Management of unstable coronary syndromes in patients with previous coronary artery bypass grafts following coronary angiography
Chan, A.W.; Ross, J.
Clinical and Investigative Medicine. Medecine Clinique et Experimentale 20(5): 320-326
1997
ISSN/ISBN: 0147-958X PMID: 9336657 Document Number: 482160
To characterize patients who had undergone previous coronary artery bypass grafting (CABG) and who were admitted for coronary angiography for unstable coronary syndromes, to determine the long-term therapy selected for these patients and to assess the outcomes of the intervention. Descriptive retrospective study. A university-affiliated tertiary care institution. A total of 129 patients with 1 previous CABG who underwent coronary angiography for myocardial infarction or unstable angina in 1991. Information regarding initial CABG, indications for cardiac angiography, cardiovascular risk factors, ultimate treatment selected and outcomes at 1 year were abstracted from patients' charts, and outcomes at 1 year were also determined by a patient survey. Seventy-six patients (59%) were given drug therapy, 28 patients (22%) were treated with angioplasty, and 25 (19%) underwent repeat surgery. During their index admissions, of patients given drug therapy, 4 (5.3%) died from myocardial infarction (MI) and 42 (55%) were discharged without complications; of those undergoing angioplasty, all except 2 were treated successfully (major procedural complications included nonfatal MI in 1 patient [4%] and nonfatal ventricular arrhythmia in 1 patient [4%], as well, reocclusion of the lesions occurred before discharge in 2 patients [7%]); of those undergoing repeat surgery, almost all patients (96%) were discharged, except 1 who died from MI during the postoperative period (there were no procedural complications, but early complications included nonfatal MI in 2 patients [8%], angina in 2 [8%] and nonfatal arrhythmias in 11 [44%]). Eighty-seven patients (67%) were available for follow-up at 1 year. Of the patients given drug therapy, 3 (6.4%) had died, 14 (30%) had recurrent anginal episodes and 5 (11%) required either angioplasty or CABG. Of the patients who initially received angioplasty, 15 (63%) had recurrent angina but none died, 12 (50%) underwent repeat angioplasty and 2 (8.3%) required repeat CABG. No patients who received repeat surgery died or required further surgery or angioplasty. Three of these patients (19%) had recurrent angina within the first year. Patients in this category also enjoyed a greater degree of symptomatic improvement of coronary artery disease. Patients who had a previous CABG and subsequently presented with MI were more likely to be given conservative drug therapy than those who presented with unstable angina. At 1-year follow-up, recurrent angina occurred more often in the patients treated by angioplasty, less often in patients given drug therapy and least in those who underwent repeat bypass grafting. Restenosis remained a problem, and about 50% of patients treated with angioplasty (without intracoronary stenting) required a second angioplasty within the first year. Patients who were candidates for repeat CABG enjoyed greater symptomatic improvement within the first year.