Effect of acute kidney injury on short-and long-term mortality of patients with acute myocardial infarction

Abstract

Objective To evaluate the role of acute kidney injury (AKI) in predicting the early (30-day) and late (30-day to 5-year) mortality of acute myocardial infarction (AMI) patients during hospitalization. Methods A total of 1371 adult patients diagnosed with AMI in the First People's Hospital of Changzhou from January 2008 to December 2012 were analyzed retrospectively with collecting their relevant clinical data from the hospital's database. AKI was categorized according to the 2012 KDIGO AKI criteria. To compare between death group and non-death group in AMI patients during 30-day and 30-day to 5-year. Different AKI stages of patients were compared, and their all-cause mortality were analyzed by Kaplan-Meier. Using multivariate COX regression analysis with two models to assess the factors for AMI patients in 30-day to 5-year. Results The prevalence of AKI after AMI in death group was higher than that in non-death group (the 30-day prevalence was 72.7% vs 27.4%, P<0.001; the 5-year prevalence was 36.3% vs 26.2%, P=0.013). In both early (30-day) and late (30-day to 5-year) follow up, the KDIGO grading distribution of AKI was different between death group and non-death group (P<0.001 in 30-day follow up and P=0.002 in 30-day to 5-year follow up). Among the 1371 AMI patients, 410 (29.9%) developed AKI during the hospital stay. The 30-day and 30-day to 5-year mortality rates were 5.6% (77/1371) and 11.3% (146/1294) respectively. All-cause mortality and cardiovascular mortality were significantly higher in patients with AKI-Ⅰstage, AKI-Ⅱ stage and AKI-Ⅲ stage than those with non-AKI (all P<0.001), especially in patients with AKI-Ⅲ stage. Further stroke history (HR=3.122, P=0.012), AKI severity (AKI-Ⅰstage HR=3.034, P=0.028; AKI-Ⅱ stage HR=7.832, P<0.001; AKI-Ⅲ stage HR=9.919, P<0.001), and β-blocker therapy (HR=0.591, P=0.040) were independent predictors of 30-day mortality, while aging (HR=1.061, P<0.001), albumin (HR=0.943, P=0.023), AKI-Ⅲ stage (HR=3.944, P=0.007), β-blocker therapy (HR=0.660, P=0.041) and percutaneous coronary intervention (HR=0.256, P<0.001) were independent predictors of 30-day to 5-year mortality. Both at early (30-day) and late (30-day to 5-year) follow-up, AKI with or without baseline renal dysfunction were independent predictors of death in patients with AMI (all P<0.05). Conclusions AKI strongly correlated with short- and long-term all-cause mortality of AMI patients, regardless of the baseline renal impairment. Specifically, the more severe AKI, the higher short-term mortality AMI patients have. Key words: Myocardial infarction; Renal insufficiency, acute; Mortality