CORONARY-ARTERY SURGERY ON THE BEATING HEART UNDER CARDIOPULMONARY BYPASS IN HIGH-RISK PATIENTS - AN ACCEPTABLE COMPROMISE

Coronary artery surgery with cardioplegia in high risk patients carrie s a risk of myocardial ischaemia and, without cardiopulmonary bypass, is not always technically feasible. The authors assessed an alternativ e, surgery on the beating heart with haemodynamic assist by cardiopulm onary bypass in 43 consecutive patients with poor left ventricular fun ction (mean ejection fraction : 0.26), evolving myocardial ischaemia o r acute myocardial infarction, old age (mean : 79.5 years) and comorbi d conditions. Results were assessed mainly on clinical criteria. In ad dition, 9 patients had pre- and post-cardiopulmonary bypass measuremen ts of markers of myocardial ischaemia (troponine Ic) and systemic infl ammation (interleukines 6 and 10, elastase). In 6 cases, right atrial biopsy was analysed for expression of messenger ribonucleic acid codin g for heat shock protein (HSP) 70 : the data were compared with those of patients operated under warm blood cardioplegia. There was one card iac death and one myocardial infarction. Myocardial conservation was c onfirmed by the minimal increase in troponine Ic levels and the signif icant increase in HSP 70 in RNA suggesting myocardial adaptation to st ress. On the other hand, the minimal concentrations of mediators of in flammation were not significantly changed. In selected high risk patie nts, coronary revascularisation on the beating heart under cardiopulmo nary bypass could be a valuable alternative. It conserves the potentia lly deleterious effects of cardiopulmonary bypass but peroperative glo bal myocardial ischaemia, an important facor in the aggressivity of ca rdiac surgery, is eliminated.