Clinical and angiographic outcomes after coronary artery stenting for acute or threatened closure after percutaneous transluminal coronary angioplasty. Initial results with a balloon-expandable, stainless steel design.

Abstract

Acute occlusion after balloon coronary angioplasty is associated with an increased risk of angina, emergency coronary artery bypass grafting (CABG), myocardial infarction (MI), and death. Stents offer a way of restoring patency and avoiding these complications. One hundred sixteen patients underwent attempted stent placement for imminent or total acute closure after PTCA. In 103 patients (110 stents, 105 procedures) the stent was successfully deployed (89%). Angiographic success (final diameter stenosis of < 50%) was achieved in 94 placements (85%). Seventy-one phase 2 procedures (CABG optional, n = 96; phase 1, CABG required, n = 9) were angiographically successful without complications of death, Q-wave myocardial infarction, or CABG (clinical success 74%). Stent placement was associated with resolution of ST-segment deviation and angina in 84% of patients. Five deaths and 5 Q-wave MIs occurred during hospitalization. Two deaths were related to pulmonary insufficiency from chronic lung disease and one patient died after rescue stent placement for left main coronary artery occlusion during routine angiography. Another patient died after CABG was followed by right ventricular MI. The last death occurred in an elderly patient who suffered a stroke while on intravenous heparin. During hospitalization nine patients developed reocclusion after stent placement (8.6% of procedures) and six had repeat PTCA. CABG was performed after 29 stent procedures (28%). The first nine patients underwent CABG as a mandate of the phase 1 protocol. In addition, nine patients had CABG after stenting with a good angiographic result but with a large amount of myocardium at risk. Clinical follow-up was obtained in all patients at a median of 14 months (range, 2 to 43). There were three late deaths (3%), two Q-wave myocardial infarctions (2%), 16 repeat PTCAs (16%), and 15 CABG procedures (15%). Angiographic restenosis (percent diameter > or = 50%) using caliper measurements was found in 30 of 57 patients (53%) at a median of 4 months (93% of patients eligible). A total of 41 procedures were successful and unaccompanied by death, emergency or elective coronary artery bypass grafting, or angiographic restenosis in follow-up. Restenosis and/or clinical events (death, MI, CABG, repeat PTCA) were associated with non-Q MI, hypertension, diabetes, left circumflex coronary artery stenting, saphenous vein graft stenting, smaller caliber artery stenting, higher balloon to artery ratios, and shorter inflation times. Coronary artery stenting for acute closure after PTCA relieves myocardial ischemia and provides an alternate means of treatment. This series includes early learning curve experience; 70% (67 of 96) of patients were spared emergency coronary artery bypass graft surgery when this adverse outcome occurred. Certain clinical and angiographic subsets are at increased risk for restenosis and future cardiac events.