Skeletal myoblast transplantation in ischemic heart failure -: Long-term follow-up of the first phase I cohort of patients

Background-Skeletal myoblast (SM) transplantation (Tx) in a post-myocardial infarction (MI) scar experimentally improves left ventricular (LV) ejection fraction (EF). Short-term follow-up (FU) studies have suggested that a similar benefit could clinically occur despite an increased risk of LV arrhythmias. Methods and Results-We report the long-term FU of the first worldwide cohort of grafted patients (n=9, 61.8 +/- 11.6 years, previous MI, EF <= 35%) operated on (autologous SM Tx and bypass surgery) in 2000 to 2001 and evaluated before Tx, at 1 month (M1) and at a median FU of 52 (18 to 58) months after Tx (37 patient-years). NYHA class improved from 2.5 +/- 0.5 to 1.8 +/- 0.4 at M1 (P=0.004 versus baseline) and 1.7 +/- 0.5 at FU (P=not significant versus M1; P=0.0007 versus baseline). EF increased from 24.3 +/- 4% to 31 +/- 4.1% at M1 (+28%, P=0.001 versus baseline) and remained stable thereafter (28.7 +/- 8.1%, + 18% versus baseline). There were 5 hospitalizations for heart failure in 3 patients at 28.6 +/- 9.9 months, allowing implant in 2 patients with a resynchronization pacemaker. An automatic cardiac defibrillator (ACD) was implanted in 5 patients for nonsustained (n=1) or sustained (n=4) ventricular tachycardia at 12.2 +/- 18.6 (1 to 45) months. Despite a beta-blocker/amiodarone combination therapy, there were 14 appropriate shocks for 3 arrhythmic storms in 3 patients at 6, 7, and 18 months after ACD implantation. Conclusions-In this cohort of severe heart failure patients both clinical status and EF stably improve over time with a strikingly low incidence of hospitalizations for heart failure (0.13/patient-years) and the arrhythmic risk can be controlled by medical therapy and/or on-request ACD implantation.