Background: Impairment of renal function (IRF) is an independent risk factor of myocardial infarction (MI).

Aim: The aim of study was to determine if the presence of IRF affects the choice of treatment strategy in patients with MI, and if long-term mortality rates are influenced by the use of an invasive strategy in patients with MI according to the grade of IRF.

Methods: Data from the PL-ACS Registry of 22,431 patients hospitalised for MI during 2007–2008 with an available estimated glomerular filtration rate (eGFR) with 2009 Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula were included. Patients were stratified based on eGFR: ≥ 90 (normal); 60–89 (mild IRF); 30–59 (moderate IRF); 15–29 (severe IRF); and < 15 mL/min/1.73 m² (end-stage IRF).

Results: After adjustment, each increase in IRF grade reduced the likelihood of percutaneous coronary intervention by 19% (odds ratio [OR] 0.81; 95% confidence interval [CI] 0.78–0.85; p < 0.001). A higher IRF grade was independently associated with mortality (OR 2.01; 95% CI 1.86–2.18; p < 0.001) and major bleeding (OR 1.42; 95% CI 1.22–1.66; p < 0.001) during hospitalisation, and mortality at 12 (hazard ratio [HR] 1.55; 95% CI 1.49–1.62; p < 0.001) and 36 months (HR 1.50; 95% CI 1.45–1.55; p < 0.001). Invasive treatment was independently associated with improved 12-month prognosis in non-ST-segment elevation MI (NSTEMI) patients with mild-to-severe IRF and in ST-elevation MI (STEMI) patients at all IRF grades.

Conclusions: Invasive procedures were less frequent with worsening renal dysfunction. Invasive treatment was associ­ated with improved 12-month prognosis in STEMI patients regardless of renal function and in NSTEMI patients with eGFR ≥ 15 mL/min/1.73 m².