Pacemaker Versus Defibrillator Therapy in Patients Eligible for Cardiac Resynchronisation Therapy: Evidence from the German Device Registry.

Background

According to current guidelines, cardiac resynchronisation therapy (CRT) is recommended in patients with significantly impaired left ventricular systolic function and left bundle branch block. However, the decision between pacemaker (CRT-P) and defibrillator (CRT-D) in patients eligible for CRT remains a matter of debate. Register data have shown a higher all-cause mortality in CRT-P in comparison to patients with a CRT-D. Here, we investigated clinical determinants of the selection of CRT-P vs. CRT-D and clinical outcome in large registry data from a multi-centre 'real-life' registry on patients with CRT defibrillator or pacemaker therapy.

Methods

The German Device Registry (DEVICE) is a nationwide, prospective registry with one-year follow-up investigating 5451 patients receiving device implantations in 50 German centres. The present analysis of DEVICE focused on all patients from the register receiving cardiac resynchronization therapy.

Results

Out of 1603 patients receiving cardiac resynchronisation therapy, 1536 (95.8%) received a CRT defibrillator system and 67 (4.2%) a CRT pacemaker system. Patients in the CRT-P group had a significantly better left ventricular systolic function compared to the CRT-D group (median 35% vs. 25%), and significantly less often had a history of myocardial infarction (9.0% vs. 25.2%). A preexisting pacemaker and a history of stroke/peripheral embolism were identified as determinants for the selection of CRT-P vs. CRT-D. Overall mortality after one-year follow-up was 8.0%. Patients with ischemic cardiomyopathy receiving CRT-P therapy had a higher one-year mortality than patients receiving CRT-D (21.2% vs. 8.9%, p = 0.020). On the other hand, patients with non-ischemic cardiomyopathy did not display differences between these two treatment groups (CRT-P 8.1%, CRT-D 6.6%, p = 0.72).

Conclusions

Data from the German device registry show that most patients receiving cardiac synchronization therapy have an implanted CRT-D system. In comparison to patients with CRT-D, those with CRT-P more often had a non-ischemic cardiomyopathy and a preexisting pacemaker system. The outcomes between these two treatment groups were different as regards ischemic cardiomyopathy only.