Sudden cardiac death primary prevention

Abstract Two thirds of the nearly half a million deaths per year in the United States due to sudden cardiac death (SCD) is attributed to coronary artery disease (CAD) and most commonly results from untreated ventricular tachyarrhythmias. Patients with ischemic cardiomyopathy and left ventricular dysfunction are at highest risk for SCD, but this still defines only a small subset of patients who will suffer SCD. Multiple lines of evidence now support the superiority of implantable cardioverter defibrillator (ICD) therapy over antiarrhythmic therapy for both primary and secondary prevention of SCD in advanced ischemic heart disease. Optimization of ICD therapy in advanced ischemic cardiomyopathy includes preventing right ventricular pacing as well as the use of highly effective anti-tachycardia pacing to reduce the number of shocks. While expensive, ICD therapy has been shown to compare favorably to the accepted standard of hemodialysis in cost effectiveness analyses. 

Evidence for Implantable Cardioverter Defibrillators for Primary Prevention of Sudden Cardiac Death... 

The results of MADIT II were met with some skepticism, but later confirmed by the recent Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) [24]. This study evaluated the benefit of ICD therapy versus amiodarone or placebo as primary prevention in over 2,500 patients with stable NYHA class II or III heart failure and EF < 35%, without the requirement for NSVT or EPS. Patients with both ischemic and nonischemic etiologies for cardiomyopathy were included. Over a follow-up of 4 years, there was no benefit of amiodarone over placebo for overall mortality, but ICD therapy resulted in a significant 23% reduction in overall mortality [p = 0.007] (Fig. 3.5). The benefit of ICD therapy was comparable for ischemic and nonischemic cardiomyopathy. 

The indications for implantation of an ICD have expanded considerably (Table 17-7). Initially, its efficacy was evaluated in patients who had already suffered a documented episode of ventricular tachycardia or ventricular fibrillation (secondary prevention), but now primary prevention trials have been published or are being planned. These results will help clinicians in choosing the proper therapy for patients with life-threatening arrhythmias. For instance, the Sudden Cardiac Death in Heart Failure Trial (SCD-Heft) is a primary prevention trial that evaluated survival in patients withLV dysfunction... 

In AFCAPS/TexCAPS, a primary prevention trial conducted in 6605 men and women aged 57 to 63 years with average total cholesterol and LDL concentrations (<221 mg/dL and <150 mg/dL, respectively) who were treated with lovastatin 20-40 mg/day for 5.2 years, a 37% reduction p <. 001) was shown in the risk for first acute major coronary event (fatal or nonfatal MI, unstable angina, or sudden cardiac death)." The need for revascularization procedures also was reduced by 33% p <. 001). The implications of this trial are enormous potentially millions of normal people could benefit... 

Kirchhof, R, G. Breithardt, and L. Eckardt, Primary prevention of sudden cardiac death. Heart, 2006. 92(12) p. 1873-8. 

Bansch, D., et al.. Primary prevention of sudden cardiac death in idiopathic dilated cardiomyopathy the Cardiomyopathy Trial (CAT). Circulation, 2002. 105(12) p. 1453-8. 

Uretsky, B.F. and R.G. Sheahan, Primary prevention of sudden cardiac death in heart failure will the solution be shocking J Am Coll Cardiol, 1997. 30(7) p. 1589-97. 

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