Cardioprotection in cardiovascular surgery

Abstract

Since the invention of cardiopulmonary bypass, cardioprotective strategies have been investigated to mitigate ischemic injury to the heart during aortic cross-clamping and reperfusion injury with cross-clamp release. With advances in cardiac surgical and percutaneous techniques and post-operative management strategies including mechanical circulatory support, cardiac surgeons are able to operate on more complex patients. Therefore, there is a growing need for improved cardioprotective strategies to optimize outcomes in these patients. This review provides an overview of the basic principles of cardioprotection in the setting of cardiac surgery, including mechanisms of cardiac injury in the context of cardiopulmonary bypass, followed by a discussion of the specific approaches to optimizing cardioprotection in cardiac surgery, including refinements in cardiopulmonary bypass and cardioplegia, ischemic conditioning, use of specific anesthetic and pharmaceutical agents, and novel mechanical circulatory support technologies. Finally, translational strategies that investigate cardioprotection in the setting of cardiac surgery will be reviewed, with a focus on promising research in the areas of cell-based and gene therapy. Advances in this area will help cardiologists and cardiac surgeons mitigate myocardial ischemic injury, improve functional post-operative recovery, and optimize clinical outcomes in patients undergoing cardiac surgery.

Keywords: Cardioprotection; Cardiopulmonary bypass; Cardiovascular surgery.

Fig. 1

Mechanisms and contributors to myocardial injury in cardiac surgery. Cardiac surgery involving cardioplegic arrest and reperfusion leads to a variety of insults to the myocardium including generation of reactive oxygen species, microvascular dysfunction, abnormal calcium signaling, altered metabolism, and increased inflammation

Fig. 2

Technical considerations of cardioplegia administration. Several technical considerations should be considered when administering cardioplegia in the setting of cardiopulmonary bypass (CPB). Considerations specific to antegrade cardioplegia include presence of coronary artery disease, aberrant coronary arterial anatomy, presence of aortic regurgitation. Considerations specific to retrograde cardioplegia presence of aberrant venous anatomy and awareness of inadequate right ventricular (RV) perfusion. Both antegrade and retrograde cardioplegia may provide suboptimal protection in the setting of left ventricular (LV) hypertrophy

Fig. 3

Approaches to cardioprotection in cardiac surgery. Several strategies have been investigated and used to optimize cardioprotection in the setting of cardiac surgery. Cardiopulmonary bypass and cardioplegia is the foundation of modern cardiac surgery and allowing for a bloodless field while protecting the heart from ischemic injury. Mechanical circulatory support is a rapidly evolving area that allows for support of the heart and coronary and systemic perfusion in and out of the operating room. Additional areas of investigation in optimization of cardioprotection have been performed in the areas of ischemic conditioning and with regard to various anesthetic and pharmaceutical agents

Fig. 4

Future directions in myocardial protection. Figure shows major four areas of investigation in myocardial protection including mitochondrial transplantation, extracellular vesicles, stem cells and gene therapy. The figure includes the most common source, the therapeutic substrate, and the most common method of administration