Prognostic Value of Early Postoperative Troponin T in Patients Undergoing Coronary Artery Bypass Grafting

How to harvest the left internal mammary artery-a randomized controlled trial

OBJECTIVES

It is uncertain whether Thunderbeat has a place in harvesting the left internal mammary artery (LIMA) and whether skeletonization is superior to pedicle-harvested LIMA. Some investigations have shown improved flowrates in the skeletonized graft. The aim of this study was to compare 3 groups of harvesting techniques: Pedicled, surgical skeletonized and skeletonized with Thunderbeat in terms of flow rates in the LIMA and postoperative in-hospital outcomes.

METHODS

Patients undergoing coronary artery bypass grafting with the LIMA to the anterior descending artery were randomized to pedicled (n = 56), surgical skeletonized (n = 55) and skeletonized with Thunderbeat (n = 54). Main outcomes were blood flow and pulsatility index in the graft.

RESULTS

No statistical difference between groups regarding flow in LIMA or pulsatility index. Similarly, no difference in postoperative bleeding or days of hospitalization. The duration of harvesting was faster for the pedicled technique compared with surgical skeletonized and skeletonized with Thunderbeat [mean total min: pedicled 20.2 min standard deviation (SD) ± 5.4; surgical skeletonized 28.6 min SD ± 8.7; skeletonized with Thunderbeat 28.3 min SD ± 9.11, P < 0.001]. No grafts discarded due to faulty harvesting and there was no graft failure within hospital stay.

CONCLUSIONS

We found no difference between the harvesting methods except for a significantly faster harvesting time with the pedicled technique. However, non-touch skeletonized LIMA harvesting with Thunderbeat seems to be an effective alternative to traditional surgical skeletonized LIMA. The future will reveal whether patency is harvesting dependent.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05562908.

European Association of Cardio-Thoracic Surgery (EACTS) expert consensus statement on perioperative myocardial infarction after cardiac surgery

Cardiac surgery may lead to myocardial damage and release of cardiac biomarkers through various mechanisms such as cardiac manipulation, systemic inflammation, myocardial hypoxia, cardioplegic arrest and ischaemia caused by coronary or graft occlusion. Defining perioperative myocardial infarction (PMI) after cardiac surgery presents challenges, and the association between the current PMI definitions and postoperative outcomes remains uncertain. To address these challenges, the European Association of Cardio-Thoracic Surgery (EACTS) facilitated collaboration among a multidisciplinary group to evaluate the existing evidence on the mechanisms, diagnosis and prognostic implications of PMI after cardiac surgery. The review found that the postoperative troponin value thresholds associated with an increased risk of mortality are markedly higher than those proposed by all the current definitions of PMI. Additionally, it was found that large postoperative increases in cardiac biomarkers are prognostically relevant even in absence of additional supportive signs of ischaemia. A new algorithm for PMI detection after cardiac surgery was also proposed, and a consensus was reached within the group that establishing a prognostically relevant definition of PMI is critically needed in the cardiovascular field and that PMI should be included in the primary composite outcome of coronary intervention trials.

Chinese expert consensus on the diagnosis and treatment of coronary microvascular diseases (2023 Edition)

Since the four working groups of the Chinese Society of Cardiology issued first expert consensus on coronary microvascular diseases (CMVD) in 2017, international consensus documents on CMVD have increased rapidly. Although some of these documents made preliminary recommendations for the diagnosis and treatment of CMVD, they did not provide classification of recommendations and levels of evidence. In order to summarize recent progress in the field of CMVD, standardize the methods and procedures of diagnosis and treatment, and identify the scientific questions for future research, the four working groups of the Chinese Society of Cardiology updated the 2017 version of the Chinese expert consensus on CMVD and adopted a series of measures to ensure the quality of this document. The current consensus has raised a new classification of CMVD, summarized new epidemiological findings for different types of CMVD, analyzed key pathological and molecular mechanisms, evaluated classical and novel diagnostic technologies, recommended diagnostic pathways and criteria, and therapeutic strategies and medications, for patients with CMVD. In view of the current progress and knowledge gaps of CMVD, future directions were proposed. It is hoped that this expert consensus will further expedite the research progress of CMVD in both basic and clinical scenarios.

Timing and threshold of high sensitive troponin T measurement for the prediction of mortality after cardiac surgery: a retrospective cohort analysis

BACKGROUND

High sensitive cardiac troponin T (hsTnT) is a widely used biomarker of myocardial injury. Along with other high sensitive troponins, HsTnT can predict mortality in both cardiac and non-cardiac surgery. The aim of this study was to determine the association between hsTnT serum elevations in the immediate postoperative period until 120 h after cardiac surgery and the occurrence of in-hospital mortality compared to the Simplified Acute Physiology Score 3 (SAPS3). Additionally, we identified an ideal hsTnT serum threshold to predict in-hospital mortality.

METHODS

We performed a retrospective single-institutional cohort analysis of 2179 patients undergoing cardiac surgery with cardiopulmonary bypass from 2013 to 2021. Logistic regression analysis was used to investigate an association of hsTnT at various time points and in-hospital mortality. The model was adjusted for relevant covariates including SAPS3, lactate and administered norepinephrine dosage. ROC analysis was performed to estimate the accuracy to predict mortality by serum hsTnT concentrations. This prediction was compared to the SAPS3 score. An ideal cutoff of hsTnT concentration was calculated by means of Youden index.

RESULTS

In total 7576 troponins were measured at the predefined timepoints. 100 (4.59%) patients died during the hospital stay. The fourth hsTnT on d3 (at 96-120 h postoperatively) showed the highest association with in-hospital death (OR 1.56; 95% CI (1.39-1.76); p < 0.001). This finding persisted after multivariable adjustment (aOR 1.34; 95% CI (1.18-1.53); p < 0.001). In contrast, the third hsTnT on d2 (at 48-72 h postoperatively) showed the best discrimination for in-hospital mortality (AUC 82.75%; 95% CI (0.77-0.89). The prediction by the third hsTnT was comparable to the in-hospital mortality prediction by SAPS3 (AUC 79.36%; 95% CI (0.73-0.85); p = 0.056). The optimal cutoff for the third hsTnT was calculated to be 1264 ng/L (Sensitivity 0.62; Specificity 0.88).

CONCLUSION

Elevated hsTnT after cardiac surgery was associated with an increased risk of in-hospital mortality. HsTnT measured on postoperative day 2 and 3 were most accurate to predict in-hospital mortality. The prediction of in-hospital mortality using hsTNT is comparable to mortality prediction using the SAPS3 score. HsTnT serum levels currently recommended to establish clinically important periprocedural myocardial injury are lower than thresholds identified in this study.

Defining Peri-Operative Myocardial Injury during Cardiac Surgery Using High-Sensitivity Troponin T

OBJECTIVE

Cut-offs for high-sensitivity troponin (hs-Tn) elevations to define prognostically significant peri-operative myocardial injury (PMI) in cardiac surgery is not well-established. We evaluated the associations between peri-operative high-sensitivity troponin T (hs-TnT) elevations and 1-year all-cause mortality in patients undergoing cardiac surgery.

METHODS

The prognostic significance of baseline hs-TnT and various thresholds for post-operative hs-TnT elevation at different time-points on 1-year all-cause mortality following cardiac surgery were assessed after adjusting for baseline hs-TnT and EuroSCORE in a post-hoc analysis of the ERICCA trial.

RESULTS

1206 patients met the inclusion criteria. Baseline elevation in hs-TnT >x1 99th percentile upper reference limit (URL) was significantly associated with 1-year all-cause mortality (adjusted hazard ratio 1.90, 95% confidence interval 1.15-3.13). In the subgroup with normal baseline hs-TnT (n = 517), elevation in hs-TnT at all post-operative time points was associated with higher 1-year mortality, reaching statistical significance for elevations above: ≥100 × URL at 6 h; ≥50 × URL at 12 and 24 h; ≥35 × URL at 48 h; and ≥30 × URL at 72 h post-surgery. Elevation in hs-TnT at 24 h ≥ 50 × URL had the optimal sensitivity and specificity (73% and 75% respectively). When the whole cohort of patients was analysed, including those with abnormal baseline hs-TnT (up to 10 × URL), the same threshold had optimal sensitivity and specificity (66% and 70%).

CONCLUSIONS

Both baseline and post-operative hs-TnT elevations are independently associated with 1-year all-cause mortality in patients undergoing cardiac surgery. The optimal threshold to define a prognostically significant PMI in our study was ≥50 × URL elevation in hs-TnT at 24 h.

Prognostic value of high-sensitivity cardiac troponin I early after coronary artery bypass graft surgery

BACKGROUND

The diagnosis of periprocedural myocardial infarction (PMI) after coronary artery bypass graft (CABG) is based on biochemical markers along with clinical and instrumental findings. However, there is not a clear cutoff value of high-sensitivity cardiac troponin (hs-cTn) to identify PMI. We hypothesized that isolated hs-cTn concentrations in the first 24 h following CABG could predict cardiac adverse events (in-hospital death and PMI) and/or left ventricular ejection fraction (LVEF) decrease.

METHODS

We retrospectively enrolled all consecutive adult patients undergoing CABG, alone or in association with other cardiac surgery procedures, over 1 year. Hs-cTn I concentrations (Access, Beckman Coulter) were serially measured in the post-operative period and analyzed according to post-operative outcomes.

RESULTS

300 patients were enrolled; 71.3% underwent CABG alone, 33.7% for acute coronary syndrome. Most patients showed hs-cTn I values superior to the limit required by the latest guidelines for the diagnosis of PMI. Five patients (1.7%) died, 8% developed a PMI, 10.6% showed a LVEF decrease ≥ 10%. Hs-cTn I concentrations did not significantly differ with respect to death and/or PMI whereas they were associated with LVEF decrease ≥ 10% (p value < 0.005 at any time interval), in particular hs-cTn I values at 9-12 h post-operatively. A hs-cTn I cutoff of 5556 ng/L, a value 281 (for males) and 479 (for females) times higher than the URL, at 9-12 h post-operatively was identified, representing the best balance between sensitivity (55%) and specificity (79%) in predicting LVEF decrease ≥ 10%.

CONCLUSIONS

Hs-cTn I at 9-12 h post-CABG may be useful to early identify patients at risk for LVEF decrease and to guide early investigation and management of possible post-operative complications.

High-sensitivity cardiac troponin I after coronary artery bypass grafting for post-operative decision-making

AIMS

Current troponin cut-offs suggested for the post-operative workup of patients following coronary artery bypass graft (CABG) surgery are based on studies using non-high-sensitive troponin assays or are arbitrarily chosen. We aimed to identify an optimal cut-off and timing for a proprietary high-sensitivity cardiac troponin I (hs-cTnI) assay to facilitate post-operative clinical decision-making.

METHODS AND RESULTS

We performed a retrospective analysis of all patients undergoing elective isolated CABG at our centre between January 2013 and May 2019. Of 4684 consecutive patients, 161 patients (3.48%) underwent invasive coronary angiography after surgery, of whom 86 patients (53.4%) underwent repeat revascularization. We found an optimal cut-off value for peak hs-cTnI of >13 000 ng/L [>500× the upper reference limit (URL)] to be significantly associated with repeat revascularization within 48 h after surgery, which was internally validated through random repeated sampling with 1000 iterations. The same cut-off also predicted 30-day major adverse cardiovascular events and all-cause mortality after a median follow-up of 3.1 years, which was validated in an external cohort. A decision tree analysis of serial hs-cTnI measurements showed no added benefit of hs-cTnI measurements in patients with electrocardiographic or echocardiographic abnormalities or haemodynamic instability. Likewise, early post-operative hs-cTnI elevations had a low yield for clinical decision-making and only later elevations (at 12-16 h post-operatively) using a threshold of 8000 ng/L (307× URL) were significantly associated with repeat revascularization with an area under the curve of 0.92 (95% confidence interval 0.88-0.95).

CONCLUSION

Our data suggest that for hs-cTnI, higher cut-offs than currently recommended should be used in the post-operative management of patients following CABG.

Procedure-Specific Relationships Between Postoperative Troponin T and a Composite of Mortality and Low Cardiac Output Syndrome: A Retrospective Cohort Analysis

BACKGROUND

Myocardial injury after coronary artery bypass grafting (CABG) is defined as troponin concentrations >10 times 99th percentile upper reference limit (URL) according to the Fourth Universal Definition. However, troponin concentrations after non-CABG cardiac surgery which indicate greater-than-expected myocardial injury and increased risk for complications remain unclear. Our goal was to assess procedure-specific relationships between troponin T and a composite outcome of low cardiac output syndrome and in-hospital mortality in cardiac surgical patients.

METHODS

Patients having cardiac surgery between January 2010 and December 2017 were categorized into 4 groups by procedure: (1) CABG; (2) mitral valve repair; (3) aortic valve repair/replacement (AVR); (4) mitral valve replacement (MVR) or CABG + valve surgeries. Exclusion criteria were elevated preoperative troponin T, preoperative kidney failure, circulatory arrest, or preoperative/planned mechanical circulatory support. Logistic regression was used to assess the association between troponin T and composite outcome, both overall and by procedure, including assessment of the interaction between procedure and troponin T on outcome.

RESULTS

Among 10,253 patients, 37 (0.4%) died and 393 (3.8%) developed the primary outcome. Troponin T concentrations differed by procedure (P < .001). Compared to CABG, AVR had 0.53 (99.2% confidence interval [CI], 0.50-0.56; unadjusted P < .001) times lower troponin T concentrations, while MVR/CABG + valve were 1.54 (99.2% CI, 1.45-1.62, unadjusted P < .001) times higher. There were linear relationships between log2 troponin T concentration and log odds mortality/low cardiac output syndrome. The (unadjusted) relationships were parallel for various types of surgery (interaction P = .59), but at different levels of the outcome.

CONCLUSIONS

The relative increase in odds for mortality/low cardiac output syndrome per a similar increase in troponin T concentrations did not differ among cardiac surgical procedures, but the absolute troponin T concentrations did. Troponin concentrations should thus be interpreted in context of surgical procedure.

Pathophysiology of Coronary Microvascular Dysfunction

Ischemic heart disease (IHD) is commonly recognized as the consequence of coronary atherosclerosis and obstructive coronary artery disease (CAD). However, a significant number of patients may present angina or myocardial infarction even in the absence of any significant coronary artery stenosis and impairment of the coronary microcirculation has been increasingly implicated as a relevant cause of IHD. The term "coronary microvascular dysfunction" (CMD) encompasses several pathogenic mechanisms resulting in functional and/or structural changes in the coronary microcirculation and determining angina and myocardial ischemia in patients with angina without obstructive CAD ("primary" microvascular angina), as well as in several other conditions, including obstructive CAD, cardiomyopathies, Takotsubo syndrome and heart failure, especially the phenotype with preserved ejection fraction. The pathogenesis of CMD is complex and involves the combination of functional and structural alterations leading to impaired coronary blood flow and resulting in myocardial ischemia. In the absence of therapies specifically targeting CMD, attention has been focused on the role of modifiable risk factors. Here, we provide updated evidence regarding the pathophysiological mechanisms underlying CMD, with a particular focus on the role of cardiovascular risk factors and comorbidities. Moreover, we discuss the specific pathogenic mechanisms of CMD across the different cardiovascular diseases, aiming to pave the way for further research and the development of novel strategies for a precision medicine approach.

Troponin T Elevation After Percutaneous Left Atrial Appendage Occlusion

Background: Cardiac troponin T (cTNT) has been widely used in detecting cardiac damage. Elevated cTNT level has been reported to be associated with increased mortality in multiple cardiac conditions. It is not uncommon to observe an increased level of cTNT in patients after left atrial appendage occlusion (LAAO). The objective of the study is to study the incidence, significance, and factors associated with cTNT elevation after LAAO.

Methods: We prospectively included patients who underwent LAAO from January 2019 to July 2020 in Fudan Zhongshan Hospital. Patients were divided into those with elevated cTNT after procedure and those with normal postprocedure cTNT. All individuals were followed up for 1 year. The primary outcome is major adverse cardiovascular events, which include myocardial infarction, heart failure, cardiac death, and stroke. The second outcome is periprocedure complication, including chest pain, tachycardia, cardiac tamponade, change of electrocardiograph, and atrial thrombus.

Results: A total of 190 patients were enrolled. Of the patients, 85.3% had elevated cTNT after LAAO, while 14.7% of them did not. Exposure time, dosage of contrast, types of devices, shapes, and sizes of LAA could contribute to elevated postprocedure cTNT. We found that patients with a Watchman device were more likely to have elevated postprocedure cTNT than those with a Lambre device (89.2 vs. 76.7%, p = 0.029). LAAO shapes were associated with cTNT levels in patients with a Watchman device, while the diameter of the outer disc and LAA depth mattered for the Lambre device. There was no significant difference in the primary and second outcome between the two groups (p-value: 0.619, 0.674).

Conclusion: LAAO was found to be commonly accompanied with cTNT elevation, which might not to be related to the complications and adverse cardiac outcomes within 1 year of follow-up. Moreover, eGFR at baseline, exposure time, dosage of contrast, types of LAAO device, and LAA morphology could contribute to cTNT elevation.

Coronary Microvascular Dysfunction Across the Spectrum of Cardiovascular Diseases: JACC State-of-the-Art Review

Coronary microvascular dysfunction (CMD) encompasses several pathogenetic mechanisms involving coronary microcirculation and plays a major role in determining myocardial ischemia in patients with angina without obstructive coronary artery disease, as well as in several other conditions, including obstructive coronary artery disease, nonischemic cardiomyopathies, takotsubo syndrome, and heart failure, especially the phenotype associated with preserved ejection fraction. Unfortunately, despite the identified pathophysiological and prognostic role of CMD in several conditions, to date, there is no specific treatment for CMD. Due to the emerging role of CMD as common denominator in different clinical phenotypes, additional research in this area is warranted to provide personalized treatments in this "garden variety" of patients. The purpose of this review is to describe the pathophysiological mechanisms of CMD and its mechanistic and prognostic role across different cardiovascular diseases. We will also discuss diagnostic modalities and the potential therapeutic strategies resulting from recent clinical studies.

Del Nido cardioplegia in adult cardiac surgery: analysis of myocardial protection and post-operative high-sensitivity Troponin T

BACKGROUND

del Nido cardioplegia has been adopted for use in adult cardiac surgery, despite a lack of robust randomised evidence supporting equivalence or superiority to conventional hyperkalaemic blood cardioplegia. We investigated the clinical surrogates of myocardial protection, and performed an extensive analysis of post-operative high-sensitivity Troponin T (hs-TnT) values in a general adult cardiac surgery population receiving del Nido, in comparison to a historical hyperkalaemic blood cohort.

METHOD

171 consecutive patients of a single surgeon from between November 2018 and June 2020 received del Nido, and were compared to a historical cohort of 326 patients between January 2016 and November 2018 who received hyperkalaemic blood cardioplegia. Clinical markers of myocardial protection were compared, as were hs-TnT values at 6, 12, 24, and 72-h post-operatively. Equivalence between groups was determined using the two one-sided tests procedure.

RESULTS

There was no difference between the groups in the incidence of post-operative low cardiac output state, inotropic support, or myocardial infarction. Del Nido patients had less defibrillation requirement, and more spontaneous resumption of normal sinus rhythm. High-sensitivity Troponin T values were similar at all time-points including in a coronary artery bypass graft subgroup, and in those patients with elevated pre-operative hs-TnT.

CONCLUSION

In a broad cohort of adult cardiac surgery patients, including those undergoing coronary artery bypass surgery and those with recent myocardial infarction, del Nido provides equivalent myocardial protection and clinical outcomes when compared to hyperkalemic blood cardioplegia. Post-operative high-sensitivity Troponin T values were also equivalent between the groups.

Release Profile of Cardiac Troponin T and Risk Factors of Postoperative Myocardial Injury in Patients Undergoing CABG

Background

Cardiac troponin T (cTnT) is currently one of the important indicators for clinical diagnosis of myocardial injury, which is inevitable in cardiac surgery, especially coronary artery bypass grafting (CABG). Describing the release profile of cTnT and finding out the risk factors of postoperative myocardial injury (PMI) are of great significance. The purposes of this study are to explore the release profile of cTnT in patients undergoing CABG and to search for independent risk factors of PMI.

Methods

In this retrospective study, clinical data of CABG patients were collected. The cTnT was measured at 24 hours before and 6, 12, 24, 48, 72, 96 and 120 hours after operation separately. The release profiles and peak time of cTnT in total cohort and sub-cohorts were observed. Independent risk factors of PMI were explored via univariate and multivariate logistic regression analyses.

Results

In total, 2084 patients were enrolled, including 998 patients in a cTnT group and 1086 patients in a high-sensitive cTnT (hs-cTnT) group. PMI was recognized in 797 patients. In both groups, cTnT showed a trend of rising first and then falling within 120 hours after operation. The peak cTnT appeared within 12–24 hours after operation, while the peak hs-cTnT occurred mostly within 24–48 hours after operation. Univariate logistic analysis showed that body mass index (BMI), New York Heart Association (NYHA) classification, coronary artery disease (CAD) classification, cerebrovascular disease, left ventricular ejection fraction, number of diseased vessels, valvular disease, intra-aortic balloon pump (IABP) implantation, chronic obstructive pulmonary disease, pulmonary hypertension, previous percutaneous coronary intervention (PCI), BMI, bypass graft number, cardiopulmonary bypass, and preoperative cTnT were related risk factors. Multivariate logistic regression analysis showed that NYHA classification, CAD classification, valvular disease, IABP implantation, pulmonary hypertension, previous PCI, bypass graft number, cardiopulmonary bypass, and preoperative cTnT were independent risk factors of PMI.

Conclusion

NYHA classification, CAD classification, valvular disease, IABP implantation, pulmonary hypertension, previous PCI, bypass graft number, cardiopulmonary bypass, and preoperative cTnT are independent risk factors of PMI in patients undergoing CABG.

Association of early elevated cardiac troponin I concentration and longitudinal change after off-pump coronary artery bypass grafting and adverse events: a prospective cohort study

Background

The elevation of troponin after coronary artery bypass grafting (CABG) is common This study aimed to investigate the association between very early cardiac troponin I (cTnI) concentration and its longitudinal change within 24 hours after CABG and 30-day adverse events.

Methods

This study prospectively enrolled 633 patients who underwent isolated off-pump CABG from January 2019 to May 2019. Serum cTnI levels were measured in all patients at two examinations within 24 hours postoperatively (1 hour and 12–18 hours), and a proportional hazards model was used to determine the association between cTnI levels and their change with adverse events, which were defined as a composite of 30-day mortality, stroke, heart failure, myocardial infarction (MI), and ventricular fibrillation.

Results

cTnI levels of the two examinations and absolute change of cTnI levels were significantly higher in the event group than in the non-event group (P<0.01, both). Earlier and later cTnI concentrations were associated with 30-day complications [adjusted hazard ration (HR) 1.598, 95% confidence interval (CI), 1.158–2.204 and HR 1.499, 95% CI, 1.228–1.831, respectively]. With regard to longitudinal change in cTnI levels, participants with persistently high levels of cTnI and those with progression from a low level to high level concentration experienced a significantly increased risk of adverse events than did participants who had a trend of persistently low cTnI levels (HR 3.105, 95% CI, 1.748–5.517 versus HR 2.944, 95% CI, 1.488–5.824).

Conclusions

Longitudinal change in cTnI levels within 24 hours and early cTnI concentrations, even less than 1 hour after CABG, are associated with adverse events. These data will be useful in identifying patients at an increased risk of complications.

The clinically effective use of cardiac markers by restructuring laboratory profiles at Cardiology wards

Background

Laboratory overutilization is associated with diagnostic error and potential patient risk. We applied a demand management strategy in collaboration with the local Department of Cardiology to reduce the cardiac markers high-sensitive troponin T (hsTropT) and N-terminal pro brain natriuretic peptide (NTproBNP) in laboratory ordering profiles (LOPs). The present study aimed to retrospectively evaluate the implemented strategies.

Methods

Strategies included educational measures and evidence-guided, active test de-selection from all cardiology ward LOPs, and/or permanent removal from LOPs. Tests remained available at all times. We evaluated overutilization by reductions in monthly orders, and assessed differences in 30-day all-cause readmission rate and length of patients' hospital stay.

Results

Overall, we observed a mean reduction of 66.1% ± 7.6% (n = 277 ± 31) in hsTropT tests. Educational measures effectively reduced NTproBNP orders by 52.8% ± 17.7% (n = 60 ± 20). Permanent removal of tests from LOPs additionally decreased orders to a final extent of 75.8% ± 8.0% (n = 322 ± 31) in NTproBNP tests. The 30-day readmission rate and overall length of hospital stay did not increase.

Conclusions

Our results indicate that cardiac markers in routine care are subject to extensive overutilization when used within LOPs. Educational measures are an effective strategy to overcome the overutilization of cardiac markers but may be more effective when combined with the removal of cardiac markers from LOPs.

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.

Analysis of Myocardial Ischemia Parameters after Coronary Artery Bypass Grafting with Minimal Extracorporeal Circulation and a Novel Microplegia versus Off-Pump Coronary Artery Bypass Grafting

Background

To compare the performance of our institutionally refined microplegia protocol in conjunction with minimal extracorporeal circulation system (MiECC) with off-pump coronary artery bypass grafting (OPCAB).

Methods

We conducted a single center study including patients undergoing isolated CABG surgery performed either off-pump or on-pump using our refined microplegia protocol in conjunction with MiECC. We used propensity modelling to calculate the inverse probability of treatment weights (IPTW). Primary endpoints were peak values of high-sensitivity cardiac troponin T (hs-cTnT) during hospitalization, and respective first values on the first postoperative day. Endpoint analysis was adjusted for intraoperative variables.

Results

After IPTW, we could include 278 patients into our analyses, 153 of which had received OPCAB and 125 of which had received microplegia. Standardized differences indicated that treatment groups were comparable after IPTW. The multivariable quantile regression yielded a nonsignificant median increase of first hs-cTnT by 39 ng/L (95% CI -8 to 87 ng/L, p = 0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84, p = 0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84, p = 0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84, p = 0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84.

Conclusion

The use of our institutionally refined microplegia in conjunction with MiECC was associated with similar results with regard to ischemic injury, expressed in hs-cTnT compared to OPCAB. MACCE was seen equally frequent. ICU discharge was earlier if microplegia was used.

Single-center experience with the combination of Cardioplexol™ cardioplegia and MiECC for isolated coronary artery bypass graft procedures

Background

Cardioplexol™ with its low volume (100 mL) was originally conceived as cardioplegic solution for MiECC procedures. Introduced in its current form in 2008 in our clinic, it has immediately demonstrated attractive advantages including the easy and rapid administration by the surgeon him/herself, the almost immediate cardiac arrest and a prolonged delay before a second dose is necessary. We report here the results of our initial experience with this simple solution.

Methods

Single centre, retrospective observational analysis of prospectively collected data of isolated coronary artery bypass graft (CABG) procedures performed with a MiECC.

Results

Of 7,447 adult cardiac surgical operations performed during a 76 months period, 2,416 were isolated CABG-MiECC procedures. Patients were 81.3% males, 66.2±9.7 years old and had a median logistic EuroSCORE of 3.2. In average 3.2±0.8 vessels were bypassed. Median cross-clamp time was 45 minutes and more than 75% of the patients received only one 100 mL dose of Cardioplexol™. At reperfusion more than 90% of the hearts spontaneously recovered a rhythmic activity. Maximal value of troponin T during the first hours following myocardial reperfusion was 0.9±4.5 ng/mL (median =0.4 ng/mL). Mortality at 30 days was 0.9%.

Conclusions

Cardioplexol™ seems very promising. It appears especially efficient and safe when used for CABG procedures performed with a MiECC.

Urinary Titin Is Increased in Patients After Cardiac Surgery

Background: Few non-invasive biomarkers have been used to detect myocardial injury in patients with heart diseases. Recently, the N-terminal fragment (N-titin) of titin, a giant sarcomeric protein, which is involved in muscular passive tension and viscoelasticity, has been reported to detect muscle damage in patients with cardiomyopathy as well as in patients with skeletal muscle dystrophy and in healthy volunteers with endurance exercise. In the present study, we evaluated whether urinary N-titin is changed during a perioperative period and whether its increase reflects myocardial damage.

Materials and Methods: In 18 patients who underwent cardiac surgery, blood and urine samples were obtained before and after surgery. We measured the urinary levels of N-titin with a highly sensitive ELISA system.

Results: Urinary N-titin to creatinine (N-titin/Cr) was significantly increased in all patients postoperatively (43.3 ± 39.5 pmol/mg/dL on the day of operation) and remained significantly high for at least 4 days postoperatively. Urinary N-titin/Cr was positively correlated with serum cardiac troponin T (r = 0.36, p = 0.0006, n = 90) but not creatine kinase-MB (CK-MB). We also found that urinary N-titin/Cr in patients after a coronary artery bypass grafting operation was higher by day 2 postoperatively than in patients following open cardiac surgeries.

Conclusion: The cleaved N-titin was significantly increased in urine after cardiac surgery. Urinary N-titin may be useful for detecting the risk of latent postoperative cardiac damage.

Association between Contrast Media Volume and 1-Year Clinical Outcomes in Patients Undergoing Coronary Angiography

Background:

The excess volume of contrast media (CM) is a marker of a more severe coronary culprit lesion and longer intervention duration in patients undergoing cardiac procedures. However, it is unclear whether the contrast volume is directly correlated with worse clinical outcomes. The aim of this study was to investigate the association between contrast dose and the incidence of 1-year major adverse cardiac and cerebrovascular events (MACCE) and all-cause bleeding events in patients undergoing cardiac catheterization and coronary angiography (CAG).

Methods:

We prospectively enrolled 10,961 consecutive patients diagnosed with coronary heart disease expecting CAG from 2012 to 2013. The study population was pursued with a follow-up duration of 1 year. The predictive value of contrast volume, divided into quartiles, for the risk of MACCE and all-cause bleeding events was assessed using logistic regression analysis.

Results:

The cumulative incidence of 1-year MACCE was 8.65%, which was directly associated with increasing contrast volume. In particular, MACCE was observed in 7.16%, 7.89%, 9.31%, and 11.73% of cases in the contrast volume quartile Q1 (≤100 ml), Q2 (101–140 ml), Q3 (141–200 ml), and Q4 (>200 ml), respectively (P < 0.001). Moreover, the incidence of 1-year all-cause bleeding events was noted in 4.70%, 5.93%, 7.28%, and 8.21% of patients in Q1, Q2, Q3, and Q4, respectively (P < 0.001). The survival analysis showed that the 1-year MACCE rate was higher in patients using greater CM volume during the CAG. CM volume used >140 ml was associated with the occurrence of 1-year MACCE, and the incidence was dramatically elevated in patients exceeding a contrast volume of 200 ml (P = 0.007).

Conclusion:

Our data suggested that higher contrast volume was significantly correlated with an increased risk of MACCE and all-cause bleeding events in patients undergoing cardiac catheterization.

Trial Registration:

ClinicalTrials.gov, NCT01735305; https://clinicaltrials.gov/ct2/show/NCT01735305?id=NCT017353057rank=1.