Information for Health Care Professionals

This page is presented here to provide more detailed information for physicians and other health care professionals who are interested in SCD-HeFT.

Background

Congestive heart failure is a common and lethal disease. A new diagnosis of congestive heart failure (CHF) is made in 400,000 Americans each year. Those with moderate left ventricular dysfunction have a substantial risk of premature death, approximately 25% over 2 1/2 years. Fifty percent of these deaths are thought to be sudden, due to arrhythmias, and may be preventable. As a consequence, CHF patients represent the largest single identifiable population of patients that can be targeted for primary prevention of sudden cardiac death (SCD).

Specific Aims

We have one primary clinical specific aim:

• To compare all cause mortality based on a minimum of 2.5 years of followup in the three arms of the study.

We have five secondary specific aims:

• To compare arrhythmic cardiac mortality in the three arms of the study.
• To compare non-arrhythmic cardiac mortality in the three arms of the study.
• To compare morbidity in the three arms of the study, defined as all-cause mortality and re-hospitalization for CHF.
• To compare health-related quality of life in the three arms of the study.
• To compare cost of care for each treatment group and calculate incremental cost-effectiveness ratios for the two intervention arms.

The principal clinical goal of this three arm, randomized, primary prevention trial is to identify therapy that will significantly reduce death rates in patients with CHF resulting from ischemic cardiomyopathy or nonischemic dilated cardiomyopathy. We will attempt to achieve this goal by reducing arrhythmic deaths in patients with CHF and a reduced ejection fraction (< 35%) and no record of sustained ventricular tachycardia (VT) or ventricular fibrillation (VF).

The principal economic and quality of life goals are to assess the consequences of the three treatments as measured by their cost-effectiveness and maintenance of physical, emotional, and social well-being.

The study will be a prospective, clinical trial with 2,500 patients randomly allocated in equal proportions to three different treatment arms over 2.5 years. The first arm of the study will be a control arm that consists of conventional heart failure therapy and placebo. Conventional CHF therapy will require the use of appropriate dose angiotensin converting enzyme (ACE) inhibitors. Hydralazine and nitrates, and especially losartan, have not been proven to be of similar value, and should only be used if the patient is absolutely intolerant to ACE inhibitors. Digoxin, diuretics, beta-blockers, warfarin and/or aspirin may be used at the discretion of the managing physician. The second arm of the study will combine conventional therapy, as defined above, with the use of amiodarone. In the first and second arms of the study, placebo and amiodarone will be delivered in a double-blind fashion. The third arm of the study will employ conventional therapy together with a single lead, pectoral ICD that will usually be inserted on an outpatient basis. Treatment arms will be compared using an intention-to-treat analysis.

By using readily available clinical measures of CHF and eliminating the need for specialized screening tests to identify subjects, the study is designed to facilitate ease of enrollment and to be broadly applicable as a primary prevention strategy implemented on an outpatient basis. The study will carry the acronym of SCD-HeFT, for Sudden Cardiac Death in Heart Failure Trial of prophylactic amiodarone or implantable defibrillator therapy v. placebo when combined with maximized heart failure therapy.

Study Design

We have intentionally excluded patients with NYHA Class I CHF due to their relatively symptom-free status. Similarly, we will not enroll Class IV patients in SCD-HeFT because of their limited prospects for long term survival. Although event rates are higher in this population, therapies directed toward sudden death are less likely to prolong life in these patients meaningfully. It is important to note that SCD victims do not represent the group of patients with end stage, Class IV CHF. Most SCD victims have been active and productive members of the community in the 55 to 65 year age range. Therefore, this study’s value lies with our target population of ambulatory patients with CHF where a focused intervention of modest-to-moderate cost will be more acceptable.

While the prevention of SCD is a major national public health goal, new therapies must not only produce evidence of efficacy, but also must show that any extra costs or incremental health benefits are produced in proportion to the incremental costs (i.e., they must be cost effective.) We propose to use state-of-the-art methods for measuring cost and quality of life for estimating cost effectiveness.

Conventional CHF Therapy Plus Drug (amiodarone/placebo)

Management of CHF must be maximized for enrollment in SCD-HeFT. The study requires a diagnosis of CHF for at least 3 months, with a minimum of 1 month maximized therapy utilizing ACE inhibitors. Nitrates and hydralazine, and especially losartan, have not been proven to be of similar value, and should only be used if the patient is absolutely intolerant to ACE inhibitors. The use of digoxin, diuretics, beta blockers, warfarin, and/or ASA is at the discretion of the managing physician.

Amiodarone or placebo will be delivered in a double-blind fashion.

Conventional CHF Therapy Plus ICD

The conventional therapy for CHF, as defined above, will add a single transvenous lead, pectoral ICD done on a less than 24 hours, short-stay basis, unless contraindicated by the patient’s condition.