Systemic Hypothermia to Prevent Radiocontrast Nephropathy (From the COOL-RCN Randomized Trial)

Study Questions:

Can therapeutic hypothermia prevent contrast-induced nephropathy (CIN)?


The COOL-RCN (Cooling to Prevent Radiocontrast Nephropathy) trial authors randomized 128 patients undergoing contrast-based invasive cardiac procedures to therapeutic hypothermia or usual care. Systemic hypothermia (33-34°C) was established before first contrast injection, and maintained for 3 hours after the procedure. Serum creatinine levels at baseline, 24 hours, 48 hours, and 72-96 hours were measured at a central core laboratory. The primary efficacy endpoint was development of CIN and was defined as an increase in serum creatinine by >25% from baseline. The primary safety endpoint was 30-day composite rate of adverse events consisting of death, myocardial infarction, dialysis, ventricular fibrillation, venous complication requiring surgery, major bleeding requiring transfusion >2 U, or rehospitalization.


The study was terminated prematurely due to financial insolvency of the sponsor. There was no difference in the incidence of CIN between those with usual care versus hypothermia (18.6% vs. 22.4%; odds ratio, 1.27; 95% confidence interval, 0.53-3.00; p = 0.59). There was no difference in the primary safety endpoint (37.1% vs. 37.9%; odds ratio, 0.97; 95% confidence interval, 0.47-1.98; p = 0.93).


The authors concluded that therapeutic hypothermia was not associated with a reduction in CIN.


This study (although prematurely terminated) suggests that therapeutic hypothermia is ineffective in preventing CIN. The best strategy for prevention of CIN remains adequate prehydration, minimization of contrast volume, and use of iso-osmolar or selective low osmolar contrast media (Reed et al., JACC Cardiovasc Interv 2009;2:645-54).

Clinical Topics: Arrhythmias and Clinical EP, SCD/Ventricular Arrhythmias

Keywords: Renal Dialysis, Incidence, Myocardial Infarction, Kidney Diseases, Hypothermia, Cardiology, Ventricular Fibrillation

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