Background: Myocardial bridging is a common coronary anomaly, with few severe adverse events but a relevant symptom burden. Myocardial bridging treatment, however, remains uncertain because of the lack of randomized trials.
Material: MEDLINE/PubMed was systematically screened for studies reporting on isolated myocardial bridging diagnosed at coronary angiography or with coronary computed tomography in patients admitted for suspected angina or with an acute coronary syndrome. Baseline, treatment and outcome data were appraised and pooled according to treatment (medical therapy, bypass surgery/myotomy or stenting).
Results: A total of 899 patients in 18 studies were included with a low prevalence of traditional risk factors, especially diabetes (15.6%, interquartile range 2.5-21.5). After a median of 31.0 months (interquartile range 12.4-37.1), major cardiovascular events (composite of death, myocardial infarction or target vessel revascularization) occurred in only 3.4% of the study patients and 78.7% [70.5-86.9; 95% confidence intervals (CI)] were managed conservatively and free of symptoms. When an invasive strategy was planned, freedom from angina was higher in patients treated with surgery [84.5% (78.4-90.7; 95% CI)] than in those treated with stenting [54.7% (38.9-70.6; 95% CI)]. Patients in the stenting group experienced a high incidence of major cardiovascular events related to target vessel revascularization [40.07% (19.83-60.32; 95% CI)]. Meta-regression showed that patients treated with beta-blockers or with a history of hypertension were more likely to remain free from angina (B -0.6, P = 0.013; B -0.66, P = 0.006).
Conclusion: Patients with symptomatic isolated myocardial bridging generally have a good long-term prognosis. Pharmacological treatment alone, especially with beta-blockers, is able to improve angina in most cases. Surgical treatment appears to be more effective than stenting in nonresponders.