Prognosis of patients with heart failure (HF) remains unclear in Japan and should be determined in a prospective fashion. A prospective cohort of The Shinken Database comprised details on all of the new patients, including both inpatients and outpatients, who visited The Cardiovascular Institute Hospital in 2004-2005. HF patients were defined as those with symptomatic HF coexisting with structural heart diseases. Among 4,255 patients who visited our hospital, 597 patients (male/female 414/183, age 65.1 +/- 12.9 years, LVEF 56.2 +/- 18.0%) were diagnosed as presenting symptomatic HF. Ischemic heart disease was present in 305 (51.1%), valvular heart disease in 212 (35.5%), dilated cardiomyopathy in 59 (9.9%), hypertrophic cardiomyopathy in 24 (4.0%), hypertensive heart disease in 14 (2.3%), and others in 67 (11.2%). Hypertension, atrial fibrillation, and diabetes were observed in 35.3%, 27.4%, and 23.7%, respectively. During the mean follow-up period of 539 +/- 257 days, 40 deaths (5.0% per year) occurred, including 34 cardiovascular deaths (4.5% per year, NYHA class II: 1.0%, III: 11.3%, IV: 36.6% per year, respectively). The present study showed that the prognosis of Japanese patients with HF among moderate to severe severity was found to be similar to that of Western countries. Multiple Cox hazard analysis identified the presence of chronic kidney disease and NYHA class as independent predictors for cardiovascular death. This prospective cohort study identified the prevalence, prognosis, and risk factors in HF patients to provide a basis for therapeutic management in Japan.