 75 patients with exertional dyspnoea and echocardiographic signs of diastolic dysfunction (E/e’>8) who underwent simultaneous rest and exercise-stress echocardiography and RHC. HFpEF was defined according to pulmonary capillary wedge pressure (HFpEF: PCWP rest: ≥15mmHg stress: ≥25mmHg). Patients were classified as non-cardiac dyspnoea (NCD) in the absence of HFpEF and cardiovascular disease. LA compliance was defined as reservoir strain (Es)/(E/e’). Follow-up was conducted after 4 years to evaluate cardiovascular hospitalisation (CVH). Results The final study population included 68 patients (HFpEF n=34 and NCD n=34) of which 23 reached the clinical endpoint, 1 Patient was lost to follow-up. Patients with HFpEF according to the HFA-PEFF score (≥5 points) had significantly lower LA compliance at rest (p<0.001) compared to patients with a score ≤4. LA compliance at rest outperformed E/e’ (AUC 0.78 vs 0.87, p=0.024) and showed a statistical trend to outperform Es (AUC 0.79 vs 0.87, p=0.090) for the diagnosis of HFpEF. LA compliance at rest predicted CVH (HR 2.83, 95% CI 1.70-4.74, p<0.001) irrespective of concomitant atrial fibrillation. Conclusions LA compliance at rest can be obtained from clinical routine imaging and bears strong diagnostic and prognostic accuracy. Addition of LA compliance can improve the role of echocardiography as the primary test and gatekeeper.

Novel method in mice to evaluate left atrial (LA) systolic contribution to left ventricular volume (LV) using pressure-volume (PV) loops

Abstract Background LA myopathy is a critically important non-LV contributor to the progression of HFpEF (heart failure with preserved ejection fraction) in patients and is associated with a severe phenotype, leading to impaired cardiac output reserve and reduced exercise capacity. In normal humans LA systole contributes ~20% of total LV filling, but with HFpEF, this contribution decreases to <16% with a greater reliance on this contribution to LV filling. Purpose We sought to investigate LA function as a critical component of cardiac function analysis by utilizing the LV pressure signal to identify and quantify the contribution of volume during LA systole to the total LV volume in mice with HFpEF. Methods Hypertension (HTN)-associated HFpEF C57BL/6J mice were subjected to chronic aldosterone infusion and 1% NaCl for 4 weeks (SAUNA model). Obesity after a high fat diet (HFD: 60% fat diet) for 16 weeks followed by the SAUNA protocol, induced HTN and obesity associated HFpEF. Blood pressure was monitored weekly. Mice were anesthetized with isoflurane, intubated, chest opened to expose the heart and allow placement of a PV catheter (Transonic) which was introduced into the LV via apical stab with a 27G needle. Calibration of the PV catheter was performed according to the manufacturer’s instructions. Atrial systole was identified using 2nd order derivative of the LV pressure signal. Contribution of LA systole was calculated using volume at the beginning of LA systole identified by the 2nd order derivative of the LV pressure signal and subtracting from the LV end diastolic volume. The % of LA systole contribution was calculated as a % of the total LV stroke volume. Data was analyzed with LabChart pro software (AD Instruments). Results SAUNA mice had normal LVEF, moderate HTN and lung congestion. PV relationships demonstrated Tau was impaired in HFpEF vs. control mice (14±1 vs. 10±0.5 ms) with a shift of the PV loop to the left (Fig. A.) In control mice, the atrial systole contributed 39± 4% to LV volume and was impaired in HFpEF mice 20± 3% a 1.95-fold reduction (P<0.01). Importantly atrial systole contribution was increased in obese mice 53±5 %. However, the combination of obesity and HTN, both common comorbidities in HFpEF, resulted in a reduced LA systole contribution by 1.43-fold to 37± 9%, (P<0.005; Fig B). Conclusion A novel method of % atrial systole from LV PV loop using 2nd order derivative to quantify the volume contribution of atrial systole to total LV stroke volume was identified in mice. LA dysfunction was present in murine HTN-associated HFpEF with/without obesity.

Gradual hypertensive response in aortic alterations and myocardial inflammatory activation in progressing HFpEF in mice

Abstract Introduction Hypertension is the most common comorbidity in patients affected by heart failure with preserved ejection fraction (HFpEF). Early effects of pressure overload and its contribution to the gradual development of cardiac and vascular pathology leading to HFpEF are not well recognized, as patients are diagnosed when the disease has already advanced and show symptoms. Several hypertensive HFpEF mouse models possessing the hallmarks of the clinical-like phenotype are available. Nonetheless, initial and gradual pathological manifestations of hypertensive HFpEF have not been comprehensively described. Purpose This study aimed to investigate the gradual progression of HFpEF phenotype development in mice from the early manifestation of cardiac and vascular pathology to global cardiac dysfunction to multiorgan syndrome in response to hypertension. Methods Hypertensive HFpEF was induced by angiotensin II infusion in C57BL/6JOlaHsd 18-20-week-old male mice that were given low, moderate and high doses (0.5mg/kg/day - 1.5 mg/kg/day) subcutaneously for 4 weeks. Cardiac physiology and alterations in haemodynamics were assessed with echocardiography of heart and aorta, weekly ECG monitoring, and blood pressure measurements from the mouse tail. Extensive histology and immunohistochemistry analyses of cardiac tissue, microvasculature, lungs and kidneys were performed. Results In the low dose group, loss of aortic wall flexibility and presence of aortic root dilatation were detected. This group also demonstrated initiation of concentric remodelling process with the upsurge in macrophage infiltration in myocardium, but the signs of diastolic dysfunction were not yet present. The high dose group exhibited characteristic HFpEF features with diastolic dysfunction, left ventricular hypertrophy and fibrosis. Pathology in cardiac conduction system was noticed in all groups, with prominent ECG waveform abnormalities already on week one. However, only the high dose group experienced non-recovery in impulse propagation, accompanied by significant prolongation of ventricular depolarization. Conclusion This study demonstrates that change in aortic root dimensions and aortic wall dynamics are the first hypertension-sensitive alterations together with myocardial inflammatory cell infiltration that may contribute to myocardial remodelling and subsequent development of HFpEF and systemic effects. Hypertensive angiotensin II-induced HFpEF is a relevant mouse model, recapitulating not only hallmarks of cardiac pathology but also an extensive range of vascular and multiorgan alterations, demonstrating similarities with the clinical phenotype.

Clinical characteristics and long-term outcomes of patients with heart failure with supra-normal ejection fraction: data from LECRA-HF registry

Abstract Background Heart failure with preserved ejection fraction (HFpEF) remains insufficiently characterized subgroup of HF with increasing prevalence and limited treatment options. Relationship between clinically assessed left ventricular ejection fraction (LVEF) and survival showed that LVEF ≥65% is associated with higher mortality. Therefore, a novel category of heart failure with supra-normal left ventricular ejection fraction (HFsnEF) was introduced in 2019. However, clinical characteristics and long-term outcomes of HFsnEF patients remain insufficiently elucidated. Purpose We sought to characterize Polish HFsnEF patients and to provide their long-term mortality in comparison to HFpEF. Methods Of 1186 patients enrolled in the single-center Lesser Poland Cracovian Heart Failure (LECRA-HF) Registry between 2009 and 2019 and hospitalized due to HF decompensation 261 (22%) of them were those with LVEF ≥50%. 40 (15.3%) of them were classified as HFsnEF (LVEF ≥65%) and the remaining 221 (84.7%) as HFpEF. The data including patients’ demography, anthropometric measurements, cardiovascular risk factors, prior cardiological treatment and other comorbidities were collected. The long-term follow-up of all-cause mortality was obtained from the Polish National Death Registry. Results HFsnEF patients were less frequently hypertensive (75 vs 88.2%, P=0.026) and had higher baseline LVEF (65 [65-70] vs 55 [50-60] %, P<0.001) than HFpEF subjects. Furthermore, HFsnEF patients presented lower INR (1.1 [1-1.6] vs 1.3 [1.1-1.9], P=0.027) and total protein level (57 [25-63] vs (65.2 [60.2-69.9] g/L, P=0.008) on admission. HFsnEF patients were less frequently treated on discharge with mineralocorticoid receptor antagonists (25 vs 46.2%, P=0.013) as well as loop diuretics (60 vs 76%, P=0.017). The Kaplan-Meier analysis showed that all-cause mortality is higher in HFsnEF than in HFpEF (65.0 vs 55.2%, P=0.044, Figure 1). The independent predictors of long-term mortality were age and diagnosis of HFsnEF (HR 1.037, 95% CI 1.018-1.056 and HR 1.665, 95% CI 1.063-2.608, respectively). Conclusions Our findings indicate that every seventh Polish patient admitted with HFpEF could be classified as HFsnEF. Baseline characteristics of HFsnEF patients are different than HFpEF. Simultaneously, the HFsnEF diagnosis is associated with lower long-term survival.

Pathobiological characterization of pulmonary hypertension associated with heart failure with preserved ejection fraction

Abstract Introduction Heart failure with preserved ejection fraction (HFpEF) is an age-related cardiometabolic disease associated with vascular inflammation in cardiac tissue, pulmonary congestion and right ventricular dysfunction. Patients with HFpEF often develop pulmonary hypertension (PH) and right ventricular (RV) hypertrophy. Pulmonary vascular remodeling contributes to combined post- and precapillary PH (CpcPH), which is associated with worse outcome in humans. A recently developed meta-inflammatory murine HFpEF model approximates the characteristics of human HFpEF. Herein, HFpEF is induced by metabolic (high-fat diet (HFD)) and hypertensive stress (inhibition of constitutive NO synthase by Nω-nitro-1-arginomethyl ester (L-NAME)) over a 12-week period of time. With a focus on PH, we have developed a 'three-hit' model based on this model with a supplementary 21- or 42-day hypoxia phase (HFpEF-CpcPH). Methods Adult C57BL/6N mice were fed HFD for 15 or 18 weeks and supplied with L-NAME (0,5g/L or 1g/L) via drinking water, including a final period of 21 or 42 days, respectively, of hypoxia (normobaric, 10 % oxygen) or normoxia. Transthoracic echocardiography was performed using a small animal ultrasound device (Vevo 3100, Visual Sonics) and measurement of right ventricular systolic pressure (RVSP) using a Millar® pressure catheter (Mil-SPR-1000) inserted into the right ventricle. Right ventricular hypertrophy was measured as the ratio of the wet weight of the right ventricle to the left ventricle including the septum (RV/LV+S). Results Administration of HFD and L-NAME had no significant effect on RVSP in either HFpEF-normoxia group (15 weeks (n=8) or 18 weeks (n=5)) compared to the control group (n=8, n=5). 21 days of hypoxia increased RV systolic pressure (RVSP) to 37.05±1.6 (PH, n=8) and 40.33±0.87 mmHg (HFpEF-CpcPH, n=8) respectively, while 42 days of hypoxia caused no further increase (35.1±3.5 mmHg (PH, n=5) and 35.24±3.47 mmgHg (HFpEF-CpcPH, n=4)), respectively. RV hypertrophy (RV/LV+S) was significantly increased after 21 days of hypoxia in HFpEF-CpcPH compared to HFpEF (n=8) (34.42±1.75 vs. 24.93±1.1). Again, 42 days of hypoxia did not lead to a further increase in RV hypertrophy (35.2±3.9 vs. 25.80±4.39) in HFpEF-CpcPH, even though there was a significant difference compared to the HFpEF group. As expected, the heart weight/body weight ratio was significantly increased in HFpEF-CpcPH compared to HFpEF at both time points. However, mice under the prolonged hypoxia phase showed a significantly greater decrease in body weight, which complicates the interpretation of the results. Conclusion In summary, we could show that in the meta-inflammatory HFpEF model no significant PH can be observed within the investigated periods of time. However, a 21 day hypoxia phase was sufficient to induce a HFpEF-CpcPH phenotype. This model provides an important basis to develop new therapeutic approaches.

Characteristics and outcomes of patients with a history of cancer enrolled in our prospective HFpEF registry

Abstract Background Along with the aging population, the incidence of concomitant heart failure with preserved ejection fraction (HFpEF) and cancer, is increasing. However, little is known about the typical characteristics of patients with both HFpEF and a history of oncologic disease. Aim We aimed to characterize the distinctive characteristics and outcomes of patients with a history of cancer within a prospective HFpEF registry. Methods We analyzed data from 491 unselected HFpEF patients from our tertiary university center between 2010 and 2022 and followed the patients until 2023. Laboratory parameters and comorbidities were assessed. Patients were categorized into those with and without a history of cancer, including various malignancies, survivors of childhood cancer, radiation therapy, with or without chemotherapy. Kaplan-Meier estimates were used to explore the association between cancer history, as well as previous radiotherapy, and a combined endpoint of heart failure hospitalization and/or all-cause death. Results In this analysis of 491 HFpEF patients, a total of 101 patients (21%); had a history of cancer [mean age 74±7 years; female 72 (72%), male 29 (29%)]. The median time from cancer diagnosis to the initial HFpEF visit was 7.0 years (IQR 13-0.5 years). The most prevalent primary cancer sites included the chest wall (32%) comprising 4 adenocarcinomas of the lung and 28 cases of breast cancer, followed by the gastric (28%), urogenital system (18%), hematologic and lymphatic system (16%), cancers located at the head and neck (5%) and endocrine malignancies (1%). Radiotherapy (39%) and chemotherapy (26%) were common. Notably, no significant differences were observed, between patients with or without a history of cancer, in terms of median NT-proBNP levels [1037 (IQR 416-2075) vs. 1060 pg/ml (IQR 462-2013)] and the frequency of key cardiovascular comorbidities (all p>0.05, see Table 1). Over the study period [median follow-up 50 months (IQR 18-76)], 64 (64%) of cancer patients met the combined endpoint, with no statistically significant difference in outcomes between HFpEF patients with and without a cancer history (log-rank p=0.222, see Figure 1). Furthermore, there was no significant difference in the combined endpoint between patients who had undergone radiotherapy and those without (log-rank p=0.162). Conclusion Our findings highlight a high coexistence of cancer and HFpEF, which can frequently occur after oncology therapies. The data suggest that the presence of a history of cancer or previous radiotherapy did not significantly impact overall outcomes in HFpEF patients compared to those without cancer during the study period. Further research is needed to characterize patients with both disease entities in detail. Due to modern cardiovascular therapy in a university and cardio-oncology clinic setting, outcomes for cancer patients appear better than expected.

Improvement of left atrial function after ablation in patients with paroxysmal atrial fibrillation is associated with the presence of heart failure with preserved ejection fraction

Abstract Background Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) often coexist and left atrial (LA) function was impaired in both AF and HFpEF. However, It remains unclear if HFpEF is linked to LA function improvement in paroxysmal atrial fibrillation (pxAF) patients post-ablation. Purpose To investigate whether the improvement of LA function after ablation in patients with pxAF combined with HFpEF is better than that in patients without HFpEF. Methods 147 patients with pxAF were enrolled and HFpEF was ascertained based on the H2FPEF score. All patients underwent transthoracic echocardiography (TTE) at baseline and 3 months after ablation. Left atrial volume index (LAVI), left atrial ejection fraction (LAEF) and left atrial peak reservoir strain (LA RS) were measured. Improvement of left atrial function is defined as the difference in the above 3 indicators at baseline and 3 months after ablation. The change of the above atrial functional parameters was compared between patients with high-probability of HFpEF [hp-HFpEF] and medium/low-probability of HFpEF [lp-HFpEF]) in univariate and multivariate analysis. Statistical analyses were conducted using independent samples t-tests, Mann-Whitney U tests, and ANCOVA. Results 147 patients were included (30 hp-HFpEF, 117 lp-HFpEF, mean age 62.6 years, 63.3% men, mean BMI 25.54kg/㎡, mean disease course 28.2 months, mean CHA2DS2-VASc score 1.97). In the univariate analysis, the following factors were significantly different between hp-HFpEF and lp-HFpEF, including BMI (26.95±3.71 vs. 25.18±3.00, p=0.007), CHA2DS2-VASc score (3[3-4] vs. 2[1-2], p＜0.001), LA function at baseline including LAVI (41.59±11.38 vs. 32.57[27.68-41.10], p=0.003), LAEF (45.97±10.26 vs. 57.23±9.08, p＜0.001), LA RS (26.43±10.68 vs. 34.43±10.60, p＜0.001), and difference at baseline and 3 months after ablation in LA function including LAVI (4.92±1.08 vs. 3.33±1.18, p＜0.001), LAEF (13.41±9.71 vs. 2.98±9.69, p＜0.001), LA RS (23.61±10.23 vs. 7.29±6.91, p＜0.001), and in left ventricular (LV) TTE indicators including E/e’ (3.10±2.30 vs. -0.32±2.68, p＜0.001), LV ejection fraction (10.5[7.0-16.5] vs. 2.0[-5.0-6.0], p＜0.001), LV global longitudinal strain (14.94±4.27 vs. 5.15[2.63-8.30], p＜0.001) and LV mass (17.79±28.67 vs 1.50[-8.75-17.00], p=0.006). After adjusted for BMI, CHA2DS2-VASc score, LA function at baseline and difference at baseline and 3 months after ablation in LV TTE indicators, the improvement of LA function 3 months after ablation in patients with hp-HFpEF is better than that in patients with lp-HFpEF: LAVI significantly decreased (4.24±0.21 vs. 3.46± 0.09, p＜0.001), LAEF significantly increased (12.90±2.13 vs. 3.09±0.86, p＜0.001) and LA RS significantly increased (21.44±1.81 vs. 8.02±0.76, p＜0.001) in hp-HFpEF compared with lp-HFpEF. Conclusion Patients with pxAF with hp-HFpEF showed better improvement in LA function after ablation than those with Ip-HFpEF.

Effect and mechanism of Adipokine Omentin-1 on cardiac hypertrophy in heart failure with preserved ejection fraction

Abstract Background Omentin-1 secreted by epicardial adipose tissue can inhibit ventricular remodeling and improve early cardiac function after myocardial infarction. Our previous studies have identified the omentin-1 receptor as integrin receptors αvβ3 and αvβ5. However, the effect of omentin-1 on heart failure with preserved ejection fraction (HFpEF) remains poorly understood. Purpose The present study aims to study the role and mechanism of omentin-1 in cardiac function and myocardial cell structure in HFpEF. Methods and Results The influences of omentin-1 were investigated in HFpEF mice (HFD (60% calories from lard) and L-NAME (0.5 g/L in drinking water)), which were treated in vivo. Echocardiography showed better diastolic function in HFpEF mice treated with omentin-1 (5 ug/kg/h) subcutaneously for 4 weeks, and tissue staining showed alleviated myocardial fibrosis and myocardial hypertrophy. The RNA sequencing analysis revealed variations in the gene expression related to ketone body metabolism in HFpEF mice after omentin-1 treatment (600 ng/ml). The supernatant was obtained from mouse bone marrow macrophages treated with ultrapure endotoxin and ATP and was utilized as the macrophage-conditioned medium for culturing primary cardiomyocytes, which were stimulated with isoproterenol for 48 hours to construct the HFpEF cardiomyocyte model. In the heart tissue of HFpEF mice and HFpEF cardiomyocytes treated with omentin-1, there was a notable increase in the expression of a pivotal enzyme of ketone body metabolism- succinyl-CoA transferase (SCOT), and a decrease in the expression of hypertrophy signal. The myocardial hypertrophy model was established by stimulating the myocardial cell line H9C2 with isoproterenol. Following the inhibition of the integrin receptor and PI3K-AKT pathway, the impacts of omentin-1 on SCOT and myocardial hypertrophy signal expression in hypertrophic cardiomyocytes were eliminated. Conclusion This study provides evidence for the effects of omentin-1 on cardiac function and myocardial structure in HFpEF and proposes that omentin-1 may stimulate the downstream PI3K/AKT pathway via integrin receptors on cardiomyocytes, leading to increased expression of SCOT and improvement of cardiomyocyte hypertrophy.

Exosome-like nanovesicle targeting visceral adipose tissue inflammation mitigates heart failure with preserved ejection fraction

Abstract Introduction Heart failure (HF) with preserved ejection fraction (HFpEF) is associated with chronic systemic inflammation and obesity, with limited therapies. Inflammation in visceral adipose tissue (VAT) was significantly evoked in obese mice; while mesenchymal stem cell (MSC), especially atorvastatin (ATV)-pretreated MSC, could promote anti-inflammatory phenotype switch of immunocytes (e.g. macrophages), serving as a promising therapy for obesity-related HFpEF. Thus, the study was designed to prepare a novel ATV-pretreated MSC-derived exosome-like nanovesicles (ELNVs) and assess the anti-inflammatory and cardioprotective effects of ELNVs. Methods ELNVs derived from unpretreated MSC (ELNVM) or ATV-pretreated MSC (ELNVMA) were prepared and characterized (Figure 1). PKH-26-labelled ELNVs were incubated with THP1 cells for cell uptake assay. For anti-inflammatory studies in vitro, ELNVs (5×1010/mL) were added into the medium, followed by the induction of M1 or M2 polarization. The expressions of iNOS and Arg1 were measured by immunofluorescence (IF) staining. A 2-hit preclinical mice model of HFpEF, established by a 12-week high-fat diet (HFD) and Nω-Nitro-L-arginine methyl ester hydrochloride administration (0.5 g/L), was applied and received normal saline (NS) or ELNVs (i.p., 5×1011/kg body weight, 3 times a week). Functional and histological analysis including echocardiography, exhaustion test, WGA staining for hearts and western blot for VAT were performed. Quantitative polymerase chain reaction (qPCR) of key long non-coding RNAs (lncRNAs) was used to identify the mediator in ELNVs. Results The mean diameters of ELNVM and ELNVMA were 109.5 and 114.6 nm respectively and both ELNV types could be taken by THP1 cells. VAT inflammation was activated in HFpEF mice compared to the control in terms of the protein levels of iNOS and Arg1. An elevated expression of Arg1 and a decreased level of iNOS was observed in THP1 cells in vitro and VAT in vivo in both ELNV groups (P<0.05, Figure 1 and 2). Consistently, levels of interleukin (IL)-1β were increased in VAT of HFpEF mice, which were downregulated in ELNVM and ELNVMA groups. Both ELNVs could reduce the E/E’, and attenuate cardiac hypertrophy (heart weight to tibial length) and pulmonary congestion (lung weight [wet to dry]) (all P<0.05), with more pronounced improvements in ELNVMA group (Figure 2). Results of qPCR indicated three lncRNA candidates (TARID, H19 and KLF3-AS1) that were previously reported to inhibit M1 polarization or promote M2 polarization, were elevated in ELNVMA compared to ELNVM (P<0.05). Conclusion VAT inflammation was evoked in HFpEF mice and contributed to the development of HFpEF. This pilot study developed a novel ATV-pretreated ELNVs, which might serve as a promising tool for alleviating HFpEF due to the charming anti-inflammatory and cardioprotective effects mediated by regulating VAT macrophages.Figure 1.ELNVs’ PreparationFigure 2.Anti-inflammation of ELNVs

Alarin regulates RyR2 and SERCA2 to improve cardiac function in heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction (HFpEF), a complex disease that is increasingly prevalent due to population aging, pose significant challenges in its treatment. The present study utilized the HFpEF rat model and H9C2 cells as research subjects to thoroughly investigate the potential mechanisms of alarin in protecting cardiac function in HFpEF. The study shows that under HFpEF conditions, oxidative stress significantly increases, leading to myocardial structural damage and dysfunction of calcium ion channels, which ultimately impairs diastolic function. Alarin, through its interaction with NADPH oxidase 1 (NOX1), effectively alleviates oxidative stress and modulates the activities of type 2 ryanodine receptor (RyR2) and sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2), thereby facilitating the restoration of Ca2+ homeostasis and significantly improving cardiac function in the HFpEF model. This research not only uncovers the cardioprotective effects of alarin and its underlying molecular mechanisms but also provides new insights and potential therapeutic targets for HFpEF treatment strategies, suggesting a promising future for alarin and related therapies in the management of this debilitating condition.

Dapagliflozin enhances arterial and venous compliance during exercise in heart failure with preserved ejection fraction

Abstract Background Systemic arterial compliance and venous capacitance are typically impaired in patients with heart failure with preserved ejection fraction (HFpEF), contributing to hemodynamic congestion with stress. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) reduce hemodynamic congestion and improve clinical outcomes in patients with HFpEF, but the mechanisms remain unclear. Purpose This study tested the hypothesis that SGLT2i dapagliflozin would improve systemic arterial compliance and venous capacitance during exercise in patients with HFpEF. Methods In this secondary analysis from the RCT trial, patients with HFpEF underwent invasive hemodynamic exercise testing at baseline and following treatment for 24 weeks with dapagliflozin or placebo. Patients were required to display pulmonary capillary wedge pressure (PCWP) ≥25 mmHg during exercise at the time of baseline evaluation. Radial artery pressure (BP) was measured continuously using a fluid-filled catheter with transformation to aortic pressure, central hemodynamics were measured using high-fidelity micromanometers, and stressed blood volume was estimated (eSBV) from hemodynamic indices fit to a comprehensive cardiovascular model. Results A total of 37 patients completed the study and were included in this analysis (21 dapagliflozin and 16 placebo). Patients were predominantly women (24/37, 65%) and older (mean age 67 years). There was no statistically significant effect of dapagliflozin on resting BP, but dapagliflozin reduced systolic BP during peak exercise (estimated treatment difference [ETD], -18.8 mmHg, 95% CI: -33.9 to -3.7, P=0.016) (Figure 1A). Dapagliflozin improved exertional total arterial compliance (TAC) index (ETD, 0.06 mL/mmHg/m2, 95% CI: 0.003 to 0.11, P=0.039) (Figure 1B) and aortic root characteristic impedance (ETD, -2.6 mmHg/ml*sec, 95% CI: -5.1 to -0.03, P=0.048) during peak exercise, with no significant effect on systemic vascular resistance. Dapagliflozin reduced eSBV at rest and during peak exercise (ETD, -292 mmHg, 95% CI: -530 to -53, P=0.018) (Figure 1C), and improved venous capacitance evidenced by a decline in ratio of eSBV to total blood volume (ETD, -7.3%, 95% CI -13.3 to -1.3, P=0.020). Each of these effects of dapagliflozin during peak exercise were also observed during matched 20W exercise intensity. Improvements in TAC index and eSBV were correlated with decreases in body weight, and reduction in systolic BP with treatment was correlated with the change in eSBV during exercise (r=0.40, P=0.019) (Figure 2A). Decreases in BP were correlated with reduction in PCWP during exercise (r=0.56, P<0.001) (Figure 2B). Conclusion In patients with HFpEF, treatment with dapagliflozin improved systemic arterial compliance and venous capacitance during exercise, while reducing aortic characteristic impedance, suggesting a reduction in arterial wall stiffness. These vascular effects may partially explain the clinical benefits with SGLT2i in HFpEF.

Enhanced diagnostic accuracy of cardiovascular magnetic resonance in identifying heart failure with preserved ejection fraction through assessment of right ventricular systolic dysfunction

Abstract Backgrounds Right ventricular maladaptive response to increased afterload affects exercise performance in heart failure with preserved ejection fraction (HFpEF). We investigated its role in the diagnosis of early stage of HFpEF with cardiac magnetic resonance (CMR) and invasive cardiopulmonary exercise testing (iCPET). Methods One hundred forty-five patients with suspected HFpEF were prospectively recruited from two centers and 113 of them completely underwent echocardiography, iCPET, and CMR. The diagnosis of HFpEF was based on the result of iCPET (pulmonary capillary wedge pressure > 15mmHg at resting and >25mmHg at peak exercise). Area under the curve (AUC) was determined by comparing HFpEF with non-HFpEF patients. Results Seventy-two HFpEF (68±10 years) and forty-one non-HFpEF (66±11 years) were identified. The resting pulmonary artery compliance was significantly reduced in HFpEF. CMR right ventricle longitudinal strain and left atrial reservoir strain had the highest diagnostic accuracy (AUCs 0.805 and 0.776, respectively). There is a sex disparity in the diagnosis accuracy of left atrial (LA) reservoir strain, with male patients exhibiting a significantly increased AUC (0.801) compared to females (AUC 0.559). Conclusions Right ventricular systolic dysfunction is an early indicator of HFpEF, accompanied by impaired LA filling. The diminished LA filling may be more prevalent in male patients, suggesting distinct early pathophysiological progressions between genders.

Role of the alarmin S100A9 in the pathogenesis of heart failure with preserved ejection fraction

Abstract Background A systemic low-grade inflammation induced by comorbidities is recognized to underlie heart failure (HF) with preserved ejection fraction (HFpEF)-specific remodelling. Recent evidence states that the innate immunity member S100A9, which is mainly present as the heterodimer S100A8/9, is an important contributor of sterile inflammation in the comorbidities of HFpEF, with adipose tissue being an important source. Though, its specific involvement in HFpEF has not been explored so far. Purpose The present study aimed to unravel the role of S100A9 in the pathogenesis of HFpEF via the two-hit HFpEF mouse model, S100A8/9 stimulation on murine left ventricle (LV) and C4 fibroblasts (Fb) and gene expression analysis of endomyocardial biopsy (EMB)-derived Fb from HFpEF and HF with reduced ejection fraction (HFrEF) patients. Methods Wild type (WT) C57BL/6JN or S100A9 knock-out (ko) mice were exposed to a high-fat diet (HFD) and L-NAME (1 g/L in drinking water) over 15 weeks. Controls received standard diet. LV function was characterized via conductance catheter measurements. At the day of sacrifice, the LV, spleen, blood, and adipose tissue were collected for subsequent analyses. In vitro, murine LV-derived Fb and C4 Fb were stimulated with the heterodimer S100A8/9. EMB-Fb from HFpEF and HFrEF patients were screened for S100A9 and downstream components of the NLRP3 inflammasome. Results WT HFD+L-NAME mice exhibited a preserved EF, combined with a reduced LV relaxation (dP/dtmin; p<0.01), elevated LV relaxation time (Tau; p<0.05), and impaired LV contractility (dP/dtmax; p<0.05), in parallel to a low-grade systemic inflammation evident by increased C-reactive protein levels. S100A9+, CD68+ and Ly6G+ cells, and CD68+ and Ly6G+ cells expressing S100A9 were increased in the LV, spleen and adipose tissue of WT HFD+L-NAME mice compared to WT mice on chow diet. Changes in LV function were less pronounced in S100A9ko HFD+L-NAME mice, which were characterized by lower systemic C-reactive protein levels, and lower presence of CD68+ and Ly6G+ cells in the LV, spleen and adipose tissue versus WT HFD+L-NAME mice, in the absence of S100A9. Moreover, S100A9ko HFD+L-NAME exhibited lower expression of pro-inflammatory and fibrosis-related genes versus WT HFD+L-NAME mice. Stimulation of murine LV-Fb and C4 Fb with S100A8/A9 increased the mRNA expression of the pro-inflammatory chemokines chemokine (C-C motif) ligand (CCL) 2 and CCL7, and the % of NLRP3-, ASC-, caspase 1-, and IL-1ß-expressing cells, respectively. Finally, mRNA expression of S100A9 and components of the NLRP3 inflammasome was higher in EMB-Fb of HFpEF versus HFrEF patients. Conclusion These data support that adipose tissue is an extra-cardiac source of S100A9 contributing to systemic low-grade inflammation. S100A8/9 in the heart can boost the inflammatory potential of cardiac fibroblasts, further supporting the pro-inflammatory role of S100A9 in the pathogenesis of HFpEF development.

Real-world evidence for patient phenotypes in heart failure with preserved ejection fraction

Abstract Background Heart failure (HF) with preserved ejection fraction (HFpEF) presents a high mortality risk due to its heterogeneous and multifactorial nature, coupled with limited treatment options. The incompletely understood pathophysiology is influenced by various comorbidities, resulting in different clinical phenotypes. Identifying these could be crucial for tailored HFpEF treatments. While previous studies focused on small, well-characterized patient populations, electronic health records (EHRs) offer the potential to unveil HFpEF phenotypes in larger real-world patient groups. Purpose We aimed to establish a sizable, unselected HFpEF patient population using real-world data. Employing cluster analysis, we intended to uncover distinct groups with varied disease aetiology and medical needs based on comorbidity profiles and prognoses. Methods From EHRs of n = 1,610,101 HF patients, we identified an HFpEF cohort of n = 32,009 patients, by applying thresholds for the LVEF and data availability, and by excluding confounding conditions. Clustering by the relative frequency of common comorbidities aimed to reveal patient populations with unique prognoses, comorbidity profiles, and clinical and demographic characteristics. Results Six clusters of different sizes, comorbidity prevalence, clinical presentation, and all-cause mortality were identified. About 50% of patients (n = 15,445) were predominantly hypertensive, with varying extents of coronary heart disease and diabetes mellitus (DM), and a 5-year mortality of about 30%. Around 22% (n = 7,089) exhibited a cardiometabolic comorbidity profile, with an increased prevalence of obesity and sleep apnea, but also DM and hypertension, and a 5-year mortality of 22.5%. Over 15% of patients (n = 5,298) had a 5-year mortality rate of 45.0%, marked by highest rates of anaemia and chronic kidney disease (CKD) but also DM, elevated N-terminal prohormone of brain natriuretic peptide levels, and a reduced estimated glomerular filtration rate. Conclusion Despite the favourable prognosis, a significant proportion of patients represent a cardiometabolic HFpEF phenotype with notable unmet medical needs regarding cohort size and multimorbidity. Patients simultaneously suffering from CKD, anaemia, and the highest mortality rates may represent a previously underrecognized phenotype. Our study demonstrates that distinct medical needs can be identified in a large, unselected real-world HFpEF cohort. In contrast to clinical trials, this approach enabled access to a broader patient population, revealing novel phenotypes to be targeted by precision medicine in the future.

Comorbidities, pharmacologic interventions, and mechanical interventions associated with mortality in isolated diastolic left heart failure: lessons from a national database.

Diastolic heart failure may be noted in paediatric patients with CHD, cardiomyopathy, or malignancies requiring chemotherapy, but the available data are scarce, and often derived from adult trials or based on theoretic or anecdotal evidence. Data between 2016 and 2021 were obtained from Pediatric Health Information System database. Patients <18 years of age with isolated diastolic heart failure admitted to ICU at some point during admission were included. They were divided into patients with and without inpatient mortality. Patients' demographics, comorbidities using ICD-10 codes, and pharmacologic interventions were also recorded. Univariate analysis was done in demographics, comorbidities, pharmacologic interventions, and mechanical interventions between admissions with and without mortality. Multivariable logistic regression was done for inpatient mortality and multivariable linear regression was done for total hospital length of stay in survivors. Isolated diastolic heart failure comprised 0.5% of critically ill paediatric patients. A total of 121 (5%) experienced mortality among the 2,273 admissions in the final analyses. Milrinone and angiotensin converting enzyme inhibitor were found to be associated with decreased mortality. Increasing age and diuretics were associated with decreased total hospital length of stay in survivors. In the cohort studied, isolated diastolic left heart failure has a 5% mortality. Several comorbidities and interventions are associated with increased mortality with milrinone and angiotensin converting enzyme inhibitors being associated with decreased risk of mortality. When only admissions with survival to discharge are considered, older age and diuretics are associated with lower total hospital length of stay.

Performance of an automated echocardiographic artificial intelligence model. to detect subclinical heart failure with preserved ejection fraction (HFpEF) in community-dwelling older adults

Abstract Background Heart failure (HF) with preserved Ejection Fraction (HFpEF) is common among older adults and associated with a high burden of morbidity and mortality. Early identification of subclinical HFpEF, defined by abnormalities in cardiac structure and function without symptoms of HF, can prompt early initiation of evidence-based therapies to prevent HFpEF. However, scalable strategies for the identification of subclinical HFpEF are lacking. Purpose To evaluate the performance of a validated, automated echocardiographic artificial Intelligence algorithm (Ultromics, UK) to identify subclinical HFpEF among community-dwelling individuals without HF. Methods The study included participants of the Dallas Hearts and Minds Study without HF who underwent cardiovascular phenotyping with resting and exercise echocardiography and maximal cardiopulmonary exercise testing. The resting apical 4C echocardiographic images were analyzed by the AI echo algorithm to identify the HFpEF phenotype (AI-HFpEF). Subclinical HFpEF was defined by E/e’ &amp;gt;14 and Peak exercise oxygen uptake (VO2peak) &amp;lt;25th percentile for the cohort. The performance of the AI algorithm to detect subclinical HFpEF was determined using the area under the receiver operating curve and decision curve analysis and was compared with the previously validated H2FpEF score. The association between the AI-HFpEF phenotype and the presence of subclinical HFpEF, VO2peak, exercise E/e’, left ventricular strain, and left atrial strain was assessed using multivariable-adjusted logistic and linear regression models. Results The study included 511 participants (mean age: 61 y, 57% women, mean VO2peak = 16.9 ml/kg/min). Using the AI echo algorithm, subclinical HFpEF was detected in 10% of participants (n=76), and 10% were non-diagnostic. The participants with (vs. without) AI-HFpEF phenotype were older and had a higher burden of CVD risk factors, left ventricular hypertrophy, and left atrial dilation. Subclinical HFpEF, as defined by the gold standard criteria, was present in 5.3% of participants. The AUROC for diagnosis of subclinical HFpEF using the AI-HFpEF algorithm was 0.85 vs. 0.78 by the H2FpEF score (see Figure). In the adjusted analysis, the AI-HFpEF phenotype was significantly associated with greater odds of subclinical HFpEF by exercise and echocardiographic phenotyping criteria, higher E/e’ with exercise, lower VO2 peak, and worse LV and LA strain (see Table). In decision curve analysis, the AI-HFpEF algorithm identified 23 additional cases of subclinical HFpEF per 1000 screened participants compared with the H2FpEF score. Conclusion The AI-HFpEF algorithm can reliably identify community-dwelling individuals with subclinical HFpEF characterized by diastolic dysfunction at rest or exercise and impaired exercise capacity. Future studies are needed to assess the utility of the AI-HFpEF algorithm in screening for subclinical HFpEF in health systems.