CRT durability showcased in CARE-HF long-term analysis

The significant survival gains from cardiac resynchronization therapy (CRT) seen within the first year or two of Cardiac Resynchronization in Heart Failure (CARE-HF), one of the seminal randomized trials that established the heart-failure device therapy as mainstream, persisted for seven years or more, according to a long-term follow-up of the trial, one of the longest of its kind.

Nearly all of those originally assigned to the trial's no-CRT control group ultimately received CRT after about three years, and although their survival thereafter improved, it didn't catch up with the survival of those who received CRT in the first place, reported Dr John GF Cleland (University of Hull, Kingston-upon-Hull, UK) when presenting the CARE-HF long-term analysis at the European Society of Cardiology 2010 Congress.

He said that the findings "suggest that the benefits of CRT observed in the main [CARE-HF] trial are preserved during the long-term follow-up." Median survival of CRT recipients aged 65 or younger in the trial exceeded seven years, he said, and their survival consistently surpassed those originally assigned to the control group regardless of their age at enrollment.

CARE-HF randomized 813 patients in NYHA class 3-4 HF despite standard drug therapy, an LVEF <35%, and a QRS duration of >120 ms (anyone with a QRS <150 ms also needed to have echocardiographic confirmation of ventricular dyssynchrony) to receive either continued medical therapy (n=404) or to be implanted with a pacing-only CRT device (CRT-P) (n=409).

Over a mean of almost 30 months, CRT was associated with a 37% drop in risk of the primary end point, all-cause mortality or an unplanned CV hospitalization (p<0.0001), and a 36% decrease in all-cause mortality (p=0.0019). The CRT group showed significant improvement in LVEF, NYHA class, end-systolic volume, mitral-valve function, blood pressure, quality-of-life indices, and—rarely studied in the major CRT trials—natriuretic peptide levels.