Background: Compared with balloon angioplasty, stenting has been established as an effective treatment modality to reduce restenosis in patients with acute myocardial infarction. However, the immediate results that predict favorable long-term outcomes in the acute infarct stenting are unknown. Therefore, we evaluated long-term outcomes of stenting for infarct-related artery (IRA) lesions by using intravascular ultrasound (IVUS) compared with that of stenting for non-IRA lesions.
Methods: IVUS-guided coronary stenting was successfully performed in 510 native coronary lesions (105 IRA vs 405 non-IRA). A 6-month follow-up angiogram was performed in 419 (82.2%) lesions: 87 (82.9%) IRA lesions and 332 (82.0%) non-IRA lesions. Coronary stenting on the IRA lesions was successfully performed within 7 to 10 days after onset of infarction in 42 patients and within 12 hours in 45 patients. Results were evaluated by clinical, angiographic, and IVUS methods.
Results: There were no significant differences in clinical and angiographic variables between the two groups. IVUS variables including reference vessel area and minimal stent area were also similar between the two groups. There was no significant difference in angiographic restenosis rate between the two groups in cases of minimal stent area > or = 7 mm(2): 12.8% (6 of 47) in IRA versus 19.1% (33 of 173) in non-IRA lesions (P = .315). However, the angiographic restenosis rate in cases of minimal stent area <7 mm(2) was 50% (20 of 40) in IRA lesions versus 31.5% (50 of 159) in non-IRA lesions (P = .028).
Conclusions: Angiographic restenosis is significantly higher in stenting for IRA lesions compared with that for non-IRA lesions in cases of minimal stent area < 7 mm(2).