We performed a retrospective analysis of consecutive patients referred at Mayo Clinic (Rochester, Minn) for upper extremity arterial assessment during a 27-month period. Finger-brachial index, skin blood flow (in arbitrary units [a.u.]), and skin temperature (in degrees Celsius) were recorded in each digit on the pulp at baseline and after a thermal challenge test (hand placed in a thermal box at 47.0掳C for 15聽minutes). Angiogram analysis was blinded and performed by a radiologist using a vascularization scale ranging from 0 (no vessel) to 4 (normal). The receiver operating characteristic curve was used to define a specific cutoff point to detect DOAD. Twenty-two patients had LDF measurements and complete angiograms.
A total of 185 digits were analyzed because some patients had only analysis of one hand. The best area under the curve (AUC) was 0.98 (range, 0.94-0.99) for postwarming skin blood flow, with a cutoff point of 鈮?06 a.u. This AUC was statistically different from AUCs of all the other tests (P聽< .01). Sensitivity and specificity were 93% (95% confidence interval, 85%-97%) and 96% (95% confidence interval, 90%-99%), respectively.
LDF combined with a thermal challenge is highly accurate, safe, and noninvasive means to detect DOAD.