Modified whole blood microplegia in high-risk patients

Numerous studies have documented the safety of whole blood cardioplegia on clinical outcomes after cardiac surgery. However, there is a paucity of studies investigating the outcomes of whole blood microplegia after cardiac surgery. Our protocol of whole blood microplegia includes removal of the crystalloid portion and utilizing the Quest Myocardial Protection System, for delivery of del Nido cardioplegia additives in whole blood. This study sought to evaluate the effects of whole blood microplegia on clinical outcomes, following cardiac surgery, in high-risk cardiac surgery patients.

Between February 2016 and December 2017, 131 high-risk patients underwent cardiac surgery operations, utilizing whole blood microplegia and were compared with a contemporaneous control group of 236 low-risk patients. High-risk patients included those who underwent combined coronary artery bypass grafting (CABG) and valve repair or replacement, double-valve surgery, triple-valve repair or replacement, and patients with ejection fraction < 40%. Multivariable logistic regression analysis was performed to identify independent risk factors of mortality after cardiac surgery.

Operative mortality was 7% for high-risk and 0% for low-risk patients (P < 0.001). Of those patients, five had isolated CABG (two had emergent CABG), two had double-valve surgery, two had combined valve/CABG. In multivariate analysis, high-risk classification (odds ratio = 3.66, 95% confidence intervals = 1.04-12.9, P = 0.04), emerged as an independent predictor of operative mortality.

Whole blood microplegia, is a novel myocardial protection strategy that can be applied in high-risk cardiac surgery patients and prolonged operations, requiring cardioplegic arrest with acceptable early clinical outcomes.