McNulty, Steven E.

Background— Atrial fibrillation (AF) is common among patients with heart failure and preserved ejection fraction (HFpEF), but its clinical profile and impact on exercise capacity remain unclear. RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in HFpEF) was a multicenter randomized trial testing the impact of sildenafil on peak V O 2 in stable outpatients with chronic HFpEF. We sought to compare clinical features and exercise capacity among patients with HFpEF who were in sinus rhythm (SR) or AF. Methods and Results— RELAX enrolled 216 patients with HFpEF, of whom 79 (37%) were in AF, 124 (57%) in SR, and 13 in other rhythms. Participants underwent baseline cardiopulmonary exercise testing, echocardiogram, biomarker assessment, and rhythm status assessment before randomization. Patients with AF were older than those in SR but had similar symptom severity, comorbidities, and renal function. β-blocker use and chronotropic indices were also similar. Despite comparable left ventricular size and mass, AF was associated with worse systolic (lower EF, stroke volume, and cardiac index) and diastolic (shorter deceleration time and larger left atria) function compared with SR. Pulmonary artery systolic pressure was higher in AF. Patients with AF had higher N-terminal pro-B-type natriuretic peptide, aldosterone, endothelin-1, troponin I, and C-telopeptide for type I collagen levels, suggesting more severe neurohumoral activation, myocyte necrosis, and fibrosis. Peak V O 2 was lower in AF, even after adjustment for age, sex, and chronotropic response, and V E /V CO 2 was higher. Conclusions— AF identifies an HFpEF cohort with more advanced disease and significantly reduced exercise capacity. These data suggest that evaluation of the impact of different rate or rhythm control strategies on exercise tolerance in patients with HFpEF and AF is warranted. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00763867.

Background— Congestion is a primary driver of symptoms in patients with acute heart failure, and relief of congestion is a critical goal of therapy. Monitoring of response to therapy through the assessment of daily weights and net fluid loss is the current standard of care, yet the relationship between commonly used markers of decongestion and both patient reported symptom relief and clinical outcomes are unknown. Methods and Results— We performed a retrospective analysis of the randomized clinical trial, Diuretic Optimization Strategy Evaluation in Acute Heart Failure (DOSE-AHF), enrolling patients hospitalized with a diagnosis of acute decompensated heart failure. We assessed the relationship among 3 markers of decongestion at 72 hours—weight loss, net fluid loss, and percent reduction in serum N terminal B-type natriuretic peptide (NT-proBNP) level—and relief of symptoms as defined by the dyspnea visual analog scale area under the curve. We also determined the relationship between each marker of decongestion and 60-day clinical outcomes defined as time to death, first rehospitalization or emergency department visit. Mean age was 66 years, mean ejection fraction was 35%, and 27% had ejection fraction ≥50%. Of the 3 measures of decongestion assessed, only percent reduction in NT-proBNP was significantly associated with symptom relief ( r =0.13; P =0.04). There was no correlation between either weight loss or net fluid loss and symptom relief, ( r =0.04; P =0.54 and r =0.07; P =0.27, respectively). Favorable changes in each of the 3 markers of decongestion were associated with improvement in time to death, rehospitalization, or emergency department visit at 60 days (weight: hazard ratio, 0.91; 95% confidence interval, 0.85–0.97 per 4 lbs; weight lost; fluid hazard ratio, 0.94; 95% confidence interval, 0.90–0.99 per 1000 mL fluid loss; NT-proBNP hazard ratio, 0.95; 95% confidence interval, 0.91–0.99 per 10% reduction). These associations were unchanged after multivariable adjustment with the exception that percent reduction in NT-proBNP was no longer a significant predictor (hazard ratio, 0.97; 95% confidence interval, 0.93–1.02). The rates of death, HF hospitalization, or emergency department visit at 60 days for patients with 0, 1, 2, and 3 markers of decongestion (above the median) were 67%, 64%, 46%, and 38%, respectively (log rank P value=0.05). Figure. Relationship between number of markers of decongestion above median* and time to 60-day risk of emergency department (ED) visit, rehospitalization, or death. *Median net fluid loss, 3.8 L; median net weight loss, 6.5 lbs; median percent reduction in N terminal B-type natriuretic peptide 24.3%. Conclusions— Weight loss, fluid loss, and NT-proBNP reduction at 72 hours are poorly correlated with dyspnea relief. However, favorable improvements in each of the 3 markers were associated with improved clinical outcomes at 60 days. These data suggest the need for ongoing research to understand the relationships among symptom relief, congestion, and outcomes in patients with acute decompensated heart failure. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00577135.