Principal Findings:

Mean baseline ejection fraction was 29%, and 87% were treated with angiotensin-converting enzyme inhibitors. An average of 215 million cells were injected, with cell viability of 96%. The mean time post-MI was six years.

The first six patients enrolled in the study did not have an implantable cardiac defibrillator (ICD), as this was initially an exclusion criterion. Among those six initial patients, three patients had an event, one ventricular tachycardia, one nonsustained ventricular tachycardia, and one death. As a result of these events, the study was modified to require ICD implantation as an inclusion criterion. Nine patients were subsequently enrolled with an ICD, five of whom had an event (one tachycardia, one nonsustained ventricular tachycardia, one nonsustained ventricular tachycardia/ventricular tachycardia, one arrhythmia, and one slow ventricular tachycardia).

There was no difference in change from baseline to 12 months in ejection fraction (34.4% at baseline vs. 36.6% at 12 months, p=0.26), end diastolic volume (238 ml vs. 219 ml), or end systolic volume (158 ml vs. 143 ml, p=0.56). Wall motion score index was lower at follow-up compared with baseline both at rest (3.04 vs. 2.75, p=0.049) and at low-dose dobutamine stress (2.77 vs. 2.46, p=0.07). Additionally, New York Heart Association class improved from 2.8 at baseline to 1.8 at one year.