[00:00.2]
Hello, I'm Dr Ahran Arnold at Imperial College London. I'm going to be discussing the EMORI-HCM trial of right ventricular pacing in obstructive hypertrophic cardiomyopathy. So there are several treatments for obstructive hypertrophic cardiomyopathy available. Some are interventional: surgery including removal of the tissue obstructing the outflow tract, or ablating it using ethanol or other ablation techniques.

[00:23.5]
Or there are less invasive techniques which are mainly medications. The mainstay have been beta blockers and calcium channel blockers, but more rarely use disopyramide. And most recently we have the landscape changing drugs of the myosin inhibitors, including mavacamten and aficamten.

[00:40.5]
So EMORI-HCM is a blinded, randomised, crossover trial. So patients who have obstructive hypertrophic cardiomyopathy who already have a device in situ to allow pacing of the ventricle - the right ventricle specifically in this study - were allocated to either undergo a period of pacing for 3 months, then without pacing for 3 months, or randomly allocated to having no pacing for 3 months and then pacing for 3 months.

[01:03.9]
So they would all receive both treatments, either backup pacing i.e. no pacing, or continuous pacing. And the way the pacing was delivered was at optimal atrioventricular delay using a high precision haemodynamic algorithm. The most important finding was that the primary endpoint of Kansas City Cardiomyopathy Questionnaire clinical summary score was increased by continuous pacing at optimal atrioventricular delay compared to backup pacing by 4.5 points.

[01:30.9]
The standard of minimum clinically important difference is often benchmarked around 5 points. But important differences can be seen in this 4 to 5 point range. So the great thing about our trial in my opinion is that these are patients who already have the device implanted. So many, many patients already have a device implanted in a hypertrophic cardiomyopathy, in particular for defibrillator indications.

[01:52.9]
But they'll often be set to have only backup pacing because they don't need pacing for bradycardia reasons. What our trial shows is that if you get the atrial ventricular delay correct, you can simply turn on pacing in these patients. So it's a widely applicable therapy for patients who already have a device implanted.

[02:09.0]
Now, for patients who don't already have the device, there is a much bigger decision to be made because implanting a device just for the purposes of reducing the outflow tract gradient, improving symptoms in obstructive HCM, carries a risk of device implantation and the burden of ongoing follow-up, and that's the subject of ongoing research.

[02:26.1]
The key takeaway message for me from our trial, EMORI-HCM, is that pacing, simply activating pacing in a patient who already has a device in situ for obstructive HCM, can improve symptoms more than half the extent than the most expensive myosin inhibitors cheap, at the cost of just turning their device on.

[02:46.1]
So we think this is a highly cost effective therapy for patients. We're not saying at all, of course, that they should not be offered myosin inhibition, but the combination of the two does need to be studied. our findings are very important and we've shown a clear symptomatic benefit and exercise benefit for these patients.

[03:01.3]
However, none of the patients in our trial were taking myosin inhibitors. Now, both right ventricular pacing and myosin inhibitors can reduce ejection fraction and reduce ventricular performance. So we think it's very important that another trial is now run to combine the two therapies to see if we can maximise the effect without endangering ventricular function.

[03:20.2]
And we hope to look into a study like that shortly.