The short-term and long-term effects of warm or tepid cardioplegia.
BACKGROUND
Clinical studies of myocardial protection rarely identify differences in hard clinical outcomes after surgery, either early or late, because most trials lack sufficient statistical power to deal with low-frequency events.


METHODS
Prospectively collected data concerning all isolated coronary bypass operations from November 1989 to February 2000 were analyzed to determine the effects of cold blood cardioplegia and warm or tepid blood cardioplegia on early and late outcomes after surgery. Warm blood cardioplegia was used in 4532 patients, whereas cold blood cardioplegia was used in 1532. The allocation of patients to receive warm blood cardioplegia and cold blood cardioplegia was random in 749 cases and according to surgeon preference in the remainder. Most patients in the cold blood cardioplegia group had surgery earlier in the time course of the study, and most in the warm blood cardioplegia group underwent surgery later.


RESULTS
Perioperative death, myocardial infarction, and death or myocardial infarction were all more common in the cold blood cardioplegia group than in the warm blood cardioplegia group (death 2.5% vs 1.6%, P =.027, adjusted odds ratio 1.45, 95% confidence interval 0.95-2.22, P =.09; myocardial infarction 5.4% vs 2.4%, P <.0001, adjusted odds ratio 1.86, 95% confidence interval 1.36-2.53, P <.0001; death or myocardial infarction 7.3% vs. 3.8%, P <.0001, adjusted odds ratio 1.70, 95% confidence interval 1.30-2.21, P <.0001). Actuarial survival at 60 months was 91.1% +/- 1.4% in the warm blood cardioplegia group and 89.9% +/- 1.3% in the cold blood cardioplegia group (P =.09), whereas freedom from death or myocardial infarction was 84.7% +/- 1.8% and 83.2% +/- 1.6%, respectively (P =.16). In multivariate models, cold blood cardioplegia was associated with poorer survival (risk ratio 1.30, 95% confidence interval 0.96-1.75, P =.09) and freedom from any death or late myocardial infarction (risk ratio 1.93, 95% confidence interval 1.56-2.39, P =.0001).


CONCLUSIONS
In 6064 patients undergoing isolated coronary artery bypass grafting, warm or tepid blood cardioplegia may be associated with better early and late event-free survivals than is cold cardioplegia.
Mallidi
Hari R
HR
Division of Cardiovascular Surgery of Sunnybrook and Women's College Health Sciences Centre, Toronto, Ontario, Canada.
Sever
Jeri
J
Tamariz
Miguel
M
Singh
Steve
S
Hanayama
Naoji
N
Christakis
George T
GT
Bhatnagar
Gopal
G
Cutrara
Charles A
CA
Goldman
Bernard S
BS
Fremes
Stephen E
SE
D000206:Actuarial Analysis; D000368:Aged; D002303:Cardiac Output, Low / Q000209:etiology / Q000401:mortality; D002314:Cardioplegic Solutions; D003080:Cold Temperature / Q000009:adverse effects*; D015897:Comorbidity; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000401:mortality / Q000601:surgery*; D005260:Female; D006324:Heart Arrest, Induced / Q000009:adverse effects* / Q000379:methods*; D017052:Hospital Mortality; D006358:Hot Temperature / Q000009:adverse effects* / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000209:etiology / Q000401:mortality; D009864:Ontario / Q000453:epidemiology; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D020521:Stroke / Q000209:etiology / Q000401:mortality; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome
D002314:Cardioplegic Solutions