Electromechanically Optimized Right Ventricular Pacing for Obstructive Hypertrophic Cardiomyopathy: The EMORI-HCM...

Area of Science:

• Cardiology
• Medical Devices
• Clinical Trials

Background:

• Obstructive hypertrophic cardiomyopathy (oHCM) patients often have pacemakers, but right ventricular pacing (RVP) has variable effects on cardiac output and left ventricular outflow tract gradient (LVOTg).
• The net benefit of RVP in oHCM is not fully understood, necessitating further investigation into optimization strategies.

Purpose of the Study:

• To determine if electromechanically optimized atrio-ventricular delay (AVD) can yield a net symptomatic benefit from RVP in patients with symptomatic oHCM.
• To evaluate the impact of AVD-optimized RVP on symptoms, exercise capacity, and LVOTg in oHCM patients.

Main Methods:

• A multi-center, blinded, randomized, cross-over trial (EMORI-HCM) involving 60 patients with symptomatic oHCM and significant LVOTg.
• Patients with dual-chamber devices were randomized to AVD-optimized RVP or back-up only RVP for three months each, with AVD optimized via a precise protocol.
• Primary outcome was symptom improvement (KCCQ-CSS); secondary outcomes included daily symptoms, patient preference, EQ-5D, exercise capacity, and LVOTg.

Main Results:

• AVD-optimized RVP significantly improved KCCQ-CSS scores and daily symptom scores compared to back-up pacing.
• Patients experienced improved exercise capacity and a reduction in LVOTg with AVD-optimized RVP.
• No significant effect was observed on BNP levels, and ejection fraction was preserved.

Conclusions:

• Electromechanically optimized AVD for RVP in oHCM patients leads to improved symptoms and enhanced exercise capacity.
• This optimization strategy offers a potential therapeutic benefit for managing symptomatic oHCM in patients with pacing devices.