Abstract 687: Cardiac Imaging with Multi-Slice Computed Tomography and Echocardiography to Guide Left Ventricular Lead Placement in Resynchronization Therapy. The CAMERA Trial
Cardiac resynchronization (CRT) is associated with reverse ventricular remodeling and improved clinical outcomes, but is not successful in all patients. We looked at the feasibility of combined non-invasive imaging of the coronary veins and assessment of left ventricular dyssynchrony prior to pacemaker implantation and whether this combination would improve procedural success and patient outcome. Heart failure patients with standard indications for CRT were randomized to cardiac Multi-Detector CT (MDCT) plus Doppler echocardiographic assessment of left ventricular dyssynchrony versus conventional management prior to CRT. Co-registration of MDCT and tissue synchronization imaging data using a novel software program was performed and the results were used to optimize left ventricular lead placement for patients in the non-invasive imaging arm. 21 patients were enrolled with 9 patients randomized to the contemporary non-invasive imaging strategy and 12 patients randomized to the control group. MDCT correctly identified 19 of 24 (79%) coronary venous branches ≥ 2 mm in diameter when compared to invasive coronary venography. Patients in the non-invasive imaging group had a significant improvement in the 6 minute walk time on 6 month follow up (76.1 ± 48.4 meters vs 20.0 ± 64.8 meters, p = 0.04). Improvements in NYHA functional class and LV remodeling at 6 months were not significantly different in the non-invasive imaging and control arms. Left ventricular lead placement was successful in all patients, however more patients in the non-invasive imaging arm demonstrated LV lead placement in the most delayed or adjacent myocardial segment (8 of 9 vs 6 of 12, p = 0.09). Those patients with “optimal” lead placement showed a trend towards improved 6 minute walk times and improvement in left ventricular function 6 months after biventricular pacing. An imaging-guided strategy with coregistration of MDCT coronary venous anatomy and delayed myocardial segments by tissue Doppler echocardiography prior to CRT is feasible and may improve patient outcomes by facilitating optimal LV lead placement.