Rationale, Design, and Methodology of the APOLLON trial: A comPrehensive, ObservationaL registry of heart faiLure with midrange and preserved ejectiON fraction

Abstract

Objective: Although almost half of chronic heart failure (HF) patients have mid-range (HFmrEF) and preserved left-ventricular ejection fraction(HFpEF), no studies have been carried out with these patients in our country. This study aims to determine the demographic characteristics andcurrent status of the clinical background of HFmrEF and HFpEF patients in a multicenter trial.Methods: A comPrehensive, ObservationaL registry of heart faiLure with mid-range and preserved ejectiON fraction (APOLLON) trial will bean observational, multicenter, and noninterventional study conducted in Turkey. The study population will include 1065 patients from 12 sites inTurkey. All data will be collected at one point in time and the current clinical practice will be evaluated (ClinicalTrials.gov number NCT03026114).Results: We will enroll all consecutive patients admitted to the cardiology clinics who were at least 18 years of age and had New York HeartAssociation class II, III, or IV HF, elevated brain natriuretic peptide levels within the last 30 days, and an left ventricular ejection fraction (LVEF)of at least 40%. Patients fulfilling the exclusion criteria will not be included in the study. Patients will be stratified into two categories accordingto LVEF: mid-range EF (HFmrEF, LVEF 40%-49%) and preserved EF (HFpEF, LVEF ?50%). Regional quota sampling will be performed to ensure thatthe sample was representative of the Turkish population. Demographic, lifestyle, medical, and therapeutic data will be collected by this specificsurvey.Conclusion: The APOLLON trial will be the largest and most comprehensive study in Turkey evaluating HF patients with a LVEF ?40% and will alsobe the first study to specifically analyze the recently designated HFmrEF category.