Early increase in myocardial perfusion after stem cell therapy in patients undergoing incomplete coronary artery bypass surgery.

Incomplete revascularization is associated with worse long-term outcomes. Autologous bone marrow cells (BMC) have recently been tested in patients with severe coronary artery disease. We tested the hypothesis that intramyocardial injection of autologous BMC increases myocardial perfusion in patients undergoing incomplete coronary artery bypass grafting (CABG). Twenty-one patients (19 men), 59 ± 7 years old, with limiting angina and multivessel coronary artery disease (CAD), not amenable to complete CABG were enrolled. BMC were obtained prior to surgery, and the lymphomonocytic fraction separated by density gradient centrifugation. During surgery, 5 mL containing 2.1 ± 1.3 × 108 BMC (CD34+ = 0.8 ± 0.3%) were injected in the ischemic non-revascularized myocardium. Myocardial perfusion was assessed by magnetic resonance imaging (MRI) at baseline and 1 month after surgery. The increase in myocardial perfusion was compared between patients with <50% (group A, n = 11) with that of patients with >50% (group B, n = 10) of target vessels (stenosis ≥ 70%) successfully bypassed. Injected myocardial segments included the inferior (n = 12), anterior (n = 7), and lateral (n = 2) walls. The number of treated vessels (2.3 ± 0.8) was significantly smaller than the number of target vessels (4.2 ± 1.0; P < 0.0001). One month after surgery, cardiac MRI showed a similar reduction (%) in the ischemic score of patients in group A (72.5 ± 3.2), compared to patients in group B (78.1 ± 3.2; P = .80). Intramyocardial injection of autologous BMC may help increase myocardial perfusion in patients undergoing incomplete CABG, even in those with fewer target vessels successfully treated. This strategy may be an adjunctive therapy for patients suffering from a more advanced (diffuse) CAD not amenable for complete direct revascularization.