Kingston-upon-Hull, UK- The Cardiac Resynchronization- Heart Failure (CARE-HF) was a multicenter, randomized trial comparing the effect of pharmacologic therapy alone and pharmacologic therapy with cardiac resynchronization in patients with left ventricular systolic dysfunction, cardiac dyssynchrony and symptomatic heart failure. This study by John Cleland M.D., et al from the Castle Hill Hospital in United Kingdom, was published in the April 14, 2005 issue of The New England Journal of Medicine. Their results indicated that in patients with heart failure and cardiac dyssynchrony, cardiac resynchronization improves symptoms and the quality of life.

Although pharmacologic treatment for heart failure has improved, the symptoms have not improved tremendously and the prognosis remains poor. Previous analyses have left uncertainty to the precise treatment of heart failure.

Patients with New York Association class III or IV heart failure due to left ventricular systolic dysfunction and cardiac dyssynchrony were randomly assigned to receive medical therapy alone or with cardiac resynchronization. Eligible patients had heart failure for at least 6 weeks, left ventricular ejection fraction of no more than 35 percent, a left ventricular end-diastolic dimension of at least 30 mm, and a QRS interval of at least 120 msec on the electrocardiogram. Patients with a QRS interval of 120 to 149 msec were required to meet two of three additional criteria for dyssynchrony: an aortic pre-ejection delay of more than 140 msec, an interventricular mechanical delay of more than 40 msec, or delayed activation of the posterolateral left ventricular wall. The primary end point was the time to death from any cause or a hospitalization for a cardiovascular event.

A total of 813 patients were enrolled and followed for a mean of 29.4 months. The primary end point was reached by 159 patients in the cardiac-resynchronization group, as compared with 224 patients in the medical-therapy group (39 percent vs. 55 percent; hazard ratio, 0.63; 95 percent confidence interval, 0.51 to 0.77; P<0.001). There were 82 deaths in the cardiac resynchronization group, as compared to 120 in the medical therapy group (20 percent vs. 30 percent; hazard ratio 0.64; 95 percent confidence interval 0.48 to 0.85; P<0.002). As compared to medical therapy alone, cardiac resynchronization reduced the risk of composite end point of death from any cause or hospitalization for worsening heart failure (95 percent confidence interval, 0.43 to 0.68; P<0.001). As compared to the medical-therapy group, patients in the cardiac-resynchronization group had less severe symptoms (P<0.001) and a better quality of life (P<0.001) at 90 days.

Ultimately, the study found that cardiac resynchronization significantly reduced the risk of complications and death among patients with moderate or severe heart failure owing to left ventricular systolic dysfunction and cardiac dyssynchrony.

Co-authors: Jean-Claude Daubert, M.D., Erland Erdmann, M.D., Nick Freemantle, Ph.D., Daniel Gras, M.D., Likas Kappenberger, M.D., and Luigi Tavazzi, M.D.