Current status of cardiac resynchronization therapy with defibrillators and factors influencing its prognosis in Japan

PurposeThe purpose of this study was to clarify the prognosis of cardiac resynchronization therapy with defibrillators (CRT-Ds) in Japan.MethodsWe selected 384 patients implanted with a CRT-D device from the observation database (n=1482) of the Japanese Cardiac Device Therapy Registry. We investigated the CRT criteria, including the presence of New York Heart Association (NYHA) class III/IV symptoms, left ventricular ejection fraction (LVEF) ≤35%, and QRS duration ≥120 ms. The patients were divided into 2 groups: the group fulfilling all of the 3 criteria (Group A, n=229) and the group not fulfilling the criteria (Group B, n=155). We compared mortality and appropriate shock rates between the 2 groups.ResultsThere was no significant difference in mortality (17.9% vs. 13.5%) or appropriate shock rates (32.5% vs. 31.6%) during the observation period of 29.0±15.7 months between the 2 groups. A logistic multivariate analysis showed that appropriate shocks (hazard ratio [HR]=1.85) and class III antiarrhythmic agents (HR=2.33) were independently associated with all-cause death, and that age ≥70 years (HR=0.55), male gender (HR=2.07), and presence of a single-chamber device (HR=1.78) were associated with appropriate shocks. The prognosis of Group A was better than that of the COMPANION trial.ConclusionsJapanese patients with CRT-D devices had a better prognosis than did those in the COMPANION trial, but no significant differences were observed between patients fulfilling and those not fulfilling the above mentioned criteria.