I'm Professor Christophe Leclercq from Rennes University in France, and I will discuss the result of the MORE- CRT multipoint pacing trial.

Could you tell us about the unique features of the MPP device?

The MPP device is a pacemaker or defibrillator which provides what we call biventricular pacing. We have a lead in the right ventricle, a lead in the right atrium in case of sinus rhythm and lead into the coronary sinus. Classically, we have only one pacing site in the coronary sinus to pace the left ventricle. With MPP we have two pacing sites in the same vein, so this provides a better left ventricular activation.

What is the importance behind the MORE-CRT MPP trial?

The MORE-CRT MPP trial was designed to assess if mulitpoint pacing can improve the rate of conversion from non-responder to responder patients in a population who did not respond to conventional CRT, I mean biventricular pacing. As you know, about 40% of the patients do not respond on CRT using biventricular pacing. And so we want to assess if to provide MPP pacing may convert this patient to the responder population.

What was the study design and patient population?

So at the end of the trial we included about 4,000 patients and they were paced with biventricular pacing during six months. At six months, we performed a new echocardiography and we split the population in two groups: the responder patient, we had a decrease in left ventricular and systolic volume more than 15%, and the non-responder patient, with a decrease in left ventricular and systolic volume less than 15%. And we kept only the non-responders, and the responders were randomized in two groups: MPP or biventricular pacing for the next six months. And then we do another echo to see if the proportion of patients who became responders.

What were the key findings and how can they be used to identify patients who would benefit most from CRT with MPP?

The key finding of the trial is that MPP does not improve the conversion rate as compared to biventricular pacing based on an echo criteria. But as we know, there is some discrepancy between echo response and clinical response.

So this substudy was designed to assess if the patient who are not responder with bivipacing can improve significantly in terms of reduction of heart failure hospitalization or death. The main result was that we have a significant reduction with MPP by 37% in the combined endpoint, mainly driven by the decrease in heart failure hospitalization for heart failure, but no difference in mortality.

What are the take-home messages for practice?

Key take-home message is that in patients who are non-responders, you have to do everything you can to make them responders. It could be, of course, improving drug therapy but also to tune the device as much as possible and MPP one of the solutions.

What we found interestingly in this trial is that, for example, ischemic patients had a more important benefit with MPP as compared to non-ischemic, but also patient with wide QRS and patient with a very long intraventricular delay between the right ventricle, the left ventricle. So I think this very important message. Don't give up when you have a non responder patient.

What further research is needed in this area?

I think that in this field, we have to keep on working about new algorithms to provide a better synchronisation. And as you know, there is a very important attraction about the new pacing mode, what we call conduction system pacing, by pacing the left bundle branch block area. And this could be also a very important source of research by comparing biventricular pacing versus CSP. Today, we don't have a strong evidence for CSP, but I think we have to move forward for that.