Evidence-Based Application of Natriuretic Peptides in the Evaluation of Chronic Heart Failure With Preserved Ejection Fraction in the Ambulatory Outpatient Setting
BACKGROUND: Plasma NT-proBNP (N-terminal pro-B-type natriuretic peptide) is commonly used to diagnose heart failure with preserved ejection fraction (HFpEF), but its diagnostic performance in the ambulatory/outpatient setting is unknown because previous studies lacked objective reference standards. METHODS: Among patients with chronic dyspnea, diagnosis of HFpEF or noncardiac dyspnea was determined conclusively by exercise catheterization in a derivation cohort (n=414), multicenter validation cohort 1 (n=560), validation cohort 2 (n=207), and a nonobese Japanese validation cohort 3 (n=77). Optimal NT-proBNP cut points for HFpEF rule out (optimizing sensitivity) and rule in (optimizing specificity) were derived and tested, stratified by obesity and atrial fibrillation. Derived cut points were tested in 3 additional validation cohorts (cohorts 4–6) in whom HFpEF was diagnosed by resting catheterization only (n=260), previous hospitalization for heart failure (n=447), or exercise echocardiography (n=517), respectively. RESULTS: Current recommended rule-out NT-proBNP threshold <125 pg/mL had 82% sensitivity (95% CI, 77%–88%) with a body mass index (BMI) <35 kg/m 2 , decreasing to 67% (95% CI, 58%–77%) with a BMI ≥35 kg/m 2 . A lower rule-out NT-proBNP threshold <50 pg/mL displayed good sensitivity with a BMI <35 kg/m 2 (97% [95% CI, 95%–99%]), with a modest decline in sensitivity with a BMI ≥35 kg/m 2 (86% [95% CI, 79%–93%]); diagnostic thresholds were confirmed in validation cohorts 1 and 2 (91% [95% CI, 88%–95%] and 86% [95% CI, 80%–93%] with a BMI <35 kg/m 2 ; 80% [95% CI, 74%–87%] and 84% [95% CI, 74%–93%] with a BMI ≥35 kg/m 2 ). Current consensus age- and BMI-stratified rule-in thresholds demonstrated only 65% specificity (95% CI, 57%–72%). Rule-in NT-proBNP threshold ≥500 pg/mL had 85% specificity (95% CI, 78%–91%) with a BMI <35 kg/m 2 (87% [95% CI, 80%–94%] and 90% [95% CI, 81%–99%] in validation cohorts), with 100% specificity at a BMI ≥35 kg/m 2 (93% [95% CI, 81%–100%] and 100% in validation cohorts). With a BMI ≥35 kg/m 2 , lower rule-in thresholds (≥220 pg/mL) provided good specificity (88% [95% CI, 73%–100%]; 93% [95% CI, 81%–100%] and 100% in validation cohorts). Findings were consistent in validation cohorts 3 through 6 (sensitivity of <50 pg/mL, 93%–98%; specificity of ≥500 pg/mL, 82%–89%). NT-proBNP provided no incremental discrimination among patients with history of AF; ≥98% of patients with AF and dyspnea were found to have HFpEF in our cohorts. CONCLUSIONS: In patients with chronic unexplained dyspnea, current rule-in and rule-out NT-proBNP diagnostic thresholds lead to unacceptably high error rates, with important interactions by obesity and AF status. In our study, NT-proBNP provided little value in those with AF and dyspnea because the presence of AF is by itself a robust biomarker of HFpEF. Use of separate rule-in and rule-out diagnostic thresholds stratified by BMI reduces miscategorization and can guide more appropriate use of exercise testing for possible HFpEF.
Single-Leg Supine Cycling: An alternative for Patients Requiring Exercise Catheterization and Femoral Access
Abstract Aims Pulmonary regurgitation (PR) after reparative intervention for congenital heart disease has been studied extensively. However, the burden, distribution of causes, and outcome of PR in adults is unknown. The study aimed to evaluate the prevalence, types, and outcomes of moderate/severe PR in adults in the community setting. Methods and results A total of 398 adult residents of Olmsted County who had clinically indicated echocardiography 2004–2023 at Mayo Clinic, Rochester, and had moderate or severe PR were identified retrospectively. The median age was 77 years, 48% were females, and 61 (51%) had severe PR. The age- and sex-adjusted US prevalence was 0.11% (vs. 0.67% for ≥moderate tricuspid regurgitation). Moderate/severe PR was due to pulmonary hypertension in 77%, congenital/iatrogenic in 11%, primary pulmonary valve disease in 2% (88% due to carcinoid), and idiopathic isolated in 10%. In contrast, severe PR was due to congenital/iatrogenic disease in 52%, pulmonary hypertension in 39%, primary PR in 5%, and isolated idiopathic in 3%. The all-cause mortality rate per 100 person-year was 73 in primary (mostly carcinoid) PR, 16 in pulmonary hypertension–related PR (not different vs. propensity-matched patients without PR), and 6 in isolated idiopathic PR (not different vs. matched patients without PR). Conclusion Moderate or severe PR had a lower prevalence vs. TR. The most frequent cause was pulmonary hypertension for ≥moderate PR and congenital/iatrogenic for severe PR. Mortality in patients with acquired ≥moderate PR appeared to be related to the underlying cause, with no excess mortality compared with matched patients without PR. Whether specifically severe PR confers excess mortality requires future investigation.
Baseline Kidney Function and the Effects of Dapagliflozin On Health Status in Heart Failure in DEFINE-HF and PRESERVED-HF
Abstract Aims Sodium–glucose co-transporter-2 (SGLT2) inhibitors improve health status and outcomes in the setting of heart failure (HF) across the range of ejection fraction (EF). Baseline kidney disease is common in HF, complicates HF management and is strongly linked to worse health status. This study aimed to assess whether the treatment effects of dapagliflozin on health status vary based on estimated glomerular filtration rate (eGFR). Methods and Results We conducted a pooled participant-level analysis of two double-blind, randomized trials, DEFINE-HF (n = 236) and PRESERVED-HF (n = 324), which evaluated dapagliflozin versus placebo. Both multicentre studies enrolled adults with HF, New York Heart Association Class II or higher, elevated natriuretic peptides, and an EF < 40% in DEFINE-HF or >45% in PRESERVED-HF. The primary exposure was eGFR. The main outcome was the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) at 12 weeks. Across both trials, there were 583 (99.3%) participants with a baseline eGFR. The median (25th, 75th) eGFR was 59 (46, 77) mL/min/1.73 m2. Dapagliflozin improved KCCQ-CSS at 12 weeks [placebo-adjusted difference, +5.0 points, 95% confidence interval (CI) 2.6–7.5; P < 0.001], and this was consistent in participants with an eGFR ≥ 60 (+6.0 points, 95% CI 2.4–9.7; P = 0.001) and eGFR < 60 (+4.1 points, 95% CI 0.5–7.7; P = 0.025) (P interaction = 0.46). The benefits of dapagliflozin on KCCQ-CSS remained robust across eGFR when modelled as a continuous variable (P interaction = 0.48). Conclusions Dapagliflozin led to early and clinically meaningful improvements in health status in HF patients, regardless of EF or baseline eGFR.
Alterations in Mitochondrial Function in Pulmonary Vascular Diseases
Aims: Alterations of mitochondrial bioenergetics and arginine metabolism are universally present and mechanistically linked to pulmonary arterial hypertension (PAH), but there is little knowledge of arginine metabolism and mitochondrial functions across the different pulmonary hypertension (PH) groups. We hypothesize that abnormalities in mitochondrial functions are present across all PH groups and associated with clinical phenotypes. We test the hypothesis in PH patients and healthy controls from the Pulmonary Vascular Disease Phenomics Program cohort, who had comprehensive clinical phenotyping and follow-up for at least 4 years for death or transplant status. Mitochondrial transmembrane potential, superoxide production, and mass were measured by flow cytometry in fresh platelets. Metabolomics analysis was performed on plasma samples. Global arginine bioavailability was calculated as the ratio of arginine/(ornithine+citrulline). Results: Global arginine bioavailability is consistently lower than controls in all PH groups. Although the mitochondrial mass is similar across all PH groups and controls, superoxide production and transmembrane potential vary across groups. Mitochondrial superoxide is higher in group 1 PAH and lowest in group 3 compared with other groups, while transmembrane potential is lower in group 1 PAH than controls or group 3. The alterations in mitochondrial functions of group 1 PAH are associated with changes in fatty acid metabolism. Mitochondrial transmembrane potential in group 1 PAH is associated with transplant-free survival. Conclusion: While alterations in mitochondrial function are found in all PH groups, group 1 PAH has a unique mitochondrial phenotype with greater superoxide and lower transmembrane potential linked to fatty acid metabolism, and clinically to survival. Antioxid. Redox Signal. 42, 361–377.
Aerobic Capacity of Adults With Fontan Palliation: Disease-Specific Reference Values and Relationship to Outcomes
BACKGROUND: Patients with Fontan palliation have reduced aerobic capacity because of impaired cardiac, pulmonary, and skeletal muscle function. However, the assessment of aerobic capacity in this population still relies on comparisons with people without cardiovascular disease rather than comparison with the expected aerobic capacity of other Fontan patients. The purpose of this study was to determine the expected aerobic capacity of adults with Fontan palliation. METHODS: Adults with Fontan palliation who underwent a cardiopulmonary exercise test at Mayo Clinic (2003–2023) were stratified into quartiles based on the predicted peak oxygen consumption (VO 2 ). We assessed the correlates of predicted peak VO 2 and the relationship between predicted peak VO 2 quartiles and cardiovascular outcomes (death/transplant). RESULTS: Of 323 patients (age, 29±9 years; 177 [55%] men), the median peak VO 2 was 19.1 (15.2–23.9) mL/kg per minute, and this corresponds to a predicted peak VO 2 of 51% (range, 19–88; interquartile range, 41–62). After multivariable adjustments, the correlates of predicted peak VO 2 were body mass index (β±SE, −2.61±0.95; 2.61% decrease in predicted peak VO 2 per 5 kg/m 2 increase in body mass index; P =0.009), systemic saturation (β±SE, 3.65±0.85; 3.65% increase in predicted peak VO 2 per 5% increase in oxygen saturation; P <0.001), and Fontan pressure (β±SE, −1.24±0.22; 1.24% decrease in predicted peak VO 2 per 1 mm Hg increase in Fontan pressures; P <0.001). There was a 47% increase in the risk for death/transplant from a higher predicted peak VO 2 quartile to the next lower quartile (adjusted hazard ratio, 1.47 [95% CI, 1.09–2.05]; P =0.01). CONCLUSIONS: The results of the current study would help calibrate the interpretation of exercise test data in adults with Fontan palliation and improve risk stratification in this population. It also underscores the need to maintain normal Fontan hemodynamics and body weight, which are important determinants of aerobic capacity.
Association Between Locomotor Muscle Quality and Cardiac Function During Exercise in Heart Failure with Preserved Ejection Fraction
BACKGROUND: Patients with heart failure with preserved ejection fraction and obesity have significant disability and frequent exacerbations of heart failure. We hypothesized that tirzepatide, a long-acting agonist of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors, would improve a comprehensive suite of clinical end points, including measures of health status, functional capacity, quality of life, exercise tolerance, patient well-being, and medication burden, in these patients. METHODS: We randomized (double-blind) 731 patients with class II to IV heart failure, ejection fraction ≥50%, and body mass index ≥30 kg/m 2 to tirzepatide (titrated up to 15 mg SC weekly; n=364) or placebo (n=367) added to background therapy for a median of 104 weeks (quartile 1, 66; quartile 3, 126 weeks). The primary end points were whether tirzepatide reduced the combined risk of cardiovascular death or worsening heart failure and improved Kansas City Cardiomyopathy Questionnaire Clinical Summary Score. The current expanded analysis included sensitivity analyses of the primary end points, 6-minute walk distance, EQ-5D-5L health state index, Patient Global Impression of Severity Overall Health score, New York Heart Association class, use of heart failure medications, and a hierarchical composite based on all-cause death, worsening heart failure, and 52-week changes in Kansas City Cardiomyopathy Questionnaire Clinical Summary Score and 6-minute walk distance. RESULTS: Patients were 65.2±10.7 years of age; 53.8% (n=393) were female; body mass index was 38.2±6.7 kg/m 2 ; Kansas City Cardiomyopathy Questionnaire Clinical Summary Score was 53.5±18.5; 6-minute walk distance was 302.8±81.7 m; and 53% (n=388) had a worsening heart failure event in the previous 12 months. Compared with placebo, tirzepatide produced a consistent beneficial effect across all composites of death and worsening heart failure events, analyzed as time to first event (hazard ratios, 0.41–0.67). At 52 weeks, tirzepatide increased the Kansas City Cardiomyopathy Questionnaire Clinical Summary Score by 6.9 points (95% CI, 3.3–10.6; P <0.001), 6-minute walk distance 18.3 meters (95% CI, 9.9–26.7; P <0.001), and EQ-5D-5L 0.06 (95% CI, 0.03–0.09; P <0.001). The tirzepatide group shifted to a more favorable Patient Global Impression of Severity Overall Health score (proportional odds ratio, 1.99 [95% CI, 1.44–2.76]) and New York Heart Association class (proportional odds ratio, 2.26 [95% CI, 1.54–3.31]; both P <0.001) and required fewer heart failure medications ( P =0.015). The broad spectrum of effects was reflected in benefits on the hierarchical composite (win ratio, 1.63 [95% CI, 1.17–2.28]; P =0.004). CONCLUSIONS: Tirzepatide produced a comprehensive, meaningful improvement in heart failure across multiple complementary domains; enhanced health status, quality of life, functional capacity, exercise tolerance, and well-being; and reduced symptoms and medication burden in patients with heart failure with preserved ejection fraction and obesity. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04847557.
Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity