April 25, 2013

Study takes ‘cool’ approach to reducing heart attack damage

Vanderbilt Heart and Vascular Institute is participating in a clinical study to further evaluate the safety and feasibility of rapidly lowering the body’s temperature to significantly reduce the amount of damage caused by a heart attack.

Vanderbilt Heart and Vascular Institute is participating in a clinical study to assess the safety and feasibility of rapidly lowering the body’s temperature to reduce the amount of damage caused by a heart attack.

The randomized, controlled study, called VELOCITY, will enroll 60 patients who are suffering from a specific type of heart attack known as an ST-elevation myocardial infarction (STEMI). Vanderbilt Heart has enrolled two patients so far and is one of several U.S. and Canadian medical centers participating in this investigational trial, which is sponsored by Velomedix Inc.

Participants in the study are randomized to one of two arms. Patients in the control arm receive percutaneous coronary intervention (PCI) without therapeutic hypothermia, which is the current standard treatment for STEMI. Patients in the treatment arm are rapidly cooled first to temperatures of less than 35°C using the Velomedix system just prior to receiving the same PCI treatment.

Three previous randomized controlled trials have shown that patients who are cooled to therapeutic temperatures before the standard treatment for STEMIs have experienced a significant reduction in the extent of the heart attack.

The cooling approach used in the study is unique in its ability to cool patients to the desired temperature in less than 15 minutes.

John McPherson, M.D.

“The principle is to prevent injury to the heart muscle that can occur when we restore normal blood flow to the heart after a heart attack,” said John McPherson, M.D., associate professor of Medicine and principal investigator for the VELOCITY trial.

“By quickly cooling the body before we open the blocked artery, we hope to prevent what is known as reperfusion injury.”

To lower the body temperature, the physician inserts a catheter into the abdomen and then uses the Velomedix system to circulate a large volume of cold fluid in the peritoneal cavity.

This approach provides a unique means of very rapidly removing heat from the patient because a high percentage of blood flows past the cavity at any one time.

Once the body temperature is successfully lowered, the physician opens the artery and puts in a stent.

“The first patient randomized to hypothermia using the Velomedix system at Vanderbilt did well. Performance of the procedure was successful thanks to the great teamwork by our cardiac cath lab staff,” said Pete Fong, M.D., assistant professor of Medicine, who cared for the second patient enrolled in the study.

“We hope therapeutic hypothermia proves to be successful in reducing reperfusion injury.”

For more information on this investigational trial, please refer to ClinicalTrials.gov (NCT01655433).