Novel adjunctive treatments of myocardial infarction

Abstract

Myocardial infarction is a major cause of death and disability worldwide and myocardial infarct size is a major determinant of prognosis. Early and successful restoration of myocardial reperfusion following an ischemic event is the most effective strategy to reduce final infarct size and improve clinical outcome, but reperfusion may induce further myocardial damage itself. Development of adjunctive therapies to limit myocardial reperfusion injury beyond opening of the coronary artery gains increasing attention. A vast number of experimental studies have shown cardioprotective effects of ischemic and pharmacological conditioning, but despite decades of research, the translation into clinical effects has been challenging. Recently published clinical studies, however, prompt optimism as novel techniques allow for improved clinical applicability. Cyclosporine A, the GLP-1 analogue exenatide and rapid cooling by endovascular infusion of cold saline all reduce infarct size and may confer clinical benefit for patients admitted with acute myocardial infarcts. Equally promising, three follow-up studies of the effect of remote ischemic conditioning (RIC) show clinical prognostic benefit in patients undergoing coronary surgery and percutaneous coronary intervention. The discovery that RIC can be performed noninvasively using a blood pressure cuff on the upper arm to induce brief episodes of limb ischemia and reperfusion has facilitated the translation of RIC into the clinical arena. This review focus on novel advances in adjunctive therapies in relation to acute and elective coronary procedures.

Keywords: Myocardial infarction, Primary percutaneous intervention, Coronary artery by-pass graft, Ischemia-reperfusion injury, Ischemic preconditioning, Remote ischemic conditioning, Cyclosporine, Cooling, Exenatide

Core tip: Patients with ischemic heart disease have a high risk of developing myocardial infarction, which is associated with considerable morbidity and mortality. Limiting the detrimental consequences of myocardial infarction is a major focus of cardiovascular research. Recent clinical studies suggest that novel adjunctive therapy with pharmacological and ischemic conditioning reduce ischemia-reperfusion injury in patients during coronary procedures. In three independent randomized trials, remote ischemic conditioning (RIC) improves clinical outcome in patients undergoing acute or elective percutaneous intervention or coronary artery by-pass surgery. RIC can be performed safely and non-invasively by intermittent inflation of a blood-pressure cuff on the upper arm and is easily applicable in most clinical settings.