April 13, 2005
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. |