Utilization and Efficacy of Cardiac Resynchronization Therapy in Patients With Chronic Heart Failure　― A Report From the CHART-2 Study ―

Background: Although cardiac resynchronization therapy (CRT) is effective for patients with chronic heart failure (CHF) with reduced left ventricular ejection fraction and wide QRS (≥120 ms), data on the use of or long-term outcomes after CRT implantation in Japan are limited. Methods and Results: We examined proper CRT utilization and outcomes in 3,447 consecutive symptomatic CHF patients registered in the CHART-2 Study. We identified 167 potentially eligible patients and divided them into 4 groups according to the presence (+) or absence (−) of an indication for and implantation of CRT: Group A (reference group), (+)indication/(+)CRT; Group B, (+)indication/(−)CRT; Group C, (−)indication/(+)CRT; and Group D, (−)indication/(−)CRT. Based on the Japanese Circulation Society guidelines, 91 patients met the eligibility for CRT implantation, with 43 (47%) of them undergoing CRT implantation. After adjusting for confounders, age was significantly associated with no CRT use (odds ratio per 5-year increase 1.46; 95% confidence interval 1.11–2.05; P=0.012). Among the 4 groups, the cumulative incidence of cardiovascular death and CHF admission were highest in Group B and lowest in Group D (P=0.029). Conclusions: In this study, only half the eligible CHF patients properly received CRT. Aging was a significant risk factor for no CRT use. Patients without CRT despite having an indication could be at higher risk of mortality and CHF admission.