Terminal warm blood cardioplegia in mitral valve replacement: prospective study

Can heartbeat recovery be improved with terminal non-cardioplegic warm blood perfusion prior to aortic unclamping in single-clamp technique coronary artery bypass surgery? A randomized controlled trial

BACKGROUND

The objective of this study is to investigate whether the use of antegrade perfusion with terminal non-cardioplegic warm blood (TNWB) before aortic unclamping in single-clamp technique coronary artery bypass has a positive impact on intraoperative heartbeat recovery.

METHODS

Between December 2022 and May 2023, 40 consecutive patients undergoing coronary artery bypass using single-clamp technique were randomized into one of two groups: the TNWB group received an antegrade perfusion with TNWB before removing the aortic cross-clamp (n = 20), while the control group did not receive (n = 20). The time intervals between coronary perfusion and the onset of the first heartbeats and sinus rhythms, occurrences of spontaneous sinus rhythm, intraoperative defibrillation requirements, as well as postoperative CK-MB and troponin T levels were recorded and subjected to analysis.

RESULTS

In the TNWB group, the median onset of the first heartbeats after the initiation of coronary perfusion was 34 s (4-100), while in the control group, it was 90 s (15-340) (p < 0.001). The median onset of the sinus rhythms was 100 s (28-290) in the TNWB group and was 132 s (45-350) in the control group (p = 0.023). The occurrence of intraoperative arrhythmias was 15% in the TNWB group compared to 50% in the control group (p = 0.018), and the incidence for internal defibrillation was 5% in the TNWB group and was 30% in the control group (p = 0.037). The TNWB group showed the median CK-MB levels at 6 h postoperative was 14.10 ng/mL (9.78-19.26), compared to 18.31 ng/mL (13.98-23.80) in the control group (p = 0.045).

CONCLUSIONS

During single clamp coronary artery bypass, administration TNWB into the aortic root before aortic unclamping has the potential to enhance heartbeat recovery, as evidenced by the shortened time to the initial heartbeat and the establishment of sinus beats following coronary perfusion.

TRIAL REGISTRATION

Trial registration number (Study ID): TCTR20231002003.

Myocardial Protection With Different Cardioplegia in Adult Cardiac Surgery: A Network Meta-Analysis

AIM

Cardioplegia is one of the most studied fields of myocardial protection during cardiac surgery. However, the most effective cardioplegia for protection in adult cardiac surgery remains unknown.

METHOD

PubMed and other databases were searched and a network meta-analysis with a Bayesian framework was performed. The primary outcomes were the serum concentrations of creatine kinase-myocardial band (CK-MB), cardiac troponin I, and cardiac troponin T (cTnT) at four time points. Several clinical outcomes were evaluated, including low output syndrome, myocardial infarction, and risk of early mortality. All studies that involved crystalloid cardioplegia without reference to St Thomas cardioplegia or histidine-tryptophan-ketoglutarate solution, and if the cardioplegia was used at a temperature between 4°C and 16°C were classified as cold crystalloid (cCCP) or cold blood cBCP cardioplegia. Warm blood cardioplegia (wBCP) was defined as the blood cardioplegia used at a temperature between 32°C and 37°C.

RESULTS

Forty-seven (47) studies with a total of 4,175 patients were included. Seven (7) cardioplegia solutions were used, including cold CCP or BCP, del Nido solution, histidine-tryptophan-ketoglutaratesolution, St Thomas cardioplegia, wBCP and warm terminal blood cardioplegia (wtBCP). The serum concentrations of CK-MB at 2 hours (mean difference [MD], 213.56; 95% confidence interval [CI], -25.79 to -1.59) and cTnT at 24 hours of wBCP (MD, -1.50; 95% CI, -2.69 to -0.31) were significantly lower than that of cCCP. There were no significant differences in other outcomes of these six cardioplegia solutions, when compared to cCCP.

CONCLUSIONS

The seven cardioplegia solutions analysed had similar myocardial protective effects after adult cardiac surgery, although wBCP had a lower CK-MB at 2 hours and lower cTnT at 24 hours.