Impact of age on early outcome after coronary bypass graft surgery using minimized versus conventional extracorporeal circulation

Minimally invasive extracorporeal circulation is a cost-effective alternative to conventional extracorporeal circulation for coronary artery bypass grafting: propensity matched analysis

INTRODUCTION

Minimally invasive extracorporeal circulation has developed with the aim of reducing the impact of the adverse effects associated with conventional extracorporeal circulation. The aim of this study was to compare outcomes for patients undergoing coronary artery bypass grafting using minimally invasive extracorporeal circulation with those performed using conventional extracorporeal circulation.

METHODS

A retrospective analysis was performed of patients undergoing minimally invasive extracorporeal circulation coronary artery bypass grafting at a single centre. 2:1 propensity matching was performed to identify control patients undergoing conventional extracorporeal circulation coronary artery bypass grafting. Outcomes were compared using univariate analysis.

RESULTS

A total of 354 patients were included in the study, with 118 patients undergoing minimally invasive extracorporeal circulation coronary artery bypass grafting. Patients were well matched on baseline characteristics. The mean logistic EuroSCORE was 3.95 ± 4.20. Operative times (3.31 ± 1.52 vs. 3.56 ± 0.73, p = 0.03) were significantly shorter in minimally invasive extracorporeal circulation cases. Patients who underwent surgery with minimally invasive extracorporeal circulation had significantly less 12-hour blood loss (322.3 ± 13.2 mL vs. 380.8 ± 15.2 mL, p < 0.01). Correspondingly, a significantly lower proportion of patients were transfused (25.8% vs. 36%, p = 0.04), and the mean number of red blood cells transfused was lower (0.45 ± 0.95 vs. 0.97 ± 2.13, p = 0.01). Similarly, the number of coagulation products administered was lower (0.161 ± 0.05 vs. 0.40 ± 0.09, p = 0.05). There was a significantly lower incidence of acute kidney injury (11.0% vs. 19.9%, p = 0.03). Minimally invasive extracorporeal circulation was associated with a £679.50 cost saving per patient.

DISCUSSION

Minimally invasive extracorporeal circulation for coronary artery bypass grafting is associated with a reduced requirement for blood transfusion, reduced incidence of acute kidney injury and a significant cost saving. Minimally invasive extracorporeal circulation should be considered as an adjunct for all patients undergoing coronary artery bypass grafting.

Inflammation and coagulation following minimally invasive extracorporeal circulation technologies

Minimally invasive extracorporeal perfusion technologies are based on the use of a minimally invasive extracorporeal circulation (MiECC) system. This includes a closed CPB circuit; biologically inert blood contact surfaces; reduced priming volume; a centrifugal pump; a membrane oxygenator; a heat exchanger; a cardioplegia system; a venous bubble trap/venous air removing device; and a shed blood management system. Some of these items, alone or in combination, are able to modify the blood activation usually elicited by cardiopulmonary bypass (CPB). The hemostatic system activation is less activated and lower degrees of thrombin generation and platelet activation have been found in numerous studies. Additionally, the reduced level of hemodilution plays an important role in preserving clot firmness after CPB with MiECC. These biochemical changes are reflected by a blood loss containment, a reduced need for allogeneic blood transfusions, and, in some studies, by a lower thromboembolic complications rate. The activation of the inflammatory cascade is in turn limited by MiECC, both directly (through a blunting of the contact-phase activation) and indirectly (through a limited thrombin generation, platelet activation, and consequent lower release of pro-inflammatory cytokines). The clinical consequences of this are mainly demonstrated by a lower rate of postoperative atrial fibrillation; other inflammation-derived outcomes appear favorably affected by MiECC (lung function, acute kidney injury) but the multi-factorial nature of these complications makes difficult to clearly attribute this pattern to a lower degree of inflammation. Overall, the existing body of evidence is in favor of MiECC with respect to standard CPB.

Coronary Artery Bypass Grafting with Arterial Conduits in the Elderly

Although improved long-term outcomes obtained with the use of arterial grafts for coronary revascularization in comparison with the traditional association of a single arterial and saphenous vein grafts have been demonstrated in the overall population, the efficacy of this newer technique in the elderly is difficult to prove because their shorter life expectancy due to advanced heart disease, associated with severe comorbidities. Moreover, more widespread use of this technique is limited by the concerns on the potential morbidity, particularly the longer time required to perform the operation and the possibility of deep sternal wound infection in case of bilateral internal thoracic artery harvesting due to the decreased blood supply to the sternum and surrounding tissues.The review of the recent literature indicates that the use of bilateral internal thoracic arteries in very elderly patients should not be considered routinely. It seems reasonable to avoid it in octogenarians in the presence of well-known predictors of sternal complications such as diabetes, morbid obesity, and severe chronic lung disease.There is also still controversy about the superiority of the radial artery over the saphenous vein graft as a second or third conduit for surgical myocardial revascularization, although the majority of recent studies seem to support more liberal use of the radial artery as second arterial conduit in the elderly. Although a clinical benefit of arterial graft revascularization cannot be formally excluded for elderly patients, the increased complexity of this technique suggests that careful clinical judgment is necessary to select grafts for individual patients.

Use of minimal invasive extracorporeal circulation in cardiac surgery: principles, definitions and potential benefits. A position paper from the Minimal invasive Extra-Corporeal Technologies international Society (MiECTiS)

Minimal invasive extracorporeal circulation (MiECC) systems have initiated important efforts within science and technology to further improve the biocompatibility of cardiopulmonary bypass components to minimize the adverse effects and improve end-organ protection. The Minimal invasive Extra-Corporeal Technologies international Society was founded to create an international forum for the exchange of ideas on clinical application and research of minimal invasive extracorporeal circulation technology. The present work is a consensus document developed to standardize the terminology and the definition of minimal invasive extracorporeal circulation technology as well as to provide recommendations for the clinical practice. The goal of this manuscript is to promote the use of MiECC systems into clinical practice as a multidisciplinary strategy involving cardiac surgeons, anaesthesiologists and perfusionists.

Coronary artery bypass grafting in octogenarians: only when percutaneous coronary intervention is not feasible?

PURPOSE OF REVIEW

The aim of this study was to review recent literature reporting the results of coronary revascularization by percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) in patients older than 80 years.

RECENT FINDINGS

The review of recent studies on octogenarians demonstrates a surgical CABG advantage in the case of patients with increasing baseline coronary risk, such as severe multivessel disease, chronic total occlusions, and left ventricular dysfunction. PCI seems to be more appropriate for less severe degree and distribution of coronary lesions, and for subgroups of patients with higher surgical risk, such as acute coronary syndromes, reoperations, malignancy, dementia, poor mobility, frailty, and serious comorbidities contraindicating extracorporeal circulation.

SUMMARY

It is not the case that CABG is indicated only when there are contraindications to PCI. CABG confers more benefit than PCI in patients with increasing baseline cardiac risk, in the absence of serious systemic diseases that can reasonably reduce their life expectancy.CABG and PCI, with proper selection, should be considered complementary rather than competitive procedures in the therapy of octogenarians affected by coronary artery disease.

Minimized extracorporeal circulation is improving outcome of coronary artery bypass surgery in the elderly

Advanced age is a known risk factor for morbidity and mortality after coronary artery bypass grafting (CABG). Minimized extracorporeal circulation (MECC) has been shown to reduce the negative effects associated with conventional extracorporeal circulation (CECC). This trial assesses the impact of MECC on the outcome of elderly patients undergoing CABG. Eight hundred and seventy-five patients (mean age 78.35 years) underwent isolated CABG using CECC (n=345) or MECC (n=530). The MECC group had a significantly shorter extracorporeal circulation time (ECCT), cross-clamp time and reperfusion time and lower transfusion needs. Postoperatively, these patients required significantly less inotropic support, fewer blood transfusions, less postoperative hemodialysis and developed less delirium compared to CECC patients. In the MECC group, intensive care unit (ICU) stay was significantly shorter and 30-day mortality was significantly reduced [2.6% versus 7.8%; p<0.001]. In conclusion, MECC improves outcome in elderly patients undergoing CABG surgery.