EMERGENCY CORONARY-ARTERY BYPASS-SURGERY FOLLOWING FAILED BALLOON ANGIOPLASTY - ROLE OF THE INTERNAL MAMMARY ARTERY GRAFT

During a 4-year period (1986-1989), 3,502 patients had percutaneous transluminal coronary angioplasty (PTCA) in our institution. One hundred nineteen (3.4%) patients required emergency coronary artery bypass graft surgery (CABG) because of abrupt vessel closure following PTCA. Factors associated with vessel closure included lesion angulation greater-than-or-equal-to 90-degrees (p < 0.007), the presence of thrombus (p < 0.02), or a long (greater-than-or-equal-to 2 cm) lesion (p < 0.03). Of these 119 emergency CABG patients, 108 (91%) arrived in the operating room in a stable condition (group I) and 11 (9%) were in cardiogenic shock (group II). Five (45%) of the group II patients were admitted to the hospital with an acute myocardial infarction and all 11 patients had a higher incidence of multivessel disease (p < 0.05) and lower left ventricular ejection fraction (p < 0.001) than group I patients. The overall surgical mortality was 10.1%; however, in group I the mortality was 5.6% and in group II it was 54.5% (p < 0.001). The vessel that abruptly closed ("culprit vessel") was the left anterior descending (LAD) in 60%, the right coronary artery in 27%, and the left circumflex in 13%. The internal mammary artery was utilized to bypass the culprit artery in 51 (43%) patients, including 50% of the culprit LADs. With group I culprit LAD patients, when the left IMA was the bypass conduit, there were no hospital deaths nor stokes and there was a 6.3% incidence of perioperative infarction.