Long-term outcomes after acute kidney injury in myocardial infarction complicated by cardiogenic shock - a retrospective, observational study

AIMS: The recent DanGer shock trial found reduced mortality, but increased risk of acute kidney injury (AKI) in patients treated with a microaxial flow pump after an acute myocardial infarct with cardiogenic shock. AKI has previously been associated with increased short-term mortality, whereas data on long-term outcomes are sparse. We aimed to describe the frequency of AKI and associated risk factors as well as long-term mortality and morbidity.

METHODS AND RESULTS: A retrospective observational study comprising patients admitted with acute myocardial infarction cardiogenic shock in Denmark between 2010 and 2017 with data on kidney function from the RETROSHOCK cohort. National health registry data enabled 10-year follow-up to assess mortality and morbidity. Kaplan-Meier estimates and competing risks regression were used to evaluate the association of AKI with the incidence of short- and long-term mortality, chronic kidney disease (CKD) and dialysis. Among 1473 patients, 44% developed AKI, 25% required renal replacement therapy (RRT). AKI development was associated with increasing age, diabetes, low ejection fraction and high lactate levels on admission (P < 0.05). Thirty-days mortality as well as mortality at 1-, 5-, and 10-years follow-up was significantly increased in patients with AKI; at 10 years follow-up mortality was increased by more than 30% (P < 0.001). The 10-year cumulative incidence of both CKD and dialysis, accounting for the competing risk of death, was significantly higher in patients treated with RRT during admission (P < 0.001).

CONCLUSION: AKI was associated with increased short- and long-term mortality and morbidity, including CKD and dialysis, but not new cardiovascular events.