Objective: To investigate the characteristics of coronary lesions in patients after first myocardial infarction (MI).
Methods: From May 1998 to December 2000, coronary angiography was performed on 878 consecutive cases who had had first MI within 6 months and without history of previous coronary revascularization, 481 with anterior-lateral MI, 368 with inferior-posterior MI, 19 with posterio-lateral MI, and 10 with location-undetermined MI, and 394 receiving thrombolytic therapy 176 (44.7%) of which were treated successfully, and 525 (59.8%) with history of pre-infarction angina pectoris and 428 (48.7%) with history of post-infarction angina pectoris.
Results: (1) Normal coronary vessels or lesions less than 50% stenosis were seen only in 5.9% (52) of the patients. One-, two- and three-vessel diseases were present in 32.8% (288), 26.4% (232) and 34.9% (306) patients respectively. 3.2% (28) had concomitant left main stem (LMS) disease. Three-vessel coronary disease was significantly more common in the patients with a history of pre-infarction angina in comparison with those without such history (39.2% vs 28.3%, P < 0.01), and was significantly more common in the patients who did not undergo thrombolytic therapy in comparison with those who had received thrombolytic therapy (38.4% vs 30.5%, P < 0.05). (2) Only in 5.1% (41) cases the infarct-related artery (IRA) was normal or with lesions less than 50% stenosis. Total occlusion (100% stenosis), subtotal occlusion (95% to 99% stenosis), severe stenosis (70% to 94% stenosis) and borderline stenosis (50% to 69% stenosis) of IRA were seen in 29.6% (240), 22.6% (183), 37.9% (307) and 4.9% (40) of the cases respectively. Total occlusion of IRA occurred significantly less often in the thrombolytic group than in the non-thrombolytic group (24.6% vs 33.7%, P < 0.01). IRA could not be determined in 67 cases. (3) 90.5% (795), 79.4% (697), 57.2% (502) and 35.6% (313) of the patients had > or = 70% stenosis, > or = 90% stenosis, > or = 95% stenosis and total occlusion coronary lesions in at least one major coronary artery respectively, and coronary revascularization including PCI and CABG was needed on 84% (736/878) of the patients.
Conclusion: Patients with a first MI usually have multi-vessel disease and severe coronary stenosis, with IRA having severe stenotic lesions. Revascularization treatment is needed in the majority of the patients. It is true too for the MI patients without history of pre- or post-infarction angina pectoris and those with successful thrombolytic therapy. Coronary angiography should routinely be performed on the patients who need further coronary revascularization.