Relations Between Physical Activity, Subclinical Myocardial Injury, and Cardiovascular Mortality in the General...

We examined the association between poor physical activity (PA) and subclinical myocardial injury (SC-MI), and how concomitant exposure to poor PA and SC-MI modifies their association with cardiovascular disease (CVD) mortality. This analysis included 6,044 participants free of CVD from the NHANES-III survey. Leisure time PA was defined as: ideal (3 to 5.99 METs and ≥5 times/week or any PA with ≥6METs and ≥3times/week), intermediate (any activity other than ideal), or poor (no activity at all). SC-MI was defined as an electrocardiographic cardiac infarction/injury score ≥10 units. CVD mortality was ascertained from the National Death Index. In multivariable logistic regression analysis, poor PA (odds ratio [OR] [95% confidence interval, CI]: 1.30 [1.10 to 1.54]) and intermediate PA (OR [95%CI]: 1.19 [1.02 to 1.38]), compared with ideal PA, were associated with an increased odds of SC-MI. During a median follow-up of 14 years, 589 CVD deaths occurred. In multivariable Cox-proportional hazard analysis, the presence (vs absence) of SC-MI was associated with a 33% increased risk of CVD mortality whereas poor (vs ideal) PA was associated with a 67% increased risk of CVD mortality (HR [95%CI]: 1.33 [1.11 to 1.58] and 1.67 [1.37 to 2.05], respectively). Additionally, the concomitant presence of both poor PA and SC-MI were associated with a higher risk of CVD mortality (HR [95%CI]: 2.25[1.68 to 3.00]) compared with ideal PA and the absence of SC-MI. In conclusion, poor PA is associated with an increased risk of SC-MI and their concomitant presence is associated with a marked increase in CVD mortality, underscoring the potential role of PA in preventing clinical and subclinical CVD outcomes.