Abstract P512: Association Between Resting Rate Pressure Product and All-Cause Mortality Among United States Adults

Abstract

Background: Rate pressure product (RPP) is a measure of myocardial oxygen consumption and often used to quantify cardiac exercise workload. We sought to determine whether resting RPP was associated with all-cause mortality in healthy U.S. adults. Methods: This was a nationally representative, retrospective cohort study of the 1999-2018 National Health and Nutrition Examination Survey (NHANES), linked to the National Death Index through 2019. We included adult, non-pregnant participants without cardiovascular disease, kidney dysfunction, hypertension, diabetes, or current chronotropic agent use. RPP was calculated as the product of mean systolic BP (of 3 sitting BPs) and resting heart rate, and classified into quintiles (Q1≤7300, Q2 [Ref]: 7300-8250, Q3: 8250-9200, Q4: 9200-10400, Q5: >10400). We used multivariable Cox regression to estimate risk of all-cause mortality, adjusting for demographics, CVD risk factors, and comorbidities, and accounting for the survey design. Results: Among 19,954 participants (mean age 40y; 9,653 [48%] female; 8,056 [66%] non-Hispanic White), 1,013 died over a median follow-up of 10.3 years (IQR, 5.6-15.5). Adults in Q3-Q5 had significantly increased unadjusted risk of all-cause mortality compared to Q2 (HR [95% CI], Q1: 0.89 [0.50,1.58], Q3: 1.69 [1.06,2.72], Q4: 1.97 [1.16,3.34], Q5: 2.69 [1.71,4.22]). Adjustment for covariates attenuated risks of mortality but remained 61% higher for Q5 (Q2 [Ref], Q1: 1.02 [0.77,1.36], Q3: 1.09 [0.85,1.40], Q4: 1.22 [0.93,1.59], Q5: 1.61 [1.25,2.07]). When stratifying by gender, men, but not women, demonstrated increased risk of mortality in Q4 and Q5 (Women, Q4: 0.84 [0.54,1.31], Q5: 1.33 [0.89,1.98]; Men, Q4: 1.53 [1.07,2.18], Q5: 1.79 [1.30,2.46]). Conclusion: Healthy adult participants with a resting RPP greater than 10,400 had 61% higher risk of all-cause mortality compared to a RPP less than or equal to 7,300. This effect seems to be more pronounced in men than women. Further longitudinal studies are needed to understand the independent, predictive value of RPP and factors (e.g. aerobic activity) driving RPP.