The relative risk of myocardial infarction in patients who have high blood pressure and non-cardiac pain.

The authors conducted a population-based case--control study to determine the risk of myocardial infarction in patients who reported angina-like symptoms. The cases studied were those of patients who had high blood pressure and had sought treatment in 1984 with myocardial infarction as the first manifestation of coronary artery disease. Controls, a random sample of patients who had hypertension, were frequency-matched to cases by age and gender. Blind to case--control status, the authors reviewed the medical records of the 32 cases and 64 controls for reports of angina-like symptoms. While controls reported such symptoms at a constant rate, the events for the cases clustered near their infarctions. When a patient with hypertension sought medical advice for angina-like symptoms, the risk of infarction within 30 days was 14.2 (95% confidence interval, 2.8 to 71), and after 30 days it fell to 1.03. Among patients who have high blood pressure but no history of angina, presentations with prodromal symptoms in the primary care setting are so common that only about one in 100 such visits actually heralds myocardial infarction.