Outcomes of Cardiac Resynchronization Therapy With or Without Defibrillation in Patients With Nonischemic Cardiomyopathy

BACKGROUND:

Recent studies have cast doubt on the benefit of cardiac resynchronization therapy (CRT) with defibrillation (CRT-D) versus pacing (CRT-P) for patients with nonischemic cardiomyopathy (NICM). Left ventricular myocardial scar portends poor clinical outcomes.

OBJECTIVES:

The aim of this study was to determine whether CRT-D is superior to CRT-P in patients with NICM either with (+) or without (-) left ventricular midwall fibrosis (MWF), detected by cardiac magnetic resonance.

METHODS:

Clinical events were quantified in patients with NICM who were +MWF (n = 68) or -MWF (n = 184) who underwent cardiacmagnetic resonance prior to CRT device implantation.

RESULTS:

In the total study population, +MWF emerged as an independent predictor of total mortality (adjusted hazard ratio [aHR]: 2.31; 95% confidence interval [CI]: 1.45 to 3.68), total mortality or heart failure hospitalization (aHR: 2.02; 95% CI: 1.32 to 3.09), total mortality or hospitalization for major adverse cardiac events (aHR: 2.02; 95% CI: 1.32 to 3.07), death from pump failure (aHR: 1.95; 95% CI: 1.11 to 3.41), and sudden cardiac death (aHR: 3.75; 95% CI: 1.26 to 11.2) over a maximum follow-up period of 14 years (median 3.8 years [interquartile range: 2.0 to 6.1 years] for +MWF and 4.6 years [interquartile range: 2.4 to 8.3 years] for -MWF). In separate analyses of +MWF and -MWF, total mortality (aHR: 0.23; 95% CI: 0.07 to 0.75), total mortality or heart failure hospitalization (aHR: 0.32; 95% CI: 0.12 to 0.82), and total mortality or hospitalization for major adverse cardiac events (aHR: 0.30; 95% CI: 0.12 to 0.78) were lower after CRT-D than after CRT-P in +MWF but not in -MWF.

CONCLUSIONS:

In patients with NICM, CRT-D was superior to CRT-P in +MWF but not -MWF. These findings have implications for the choice of device therapy in patients with NICM.

PMID: 28859784

Posted in Magnetic Resonance Imaging and tagged , , , , .

One Comment

  1. Editorial comment:
    Selecting Patients With Nonischemic Dilated Cardiomyopathy for ICDs: Myocardial Function, Fibrosis, and What’s Attached?
    Cleland, J. G. F., Halliday, B. P., et al
    [link]

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