Hemodynamic gain index in women: A validation study

Background: A previous study showed a strong and independent association between hemodynamic gain index (HGI) and all-cause mortality in a large cohort of men. The current study aimed to validate the association between HGI and all-cause mortality in a pilot cohort of women. Methods: The cohort included 606 women aged 54.1 ± 12 years who were prospectively followed for 8.0 ± 5.7 years. HGI was calculated according to a previously developed equation using heart rate (HR) and systolic blood pressure (SBP) responses from treadmill exercise testing [(HRpeak*SBPpeak)-(HRrest*SBPrest)]/(HRrest*SBPrest). Bivariable and multivariable Cox hazard models were analyzed for HGI and all-cause mortality. Results: During the follow-up, 48 participants (7.9%) died, and mean HGI was 1.86 ± 0.82 bpm/mmHg. In continuous bivariable and multivariable models, each one unit higher in HGI was associated with 64% and 45% reduced risks of mortality, respectively. The corresponding hazard ratios and 95% confidence intervals were: 0.36, (0.22–0.57), and 0.55 (0.33–0.91) (both p < 0.001). In a bivariable categorical model, compared to participants below the 25th percentile (HGI <1.27), participants who were between the 25th and 50th (HGI 1.27 to 1.77), 50th to 75th (HGI 1.78 to 2.39) and >75th percentile (HGI ≥2.4) exhibited 57%, 90% and 79% reductions in mortality risk (p trend <0.001), respectively. Conclusions: This validation study in women confirms that a higher HGI is associated with lower risk of all-cause mortality, supporting its prognostic value for risk stratification in clinical and research settings.