Background: Because the effectiveness of strengthening guideline-based therapy (GBT) to prevent heart failure (HF) rehospitalization of chronic HF patients remains unclear, this study investigated the characteristics of HF patients in the Kobe University Heart Failure Registry in Awaji Medical Center (KUNIUMI) acute cohort. Methods and Results: We studied 254 rehospitalized HF patients from the KUNIUMI Registry. Optimized GBT was defined as a Class I or IIa recommendation for chronic HF based on the guidelines of the Japanese Circulation Society. The primary endpoint was all-cause death or first HF rehospitalization after discharge. Outcomes tended to be more favorable for patients who had rather than had not received optimized GBT (hazard ratio [HR] 0.82; 95% confidence interval [CI] 0.57-1.19; P=0.27). Similarly, among New York Heart Association (NYHA) Class IV patients, outcomes tended to be more favorable for those who had rather than had not undergone optimized GBT (HR 0.73; 95% CI 0.47-1.12; P=0.15). Importantly, outcomes were significantly more favorable among NYHA Class IV patients aged
