Characterization and Application of Novel Exercise Recovery Patterns That Reflect Cardiac Performance: A Substudy of...

Area of Science:

• Cardiology
• Exercise Physiology
• Heart Failure Research

Background:

• Post-exercise oxygen uptake recovery (VO2Rec) is prolonged in advanced heart failure.
• Easily derived VO2Rec measures are needed for clinical assessment.
• VO2Rec modifiability with cardiac function changes is key in obstructive hypertrophic cardiomyopathy (oHCM).

Purpose of the Study:

• Establish easily derived VO2Rec measures.
• Evaluate cardiospecificity and prognostic relevance of VO2Rec in dyspnea on exertion.
• Determine VO2Rec modifiability with cardiac function changes in oHCM patients treated with aficamten.

Main Methods:

• Utilized cardiopulmonary exercise testing with hemodynamic monitoring in a referral cohort (MGH-ExS).
• Assessed VO2Rec as time for VO2 to decline by 12.5% (VO2T12.5%), 25%, and 50% of peak VO2.
• Investigated longitudinal VO2Rec in the SEQUOIA-HCM trial of aficamten in oHCM patients.

Main Results:

• Longer VO2T12.5% in MGH-ExS patients correlated with elevated exercise pulmonary capillary wedge pressure to cardiac output slope.
• Each 15-second increase in VO2T12.5% predicted a 1.54-fold increased hazard for heart failure hospitalization and death.
• Aficamten treatment in SEQUOIA-HCM improved VO2T12.5% and correlated with reduced cardiac biomarkers and LVOT gradient.

Conclusions:

• VO2T12.5% is a novel, simple measure reflecting cardiac performance during exercise.
• VO2T12.5% predicts heart failure event-free survival.
• VO2T12.5% improvement with aficamten treatment highlights its utility in oHCM and suggests broader clinical applicability.