Early intervention and long-term outcome with cardiac resynchronization therapy in patients without a history of advanced heart failure symptoms.

AIMS: MADIT-CRT showed that cardiac resynchronization therapy with a defibrillator (CRT-D) improves long-term outcomes in currently mildly symptomatic heart failure (HF) patients with LBBB regardless of the presence of prior advanced HF symptoms. We aimed to evaluate the long-term benefit of CRT-D in patients who never experienced advanced HF symptoms prior to device implantation.

METHODS AND RESULTS: Interaction term analysis was used to compare the clinical and echocardiographic benefit of CRT-D vs. implantable cardioverter defibrillator (ICD)-only therapy during long-term follow-up (median 5.6 years) between LBBB patients with or without a history of advanced HF [defined as NYHA class ≥ III or past hospitalization for worsening HF >3 months prior to enrolment in MADIT-CRT (n = 529 and 752, respectively)]. Multivariable analysis showed that treatment with CRT-D was associated with a significant reduction in the risk of HF or death during long-term follow-up regardless of the presence of prior advanced HF symptoms [hazard ratio 0.53 (P < 0.001) and 0.47 (P < 0.001) in the respective groups of patients with and without prior advanced HF; interaction P for the difference = 0.58]. Echocardiographic response to CRT at 1 year was also similar between the two groups (P > 0.10 for all comparisons).

CONCLUSION: Our findings suggest that treatment with CRT-D is associated with pronounced echocardiographic and long-term clinical benefit in patients with LV dysfunction and LBBB who never experienced advanced HF symptoms. These data further emphasize the benefit of early intervention with CRT in this population.