Sudden cardiac death in heart failure trial

SCD-HeFT = Sudden Cardiac Death in Heart Failure Trial. 

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... 

Bardy GH, Lee KL, Mark DB, et al. Amiodarone or an Implantable Cardioverter-Defibrillator for Congestive Heart Failure. Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) Investigators. N Engl J Med 2005 352(3) 225—37. 

Gold MR, Ip JH, Costantini O, Poole JE, et al. Role of microvolt T-wave alternans in assessment of arrhythmia vulnerability among patients with heart failure and systolic dysfunction Primary results from the T-wave alternans Sudden Cardiac Death in Heart Failure Trial substudy. Circulation 2008 118 2022-8. 

In an SCD-HeFT (Sudden Cardiac Death Heart Failure Trial) substudy of MTWA, 490 patients were enrolled at 37 sites and followed for a mean of 35 months prospectively with a composite of primary endpoint of SCD, sustained ventricular arrhythmias, or an appropriate ICD discharge. This was a sick population of heart failure patients. MTWA was positive in 37%, negative in 22%, and indeterminate in 41%. There is no significant difference in survival between the MTWA positive and negative patients in the ICD and placebo arms. Mortality did not differ significantly between groups. These data indicate that MTWA results are frequently indeterminate and their ability to predict outcomes is limited. 

Several prospective randomized trials have reported that cilostazol improves walking distance in patients with intermittent claudication by 40 to 50%, compared to placebo after 12 to 24 weeks of treatment (20,21). One of these placebo-controlled trials evaluated both pentoxifylline and cilostazol (17). Pentoxifylline demonstrated no benefit in either onset of claudication or absolute claudication distance as compared to placebo. Cilostazol, however, significantly improved both distances compared to placebo (17). A prevalent side effect of cilostazol is headache. Transient diarrhea, palpitations, and dizziness have also been reported. The FDA has issued a warning regarding the use of cilostazol in patients with congestive heart failure, because of the increased possibility of sudden cardiac death observed with other forms of diesterase type III inhibitors. Thus, it has become routine practice to assess cardiac function clinically and echocardiographically prior to initiating therapy with cilostazol for claudication, and periodically thereafter. As a result of the modest vasodilatation, heart rate may increase by a mean of 5.1 and 7.4 beats per... 

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