Aims: To evaluate the association between an apical vs. non-apical right ventricular lead position (RV-LP) and clinical outcome in a large nationwide cohort of patients treated with cardiac resynchronization therapy (CRT).

Methods and results: We included consecutive Danish patients receiving a CRT device from 2008 to 2012, identified from the Danish Pacemaker and ICD Register. Endpoints were mortality, mortality or hospitalization for heart failure (HF), and clinical response (improvement ≥1 New York Heart Association class at follow-up). Subgroup analysis was made for ischaemic heart disease (IHD) and non-IHD. Cox and logistic regression analyses were used to calculate adjusted HR (aHR) and adjusted odds ratios with 95% confidence intervals (CI). A total of 2883 patients received a CRT device during the period. We excluded 301 patients that did not meet standard CRT indication. In 2391 (93%) of the remaining 2582 patients the RV-LP was defined as apical in 647 (27%) and non-apical in 1744 (73%). After mean 3.2 ± 2 years, 660 patients had died, 1275 patients were hospitalized for HF, and 1021 were responders. With a non-apical RV-LP the aHR for mortality was 0.93 (95% CI 0.0.79-1.10, P = 0.40) and the aHR for the combined endpoint of mortality or HF-hospitalization was 0.89 (95% CI 0.79-0.99, P = 0.03). These findings were significant only in patients with non-IHD. There was no association between clinical response and RV-LP.

Conclusion: A non-apical RV-LP is associated with lower risk of meeting the combined endpoint of mortality or hospitalization for HF in patients with CRT. In subgroup analysis, this association was present only in patients with non-IHD.