Abstract 12059: High Cardiorespiratory Fitness is Associated With Larger Coronary Artery Diameters
Introduction: Cardiorespiratory fitness is inversely associated with morbidity and mortality even after adjustment for traditional risk factors. The biological mechanism for the protective effect of high fitness is largely unknown.
Hypothesis: We hypothesized that high fitness would be associated with larger coronary artery diameters independent of traditional risk factors.
Methods: In this study, 500 men with a coronary artery calcium score (CACS) < 10 were evaluated, with 100 from each age-adjusted fitness quintile (very poor, 1-20%; poor, 21-39%; fair, 40-59%; good, 60-79%; and excellent, 80-100%). Each participant had undergone fitness assessment with an exercise treadmill test on the day of CACS. Blinded to the fitness category, one of us measured the proximal diameters of the left main (LM), left anterior descending (LAD), left circumflex (LCx), and the right coronary (RCA) arteries. Spearman correlations were calculated for the diameters of each coronary artery with treadmill time and for the sum of artery diameters with treadmill time. Linear mixed-effects regression was used to estimate the association between fitness and coronary artery diameters while adjusting for potential confounders.
Results: Each coronary artery diameter (LM r=0.12, p=0.009; LAD r=0.11, p=0.02; LCx r=0.10, p=0.02; RCA r=0.18, p<0.0001) and the sum of artery diameters (r=0.19, p<0.0001) were positively correlated with fitness after adjusting for body surface area. The RCA diameter and the sum of artery diameters remained positively correlated with fitness after further adjusting for traditional risk factors. In multivariate analyses, men in the highest fitness quintile had significantly larger coronary artery diameters compared to those in the lowest fitness quintile [β=0.85 mm (SE=0.27)]. A positive linear trend was observed across fitness quintiles and the LM (p=0.008), LAD (p=0.05), RCA (p<0.0001) diameters, and the sum of coronary artery diameters (p=0.0003). When examined continuously, each minute increase in treadmill time was associated with larger diameters (β=0.08 mm (SE=0.02) p<0.001).
Conclusion: Higher fitness is positively associated with larger coronary artery diameters.
Author Disclosures: J. Ho: None. J. Cannaday: None. C. Finley: None. C. Barlow: None. W. Wade: None. D. Reinhardt: None. J. Ellis: None. L. DeFina: None. L. Gibbons: None. K. Cooper: None.
- © 2014 by American Heart Association, Inc.