Cardiac resynchronization therapy guided by multimodality cardiac imaging

Abstract

Aims: Up to 30-45% of implanted patients are non-responders to CRT. We evaluated the role of a 'CRT team' using cardiac magnetic resonance (CMR) and longitudinal myocardial strain to identify the target area defined as the most delayed and viable region for LV pacing.

Methods and results: A total of 100 heart failure patients candidates for CRT divided into two groups were enrolled. Group 1 consisted of 50 consecutive patients scheduled for CRT and prospectively included. Group 2 (control) consisted of 50 patients with a CRT device implanted according to standard clinical practice and matched for age, sex, and LVEF with group 1. Patients were evaluated at baseline and at 6-month follow-up. In group 1, patients underwent two-dimensional speckle-tracking assessment of longitudinal myocardial strain and CMR imaging to identify the target area for LV lead pacing. A positive response to CRT was defined as a reduction of ≥15% of the LV end-systolic volume at 6-month follow-up. A total of 39 (78%) patients of group 1 were classified as responders to CRT whilst in group 2, only 28 (56%) were responders (P = 0.019). The 'CRT team' identified as target for LV pacing the lateral area in 30 (60%) patients, and the anterolateral or posterolateral areas in 12 (24%) patients. In 8 (16%) patients, the target was far from the lateral area, in the anterior or posterior areas. The patients with concordant position exhibited the highest positive response (93.1%) to CRT.

Conclusions: Multimodality cardiac imaging as a guide for CRT implantation is useful to increase response rate.

Keywords: Cardiac resynchronization therapy; Heart failure; Left ventricular lead position.