Introduction: Ventricular rhythm disturbances have been one of the major concerns in the field of cell therapy in patients with chronic heart failure potentially limiting the long-term impact of this treatment modality.
Hypothesis: We sought to investigate the effects of transendocardial CD34+ cell therapy on the burden of ventricular arrhythmias in patients with chronic heart failure and reduced left ventricular ejection fraction (HFrEF).
Methods: We performed registry data analysis of patients with HFrEF and implanted ICD/CRT devices who were treated with transendocardial CD 34+ cell therapy at our center between years 2006 and 2016. Device records were reviewed and the number and type of ventricular rhythm disturbances one year prior to and one year after cell therapy were analyzed. Patients without ICD/CRT and patients with heart failure with preserved ejection fraction were excluded from the study. On electromechanical maps myocardial scar was defined as unipolar voltage (UV) < 8.3mV and linear local shortening (LLS) < 6%. Device activation was defined as ATP or shock.
Results: Of 209 patients in the registry 48 met inclusion criteria. The mean age of the patients was 52±10 years and 88% were male. Nonischemic and ischemic dilated cardiomyopathy (DCM) were present in 55% and 45% of patients. The average serum creatinine was 91±26μmol/L, serum bilirubine 18±9 μmol/L, NT-proBNP 2027±2486 pg/mL, LVEF 27±9% and 6' walk test 442±123 m. The average scar burden in patients with nonischemic and ischemic DCM was 58±15% and 51±25% respectively (P=0.48). No significant difference in the burden of ventricular arrhytmias was observed before and after cell therapy (48±49% vs. 44±48%; P=0.68). Monomorphic ventricular tachycardia was the predominant arrhytmia before and after cell therapy (98% vs. 100%). Device activation occured in 20% and 29% of patients before and after cell therapy respectively (P=0.23) with ATP being the predominant type of activation mode.
Conclusions: CD34+ cell therapy does not apper to increase the risk on ventricular arrhytmias in chronic heart failure patients. Futher studies are needed to investigate whether targeted use of cell therapy could be implemented in an aim to decrease the burden of ventricular arrhytmias in this patient cohort.