Isolated myocardial bridges with angiographic milking of the left anterior descending coronary artery: a long-term follow-up study.

Among 7467 consecutive coronary angiograms performed during an 8-year period, 61 patients had a myocardial bridge of the left anterior descending coronary artery. The overall prevalence of myocardial bridges was 0.82% (from 0.41% to 1.16% per year). Among these patients, 26 had coronary artery disease, 4 had valvular heart disease, and 3 had cardiomyopathy. We studied the long-term outcome (11 +/- 3 years) of the other 28 patients with isolated milking at baseline. Two groups were constituted according to the percentage of systolic reduction of the left anterior descending coronary artery lumen: group A, < 50% (15 patients) and group B, > or = 50% (13 patients). During follow-up, 1 group A patient (cancer) and 2 group B patients (1 cancer and 1 suicide) died. Moreover, 1 group B patient was lost to follow-up. None of the patients sustained a myocardial infarction during follow-up. In group A patients, 71% felt very well or well and 50% had clinical symptoms; 64% took antianginal medications. In group B patients, 50% felt well and 70% had clinical symptoms; 50% took antianginal drugs. The long-term prognosis of isolated myocardial bridges of the left anterior descending coronary artery is good and is independent of the severity of systolic narrowing of internal lumen diameter.