Cardioplegic arrest with L-arginine improves myocardial protection: results of a prospective randomized clinical trial.
BACKGROUND
Blood cardioplegic arrest remains the method of choice for myocardial protection. L-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 L-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 degrees C) was administered in 74% of patients and cold blood (20 degrees 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 L-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 microg/L in control patients compared with 0.28+/-0.22, 0.24+/-0.18, and 0.27+/-0.20 microg/L in L-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 x min(-1) x m(-2) in control patients and 2.9+/-0.7 L x min(-1) x 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
L-arginine-supplemented blood cardioplegic solution is associated with reduced release of biochemical markers of myocardial damage, suggesting improved myocardial protection.
Carrier
Michel
M
Department of Surgery, Anesthesia, and Medicine, Montreal Heart Institute and the University of Montreal, Quebec, Canada. carrier@icm.umontreal.ca
Pellerin
Michel
M
Perrault
Louis P
LP
Bouchard
Denis
D
Pagé
Pierre
P
Searle
Norman
N
Lavoie
Joel
J
D000368:Aged; D001120:Arginine / Q000627:therapeutic use*; D015415:Biomarkers; D002314:Cardioplegic Solutions; D001026:Coronary Artery Bypass; D004311:Double-Blind Method; D005260:Female; D006324:Heart Arrest, Induced; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D020107:Troponin T / Q000097:blood
D015415:Biomarkers; D002314:Cardioplegic Solutions; D020107:Troponin T; D001120:Arginine