Clinically significant contrast induced acute kidney injury after non-emergent cardiac catheterization - risk factors and impact on length of hospital stay

ABSTRACT

To evaluate the frequency and risk factors associated with clinically significant contrast-induced nephropathy [CIN] in patients undergoing non-emergent coronary angiography. Descriptive study. The Aga Khan University Hospital, Karachi, from January 2005 to December 2007. Case records of patients who underwent coronary angiography with a serum creatinine of >/= 1.5 mg/dl at the time of procedure were evaluated. Clinically significant contrast induced nephropathy [CSCIN] was defined as either doubling of serum creatinine from baseline value within a week following the procedure or need for emergency hemodialysis after the procedure. One hundred and sixteen patients met the inclusion criteria. Mean age was 64.0 +/- 11.5 years, 72% were males. Overall prevalence of CIN was 17% [rise of serum creatinine by >/= 0.5 mg/dl] while that of clinically significant CIN [CSCIN] was 9.5% [11 patients]. Patients with CSCIN had significantly lower left ventricular ejection fraction [p = 0.03, OR 0.24; 95% CI = 0.06 - 0.91] and higher prevalence of cerebrovascular disease [p < 0.001, OR 14.66; 95% CI = 3.30 - 65.08]. Mean baseline serum creatinine was significantly higher, 3.0 +/- 1.5 vs. 2.0 +/- 1.1 mg/dl [p = 0.03, OR 1.47; 95% CI = 1.03 - 2.11] whereas mean GFR estimated by Cockcroft-Gault formula was significantly lower at 25 +/- 7.4 vs. 41.0 +/- 14.6 ml/minute [p = 0.001, OR = 0.89, 95% CI = 0.84 - 0.95] at the time of procedure in patients with CSCIN. Mean length of hospital stay was significantly higher in this group compared to those without CIN, 9.0 +/- 5.1 vs. 3.0 +/- 3.2 days [p = 0.001, OR = 1.31, 95% CI = 1.12 - 1.54]. Multivariate analysis revealed low GFR [p = 0.001, OR = 0.88; 95% CI = 0.82 - 0.95] and low ejection fraction [p = 0.03, OR = 0.20; 95% CI = 0.04 - 0.91] to be independent factors associated with CSCIN. No significant differences were noted between the two groups in patients with hypertension, diabetes and heart failure. CSCIN is a significant concern in high risk groups despite prophylaxis. Patients with lower EF, cerebrovascular disease and low GFR at the time of procedure are more likely to have CIN.