Phenotyping cardiopulmonary exercise testing measures in heart failure with reduced ejection fraction: A comparison between Italy and Brazil

Background: While patients with heart failure (HF) with reduced left ventricular ejection fraction (HFrEF) constitutes a global health crisis the incidence, prevalence and prognosis of the disease may differ depending on the continent and country. Objective: To profile, analyze and compare cardiopulmonary exercise testing (CPET) data of patients with HFrEF between Italian and Brazilian cohorts. Methods: In this observational study, a total of 630 patients with clinical and functional diagnosis of HFrEF (315 patients from Brazil and 315 patients from Italy) performed CPET. Results: Although Brazilian patients were slightly younger (Brazil 60±10 vs Italy 64±11 p<0.001) with a better peak oxygen consumption (V̇O2), circulatory power and left ventricular ejection fraction (LVEF) (p<0.01), ventilatory inefficiency and oscillation ventilation was higher when compared to the Italian cohort. When stratifying patients with LVEF≤30 % and age≥60 years, Brazilian patients presented worse ventilatory efficiency, and lower peak V̇O2 compared to the Italian cohort. Conclusion: Patients with HFrEF from Brazil exhibited higher ventilatory inefficiency and a greater prevalence of oscillatory ventilation during CPET compared to patients with the same diagnosis from Italy.