Acute myocardial infarction: Safety of cardiac MR imaging after percutaneous revascularization with stents

Purpose: To retrospectively determine the safety of cardiac magnetic resonance ( MR) imaging performed early ( < 14 days) after coronary stent implantation in patients with acute myocardial infarction ( AMI). Materials and Methods: This HIPPA-compliant study was approved by the institutional review board; the informed consent requirement was waived. Consecutive patients with AMI who underwent cardiac MR imaging ( study group) shortly after stent implantation ( median, 3 days) were compared with control subjects who did not undergo MR imaging and were matched for clinical factors and angiographic extent of coronary disease. A 1.5-T MR imager was used to evaluate cine function, perfusion, and viability. Rates of death, nonfatal myocardial infarction, or revascularization 30 days and 6 months after stent implantation were compared with chi(2) analysis. Results: The study group consisted of 66 patients ( median age, 56 years; 17 women) with 97 stents, 38 ( 39%) of which were drug eluting. The control group included 124 patients ( median age, 58 years; 23% women) with 197 stents, 21 ( 10.7%) of which were drug eluting. There was no significant ( P = .13) difference in the combined end point of death, nonfatal myocardial infarction, or revascularization between the study ( 2.0% [ 95% confidence interval: 0.0%, 4.5%]) and control ( 6.5% [ 95% confidence interval: 1.6%, 11.3%]) groups at 30-day follow-up. The event-free survival rate at 6-month follow-up was 91% in the study group and 83.7% in the control group ( P = .18). Considering the end points separately, there was no difference in the event rate at 30-day or 6-month follow-up between groups. No adverse cardiovascular events occurred in patients with drug-eluting stents who underwent MR imaging. Conclusion: Cardiac MR imaging performed shortly after AMI and percutaneous revascularization with bare metal or drug-eluting stents appears safe. The risk of adverse cardiovascular events is low and similar to that in patients who do not undergo MR imaging.