Risk Stratification With Hemodynamic Gain Index and Peak Rate-Pressure Product in Patients With Chronic Heart Failure Undergoing Treadmill Exercise Testing

Introduction: We recently demonstrated the combined prognostic value of two simple non-invasive parameters obtained from treadmill exercise testing in patients with HFrEF, the hemodynamic gain index (HGI) and peak rate-pressure product (pRPP). However, their prognostic value is yet to be validated in patients with undifferentiated HF syndrome. Hypothesis: Both HGI and pRPP predict all-cause mortality in patients with chronic HF. Methods: We identified 126,356 consecutive patients undergoing treadmill exercise testing for HF symptom evaluation between 1/1991-2/2015. Patients with a confirmed diagnosis of HF were included. HGI was calculated from [(SBPpeak x HRpeak) - (SBPrest x HRrest)]/(SBPrest x HRrest), and pRPP was calculated from SBPpeak x HRpeak. Hazard ratios per doubling of HGI and pRPP for all-cause mortality were estimated using multivariable Cox regression models with adjustment for traditional cardiovascular risk factors and exercise testing parameters (chronotropic reserve index, METs, abnormal heart rate recovery, and total exercise time). Optimal cut-off for HGI and pRPP were determined by the Youden’s index. Kaplan-Meier plots with log-rank test across patients with low or high HGI and pRPP were used. Results: There were 5,940 patients with symptomatic HF diagnosis included in the analysis (mean age 56.2±12.4 years, 68.1% male, 46.5% with CAD, 55.8% with beta-blocker use). During the median follow up of 7.1 years, 2,222 (37.4%) patients died. Higher both HGI and pRPP were associated with a lower risk of mortality (hazard ratio 0.85 [0.81-0.90] and 0.72 [0.62-0.84], respectively, all P <0.001). Optimal cut-off values for HGI and peak RPP were 1.06 and 18,966, respectively. Figure 1 shows Kaplan-Meier plots across patients with low and high HGI and pRPP (log-rank P <0.001). Conclusions: Both HGI and pRPP are predictors of mortality in patients with chronic HF and can be used for prognostication and referral for advanced HF therapy evaluation.