Rationale, design, and organization of the diastolic heart failure assessment study in Tohoku District (DIAST)

Abstract

Background: High mortality and a high readmission rate characterize diastolic heart failure (DHF), but evidence-based therapeutic strategies have not been established for DHF. Methods: The aim of a multicenter, randomized open trial (the Diastolic Heart Failure Assessment Study in Tohoku District, DIAST) is to evaluate the safety and prognostic efficacy of the multiple action non-selective β-blocker carvedilol in 160 patients with DHF (left-ventricular ejection fraction ≥50%). The target dose of carvedilol is 10mg twice a day and the mean follow-up is estimated to be 2 years. The primary endpoints are to evaluate (1) all-cause mortality or hospitalization, (2) cardiovascular mortality or hospitalization and (3) worsening heart failure. The secondary endpoints are to assess (1) cardiovascular events, (2) the individual components of the above combined endpoints, (3) the duration of hospitalization, (4) the functional class and exercise capacity and (5) the safety and tolerability. All patients' data are processed using an original registration system on an internet homepage. Several substudies to assess neurohumoral factors, heart rate variability, oxidative stress and sleep apnea will clarify the pathophysiology of DHF. Conclusions: The DIAST will contribute to establish therapeutic guidelines for DHF.