Cardioplegic arrest with image-arginine improves myocardial protection: results of a prospective randomized clinical trial

Background. Blood cardioplegic arrest remains the method of choice for myocardial protection. image-arginine has been suggested to improve protection through an increase in nitric oxide production. Methods. A prospective, randomized, double-blinded clinical trial comparing standard blood cardioplegic solution to image-arginine-enriched solution (7.5 g/500 mL) enrolled 200 patients undergoing coronary artery bypass grafting. Clinical data and biochemical markers of ischemia were recorded. Warm blood cardioplegia (33°C) was administered in 74% of patients and cold blood (20°C) was used in 26% of patients. Both groups averaged three grafts per patient. Results. There were two (2%) deaths in both groups. There were four (4%) myocardial infarctions (MI) in the control group and six (6%) infarctions in the image-arginine group (p = 0.5). For the 190 patients without MI, serum levels of troponin T averaged 0.40 ± 0.43, 0.38 ± 0.42, and 0.39 ± 0.50 μg/L in control patients compared with 0.28 ± 0.22, 0.24 ± 0.18, and 0.27 ± 0.20 μg/L in image-arginine patients, respectively, 12, 24 and 48 hours after coronary artery bypass grafting (p = 0.03). The cardiac index averaged 2.7 ± 0.8 L · min−1 · m−2 in control patients and 2.9 ± 0.7 L · min−1 · m−2 in arginine patients immediately after surgery (p = 0.09). Intensive care unit and hospital length of stay averaged 3.5 ± 5 days and 7.3 ± 6 days in control patients compared with 2.5 ± 3 days and 6.1 ± 4 days in arginine patients (p = 0.09). Conclusions. image-arginine-supplemented blood cardioplegic solution is associated with reduced release of biochemical markers of myocardial damage, suggesting improved myocardial protection.