New research has found that cutting off the blood supply immediately following a heart attack may protect the heart muscle from more extensive damage. The study, published in the February 27, 2010 issue of The Lancet, builds on earlier work, though the exact mechanisms of the treatment are still not well understood.
The researchers found that 30 days after heart attack, the patients who had undergone the treatment had about 30% more of their heart tissue preserved than controls.
The research team led by Hans Erik Botke followed 142 patients who were suffering from serious heart attacks and in the process of being brought to the hospital for treatment. The way the team interrupted blood flow was simple: while the patient was being transported to the hospital, a blood pressure cuff was inflated around the arm of a patient for five minutes and then relaxed. The process was repeated four times.
This process is called “induced ischemia,” which simply implies that a state of ischemia – or interrupted blood supply – is brought about intentionally. The researchers found that 30 days after heart attack, the patients who had undergone the treatment had about 30% more of their heart tissue preserved than controls.
Several earlier studies have investigated the method using animal subjects, but the current study is one of the first to look at it in humans. More clinical trials involving larger groups of participants will be needed to determine the method’s overall efficacy and in the long−term. The authors write that “[r]emote ischaemic conditioning before hospital admission increases myocardial salvage, and has a favourable safety profile. Our findings merit a larger trial to establish the effect of remote conditioning on clinical outcomes.”
Botke is affiliated with Aarhus University Hospital in Skejby, Denmark.