Effect of Personalized Accelerated Pacing in Symptomatic Patients With Non-Obstructive Hypertrophic Cardiomyopathy

Effect of Personalized Accelerated Pacing in Symptomatic Patients With Non-Obstructive Hypertrophic Cardiomyopathy

This will be a two-arm investigator-initiated randomized controlled study of patients with nHCM and LV ejection fraction ≥50% and NYHA II-III symptoms, normal intrinsic conduction system and pre-existing suitable dual-chamber implantable cardioverter defibrillators (ICD) systems. Patients will be randomly assigned to either personalized accelerated pacing (using the myPACE+ algorithm with mono-fractional exponent) or usual care groups. At baseline and after 3 months of pacing all patients will undergo a CPET, echocardiogram, blood work for NT-proBNP levels and complete the KCCQ-OSS and HCMSQ, questionnaires.

The investigator team hypothesizes that personalized accelerated pacing will be safe and improve symptoms and heart-failure related quality of life, physical activity, pVO2, biomarkers (i.e. NT-proBNP), diastolic parameters and cardiac structure.

This will be a two-arm investigator-initiated randomized controlled study of patients with nHCM and LV ejection fraction≥50% and NYHA II-III symptoms, normal intrinsic conduction system and pre-existing suitable dual-chamber implantable cardioverter defibrillators (ICD) systems. Patients will be randomly assigned to either personalized accelerated pacing (using the myPACE+ algorithm with mono-fractional exponent) or usual care groups. At baseline and after 3 months of pacing all patients will undergo a CPET, echocardiogram, blood work for NT-proBNP levels and complete the KCCQ-OSS and HCMSQ, questionnaires.

The investigator team hypothesizes that personalized accelerated pacing will be safe and improve symptoms and heart-failure related quality of life, physical activity, pVO2, biomarkers (i.e. NT-proBNP), diastolic parameters and cardiac structure. An interim data safety analysis will be conducted.

Inclusion Criteria:

• Non obstructive HCM: Left Ventricular Outflow Tract (LVOT) gradient <30mmHg at rest and with provocation
• Left ventricular ejection fraction (LVEF) ≥50%
• New York Heart Association (NYHA II-III) symptoms
• Normal intrinsic conduction system
• Suitable dual-chamber implantable cardioverter defibrillators (ICD) system

Exclusion Criteria:

• Pregnancy
• LVEF <50%
• LVOT gradient > 30mmHg at rest or with provocation
• Prolonged PR > 250ms
• Baseline RV-pacing burden of > 1% more than moderate valvular stenosis or regurgitation
• Aortic valve replacement in the past one year
• Significant primary pulmonary disease on home oxygen
• Uncontrolled hypertension as defined by BP >160/100 mmHg on two measurements ≥15 minutes apart