PTCA Follow-up clinical results in patients undergoing percutaneous transluminal coronary angioplasty

Complete follow-up data were obtained from 229 consecutive patients who underwent percutaneous transluminal coronary angioplasty (PTCA) between 1979 and 1982 (mean follow-up 14 months, range 6 to 37). Single-vessel disease was present in 143 and multivessel disease in 86. PTCA was successful in 153 patients (67%). Failure was followed initially by bypass surgery in 59 and by continued medical therapy in 17. After successful PTCA, 90% of patients were improved subjectively and 74% were asymptomatic at follow-up. After unsuccessful PTCA but prompt bypass, 90% were improved subjectively and 85% were asymptomatic. Among the 229 patients, 39 (17%) required an additional intervention because of angina during follow-up; 15 of these had repeat PTCA and 18 had bypass surgery. Among patients with successful PTCA, revascularization was complete in 77% and partial in 23%. The completeness of revascularization with PTCA had a significant impact on followup. The follow-up data of patients with successful single-vessel PTCA and of those with multivessel disease with complete revascularization were similar. When the patients with complete revascularization were compared with those with multivessel disease but incomplete revascularization, the followup data were characterized by a higher incidence of angina or need for bypass surgery in the latter group (63%) than in the former group (29%); those with incomplete revascularization also had a significantly reduced event-free survival. Circulation 71, No. 4, 754-760, 1985. PERCUTANEOUS TRANSLUMINAL coronary angioplasty (PTCA) has rapidly become an established therapeutic option for selected patients with coronary artery disease. '-" It is of proven efficacy both for the relief of symptoms and for the improvement of myocardial function.5 7 8.12 Despite growing acceptance, several problems remain, including the need to document its long-term efficacy. Although the National Heart, Lung, and Blood Institute (NHLBI) PTCA Registry provides information on the follow-up of patients who have undergone PTCA, it does not provide follow-up data on the outcome of patients with singlevessel disease compared with those with multivessel disease or address the question of completeness of revascularization."' A complete follow-up of all patients who undergo From the Mayo Clinic and Mayo Foundation, Rochester, MN. Address for correspondence: David R. Holmes, Jr., M.D., Mayo Clinic, 200 First St., SW, Rochester, MN 55905. Received May 11, 1984; revision accepted Dec. 20, 1984. Dr. Mabin was a visiting clinician from the University of Cape Town, Groote Schuur Hospital, Cape Town, South Africa. 754 PTCA at the Mayo Clinic has been maintained. The purpose of this report is to document the continuing follow-up results among these patients, particularly with respect to the need for subsequent intervention, the effect of complete and incomplete revascularization, and the incidence of subsequent cardiovascular events. Materials and methods Patients and selection criteria. From September 1979 to December 1982, 244 patients underwent PTCA at the Mayo Clinic. Fifteen of these patients received streptokinase before or during PTCA, and they were excluded from analysis. The remaining 229 patients formed the basis of this study. All patients had at least 6 months of follow-up, a minimum selected because most restenosis occurs within this time. 13 The criteria for patient selection were (1) symptomatic myocardial ischemia poorly responsive to medical treatment in patients who were candidates for coronary artery surgery and (2) coronary anatomy suitable for dilatation. Stenosis of 70% or greater diameter reduction in the proximal, middle, and distal right coronary artery, in the proximal and middle left anterior descending and first diagonal coronary arteries, or in the proximal and distal circumflex and first and second obtuse marginal coronary arteries (Coronary Artery Surgery Study tCASSI segCIRCULATION by gest on July 5, 2017 http://ciajournals.org/ D ow nladed from THERAPY AND PREVENTION-PTCA ments 1, 2, 3, 12, 13, 15, 18, 19, 20, and 21'4) was considered suitable for PTCA if the segment supplied an area of viable myocardium. The severity of stenosis was assessed in multiple angiographic views and then averaged. Procedural details. PTCA was performed as previously described,2 with cardiovascular surgical standby. All patients gave written informed consent. Steerable balloon catheter systems were not used routinely during this time. In patients with multivessel disease, PTCA was attempted first at the site considered to be the primary cause of the symptoms. This determination was based on the correlation between ischemic electrocardiographic changes, regional left ventricular function, and the lesions found at angiography. If dilatation of the most severe stenosis was unsuccessful, PICA of the other lesions was not attempted. Patients in whom dilatation was unsuccessful usually underwent coronary artery bypass graft surgery (CABG) within 48 hr after the attempt at PTCA. Definitions (1) Single-vessel disease: >70% stenosis of the luminal diameter in only one major epicardial vessel, with all other stenosis <50%. (2) Multivessel disease: -70% stenosis in at least one major epicardial vessel and >50% stenosis in one or more additional major vessels. (3) Successful PICA: reduction of stenosis by >40% of the luminal diameter, without a complication requiring CABG. (Lesions <70% of the luminal diameter usually were not dilated.) (4) Revascularization: Complete successful dilatation of all .70% stenoses. (It follows that in patients with single-vessel disease, successful PTCA should result in complete revascularization.) Partialsuccessful dilatation of at least one significant (>70%) stenosis but with residual stenosis of -70% in one or more vessels (which may or may not have been potentially amenable to PTCA). (5) Restenosis: increase of stenosis by >30% of the luminal diameter immediately after PTCA. Follow-up. Follow-up has been maintained on all patients at 6 month intervals by telephone interview or physical examination. The presence and duration of symptoms and the need for repeat PICA or CABG were recorded at each follow-up. Chest pain was coded as "angina" or "unstable angina" according to the CASS and NHLBI PTCA Registry criteria.11 Myocardial infarction was diagnosed by the presence of two of three criteria: prolonged chest pain requiring hospitalization, Q wave electrocardiographic criteria (Minnesota code), and elevation of creatine kinase or the creatine kinase MB fraction to three times the normal value. Copies of all relevant records were obtained from the patients' home physicians or admitting hospitals when indicated. All patients were encouraged to return for follow-up angiographic examination 6 months after PTCA. Statistical analysis. Chi square analysis was used to test the significance of differences in results and patient characteristics. Event-free survival was computed from the date of the initial attempt at PITCA. For this analysis, the events considered were angina pectoris, myocardial infarction, repeat PTCA, CABG, and cardiac death.