Response rate in cardiac resynchronization therapy patients implanted with a left ventricular quadripolar lead and the MultiPoint™ pacing feature early activated. QUARTO III

Background: Although cardiac resynchronization therapy (CRT) is beneficial in most heart failure patients, up to 40% do not respond to CRT. It has been suggested that multipoint left ventricle pacing (MPP) would increase the response rate. Aim: To assess the CRT response rate at 6 months in patients implanted with a CRT device with the MPP feature activated early after the implant. Methods: This was a multicentre, prospective, open-label and non-randomized study. The primary endpoint was response to biventricular pacing defined as > 15% relative reduction in left ventricular end-systolic volume (LVESV) comparing echocardiography measurements performed at baseline and 6 months by a core laboratory. Among secondary endpoints the combined endpoint of mortality or all-cause hospitalizations was evaluated. Primary study endpoint and clinical outcomes were compared to a Quarto II control cohort. Results: Totally, 105 patients were included. The response rate was 64.6% (97.5% lower confidence bound 53%). Mean relative reduction in LVESV was 25.3%, and mean absolute increase in LVEF was 9.4%. The subjects with device programmed using anatomical approach showed a trend towards higher responder rate than those using the electrical approach (72% vs. 61.1%, p = 0.32). Finally, the combined incidence of mortality and or all-cause hospitalizations at 6 month was 12.4%. Conclusions: Early activation of MPP was not associated to an advantage increasing echocardiography responders to CRT at 6 months of follow-up. Nevertheless, patients programmed using widest pacing cathodes had a numerically higher responder rate. Finally, early activation of MPP was associated to a low incidence of clinical endpoints at 6 months of follow-up.

Automated summary

This study aimed to evaluate the response rate of cardiac resynchronization therapy (CRT) in patients implanted with a CRT device with multipoint left ventricle pacing (MPP) activated. The results showed a response rate of 64.6% at 6 months, with a decrease in left ventricular end-systolic volume (LVESV) of 25.3% and an increase in left ventricular ejection fraction (LVEF) of 9.4%. Early activation of MPP was associated with a low incidence of clinical endpoints at 6 months.