The Benefits of Delayed Elective Coronary Angioplasty for Acute Myocardial Infarction Patients without Thrombolytic Theraphy : Immediate Results and Angiographic Follow-up

ABSTRACT

BACKGROUND: The value of coronary reperfusion resulting from Thrombolysis and/or coronary angioplasty in patients with evolving myocardial infarction has been rigorously evaluated and improved left venticular function and short-term survival rates have been demonstrated consistently in controlled studies. Benefits from delayed coronary angioplasty at 7-10 days after onset of acute myocardial infarction (AMI) without thrombolysis remains unclear. In order to assess the effect of delayed reperfusion in infarct-related artery(IRA), we analyzed the restenosis rate of IRA after successful coronary angioplasty and the change of left ventricular function at late follow-up angiogram. METHOD: Coronary angioplasty in 69 lesions of 55 patients(M/F48/7, mean age 53 years) with acute myocardial infarction(AMI) were performed at 7-10 days after onset of AMI and follow-up coronary angiogram (25 lesions of 20 pts) with left ventriculogram were obtained at means 5.1 months(range 4-6 months) after angioplasty. Restenosis rate of dilated infaret-related arteries and the changes of left ventricular function after angioplasty were evaluated. RESULTS: The overall procedural success rate of delayed elective coronary angioplasty in patients with AMI was 86% with a higher success rate in subtotally occluded vessel(98%) than in the occluded IRA(64%). Complications included acute closure after large dissection in 1(1.6%) and on -hospital mortality due to cardiogenic shock in 1(1.8%). Angiographically restenosis rate of IRA was 65% at mean 5.1 months follow-up, which was relatively higher than that after non-IRA angioplasty in AMI(25%) and in patients with angina(24%). Left ventricular ejection fraction improved significantly from 47.2+/-12.7% to 58.8+/-8.6%(P<0.05) at follow-up. Patients who had a patent IRA at follow-up had a restenotic IRA at follow-up had no statistically significant improvement in EF(table 3). Patients with a left anterior descending artery(LAD) lesion had lower mean immediate EFs than patients with right coronary artery lesion, however the degree of improvement in EF at follow-up was more significant in patients with LAD lesion. CONCLUSIONS: Delayed elective angioplasty of IRA at 7-10 days after onset of AMI was relatively safe and had comparable procedural success rate. Higher restenosis rate(65%) of IRA at follow-up appeared to be related, at least on part, to the endothelial dysfunction after ischemic-reperfusion injury and clinically unstable status. Left ventricular function improved significantly after angioplasty at follow-up. Recovery of left ventricular function might be reated to whether or not the IRA had an angiographically restenosis at follow-up.