Insuficiência renal aguda após intervenção coronária percutânea primária no infarto agudo do miocárdio: preditores e evolução clínica a longo prazo

BACKGROUND: The occurrence of acute renal failure (ARF) is associated with worse clinical outcomes after acute myocardial infarction (AMI), and its nature is multifactorial. The predictors and prognosis for ARF after primary per-cutaneous coronary intervention (PCI) are still not well established. OBJECTIVE: To identify the predictors of ARF in patients submitted to primary PCI and to determine long term clinical evolution. METHODS: This is a retrospective study which includes patients with ST-segment elevation myocardial infarction (STEMI) submitted to primary PCI from January, 2002 to January, 2007. Patients were classified with respect to ARF - an increase in creatinine > 0.5 mg/dl or > 25% from baseline - during hospital stay. Follow-up data were obtained through medical records or by telephone contact to assess major events. RESULTS: A total of 150 patients were enrolled. Mean age was 60 years old and 73% were men. Factors considered risk indicators for ARF such as diabetes mellitus (34%), Killip > 1 (27%), contrast volume and use of potential nephrotoxic drugs were also evaluated. ARF occurred in 15.3% of patients. After multivariate analyses: creatinine > 1.5 mg/dl (OR 3.633 95% CI 1.047-12.613 p = 0.042), older age (OR 1.066 95% Cl 1.002-1.090, p = 0.044), Killip > 1 (OR 3.190 95% Cl 1.025-9.933, p = 0.045) and the need for mechanical ventilation (OR 6.364 95% Cl 2.142-18.910, p = 0.001) were considered independent predictors for ARF. After a year of evolution, death (p = 0.001) and reinfarction (p = 0.048) had shown a significant difference between patients with and without ARF; differences were not found for revascularization (p = 0.305), dialysis (p = 0.281) or combined events (p = 0.060). The differences found for death and reinfarction remained significant after six years of evolution. CONCLUSION: The main predictors of ARF after primary PCI were age, baseline creatinine > 1.5 mg/dl and poor clinical evolution during hospital stay. ARF after primary PCI is a predictor of major events in the short and long-term follow-up.