Purpose: Exercise improves the diagnostic performance of ankle-to-brachial index (ABI) in the detection of exercise-induced arterial endofibrosis (EIAE). Pressure values for all four limbs are required to calculate ABI, but rapid systemic pressure changes occur during the recovery period from exercise. We checked whether after exercise, ABI calculated from simultaneous measurements was better than from consecutive measurements for differentiating athletes with EIAE from normal athletes.
Methods: We studied 42 normal athletes and 42 athletes suffering from unilateral pain caused by histologically proven EIAE. Bilateral brachial and ankle (ASBP) systolic blood pressure levels were simultaneously measured in the supine position at rest and every minute during the first 4 min of the recovery from incremental maximal exercise. Using receiver operating characteristics curves (ROC), we compared the diagnostic performance of single-leg ASBP and ABI values and between-leg ASBP (DeltaASBP) and ABI (DeltaABI) differences, calculated from simultaneous (simu) versus consecutive (cons) measurements, to discriminate athletes with EIAE from normal athletes.
Results: For single-leg postexercise values, ROC curve area was significantly higher for ABIsimu compared with ASBPsimu (P < 0.05, r = 0.91) and ASBPrand (P < 0.05, r = 0.68). Areas (+/- SE of area) of the ROC curves for postexercise Delta ASBPsimu and Delta ABIsimu were 0.97 +/- 0.01 and 0.97 +/- 0.02, respectively, and were higher than areas for postexercise Delta ASBP and Delta ABI calculated from consecutive and random measurements (P < 0.01). Accuracy for postexercise Delta ASBPsimu and Delta ABIsimu in discriminating EIAE from normal athletes was 93% [95% CI; 85-97], with a cutoff point of 22 mm Hg and 0.10, respectively.
Conclusion: Delta ASBP and/or Delta ABI calculated from simultaneous pressure measurements should be recommended when searching for unilateral EIAE. Whether this result is applicable in the detection of early atherosclerotic lesions in sedentary subjects requires future investigation.