Safety, Feasibility, and Hemodynamic Effects of Mild Hypothermia in Transcatheter Aortic Valve Replacement: The TAVR-CHILL Trial

The safety, feasibility, and hemodynamic effects of mild hypothermia (MH) induced by transnasal cooling were studied in transcatheter aortic valve replacement (TAVR). MH is a common therapy following cardiac arrest and seems to have favorable effects in myocardial infarction and on hemodynamic stability. In TAVR, hemodynamic instability is common during rapid pacing. Twenty subjects undergoing TAVR were randomized 1:1 to hypothermia or normothermia. Hemodynamic endpoints were mean arterial blood pressure and required dosage of vasoactive and inotropic drugs. Patients were followed up at 6 months. All patients in the MH group (n=10) reached the target temperature of 34 degrees C before first rapid pacing. Tympanic and urinary bladder temperature remained significantly lower in the MH group during the procedure. No adverse effects of cooling were observed. Mean arterial pressure was higher in the MH group (90 +/- 20mm Hg) than in the control group (71 +/- 13mm Hg) at the start of the procedure, at first rapid pacing (94 +/- 19 vs. 80 +/- 16mm Hg), and at balloon aortic valvuloplasty (90 +/- 17 vs. 73 +/- 14mm Hg). Less norepinephrine was administered to the hypothermia group. Transnasal cooling during TAVR was safe and well tolerated. We observed a more stable hemodynamic profile in the MH group, indicated by higher blood pressure and lower levels of vasoactive drugs required. A larger study of patients with severe ventricular dysfunction is required to more comprehensively investigate the hemodynamic effects of transnasal cooling in TAVR.