Diet and medication for heart protection in secondary prevention of coronary heart disease. New concepts

Abstract

Background: Sudden cardiac death (SCD) has accounted for about half of total cardiovascular mortality in recent secondary prevention trials. In addition, chronic heart failure (CHF) is becoming the first cause of hospitalisation of cardiac patients and rising to epidemic proportions in most Western countries. Strategies for the secondary prevention of coronary heart disease (CHD) and cardiac rehabilitation programmes should therefore primarily focus on the prevention of these two major clinical complications.

Objectives: To discuss the most effective medication and diet for the prevention of SCD in relation to the current emphasis on essentially two other major goals, namely prevention of thrombosis and modification of blood lipid parameters, and the effects of the Mediterranean type of diet in this context.

Data synopsis and conclusions: Experimental and clinical studies suggest that anti-platelet agents may have pro-arrhythmic effects and increase the risk of SCD. Warfarin should be thus preferred for patients at high risk of SCD (those with severe left ventricular dysfunction) and in its secondary prevention. Data from secondary prevention trials with statins have revealed differences in their specific effect on the end-point SCD. Simvastatin was significantly protective, whereas pravastatin was ineffective in both CARE and LIPID. The implication of this fact in the clinical practice might be substantial. Lastly, the most effective means of reducing the risk of SCD (apart from the prophylactic implantation of a defibrillator) appears to be dietary prevention in the light of animal experiments, epidemiological studies and four randomised trials showing that (n-3) fatty acids are extremely effective to prevent ischemic ventricular arrhythmias and SCD. However, in the two trials that assessed the actual effect of (n-3) fatty acids in the absence of other dietary changes, non-sudden cardiac death and non-fatal myocardial infarction were not reduced, suggesting that dietary changes in secondary prevention should be more global and not restricted to a single class of nutrient. Adoption of a dietary pattern, for instance a Mediterranean type of diet, seems to be the best way.