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.
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.
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.
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.