HTK versus multidose cardioplegias for myocardial protection in adult cardiac surgery: A meta-analysis

Comparison of "Huaxi-1" or "histidine-tryptophan-ketoglutarate" cardioplegia in an animal model

Background

Using a pig model of cardiopulmonary bypass, we compared outcomes after cardioplegia either with our in-house "Huaxi-1" solution containing natural blood and crystalloid or with the entirely crystalloid, commercially available "histidine-tryptophan-ketoglutarate" solution.

Methods

Cardiopulmonary bypass was established in 12 healthy male pigs, who were randomized to receive a single dose of either Huaxi-1 or entirely crystalloid. All animals were then subjected to whole-heart ischemia for 90 min, followed by 2 h of reperfusion, after which myocardial injury was assessed in terms of cardiac function, myocardial pathology and levels of biomarkers in plasma, while levels of high-energy phosphate in myocardium were assayed using liquid chromatography.

Results

Animals given Huaxi-1 cardioplegia required significantly less time to be weaned off bypass, they received significantly lower doses of norepinephrine, and they showed significantly higher levels (mean ± SD) of adenosine triphosphate (14 ± 4 vs. 8 ± 2 µg/mg, P = 0.005), adenosine diphosphate (16 ± 2 vs. 13 ± 2 µg/mg, P = 0.046), and total adenine nucleotide (37 ± 4 vs. 30 ± 3 µg/mg, P = 0.006) in myocardium after 2 h of reperfusion. They also showed less severe bleeding, edema and injury to mitochondria and myofibers in myocardium. The two groups did not differ significantly in doses of inotropic drugs received, cardiac output or levels of biomarkers in plasma.

Conclusions

In this animal model of healthy hearts subjected to 90 min of ischemia, Huaxi-1 cardioplegia may be superior to entirely crystalloid cardioplegia for promoting energy generation and attenuating ischemia/reperfusion injury in myocardium.

Comparison of Single-Dose Cardioplegia in Valvular Heart Surgery: Lactated Ringer's-Based del Nido vs. Histidine-Tryptophan-Ketoglutarate Cardioplegia Solution

INTRODUCTION

This study evaluated myocardial protection and clinical outcomes when using lactated Ringer's solution as the base solution for del Nido cardioplegia compared with histidine-tryptophan-ketoglutarate (HTK) solution in valvular surgery.

METHODS

From January 2017 to May 2018, 71 adult patients who underwent valvular surgery with del Nido cardioplegia (n=37) or HTK cardioplegia (n=34) were retrospectively analyzed.

RESULTS

Patients' characteristics were comparable between groups. Postoperative peak troponin T levels were similar. The del Nido group had a decreased incidence of ventricular fibrillation after aortic cross-clamp removal (13.51 vs. 55.88%; P<0.001), lower total volume of cardioplegia administered (1,000 [1,000, 1,250] vs. 1,800 [1,500, 2,000] mL; P<0.001), shorter hospital stay (6 [5, 8] vs. 7 [6, 10] days; P=0.03), and less postoperative red cell transfusion (34.29 vs. 61.11%; P=0.024). There is no difference in aortic cross-clamping time, postoperative change in left ventricular ejection fraction, intensive care unit stay, duration of inotropic support, new onset of atrial fibrillation, in-hospital mortality, complications, and three-year overall survival rate.

CONCLUSION

Lactated Ringer's-based del Nido cardioplegia can be safely used for valvular surgery with acceptable clinical outcomes compared to HTK cardioplegia.

Cardioplegia in Open Heart Surgery: Age Matters

INTRODUCTION

Cardioplegia is a pharmacological approach essential for the protection of the heart from ischemia-reperfusion (I-R) injury. Over the years, numerous cardioplegic solutions have been developed, with each cardioplegic approach having its advantages and disadvantages. Cardioplegic solutions can be divided into crystalloid and blood cardioplegic solutions, and an experienced surgeon chooses the type of solution based on the individual needs of patients in order to provide optimal heart protection. Importantly, the pediatric immature myocardium is structurally, physiologically, and metabolically different from the adult heart, and consequently its needs to achieve cardioplegic arrest strongly differ. Therefore, the present review aimed to provide a summary of the cardioplegic solutions available to pediatric patients with a special focus on emphasizing differences in heart injury after various cardioplegic solutions, the dosing strategies, and regimens.

MATERIAL AND METHODS

The PubMed database was searched using the terms cardioplegia, I-R, and pediatric population, and studies that investigated the influence of cardioplegic strategies on markers of cardiac muscle damage were further analyzed in this review.

CONCLUSIONS

A large body of evidence suggested more prominent benefits achieved with blood compared to those with crystalloid cardioplegia in pediatric myocardium preservation. However, standardized and uniform protocols have not been established so far, and an experienced surgeon chooses the type of cardioplegia solution based on the individual needs of patients, while the severity of myocardial damage strongly depends on the type and duration of the surgical procedure, overall patient condition, and presence of comorbidities, etc.

Theoretical and Practical Aspects in the Use of Bretschneider Cardioplegia

The race for an ideal cardioplegic solution has remained enthusiastic since the beginning of the modern cardiac surgery era. The Bretschneider solution, belonging to the “intracellular cardioplegic” group, is safe and practical in myocardial protection during ischemic time. Over time, some particular concerns have arisen regarding the effects on cardiac metabolism and postoperative myocardial functioning. This paper reviews the most important standpoints in terms of theoretical and practical analyses.

Histidine-tryptophan-ketoglutarate solution versus multidose cardioplegia for myocardial protection in cardiac surgeries: a systematic review and meta-analysis

Background

Surgical procedures in the heart requires protection of the heart from ischemia–reperfusion injury. Cardioplegia is the primary myocardial protective method in use. Histidine–tryptophan–ketoglutarate (HTK) solution is an intracellular cardioplegic solution that was initially used to preserve organs for transplantation.

Methods

A systematic electronic search was conducted in July 2021, in four databases; PubMed, Scopus, Web of Science, and Cochrane Library for eligible randomized controlled trials. The results were screened and the eligible trials were identified. Thereafter, the relevant data were extracted and pooled as mean difference or risk ratio, and 95% confidence interval in an inverse variance method using RevMan software.

Results

This review included 12 trials (n = 1327). HTK solution has resulted significantly in shorter intensive care unit stay (MD = − 0.09; 95% CI [− 0.15, − 0.03], p = 0.006), and shorter hospital stay (MD = − 0.51; 95% CI [− 0.71, − 0.31], p < 0.00001). Moreover, the patients who received the HTK solution had significantly lower levels of creatine kinase (after 4–7 h (MD = − 157.52; 95% CI [− 272.31, − 42.19], p = 0.007), and 24 h (MD = − 136.62; 95% CI [− 267.20, − 6.05], p = 0.04)), as well as creatine kinase muscle brain band (after 44–48 h (MD = − 3.35; 95% CI [− 5.69, − 1.02], p = 0.005)).

Conclusion

HTK solution had the same efficacy and safety as other cardioplegic solutions in most of the clinical parameters. Furthermore, the solution showed superiority in fastening the recovery and protecting the myocardium at the biochemical level. HTK solution provides longer myocardial protection; therefore, it limits surgical interruption. HTK solution can be used as an alternative to the currently used cardioplegic solutions.