Effect of acute kidney injury on long-term mortality in patients with ST-segment elevation myocardial infarction complicated by cardiogenic shock who underwent primary percutaneous coronary intervention in a high-volume tertiary center

OBJECTIVE
Acute kidney injury (AKI) is a reflection of both renal and cardiac reserve in patients with ST-segment elevation myocardial infarction (STEMI), but there is a lack of evidence related to the effect of AKI on long-term mortality in patients with STEMI. This study was an investigation of the prognostic value of AKI for long-term mortality in patients with STEMI complicated by cardiogenic shock (CS) and primary percutaneous coronary intervention (PPCI).

METHODS
This retrospective analysis evaluated the long-term prognostic impact of AKI on 492 patients with STEMI complicated by CS who were treated with PPCI. AKI was defined as ≥0.3mg/dL increase in serum creatinine within 48 hours or a ≥50% increase in serum creatinine in 7 days, or a reduction in urine output (documented oliguria of less than 0.5mL/kg per hour >6 hours. Patients were grouped according to the incidence of AKI and long-term mortality was compared. Cox regression analysis was used to determine independent prognostic factors of long-term mortality.

RESULTS
In Cox regression analysis, the age- and sex- adjusted hazard ratios (HRs) were higher for all-cause mortality in patients with AKI. [HR: 4.556; 95% confidence interval: (CI) 2.370–8.759]. After adjustment for confounding variables, the relative risk was greater for patients with AKI in comparison with patients without AKI (HR: 2.207; 95% CI: 1.150–4.739). Age (HR: 1.060, 95% CI: 1.027–1.094; p<0.001), left ventricular ejection fraction (HR: 0.952, 95% CI: 0.916–0.989; p=0.012), blood urea nitrogen level (HR: 1.019, 95% CI: 1.005–1.034; p=0.010), and AKI (HR: 2.244, 95% CI: 1.077–4.676; p=0.031) were found to be independent factors to determine long-term mortality.

CONCLUSION
The results of this study demonstrated that AKI was an independent prognostic factor for long-term mortality among patients with STEMI complicated by CS and treated with PPCI.