Minimal Extracorporeal Circulation and Microplegia in the Setting of Urgent Coronary Artery Bypass Grafting

Background: We aimed to analyse the performance of minimal invasive extracorporeal circulation (MiECC) concomitantly with Microplegia, in patients with recent myocardial infarction (MI) undergoing urgent coronary artery bypass grafting (CABG) surgery. Methods: We included patients with a recent MI (≤7 days) undergoing isolated CABG surgery using MiECC. The primary endpoint was a major cardiovascular or cerebrovascular event (MACCE). In a secondary analysis, we compared our institutional Microplegia concept with the use of a crystalloid single-shot cardioplegic solution. Results: In total, 139 patients (mean ± standard deviation (SD) age 66 ± 10 years) underwent urgent CABG surgery using Microplegia; 55% (n = 77) of the patients had an acute MI within 1−7 days preoperatively; 20% (n = 28) had an acute MI within 6−24 h; and 24% (n = 34) had an acute MI within <6 h preoperatively. The number of distal anastomoses was a geometric mean of 4 (95% confidence interval 3−4). The MACCE and in-hospital mortality were 7% (n = 10) and 1% (n = 2), respectively. The results were confirmed in a secondary analysis comparing Microplegia with crystalloid cardioplegic solution (n = 271). Conclusion: The use of MiECC with Microplegia in urgent CABG surgery is feasible and safe and provides a straight-forward intraoperative setting. Therefore, it can also be considered to retain the benefits of MiECC in urgent CABG surgery.

Clinical implementation of a novel myocardial protection pathway in coronary artery bypass surgery with minimal extracorporeal circulation

INTRODUCTION

The aim of this study was to report the clinical implementation of the joint use of the Myocardial Protection System (MPS^®) and the minimal extracorporeal circulation system (MiECC), in conjunction with an institutionally refined dose/volume-dependent microplegia in coronary artery bypass grafting (CABG).

METHODS

Patients with isolated CABG surgery were included. The final protocol to achieve cardioplegic arrest consisted of warm blood cardioplegia with 20 mmol potassium (K), 1.6 g magnesium (Mg) and 40 mg lidocaine per liter (L) blood. We prospectively collected intra- and postoperative data to monitor and validate this novel approach.

RESULTS

Eighty patients were operated accordingly. Mean (SD) aortic clamping time and extracorporeal perfusion time were 67.5 (22.6) and 101.1 (31.9) minutes, respectively. Failure to induce cardiac arrest was seen in six patients at the early stage of refinement of the formula. Median (IQR) high -sensitivity cardiac troponin T (hs-cTnT) on the first postoperative day (POD) and peak hs-cTnT were 262.5 ng/L (194.3-405.8) and 265.5 ng/L (194.3-405.8), respectively. Median (IQR) creatine kinase-myocardial type (CK-MB) on POD 1 and peak CK-MB were 14.2 µg/L (10.5-22.7) and 14.2 µg/L (10.7-23.2), respectively. Median (IQR) creatine kinase (CK) on POD 1 and peak CK were 517.5 U/L (389.3-849.8) and 597.5 U/L (455.0-943.0), respectively. No patient died during hospitalization.

CONCLUSIONS

The combination of this cardioplegic formula with MPS^® and MiECC in CABG was safe and feasible. With the final chemical makeup, cardiac arrest was reliably achieved. Remarkably low postoperative cardiac markers indicate shielded cardiac protection during surgery.