Impact of acute kidney injury on in-hospital outcomes among patients hospitalized with acute heart failure - A propensity-score matched analysis

Aim: We sought to determine the impact of acute kidney injury (AKI) on in-hospital outcomes in patients presenting with acute heart failure (AHF). Data from National Inpatient Sample (2012- 14) were used to identify patients with the principal diagnosis of AHF and the concomitant secondary diagnosis of AKI.

Methods: Propensity score matching was performed on 30 baseline variables to identify a matched cohort. The outcome of interest was in-hospital mortality. We further evaluated in-hospital procedures and complications.

Results: Of 1,470,450 patients admitted with AHF, 24.3% had AKI. After propensity matching a matched cohort of 356,940 patients was identified. In this matched group, the AKI group had significantly higher in-hospital mortality (3.8% vs 1.7%, p<0.001). Complications such as sepsis, transfusions and cardiac arrest were also higher in the AKI group (p<0.01). Similarly, in-hospital procedures including pacemaker, coronary artery bypass graft, mechanical ventilation and intra-aortic balloon pump were performed more in the AKI group compared to the non-AKI group. The rate of AKI in patients with AHF has gradually increased from 29 % in the year 2012 to 35% in 2014. AHF patients with AKI had longer in-hospital stay of ~1.7 days.

Conclusion: In this propensity score-matched cohort of AHF with and without AKI, the risk of in-hospital mortality was >2-fold in the AKI group. Healthcare utilization and burden of complications were higher in the AKI group.