Myocardial preservation methods in isolated minimal invasive mitral valve surgery: Society of Thoracic Surgeons (STS) database outcomes

Comparison of modified Del Nido and Custodiol® cardioplegia in minimally invasive mitral valve surgery

OBJECTIVES

In this study, we evaluated if modified Del Nido cardioplegia delivers comparable cardiac protection in comparison to Custodiol® in patients undergoing isolated minimally invasive mitral valve repair.

METHODS

From January 2018 to October 2021, all patients undergoing non-emergent isolated minimally invasive mitral valve repair were included in this study. The cardioplegia was chosen at the surgeons' discretion. The primary end points of this study were peak postoperative cardiac enzyme levels. Secondary end points were in-hospital mortality, hospital stay, occurrence of cardiac arrhythmias, pacemaker implantations, postoperative lactate and sodium levels and postoperative incidence of renal failure requiring dialysis.

RESULTS

A total of 355 patients were included in this study. The mean age of patients was 57. After propensity score matching, a total of 156 pairs were identified. There was no difference in cross-clamp time between both groups. Postoperative creatine kinase levels were higher in patients receiving Custodiol on the 1st and 2nd postoperative days. Creatine kinase isoenzyme MB levels were higher in patients receiving Custodiol on the 2nd postoperative day (0.5 ± 0.2 vs 0.4 ± 0.1 µmol/l s; P < 0.001). Postoperative Troponin T concentrations were similar between both groups. Maximum lactate concentrations were higher in patients receiving Custodiol on the day of surgery (2.4 ± 1.9 vs 2.0 ± 1.1 mmol/l; P = 0.04). The overall hospital stay was longer in patients receiving Del Nido cardioplegia (10.6 ± 3.2 vs 8 ± 4.1 days; P < 0.01).

CONCLUSIONS

Modified Del Nido cardioplegia based on Ionosteril® solution offers equivalent protection compared to Custodiol for isolated minimally invasive mitral valve repair.

Del Nido cardioplegia or potassium induces Nrf2 and protects cardiomyocytes against oxidative stress

Open heart surgery is often an unavoidable procedure for the treatment of coronary artery disease. The procedure-associated reperfusion injury affects postoperative cardiac performance and long-term outcomes. We addressed here whether cardioplegia essential for cardiopulmonary bypass surgery activates Nrf2, a transcription factor regulating the expression of antioxidant and detoxification genes. With commonly used cardioplegic solutions, high K+, low K+, Del Nido (DN), histidine-tryptophan-ketoglutarate (HTK), and Celsior (CS), we found that DN caused a significant increase of Nrf2 protein in AC16 human cardiomyocytes. Tracing the ingredients in DN led to the discovery of KCl at the concentration of 20-60 mM capable of significant Nrf2 protein induction. The antioxidant response element (ARE) luciferase reporter assays confirmed Nrf2 activation by DN or KCl. Transcriptomic profiling using RNA-seq revealed that oxidation-reduction as a main gene ontology group affected by KCl. KCl indeed elevated the expression of classical Nrf2 downstream targets, including TXNRD1, AKR1C, AKR1B1, SRXN1, and G6PD. DN or KCl-induced Nrf2 elevation is Ca2+ concentration dependent. We found that KCl decreased Nrf2 protein ubiquitination and extended the half-life of Nrf2 from 17.8 to 25.1 mins. Knocking out Keap1 blocked Nrf2 induction by K+. Nrf2 induction by DN or KCl correlates with the protection against reactive oxygen species generation or loss of viability by H2O2 treatment. Our data support that high K+ concentration in DN cardioplegic solution can induce Nrf2 protein and protect cardiomyocytes against oxidative damage.NEW & NOTEWORTHY Open heart surgery is often an unavoidable procedure for the treatment of coronary artery disease. The procedure-associated reperfusion injury affects postoperative cardiac performance and long-term outcomes. We report here that Del Nido cardioplegic solution or potassium is an effective inducer of Nrf2 transcription factor, which controls the antioxidant and detoxification response. This indicates that Del Nido solution is not only essential for open heart surgery but also exhibits cardiac protective activity.

Comparison of Bretschneider HTK cardioplegia solution and blood cardioplegia in terms of postoperative results in patients who underwent isolated supracoronary ascending aortic replacement

INTRODUCTION

Cardiac arrest with cardioplegia is the most common and reliable method of myocardial protection in cardiac surgery, but there is no definite consensus on the use of different types of cardioplegia. Two of the commonly used types of cardioplegia are Bretschneider histidine-tryptophan-ketoglutarate solution (Custodiol) and conventional blood cardioplegia. In this study, Custodiol solution and conventional blood cardioplegia used in patients with type A aortic dissection who underwent supracoronary ascending aortic replacement were aimed to be compared in terms of postoperative results.

METHODS

70 patients with type A aortic dissection who underwent supracoronary ascending aortic replacement in our clinic between January 2011 - October 2020 were included. Patients were divided into two groups, blood cardioplegia group (n = 48) and Custodiol group (n = 22) and they were compared regarding preoperative, perioperative and postoperative variables.

RESULTS

There was no significant difference between cardiopulmonary bypass time and cross-clamp time (p = 0.17 and p = 0.16, respectively). Mechanical ventilator weaning time, intensive care unit stay and hospital stay were shorter in Custodiol group (p = 0.04,p = 0.03 and p = 0.05, respectively). While inotropic support need was higher in the blood cardioplegia group (p = 0.001), there was no significant difference in terms of mortality, arrhythmia, neurological complications and renal complications.

CONCLUSIONS

Our results show that Custodiol cardioplegia solution may be superior to blood cardioplegia in reducing mechanical ventilation weaning period, intensive care and hospital stay, and reducing the use of inotropic agents in patients with type A aortic dissection undergoing supracoronary ascending aorta replacement.

Single-Dose St. Thomas Versus Custodiol® Cardioplegia for Right Mini-thoracotomy Mitral Valve Surgery

OBJECTIVE

Custodiol® and St. Thomas cardioplegia are widely employed in mini-thoracotomy mitral valve (MV) operations. One-dose of the former provides 3 h of myocardial protection. Conversely, St. Thomas solution is usually reinfused every 30 min and safety of single delivery is unknown. We aimed to compare single-shot St. Thomas versus Custodiol® cardioplegia.

METHODS

Primary endpoint of the prospective observational study was cardiac troponin T level at different post-operative time-points. Propensity-weighted treatment served to adjust for confounding factors.

RESULTS

Thirty-nine patients receiving St. Thomas were compared with 25 patients receiving Custodiol® cardioplegia; cross-clamping always exceeded 45 min. No differences were found in postoperative markers of myocardial injury. Ventricular fibrillation at the resumption of electric activity was more frequent following Custodiol® cardioplegia (P = .01).

CONCLUSION

Effective myocardial protection exceeding 1 h of ischemic arrest can be achieved with a single-dose St. Thomas cardioplegia in selected patients undergoing right mini-thoracotomy MV surgery.

At the Crossroads of Minimally Invasive Mitral Valve Surgery—Benching Single Hospital Experience to a National Registry: A Plea for Risk Management Technology

Almost 30 years after the first endoscopic mitral valve repair, Minimally Invasive Mitral Valve Surgery (MIMVS) has become the standard at many institutions due to optimal clinical results and fast recovery. The question that arises is can already good results be further improved by an Institutional Risk Management Performance (IRMP) system in decreasing risks in minimally invasive mitral valve surgery (MIMVS)? As of yet, there are no reports on IRMP and learning systems in the literature. (2) Methods: We described and appraised our five-year single institutional experience with MIMVS in isolated valve surgery included in the Netherlands Heart Registry (NHR) and investigated root causes of high-impact complications. (3) Results: The 120-day and 12-month mortality were 1.1% and 1.9%, respectively, compared to the average of 4.3% and 5.3% reported in the NHR. The regurgitation rate was 1.4% compared to 5.2% nationwide. The few high-impact complications appeared not to be preventable. (4) Discussion: In MIMVS, freedom from major and minor complications is a strong indicator of an effective IRMP but remains concealed from physicians and patients, despite its relevance to shared decision making. Innovation adds to the complexity of MIMVS and challenges surgical competence. An IRMP system may detect and control new risks earlier. (5) Conclusion: An IRMP system contributes to an effective reduction of risks, pain and discomfort; provides relevant input for shared decision making; and warrants the safe introduction of new technology. Crossroads conclusions: investment in machine learning and AI for an effective IRMP system is recommended and the roles for commanding and operating surgeons should be considered.

In search of optimal cardioplegia for minimally invasive valve surgery

Cardioplegic solutions are used in cardiac surgery to achieve controlled cardiac arrest during operations, making surgery safer. Cardioplegia can either be blood or crystalloid based, with perceived pros and cons of each type. Whilst it is known that cardioplegia causes cardiac arrest, there is debate over which cardioplegic solution provides the highest degree of myocardial protection during arrest. Myocardial damage is measured post-operatively by biomarkers such as serum TnT, TnI or CK-MB. It is known that the outcomes of minimally invasive valve surgery are comparable to full sternotomy valve operations. Despite there being a wide diversity in use of different cardioplegic solutions across the world, this comprehensive literature review found no superiority of one cardioplegic solution over the other for myocardial protection during minimally invasive valve procedures.