A recent study, led by Professor Gerd Heusch of the Institute for Pathophysiology, and Dr Matthias Thielmann, of the Department of Thoracic and Cardiovascular Surgery, both based at the University School of Medicine Essen, Germany, analyzed the effects of a procedure known as remote ischaemic preconditioning on patients undergoing coronary artery bypass graft surgery.

Remote ischaemic preconditioning is the process of briefly cutting off, and then restoring, the blood supply to an area of the body remote from the heart, like the arm. Although it has been known for the last 20 years that the process reduces injury to the heart muscle, this is the first randomized control trial to determine whether or not it impacts long term survival after bypass surgery, in addition to its effects on other clinical outcomes, such as heart attack and stroke.

After screening nearly 3000 patients from the West German Heart Centre, researchers chose 162 patients scheduled for heart bypass surgery for the intervention group. After the induction of anesthesia before surgery, the patients had their blood pressure restricted for 5 minutes by having a blood pressure cuff inflated on their upper arm, followed by 5 minutes to restore blood flow with the cuff deflated. This process was repeated 3 times before surgery. More than 160 patients were chosen for the control group and did not undergo the process just before surgery.

After surgery, researchers measured the patients’ blood for concentrations of a substance called troponin I, a biomarker protein that indicates damage to the heart muscle. Researchers also followed up with the patients for up to 4 years following the surgery to determine what long term effects the remote preconditioning had on their health.

The research showed a clear and immediate benefit from the process, with patients having an average of 17 percent less troponin I concentration than those in the control group 72 hours after surgery. Long term data was also encouraging, showing that one year after surgery patients in the study group were 73 percent less likely to have died from any cause and 86 percent less likely to have died from heart attack or stroke, in comparison to the control group.

According to Professor Heusch, “The results of our study are very encouraging that remote ischaemic preconditioning not only reduces heart muscle injury but also improves long-term health outcomes for heart bypass patients, and we hope that these benefits will be confirmed in larger prospective studies which are currently taking place.”

“The beauty of remote ischaemic preconditioning is that it is non-invasive, simple, cheap, and safe,” adds Dr Thielmann. “This procedure could be a promising and simple strategy to protect patients’ heart muscle during surgery and hopefully improve health outcomes after surgery.”