Myocardial protection in cardiac surgery patients requiring prolonged aortic cross-clamp times: a single-center evaluation of clinical outcomes comparing two blood cardioplegic strategies.
OBJECTIVE
The aim of this study was to evaluate the impact of intermittent warm (IWC) versus intermittent cold blood cardioplegia (ICC) in high-risk patients that require prolonged periods of aortic cross-clamping during on-pump cardiac surgery.


METHODS
From 3527 consecutive patients undergoing on-pump cardiac surgery, 520 patients were retrospectively identified that required prolonged aortic cross-clamp ≥ 75 min. Myocardial protection was performed with ICC (N.=280) or IWC (N.=240). Groups were compared regarding clinical outcomes, myocardial injury (CK-MB, cTnT) and multivariate analysis was performed to assess the impact of applied cardioplegia on 30-day all-cause mortality, cardiac death, perioperative myocardial injury (PM) and major adverse cardiac events (MACE).


RESULTS
Demographic data, mean logistic Euroscore, aortic-cross-clamping and CPB time were comparable between groups. Patients with ICC needed more intraoperative defibrillations, had more postoperative blood transfusions and a prolonged hospital stay when compared to the IWC-group (P < 0.05). Thirty-day all-cause mortality tended to be higher in IWC (11% vs. 6%; P = 0.083) with significantly higher cardiac mortality (9% vs. 4%; P=0.015) compared to ICC. Myocardial injury was more pronounced in the IWC-group with a higher incidence of PMI (IWC: 17% vs. ICC:6%; P < 0.05) and MACE (IWC:37% vs. ICC:25%; P < 0.05). Groups did not differ regarding other postoperative clinical outcomes. Multivariate analysis revealed IWC to be independently predictive (P < 0.05) for 30-day all-cause mortality (OR:2.42; 95% CI:1.04-5.05), cardiac death (OR:3.57; 95% CI:1.49-8.85), MACE (OR:1.87; 95% CI:1.22-2.87) and PMI (OR:3.46; 95% CI:1.86-6.41).


CONCLUSIONS
ICC results in less myocardial damage and reduced postoperative cardiac mortality and morbidity in patients requiring extended periods of aortic-cross-clamping during on-pump cardiac surgery, suggesting superior cardioprotection when compared to IWC.
Department of Cardiothoracic Surgery, Heart Center of the University of Cologne, Cologne, Germany. oliver.liakopoulos@uk-koeln.de
O J
OJ
Liakopoulos
E W
EW
Kuhn
Y H
YH
Choi
W
W
Chang
T
T
Wittwer
N
N
Madershahian
G
G
Wassmer
T
T
Wahlers
D000368:Aged; D001011:Aorta / Q000601:surgery*; D001803:Blood Transfusion; D006348:Cardiac Surgical Procedures / Q000009:adverse effects / Q000401:mortality; D002314:Cardioplegic Solutions / Q000008:administration & dosage*; D003250:Constriction; D004554:Electric Countershock; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods*; D006331:Heart Diseases / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D006801:Humans; D007558:Italy; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013696:Temperature; D013997:Time Factors; D016896:Treatment Outcome
D002314:Cardioplegic Solutions