Exercise blood pressure, cardiorespiratory fitness and mortality risk.

Abstract Objective To assess the cardiorespiratory fitness (CRF) impact on the association between exercise blood pressure (BP) and mortality risk. Patients and methods We assessed CRF in 15,004 US Veterans (mean age 57.5 ± 11.2 years) who completed a standardized treadmill test between January 1, 1988 and July 28, 2017 and had no evidence of ischemia. They were classified as Unfit or Fit according to the age-specific metabolic equivalents (METs) achieved  52 mmHg). We applied multivariable Cox models to estimate hazard ratios (HR) and 95% confidence interval (CIs) for outcomes. Results Mortality risk was significantly elevated only in Unfit individuals with SBP-Reserve ≤52 mmHg compared to those with SBP-Reserve >52 mmHg (HR = 1.35; CI: 1.24–1.46; P  52 mmHg serving as the referent. Mortality risk was 92% higher (HR = 1.92%; 95% CI: 1.77–2.09; P  52 mmHg. Conclusion Low CRF was associated with increased mortality risk regardless of peak exercise SBP. The risk was substantially higher in individuals unable to augment their exercise SBP >52 mmHg beyond resting levels.