Three-year risk of cardiovascular disease among intensive care patients with acute kidney injury: a population-based cohort study

Abstract

IntroductionAcute kidney injury (AKI) is common among intensive care unit (ICU) patients, but follow-up data on subsequent risk of cardiovascular disease remain sparse. We examined the impact of AKI on three-year risk of first-time heart failure, myocardial infarction (MI), and stroke among ICU patients surviving to hospital discharge, and whether this risk is modified by renal recovery before hospital discharge.MethodsWe used population-based medical registries to identify all adult patients admitted to an ICU in Northern Denmark between 2005 and 2010 who survived to hospital discharge and who had no previous or concurrent diagnosis of heart failure, MI, or stroke. AKI was defined according to the creatinine criteria in the Kidney Disease Improving Global Outcomes classification. We computed the three-year cumulative risk of hospitalization with heart failure, MI, and stroke for patients with and without AKI and the hazard ratios (HRs), using a Cox model adjusted for potential confounders.ResultsAmong 21,556 ICU patients surviving to hospital discharge, 4,792 (22.2%) had an AKI episode. Three-year cumulative risk of heart failure was 2.2% in patients without AKI, 5.0% for AKI stage 1, and 5.0% for stages 2 to 3. The corresponding adjusted HRs were 1.33 (95% confidence interval (CI), 1.06 to 1.66) for patients with AKI stage 1 and 1.45 (95% CI, 1.14 to 1.84) for AKI stages 2 to 3, compared to patients without AKI. The three-year cumulative MI risk was 1.0% for patients without AKI, 1.8% for patients with AKI stage 1 and 2.3% for patients with AKI stages 2 to 3. The adjusted HR for MI was 1.04 (95% CI, 0.71 to 1.51) for patients with AKI stage 1 and 1.51 (95% CI, 1.05 to 2.18) for patients with AKI stages 2 to 3, compared with patients without AKI. We found no association between AKI and stroke. The increased risk of heart failure and MI persisted in patients with renal recovery before discharge, although it was less pronounced than in patients without renal recovery.ConclusionsICU patients surviving any stage of AKI are at increased three-year risk of heart failure, but not stroke. Only AKI stages 2 to 3 are associated with increased MI risk.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-014-0492-2) contains supplementary material, which is available to authorized users.

Recovery from AKI in the critically ill: potential confounders in the evaluation

“…Whether the absence of AKI criteria or stricter definitions of recovery are more appropriate requires further investigation on the relationship of these definitions of recovery with longterm patient and kidney outcome. Imputation of baseline Screat in patients with unavailable baseline is proposed by both ADQI and KDIGO [28] and was actually used in several clinical trials on AKI recovery [4,16,17,23,25]. We noted that patients with unknown baseline Screat had less complete recovery when compared with those with available baseline.…”

“…Even a complete recovery from AKI has been suggested to predispose to long-term adverse outcomes [3][4][5][6][7][8], whereas available studies are often small and limited to specific surgical populations [19-21, 26, 27], used only administrative or laboratory databases [10,11,25], or also included non-ICU patients [10,11,15,17,22,24,25].…”

“…The majority of the available studies reported recovery at hospital discharge [17,[19][20][21][22][23][24][25]. With the exception of studies focusing on long-term follow-up [4,5,10], recovery is mostly reported for all AKI patients (survivors and non-survivors) [15,16,18,19,[21][22][23]26].…”

“…The available clinical trials either excluded patients with an unknown baseline Screat [9,19], used an imputed baseline Screat based on the Modification of Diet in Renal Disease (MDRD) equation (as suggested by ADQI and KDIGO) [4,16,17,23,25], used the minimum Screat measured during hospitalization [5,21], or did not mention how baseline Screat was determined [18,24]. The impact of using an imputed instead of the observed baseline on the incidence of AKI has been reported [30][31][32].…”

Care of the Acute Kidney Injury Survivor

“…Several studies have highlighted the relationship between AKI and subsequent myocardial infarction [8], stroke [9] and heart failure [10, 11]. Most recently, Chawla et al[6] highlighted that among veterans admitted with a myocardial infarction, super-imposed AKI during the index hospitalization portended a higher risk of major adverse cardiovascular events (defined as the composite of stroke, heart failure or recurrent myocardial infarction) over the ensuing follow-up that extended to 6 years (aHR 1.24, 95% CI 1.18–1.30 as compared to patients with a myocardial infarction uncomplicated by AKI) [6].…”