Acute Kidney Injury and Risk of Heart Failure and Atherosclerotic Events

Abstract

Background and objectives: AKI in the hospital is common and is associated with excess mortality. We examined whether AKI is also independently associated with a higher risk of different cardiovascular events in the first year after discharge.

Design, setting, participants, & measurements: We conducted a retrospective analysis of a cohort between 2006 and 2013 with follow-up through 2014, within Kaiser Permanente Northern California. We identified all adults admitted to 21 hospitals who had one or more in-hospital serum creatinine test result and survived to discharge. Occurrence of AKI was on the basis of Kidney Disease: Improving Global Outcomes diagnostic criteria. Potential confounders were identified from comprehensive inpatient and outpatient, laboratory, and pharmacy electronic medical records. During the 365 days after discharge, we ascertained occurrence of heart failure, acute coronary syndromes, peripheral artery disease, and ischemic stroke events from electronic medical records.

Results: Among a matched cohort of 146,941 hospitalized adults, 31,245 experienced AKI. At 365 days postdischarge, AKI was independently associated with higher rates of the composite outcome of hospitalization for heart failure and atherosclerotic events (adjusted hazard ratio [aHR], 1.18; 95% confidence interval [95% CI], 1.13 to 1.25) even after adjustment for demographics, comorbidities, preadmission eGFR and proteinuria, heart failure and sepsis complicating the hospitalization, intensive care unit (ICU) admission, length of stay, and predicted in-hospital mortality. This was driven by an excess risk of subsequent heart failure (aHR, 1.44; 95% CI, 1.33 to 1.56), whereas there was no significant association with follow-up atherosclerotic events (aHR, 1.05; 95% CI, 0.98 to 1.12).

Conclusions: AKI is independently associated with a higher risk of cardiovascular events, especially heart failure, after hospital discharge.

Keywords: Acute Coronary Syndrome; Acute Kidney Injury; Adult; Brain Ischemia; Comorbidity; Electronic Health Records; Follow-up Studies; Hospital Mortality; Inpatients; Intensive Care Units; Kidney Function Tests; Length Of Stay; Outpatients; Patient Discharge; Peripheral Arterial Disease; Retrospective Studies; Sepsis; Stroke; cardiovascular disease; creatinine; glomerular filtration rate; heart failure; hospitalization; mortality; proteinuria.

Copyright © 2018 by the American Society of Nephrology.

Figures

Graphical abstract

Figure 1.

Cohort assembly of adults hospitalized between January 1, 2006 and December 31, 2013. AKI defined using modified KDIGO criteria: increase in serum creatinine by ≥0.3 mg/dl (≥26.5 μmol/l) within 48 hours or an increase in serum creatinine to ≥1.5 times baseline (defined as the most recent nonemergency department, outpatient value in the 7–365 days before admission). SCr, serum creatinine.

Figure 2.

Cumulative incidence of heart failure or atherosclerotic events at 365 days after discharge higher among hospitalized adults who did or did not experience AKI.

Figure 3.

AKI is independently associated with all cardiovascular events, heart failure, and death, but not with individual atherosclerotic events at 365 days after discharge among hospitalized adults. All models adjusted for matching strata, race, prior medical history (coronary heart disease, heart failure, peripheral arterial disease, stroke, atrial fibrillation/flutter, hypertension, diabetes, and cancer), preadmission eGFR and documented proteinuria, diagnosis of selected medical conditions during the hospitalization (heart failure, sepsis), admission to the ICU, length of stay, predicted mortality score, and receipt of dialysis and/or transplant during follow-up.