Clinical Relevance of Troponin T Profile Following Cardiac Surgery

Clinical impact of del Nido cardioplegia in adult cardiac surgery: A prospective randomized trial

OBJECTIVE

The study objective was to assess the benefits of del Nido cardioplegia compared with cold blood cardioplegia solution in terms of myocardial protection during adult cardiac surgery.

METHODS

A total of 474 adult patients undergoing coronary artery bypass grafting, heart valve surgery, thoracic aortic surgery, or combined procedures were randomized to the del Nido cardioplegia group (n = 234) or the cold blood cardioplegia solution group (n = 240) after provided informed consent. The primary end points assessed inotropic support requirements, severe cardiovascular events, and troponin trend within the first 48 hours of intensive care unit stay. Reperfusion arrhythmias, aortic crossclamp and cardiopulmonary bypass times, and other clinical perioperative variables were considered as secondary end points.

RESULTS

No statistically significant differences were found regarding postoperative inotropic support requirements or the incidence of severe cardiovascular events. The del Nido cardioplegia group showed a higher return to spontaneous sinus rhythm (P< .001), a lower number of defibrillation attempts (P< .001), and an earlier peak troponin value in the postoperative period. Peak blood glucose levels and intravenous insulin requirements were significantly lower in the del Nido cardioplegia group. We found no significant differences regarding aortic crossclamp or cardiopulmonary bypass time. We did observe a lower incidence of postoperative stroke in the del Nido cardioplegia group (2.6% vs 6.7%; P= .035).

CONCLUSIONS

del Nido cardioplegia can be used safely and with comparable outcomes compared with traditional cardioplegia solutions. Additional advantages over glycemic control, reperfusion arrhythmias, and its comfortable redosing interval make del Nido an interesting alternative for myocardial protection in adult cardiac surgery. A significant decrease in postoperative stroke will require further research to shed light on the results of this study. VIDEO ABSTRACT.

One-shot cardioplegia for minimally invasive mitral valve repair-a comparison of del Nido and Bretschneider Histidine-Tryptophan-Ketoglutarate solutions

BACKGROUND

Minimally invasive procedures are demanding in terms of cardioprotection. In many leading centres Bretschneider HTK solution is used for mitral valve surgery. The study was designed to provide comparison of the del Nido and Bretschneider HTK protocol.

METHODS

Patients who underwent minimally invasive mitral valve repair for primary mitral regurgitation and received single delivery of either del Nido (Group 1) or Bretschneider HTK cardioplegia (Group 2) were matched on basis of age, gender and length of the cross-clamp time. The groups were compared in terms of major adverse cardiac and cerebrovascular events (death, myocardial infarction, stroke), high sensitivity troponin T (hs-TnT) and creatine kinase- MB isoenzyme (CK-MB) release at 12 h and 24 h following the surgery, incidence of low cardiac output syndrome (LCOS), postoperative arrhythmia, transfusions and postoperative renal function.

RESULTS

Case control matching selected 38 pairs of patients. None of patients died, nor suffered from myocardial infarction or stroke. Troponin values did not differ at 12 h (median: 281.0 pg/mL vs 313.0 pg/mL; p = .38) and 24 h (median: 261.0 pg/mL vs 299.0 pg/mL; p = .54), as well as CK-MB at 12 h (median: 25.0 ng/mL vs 29.0 ng/mL; p = .31) and 24 h (median: 11.0 ng/mL versus 9.6 ng/mL; p = .46). Difference in occurrence of LCOS was insignificant (2 vs 7; 5.2% vs 18.4%; p =.15). No difference was shown in incidence of postoperative arrhythmia, transfusions and renal function.

CONCLUSIONS

Del Nido cardioplegia can be used safely as an alternative for Bretschneider HTK for minimally invasive mitral valve surgery.

Towards an improved definition of periprocedural myocardial infarction: The role of high-sensitivity cardiac troponins

In the past few years, many have disputed the optimal biomarker for confirming or ruling out a diagnosis of periprocedural myocardial infarction (PMI) and the optimal cut‐off concentrations to apply. In this issue of the Journal of Cardiac Surgery, Niclauss et al. performed a retrospective analysis of CK‐MB and high‐sensitivity cardiac troponin T (hs‐cTnT) dynamics and peak concentrations following different cardiac surgical interventions in 400 patients during a 2‐year period in a single center. The authors found that CK‐MB and hs‐cTnT predict PMI with a comparable diagnostic accuracy and discriminatory power >95%. They also attempted to propose an improved, more sensitive threshold of hs‐cTnT for PMI. Their findings could have implications for clinical practice, but more research is warranted to identify more appropriate cut‐offs. This could include hs‐cTnT release pattern, slope steepness, and changes. Ultimately, this could results in patient‐specific model, able to predict expected and abnormal ranges of hs‐cTnT release, enabling an improved and timely diagnosis of PMI.

Effects of peak time of myocardial injury biomarkers on mid-term outcomes of patients undergoing OPCABG

BACKGROUND

With the development of cardiac surgery techniques, myocardial injury is gradually reduced, but cannot be completely avoided. Myocardial injury biomarkers (MIBs) can quickly and specifically reflect the degree of myocardial injury. Due to various reasons, there is no consensus on the specific values of MIBs in evaluating postoperative prognosis. This retrospective study was aimed to investigate the impact of MIBs on the mid-term prognosis of patients undergoing off-pump coronary artery bypass grafting (OPCABG).

METHODS

Totally 564 patients undergoing OPCABG with normal courses were included. Cardiac troponin T (cTnT) and creatine kinase myocardial band (CK-MB) were assessed within 48 h before operation and at 6, 12, 24, 48, 72, 96 and 120 h after operation. Patients were grouped by peak values and peak time courses of MIBs. The profile of MIBs and clinical variables as well as their correlations with mid-term prognosis were analyzed by univariable and multivariable Cox regression models.

RESULT

Continuous assessment showed that MIBs increased first (12 h after surgery) and then decreased. The peak cTnT and peak CK-MB occurred within 24 h after operation in 76.8% and 67.7% of the patients respectively. No significant correlation was found between CK-MB and mid-term mortality. Delayed cTnT peak (peak cTnT elevated after 24 h after operation) was correlated with lower creatinine clearance rate (69.36 ± 21.67 vs. 82.18 ± 25.17 ml/min/1.73 m²), body mass index (24.35 ± 2.58 vs. 25.27 ± 3.26 kg/m²), less arterial grafts (1.24 ± 0.77 vs. 1.45 ± 0.86), higher EuroSCORE II (2.22 ± 1.12 vs.1.72 ± 0.91) and mid-term mortality (26.5 vs.7.9%). Age (HR: 1.067, CI: 1.006-1.133), left ventricular ejection fraction (HR: 0.950, CI: 0.910-0.993), New York Heart Association score (HR: 1.839, CI: 1.159-2.917), total venous grafting (HR: 2.833, CI: 1.054-7.614) and cTnT peak occurrence within 24 h (HR: 0.362, CI: 0.196-0.668) were independent predictors of mid-term mortality.

CONCLUSION

cTnT is a better indicator than CK-MB. The peak value and peak occurrence of cTnT are related to mid-term mortality in patients undergoing OPCABG, and the peak phases have stronger predictive ability.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2000033850. Registered 14 June 2020, http://www.chictr.org.cn/edit.aspx?pid=55162&htm=4 .

Evaluation of Biomarkers in Critical Care and Perioperative Medicine: A Clinician’s Overview of Traditional Statistical Methods and Machine Learning Algorithms

Interest in developing and using novel biomarkers in critical care and perioperative medicine is increasing. Biomarkers studies are often presented with flaws in the statistical analysis that preclude them from providing a scientifically valid and clinically relevant message for clinicians. To improve scientific rigor, the proper application and reporting of traditional and emerging statistical methods (e.g., machine learning) of biomarker studies is required. This Readers' Toolbox article aims to be a starting point to nonexpert readers and investigators to understand traditional and emerging research methods to assess biomarkers in critical care and perioperative medicine.

Detecting patients with PMI post-CABG based on cardiac troponin-T profiles: A latent class mixed modeling approach

BACKGROUND

Diagnosis of perioperative myocardial infarction (PMI) after coronary artery bypass grafting (CABG) is fraught with complexity since it is primarily based on a single cut-off value for cardiac troponin (cTn) that is exceeded in over 90% of CABG patients, including non-PMI patients. In this study we applied an unsupervised statistical modeling approach to uncover clinically relevant cTn release profiles post-CABG, including PMI, and used this to improve diagnostic accuracy of PMI.

METHODS

In 624 patients that underwent CABG, cTnT concentration was serially measured up to 24 h post aortic cross clamping. 2857 cTnT measurements were available to fit latent class linear mixed models (LCMMs).

RESULTS

Four classes were found, described by: normal, high, low and rising cTnT release profiles. With the clinical diagnosis of PMI as golden standard, the rising profile had a diagnostic accuracy of 97%, compared to 83% for an optimally chosen cut-off and 21% for the guideline recommended cut-off value.

CONCLUSION

Clinically relevant subgroups, including patients with PMI, can be uncovered using serially measured cTnT and a LCMM. The LCMM showed superior diagnostic accuracy of PMI. A rising cTnT profile is potentially a better criterion than a single cut-off value in diagnosing PMI post-CABG.