Abstract 15328: Higher Non-exercise Estimated Cardiorespiratory Fitness in Midlife is Associated With Lower Risk of Incident Heart Failure: The Framingham Heart Study
Introduction: Non-exercise estimated cardiorespiratory fitness (eCRF) algorithms have shown similar accuracy to CRF estimated from submaximal and maximal exercise tests in healthy adults. Using easily accessible health indicators, eCRF measurement does not involve in-person exercise testing, trained personnel, or specialized equipment for measuring CRF. Thus, eCRF may be a cost-effective alternative for heart disease risk stratification. The relation between eCRF and Heart failure (HF) remains unclear. Hypothesis: We hypothesized that higher midlife eCRF is associated with a lower risk of incident HF in later life. Methods: We evaluated 2,226 Framingham Offspring cohort participants attending examination cycles 2 and 7 (mean age of 42- 61years; 53% women). We used a validated longitudinal non-exercise algorithm for eCRF including age, sex, body mass index, waist circumference, resting heart rate, physical activity, and smoking status. Midlife eCRF was defined as a sex-specific standardized average of eCRF (z-score of the average eCRF with mean=0 and a standard deviation [SD]=1) between cycles 2 and 7. The sex-specific midlife eCRF were then categorized into three groups based on tertiles and was also analyzed as a continuous variable (per 1 SD increment). We used multivariable Cox proportional hazards regression models for pooled sexes to relate the midlife eCRF to incident HF after examination cycle 7. Results: Overall, 189 participants developed HF during a median of 17 years of follow-up. Participants in either moderate or high eCRF group experienced a 52% lower risk of HF compared to those in the low eCRF group, after adjustment for potential confounders. Additionally, each SD increment in midlife eCRF was associated with a 40% lower risk of HF in later life. The associations remained significant after excluding participants on antihypertensive treatment (Table). Conclusions: Lower eCRF during midlife may be a marker of higher HF risk in later life.