The largest cohort study opens a new era for the management of heart failure in Japan.

eart failure is the common feature of the endstage for any type of cardiovascular disease (CVD) and is one of the most important causes of high morbidity and mortality in developed countries. This is also the situation in Japan, mainly because of rapid aging of the population, and increased survivors of serious CVD because of the recent advances in therapeutic strategies. Although it has been thought that both the prevalence and mortality of chronic heart failure (CHF) are relatively low in Japan, an early multicenter prospective cohort study (The Chronic Heart Failure Analysis and Registry in the Tohoku District 1 Study: CHART-1) clarified that the number of patients with HF in Japan was more than we thought, and that prognosis was as poor as that in Western countries.1,2 The most prevalent etiology of HF in the CHART-1 Study was nonischemic cardiomyopathy (28.6%), and coronary artery disease (CAD) accounted for only 25.4% of the total HF patients, which was considerably low compared with Western HF studies. On the other hand, Gheorghiade et al reported that admission for acute heart failure syndrome (AHFS) is a key event in the progression of CHF,3 which suggests that the process of CHF is largely modulated by the severity and frequency of AHFS, thus making the pathophysiology and prognosis of CHF varied. In fact, it is reported that hospitalized HF patients are a heterogeneous group with a wide range of 30-day mortality (1.7–7.2%) and a high postdischarge event rate, approaching 40% at 90 days.4 Since both the characteristics of such patients at high risk and the pathophysiology of the transition to decompensated HF from stable HF status remain uncertain, Shiba et al started a largescale multicenter prospective cohort study, named the Chronic Heart Failure Analysis and Registry in the Tohoku District 2 (CHART-2) Study, in which consecutive patients at high risk for progression of CVD or HF because of the development of AHFS were investigated.