Percent Predicted Peak Exercise Oxygen Pulse Provides Insights Into Ventricular-Vascular Response and Prognosticates HFpEF

Background: Peak oxygen consumption and oxygen pulse along with their respective percent predicted measures are gold standards of exercise capacity. To date, no studies have investigated the relationship between percent predicted peak oxygen pulse (%PredOP) and ventricular-vascular response (VVR) and the association of %PredOP with all-cause mortality in heart failure with preserved ejection fraction (HFpEF) patients.

Objectives: The authors investigated the association between: 1) CPET measures of %PredOP and VVR; and 2) %PredOP and all-cause mortality in HFpEF patients.

Methods: Our cohort of 154 HFpEF patients underwent invasive CPET and were grouped into %PredOP tertiles. The association between percent predicted Fick components and markers of VVR (ie, proportionate pulse pressure, effective arterial elastance) was determined with correlation analysis. The Cox proportional hazards model was used to identify predictors of mortality.

Results: The participants' mean age was 57 ± 15 years. Higher %PredOP correlated with higher exercise capacity. In terms of VVR, higher %PredOP correlated with a lower pressure for a given preload (effective arterial elastance r = -0.45,  < 0.001 and proportionate pulse pressure r = -0.22,  = 0.008). %PredOP distinguished normal and abnormal percent predicted peak stroke volume and correlated positively with %PredVO (r = 0.61,  < 0.001). Participants had a median follow-up time of 5.6 years and 15% death. Adjusted for age and body mass index, there was a 5% relative reduction in mortality (HR: 0.95, 95% CI: 0.92-0.98,  = 0.003) for every percent increase in %PredOP.

Conclusions: In HFpEF, %PredOP is a VVR marker that can stratify invasive parameters such as percent predicted peak stroke volume. %PredOP is an independent prognostic marker for all-cause mortality and those with higher %PredOP exhibited longer survival.