Increased incidence of radial artery calcification in patients with diabetes mellitus.

BACKGROUND: The radial artery (RA) has become a popular conduit for coronary artery bypass (CAB). Preoperative RA evaluation in CAB patients has focused on ulnar collateral circulation to the hand and not on the conduit itself, yet the RA is prone to atherosclerosis and perhaps calcification, particularly in patients with diabetes mellitus (DM). We sought to determine the incidence of RA calcific disease in diabetic vs nondiabetic patients using ultrasonography to establish its role in preoperative evaluation of CAB patients. METHODS: Ultrasound images of the RA were obtained in 102 men (49 with DM) referred to a vascular laboratory. For each patient, a RA calcification index (CI; 0-4) was derived from separate scores accounting for calcification density, longitudinal vessel involvement, and bilaterality. Differences between diabetic and nondiabetic patients were determined by unpaired t test. RESULTS: Mean (+/-SEM) CI was greater in diabetic patients vs nondiabetics (2.32 +/- 0.21 vs 1.17 +/- 0.20; P < 0.0001), due mainly to an increase in dense calcification, which was observed in 17 (34%) diabetics vs 5 (9.6%) nondiabetics (P = 0.007). Calcifications were completely absent in 27 (52%) nondiabetics vs 9 (18%) diabetics (P = 0.000). CONCLUSIONS: These data indicate that both the incidence and the severity of RA calcific disease are increased by DM. Preoperative imaging of the RA should be considered in diabetic CAB candidates and perhaps in nondiabetics with multiple risk factors to avoid unnecessary forearm exploration or inadvertent use of a diseased conduit.