Mohal, Jagdeep S;
Whinnett, Zachary I;
Mohiddin, Saidi A;
Malcolmson, James;
Elliott, Perry;
Ormerod, Julian OM;
Prasad, Sanjay;
... Arnold, Ahran D; + view all
(2025)
Electromechanically Optimized Right Ventricular Pacing for Obstructive Hypertrophic Cardiomyopathy (EMORI-HCM).
JACC
10.1016/j.jacc.2025.08.050.
(In press).
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Abstract
Background Many patients with symptomatic obstructive hypertrophic cardiomyopathy (oHCM) have devices capable of right ventricular pacing (RVP). Although pacing can reduce left ventricular outflow tract gradient (LVOTg), it can also reduce cardiac output, so its net effect is variable. Objective We tested whether electromechanical optimisation of the programmed atrio-ventricular delay (AVD) allows RVP to achieve a net benefit on symptoms. Methods EMORI-HCM is a multi-center, blinded, randomized, cross-over trial of AVD-optimized RVP in patients with symptomatic oHCM with resting or provoked gradient at least 30mmHg. Patients with existing dual-chamber devices were randomized to either three months of continuous AVD-optimized RVP (intervention) followed by three months of back-up only RVP (control), or vice versa. AVD was optimized using a high-precision multiple-alternation protocol assessing acute change in beat-by-beat blood pressure whilst varying AVD. The primary outcome was symptoms measured by the Kansas City Cardiomyopathy Questionnaire-Clinical Summary Score (KCCQ-CSS). Secondary outcomes include patient-reported daily symptom data collected using a dedicated smartphone application (ORBITA-app), dichotomous patient preference, EQ-5D, exercise capacity and LVOTg. Patients were blinded to treatment allocation. Symptom assessments were self-administered. Outcome measures were recorded at baseline, crossover and completion. Analysis was by Bayesian ordinal mixed modelling. This study is registered with ClinicalTrials.gov (NCT05257772). Results Between October 2021 and October 2024, 117 screened patients met the inclusion criteria, of whom 60 were randomized. AVD-optimized RVP improved KCCQ-CSS (+4·505, 95% CrI 1·307 to 8·090, probability of benefit (Prbenefit)=0·997) and daily symptom scores (odds ratio 1.29, 95% CrI 0.978 to 1.676, Prbenefit=0.969) compared to back-up only pacing. AVD-optimized RVP improved exercise capacity (+1.048ml/kg/min, 95% CrI 0.065 to 2.043, Prbenefit=0.984) and LVOTg (−7.327mmHg, 95% CrI −13.526 to −1.074, Prbenefit=0.010). It had no effect on BNP (Prbenefit=0.893) and ejection fraction was preserved (Prbenefit=0.409). Conclusion In patients with oHCM, RVP delivered at electromechanically optimized AVD improves symptoms and exercise capacity.
| Type: | Article |
|---|---|
| Title: | Electromechanically Optimized Right Ventricular Pacing for Obstructive Hypertrophic Cardiomyopathy (EMORI-HCM) |
| DOI: | 10.1016/j.jacc.2025.08.050 |
| Publisher version: | https://doi.org/10.1016/j.jacc.2025.08.050 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Hypertrophic cardiomyopathy, Pacemaker, Atrioventricular delay |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Cardiovascular Science UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Population Health Sciences > Institute of Cardiovascular Science > Clinical Science |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10213317 |
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