Borlaug, Barry A

Subjective and objective limitations to exercise and activity are hallmarks of heart failure (HF), regardless of underlying ejection fraction (EF). These limitations relate to cardiovascular abnormalities involving the systolic and diastolic properties of the heart, venous, and arterial vasculature, as well as noncardiovascular abnormalities, including impairments in pulmonary function, autonomic regulation, anemia, metabolism, and changes in mitochondria and skeletal muscle. The contribution of these abnormalities varies between patients with HF with preserved EF and those with HF with reduced EF, but, even within each HF subtype, there is substantial individual patient pathophysiologic variability, which suggests a potentially important role for phenotyping based on exercise reserve responses to individualize treatment. In this article, we review the current understanding of exercise reserve limitation with a focus on specific organ systems involved, both in patients with HF with preserved EF and HF with reduced EF, and how these interact to lead to symptoms of exercise intolerance and objective limitations in submaximal and peak aerobic capacity across the spectrum of HF.

BACKGROUND: Patients with lung disease, sleep apnea, and chronic thromboemboli can develop pulmonary hypertension, currently classified as group 3 or 4. Many of these patients also have risk factors for heart failure with preserved ejection fraction (HFpEF), but the optimal approach to identify the disease overlap remains unclear. METHODS: Pretest probability for HFpEF was determined using the HFpEF-ABA (age, body mass index, atrial fibrillation) algorithm among adjudicated group 3 or 4 patients at risk for pulmonary hypertension in the PVDOMICS study (Redefining Pulmonary Hypertension Through Pulmonary Vascular Disease Phenomics). Patients were stratified by current resting right heart catheterization criteria, and in a separate analysis, stratified only by HFpEF-ABA probability into low (<25%), intermediate, and high (≥75%) HFpEF probability groups. RESULTS: Among 598 patients with group 3 disease, 27% (n=161) had elevated pulmonary capillary wedge pressure (PCWP) with postcapillary pulmonary hypertension even at rest, which was associated with the highest exercise PCWP. However, regardless of this resting PCWP-based classification, a larger subset had intermediate-to-high HFpEF-ABA probabilities (32% [n=197] high and 57% [n=358] intermediate HFpEF probability). High HFpEF probability in group 3 disease was associated with higher resting and dynamic PCWP response to NO, fluid, and exercise ( P <0.0001 for all). These changes were comparable with more traditionally defined HFpEF without pulmonary vascular disease (n=61) but less severe than those with combined precapillary and postcapillary pulmonary hypertension HFpEF (n=31; interaction P =0.006). Increasing HFpEF probability in group 3 disease was associated with worse left heart remodeling, quality of life, 6-minute walk distance, and peak VO 2 ( P <0.0001 for all). Findings were replicated in group 4 disease (n=102). CONCLUSIONS: Quantifying pretest probability for HFpEF in patients with sleep apnea, lung disease, or chronic thromboemboli identifies a progressive gradient for dynamic PCWP abnormalities with worse functional status and quality of life. These subclinical left heart abnormalities are not universally detectable by resting right heart catheterization alone and call for further study of whether strategies to prevent or treat HFpEF might improve functional status in these patients with high risk of occult HFpEF.

ABSTRACT Background Incident atrial functional mitral regurgitation (AFMR) is associated with mortality. Transcatheter edge‐to‐edge repair (TEER) has shown effectiveness in improving MR and symptoms in AFMR, but previous studies lacked comparison to conservative management. We aimed to study the association of AFMR severity and mitral TEER with symptoms, heart failure hospitalizations (HFH) and all‐cause mortality in moderate/severe AFMR. Methods Consecutive adults with moderate/severe AFMR managed conservatively or with TEER 2010−2023 were identified retrospectively. To ensure similar technique in evaluation in the two groups, variables were obtained from the closest transthoracic echocardiogram before TEER in the TEER group. In addition to multivariable analysis, the association of TEER (vs. conservative management) with HFH and mortality was assessed using propensity‐score matched analyses; the propensity score was based on age, sex, EuroSCORE II, effective regurgitant orifice area, integrative MR severity, and NYHA class III/IV (vs. I/II). Results Among 230 patients with moderate/severe AFMR [mean age 77; 56% females], 46 were managed with TEER. Severe (vs. moderate) AFMR was independently associated with baseline NYHA class III/IV (multivariable OR 2.18 [95% CI 1.13−4.26]) and HFH [multivariable HR 2.75 (95% CI 1.25−6.03)] but not mortality ( p = 0.26). TEER improved MR to ≤ moderate in 93% but was not associated with lower HFH or death rates versus conservative management on multivariable or matched analysis. However, 1‐year NYHA improved more with TEER versus conservative management in patients with baseline NYHA class III/IV (62% vs. 27%, p = 0.03). Rhythm control was associated with improved survival (HR 0.38 [0.15−0.98]). Conclusions AFMR severity was associated with symptoms and HFH but not mortality. MR severity and NYHA class improved with TEER, but the association of TEER with HF hospitalizations or death remains unproven. Randomized studies are needed to evaluate the potential role of TEER and rhythm control on outcomes in AFMR.

BACKGROUND: Despite favorable hemodynamic and neurohormonal effects, endothelin receptor antagonists have not improved outcomes in patients with heart failure (HF), possibly because they cause fluid retention. METHODS: In this randomized, double-blind, multicenter trial (SERENADE [Macitentan in Heart Failure With Preserved Ejection Fraction and Pulmonary Vascular Disease]), we evaluated the effects of an endothelin receptor antagonist, macitentan, in patients with HF, left ventricular ejection fraction ≥40%, and pulmonary vascular disease. After a 4-week placebo run-in (to ensure clinical stability), followed by a 5-week single-blind macitentan run-in, patients who did not exhibit fluid retention were randomized to macitentan or placebo. The primary end point was change in NT-proBNP (N-terminal pro-B-type natriuretic peptide; baseline to 24 weeks); secondary end points included change in KCCQ (Kansas City Cardiomyopathy Questionnaire) clinical summary score (baseline to 24 weeks) and time to worsening HF by 52 weeks. RESULTS: Of 230 patients enrolled, 28 were excluded during the placebo run-in, 60 excluded during the macitentan run-in, and 142 were randomized. Macitentan had no effect on change in NT-proBNP (geometric mean ratio [macitentan/placebo], 1.02 [90% CI, 0.88–1.19]; P =0.79) or on secondary end points (placebo-corrected change in KCCQ clinical summary score, −3.5 [90% CI, −8.2 to +1.2]; P =0.22). Worsening HF occurred in 20 (28%) patients assigned to macitentan and 13 (18%) assigned to placebo (hazard ratio, 1.48 [90% CI, 0.83–2.67]; P =0.24). More macitentan-treated patients developed fluid retention (16 [23%] versus 10 [14%]) and cardiac adverse events (33 [46%] versus 22 [31%]) versus placebo. CONCLUSIONS: Despite a novel enrichment trial design to target pulmonary vascular disease and exclude treatment-related fluid retention in patients with HF and preserved/mildly reduced left ventricular ejection fraction, macitentan neither lowered NT-proBNP nor improved HF outcomes. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifiers: NCT03153111 and NCT03714815.

BACKGROUND: Exercise-induced hypertension (EIH) is common in adults with coarctation of the aorta (COA), but there are limited data about hemodynamics and outcomes in such patients. The purpose of this study was to assess changes in arterial load during exercise in patients with COA with versus without EIH, and the relationship to clinical outcomes. METHODS: We compared Doppler-derived arterial load indices (effective arterial elastance index, total arterial compliance index, systemic vascular resistance index), and clinical indices of disease severity (pulmonary congestion, aerobic capacity, and cardiovascular biomarkers) between adults with repaired COA and healthy controls. EIH was defined as systolic blood pressure (BP) at peak exercise >210 mm Hg in men or >190 mm Hg in women. RESULTS: In this prospective cohort study, we assessed patients with COA (n=41, age 43±14 years, 26 [63%] men) and healthy controls (n=41). Although both groups had similar resting systolic BP, the COA group had higher Doppler-derived arterial load indices at rest, as well as a greater rise in systolic BP and Doppler-derived arterial load indices at each stage of exercise, leading to a higher prevalence of EIH in the COA group (37% versus 10%; P =0.004). Compared with patients with COA without EIH (n=26, 63%), those with EIH had higher arterial load at rest and during exercise, as well as worse cardiac dysfunction, pulmonary congestion, and biomarkers of cardiovascular remodeling, despite no significant differences in resting systolic BP. CONCLUSIONS: BP assessment during exercise can improve risk stratification and identify patients who may benefit from intensification of medical therapy.

Abstract Heart failure with reduced or preserved ejection fraction is associated with elevated left atrial pressure at rest due to fluid overload or during exercise, leading to pulmonary venous congestion. Even with available treatments, heart failure hospitalizations remain high, and improvements in quality-of-life scores and functional capacity are modest. Thus, there is growing interest in non-pharmacological methods to decompress the left atrium and improve heart failure symptoms and outcomes. Left-to-right shunts have emerged as a potential therapeutic option to reduce left atrial hypertension, improve quality of life, and impact long-term outcomes. This nascent field carries both potential therapeutic promise and many unanswered questions. Recent data have questioned whether the effects of this therapy vary based on the left ventricular ejection fraction, pulmonary vascular resistance, and/or right ventricular structure and function. This review discusses the basis for left-to-right shunt therapies, synthesizes past and ongoing clinical trials, and offers future directions.

Background The immune response to infections may become dysregulated and promote myocardial damage contributing to heart failure (HF). We examined the relationship between infection‐related hospitalization (IRH) and HF, HF with preserved ejection fraction, and HF with reduced ejection fraction. Methods and Results We studied 14 468 adults aged 45 to 64 years in the ARIC (Atherosclerosis Risk in Communities) Study who were HF free at visit 1 (1987–1989). IRH was identified using select International Classification of Diseases ( ICD ) codes in hospital discharge records and was treated as a time‐varying exposure. HF incidence was defined as the first occurrence of either a hospitalization that included an ICD, Ninth Revision ( ICD‐9 ) discharge code of 428 (428.0–428.9) among the primary or secondary diagnoses or a death certificate with an ICD‐9 code of 428 or an ICD, Tenth Revision ( ICD‐10 ) code of I50 among any of the listed diagnoses or underlying causes of death. We used multivariable‐adjusted Cox proportional hazards models to assess the association between IRH and incident HF, HF with reduced ejection fraction, and HF with preserved ejection fraction. Median follow‐up time was 27 years, 55% were women, 26% were Black, mean age at baseline was 54±6 years, 46% had an IRH, and 3565 had incident HF. Hazard ratio (HR) for incident HF events among participants who had an IRH compared with those who did not was 2.35 (95% CI, 2.19–2.52). This relationship was consistent across different types of infections. Additionally, IRH was associated with both HF with reduced ejection fraction and HF with preserved ejection fraction: 1.77 (95% CI, 1.35–2.32) and 2.97 (95% CI, 2.36–3.75), respectively. Conclusions IRH was associated with incident HF, HF with reduced ejection fraction, and HF with preserved ejection fraction. IRH might represent a modifiable risk factor for HF pathophysiology.