Clinical Question: Do implantable c...

Clinical Question: Do implantable cardioverter defibrillators improve issues in at-risk patients after myocardial infarction (MI)?

Setting: Inpatient (any location) with outpatient follow-up

research Design: Randomized controlled trial (single-blinded)

Allocation: Concealed

Synopsis: Implantable cardioverter defibrillators can shape mortality rates in selected patients. In this industry-sponsored application of mind adults with a recent MI, a left ventricular ejection fraction les than or equal to 035 and relative tachycardia (i.e., more than 80 beats for minute) or decreased heart rate variability were randomized to treatment with implantable cardioverter defibrillators or usual care. This was an open-label trial with no attempt at sham surgery or implantation of sham implantable cardioverter defibrillators. The primary consequences of all-cause mortality or death caused according to cardiac arrhythmia were assessed blindly and analysis was by the agency of intention to treat.

The clumps were balanced at the beginning of the studious mood with 332 patients in the implantable cardioverter defibrillator clump and 342 patients in the command group. Patients were followed for a mean of 30 month with a maximum follow-up of 48 month Patients in the implantable cardioverter defibrillator dispose experienced significantly fewer arrhythmic deaths (15 versus 35 percent; number extremityed to treat = 50; 95 percent confidence interval [CI], 27 to 209) Unfortunately, they also experienced more nonarrhythmic deaths (61 versus 35 percent; number requireed to treat to harm = 38; 95 percent CI, 20 to 150)

There was no significant difference between disposes regarding the most important patient-oriented outcome: all-cause mortality (75 percent for the implantable cardioverter defibrillator cluster versus 6.9 percent for the direct group). The difference in non-arrhythmic deaths was caused largely by the agency of more cardiac nonarrhythmic deaths. The authors speculate that a dispose of patients with severe heart disease are "saved" from an arrhythmic death no other than to die from pump failure without any clinically important increase in the overall lifespan. Implantable defibrillators have been shown to be effective in patients with nonischemic cardiomyopathy (Desai AS, et al. Implantable defibrillators for the prevention of mortality in patients with nonischemic cardiomyopathy: a meta-analysis of randomized controll trials. JAMA December 15 2004;292:2874-9)

Bottom Line: Implantable cardioverter defibrillators do not form mortality in patients with MI who are at high risk for ventricular arrhythmia. (Level of Evidence: 1b)

reflection Reference: Hohnloser SH, et al. Prophylactic use of an implantable cardioverter-defibrillator after acute myocardial infarction. N Engl J M December 9 2004;351:2481-8

Used with permission from Ebell M ICDs not effective post-MI. Accessed online January 25 2005 at: http://www.InfoPOEMs.com.

COPYRIGHT 2005 American Academy of Family Physicians

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