Effect of maximal medical therapy on refractoriness of unstable angina pectoris.

A group of 125 patients with unstable angina were studied over a 5-year period to define the incidence of refractory unstable angina in the current era of 5-drug medical therapy with intravenous heparin, aspirin, nitrates, calcium antagonists and beta blockers. All patients had greater than 20 minutes of chest pain at rest with reversible electrocardiographic changes occurring in the absence of myocardial infarction. Patients were considered refractory only if chest pain continued despite treatment with maximal 5-drug therapy. At the time of transfer to the center, 65 patients continued to have ischemic chest pain at rest and were considered "medically refractory" by their referring physicians. A more aggressive medical regimen was used, and 54 patients (83%) were rendered chest pain-free. Of the 11 truly refractory patients (8.8%), coronary arteriography revealed an increased likelihood of left main or 3-vessel disease (7 of 11 vs 26 of 114; p = 0.01). In-hospital treatment strategies for the 114 patients stabilized with medical therapy included continued medical therapy (n = 37), coronary angioplasty (n = 46) and bypass grafting (n = 31). The rate of myocardial infarction or death in patients managed medically was 3%. Coronary angioplasty in medically stabilized patients was complicated by an abrupt closure rate of 26%, and a 17% rate of myocardial infarction, death or need for emergency bypass grafting. Medically stabilized patients undergoing bypass grafting had a 9% rate of myocardial infarction or death. Unstable angina truly refractory to current, maximal medical therapy is infrequent (8.8%).(ABSTRACT TRUNCATED AT 250 WORDS)