Microplegia vs 4:1 Blood Cardioplegia: Effectiveness and Cost Savings in Complex Cardiac Operations.

Background: Microplegia has been studied during isolated coronary artery bypass grafting and valve surgery but not in more complex operations. Objectives of this study were to demonstrate safety and effectiveness of microplegia relative to Buckberg cardioplegia during these operations.

Methods: From January 2012 to January 2017, 242 patients underwent multicomponent operations with simplified microplegia delivered via syringe pump and 10,512 with modified Buckberg cardioplegia. Operations included aortic root, arch, or ascending aorta replacement in 424 (94%) patients, aortic valve surgery in 324 (72%) patients, and concomitant coronary artery bypass grafting in 47 (10%) patients. Outcomes were compared in 226 propensity-matched pairs.

Results: There was no difference in median postoperative troponin T between groups after adjusting for aortic clamp time. Microplegia patients received significantly less crystalloid with their cardioplegia (mean 27 ± 8.0 mL/operation vs 735 ± 357 mL/operation; P < .001) and had lower peak intraoperative glucose (196 ± 40 mg/dL vs 248 ± 69 mg/dL; P < .001). Microplegia and Buckberg groups had similar in-hospital mortality (2.7% [n = 6] vs 2.2% [n = 5]; P = .8), stroke (2.2% [n = 5] vs 3.6% [n = 8]; P = .4), renal failure (8% [n = 18] vs 5.8% [n = 13]; P = .4), prolonged ventilation (23% [n = 51] vs 24% [n = 54]; P = .7), median postoperative length of stay (both 8.1 days; P > .9), and median red cell units administered to patients requiring transfusion (4 units vs 3 units; P = .14). The mean cost of cardioplegia per case with microplegia was 1/26th that of Buckberg cardioplegia.

Conclusions: Our simplified microplegia technique offers several advantages over Buckberg cardioplegia without compromising myocardial protection or safety in complex, multicomponent operations with extended aortic clamp times.