Occurrence of myocardial ischemia immediately after coronary revascularization using radial arterial conduits

Objective: To assess the incidence of myocardial ischemia in patients receiving radial arterial and left internal thoracic arterial conduits (RA+LITA) during the postrevascularization period. Design: Nonrandomized observational sequential cohort. Setting: University hospital. Participants: Thirty adult patients, scheduled for elective coronary artery bypass graft surgery with RA+LITA, compared with 30 patients who received saphenous vein graft and left internal thoracic arterial conduits. Interventions: None. Measurements and Main Results: Myocardial ischemic episodes were defined as reversible ST-segment depressions or elevations ≥1 mm and ≥2 mm at J +60 msec and lasting ≥1 minute using 2-channel Holter monitoring. During the post-cardiopulmonary bypass period, a significantly higher number of patients with ≥2 mm ischemic episodes (21.7%; p = 0.015) and higher number of ≥2 mm ischemic episodes per hour (0.19 ± 0.4 episodes/hr; p = 0.03) were observed in the radial artery group versus the comparison group (0% of patients and 0 episodes/hr). During the postoperative period (24 hours), a significantly longer duration of ≥2 mm ischemic episodes was observed in the radial artery group (24 ± 33 minutes v 8.4 ± 21 minutes; p = 0.046). Radial artery graft, preoperative calcium antagonists, and pulmonary arterial mean pressure were independent predictors of the duration and area under the ST-segment curve of ≥2 mm ischemic episodes during the postoperative period. Conclusion: There is an association between the use of the radial artery graft and the incidence and severity of ≥2 mm postrevascularization ischemic episodes.