Does intermittent cross-clamp fibrillation provide equivalent myocardial protection compared to cardioplegia in patients undergoing bypass graft revascularisation?

Abstract

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: does intermittent cross-clamp fibrillation provide equivalent myocardial protection compared to cardioplegia in patients undergoing bypass graft revascularisation? Altogether, 58 papers were found using the reported search, of which 13 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. We identified 13 studies, of which eight were randomised prospective trials. None of these studies found increased mortality, seven analyzed serum cardiac enzymes and showed that intermittent ischemic arrest provides equal or better protection compared to cardioplegic techniques. Two studies found an increased usage of inotropes and intra aortic balloon pump (IABP) in the intermittent ischemic arrest group. We conclude that intermittent cross-clamp fibrillation is a versatile and cost-effective method of myocardial protection, with the immediate postoperative outcome comparable to cardioplegic arrest in first-time coronary artery bypass graft (CABG). The ischaemic duration associated with intermittent cross-clamp fibrillation is invariably shorter than that associated with cardioplegic arrest, and this may be one explanation for the comparable outcomes. There may also be an element of preconditioning protection during the intermittent cross-clamp fibrillation method, as has been shown experimentally. During elective CABG in patients with no clinical evidence of aortic or cerebro-vascular disease, the incidence of peri-operative microemboli (ME) and postoperative neuropsychological disturbances are shown to be comparable with both techniques of myocardial preservation.