Determinants and Prognosis of Myocardial Damage After Coronary Artery Bypass Grafting

doi:10.1016/j.athoracsur.2004.07.060

The Annals of Thoracic Surgery

Volume 79, Issue 3, March 2005, Pages 837-845

https://doi.org/10.1016/j.athoracsur.2004.07.060 Get rights and content

Background

Myocardial infarction remains a devastating complication after coronary revascularization. Although electrocardiography (ECG) and echocardiography suggest transmural infarction, myocardial damage and the quality of myocardial protection are not recognized unless troponin I (TnI) is assessed. Determinants and prognosis of TnI elevation after coronary artery bypass grafting (CABG) were evaluated.

Methods

Data of 776 consecutive patients undergoing CABG between January 2002 and January 2004 were prospectively exposed to univariate and multivariate analysis. We evaluated the prognosis of patients with all the ECG, echocardiographic, and biochemical criteria for acute myocardial infarction and that of patients with only TnI elevation. Twelve-month follow-up survival and freedom from cardiac events (FCE) were accomplished.

Results

Troponin I greater than 3.1 μg/L at 12 hours was detected in 6.9% of the population, and correlated with lower in-hospital (p < 0.001) and follow-up survival (p = 0.00001), and lower FCE (p = 0.0009). Twenty-one (38.8%) of these fulfilled ECG-echocardiographic criteria (p = 0.05), demonstrating higher TnI values at 12 (p = 0.001), 24 (p = 0.01), 48 (p = 0.01), and 72 (p = 0.04) hours, prolonged ventilation time (p = 0.001), higher in hospital mortality (p = 0.003), lower follow-up survival (p = 0.023), and lower FCE (p = 0.0084). A EuroSCORE greater than 6, ongoing unstable angina, aortic cross-clamp time greater than 90 minutes, cardiopulmonary bypass time greater than 180 minutes, incomplete revascularization, and intraoperative intraaortic balloon pump were independent predictors of myocardial damage (MD) at multivariate analysis. Combined antegrade and retrograde cardioplegia and postoperative enoximone infusion were associated with a lower TnI elevation.

Conclusions

Troponin I greater than 3.1 μg/L at 12 hours defines perioperative MD. Associated ECG-echocardiographic criteria indicate acute myocardial infarction and anticipate a worse outcome. Identification of predictors for MD is important to develop preventative strategies, as antegrade plus retrograde cardioplegia and enoximone infusion.

Section snippets

Material and Methods

A total of 776 consecutive adult patients undergoing primary isolated coronary artery bypass grafting between January 2002 and January 2004 were prospectively enrolled in the study. Fifty-eight perioperative risk factors analyzed by univariate and multivariate stepwise logistic regression are listed in the Appendix.

Of preoperative variables, number and type of diseased vessels were determined based on the angiography of the patient. The left anterior descending, left circumflex, right coronary

Results

The overall incidence of postoperative TnI elevation greater than 3.1 μ:g/L was 6.9% (54 of 776 patients). Only 21 (38.8%) of these fulfilled ECG or echocardiographic criteria for perioperative AMI (p = 0.05). Compared to patients with only TnI elevation, those with ECG and echocardiographic criteria demonstrated a higher value of TnI at 12, 24, 48, and 72 hours postsurgery (Fig 1), a more prolonged ventilation time (81 ± 34.5 hours vs 27.9 ± 25.1; p = 0.001), and a higher in-hospital mortality

Comment

Despite advances in surgical skill, intraoperative techniques and devices, and postoperative management, perioperative myocardial infarction is still a life-threatening complication after isolated myocardial revascularization, responsible for early and late cardiovascular events and mortality 1, 2. In the last few years, the introduction of new biochemical markers of myocardial damage, such as the isoforms T and I of troponin, with their higher sensitivity and specificity in diagnosing such

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It is also conceivable that the presence of an ICT reflects an underlying hypercoagulable state that may predispose to the formation of additional thrombi in the context of LVAD implantation.19 Prolonged CPB time has been previously associated with higher morbidity and mortality.20–22 In our analyses, we found that CPB time was significantly longer in patients with ICT.
Heart failure predisposes to intracardiac thrombus (ICT) formation. There are limited data on the prevalence and impact of preexisting ICT on postoperative outcomes in left ventricular assist device patients. We examined the risk for stroke and death in this patient population.
We retrospectively studied patients who were implanted with HeartMate (HM) II or HM3 between February 2009 and March 2019. Preoperative transthoracic echocardiograms, intraoperative transesophageal echocardiograms and operative reports were reviewed to identify ICT. There were 525 patients with a left ventricular assist device (median age 60.6 years, 81.8% male, 372 HMII and 151 HM3) included in this analysis. An ICT was identified in 44 patients (8.4%). During the follow-up, 43 patients experienced a stroke and 55 died. After multivariable adjustment, presence of ICT increased the risk for the composite of stroke or death at 6-month (hazard ratio [HR] 1.82, 95% confidence interval [CI] 1.00–3.33, P = .049). Patients with ICT were also at higher risk for stroke (HR 2.45, 95% CI 1.14–5.28, P = .021) and death (HR 2.36, 95% CI 1.17–4.79 P = .016) at 6 months of follow-up.
The presence of ICT is an independent predictor of stroke and death at 6 months after left ventricular assist device implantation. Additional studies are needed to help risk stratify and optimize the perioperative management of this patient population.
Diagnostic dilemma of perioperative myocardial infarction after coronary artery bypass grafting: A review
2020, International Journal of Surgery
Citation Excerpt :
As previously shown, Q waves are predictive for ischemic changes in particular if accompanied by enzyme elevation. Onorati et al., in their prospective study, showed that patients with TnI elevation and associated ECG or echocardiographic changes had a lower survival and lower freedom of cardiac events compared to TnI elevation only (38.5 ± 14.8% vs 72.7 ± 15.0%; p = 0.023) [57]. As there is no comprehensive single test available, this seems currently the most promising method to rule out ischemia mimicking signs.
Coronary artery bypass grafting (CABG) is one of the most commonly performed cardiac procedures in the United States (US) and Europe. In the US, perioperative morbidity and mortality related to CABG are below 5%. One of the most significant complications following CABG, however, is perioperative myocardial infarction (PMI). Cardiac biomarkers, intra- and post-operative echocardiography, and electrocardiography are routinely used to monitor for evidence of PMI. In this review, we seek to summarize how each of these modalities is used in the clinical setting to differentiate PMI from expected procedure-related changes, and how these findings impact patients’ outcomes. We conclude that while no perfect diagnostic test for the detection of clinically meaningful PMI exists, using a combination of existing modalities with knowledge of expected post-procedure changes allows for early and reliable detection. Future development is needed to create more sensitive and specific modalities for the detection of PMI in patients undergoing CABG.
Detecting patients with PMI post-CABG based on cardiac troponin-T profiles: A latent class mixed modeling approach
2020, Clinica Chimica Acta
Citation Excerpt :
Several studies have focused on the release profile (or kinetics) of cTn post-CABG, arguing that insight in the normal postoperative release profile can aid clinicians in recognizing patients with PMI and that timing of the peak is relevant when applying cut-off values [10–12]. Aside from the normal post-operative CABG cTn release profile, studies describe profiles for off-pump CABG (OPCAB) surgery [10,11,13] and surgeries complicated by PMI [10–12,14–17]. While these studies demonstrate the variability in cTn release profiles and their value in recognizing PMI, they a priori define subgroups based on clinical characteristics or outcomes and subsequently evaluate cTn profiles.
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.
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).
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.
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.
Effects of Cross-Clamping on Vascular Mechanics: Comparing Waveform Analysis With a Numerical Model
2019, Journal of Surgical Research
Immediate changes in vascular mechanics during aortic cross-clamping remain widely unknown. By using a numerical model of the arterial network, vascular compliance and resistance can be estimated and the time constant of pressure waves can be calculated and compared with results from the classic arterial waveform analysis.
Experimental data were registered from continuous invasive radial artery pressure measurements from 11 patients undergoing vascular surgery. A stable set of beats were chosen immediately before and after each clamping event. Through the arterial waveform analysis, the time constant was calculated for each individual beat and for a mean beat of each condition as to compare with numerical simulations. Overall proportional changes in resistance and compliance during clamping and unclamping were calculated using the numerical model.
Arterial waveform analysis of individual beats indicated a significant 10% median reduction in the time constant after clamping, and a significant 17% median increase in the time constant after unclamping. There was a positive correlation between waveform analysis and numerical values of the time constant, which was moderate (ρ = 0.51; P = 0.01486) during clamping and strong (ρ = 0.77; P ≤ 0.0001) during unclamping. After clamping, there was a significant 16% increase in the mean resistance and a significant 23% decrease in the mean compliance. After unclamping, there was a significant 19% decrease in the mean resistance and a significant 56% increase in the mean compliance.
There are significant hemodynamic changes in vascular compliance and resistance during aortic clamping and unclamping. Numerical computer models can add information on the mechanisms of injury due to aortic clamping.
Prognostic Impact of Prolonged Cross-Clamp Time in Coronary Artery Bypass Grafting
2018, Heart Lung and Circulation
The prognostic impact of cross-clamp time (XCT) in patients undergoing isolated coronary artery bypass grafting (CABG) has not been thoroughly investigated.
2957 patients who underwent on-pump isolated CABG from the prospective multicentre E-CABG study were the subjects of this analysis.
The mean XCT in this series was 58 ± 25 minutes Cross-clamp time was >60 minutes in 1134 patients (38.3%), >75 minutes in 619 patients (20.9%) and >90 minutes in 296 patients (10.0%). Multivariate analysis showed that XCT was an independent predictor of 30-day mortality (p < 0.0001, OR 1.027, 95%CI 1.015–1.039) along with age (p < 0.0001), female gender (p = 0.001), pulmonary disease (p = 0.001), poor mobility (p = 0.002), urgency status (p = 0.007), critical preoperative status (p = 0.002) and participating centres (p = 0.015). Adjusted risk of 30-day mortality was highest for XCT >75 minutes (2.9% vs. 1.7%, p = 0.002, OR 3.479, 95%CI 1.609–7.520). Analysis of 428 propensity score matched pairs showed that XCT >75 minutes was associated with significantly increased risk of early mortality, prolonged use of inotropes, postoperative use of intra-aortic balloon pump, use of extracorporeal membrane oxygenation, atrial fibrillation, prolonged stay in the intensive care unit and of composite major adverse events.
Isolated CABG is currently performed with prolonged XCT in a significant number of patients and this seems to be a determinant of poor early outcome.
Our modified technique of combined antegrade-vein graft cardioplegia infusion versus conventional antegrade method in coronary artery bypass grafting. A randomized clinical trial
2018, International Journal of Surgery
To determine the efficacy of antegrade cardioplegia supplemented with venous graft perfusion in patients scheduled for coronary artery bypass grafting (CABG).
223 consecutive patients scheduled for isolated CABG were randomized to receive either continuous crystalloid cardioplegia via vein grafts on completion of each distal anastomosis plus intermittent blood cardioplegia through aortic root (group 1, n = 110) or antegrade blood cardioplegia alone (group 2, n = 113). Two groups were similar in terms of preoperative patients' and procedural characteristics. The primary end-points were low output syndrome (LOS) variables.
The inotrope and intra-aortic balloon pump demand during weaning were significantly higher in the control group (31.8% vs. 20%, p = 0.043 and 7.9% vs. 1.8%, p = 0.034 respectively). Postoperative level of potassium and arterial base excess (BE), stood in the normal range in both groups, despite significant inter-group differences. Peak serum level of myocardial injury biomarkers (CK, CK-MB, and cTnI) at 12 h following operation, though markedly greater in the group 2, did not reach the cut-off point of myocardial necrosis. Postoperative arrhythmia was more commonly encountered in the control group (p = 0.045).
The duration of ventilation and hospital stay were considerably longer in the group 2. In a subgroup with LVEF<30%, the length of ICU stay was more prolonged in the control group, as well (p = 0.0145). The significant differences among groups regarding LOS parameters were more remarkable in the two high-risk subgroups (LVEF<30%, left main coronary stenosis).
Given the better postoperative cardiac performance, we recommend this method to all CABG candidates, particularly in higher-risk patients.

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Original articleCardiovascularDeterminants and Prognosis of Myocardial Damage After Coronary Artery Bypass Grafting

Background

Methods

Results

Conclusions

Section snippets

Material and Methods

Results

Comment

Chest

Ann Thorac Surg

Ann Thorac Surg

Ann Thorac Surg

Ann Thorac Surg

Ann Thorac Surg

Ann Thorac Surg

Ann Thorac Surg

J Thorac Cardiovasc Surg

European system for cardiac operative risk evaluation (EuroSCORE)

Eur J Cardiothorac Surg

Off pump coronary artery bypass grafting in EuroSCORE high and low risk patients

Eur J Cardiothorac Surg

Original article
Cardiovascular
Determinants and Prognosis of Myocardial Damage After Coronary Artery Bypass Grafting