Long term angiographic and clinical follow up in patients with stent implantation for symptomatic myocardial bridging

Objective-To assess long term results of coronary stent implantation in pat ients with symptomatic myocardial bridging. Methods-Intracoronary stent implantation was performed within the intramura l course of the left anterior descending coronary artery in 11 patients wit h objective signs of myocardial ischaemia and absence of other cardiac diso rders. All had myocardial bridging of the central portion of the left anter ior descending coronary artery. Quantitative coronary angiography was perfo rmed before and after stent deployment, and again at seven weeks and six mo nths. Clinical evaluation was done at two years. Results-After stent deployment, quantitative coronary angiography showed ab sence of systolic compression along the left anterior descending coronary a rtery; the minimum luminal diameter (mean (SD)) increased from 0.6 (0.3) mm before stent implantation to 1.9 (0.3) mm after implantation (p < 0.05). I ntravascular ultrasound showed an increase in cross sectional area from 3.3 (1.3) mm(2) at baseline to 6.8 (0.9) mm(2) (p < 0.005) after stent deploym ent. Coronary flow reserve was normalised from 2.6 (0.5) at baseline to 4.0 (0.5) (p < 0.005) after stent implantation. At seven weeks, quantitative c oronary angiography showed mild to moderate or severe in-stent stenosis in five of the 11 patients; four of these underwent repeat target vessel revas cularisation (percutaneous transluminal coronary angioplasty in two; corona ry artery bypass grafting in two). At six months, all patients (n = 9) show ed good angiographic results, including those who had target vessel revascu larisation. On clinical evaluation at two years, all patients (including th ose with target vessel revascularisation) remained free of angina and cardi ac events. Conclusions-Intracoronary stent implantation prevents external compression of bridged coronary artery segments, with increase in luminal diameter and alleviation of symptoms. The incidence of in-stent stenosis requiring targe t vessel revascularisation (36%) is comparable with that of lesions of 25 m m length in coronary artery disease. The symptom free and event free two ye ar follow up data suggest that stent implantation is a useful way of treati ng symptomatic patients with myocardial bridges.