Cardiac Resynchronization Therapy Recipients Research Articles

Rhythm and rate control strategies in patients with long-standing persistent atrial fibrillation treated with cardiac resynchronization: the results of the randomized Pilot-CRAfT study

Abstract Background Atrial fibrillation (AF) is common in cardiac resynchronization therapy (CRT) recipients. It is a marker of impaired CRT response mainly mediated by the reduction of effectively captured biventricular paced beats (BiVp). There are no randomized trials comparing strategies to maintain high BiVp percentage. Objective To compare the efficacy of rhythm vs rate control strategies in CRT recipients with long-standing persistent AF. Methods We performed a randomized trial including CRT recipients with persistent AF resulting in low BiVp%. All patients received amiodarone, the rhythm control group received external electrical cardioversion (EC), and the rate control group received atrioventricular node ablation, if needed. The primary end-point was 12-month BiVp% (NCT). Results 43 patients were included in the analysis. The mean age was 68.4 (SD: ± 8.3) years and the mean BiVp% 82.4% ± 9.7%. AF lasted 25 ± 19 months. The mean baseline left ventricular ejection fraction (LVEF), left atrium area, and the maximal oxygen uptake (VO2max) were: 30 ± 8%, 33 ± 7 cm2, and 14 ± 5 mL/(kg*min), respectively. The EC success rate was 58%. 38% patients remained in sinus rhythm (SR) after 12 months. BiVp% increased similarly in both arms reaching 99% [95% CI 97.3–99.8] and 98% [94.0–99.0], P = 0.14 in rhythm and rate control groups, respectively. LVEF raised significantly only in the rhythm control group (ΔLVEF 4.1 (± 7.3), P = 0,018) which was driven by the patients who maintained SR. No differences in VO2max, QoL, clinical and safety end-points were observed. Conclusion Despite comparable BiVp% in both groups, only restoration of SR led to improved left ventricular ejection fraction in CRT patients with long-standing AF. Trial registration NCT01850277 registered on 22/04/2013.

Association Between use of an Adaptive Cardiac Resynchronization Therapy Algorithm and Healthcare Utilization and Cost

To assess the association between use of adaptive pacing on clinical and economic outcomes of CRT recipients in a real-world analysis. The AdaptivCRTTM algorithm was shown in prior subgroup analyses of prospective trials to achieve clinical benefits, but a large prospective trial showed nonsignificant changes in the endpoint of mortality or heart failure hospitalizations. CRT-implanted patients from the Optum Clinformatics® database with ≥90 days of follow-up were included. Remote monitoring data was used to classify patients based on CRT setting - adaptive biventricular and left ventricular pacing (aCRT) vs. standard biventricular pacing (Standard CRT). Inverse probability of treatment weighting was used to adjust for baseline differences between groups. Mortality, 30-day readmissions, healthcare utilization, and payer and patient costs were evaluated post-implantation. This study included 2,412 aCRT and 1,638 Standard CRT patients (mean follow-up: 2.4 ± 1.4 years), with balanced baseline characteristics after adjustment. The aCRT group was associated with lower all-cause mortality (adjusted hazard ratio = 0.88 [95% confidence interval (CI):0.80, 0.96]), fewer all-cause 30-day readmissions (adjusted incidence rate ratio = 0.87 [CI:0.81, 0.94]), and fewer all-cause and HF-related inpatient, outpatient, and emergency department (ED) visits. The aCRT cohort was also associated with lower all-cause outpatient payer-paid amounts and lower all-cause and HF-related inpatient and ED patient-paid amounts. In this retrospective analysis of a large real-world cohort, use of an adaptive CRT algorithm was associated with lower mortality, reduced healthcare resource utilization, and lower payer and patient costs. While cardiac resynchronization therapy (CRT) improves quality of life and clinical outcomes for certain heart failure patients, some patients do not respond to this therapy. Adaptive CRT algorithms (aCRT), such as AdaptivCRTTM, have been developed with the goal of improving effectiveness of CRT, and consequently, clinical and economic outcomes. This research study used a large database of administrative claims data - which contains information on patient demographics, diagnoses, healthcare services received, mortality, and cost data - to compare clinical and economic outcomes between CRT patients with the aCRT algorithm turned on (aCRT group) and CRT patients with the aCRT algorithm turned off (standard CRT group). Statistical methods were used to adjust for baseline differences between the aCRT group and standard CRT groups. Ultimately, the aCRT group was found to have a lower risk of all-cause mortality, fewer all-cause 30-day readmissions, fewer hospital visits (including inpatient, outpatient, and emergency department visits), and lower costs to payers and patients for specific types of costs.

Clinical Impact of Digitalis Therapy in a Large Multicenter Cohort of CRT-Recipients.

(1) Introduction: Digitalis use in patients with severe heart failure is controversial. We assessed the effects of digitalis therapy on mortality in a large, observational study in recipients of cardiac resynchronization therapy (CRT). (2) Methods: Consecutive patients receiving a CRT-defibrillator in three European tertiary referral centers were enrolled and followed-up for a mean 37 months ± 28 months. Digitalis use was assessed at the time of CRT implantation. A multivariate Cox-regression model and propensity score matching were used to determine all-cause mortality as the primary endpoint. CRT-response (defined as improvement of ≥1 NYHA class), echocardiographic improvement (defined as improvement of LVEF of ≥ 5%) and incidence of ICD shocks and rehospitalization were assessed as secondary endpoints in a subgroup of patients. (3) Results: The study comprised 552 CRT-recipients with standard indications, including 219 patients (40%) treated with digitalis. Compared to patients without digitalis, they had more often atrial fibrillation, poorer LVEF and a higher NYHA class (all p ≤ 0.002). Crude analysis of all-cause mortality demonstrated a similar relative risk of death for patients with and without digitalis (HR = 1.14; 95% CI 0.88-1.5; p = 0.40). After adjustment for independent predictors of mortality, digitalis therapy did not alter the risk for death (adjusted HR = 1.04; 95% CI 0.75-1.45; p = 0.82). Furthermore, in comparison to 286 propensity-score-matched patients, mortality was not affected by digitalis intake (propensity-adjusted HR = 1.11; 95% CI 0.72-1.70; p = 0.64). A CRT-response was predominant in digitalis non-users, concerning both improvement of HF symptoms and LVEF (NYHA p < 0.01; LVEF p < 0.01), while patients on digitalis had more often ventricular tachyarrhythmias requiring ICD shock (p = 0.01); although, rehospitalization for cardiac reasons was significantly lower among digitalis users compared to digitalis non-users (HR = 0.58; 95% C. I. 0.40-0.85; p = 0.01). (4) Conclusions: Digitalis therapy had no effect on mortality, but was associated with a reduced response to CRT and increased susceptibility to ventricular arrhythmias requiring ICD shock treatment. Although, digitalis administration positively altered the likelihood for cardiac rehospitalization during follow-up.

Cardiac resynchronization therapy using endocardial versus trans-coronary sinus, epicardial left ventricular pacing: the Epi-Endo study

Abstract Aims Some studies have suggested that cardiac resynchronization therapy (CRT) using endocardial left ventricular (LV) pacing (Endo-CRT) is superior to a conventional transvenous, epicardial CRT (Epi-CRT). To determine whether, in CRT recipients, endocardial LV pacing is haemodynamically superior to trans-coronary vein (trans-CV) LV epicardial pacing. Methods and results At implantation patients (n=16; aged 68.9±8.32 years; 13 male) underwent Epi-CRT and Endo-CRT in basal, mid and apical myocardial segments, delivered using the trans-CS lead and an intra-cavitary, roving EP catheter to achieve juxtapositions of the epicardial and endocardial side of the LV free wall respectively. Myocardial scar was quantified using cardiovascular magnetic resonance. An acute haemodynamic response (AHR) was defined as a ≥10% increase in the maximal rate of rise of LV pressure (%LV dP/dtmax) in relation to RV pacing (DOO). When the 84 paired segments were taken together, the %ΔLV dP/dtmax was higher with Endo-CRT than with Epi-CRT (9.9±8,6% vs 7.9±8.3% respectively, p&amp;lt;0.002; 52.3% vs 28.6% responders [p&amp;lt;0.045). However, Endo-CRT was not always superior to epi-CRT in individual patients. For example, in basal segments, only 5/10 (50%) patients were converted from non-responders with epi-CRT to responders with endo-CRT whereas 1/4 (25%) epi-CRT responder was converted to a non-responder with endo-CRT (Figure). There was no difference in ΔLV dP/dtmax between Epi-CRT and endo-CRT in segments with myocardial scar. Conclusions On average, endo-CRT provides a better AHR than epi-CRT. Within patients, however, endo-CRT is not always better.Epicardial versus Endocardial CRT

Influence of multimorbidity and socioeconomic position on long-term healthcare utilization and prognosis in patients after cardiac resynchronization therapy implantation.

We aimed to investigate the influence of socioeconomic position (SEP) and multimorbidity on cross-sectional healthcare utilization and prognosis in patients after cardiac resynchronization therapy (CRT) implantation. We included first-time CRT recipients with left ventricular ejection fraction ≤35% implanted between 2000 and 2017. Data on chronic conditions, use of healthcare services, and demographics were obtained from Danish national administrative and health registries. Healthcare utilization (in- and outpatient hospitalizations, activities in general practice) was compared by multimorbidity categories and SEP by using a negative binomial regression model. The association between SEP, multimorbidity, and prognostic outcomes was analysed using Cox proportional hazards regression. We followed 2007 patients (median age of 70 years), 79% were male, 75% were on early retirement or state pension, 37% were living alone, and 41% had low education level for a median of 5.2 [inter-quartile range: 2.2-7.3) years. In adjusted regression models, a higher number of chronic conditions were associated with increased healthcare utilization. Both cardiovascular and non-cardiovascular hospital contacts were increased. Patients with low SEP had a higher number of chronic conditions, but SEP had limited influence on healthcare utilization. Patients living alone and those with low educational level had a trend towards a higher risk of all-cause mortality [adjusted hazard ratio (aHR): 1.17, 95% confidence interval (CI) 1.03-1.33, and aHR 1.09, 95% CI 0.96-1.24). Multimorbidity increased the use of cross-sectional healthcare services, whereas low SEP had minor influence on the utilizations. Living alone and low educational level showed a trend towards a higher risk of mortality after CRT implantation.

Immediate pharmacotherapy intensification after cardiac resynchronization therapy: incidence, characteristics, and impact.

Cardiac resynchronization therapy (CRT) is an established treatment for drug-refractory heart failure (HF) in patients with left bundle branch block (LBBB). Acute haemodynamic improvement after CRT implantation may enable the intensification of HF medication soon thereafter. Immediate pharmacotherapy intensification (IPI) after CRT implantation achieves a synergetic effect, possibly leading to a better prognosis. This study aimed to explore the incidence, characteristics, and impact of IPI on real-world outcomes among CRT recipients with a history of hospitalization for acute HF. This multicentre retrospective study enrolled CRT recipients with LBBB morphology, a QRS width ≥120ms, a left ventricular ejection fraction ≤35%, and New York Heart Association II-IV HF symptoms. All patients had previous HF hospitalizations within the previous year and received guideline-directed medical therapy before CRT implantation. Patient baseline characteristics, including HF medication, were collected. IPI was defined as the intensification of beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists within 30days of CRT implantation. The primary endpoint was all-cause death or first hospitalization for HF; the secondary endpoint was all-cause death. We enrolled 194 patients (75% male; mean age, 65±13years; 78% with non-ischaemic cardiomyopathy). One hundred five (54%) patients received IPI. Patients who received IPI exhibited a significantly shorter QRS duration (159±26 vs. 171±32ms; P=0.004), higher estimated glomerular filtration rate (55.2±20.0 vs. 47.8±24.7mL/min/1.73m2; P=0.022), and more dilated cardiomyopathy. During a median follow-up period of 29months, 70 (36%) patients reached the primary endpoint and 42 (22%) patients died. Patients with IPI showed significantly better outcomes for the primary and secondary endpoints than patients without IPI. The volumetric responder ratio at 6months after implantation was not significantly different between patients with and without IPI; however, patients who received IPI had reduced mortality even at 6months after implantation. In the multivariate analysis, IPI was an independent predictor of the primary endpoint (hazard ratio, 0.51; 95% confidence interval, 0.27-0.97; P=0.043). Immediate intensification of HF medication was achieved in 54% of CRT recipients and was significantly higher in patients without excessive QRS prolongation, preserved renal function, and dilated cardiomyopathy than others. In patients with LBBB morphology and QRS≥120ms, IPI was associated with a significantly better prognosis and fewer HF hospitalizations after CRT implantation than others.

Multicenter Study of Survival Benefit of Cardiac Resynchronization Therapy in Pediatric and Congenital Heart Disease

BackgroundEvidence for the efficacy of cardiac resynchronization therapy (CRT) in pediatric and congenital heart disease (CHD) has been limited to surrogate outcomes. ObjectivesThis study aimed to assess the impact of CRT upon the risk of transplantation or death in a retrospective, high-risk, controlled cohort at 5 quaternary referral centers. MethodsBoth CRT patients and control patients were <21 years of age or had CHD; had systemic ventricular ejection fraction <45%; symptomatic heart failure; and significant electrical dyssynchrony (QRS duration z score >3 or single-site ventricular pacing >40%) at enrollment. Patients with CRT were matched with control patients via 1:1 propensity score matching. CRT patients were enrolled at CRT implantation; control patients were enrolled at the outpatient clinical encounter where inclusion criteria were first met. The primary endpoint was transplantation or death. ResultsIn total, 324 control patients and 167 CRT recipients were identified. Mean follow-up was 4.2 ± 3.7 years. Upon propensity score matching, 139 closely matched pairs were identified (20 baseline indices). Of the 139 matched pairs, 52 (37.0%) control patients and 31 (22.0%) CRT recipients reached the primary endpoint. On both unadjusted and multivariable Cox regression analysis, the risk reduction associated with CRT for the primary endpoint was significant (HR: 0.40; 95% CI: 0.25-0.64; P < 0.001; and HR: 0.44; 95% CI: 0.28-0.71; P = 0.001, respectively). On longitudinal assessment, the CRT group had significantly improved systemic ventricular ejection fraction (P < 0.001) and shorter QRS duration (P = 0.015), sustained to 5 years. ConclusionsIn pediatric and CHD patients with symptomatic systolic heart failure and electrical dyssynchrony, CRT was associated with improved heart transplantation-free survival.

Cardiac Magnetic Resonance Identifies Responders to Cardiac Resynchronization Therapy with an Assessment of Septal Scar and Left Ventricular Dyssynchrony.

Background: The response to cardiac resynchronization therapy (CRT) depends on septal viability and correction of abnormal septal motion. This study investigates if cardiac magnetic resonance (CMR) as a single modality can identify CRT responders with combined imaging of pathological septal motion (septal flash) and septal scar. Methods: In a prospective, multicenter, observational study of 136 CRT recipients, septal scar was assessed using late gadolinium enhancement (LGE) (n = 127) and septal flash visually from cine CMR sequences. The primary endpoint was CRT response, defined as ≥15% reduction in LV end-systolic volume with echocardiography after 6 months. The secondary endpoint was heart transplantation or death of any cause assessed after 39 ± 13 months. Results: Septal scar and septal flash were independent predictors of CRT response in multivariable analysis (both p < 0.001), while QRS duration and morphology were not. The combined approach of septal scar and septal flash predicted CRT response with an area under the curve of 0.86 (95% confidence interval (CI): 0.78-0.94) and was a strong predictor of long-term survival without heart transplantation (hazard ratio 0.27, 95% CI: 0.10-0.79). The accuracy of the approach was similar in the subgroup with intermediate (130-150 ms) QRS duration. The combined approach was superior to septal scar and septal flash alone (p < 0.01). Conclusions: The combined assessment of septal scar and septal flash using CMR as a single-image modality identifies CRT responders with high accuracy and predicts long-term survival.

Changes in medical therapy after cardiac resynchronization in patients with heart failure: insights from the U.S. Veterans Affairs healthcare system

Abstract Background Patients with heart failure with reduced ejection fraction (HFrEF) are often not treated with comprehensive guideline directed medical therapy (GDMT) due to hemodynamic and renal limitations. Cardiac resynchronization therapy (CRT) improves hemodynamics in patients with HFrEF and ventricular dyssynchrony. Whether CRT facilitates intensification of GDMT in patients with HFrEF has not been well-studied. Purpose To assess pre-procedure GDMT (B-blocker, ACEI [angiotensin converting enzyme inhibitor]/ARB [angiotensin receptor blocker], ARNI [angiotensin receptor neprilysin inhibitor], MRA [mineralocorticoid receptor antagonist], SGLT2i [sodium-glucose cotransporter-2 inhibitor]) utilization in HFrEF patients who received CRT and to compare changes in GDMT in patients who received CRT with patients who received implantable cardioverter-defibrillator (ICD). Methods Veterans with left ventricular ejection fraction (LVEF) 35% who received CRT or ICD from Feb 22, 2000 – Jul 28, 2022 were identified. Patients with end-stage renal disease were excluded. Changes in GDMT 12-months following device implant were characterized and compared between CRT and ICD recipients. Mixed effects logistic regression models were generated to evaluate associations between receipt of CRT and the composite of therapy initiation, dose increase, or target dose achievement compared with ICD. Models were adjusted for clinical characteristics and pre-implant GDMT utilization. Similar models were developed to evaluate the adjusted associations between CRT and changes in estimated glomerular filtration rate (eGFR) and blood pressure (BP) compared with ICD. Results A total of 2,082 CRT recipients and 7,263 ICD recipients were identified. Pre-procedure heart rate, BP, serum potassium, and eGFR were within normal ranges and similar between groups. Prior to device implant, ACEI/ARB/ARNI were most frequently prescribed (91%), followed by -blockers (88%), MRA (46%), and SGLT2i (33% in post-SGLT2i era). Pre-procedure GDMT was similar between CRT and ICD recipients. At 12 months follow-up, CRT was independently associated with increased odds of therapy initiation, dose increase, or target dose achievement for ACEI/ARB/ARNI, ARNI, B-blockers, and MRA (Figure 1). ICD was associated with a decline in eGFR while CRT was associated with an increase in eGFR (mean [standard deviation]: -0.95 [0.17] vs. +0.6 [0.29]; p&amp;lt;0.01), while no differences were observed in BP or LVEF at 12 months. Conclusions In a large, contemporary cohort of patients with HFrEF, most patients were not prescribed MRA or SGLT2i prior to receiving CRT or ICD despite no apparent renal or blood pressure-related contraindications. CRT is associated with increased odds of the composite of initiation, dose increase, or target dose achievement for ACEI/ARB/ARNI, ARNI, B-blockers, and MRA compared with ICD. GDMT intensification may be mediated by beneficial changes in kidney function in CRT recipients.Figure 1

Abstract 17896: Implantable Cardioverter Defibrillator in Cardiac Resynchronization Therapy Recipients With Advanced Chronic Kidney Disease

Introduction: The effectiveness of the implantable cardioverter defibrillator (ICD) in preventing sudden cardiac death (SCD) is well-established in heart failure patients with reduced ejection fraction (HFrEF). However, the benefit of the ICD in advanced chronic kidney disease (CKD) patients remains elusive, particularly in those who are cardiac resynchronization therapy (CRT) recipients. Hypothesis: In CRT recipients with CKD, the benefit of the ICD may be attenuated due to the competing risk of mortality before experiencing an arrhythmia. Methods: A total of 1015 patients receiving CRT with defibrillator (CRT-D) for primary prevention of SCD were included from the MADIT-CRT and RAID trials. Patients were categorized into two groups based on kidney disease (KD) stage: Stage 1-3a (S1-S3a) CKD and Stage 3b-5 (S3b-S5) CKD. The primary endpoint was the occurrence of ventricular tachycardia (VT) or ventricular fibrillation (VF). Results: The cumulative incidence of any VT/VF was 23.5% in patients with (S1-S3a)KD and 12.6% in those with (S3b-S5)KD (p&lt;0.001 [Figure left panel]). Death without VT/VF occurred in 6.6% of patients with (S1-S3a)KD and 21.6% of patients with( S3b-S5)KD (p&lt;0.001 [Figure right panel]). A multivariate competing risk regression model revealed that patients with (S3b-S5)KD had a 43% lower risk of experiencing any VT/VF compared to those with (S1-S3a)KD (HR=0.56, 95% CI [0.33-0.94], p=0.03). Over two years of follow-up, patients with (S3b-S5)KD had nearly a five-fold increased risk of death without VT/VF compared to those with (S1-S3a)KD (HR=4.63, 95% CI [2.46-8.72], p for interaction with time=0.012). Conclusions: The benefit of the ICD may be attenuated in CRT recipients with advanced CKD due to a lower incidence of arrhythmias and a higher risk of non-arrhythmic death. Future prospective trials should investigate whether CRT without a defibrillator is more suitable for these patients.

Abstract 16252: A Survival Analysis in Patients With Tricuspid Regurgitation and Cardiac Resynchronization Therapy

Introduction: Cardiac resynchronization therapy (CRT) is a well established treatment in heart failure with reduced ejection fraction. It involves simultaneous pacing of the left and right ventricles to restore ventricular synchrony, leading to increased cardiac output and contractility. The impact of CRT on tricuspid regurgitation (TR) severity has not been evaluated. Studies have shown that up to 22% of CRT recipients have significant TR, and of these patients only 41% will improve to no or mild TR. For a majority of patients who have persistent significant TR despite CRT, long term outcomes are put into question. Hypothesis: Tricuspid regurgitation adversely affects the response and survival of CRT patients. Goals: To analyze the prevalence of TR in a cohort of patients admitted to The Christ Hospital who have undergone CRT. To assess the association between TR after CRT and long-term survivability. Methods: This is a retrospective cohort study conducted at The Christ Hospital in Cincinnati Ohio. 13292 patients diagnosed with tricuspid regurgitation (mild to severe) in total were included. 184 of these patients underwent CRT, and survival probability was measured against the no CRT group. Kaplan meier method was used for analysis. Results: Survival probabilities at 1 year, 2 years, and 3 years for patients with CRT = 0.769, 0.661, and 0.558 respectively. Patients without CRT = 0.911, 0.863, and 0.826 respectively. Hazard ratio = 2.84 (2.33, 3.47) compared to solely tricuspid regurgitation. Conclusions: Patients with TR without CRT had greater survival rates up to three years compared to TR with CRT. The risk of death in the TR with CRT was 2.84 times higher than the no CRT group. It can be further investigated why the no CRT group had a greater survival rate than CRT. Limitations include variable assessments of TR due to the subjective nature of grading TR. Future research could investigate the difference between primary (device-related) and secondary TR in this cohort.

N-terminal pro atrial natriuretic peptide as a prognostic marker of cardiac resynchronization therapy recipients

BackgroundAlthough the dynamic changes of atrial natriuretic peptide (ANP) expressions in a failing heart are well-documented, the clinical implications of detailed measurements of each ANP molecular form processed from proANP remain unclear. MethodsPatients screening was conducted on patients who were eligible for cardiac resynchronization therapy (CRT) between 2014 and 2019 in our institution. Blood samples and echocardiographic parameters were collected on the day before and six months after implantation. Total ANP, proANP, and N-terminal fragment of proANP (NT-proANP) were examined as predictive biomarkers for cardiac death, left ventricular assist device implantation, and heart failure hospitalization following CRT implantation. ResultsA total of 86 subjects (mean age 70 years, 64 males) who underwent successful CRT implantation were enrolled. Plasma levels of total ANP, proANP, and NT-proANP were not normally distributed [25.8 pM (interquartile range: 11.1–53.1), 2.2 pM (1.0–5.4), and 4.1 nM (2.4–7.1), respectively]. Over a median follow-up of 2.7 years, 31 patients (2 deaths and 29 heart failure hospitalizations) reached the endpoints. Among the different ANP forms, only NT-proANP emerged as an independent predictor of the composite outcome (adjusted odds ratio of 2.542 in those with levels above vs. below the median, 95 % confidence interval 1.151–5.615, p = 0.021). NT-proANP levels were associated with left atrial volume and left diastolic functional parameters and decreased in response to echocardiographic improvements at six months post-implantation (16 ± 44 % decrease in responders vs 18 ± 60 % increase in non-responders, p = 0.005). ConclusionPre-implantation NT-proANP levels could serve as a predictive factor for clinical outcomes in recipients of CRT.

Evolution of Echocardiography-Derived Hemodynamic Force Parameters After Cardiac Resynchronization Therapy

Echocardiography-derived hemodynamic forces (HDF) allow calculation of intraventricular pressure gradients from routine transthoracic echocardiographic images. The evolution of HDF after cardiac resynchronization therapy (CRT) has not been investigated in large cohorts. The aim was to assess HDF in patients with heart failure implanted with CRT versus healthy controls. HDF were assessed before and 6months after CRT. The following HDF parameters were calculated: (1) apical-basal strength, (2) lateral-septal strength, (3) the ratio of lateral-septal to apical-basal strength ratio, and (4) the force vector angle (1 and 2 representing the magnitude of HDF, 3 and 4 representing the orientation of HDF). In the propulsive phase of systole, the apical-basal impulse and the systolic force vector angle were measured. A total of 197 patients were included (age 64 ± 11years, 62% male), with left ventricular ejection fraction ≤35%, QRS duration ≥130ms and left bundle branch block. The magnitude of HDF was significantly lower and the orientation was significantly worse in patients with heart failure versus healthy controls. Immediately after CRT implantation, the apical-basal impulse and systolic force vector angle were significantly increased. Six months after CRT, improvement of apical-basal strength, lateral-septal to apical-basal strength ratio and the force vector angle occurred. When CRT was deactivated at 6months, the increase in the magnitude of apical-basal HDF remained unchanged while the systolic force vector angle worsened significantly. In conclusion, HDF in CRT recipients reflect the acute effect of CRT and the effect of left ventricular reverse remodeling on intraventricular pressure gradients. Whether HDF analysis provides incremental value over established echocardiographic parameters, remains to be determined.

Echocardiographic mechanical dyssynchrony predicts long-term mortality in patients with cardiac resynchronisation therapy

Cardiac resynchronisation therapy (CRT) is an established treatment for patients with symptomatic heart failure with reduced left ventricular ejection fraction (LVEF ≤ 35%; HFrEF) and conduction disturbances (QRS duration ≥ 130 ms). The presence of mechanical dyssynchrony (MD) on echocardiography has been hypothesised to be of predictive value in determining indication for CRT. This study investigated the impact of MD (apical rocking [AR] and septal flash [SF]) on long-term survival in CRT recipients. HFrEF patients (n = 425; mean age 63.0 ± 10.6 years, 72.3% male, 60.7% non-ischaemic aetiology) with a guideline-derived indication for CRT underwent device implantation. MD markers were determined at baseline and after a mean follow-up of 11.5 ± 8.0 months; long-term survival was also determined. AR and/or SF were present in 307 (72.2%) participants at baseline. During post-CRT follow-up, AR and/or SF disappeared in 256 (83.4%) patients. Overall mean survival was 95.9 ± 52.9 months, longer in women than in men (109.1 ± 52.4 vs. 90.9 ± 52.4 months; p < 0.001) and in younger (< 60 years) versus older patients (110.6 ± 53.7 vs. 88.6 ± 51.1 months; p < 0.001). Patients with versus without MD markers at baseline generally survived for longer (106.2 ± 52.0 vs. 68.9 ± 45.4 months; p < 0.001), and survival was best in patients with resolved versus persisting MD (111.6 ± 51.2 vs. 79.7 ± 47.6 months p < 0.001). Age and MD at baseline were strong predictors of long-term survival in HFrEF patients undergoing CRT on multivariate analysis. Novel echocardiography MD parameters in HFrEF CRT recipients predicted long-term mediated better outcome, and survival improved further when AR and/or SF disappear after CRT implantation.Graphical abstract

Impact of sacubitril/valsartan and gliflozins on cardiac resynchronization therapy response in ischemic and non-ischemic heart failure patients

AimsAngiotensin receptor-neprilysin inhibitor (ARNi) and sodium-glucose co-transporter 2 inhibitor (SGLT2i) improve outcomes in heart failure with reduced ejection fraction (HFrEF) patients, however their effects in cardiac resynchronization therapy (CRT) recipients have been scarcely explored. This study investigated whether ARNi and SGLT2i 1) improve the rate of clinical and echocardiographic CRT response and 2) have different impact based on the ischemic or non-ischemic etiology. MethodsHFrEF patients referred for CRT implant were grouped in no treatment (group 1), only ARNi (group 2) and both ARNi and SGLT2i (group 3). Clinical and echocardiographic response were evaluated at 12 months. ResultsA total of 178 patients were enrolled. At one-year follow-up, 74.4% patients in group 2 (p = 0.031) and 88.9% in group 3 (p = 0.014) were classified as clinical responders vs 54.5% in the no treatments group. In multivariable analysis, ARNi/SGLT2i use was an independent predictor of CRT response (OR 3.72; CI 95%, 1.40–10.98; p = 0.011), confirmed in both groups 2 and 3. At 12 months, the median Δ LVEF increase was 6% and 8.5% in groups 2 and 3 respectively, vs 4.5% in group 1 (p = 0.042 and p = 0.029) with significantly more echocardiographic responders in groups 2 and 3 (76% and 78% vs 50%, p = 0.003 and p = 0.036). Significantly more ischemic HFrEF patients than non-ischemic were considered clinical and echocardiographic responders in the treatment groups. ConclusionsARNi alone or in combination with SGLT2i in CRT patients improves the clinical and echocardiographic response at 12 months. Ischemic patients seem to benefit more from these treatments.

Mechanical Dyssynchrony Combined with Septal Scarring Reliably Identifies Responders to Cardiac Resynchronization Therapy.

Background and aim: The presence of mechanical dyssynchrony on echocardiography is associated with reverse remodelling and decreased mortality after cardiac resynchronization therapy (CRT). Contrarily, myocardial scar reduces the effect of CRT. This study investigated how well a combined assessment of different markers of mechanical dyssynchrony and scarring identifies CRT responders. Methods: In a prospective multicentre study of 170 CRT recipients, septal flash (SF), apical rocking (ApRock), systolic stretch index (SSI), and lateral-to-septal (LW-S) work differences were assessed using echocardiography. Myocardial scarring was quantified using cardiac magnetic resonance imaging (CMR) or excluded based on a coronary angiogram and clinical history. The primary endpoint was a CRT response, defined as a ≥15% reduction in LV end-systolic volume 12 months after implantation. The secondary endpoint was time-to-death. Results: The combined assessment of mechanical dyssynchrony and septal scarring showed AUCs ranging between 0.81 (95%CI: 0.74-0.88) and 0.86 (95%CI: 0.79-0.91) for predicting a CRT response, without significant differences between the markers, but significantly higher than mechanical dyssynchrony alone. QRS morphology, QRS duration, and LV ejection fraction were not superior in their prediction. Predictive power was similar in the subgroups of patients with ischemic cardiomyopathy. The combined assessments significantly predicted all-cause mortality at 44 ± 13 months after CRT with a hazard ratio ranging from 0.28 (95%CI: 0.12-0.67) to 0.20 (95%CI: 0.08-0.49). Conclusions: The combined assessment of mechanical dyssynchrony and septal scarring identified CRT responders with high predictive power. Both visual and quantitative markers were highly feasible and demonstrated similar results. This work demonstrates the value of imaging LV mechanics and scarring in CRT candidates, which can already be achieved in a clinical routine.

Primary prevention implantable cardioverter defibrillator in cardiac resynchronization therapy recipients with advanced chronic kidney disease.

The implantable cardioverter defibrillator (ICD) is effective for the prevention of sudden cardiac death (SCD) in patients with heart failure and a reduced ejection fraction (HFrEF). The benefit of the ICD in patients with advanced CKD, remains elusive. Moreover, the benefit of the ICD in patients with advanced chronic kidney disease (CKD) and HFrEF who are cardiac resynchronization therapy (CRT) recipients may be attenuated. We hypothesized that patients with CKD who are CRT recipients may derive less benefit from the ICD due to the competing risk of dying prior to experiencing an arrhythmia. The study population included 1,015 patients receiving CRT with defibrillator (CRT-D) device for primary prevention of SCD who were enrolled in either (Multicenter Automated Defibrillator Implantation Trial) MADIT-CRT trial or the Ranolazine in High-Risk Patients with Implanted Cardioverter Defibrillator (RAID) trial. The cohort was divided into two groups based on the stage of CKD: those with Stage 1 to 3a KD, labeled as (S1-S3a)KD. The second group included patients with Stage 3b to stage 5 kidney disease, labeled as (S3b-S5)KD. The primary endpoint was any ventricular tachycardia (VT) or ventricular fibrillation (VF) (Any VT/VF). The cumulative incidence of Any VT/VF was 23.5% in patients with (S1-S3a)KD and 12.6% in those with (S3b-S5)KD (p < 0.001) The incidence of Death without Any VT/VF was 6.6% in patients with (S1-S3a)KD and 21.6% in patients with (S3b-S5)KD (p < 0.001). A Fine and Gray multivariate competing risk regression model showed that Patients with (S3b-S5)KD had a 43% less risk of experiencing Any VT/VF when compared to those with (S1-S3a)KD (HR = 0.56, 95% CI [0.33-0.94] p = 0.03. After two years of follow up, there was almost a 5-fold increased risk of Death without Any VT/VF among patients with (S3b-S5)KD when compared to those with (S1-S3a)KD [HR = 4.63, 95% CI (2.46-8.72), p for interaction with time = 0.012]. Due to their lower incidence of arrhythmias and higher risk of dying prior to experiencing an arrhythmia, the benefit of the ICD may be attenuated in CRT recipients with advanced CKD. Future prospective trials should evaluate whether CRT without a defibrillator may be more appropriate for these patients.

Targeted left ventricular lead positioning to the site of latest activation in cardiac resynchronization therapy: a systematic review and meta-analysis.

Several studies have evaluated the use of electrically- or imaging-guided left ventricular (LV) lead placement in cardiac resynchronization therapy (CRT) recipients. We aimed to assess evidence for a guided strategy that targets LV lead position to the site of latest LV activation. A systematic review and meta-analysis was performed for randomized controlled trials (RCTs) until March 2023 that evaluated electrically- or imaging-guided LV lead positioning on clinical and echocardiographic outcomes. The primary endpoint was a composite of all-cause mortality and heart failure hospitalization, and secondary endpoints were quality of life, 6-min walk test (6MWT), QRS duration, LV end-systolic volume, and LV ejection fraction. We included eight RCTs that comprised 1323 patients. Six RCTs compared guided strategy (n = 638) to routine (n = 468), and two RCTs compared different guiding strategies head-to-head: electrically- (n = 111) vs. imaging-guided (n = 106). Compared to routine, a guided strategy did not significantly reduce the risk of the primary endpoint after 12-24 (RR 0.83, 95% CI 0.52-1.33) months. A guided strategy was associated with slight improvement in 6MWT distance after 6 months of follow-up of absolute 18 (95% CI 6-30) m between groups, but not in remaining secondary endpoints. None of the secondary endpoints differed between the guided strategies. In this study, a CRT implantation strategy that targets the latest LV activation did not improve survival or reduce heart failure hospitalizations.

Combination of personalized computational modeling and machine learning for optimization of left ventricular pacing site in cardiac resynchronization therapy.

Introduction: The 30-50% non-response rate to cardiac resynchronization therapy (CRT) calls for improved patient selection and optimized pacing lead placement. The study aimed to develop a novel technique using patient-specific cardiac models and machine learning (ML) to predict an optimal left ventricular (LV) pacing site (ML-PS) that maximizes the likelihood of LV ejection fraction (LVEF) improvement in a given CRT candidate. To validate the approach, we evaluated whether the distance DPS between the clinical LV pacing site (ref-PS) and ML-PS is associated with improved response rate and magnitude. Materials and methods: We reviewed retrospective data for 57 CRT recipients. A positive response was defined as a more than 10% LVEF improvement. Personalized models of ventricular activation and ECG were created from MRI and CT images. The characteristics of ventricular activation during intrinsic rhythm and biventricular (BiV) pacing with ref-PS were derived from the models and used in combination with clinical data to train supervised ML classifiers. The best logistic regression model classified CRT responders with a high accuracy of 0.77 (ROC AUC = 0.84). The LR classifier, model simulations and Bayesian optimization with Gaussian process regression were combined to identify an optimal ML-PS that maximizes the ML-score of CRT response over the LV surface in each patient. Results: The optimal ML-PS improved the ML-score by 17 ± 14% over the ref-PS. Twenty percent of the non-responders were reclassified as positive at ML-PS. Selection of positive patients with a max ML-score >0.5 demonstrated an improved clinical response rate. The distance DPS was shorter in the responders. The max ML-score and DPS were found to be strong predictors of CRT response (ROC AUC = 0.85). In the group with max ML-score > 0.5 and DPS< 30 mm, the response rate was 83% compared to 14% in the rest of the cohort. LVEF improvement in this group was higher than in the other patients (16 ± 8% vs. 7 ± 8%). Conclusion: A new technique combining clinical data, personalized heart modelling and supervised ML demonstrates the potential for use in clinical practice to assist in optimizing patient selection and predicting optimal LV pacing lead position in HF candidates for CRT.

Mechanical dyssynchrony combined with septal scarring reliably identifies responders to cardiac resynchronization therapy

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Research Foundation Flanders (FWO). Background The presence of mechanical dyssynchrony on echocardiography is associated with reverse remodeling after cardiac resynchronization therapy (CRT). In contrast, recent studies suggest that presence of myocardial scarring – particularly in the septal wall – reduces the effect of CRT. Recently, a combined assessment of mechanical dyssynchrony and septal wall scarring has demonstrated high predictive power for CRT response. However, a direct comparison of different markers of mechanical dyssynchrony has not yet been performed. Aim This study: (I) investigated how well a combined assessment of different markers of mechanical dyssynchrony and septal scarring identifies responders to CRT, and (II) evaluated potential differences in predictive power. Methods In a prospective multicentre study in 170 CRT recipients, septal flash (SF) or apical rocking (ApRock), systolic stretch index (SSI) and lateral-to-septal (LW-S) work difference were assessed on echocardiography. SSI was calculated from longitudinal strain traces of the four-chamber view as the sum of the septal systolic stretch and lateral systolic pre-stretch before aortic valve closure. The LW-S work difference was calculated from the regional work of the lateral wall and septal wall - considering the averaged work from the basal- and mid-ventricular segments in the apical four-chamber view. Myocardial scarring of the septum was quantified on cardiac magnetic resonance imaging (CMR) late gadolinium enhancement (LGE) images (n=125 patients), or excluded based on a coronary angiogram and clinical history (n=45 patients). Myocardial scarring was reported regionally as percentage of total amount of scarred tissue per wall. The study’s endpoint was CRT response, defined as ≥15% reduction in LV end-systolic volume 12 months after CRT implantation. AUC’s from ROC curves were used to investigate the predictive power of the different markers for CRT response. Results The AUC’s for the combined assessment of the markers of mechanical dyssynchrony and septal scarring as predictor of CRT-response were 0.86 (95% CI: 0.79–0.91) for presence of SF or ApRock, 0.81 (95% CI: 0.74–0.88) for SSI, and 0.84 (95% CI: 0.76–0.90) for LW-S work difference (all p&amp;lt;0.0001). No significant difference was observed between the different markers of mechanical dyssynchrony (p&amp;gt;0.05 between all). Conclusions The combined assessment of mechanical dyssynchrony and septal scarring identified CRT responders with high predictive power. Both visual and quantitative markers demonstrated similar results. Our data demonstrates the importance of assessing LV mechanics and scarring in CRT-candidates, which can easily be achieved in clinical routine.