Postconditioning the human heart with adenosine in heart valve replacement surgery

Background. The effect of adenosine postconditioning on myocardial protection in cardiac surgery remains uncertain. The present study evaluated the safety, feasibility, and beneficial effect of adenosine postconditioning as an adjunct to predominantly used cold-blood cardioplegic myocardial protection method in the setting of heart valve replacement operations. Methods. Sixty patients with rheumatic heart valve disease undergoing heart valve replacement operations were randomized to an adenosine (1.5 mg/kg) or saline ( as control) bolus injection through an arterial catheter immediately after the aorta cross-clamp was removed. The surgical indications were similar in both groups, and heart valve replacement was successful in all patients. Results. The extubation time and postoperative hospital time were similar in both groups. Compared with the control group, however, the inotrope scores in the intensive care unit (ICU) were much lower ( p < 0.01), and the ICU time was significantly shorter ( p < 0.05) in adenosine group. More important, cardiac troponin I release was less in the adenosine group, especially at 12 and 24 hours after reperfusion ( p < 0.01), and total cardiac troponin I release estimated with the area under curve was also significantly reduced during the first 24 hours after reperfusion ( p < 0.01). Conclusions. A 1.5-mg/kg bolus administration of adenosine through an arterial catheter immediately after the aorta cross-clamp is removed is feasible and well tolerated in patients undergoing heart valve replacement. An adenosine postconditioning adjunct to high potassium cold blood myocardial protection is related to less troponin I release, less inotropic drug use, and shorter ICU stay.