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Background
The pharmacologic treatment of patients with stable angina includes antianginal drugs to control symptoms and protective drugs to slow the progression of coronary artery disease (CAD) or to induce plaque stabilization.[1] However, mortality after a myocardial infarction (MI) continues to be high, with death due to a cardiovascular cause occurring in one in three patients within 2 years of the event.[2]
It is usual for antianginal drugs to be used for several months, and up to years, prior to an MI.[1] There are differences between antianginal drugs in their modes of action. β-Adrenoceptor antagonists (β-blockers) act primarily by decreasing myocardial oxygen consumption. Calcium channel antagonists dilate coronary and systemic arteries, increase coronary blood flow, and decrease myocardial oxygen consumption. Nitrates dilate systemic arteries, coronary arteries, systemic veins, and, by pooling of venous blood, decrease cardiac work and chamber size. The action of nicorandil is similar to nitrates; however, it may also enhance ischemic preconditioning. During ischemia, metabolic agents, such as trimetazidine, inhibit fatty acid oxidation and shift the metabolic process towards oxidative glycolysis, which is more efficient in generating energy. These differences in modes of action suggest that there may also be differences between antianginal drugs used in stable angina in terms of subsequent mortality.
β-Adrenoceptor antagonists have been shown to protect patients after an MI and patients with heart failure,[3] through a possible action that may involve prolonging the half-life of adenosine released by endothelial cells and myocytes.[4] However, few prospective studies[5,6] and a single meta-analysis[7] have examined the effects of antianginal drugs on mortality in patients with stable angina. In these studies, patients were receiving combination antianginal treatment, and the independent influence of individual agents on the outcome is unclear.
The Global Registry of Acute Coronary Events (GRACE) has made it possible to estimate the risk of death after surviving an MI.[8] The objective of our study was to use this as the outcome in a predictive multiple logistic regression model to assess the independent effects, on subsequent mortality risk, of different antianginal agents used in patients with stable angina prior to surviving an MI.
Methods
The METRO (ManagEment of angina: a reTRospective cOhort) study was conducted at five hospitals in Mumbai, Bangalore, Ahmedabad, Lucknow, and Calicut, India. Written informed consent...