Objective: This study highlights the protective effects of montelukast on myocardial ischemic reperfusion injury induced by cardiopulmonary bypass during valve replacement surgery.

Methods: A total of 60 patients with valvular disease undergoing elective valve surgery were enrolled in this randomized single-blinded study. Participants were divided into two main groups: Montelukast-treated group consisted of 30 patients who were given 10 mg montelukast sodium (Singulair®, MSD, USA) tablet, once daily at bedtime for 3 days before valve surgery. Control group consisted of 30 patients who underwent valve surgery without taking montelukast tablets. Blood samples were collected at following times (T0 ; T1 before aortic cross clamp; T2 after aortic cross clamp; and T3 24 h after the surgery), for measuring several inflammatory markers. Ejection fraction (EF) was measured before surgery and three months after surgery. Pulmonary functions were measured before and after the surgery in both study groups.

Results: There were significant increase in the levels of TNF-a, IL-6, a2 macroglobulin/creatinine ratio and CTnI, in the control group compared to the montelukast-treated group among different study times, (P < 0.05). In addition, the EF was significantly higher in the montelukast-treated group after the valve surgery, (P < 0.05). Levels of forced vital capacity (FVC), forced expiratory volume 1 (FEV1 ), and FEV1 /FVC ratio where significantly higher in the montelukast-treated group than the control group, (P < 0.05).

Conclusion: This study shows the benefits of using pre-surgical montelukast supplement in ameliorating the inflammatory process in patients undergoing cardiopulmonary bypass during valve replacement surgery.