Association of Myocardial Enzyme Elevation and Survival Following Coronary Artery Bypass Graft Surgery. JAMA 305(6):585-91

Mount Sinai Cardiovascular Institute, New York, New York 10029, USA.
JAMA The Journal of the American Medical Association (Impact Factor: 35.29). 02/2011; 305(6):585-91. DOI: 10.1001/jama.2011.99
Source: PubMed


Several small studies have suggested that cardiac enzyme elevation in the 24 hours following coronary artery bypass graft (CABG) surgery is associated with worse prognosis, but a definitive study is not available. Also, the long-term prognostic impact of small increases of perioperative enzyme has not been reported.
To quantify the relationship between peak post-CABG elevation of biomarkers of myocardial damage and early, intermediate-, and long-term mortality, including determining whether there is a threshold below which elevations lack prognostic significance.
Studies (randomized clinical trials or registries) of patients undergoing CABG surgery in which postprocedural biomarker and mortality data were collected and included. A search of the PubMed database was performed in July 2008 using the search terms coronary artery bypass, troponin, CK-MB, and mortality.
Studies evaluating mortality and creatine kinase (CK-MB), troponin, or both were included. One study investigator declined to participate and 3 had insufficient data.
Two independent reviewers determined study eligibility. The principal investigator from each eligible study was contacted to request his/her participation. Once institutional review board approval for the use of these data for this purpose was obtained, we requested patient-level data from each source. Data were examined to ensure that cardiac markers had been measured within 24 hours after CABG surgery, key baseline covariates, and mortality were available.
A total of 18,908 patients from 7 studies were included. Follow-up varied from 3 months to 5 years. Mortality was found to be a monotonically increasing function of the CK-MB ratio. The 30-day mortality rates by categories of CK-MB ratio were 0.63% (95% confidence interval [CI], 0.36%-1.02%) for 0 to <1, 0.86% (95% CI, 0.49%-1.40%) for 1 to <2, 0.95% (95% CI, 0.72%-1.22%) for 2 to <5, 2.09% (95% CI, 1.69%-2.57%) for 5 to <10, 2.78% (95% CI, 2.12%-3.58%) for 10 to <20, and 7.06% (95% CI, 5.46%-8.96%) for 20 to ≥40. Of the variables considered, the CK-MB ratio was the strongest independent predictor of death to 30 days and remained significant even after adjusting for a wide range of baseline risk factors (χ(2) = 143, P < .001; hazard ratio [HR] for each 5 point-increment above the upper limits of normal [ULN] = 1.12; 95% CI, 1.10-1.14). This result was strongest at 30 days, but the adjusted association persisted from 30 days to 1 year (χ(2) = 24; P < .001; HR for each 5-point increment above ULN = 1.17; 95% CI, 1.10-1.24) and a trend was present from 1 year to 5 years (χ(2) = 2.8; P = .10; HR for each 5-point increment above ULN = 1.05; 95% CI, 0.99-1.11). Similar analyses using troponin as the marker of necrosis led to the same conclusions (χ(2) = 142 for 0-30 days and χ(2) = 40 for 30 days to 6 months, both P < .001; HR for each 50 points above the ULN = 1.28; 95% CI, 1.23-1.33 and 1.15; 95% CI, 1.10-1.21, respectively).
Among patients who had undergone CABG surgery, elevation of CK-MB or troponin levels within the first 24 hours was independently associated with increased intermediate- and long-term risk of mortality.

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Available from: Sorin J Brener, Dec 27, 2013
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    • "The term " perioperative myocardial injury " describes a condition that, although not fully achieving MI type 5, has health consequences even at this level of affection. A new retrospective study on 18,908 CABG patients has found that CK-MB/troponin elevations in the initial 24 hours were associated with increased mortality in the coming months to years [9]. Thus, it is obvious that the restriction of perioperative myocardial injury is important for the prognosis of the patient. "
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    ABSTRACT: Cardiac surgery patients are now more risky in terms of age, comorbidities, and the need for complex procedures. It brings about reperfusion injury, which leads to dysfunction and/or loss of part of the myocardium. These groups of patients have a higher incidence of postoperative complications and mortality. One way of augmenting intraoperative myocardial protection is the phenomenon of myocardial conditioning, elicited with brief nonlethal episodes of ischaemia-reperfusion. In addition, drugs are being tested that mimic ischaemic conditioning. Such cardioprotective techniques are mainly focused on reperfusion injury, a complex response of the organism to the restoration of coronary blood flow in ischaemic tissue, which can lead to cell death. Extensive research over the last three decades has revealed the basic mechanisms of reperfusion injury and myocardial conditioning, suggesting its therapeutic potential. But despite the enormous efforts that have been expended in preclinical studies, almost all cardioprotective therapies have failed in the third phase of clinical trials. One reason is that evolutionary young cellular mechanisms of protection against oxygen handling are not very robust. Ischaemic conditioning, which is among these, is also limited by this. At present, the prevailing belief is that such options of treatment exist, but their full employment will not occur until subquestions and methodological issues with the transfer into clinical practice have been resolved.
    Full-text · Article · Aug 2014 · BioMed Research International
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    • "Peri-operative cell death is substantiated by the release of these biomarkers into the plasma (Costa et al., 2001; Lehrke et al., 2004). Numerous studies have shown that these elevations in perioperative CK-MB or cTn (within 24–48 h) are correlated with both short-term and longterm risk of mortality (Klatte et al., 2001; Lehrke et al., 2004; Domanski et al., 2011). This increase in biomarkers after surgery has been ascribed in part to suboptimal intra-operative myocardial protection. "
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    ABSTRACT: Despite surgical proficiency and innovation driving low mortality rates in cardiac surgery, the disease severity, comorbidity rate, and operative procedural difficulty have increased. Today's cardiac surgery patient is older, has a "sicker" heart and often presents with multiple comorbidities; a scenario that was relatively rare 20 years ago. The global challenge has been to find new ways to make surgery safer for the patient and more predictable for the surgeon. A confounding factor that may influence clinical outcome is high K(+) cardioplegia. For over 40 years, potassium depolarization has been linked to transmembrane ionic imbalances, arrhythmias and conduction disturbances, vasoconstriction, coronary spasm, contractile stunning, and low output syndrome. Other than inducing rapid electrochemical arrest, high K(+) cardioplegia offers little or no inherent protection to adult or pediatric patients. This review provides a brief history of high K(+) cardioplegia, five areas of increasing concern with prolonged membrane K(+) depolarization, and the basic science and clinical data underpinning a new normokalemic, "polarizing" cardioplegia comprising adenosine and lidocaine (AL) with magnesium (Mg(2+)) (ALM™). We argue that improved cardioprotection, better outcomes, faster recoveries and lower healthcare costs are achievable and, despite the early predictions from the stent industry and cardiology, the "cath lab" may not be the place where the new wave of high-risk morbid patients are best served.
    Full-text · Article · Aug 2013 · Frontiers in Physiology
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    • "peak value reflects the extent of myocardial damage and postoperative elevation is a predictor of adverse outcome (myocardial infarction, shock and mortality) [13] [14]. Furthermore, increased preoperative cardiac troponin was found to be associated with morbidity and mortality [15]. "
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    ABSTRACT: OBJECTIVES Prediction of atrial fibrillation (AF) after coronary artery bypass grafting (CABG) may lead to preventive or early treatment and improved outcome. We investigated the association of serial perioperative cardiac troponin T (cTNT) measurements with postoperative AF in patients undergoing CABG.METHODS In a retrospective analysis of prospectively collected data, 3148 patients undergoing elective CABG were evaluated. cTNT values were routinely determined before the start of surgery (cTNT0), at arrival on the intensive care unit (cTNT1) and 8-12 h later (cTNT2). Measurement of cTNT was continued until the peak value was reached. The development of AF during hospital stay was scored. The association between cTNT (cTNT0, cTNT1, cTNT2 and cTNTmax in first 48 h) and AF was calculated in univariable and multivariable analysis.RESULTSAF occurred in 1080 (34%) patients. cTNT0, cTNT2 and cTNTmax were significantly and positively associated with postoperative AF (P < 0.001) in a univariable analysis, whereas a trend was seen for cTNT1 (P = 0.051). Advanced age, inotropic support and postoperative infection were independently associated with postoperative AF after logistic regression analysis, but cTNT was not. Categorizing patients by inotropic support into categories of inotropic support duration (none, <48 h, >48 h), the mean cTNT values were significantly higher among patients with AF in each category (all P < 0.001). Perioperative cTNT was significantly higher in patients with postoperative complications, longer hospital stay and reduced in-hospital survival.CONCLUSIONS Perioperative cTNT is univariably associated with postoperative AF after CABG, but not independently. Further, no clinically useful cut-off point for preventive or early treatment could be identified. Both perioperative cTNT and postoperative AF are associated with negative outcome and prolonged hospital stay.
    Full-text · Article · Jun 2013 · Interactive Cardiovascular and Thoracic Surgery
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