Clinical features, myocardial strain and tissue characteristics of heart failure with preserved ejection fraction in patients with obesity: A prospective cohort study

BACKGROUND: The pathophysiology and subsequent myocardial dysfunction of heart failure with preserved ejection fraction (HFpEF) with comorbid obesity has not been extensively described. This study aimed to investigate the clinical features and cardiovascular magnetic resonance (CMR) derived myocardial strain and tissue characteristics in patients with HFpEF and comorbid obesity phenotype. METHODS: In this prospective cohort study, we included consecutive patients admitted to Fuwai hospital in China who underwent CMR. Patients with HFpEF or obesity were diagnosed with demographic data, clinical presentation, laboratory test, and echocardiography or CMR imaging. The key exclusion criteria were cardiomyopathy, primary valvular heart disease, and significant coronary artery disease. Participant data were obtained from the electronic medical records database or inquiry. Comparisons of clinical features and CMR derived structural and functional parameters amongst different groups were made using one-way analysis of variance, or χ(2) tests, and post hoc Bonferroni analysis where appropriate. FINDINGS: Between January 1, 2019 and July 31, 2021, 280 participants (108 patients with HFpEF and obesity, 50 patients with HFpEF and normal weight, 72 patients with obesity, and 50 healthy controls) were enrolled. Compared with patients with HFpEF and normal weight, patients with HFpEF and obesity were younger males, and had higher plasma volume, uric acid and hemoglobin levels, yet less often atrial fibrillation, and lower NT-proBNP levels, and had higher left ventricular mass index, end-diastole/systole volume index, lower left atrial volume index, and worse myocardial strains (all p ≤ 0.05), but no remarkable difference in late gadolinium enhancement (LGE) presence and extracellular volume fraction (ECV). After adjusting for age, atrial fibrillation, and coronary artery disease, only global longitudinal strain (GLS, p = 0.031) and early-diastolic global longitudinal strain rate (eGLSR, p = 0.043) were considerably worse in patients with HFpEF and obesity versus patients with HFpEF and normal weight. Furthermore, early-diastolic strain rates showed no linear association with ECV in patients with HFpEF and obesity. Moreover, GLS demonstrated the highest diagnostic ability when compared with traditional CMR structural parameters and ECV to diagnose patients with HFpEF and obesity in the setting of obesity. INTERPRETATION: Higher systemic inflammation, and worse GLS and eGLSR may be the distinct features of obesity-related HFpEF phenotype; strains and ECV may represent different mechanisms of HFpEF with obesity, deserving further study. FUNDING: The Construction Research Project of Key Laboratory (Cultivation) of Chinese Academy of Medical Sciences (2019PT310025); 10.13039/501100001809National Natural Science Foundation of China (81971588); Capital’s Funds for Health Improvement and Research (CFH 2020-2-4034); Youth Key Program of High-level Hospital Clinical Research (2022-GSP-QZ-5).