Secondary Prevention: The Ongoing Challenge

Abstract

Experts recommend the use of cardiac rehabilitation among patients with coronary disease.1 As hospital stays for acute coronary syndromes decrease, cardiac rehabilitation is assuming an increasingly important role in secondary prevention. There is a large amount of data indicating that cardiac rehabilitation improves several important intermediate end points, including exertional ischemic symptoms, depression and hostility scores, sense of wellness, understanding of the disease, and compliance with risk factor modification. With regard to survival, earlier randomized trials assessing the efficacy of cardiac rehabilitation after myocardial infarction have been limited by small sample size. When the results of individual trials were pooled, cardiac rehabilitation was associated with survival gains of 20% to 30%.2, 3 However, as these trials were conducted in the 1980s, it is uncertain that these data can be generalized to contemporary practice. The study by Brotons et al, published in this issue of Revista Espanola de Cardiologia 4 contributes to address this gap in knowledge by evaluating the efficacy of secondary prevention between 2004 and 2005. The authors report on 1224 patients with cardiovascular disease (coronary disease, cerebrovascular disease or peripheral arterial disease) from 42 practices in Spain, similarly distributed between control and intervention, the latter consisting of education and structured intervention based on the patient's risk factor profile. There was no benefit of the intervention on the primary endpoint (all-cause mortality and hospital readmissions) and marginal effects of questionable clinical significance on intermediate endpoints (risk factor profile), except for depression, which exhibited a notable difference between the 2 arms favoring intervention. These results underscore the importance of publishing “negative trials”, despite the prevalent study publication bias whereby statistically significant outcomes are more likely to be reported than non-significant outcomes.5 Indeed, the study generates several important questions.