Impaired acute collateral recruitment as a possible mechanism for increased cardiac adverse events in patients with diabetes mellitus

Background The mortality of coronary artery disease is increased in diabetic patients. An impaired collateral function is considered a possible explanation. This study should assess the influence of diabetes on collaterals by direct invasive assessment of collateral function. Methods In 90 consecutive patients with a chronic coronary occlusion (TCO) of >2 weeks duration a recanalization was done. Thirty patients with diabetes (33%) were compared with 60 (67%) without diabetes. Blood flow velocity and pressure were measured distal to the occlusion by intracoronary Doppler and pressure wires before PTCA, and again after PTCA during a final balloon reocclusion to assess acute recruitment of collaterals. Resistance indexes for collaterals (RColl) and peripheral microcirculation (RP) were calculated. Results The RColl(diabetics: 8.1±6.8 vs nondiabetics: 8.7±6.7mmHgcm−1s−1; p=0.68) and RP(5.6±4.2 vs 6.6±3.8mmHgcm−1s−1; p=0.30) were similar in diabetic and nondiabetic patients before recanalization. During balloon reocclusion both RColland RPincreased. This increase was significantly more pronounced in diabetic than in nondiabetic patients in TCOs