Contemporary incidence, predictors, and outcomes of acute kidney injury in patients undergoing percutaneous coronary interventions: insights from the NCDR Cath-PCI registry

Abstract

Objectives: This study sought to examine the contemporary incidence, predictors and outcomes of acute kidney injury in patients undergoing percutaneous coronary interventions.

Background: Acute kidney injury (AKI) is a serious and potentially preventable complication of percutaneous coronary interventions (PCIs) that is associated with adverse outcomes. The contemporary incidence, predictors, and outcomes of AKI are not well defined, and clarifying these can help identify high-risk patients for proactive prevention.

Methods: A total of 985,737 consecutive patients underwent PCIs at 1,253 sites participating in the National Cardiovascular Data Registry Cath-PCI registry from June 2009 through June 2011. AKI was defined on the basis of changes in serum creatinine level in the hospital according to the Acute Kidney Injury Network (AKIN) criteria. Using multivariable regression analyses with generalized estimating equations, we identified patient characteristics associated with AKI.

Results: Overall, 69,658 (7.1%) patients experienced AKI, with 3,005 (0.3%) requiring new dialysis. On multivariable analyses, the factors most strongly associated with development of AKI included ST-segment elevation myocardial infarction (STEMI) presentation (odds ratio [OR]: 2.60; 95% confidence interval [CI]: 2.53 to 2.67), severe chronic kidney disease (OR: 3.59; 95% CI: 3.47 to 3.71), and cardiogenic shock (OR: 2.92; 95% CI: 2.80 to 3.04). The in-hospital mortality rate was 9.7% for patients with AKI and 34% for those requiring dialysis compared with 0.5% for patients without AKI (p < 0.001). After multivariable adjustment, AKI (OR: 7.8; 95% CI: 7.4 to 8.1, p < 0.001) and dialysis (OR: 21.7; 95% CI: 19.6 to 24.1; p < 0.001) remained independent predictors of in-hospital mortality.

Conclusions: Approximately 7% of patients undergoing a PCI experience AKI, which is strongly associated with in-hospital mortality. Defining strategies to minimize the risk of AKI in patients undergoing PCI are needed to improve the safety and outcomes of the procedure.

Keywords: ACC; AKI; AKI-D; AKIN; Acute Kidney Injury Network; American College of Cardiology; CI; CKD; MI; NCDR; National Cardiovascular Data Registry; OR; PCI; ST-segment elevation myocardial infarction; STEMI; acute kidney injury; acute kidney injury requiring dialysis; chronic kidney disease; confidence interval; eGFR; estimated glomerular filtration rate; myocardial infarction; odds ratio; percutaneous coronary intervention; stent(s).

Figure 1. Population Selection Flow Diagram

Initial cohort and cohort exclusions. EX = exclusion; PCI = percutaneous coronary intervention.

Figure 2. Incidence of Acute Kidney Injury or Dialysis

The incidence of acute kidney injury as defined by the Acute Kidney Injury Network (AKIN) definitions. AKIN 1, ≥0.3 mg/dl absolute or 1.5- to 2.0-fold relative increase in serum creatinine; AKIN 2, >2- to 3-fold increase in serum creatinine; AKIN 3, >3-fold increase in serum creatinine or serum creatinine >4.0 mg/dl with an acute increase of >0.5 mg/dl. Dialysis was an in-hospital outcome identified using a pre-defined National Cardiovascular Data Registry data element for acute or worsening renal failure, necessitating new renal dialysis.

Figure 3. Incidence of AKI or Dialysis Stratified by Severity of Chronic Kidney Disease

(A) AKI and dialysis by GFR level: all patients. (B) AKI and dialysis by GFR level: ST-segment elevation myocardial infarction (STEMI) patients. The incidence of AKI on the left y-axis and dialysis on the right y-axis stratified by baseline chronic kidney disease as defined by a patient’s GFR. GFR was calculated using the Modification of Diet in Renal Disease equation on the basis of the patient’s pre-procedure serum creatinine level. (A) All patients. (B) Only patients presenting with STEMI. AKI = acute kidney injury; AKIN = Acute Kidney Injury Network; GFR = glomerular filtration rate; STEMI = ST-segment elevation myocardial infarction.

Figure 4. Independent Predictors of AKI or Dialysis

(A) Independent predictors of any AKI (including dialysis). (B) Independent predictors of dialysis only. Odds ratios were calculated using logistic regression with generalized estimating equation methods. ACS = acute coronary syndrome; CVD = cerebrovascular disease; DM = diabetes mellitus; HF = heart failure; IABP = intra-aortic balloon pump; NSTEMI/UA = non–ST-segment elevation myocardial infarction/unstable angina; other abbreviations as in Figure 3.

Figure 5. Risk of Death, Bleeding, and Myocardial Infarction in Patients With AKI and/or Dialysis

The incidence of death, bleeding, and MI stratified by the absence and presence of AKI and the presence of dialysis. MI = myocardial infarction; other abbreviations as in Figure 3.

Figure 6. Independent Predictors of Bleeding, MI, and Death

(A) Independent predictors of death. (B) Independent predictors of major bleeding. (C) Independent predictors of myocardial infarction. Odds ratios were calculated using logistic regression with generalized estimating equation methods. Card Shock = cardiogenic shock; CHF = congestive heart failure; CLD = chronic lung disease; GFR - 10 = every 10-unit decrease in glomerular filtration rate; PVD = peripheral vascular disease; NYHA = New York Heart Association; other abbreviations as in Figures 3 and 5.