Background: Despite several new advances in the treatment of end-stage congestive heart failure (CHF) the number of patients moving onto the heart transplant list continues to rise. Recently, cardiac resynchronization therapy (CRT) has become a Food and Drug Administration (FDA)-approved therapy for advanced CHF. Currently, there are no available data on CRT in cardiac transplant candidates.
Methods: To determine the effects of CRT on potential transplant candidates we retrospectively reviewed patients (n = 34) enrolled in resynchronization trials at our center who met accepted criteria for transplantation. Ventricular function, oxygen uptake and New York Heart Association (NYHA) class were compared at baseline and after 6 months of active therapy for each patient.
Results: CRT reduced QRS duration from 178 +/- 29 to 143 +/- 17 msec (p < 0.0001) and NYHA class from 3.1 +/- 0.3 to 1.8 +/- 0.7 (p < 0.0001). Ejection fraction (EF) increased from 18.4 +/- 5.1 to 25.1 +/- 8.4% (p < 0.0001) and maximum VO(2) increased from 11.9 +/- 1.8 to 15.3 +/- 3 ml/kg/min (p < 0.0001). Only 2 of the initial 34 patients still met the criteria for transplantation at 6 months.
Conclusions: CRT improves ventricular function, oxygen uptake and NYHA class in ambulatory patients who have a QRS of >130 msec and might be considered candidates for cardiac transplantation. Transplantation can be prevented or deferred in the majority of patients. Outpatients with chronic CHF and a widened QRS should be evaluated for CRT before being listed for cardiac transplantation.