Aim: 

We investigated in a single-center retrospective study early outcomes of intermittent warm blood and cold crystalloid St. Thomas cardioplegia in patients referred to CABG due to acute coronary syndromes.

Methods: 

336 consecutive patients underwent isolated on-pump CABG (unstable angina=234, N-STE-MI=66, STE-MI=36). Cardiac arrest was obtained with warm blood cardioplegia (WBC-group=215) or cold crystalloid cardioplegia (CCC-group=121).

Results: 

Baseline and preoperative characteristics including serum levels of CK-MB and C- Troponin-I enzymes were similar in two cardioplegia groups. As compared with CCC-group, required number of cardioplegia’s doses per-patient was higher in WBC group (2.6±0.8 vs 2.1±0.8; P<0.0001), despite lower number of distal coronary-artery anastomoses (2.8±0.7 vs 3.0±0.8; P=0.027), and shorter aortic cross-clamp time (60.0±20.5 vs 66.7±20.5 min.;P<0.01). Completeness of revascularization was similar (100% vs 98%). Operative mortality (3.3% vs 1.4%), low cardiac output syndrome (5.8% vs 4.6%), postoperative left-ventricular ejection fraction (0.52±0.07 vs 0.53±0.07) were similar. CK-MB and C-troponin-I releases were similar for two cardioplegia groups at time 0, 12 hours and 24 hours after CABG. C-Troponin-I and CK:MB releases at time 0, 12 and 24 hours were lower when WBC was repeated within 18 min. in comparison with 20–25 min. (P</=0.05,for all comparisons). As well as, CK-MB/CPK- total ratio>5% was significantly lower at 12 and 24 hours when WBC administration was repeated within 18 min. Cross-clamp time (64.2±21.6 vs 65.2±29.5 min.) did not significantly correlate with CK-MB/CPK-total ratio>5% compared with lower ratios.

Conclusions: 

Both types of cardioplegia guarantee equivalent early outcomes in patients undergoing CABG for acute coronary syndromes. WBC allows better protection when administered in 18-minute re-dosing interval.