Invasive Hemodynamic Assessment Research Articles

Definition, classification and diagnosis of pulmonary hypertension.

Pulmonary hypertension (PH) is a haemodynamic condition characterised by elevation of mean pulmonary arterial pressure (mPAP) >20 mmHg, assessed by right heart catheterisation. Pulmonary arterial wedge pressure (PAWP) and pulmonary vascular resistance (PVR) distinguish pre-capillary PH (PAWP ≤15 mmHg, PVR >2 Wood Units (WU)), isolated post-capillary PH (PAWP >15 mmHg, PVR ≤2 WU) and combined post- and pre-capillary PH (PAWP >15 mmHg, PVR >2 WU). Exercise PH is a haemodynamic condition describing a normal mPAP at rest with an abnormal increase of mPAP during exercise, defined as a mPAP/cardiac output slope >3 mmHg/L/min between rest and exercise. The core structure of the clinical classification of PH has been retained, including the five major groups. However, some changes are presented herewith, such as the re-introduction of "long-term responders to calcium channel blockers" as a subgroup of idiopathic pulmonary arterial hypertension, the addition of subgroups in group 2 PH and the differentiation of group 3 PH subgroups based on pulmonary diseases instead of functional abnormalities. Mitomycin-C and carfilzomib have been added to the list of drugs with "definite association" with PAH. For diagnosis of PH, we propose a stepwise approach with the main aim of discerning those patients who need to be referred to a PH centre and who should undergo invasive haemodynamic assessment. In case of high probability of severe pulmonary vascular disease, especially if there are signs of right heart failure, a fast-track referral to a PH centre is recommended at any point during the clinical workup.

Additive value of invasive haemodynamic assessment for predicting post-operative outcomes after Fontan.

Routine pre-Fontan cardiac catheterization remains standard practice at most centres. However, with advances in non-invasive risk assessment, an invasive haemodynamic assessment may not be necessary for all patients.Using retrospective data from patients undergoing Fontan palliation at our institution, we developed a multivariable model to predict the likelihood of a composite adverse post-operative outcome including prolonged length of stay ≥ 30 days, hospital readmission within 6 months, and death and/or transplant within 6 months. Our baseline model included non-invasive risk factors obtained from clinical history and echocardiogram. We then incrementally incorporated invasive haemodynamic data to determine if these variables improved risk prediction.Our baseline model correctly predicted favourable versus adverse post-Fontan outcomes in 118/174 (68%) patients. Covariates associated with adverse outcomes included the presence of a systemic right ventricle (adjusted adds ratio [aOR] 2.9; 95% CI 1.4, 5.8; p = 0.004), earlier surgical era (aOR 3.1 for era 1 vs 2; 95% CI 1.5, 6.5; p = 0.002), and performance of concomitant surgical procedures at the time of Fontan surgery (aOR 2.5; 95% CI 1.1, 5.0; p = 0.026). Incremental addition of invasively acquired haemodynamic data did not improve model performance or percentage of outcomes predicted.Invasively acquired haemodynamic data does not add substantially to non-invasive risk stratification in the majority of patients. Pre-Fontan catheterization may still be beneficial for angiographic evaluation of anatomy, for therapeutic intervention, and in select patients with equivocal risk stratification.

Future of invasive and non-invasive hemodynamic assessment for coronary artery disease management.

Coronary artery disease represents a global health challenge. Accurate diagnosis and evaluation of hemodynamic parameters are crucial for optimizing patient management and outcomes. Nowadays a wide range of both non-invasive and invasive methods are available to assess the hemodynamic impact of both epicardial coronary stenosis and vasomotor disorders. In fact, over the years, important developments have reshaped the nature of both invasive and non-invasive diagnostic techniques, and the future holds promises for further innovation and integration. Non-invasive techniques have progressively evolved and currently a broad spectrum of methods are available, from cardiac magnetic resonance imaging with pharmacological stress and coronary computed tomography (CT) to the newer application of FFR-CT and perfusion CT. Invasive methods, on the contrary, have developed to a full-physiology approach, able not only to identify functionally significant lesions but also to evaluate microcirculation and vasospastic disease. The aim of this review is to summarize the current state-of-the-art of invasive and non-invasive hemodynamic assessment for CAD management.

A patient with pulmonary hypertension: a rare case of AL amyloidosis involving the heart and external auditory canal

The article presents a case of immunoglobulin light chain amyloidosis with cardiac involvement without typical noncardiac manifestations. A complex diagnostic search for the cause of newly diagnosed pulmonary hypertension is described. Aspects of differential diagnosis in invasive hemodynamic assessment of pulmonary circulation and echocardiographic data are discussed. A special case feature is involvement of the hearing organ, which is very rare.

Evaluating the hemodynamic impact of saddle versus non-saddle pulmonary embolism: insights from a thrombectomy cohort.

The aim of this study was to compare the hemodynamic impact and clinical outcomes of saddle vs non-saddle pulmonary embolism (PE). This was a retrospective analysis of clinical characteristics and outcomes among patients with saddle and non-saddle PE within a cohort referred for catheter-based thrombectomy (CBT) with invasive hemodynamic assessments. Patients who underwent CBT between August 2020 and January 2024 were included. The primary outcome was the proportion of patients with a low cardiac index (CI < 2.2 L/min/m²). Secondary outcomes included 30-day mortality, intensive care unit (ICU) length of stay (LOS), and hospital LOS. A total of 107 patients (84 intermediate risk, 23 high-risk; mean age 58 years, 47.6% female) were included in the study, with 44 patients having saddle PE and 63 having non-saddle PE. There were no significant differences in baseline demographics and clinical characteristics between saddle and non-saddle PE, including rates of high-risk PE (25% vs 16%, P = .24), rates of RV dysfunction, pulmonary artery systolic pressure (55 vs 53 mm Hg, P = .74), mean pulmonary artery pressure (34 mm Hg vs 33 mm Hg), low cardiac index (56% vs 51%, P = .64), rates of normotensive shock (27% vs 20%, P = .44), or Composite Pulmonary Embolism Shock scores (4.5 vs 4.7, P = .25). Additionally, 30-day mortality (6% vs 5%, P = .69), ICU LOS, and hospital LOS were similar between the groups. Among patients undergoing CBT, there were no significant differences in invasive hemodynamic parameters or clinical outcomes between those with saddle and non-saddle PE.

A multimodal approach to predict prosthesis-patient mismatch in patients undergoing valve-in-valve trans-catheter aortic valve implantation

AimsThe valve-in-valve transcatheter-aortic-valve-implantation (VIV-TAVI) represents an emerging procedure for the treatment of degenerated aortic bio-prostheses, and the occurrence of patient-prosthesis mismatch (PPM) after VIV-TAVI might affect its clinical efficacy. This study aimed to test a multimodal imaging approach to predict PPM risk during the TAVI planning phase and assess its clinical predictivity in VIV-TAVI procedures. MethodsConsecutive patients undergoing VIV-TAVI procedures at our Institution over 6 years were screened and those treated by self-expandable supra-annular valves were selected. The effective orifice area (EOA) was calculated with a hybrid Gorlin equation combining echocardiographic data with invasive hemodynamic assessment. Severe PPM was defined according to such original multimodality assessment as EOAi≤0.65 cm2/m2 (if BMI < 30 kg/m2) or < 0.55 cm2/m2 (if BMI ≥ 30 kg/m2). The primary endpoint was a composite of all-cause mortality and valve-related re-hospitalization during the clinical follow-up. ResultsA total of 40 VIV-TAVI was included in the analysis. According to the pre-specified multimodal imaging modality assessment, 18 patients (45.0 %) had severe PPM. Among all baseline clinical and anatomical characteristics, estimated glomerular filtration rate before VIV-TAVI (OR 0.872, 95%CI[0.765–0.994],p = 0.040), the echocardiographic pre-procedural ≥moderate AR (OR 0.023, 95%CI[0.001–0.964],p = 0.048), the MSCT-derived effective internal area (OR 0.958, 95%CI[0.919–0.999],p = 0.046) and the implantation depth (OR 2.050, 95%CI[1.028–4.086],p = 0.041) resulted as independent predictors of severe PPM at multivariable logistic analysis. At a mean follow-up of 630 days, patients with severe PPM showed a higher incidence of the primary endpoint (9.1%vs.44.4 %;p = 0.023). ConclusionIn VIV-TAVI using self-expandable supra-annular valves, a multimodal imaging approach might improve clinical outcome predicting severe PPM occurrence.

AORTIC REGURGITATION INDEX IDENTIFIES SIGNIFICANT AORTIC REGURGITATION DURING IMPELLA SUPPORT FOR CARDIOGENIC SHOCK

Abstract Background Aortic regurgitation (AR) significantly hampers the unloading effect and the antegrade flow enhancement expected from the micro–axial flow pump Impella (Abiomed, Danvers). To date, no dedicated hemodynamic index is available to inform on the severity of AR during Impella support. Methods We included 100 patients receiving Impella support for CS with invasive hemodynamic assessment with pulmonary artery catheter (PAC). PAC measures were obtained 48 hours after Impella support initiation. AR grading was performed by either trans–thoracic or trans–esophageal echocardiography in the following strata: 0–none; 1–mild; 2–moderate; 3–moderate–severe; 4–severe. Study cohort was dichotomized according to AR severity≥2+. Several relevant hemodynamic indexes were validated against echocardiographic AR assessment to identify those mostly associated with significant AR (AR severity≥2+), including: AR index [ARI, calculated as (diastolic arterial pressure – pulmonary artery wedge pressure)/systolic arterial pressure, abbreviated in (DAP–PAWP)/SAP], diastolic pulse pressure (DPP, calculated as DAP–PAWP), MAP–adjuster ARI [ARIMAP calculated as (diastolic arterial pressure – pulmonary artery wedge pressure)/mean arterial pressure, abbreviated in (DAP–PAWP)/MAP)]. Results Significant AR (≥2+) was found in 31% patients. Patients with AR≥2+ had higher values of pulmonary artery wedge pressure (PAWP) after 48 hours from support initiation [15 (12, 21) vs 12 (10, 16) mmHg; p&amp;lt;0.021]. Several invasive hemodynamic indexes differentiated AR≥2+ vs AR&amp;lt;2 patients, including: ARI [0.42 (0.36, 0.51) vs 0.50 (0.44, 0.61); p&amp;lt;0.001], DPP [47 (37, 58) vs 57 (48.00, 68) mmHg; p=0.003] and ARIMAP [0.62 (0.54, 0.70) vs 0.70 (0.64, 0.75); p=0.005] (Figure 1). ARI demonstrated the strongest association and the greatest accuracy in identifying AR≥2+ (area under the curve 0.73; 95%CI: 0.61–0.85; p=0.002). The threshold of ARI 0.39 had excellent specificity (88.0%) and moderate sensitivity (62.9%), Figure 2. Conclusions The easy–to–use ARI metric [(DAP–PAWP)/SAP] accurately identifies patients with significant AR during Impella support, at the optimal cutoff of ARI 0.39. This index may be complementary to echocardiography in the assessment of AR during Impella support.

Pulmonary artery elastance as a predictor of hospital mortality in heart failure cardiogenic shock.

The initial bundle of cares strongly affects haemodynamics and outcomes in acute decompensated heart failure cardiogenic shock (ADHF-CS). We sought to characterize whether 24h haemodynamic profiling provides superior prognostic information as compared with admission assessment and which haemodynamic parameters best predict in-hospital death. All patients with ADHF-CS and with available admission and 24h invasive haemodynamic assessment from two academic institutions were considered for this study. The primary endpoint was in-hospital death. Regression analyses were run to identify relevant predictors of study outcome. We included 127 ADHF-CS patients [65 (inter-quartile range 52-72) years, 25.2% female]. Overall, in-hospital mortality occurred in 26.8%. Non-survivors were older, with greater CS severity. Among admission variables, age [odds ratio (OR)=1.06; 95% confidence interval (CI): 1.02-1.11; Padj=0.005] and CPIRAP (OR=0.62 for 0.1 increment; 95% CI: 0.39-0.95; Padj=0.034) were found significantly associated with in-hospital death. Among 24h haemodynamic univariate predictors of in-hospital death, pulmonary elastance (PaE) was the strongest (area under the curve of 0.77; 95% CI: 0.68-0.86). PaE (OR=5.98; 95% CI: 2.29-17.48; Padj<0.001), pulmonary artery pulsatility index (PAPi, OR=0.77; 95% CI: 0.62-0.92; Padj=0.013) and age (OR=1.06; 95% CI: 1.02-1.11; Padj=0.010) were independently associated with in-hospital death. Best cut-off for PaE was 0.85mmHg/mL and for PAPi was 2.95; cohort phenotyping based on these PaE and PAPi thresholds further increased in-hospital death risk stratification; patients with 24h high PaE and low PAPi exhibited the highest in-hospital mortality (56.2%). Pulmonary artery elastance has been found to be the most powerful 24h haemodynamic predictor of in-hospital death in patients with ADHF-CS. Age, 24h PaE, and PAPi are independently associated with hospital mortality. PaE captures right ventriclar (RV) afterload mismatch and PAPi provides a metric of RV adaptation, thus their combination generates four distinct haemodynamic phenotypes, enhancing in-hospital death risk stratification.

C-1 | "The Impact of Pulmonary Hypertension on Survival in Carcinoid Heart Disease: Insights from Invasive Hemodynamic Assessment"

C-1 | "The Impact of Pulmonary Hypertension on Survival in Carcinoid Heart Disease: Insights from Invasive Hemodynamic Assessment"

Novel Strategies in Diagnosing Heart Failure with Preserved Ejection Fraction: A Comprehensive Literature Review.

Heart failure (HF) with preserved ejection fraction (HFpEF) is a prevalent global condition affecting approximately 50% of the HF population. With the aging of the worldwide population, its incidence and prevalence are expected to rise even further. Unfortunately, until recently, no effective medications were available to reduce the high mortality and hospitalization rates associated with HFpEF, making it a significant unmet need in cardiovascular medicine. Although HFpEF is commonly defined as HF with normal ejection fraction and elevated left ventricular filling pressure, performing invasive hemodynamic assessments on every individual suspected of having HFpEF is neither feasible nor practical. Consequently, several clinical criteria and diagnostic tools have been proposed to aid in diagnosing HFpEF. Overall, these criteria and tools are designed to assist healthcare professionals in identifying and evaluating patients who may have HFpEF based on a combination of signs, symptoms, biomarkers, and non-invasive imaging findings. By employing these non-invasive diagnostic approaches, clinicians can make informed decisions regarding the best pharmacological and rehabilitation strategies for individuals with suspected HFpEF. This literature review aims to provide an overview of all currently available methods for diagnosing and monitoring this disabling condition.

Coronary Microvascular Disease Registry (CMDR): Study design and rationale

BackgroundCoronary microvascular dysfunction (CMD) is a prevalent condition among patients with cardiovascular risk factors, leading to a reduced quality of life and an increased risk of major adverse cardiovascular events. Novel invasive techniques have emerged to more accurately diagnose CMD. However, CMD's natural history remains poorly understood due to limited data. To address this knowledge gap, the Coronary Microvascular Disease Registry (CMDR) was established with the primary aim of standardizing comprehensive coronary functional testing and understanding of CMD. DesignCMDR is a prospective, multicenter registry enrolling an unlimited number of consecutive subjects who undergo comprehensive invasive hemodynamic assessment of the entire coronary arterial vasculature. Patients undergoing acetylcholine provocation test for coronary vasospasm will also be included. Follow-up assessments will be conducted at 30 days and annually for up to 5 years. The primary endpoint is Canadian Cardiovascular Society angina grade over time. Secondary endpoints, including all-cause mortality, cardiovascular death, acute myocardial infarction, stroke, hospitalizations, medication changes, and subsequent coronary interventions, will be analyzed to establish long-term safety and clinical outcomes in patients undergoing invasive CMD assessment. SummaryCMDR aims to characterize the clinical and physiologic profile of patients undergoing comprehensive invasive coronary functional testing, simultaneously providing crucial longitudinal information on the natural history and outcomes of these patients. This will shed light on CMD's course and clinical implications, which, in turn, holds the potential to significantly improve diagnostic and treatment strategies for CMD patients, ultimately leading to the enhancement of their overall prognosis and quality of life. Clinical trial registrationclinicaltrials.gov, NCT05960474

Mitral Annulus Calcium Score in Patients With Calcific Mitral Stenosis Undergoing Invasive Hemodynamic Assessment.

Aortic valve calcium score is associated with hemodynamic severity of aortic stenosis. Whether this association is present in calcific mitral stenosis remains unknown. This study was a retrospective analysis of consecutive patients with mitral stenosis secondary to mitral annular calcification (MAC) undergoing transseptal catheterization. All patients underwent invasive mitral valve assessment via direct left atrial and left ventricular pressure measurement. Computed tomography within 1 year of cardiac catheterization and with adequate visualization of the mitral annulus was included. MAC calcium score quantification by Agatston method was obtained offline using dedicated software (Aquarius, TeraRecon, V.4). Median patient age was 66.9±11.2 years, 47% of patients were women, 50% had coronary artery disease, 40% had atrial fibrillation, 47% had prior cardiac surgery, and 33% had prior chest radiation. Median diastolic mitral valve gradient was 9.4±3.4 mm Hg on echocardiography and 8.5±4 mm Hg invasively. Invasive median mitral valve area using the Gorlin formula was 1.87±0.9 cm2. Median MAC calcium score for the cohort was 7280±7937 Hounsfield units. MAC calcium score correlated with the presence of atrial fibrillation (P=0.02) but was not associated with other comorbidities. There was no correlation between MAC calcium score and mitral valve area (r=0.07; P=0.6) or mitral valve gradient (r=-0.03; P=0.8). MAC calcium score did not correlate with invasively measured mitral valve gradient and mitral valve area in patients with MAC-related mitral stenosis, suggesting that calcium score should not be used as a surrogate for invasive hemodynamic parameters.

Lead Dislodgement Post Invasive Hemodynamic Assessment after Atrioventricular Node Ablation and Biventricular Pacemaker

A man with history of Heart Failure with preserved Ejection Fraction (HFpEF), Atrioventricular (AV) node ablation followed by biventricular pacemaker placement was hospitalized for dyspnea. During invasive hemodynamic assessment patient had brief episode of asystole due to lead displacement. Right catheterization should be cautiously performed in patients with intracardiac devices, when done safety protocols should be followed.

Pulmonary vascular dysfunction in systemic sclerosis

PurposeThis study aimed to determine if any cases of pulmonary arterial hypertension (PAH) were missed using routine screening of systemic sclerosis (SSc). We assessed the potential benefits of adding the DETECT algorithm and invasive hemodynamic exercise testing into the local screening process in a Danish single-center cohort without known PAH. MethodsSeventy-three SSc patients (aged 60 ± 10 years; 56 (77%) females) underwent echocardiography. Among them, 24/73 had an elevated STEP 2 score of whom 3 had a high risk of pulmonary hypertension on echocardiographic assessment. Four patients declined right heart catheterization. Twenty patients (aged 62 ± 10 years, 13 (65%) females) underwent invasive haemodynamic assessment at rest. Nineteen patients participated in invasive haemodynamic exercise testing. ResultsAt rest, 3/20 patients met the 2022 ESC guidelines for PAH (mean pulmonary arterial pressure (mPAP) > 20 mmHg, pulmonary arterial wedge pressure (PAWP) ≤ 15 mmHg, and pulmonary vascular resistance (PVR) > 2 Wood units). According to the 2015 ESC guidelines, only 1/19 patients had PAH. During exercise, 18/19 experienced a mPAP of > 30 mmHg, with the majority (13/19) showing an abnormal pulmonary pressure-flow relationship > 3 mmHg/L/min. Interestingly, seven out of nine patients with no pulmonary hypertension (PH) at rest had exercise-induced pulmonary hypertension. One-quarter of the patients had pulmonary hypertension associated with left ventricular dysfunction (Group 2 PH, WHO classification). ConclusionIn a Danish cohort of 73 SSc patients already undergoing bi-annual PAH screening, applying the DETECT algorithm identified three patients meeting the 2022 ESC/ERS guideline criteria for PAH at rest, one of whom demonstrated increased PAWP with exercise. However, many patients exhibited an abnormal pulmonary vascular response to exercise and/or signs of Group 2 PH.

Impact of right ventricular to pulmonary artery coupling on remodeling and outcome in patients undergoing transcatheter edge-to-edge mitral valve repair

Abstract Background Right ventricular to pulmonary artery (RV-PA) coupling has recently been shown to be associated with outcome in valvular heart disease. However, longitudinal data on RV dysfunction and reverse cardiac remodeling in patients following transcatheter edge-to-edge mitral valve repair (M-TEER) are scarce. Methods Consecutive patients with primary as well as secondary mitral regurgitation (MR) were prospectively enrolled and had comprehensive echocardiographic and invasive hemodynamic assessment at baseline. Kaplan-Meier estimates and multivariable Cox-regression analyses were performed using a composite endpoint of heart failure hospitalization and death. Results Between April 2018 to January 2021, 156 patients (median 78 y/o, 55% female, EuroSCORE II: 6.9%) underwent M-TEER. On presentation, 64% showed impaired RV-PA coupling defined as tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) ratio &amp;lt;0.36. Event-free survival rates at 2 years were significantly lower among patients with impaired coupling (57 vs. 82%, p&amp;lt;0.01), both in patients with primary (64 vs. 91%, p=0.01) and secondary MR (54 vs. 76%, p=0.03). On multivariable Cox-regression analyses adjusted for baseline, imaging, hemodynamic, and procedural data, TAPSE/PASP ratio &amp;lt;0.36 was independently associated with outcome (adj.HR 2.74, 95%CI: 1.17-6.43, p=0.02). At 1-year follow-up, RV-PA coupling improved (TAPSE: ∆ +3mm, PASP: ∆ -10mmHg, p for both &amp;lt;0.01), alongside with a reduction in tricuspid regurgitation (TR) severity (grade ≥II: 77 to 54%, p&amp;lt;0.01). Conclusion TAPSE/PASP ratio was associated with outcome in patients undergoing M-TEER for primary as well as secondary MR. RV-PA coupling, alongside with TR severity, improved after M-TEER and might thus provide prognostic information in addition to established markers of poor outcome.Graphical Abstract

Invasively diagnosed HFpEF in AF associated with functional remodelling of the left atrial appendage: implications for stroke risk

Abstract Background HFpEF commonly coexists with atrial fibrillation (AF). The influence of coexisting HFpEF on function of the left atrial appendage (LAA) and risk of stroke remains unknown. Objective To use invasive hemodynamic assessment and multi-modality imaging to evaluate the influence of underlying HFpEF on LAA function in patients with symptomatic AF. Methods Patients with AF and preserved ejection fraction undergoing AF ablation were prospectively recruited. All participants underwent invasive diagnosis of HFpEF using established hemodynamic criteria. Participants were classified as ‘HFpEF’ when mean left atrial pressure (mLAP) was &amp;gt;15mmHg and ‘early HFpEF’ when mLAP rose to above 15mmHG after infusion of 500mls saline. For LAA assessment, participants underwent 1) contrast-enhanced cardiac CT to evaluate LAA volume, 2) transesophageal echocardiography to investigate emptying velocities (LAAEV), filling velocities (LAAFV) and LAA ejection fraction (LAAEF) and 3) high-density electroanatomic mapping to assess LAA bipolar voltages. Results Of 115 participants recruited, 55 had ‘HFpEF’, whilst 29 had ‘early HFpEF’ and 31 had ‘no HFpEF’. Table 1 demonstrates the baseline characteristics and LAA structural and functional parameters across the three groups. The HFpEF group was characterized by higher BMI (p=0.008) and higher prevalence of hypertension (p=0.023) but there was no significant difference in age (p=0.194) or gender (p=0.376). LAA volume was not significantly different across the three groups (p=0.509). However, the HFpEF group demonstrated reduced LAAEV (p=0.021) and LAAFV (p=0.015) compared to early HFpEF and no HFpEF. HFpEF was also associated with reduced LAAEF (p=0.015) and reduced LAA bipolar voltages in sinus rhythm (p=0.028) compared to no HFpEF. In a multivariable analysis HFpEF group was the only independent predictor of reduced LAAEV (p=0.015). Conclusions Invasively diagnosed HFpEF in AF is common and associated with significantly reduced LAA function. The coexistence of HFpEF may therefore be a determinant of future stroke risk in patients with AF.

Abstract 18770: Understanding Patients’ Characteristics and Coronary Microvasculature: Early Insights From First US Coronary Microvascular Dysfunction Registry

Introduction: Coronary angiography falls short in accurately evaluating the coronary microcirculation. Fortunately, a new comprehensive invasive hemodynamic assessment method, which uses coronary flow reserve (CFR) and the index of microvascular resistance (IMR), provides enhanced diagnostic capabilities. Objective: We present our early real-world experience with invasive hemodynamic assessment of the coronary microvasculature in symptomatic patients with non-obstructive coronary artery disease (CAD) from the first US Coronary Microvascular Disease Registry (CMDR). Methods: The CMDR is a prospective, multi-center, standardized registry of patients with angina and non-obstructive CAD who underwent invasive hemodynamic assessment of the coronary microvasculature using the Coroventis CoroFlow Cardiovascular System (Abbott Laboratories, Chicago, Illinois). Comprehensive assessments, including resting full-cycle ratio (RFR), fractional flow reserve (FFR), CFR, and IMR, were performed on all patients. Results: The first 156 patients enrolled in the CMDR were analyzed; their mean age was 62.4 years and 65.6% were female. A substantial proportion (31.8%) of patients presented with a Canadian Cardiovascular Society Angina Score of 3 or 4. CMD was diagnosed in 39 of 154 patients (25.3%), with mean RFR of 0.89±0.43, mean FFR of 0.93±0.08, mean CFR of 1.8±0.9, and mean IMR of 36.26±19.23. None of the patients experienced in-hospital adverse events. Conclusions: Early results from CMDR patients show that invasive hemodynamic assessment of the coronary microvasculature is safe and effective for suspected CMD. Tailored medical therapy for microvascular angina was provided to diagnosed CMD patients. With ongoing patient enrollment, the CMDR aims to contribute valuable insights to the growing evidence base for CMD.

Abstract 17833: Characterization of Central versus Peripheral Predominance of Exercise Limitation in Patients With Heart Failure and Preserved Ejection Fraction

Background: Heart failure with preserved ejection fraction (HFpEF) is a heterogenous disorder in which abnormalities in both cardiac output (CO) and peripheral oxygen extraction (CavO 2 ) contribute to impaired oxygen uptake (VO 2 ). We investigated the predominant limitation to VO 2 , according to distinct HFpEF criteria, by examining the CO vs. VO 2 relationship during incremental exercise. Methods: Participants underwent Cardiopulmonary Exercise Testing (CPET) with invasive hemodynamic assessment and were diagnosed with HFpEF based on characteristic symptoms and NTproBNP ≥125pg/mL, Supine PCWP ≥15mmHg, PCWP/CO ≥2mmHg/L/min or Peak PCWP ≥25mmHg. Calculated direct Fick CO versus VO 2 slope and peak exercise data were stratified by the expected relationship of CO(L/min) = 5хVO 2 (L/min) +5. The Mann Whitney U Test and t-test characterized those limited by cardiac output (Slope &lt;5L/min) vs. peripheral extraction (Slope &gt;5L/min). Results: In 425 dyspneic individuals meeting biomarker and/or hemodynamic criteria for HFpEF, 36% had predominantly peripheral limitation (Measured Peak CO &gt; Expected). Among those with NTpro-BNP ≥125pg/mL or resting PCWP ≥15mmHg, or both (N=220) , 31% were peripherally limited. 41% of those with a PCWP/CO ≥2mmHg/mL/min or Peak PCWP ≥25mmHg, or both (N=205) , were peripherally limited. Among all peripherally limited patients (N=151), the percentage of females, NTpro-BNP levels, Hb levels, rest and peak Ca-vO 2 , and rest and peak PVR were significantly lower compared to the cardiac limited group (Table, N=274), while resting PCWP, LVEF and HR were similar (Table). Conclusion: Despite meeting concurrent biomarker and/or hemodynamic criteria for HFpEF, peripheral-predominant limitation to exercise capacity is common which merits consideration when deploying interventions to augment exercise capacity in HFpEF.

Abstract 15999: Proportional Pulse Pressure and Shock Index as Predictors of Cardiac Index in Patients With Intermediate-Risk Pulmonary Embolism

Background: Risk stratification in intermediate-risk pulmonary embolism (PE) plays an important role in appropriate selection of therapies, however this is often challenging given variable phenotype. Proportional pulse pressure (PPP) and shock index (SI) have demonstrated to accurately predict cardiac index (CI) in patients with cardiogenic shock. Nonetheless, their applicability to patients with acute PE remains uncertain. Our objective is to investigate whether PPP and SI correlate with invasive assessment of CI in intermediate-risk PE. Methods: We retrospectively analyzed patients included in the Pulmonary Embolism Response Team (PERT) registry at NYCH+H/Bellevue who underwent invasive hemodynamic assessment. PPP was calculated as systolic blood pressure - diastolic blood pressure/systolic blood pressure. SI was calculated as heart rate/systolic blood pressure. Linear regression and correlation coefficients were used to examine the relationship between PPP, SI and CI as well as other clinical variables. Results: A total of 45 intermediate-risk PE patients were included (mean age was 57 ± 13 years and 43% were female). The SI moderately correlated with the composite pulmonary embolism shock score (CPES) (r = 0.5, p=0.0002), sPESI (r = 0.37, p=0.007), cardiac index (-0.42, p=0.004) and poorly correlated with lactate levels (r=0.23, p=0.18). PPP correlated poorly with CPES (r = 0.01, p=0.96), sPESI (r = -0.04, p=0.73), CI (r = 0.1 p=0.51) and lactate (-0.18, p=0.2). There was poor correlation between SI and PPP (r = -0.17, p=0.23). For every 0.1 increase in the shock index, the cardiac index was lower by 0.17L/minute/m 2 (p=0.017). Conclusions: In patients with intermediate-risk PE, a higher SI was associated with a lower CI, while PPP was not associated with CI. SI may provide additional valuable information to risk-stratify patients with acute PE and can potentially assist clinicians in triaging monitoring level therapeutic decisions.

Impact of right ventricular-to-pulmonary artery coupling on remodeling and outcome in patients undergoing transcatheter edge-to-edge mitral valve repair.

Right ventricular-to-pulmonary artery (RV-PA) coupling has recently been shown to be associated with outcome in valvular heart disease. However, longitudinal data on RV dysfunction and reverse cardiac remodeling in patients following transcatheter edge-to-edge mitral valve repair (M-TEER) are scarce. Consecutive patients with primary as well as secondary mitral regurgitation (MR) were prospectively enrolled and had comprehensive echocardiographic and invasive hemodynamic assessment at baseline. Kaplan-Meier estimates and multivariable Cox-regression analyses were performed, using a composite endpoint of heart failure hospitalization and death. Between April 2018 and January 2021, 156 patients (median 78 y/o, 55% female, EuroSCORE II: 6.9%) underwent M-TEER. On presentation, 64% showed impaired RV-PA coupling defined as tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) ratio < 0.36. Event-free survival rates at 2years were significantly lower among patients with impaired coupling (57 vs. 82%, p < 0.001), both in patients with primary (64 vs. 91%, p = 0.009) and secondary MR (54 vs. 76%, p = 0.026). On multivariable Cox-regression analyses adjusted for baseline, imaging, hemodynamic, and procedural data, TAPSE/PASP ratio < 0.36 was independently associated with outcome (adj.HR 2.74, 95% CI 1.17-6.43, p = 0.021). At 1-year follow-up, RV-PA coupling improved (TAPSE: ∆ + 3mm, PASP: ∆ - 10mmHg, p for both < 0.001), alongside with a reduction in tricuspid regurgitation (TR) severity (grade ≥ II: 77-54%, p < 0.001). TAPSE/PASP ratio was associated with outcome in patients undergoing M-TEER for primary as well as secondary MR. RV-PA coupling, alongside with TR severity, improved after M-TEER and might thus provide prognostic information in addition to established markers of poor outcome.