Cardiac resynchronization therapy non-responder to responder conversion rate in the more response to cardiac resynchronization therapy with MultiPoint Pacing (MORE-CRT MPP) study: results from Phase I.

AIMS: To assess the impact of MultiPoint™ Pacing (MPP)-programmed according to the physician's discretion-in non-responders to standard biventricular pacing after 6 months.

METHODS AND RESULTS: The study enrolled 1921 patients receiving a quadripolar cardiac resynchronization therapy (CRT) system capable of MPP™ therapy. A core laboratory assessed echocardiography at baseline and 6 months and defined volumetric non-response to biventricular pacing as <15% reduction in left ventricular end-systolic volume (LVESV). Clinical sites randomized patients classified as non-responders in a 1:1 ratio to receive MPP (236 patients) or continued biventricular pacing (231 patients) for an additional 6 months and evaluated rate of conversion to echocardiographic response. Baseline characteristics of both groups were comparable. No difference was observed in non-responder to responder conversion rate between MPP and biventricular pacing (31.8% and 33.8%, P = 0.72). In the MPP arm, 68 (29%) patients received MPP programmed with a wide LV electrode anatomical separation (≥30 mm) and shortest LV1-LV2 and LV2-RV timing delays (MPP-AS); 168 (71%) patients received MPP programmed with other settings (MPP-Other). MPP-AS elicited a significantly higher non-responder conversion rate compared to MPP-Other (45.6% vs. 26.2%, P = 0.006) and a trend in a higher conversion rate compared to biventricular pacing (45.6% vs. 33.8%, P = 0.10).

CONCLUSIONS: After 6 months, investigator-discretionary MPP programming did not significantly increase echocardiographic response compared to biventricular pacing in CRT non-responders.