Vanhentenrijk S; Vascular and Thoracic Institute, Cleveland Clinic,
Cleveland, Ohio. USA
Chaikijurajai T; Engelman T; Grodin JL;et al

American Journal of Cardiology. 272:103-109, 2026 Aug 01.

Hemodynamic gain index (HGI) is a novel, simple parameter calculated from
resting and peak systolic blood pressure and heart rate (HR) during
exercise, however, its prognostic value in patients with hypertrophic
cardiomyopathy (HCM) is unknown. We investigate the prognostic value of
alternative nonmetabolic exercise testing parameters in a contemporary HCM
cohort. HGI was calculated from systolic blood pressure at rest and peak
/HR data from consecutive HCM patients who underwent cardiopulmonary
exercise testing for symptom evaluation. Multivariable Cox regression
analysis was performed with the primary outcome of all-cause mortality
and/or heart transplantation. Logistic regression models were used for HGI
to predict the need for future myectomy or alcohol septal ablation. In our
cohort of 905 patients with HCM, HGI correlated well with circulatory
power (CP, r = 0.71, p <0.001) and peak VO2 (r = 0.64, p <0.001). HGI
(Area Under Curve (AUC) 0.87, 95% CI 0.81-0.92) demonstrated comparable
accuracies to CP (AUC 0.88, 95% CI 0.83-0.92) and peak VO2 (AUC 0.81, 95%
CI 0.75-0.87) in predicting transplant-free survival. Higher HGI was
independently associated with a lower risk of primary endpoint (adjusted
HR 0.25, 95% CI 0.15-0.42, p <0.001), all-cause mortality (adjusted HR
0.31,95% CI 0.17-0.56, p <0.001), and was associated with lower risk for
future myectomy or alcohol septal ablation (OR 0.78, 95% CI 0.67-0.91, p =
0.002). HGI may serve as an independent predictor for adverse outcomes in
patients with HCM with comparable prognostic value to peak VO2 and CP. In
addition, HGI may identify those who would likely need myectomy or alcohol
septal ablation, independent of pVO2 evaluation.