Introduction: Myocardial bridging with systolic compression (milking) of the left anterior descending coronary artery may be associated with myocardial ischemia. Little information is available about the long-term prognosis of patients with this coronary anomaly.
Material and methods: A review was made of coronary angiographies of patients diagnosed as ischemic heart disease made between 1994 and 1999 in two centers. The long-term follow-up of patients with myocardial bridging and systolic compression of the left anterior descending coronary artery was analyzed. Data were collected by reviewing medical records and completed by telephone interview.
Results: Prevalence: 0.72%. Milking was observed in 60 patients, but 25 of them were excluded due to associated hypertrophic cardiomyopathy, severe valvular disease, or coronary artery disease. The clinical follow-up was available for all patients (median: 43 months, range: 12-80 months). Mean age 55.7 years (SD = 11.9). Men 74%.
Clinical presentation: angina 26 patients, atypical chest pain with positive non-invasive test 8, acute myocardial infarction 1. During follow-up, 1 patient died of sudden cardiac death. Seven patients continued to present stable angina CCS class I-II, coronary angiography was repeated in 5 patients, and one required percutaneous revascularization for symptoms. In 63% of cases, antianginal drugs were still needed at the end of follow-up period (beta-blockers or calcium antagonists).
Conclusions: Patients with myocardial bridging and systolic compression of the left anterior descending artery have a good long-term prognosis, although more than half of them continue regular treatment with antianginal drugs. In a small percentage of cases percutaneous intervention must be performed and ischemic heart disease may appear in more aggressive forms (acute myocardial infarction or sudden death).