Author Affiliations: Minneapolis Heart Institute Foundation at Abbott Northwestern Hospital, Minneapolis, Minnesota (Drs Traverse and Henry) (Jay.Traverse@allina.com); and University of Florida College of Medicine, Gainesville (Dr Pepine), for the Cardiovascular Cell Therapy Research Network.
In Reply: We support Dr Ly's comments on the importance of patient selection in these trials. We elected to include patients with large infarcts from lesions in non–left anterior descending coronary arteries to facilitate enrollment, but only 5 patients had non–anterior MIs. Their inclusion did not appear to influence outcomes because the results were similar when analyzed without these patients. We have no evidence suggesting our patients had other forms of cardiomyopathy contributing to the reduced LVEF on qualifying echocardiogram (mean [SD], 36.4% [6.5%]) within 48 hours of their PCI. When measured at the time of the intracoronary infusion several weeks later, LVEF had increased (mean [SD], 44.3% [8.4%]) likely due to resolution of myocardial stunning. Still, it remained below the baseline median of 48.9% seen in the Reinfusion of Enriched Progenitor Cells and Infarct Remodeling in Acute Myocardial Infarction (REPAIR-AMI) study in which the greatest benefit of BMCs on LVEF recovery was observed.1 We agree that patients with persistent LV dysfunction after MI (LVEF <35%) constitute an important target for future studies that should include new cell types and delivery methods such as intramyocardial or transcoronary delivery. We are currently performing more detailed MRI analyses to address the extent of infarct transmurality and microvascular obstruction that may also influence outcomes.
Traverse JH, Henry TD, Pepine CJ. Intracoronary Bone Marrow Mononuclear Cells After Myocardial Infarction—Reply. JAMA. 2012;307(10):1022-1024. doi:10.1001/jama.2012.280