Long-term renal outcomes and mortality following renal injury among myocardial infarction patients treated by primary percutaneous intervention

OBJECTIVES: Limited data are present on persistent renal impairment following acute kidney injury (AKI) among ST elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). We evaluated the incidence and prognostic implications of acute kidney disease (AKD), defined as reduced kidney function for the duration of between 7 and 90 days after exposure to an AKI initiating event, as well as long-term renal outcomes among STEMI patients undergoing primary PCI who developed AKI. PATIENTS AND METHODS: We retrospectively studied 225 consecutive STEMI patients who developed AKI. Patients were assessed for the occurrence of AKD and long-term renal outcomes on the basis of serum creatinine levels measured at 7 days/hospital discharge and within 90-180 days of renal insult. Mortality was assessed at 90 days and over a period of 1271±903 days (range: 2-2130 days) following the renal insult. RESULTS: Progression to AKD occurred in 81/225 (36%) patients and was associated with higher 90-day (35 vs. 11%, P<0.001) and long-term mortality (35 vs. 17%, P<0.001). Normalization of serum creatinine to a level equal/lower than hospital admission level at more than 90 days from renal insult occurred in 41% of patients with AKD, whereas 59% of these patients showed new/progressed chronic kidney disease. In contrast, only 7% of patients without AKD showed the progression of pre-existing renal disease while, in the rest, the serum creatinine level remained stable. CONCLUSION: Progression to AKD following an acute renal insult in STEMI is frequent and associated with worse survival and adverse long-term renal outcomes.