Upgrading to biventricular pacing/defibrillation systems in right ventricular paced congestive heart failure patients: prospective assessment of procedural parameters and response rate.

AIMS: Cardiac resynchronization therapy (CRT) is indicated in patients with heart failure and bundle branch block. It is less clear whether this includes patients with pre-existing right ventricular pacemaker/defibrillator systems, particularly with respect to implantation success and clinical benefit. METHODS AND
RESULTS: In consecutive patients scheduled for CRT, we prospectively compared implantation success, procedural parameters, and clinical response in 'de novo' vs. upgrade procedures of previously implanted right ventricular systems. CRT implantation was attempted in 79 consecutive patients (64 +/- 11 years, 63 male, 38 ischaemic, 41 non-ischaemic cardiomyopathy). De novo implantation was performed in 61 patients, upgrade procedures in 18 patients. Implant success (92 vs. 94%, P = 1.00), procedure duration (153 +/- 43 vs. 164 +/- 65 min, P = 0.51), fluoroscopy time (25 +/- 18 vs. 32 +/- 22 min, P = 0.18) or dose (40 +/- 31 vs. 52 +/- 49 Gy/cm(2), P = 0.35), and response rate (66 vs. 59%, P = 0.5) were comparable for both groups.
CONCLUSION: Procedural aspects, implantation success, and clinical response to CRT were comparable for patients undergoing de-novo vs. upgrade procedures. Accordingly, patient selection for upgrading should be the same as for new CRT implantation.