Efficiency of L-arginine enriched cardioplegia and non-cardioplegic reperfusion in ischemic hearts.
OBJECTIVE
Endothelial dysfunction with decreased nitric oxide (NO) levels has been implicated on reperfusion injury. Although L-arginine has been shown to diminish reperfusion injury in in vitro studies, clinical studies were very limited.


METHODS
Forty patients with acute myocardial ischemia undergoing CABG were randomized to a study and a control group. L-Arginine was added to cardioplegia solutions in study group. A non-cardioplegic warm blood solution with 8 mmol/l L-arginine infused for controlled reperfusion. Control patients received same protocol without L-arginine. Myocardial O2, lactate, nitrite and malondialdehyde extractions were measured in addition to calculation of CK-MB/CPK ratio and hemodynamic data.


RESULTS
While there was no mortality in study group, one patient in control group died. Overall and nitrite (P=0.01) and lactate extractions (P=0.04) was higher in study and control groups, respectively. Myocardial O2 uptake was higher and malondialdehyde extraction was lower in study group. CK-MB/CPK ratio at postoperative sixth hour was also significantly lower in study group. Ninety percent of the study group had spontaneous return of the sinus rhythm, while 80% of the control patients required defibrillation (P<0.0001). In addition to significantly better hemodynamics, perioperative myocardial infarction incidence was lower (P=0.037), the length of intensive care unit (P=0.009) and hospital (0.014) stays were shorter in study group.


CONCLUSIONS
Use of L-arginine for protection of acutely ischemic myocardium appears to be a safe technique. L-Arginine supplementation increased NO levels and attenuated free O2 radical mediated myocardial injury. Controlled reperfusion with l-arginine enriched non-cardioplegic blood could be a new therapeutic entity to diminish ischemia/reperfusion injury.
Kiziltepe
Ugursay
U
Department of Cardiovascular Surgery, Cardiac Center, Ankara University School of Medicine, Sokollu Cad. Nakis Sok., 8/14 Dikmen, Ankara 06460, Turkey. uk9316@hotmail.com
Tunçtan
Bahar
B
Eyileten
Zeynep Bastuzel
ZB
Sirlak
Mustafa
M
Arikbuku
Mehmet
M
Tasoz
Refik
R
Uysalel
Adnan
A
Ozyurda
Umit
U
D000328:Adult; D000368:Aged; D001120:Arginine / Q000627:therapeutic use*; D002314:Cardioplegic Solutions / Q000627:therapeutic use*; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood / Q000601:surgery*; D015425:Myocardial Reperfusion / Q000379:methods*; D015428:Myocardial Reperfusion Injury / Q000209:etiology / Q000517:prevention & control*
D002314:Cardioplegic Solutions; D001120:Arginine