Abstract 15834: Joint Associations Between Resting Heart Rate and Blood Pressure on All-Cause Mortality

Abstract

Introduction: Both blood pressure and heart rate (HR) are important factors that constitute hemodynamic status. Hypothesis: We aimed to determine whether HR was independently associated with all-cause mortality and whether HR modified the association between systolic blood pressure (SBP) and all-cause mortality. Methods: We included adults aged ≥20 years from the 1999-2018 National Health and Nutrition Examination Surveys without cardiovascular disease, chronic kidney disease, chronic obstructive pulmonary disease, cancer, asthma, or beta blocker use. Resting HR was categorized into 10 beats-per-min increments, and SBP in 10-20 mmHg increments as shown in Table 1. Our primary outcome was all-cause mortality, determined using linkage to the National Death Index through 2019. We used multivariable Cox regression, stratified by HTN status and adjusted for the survey design. Results: Among 27,369 participants, 5984 (22%) had diagnosed HTN. A HR ≥80 was associated with at least a 30% increase in mortality risk, regardless of HTN status (Table 1). Among normotensive participants, a HR ≥80 was associated with higher mortality risk compared to HR <80 at all SBPs except for SBP ≥180 (Table 1). While there was significant interaction between continuous HR and SBP on all-cause mortality (p=0.02), there was no evidence of significant effect modification within individual SBP categories. Conclusions: A HR ≥80 was independently associated with increased all-cause mortality risk, regardless of HTN diagnosis. HR may be a surrogate for cardiorespiratory fitness. Further studies understanding the joint associations between SBP and HR are needed in both normotensive and hypertensive individuals.