Microplegia in cardiac surgery: Systematic review and meta-analysis.

BACKGROUND

Consensus on the optimum choice of cardioplegia remains elusive. One possibility that has been suggested to have beneficial properties is microplegia, a cardioplegia of reduced crystalloid volume. The aim of this meta-analysis is to comprehensively investigate microplegia against a range of clinical outcomes.

METHODS

To identify potential studies, systematic searches were carried out in four databases (eg, Pubmed, EMBASE). The search strategy included the key concepts of "microplegia" OR "mini-cardioplegia" OR "miniplegia" AND "cardiac surgery." This was followed by a meta-analysis investigating: mortality, crystalloid volume; cardiopulmonary bypass time; cross-clamp time; intra-aortic balloon pump use; spontaneous heartbeat recovery; inotropic support; low cardiac output syndrome; myocardial infarction; acute renal failure; atrial fibrillation, reoperation for bleeding; creatine kinase myocardial band (CK-MB); intensive care unit (ICU) time and hospital stay.

RESULTS

Eleven studies comprising 5798 participants were analyzed. Microplegia used a lower volume of crystalloids and led to a higher spontaneous return of heartbeat, odds ratio (OR) 4.271 (95% confidence intervals [CIs]: 1.935, 9.423; I2  = 76.57%; P < .001) and a lower requirement for inotropic support, OR: 0.665 (95% CI: 0.47, 0.941; I2  = 3.53%; P = .021). Microplegia was also associated with a lower CK-MB release, mean difference (MD) -6.448 ng/mL (95% CI: -9.386, -3.511; I2  = 0%; P < .001) and a shorter ICU stay, MD: -0.411 days (95% CI: -0.812, -0.009; I2  = 17.65%; P = .045). All other comparisons were nonsignificant.

CONCLUSIONS

Microplegia has similar effects to other types of cardioplegia and is beneficial with regard to spontaneous return of heartbeat, inotropic support, ICU stay, and CK-MB release.