Allopurinol Protection in Patients Undergoing Coronary Artery Bypass Graft Surgery

Objective: Through the evaluation of randomized clinical trials using a statistical methodology consisting of comparative assessment, we sought to determine the conditions under which allopurinol was a protective agent for patients undergoing coronary artery bypass grafting (CABG). Methods: The medical literature was searched for all human clinical trials from 1966 to 2008 examining the use of allopurinol in CABG. The final articles were divided into two groups based on the effectiveness of allopurinol, as determined by the requirement of postoperative inotropic/mechanical LV support. In four of the studies patients had high risk factors for CABG and this group was considered the high-risk (HR) group. The other four studies found that allopurinol-treated patients did as well as their own controls. This group had few risk factors and was considered the low-risk (LR) group. Results: This study demonstrated that HR patients who received allopurinol during CABG had significantly better results than the HR patients without allopurinol treatment. Patients receiving allopurinol in the group with LR factors had no significant differences compared with the LR controls. HR allopurinol patients did significantly better (p <.05) than LR allopurinol patients undergoing CABG. Conclusions: It was observed that patients with HR factors benefited more from allopurinol than patients with LR factors. Our findings lead us to believe that it is possible that allopurinol is efficacious in patients with a potentially higher oxidant buildup as a result of increased cardiovascular risk. This hypothesis needs to be confirmed.