Abstract
Background We compared the effect of intermittent blood and histidine-tryptophan-ketoglutarate
(HTK) solution of Bretschneider on myocardial histopathology and perioperative outcome.
Methods Forty adult cardiac surgery patients were grouped into two (n = 20 for each): (1) Intermittent blood cardioplegia (IBC): had repeated cold 4:1
blood cardioplegia and (2) HTK: had a single dose of cold HTK for cardioprotection.
Creatine kinase (CK)-MB, Troponin-I (cTn-I), pH, and lactate were studied in coronary
sinus blood before and after aortic cross-clamping (AXC) and systemic blood at postoperative
6th , 24th , and 48th hours. Myocardial biopsy was performed before and after AXC for light microscopy.
Vacuolation, inflammation, edema, and glycogen were graded semiquantitatively (from
0 to 3). The myocardial apoptotic index was evaluated via the terminal deoxynucleotidyl
transferase dUTP nick end labeling.
Results There were no differences in perioperative clinical outcomes between the groups.
The coronary sinus samples after AXC were more acidotic (7.15 ± 0.14 vs. 7.32 ± 0.07,
p = 0.001) and revealed higher CK-MB (21.0 ± 12.81 vs. 12.60 ± 11.80, p = 0.008) in HTK compared with IBC. The HTK had significantly a higher amount of erythrocyte
suspension intraoperatively compared with IBC (0.21 ± 0.53 vs. 1.68 ± 0.93 U, p = 0.001). Microscopically, myocardial edema was more pronounced in HTK compared with
IBC after AXC (2.25 ± 0.91 vs. 1.50 ± 0.04, p = 0.013). While a significant increase in the apoptotic index was seen after AXC
in both groups (p = 0.001), no difference was detected between the groups (p = 0.417).
Conclusion IBC and HTK have a similar clinical outcome and protective effect, except for more
pronounced myocardial edema and increased need for intraoperative transfusion with
HTK.
Keywords ischemia - histopathology - cardiac - myocardial protection
