Impaired renal function in patients with myocardial infarction treated with primary angioplasty and the risk for failed myocardial tissue reperfusion and thus worse long-term outcomes

Aim: The aim was to assess the impact of impaired renal function on myocardial tissue reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI).

Material and methods: Impaired renal function was diagnosed at admission based on abnormal serum creatinine level (> 106 µmol/l). Patients with anterior STEMI and maximal single-lead ST-elevation (maxSTPost) exceeding 2 mm up to 90 min post-procedure, as well as patients with inferior STEMI and maxSTPost > 1 mm, were considered to have failed tissue reperfusion. The incidence of death or heart failure (NYHA class > 2) was prospectively assessed over a subsequent 12-month period.

Results: Primary PCI and maxSTPost measurements were performed in 200 out of 208 consecutive patients (63.0 ±12.1 years, 67.5% males) treated between October 2007 and September 2008. Patients with impaired renal function (12.5%) died or developed heart failure more often when compared to the remaining individuals (56.0% vs. 16.0%, p < 0.001, respectively). Patients with failed reperfusion (15.5%) had higher incidence of one-year mortality and heart failure (35.5% vs. 18.3%, p = 0.032, respectively). Failed tissue reperfusion was 2.5 times more frequent among patients with impaired renal function, despite a relatively high rate of final TIMI 3 flow as compared to the remaining subjects (32.0% vs. 13.1%, p = 0.022 and 84.0% vs. 92.6%, p = 0.239, respectively). Impaired renal function and failed reperfusion were independent predictors of death or heart failure (odds ratio (OR) = 4.38, 95% confidence interval (CI) 1.34-14.28, p = 0.014, and OR = 3.34, 95% CI 1.12-9.88, p = 0.029, respectively). Impaired renal function was a risk factor for failed tissue reperfusion (OR = 2.98, 95% CI 1.03-8.68, p = 0.044).

Conclusions: Impaired renal function in patients with STEMI treated with primary PCI is related to the risk for failed myocardial tissue reperfusion, leading in consequence to higher one-year mortality and heart failure.