Contrast-Induced Nephropathy in Stemi Patients with and Without Chronic Kidney Disease

Background:

Contrast-induced nephropathy (CIN) following percutaneous coronary intervention (PCI) is associated with adverse outcomes; however, there is scarce data comparing clinical outcomes of post-PCI CIN in STEMI patients with and without chronic kidney disease (CKD). A recent study proposed a fluid hydration protocol guided by the measurement of left ventricular end diastolic pressures for CIN prevention in patients undergoing PCI. We sought to assess the incidence, clinical predictors, short-term and long-term clinical outcomes of post-PCI CIN in STEMI patients with and without CKD.

Methods:

We performed a retrospective observational cohort study involving 554 patients who underwent PCI for STEMI from February 2010 to November 2013. CKD was defined as eGFR ≤ 60 mL/min and CIN as creatinine increase by ≥25% or ≥0.5 mg/dL from baseline within 72 hours after catheterization contrast exposure. Univariate and multivariable logistic regression models utilizing backwards selection were used to identify independent predictors of CIN.

Results:

In the entire population, 89 (16%) patients developed CIN. Among CKD patients, the incidence of CIN was 19.7 % (27/137) versus 11.1% (62/417) in non-CKD patients, p<0.05. Univariate analysis revealed that, compared to the non-CIN cohort, patients who developed CIN were older (65 years vs 59 years, p <0.001), had higher incidence of diabetes (35% vs 21%, p<0.005), peripheral artery disease (11% vs 5%, p<0.001), post-procedure cardiogenic shock (24% vs 13%, p<0.05), hemodynamic support requirement (34% vs 14%, p<0.001) and higher Mehran score (9.4±7 vs 5.4±5.2, p<0.001). The strongest predictors of CIN determined by multivariate analysis were Diabetes (OR 5.8, CI 1.8-18.6, p 0.003), door-to-balloon time in hours (OR 1.1, CI 1.09-1.16, p 0.02) and Mehran score (OR 1.2, CI 1.07-1.17, p< 0.001). Compared to patients without CIN, patients with CIN had higher rates of inpatient mortality (14.6% vs. 2.8%, p<0.001), longer length of hospitalization (8 ± 11 days vs. 3.4 ± 4.4 days, p<0.001), need for inpatient dialysis (11.2% vs 0%, p<0.001), higher 30-day mortality (14.6% vs. 3.0%, p<0.001) and higher incidence of long-term serum creatinine > 0.5 mg/dL from baseline (16.9% vs 2.4%, p<0.001). Moreover, both CKD and non-CKD patients who developed CIN had significantly higher inpatient and 30-day mortality, need for inpatient dialysis, length of hospitalization and long-term serum creatinine increase > 0.5mg/dL.

Conclusions:

CKD patients undergoing PCI for STEMI have a higher incidence of CIN than non-CKD patients. CIN confers worse short-term and long-term outcomes irrespective of baseline renal function. Preventative strategies are warranted in all patients presenting with STEMI, irrespective of their baseline renal function.