Importance of complex additional stenosis after primary angioplasty for acute myocardial infarction in medium-term prognosis

There is some controversy about the ideal type of revascularization in the context of primary angioplasty (percutaneous coronary intervention--PCI) for acute myocardial infarction (AMI). The presence of additional stenosis, especially if complex, can have an impact on prognosis.

To evaluate medium-term (1-year) prognosis according to the presence of complex additional stenosis after primary PCI.

A retrospective study of 138 consecutive patients admitted to our unit for ST-segment elevation AMI who underwent primary PCI. Patients were followed up for 1 year and divided in 2 groups: without complex additional stenosis (n = 69, 61 +/- 14 years, 62% males) and with complex additional stenosis (n = 69, 65 +/- 13 years, 73% males, p = NS). We evaluated demographic characteristics, risk factors for coronary artery disease, previous cardiac history and signs of heart failure on admission. Angiographic characteristics, medication and PCI outcome were also evaluated. The impact of these variables on the combined end-point of death, reinfarction, and myocardial revascularization at 1 year was assessed.

The angiographic success rate was 96.4%. Twenty-four percent of patients were aged 75 years or over and 4.3% of the total population were in Killip class IV on admission. Anterior AMI was slightly more common in the non-complex additional stenosis group (60% vs. 44%, p = 0.06), and inferior AMI in the complex additional stenosis group (26% vs. 42%, p = 0.07). One-vessel disease was more prevalent in the group without complex additional stenosis, as expected (86% vs. 11%, p < 0.001) and stent implantation was also more frequent in this group (96% vs. 86%, p = 0.08). There were no differences in other variables. Death/reinfarction/revascularization was more frequent in the group with complex additional stenosis (13% vs. 32%, p = 0.014). Sixty-seven per cent of the events occurred in the first 30 days of follow-up. At 1 year, univariate predictors of outcome were Killip class > or = 2, TIMI flow < 3 in the infarct-related vessel after PCI, non-use of glycoprotein IIb/IIIa receptor antagonists, beta-blockers or statins, multivessel disease, and the presence of complex additional stenosis (log rank, p = 0.003). Using multivariate regression analysis, the independent predictors of outcome at 1 year were Killip class > or = 2 (OR 0.28; 95% CI 0.08-0.93, p = 0.037) and the presence of complex additional stenosis (OR 0.32; 95% CI 0.12-0.84, p = 0.020).

The presence of complex additional stenosis after primary PCI had a worse prognosis at 1 year, suggesting the need for further interventions to stabilize the plaque, particularly in the first 30 days after AMI.