Intense light therapy boosts heart protection after surgery

Intense light therapy after surgery can increase a critical protein that protects heart tissue while lowering levels of troponin, a protein indicating heart damage that's linked to higher mortality in patients undergoing non-cardiac surgery, according to a study by researchers at CU Anschutz.

The study was published this week in the Annals of Translational Medicine.

The results add to a growing body of evidence showing that intense light has a healing effect on the heart and blood vessels, a finding that could help reduce the number of cardiac events that happen after surgery. Myocardial Injuries in Noncardiac Surgeries (MINS) occur in about 20% of patients and significantly increase one year mortality rates.

The risk of myocardial injury goes up after certain surgeries and is significantly higher in patients older than 45. In tests on humans and animal models we found that intense light can significantly reduce troponin release. High levels of troponin following non-cardiac surgery can lead to death. Blocking it could be a very novel therapy for MINS – a disease without therapy."

Tobias de la Garza Eckle, MD, PhD, FASA, study's senior author, professor of anesthesiology, CU Anschutz School of Medicine

Eckle's previous studies using rodent models have shown that bright light can strengthen the endothelium or lining of the blood vessels. The protection comes from a protein called PER2 which works with fellow protein HIF1A to boost levels of yet another protein ANGPTL4, a key player in vascular health.

In this study, the researchers gave some patients having routine spine surgery intense light therapy for 30 minutes at sunrise for five days. The light increased ANGPTL4 levels and lowered troponin levels. Those who didn't receive the therapy saw troponin levels increase.

Eckle said bright light therapy increases the circadian rhythm amplitude and protects the heart before and after myocardial injury. The protection relies on the presence of the PER2 protein, but Eckle's team found that ANGPTL4 protein therapy can protect the heart even when PER2 is missing.

"This ANGPTL4 protein therapy could be a promising strategy to reduce myocardial injury to patients one day," Eckle said. "We have started using intense light therapy in patients and have seen similar pathways are activated in humans as they are in animal models. A clinical trial will be necessary to understand the real impact of intense light therapy on Myocardial Injury in Noncardiac Surgery."

This study was funded by an R56 from the National Heart, Lung and Blood Institute.