Bone-marrow-derived cell transfer after ST-elevation myocardial infarction: lessons from the BOOST trial.

Emerging evidence suggests that bone-marrow-derived stem and progenitor cells can be used to improve cardiac function after acute myocardial infarction. We tested this concept in the randomized, controlled, BOOST (bone marrow transfer to enhance ST-elevation infarct regeneration) clinical trial. Following successful percutaneous coronary intervention for acute ST-elevation myocardial infarction, patients received an intracoronary transfer of autologous bone marrow cells (BMCs). After 6 months, global left ventricular ejection fraction, as determined by magnetic resonance imaging, was significantly improved in the BMC-treated group compared with the control group. BMC transfer enhanced left ventricular systolic function, primarily in myocardial segments adjacent to the infarcted area, and also had a positive effect on diastolic function. BMC transfer did not increase the risk of adverse clinical events and did not promote in-stent re-stenosis or proarrhythmic effects. In principle, the effects of BMC transfer on ejection fraction were sustained at 18-month follow-up. Notably, radioactive labeling of BMCs and positron emission tomography showed that these beneficial effects are achieved with limited cardiac homing of BMCs after intracoronary application. Taken together, our studies indicate that intracoronary transfer of autologous BMCs is a safe, promising, and novel approach to further improving systolic function in patients with successful reperfusion after acute myocardial infarction.