Implantable Defibrillator Improves Survival with Time
Survival benefit seen more than six months after revascularization
THURSDAY, May 11 (HealthDay News) -- An implantable cardioverter-defibrillator (ICD) improves survival in high-risk cardiac patients, but only when the device is implanted more than six months after a revascularization procedure, according to a study in the May 2 issue of the Journal of the American College of Cardiology.
Ilan Goldenberg, M.D., from the University of Rochester Medical Center in Rochester, N.Y., and colleagues analyzed data on 951 patients with prior myocardial infarction and a left ventricular ejection fraction of 30 percent or less. After undergoing a revascularization procedure, 580 patients had received an ICD while the remaining 371 had received conventional therapy.
The researchers found that there was a survival benefit in patients receiving an ICD, although this was only observed in patients enrolled more than six months after revascularization (hazard ratio 0.64). The risk of death increased significantly with time in patients receiving conventional therapy, which was mostly attributed to patients enrolled more than six months after revascularization.
"In patients with ischemic left ventricular dysfunction, the efficacy of ICD therapy after coronary revascularization is time dependent, with a significant life-saving benefit in patients receiving device implantation more than six months after coronary revascularization," Goldenberg and colleagues conclude. "The lack of ICD benefit when implanted early after coronary revascularization may be related to a relatively low risk of sudden cardiac death during this time period."