Incidence and mortality of acute kidney injury after myocardial infarction: a comparison between KDIGO and RIFLE criteria.

BACKGROUND: Acute kidney injury (AKI) increases the risk of death after acute myocardial infarction (AMI). Recently, a new AKI definition was proposed by the Kidney Disease Improving Global Outcomes (KDIGO) organization. The aim of the current study was to compare the incidence and the early and late mortality of AKI diagnosed by RIFLE and KDIGO criteria in the first 7 days of hospitalization due to an AMI. METHODS AND RESULTS: In total, 1,050 AMI patients were prospectively studied. AKI defined by RIFLE and KDIGO occurred in 14.8% and 36.6% of patients, respectively. By applying multivariate Cox analysis, AKI was associated with an increased adjusted hazard ratio (AHR) for 30-day death of 3.51 (95% confidence interval [CI] 2.35-5.25, p<0.001) by RIFLE and 3.99 (CI 2.59-6.15, p<0.001) by KDIGO and with an AHR for 1-year mortality of 1.84 (CI 1.12-3.01, p=0.016) by RIFLE and 2.43 (CI 1.62-3.62, p<0.001) by KDIGO. The subgroup of patients diagnosed as non-AKI by RIFLE but as AKI by KDIGO criteria had also an increased AHR for death of 2.55 (1.52-4.28) at 30 days and 2.28 (CI 1.46-3.54) at 1 year (p<0.001). CONCLUSIONS: KDIGO criteria detected substantially more AKI patients than RIFLE among AMI patients. Patients diagnosed as AKI by KDIGO but not RIFLE criteria had a significantly higher early and late mortality. In this study KDIGO criteria were more suitable for AKI diagnosis in AMI patients than RIFLE criteria

Hospital admission eGFR, AKI development and 30-day mortality rates after acute myocardial infarction.

<p>Hazard ratio (Cox multivariate analysis, left) and crude mortality (right).</p

Baseline clinical characteristics and medical therapy during hospitalization of AKI versus non-AKI patients according to the two AKI criteria used.

<p>Continuous variables are presented as medians (with interquartile ranges), and categorical variables are presented as percentages. AKI, acute kidney injury; RIFLE, Risk, Injury, Failure, Loss, and End-stage kidney Disease; KDIGO, Kidney Disease: Improving Global Outcomes; HTN, hypertension; HCL, hypercholesterolemia; EVD, extracardiac vascular disease; CAD, coronary artery disease; CABG, coronary artery bypass graft; ACEIs, angiotensin-converting enzyme inhibitors; ARBs, angiotensin II receptor blockers; STEMI, ST-segment elevation myocardial infarction; SBP, systolic blood pressure; HR, heart rate; SCr, serum creatinine; eGFR, estimated glomerular filtration rate; PCI, percutaneous coronary intervention; LVD, left ventricular dysfunction.</p>*<p>n = 1049;</p>†<p>n = 1040;</p>‡<p>n = 518 (only for STEMI patients);</p>§<p>Primary or non-primary;</p>||<p>with PCI or thrombolytics;</p>#<p>n = 9.</p

Cox proportional hazards model for 30-day to 1-year mortality^*.

*<p>Estimated for patients who survived for 30 days after AMI.</p><p>eGFR, estimated glomerular filtration rate (mL/min/1.73 m²); AKI, acute kidney injury; AHR, adjusted hazard ratio; CI, confidence interval.</p><p>The model was adjusted for age, admission glycemia (categorized by quartiles with the first as a reference), gender (females were used as the reference), ST elevation myocardial infarction, history of diabetes, history of hypertension, prior use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, admission Killip class >I, admission heart rate >100 beats/min, clopidogrel use during hospitalization, diuretics use, coronary angiography during hospitalization, reinfarction, severe systolic left ventricular dysfunction and any percutaneous coronary intervention performed during hospitalization.</p

Serum creatinine criteria for defining and staging AKI^*.

<p>AKI, acute kidney injury; RIFLE, Risk, Injury, Failure, Loss, and End-stage kidney Disease; SCr, serum creatinine. KDIGO, Kidney Disease: Improving Global Outcomes.</p>*<p>Modified from references <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069998#pone.0069998-Bellomo1" target="_blank">[12]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0069998#pone.0069998-Kidney1" target="_blank">[14]</a>.</p>†<p>Only the SCr criteria were used to diagnose and stage AKI and therefore glomerular filtration rate and urinary output criteria were omitted.</p

Cox proportional hazard models for the association between 30-day to 1-year mortality and AKI according to the different AKI criteria used.

<p>AKI, acute kidney injury; AHR, adjusted hazard ratio; CI, confidence interval; RIFLE, Risk, Injury, Failure, Loss, and End-stage kidney Disease; KDIGO, Kidney Disease: Improving Global Outcomes.</p><p>The model was adjusted for age, admission estimated glomerular filtration rate, history of hypertension and diabetes, history of extracardiac vascular disease, prior use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, admission Killip class, admission heart rate, admission glycemia, clopidogrel use during hospitalization, therapy with diuretics, coronary angiography during hospitalization, reperfusion therapy with primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction, any type of revascularization with either PCI or coronary artery bypass graft performed during hospitalization or severe systolic left ventricular dysfunction.</p>*<p>The AHR was estimated for each set of criteria, considering patients without AKI for each.</p

Hospital admission eGFR, AKI development and 30-day to 1-year mortality rates after acute myocardial infarction.

<p>Hazard ratio (Cox multivariate analysis, left) and crude mortality (right). Note that only the combination of an admission eGFR<60 mL/min/1.73 m² with AKI was associated with a higher late mortality. * 30-day to 1-year mortality rates were estimated for patients who survived for 30 days after AMI.</p

Comparison of admission characteristics upon hospitalization between patients with not-impaired or impaired admission eGFR.

<p>a-eGFR, admission estimated glomerular filtration rate (mL/min/1.73 m²); PCI, percutaneous coronary intervention; CABG, coronary artery bypass graft; CAD, coronary artery disease; AMI, acute myocardial infarction; ACEI, angiotensin-converting enzyme inhibitors; ARB, angiotensin II receptor blockers; STEMI, ST elevation myocardial infarction; aSBP, admission systolic blood pressure; aHR, admission heart rate. Continuous variables are presented as median values (with interquartile ranges). Categorical variables are presented as percentages.</p>*<p>n = 821 for the total cohort, n = 444 for a-eGFR≥60 mL/min/1.73 m², and n = 377 for a-eGFR<60 mL/min/1.73 m².</p>†<p>n = 827 for the total cohort; n = 380 for a-eGFR<60 mL/min/1.73 m².</p>‡<p>n = 416 (STEMI patients).</p>**<p>comparison between eGFR≥60 and <60 mL/min/1.73 m².</p

Comparison of demographic and clinical characteristics based on admission eGFR and AKI development.

<p>eGFR, estimated glomerular filtration rate (mL/min/1.73 m²); PCI, percutaneous coronary intervention; CABG, coronary artery bypass graft; CAD, coronary artery disease; AMI, acute myocardial infarction; ACEI, angiotensin-converting enzyme inhibitors; ARB, angiotensin II receptor blockers; STEMI, ST elevation myocardial infarction; aSBP, systolic blood pressure; HR, heart rate. Continuous variables are presented as median values (with interquartile ranges) and were analyzed by the Kruskal-Wallis test followed by Dunn's post-test. Categorical variables are presented as percentages and were analyzed by χ² statistics with Bonferroni correction for post-test multiple comparisons.</p>*<p>p<0.001,</p>†<p>p = 0.009,</p>**<p>p = 0.013, admission eGFR≥60, with AKI versus without AKI,</p>‡<p>(beats/min).</p