Inducing hypothermia by a combo infusion of cold saline and use of an endovascular cooling catheter is an effective adjunctive therapy for acute MI patients, according to a study presented Thursday by researchers from Lund University Hospital in Lund, Sweden, at EuroPCR in Paris.
“Experimental studies have shown that induction of hypothermia before reperfusion of acute coronary occlusion reduces infarct size,” the authors wrote. “Previous clinical studies, however, have not been able to show this effect, which is believed to be mainly because therapeutic temperature was not reached before reperfusion in the majority of the patients.”
To alleviate the sparse data, Matthias Götberg, MD, and colleagues evaluated whether inducing hypothermia by an infusion of cold saline and the InnerCool endovascular cooling system (Philips Healthcare) prior to reperfusion would reduce infarct size.
During the pilot study, researchers enrolled 20 STEMI patients who were set to undergo primary PCI. The researchers assessed patient infarct sizes and myocardium risk via cardiac MR using gadolinium-enhanced imaging and T2-weighted imaging.
Before reperfusion, a body temperature of 95 degrees or less was reached without delaying door-to-balloon times—43 minutes and 40 minutes for the hypothermia groups and the control group, respectively.
Additionally results showed that infarct size was reduced by 38 percent in the hypothermia group.
“There are an estimated 240,000 to 260,000 STEMI patients in the U.S. per year receiving primary angioplasty for blockages and another 215,000 to 230,000 in Europe that could potentially benefit from these findings,” the authors wrote.
The researchers attributed the reduction of infarct size to the decline in the release of troponin T in the hypothermia group.
“The protocol demonstrates the ability to safely reach a core body temperature of less than 95 degrees before reperfusion without delaying primary PCI, and that combination hypothermia as an adjunct therapy in AMI resulted in a 38 percent reduction in infarct size,” the authors concluded.