Rationale and Protocol of the Registry for Contemporary Medical Management of Chronic Heart Failure With Mildly Reduced and Preserved Ejection Fraction　- The PARACLETE Study.

Background: There is recent evidence for the medical treatment of heart failure (HF) with mildly reduced ejection fraction (EF) and preserved EF (HFmrEF/HFpEF). However, in real-world settings, information on how cardiologists treat patients with HFmrEF/HFpEF, especially those with chronic, mild, and stable HF or newly diagnosed HF, is lacking. In other words, we do not know when cardiologists should start and intensify medical treatment, which drugs they should choose, or why. To answer these questions, we will conduct an observational study of HFmrEF/HFpEF. Here, we describe the rationale and protocol of this observational study. Methods and Results: This study will explore the therapeutic status of approximately 4,200 patients who were diagnosed or newly diagnosed with chronic HFmrEF/HFpEF (LVEF >40%) at approximately 70 cardiology clinics and hospitals. After enrolment, physicians will check whether the current medical therapy is appropriate for each patient and initiate or intensify HF medical therapy appropriately. The primary endpoints will be: (1) the proportion of patients within the categories of reasons for changing prescriptions at visit 1 of HF medical therapy and (2) a composite of unexpected HF hospitalization and all-cause death in a 2-year follow-up. Conclusions: This registry will uniquely confirm the current treatment status of patients with HFmrEF/HFpEF in real-world settings.