Sensitive Marker Of Myocardial Damage Research Articles

Non-invasive left ventricular myocardial work in patients with chronic aortic regurgitation and preserved left ventricular ejection fraction

Abstract Funding Acknowledgements Type of funding sources: None. Background Left ventricular global longitudinal strain (LV GLS) has been proposed as sensitive marker of myocardial damage in patients with chronic severe aortic regurgitation (AR) and preserved left ventricular ejection fraction (LVEF). However, LV GLS does not take into account the afterload. Non-invasive LV myocardial work is a novel parameter of LV myocardial performance, which integrates measurements of myocardial deformation and non-invasive blood pressure (afterload). Purpose The aims of this study were: 1) to assess non-invasive LV myocardial work in patients with chronic AR and preserved LVEF and its correlation with other echocardiographic parameters, 2) to evaluate changes of LV myocardial work after aortic valve replacement or repair (AVR) and 3) to assess the relationship between LV myocardial work and post-operative LV reverse remodeling. Methods This retrospective study included fifty patients (53 ± 16 years; 68% men) with moderate or severe chronic AR and preserved LVEF, who underwent AVR. Non-invasive LV myocardial work indices were measured at baseline and post-operatively (between 2 and 12 months after surgery) and compared with previously reported normal reference ranges. Results Based on normal reference values, patients with chronic AR and preserved LVEF had preserved or increased values of LV global work index (LV GWI) (84% and 16%, respectively) and LV global constructive work (LV GCW) (78% and 22%, respectively) (Figure 1). In addition, LV global work efficiency (LV GWE) was preserved in all patients, despite 16 (32%) subjects had impaired values of LV GLS (<16.7.% in men and <17.8% in women). LV GWI and GCW showed a positive correlation with markers of AR severity and parameters of LV systolic function. AVR results in a significant reduction of myocardial work indices (p < 0.0001), with the exception of LV global wasted work, that did not change (p = 0.29). According to normal reference ranges, 15 (30%) patients had impaired values of LV GWI and LV GCW post-operatively, while LV GLS was impaired in 37 (74%) patients. The post-operative impairment of LV GWI demonstrated a stronger association with reduced LV reverse remodeling, as compared to the impairment of LV GLS (Figure 2). Conclusions Compared to afterload-dependent echocardiographic parameters, non-invasive LV myocardial work indices allow a better understanding of myocardial performance and energetics in the setting of chronic AR with preserved LVEF and could improve risk stratification. Abstract Figure. Abstract Figure.

Noninvasive Left Ventricular Myocardial Work in Patients with Chronic Aortic Regurgitation and Preserved Left Ventricular Ejection Fraction

Left ventricular (LV) global longitudinal strain (GLS) has been proposed as a sensitive marker of myocardial damage in patients with chronic severe aortic regurgitation (AR) and preserved LV ejection fraction (LVEF). However, LV GLS does not take into account the afterload. Noninvasive LV myocardial work is a novel parameter of LV myocardial performance, which integrates measurements of myocardial deformation and noninvasive blood pressure (afterload). The aims of this study were (1) to assess noninvasive LV myocardial work in patients with chronic AR and preserved LVEF and its correlation with other echocardiographic parameters, (2) to evaluate changes of LV myocardial work after aortic valve replacement or repair (AVR), and (3) to assess the relationship between LV myocardial work and postoperative LV reverse remodeling. Fifty-seven patients (53±16years; 67% men) with moderate or severe chronic AR and preserved LVEF treated by AVR were included. Noninvasive LV myocardial work indices were measured at baseline and postoperatively (between 2 and 12months after surgery) and compared with previously reported normal reference ranges. Based on normal reference values, patients with chronic AR and preserved LVEF had preserved or increased values of LV global work index (GWI; 82% and 18%, respectively) and LV global constructive work (GCW; 74% and 25%, respectively) and preserved LV global work efficiency (GWE). Left ventricular GWI and GCW showed a positive correlation with markers of AR severity and parameters of LV systolic function. Left ventricular GWI, GCW, and GWE decreased after AVR (P<.001), without changes in LV global wasted work (P=.28). The postoperative impairment of LV GWI, observed in 28% of patients, was closely associated with reduced LV reverse remodeling. Noninvasive myocardial work may allow better understanding of myocardial function and energetics than afterload-dependent echocardiographic parameters in chronic AR with preserved LVEF.

DOES CARDIAC TROPONIN€“I IS RECOGNIZED AS AN EARLY POSTOPERATIVE MARKER FOR MYOCARDIAL DAMAGE IN CHILDREN?

Introduction:Cardiac troponin-I being a sensitive marker of myocardial damage needs to be analyzed in children undergoing cardiopulmonary by-pass surgery, as perioperative myocardial damage may be a significant factor of postoperative cardiac performance. The present study aims to test the prognostic value of Cardiac troponin-I concerning the early postoperative course after pediatric cardiac surgery. Methods:Cardiac troponin – I levels were measured and correlated with intra and postoperative parameters of thirty-three children undergoing open-heart surgery. The cutoff point for the definition of a high and a low-risk group of Cardiac troponin-I values was set at 25 ng/ml. Results:Overall, cTnI peak value was higher than 25 ng/ml in 21 patients among these,4 died, and two of them were reported with the value of &gt;100 ng/ml. 38.7% of the patients were complicated by different types of arrhythmias. Junctional ectopic tachycardia was the most common type of arrhythmia,while heart block complication was found only in one case, which was temporarily treated by pacing for less than 24 hours. The results showed significant correlation of troponin I values with dobutamine dose mg/kg (p-value=0.043), dobutamine duration (p-value=0.020), creatinine (p-value= 0.002), and internalcare unit stay (p-value= 0.003). Conclusion: The present study confirms that troponin I is specific and sensitive marker of myocardial injury after pediatric cardiac surgery.

Troponin T-release associates with cardiac radiation doses during adjuvant left-sided breast cancer radiotherapy.

BackgroundAdjuvant radiotherapy (RT) for left-sided breast cancer increases cardiac morbidity and mortality. For the heart, no safe radiation threshold has been established. Troponin T is a sensitive marker of myocardial damage. Our aim was to evaluate the effect of left-sided breast cancer RT on serum high sensitivity troponin T (hscTnT) levels and its association with cardiac radiation doses and echocardiographic parameters.MethodsA total of 58 patients with an early stage, left-sided breast cancer or ductal carcinoma in situ (DCIS) who received adjuvant breast RT without prior chemotherapy were included in this prospective, non-randomized study. Serum samples were taken before, during and after RT. An increase of hscTnT >30 % was predefined as significant. A comprehensive 2D echocardiograph and electrocardiogram (ECG) were performed before and after RT. Dose-volume histograms (DVHs) were generated for different cardiac structures.ResultsThe hscTnT increased during RT from baseline in 12/58 patients (21 %). Patients with increased hscTnT values (group A, N = 12) had significantly higher radiation doses for the whole heart (p = 0.02) and left ventricle (p = 0.03) than patients without hscTnT increase (group B, N = 46). For the left anterior descending artery (LAD), differences between groups A and B were found in volumes receiving 15 Gy (p = 0.03) and 20 Gy (p = 0.03) Furthermore, after RT, the interventricular septum thickened (p = 0.01), and the deceleration time was prolonged (p = 0.008) more in group A than in group B.ConclusionsThe increase in hscTnT level during adjuvant RT was positively associated with the cardiac radiation doses for the whole heart and LV in chemotherapy-naive breast cancer patients. Whether these acute subclinical changes increase the risk of excessive long-term cardiovascular morbidity or mortality, will be addressed in the follow-up of our patients.

Heart-type fatty acid-binding protein is a novel prognostic marker in patients with essential hypertension

Heart-type fatty acid-binding protein (H-FABP) is a small protein that is abundantly expressed in the cytosol of cardiomyocytes [1], and is known to be a sensitive marker of myocardial damage, such as acute myocardial infarction [2]. Recent studies, including our own ones, have reported that increased levels of myocardial damage markers, cardiac troponin T and H-FABP, can identify patients with chronic heart failure at an increased risk for future cardiac events [3–6]. Hypertension (HT) is an important precursor of heart failure, and it is the principal cause of cardiovascular and cerebrovascular diseases (CCVDs) [7].

Heart-type fatty acid-binding protein is a novel prognostic marker in patients with essential hypertension

Purpose: Heart-type fatty acid-binding protein (H-FABP), a sensitive marker of myocardial damage, is a useful diagnostic and prognositic marker in patients with cardiovascular disease, not only acute coronary syndrome but also chronic heart failure. We investigated whether H-FABP is a useful prognostic marker in patients with hypertension (HT), a major risk factor of acute coronary syndrome and heart failure. Methods: We measured serum levels of H-FABP in 192 patients with essential HT without prior cerebro-cardiovascular disease (CCVD) and renal failure (estimated glomerular filtration rate [eGFR] < 30ml/min/1.73m2), and compared the prognostic value of H-FABP with clinical parameters including coronary risk factors, neurohumoral factors (plasma renin activity, plasma aldosterone, norepinephrine and B-type natriuretic peptide [BNP] concentrations) and echocardiographic findings. Results: Over a mean follow-up period of 55 months, 37 patients developed CCVD (15 heart failure, 3 acute coronary syndrome, 4 aortic dissection, 11 cerebral infarction, 2 cerebral hemorrhage, 1 transient ischemic attack and 1 arteriosclerosis obliterans). Kaplan-Meier analysis revealed that the freedom from CCVD rate was significantly lower in patients with H-FABP > 3.6 ng/ml (median value) than in those with H-FABP ≤ 3.6ng/ml (hazard ratio p=0.001). On a Cox multivariate analysis including 6 variables (male gender, eGFR median value) that were significant predictors of CCVD by univariate analyses, H-FABP > 3.6 ng/ml (hazard ratio 2.37, p=0.03) and eGFR < 60ml/min/1.73m2 (hazard ratio 2.21, p=0.03) were independent predictors of future CCVD. Conclusion: H-FABP is a novel and useful marker for the prediction of future CCVD beyond conventional risk factors in patients with essential HT.

Elevated Troponin Level with Negative Outcome Was Found in Ischemic Stroke

Background. Troponin increment is a highly sensitive and specific marker of myocardial necrosis. The reason of high troponin levels in acute stroke is not clear. The aim of this study was to identify the relationships between cardiac troponin-I (cTnI) level and stroke. Methods. This study recruited 868 patients who were admitted to Istanbul Medeniyet University due to acute ischemic stroke, and the diagnosis was confirmed by diffusion magnetic resonance imaging. The patients with the causes increasing troponin level were excluded from the study. A total of 239 patients were finally included in the study. Clinics were evaluated by the modified Rankin Scale (mRS) and the National Institutes of Health Stroke Scale (NIHSS). Results. Serum level of troponin was higher in ischemic stroke patients with anterior circulation involvement in comparison to posterior involvement or hemorrhagic stroke (P < 0.05). Higher troponin levels related to increased stroke scale scores at discharge in ischemic stroke (P < 0.05). The level of cTnI was correlated with stroke scale scores at both admission and discharge in posterior stroke patients (P < 0.01). Conclusion. cTnI is a highly specific and sensitive marker of myocardial damage, and its elevation was associated with more severe neurological deficits in acute ischemic stroke.

Cardiac involvement in acute thrombotic thrombocytopenic purpura: association with troponin T and IgG antibodies to ADAMTS 13.

Evidence for cardiac involvement in thrombotic thrombocytopenic purpura (TTP) is uncommonly described. We retrospectively reviewed 41 patients assessing troponin T as a marker for cardiac involvement in acute TTP with clinical symptoms, electrocardiograms (ECG) and echocardiograms. A histopathological review of five patients who died of acute TTP was also undertaken. In 54% (22/41) of patients, troponin T was >or=0.05microg L(-1) (normal range 0-0.01 microg L(-1)). Half (12/22) had cardiac symptoms and 8/22 with a raised troponin T reported chest pain. ECG changes were present in 62% of patients with a raised troponin T. Median anti-ADAMTS 13 IgG antibody was significantly higher (P=0.018) in patients with troponin T>or=0.05 microg L(-1) (58.5% (range 17-162%), compared with patients with troponin T<0.05 microg L(-1) (35%, range 9-134%). Patients who died had higher troponin T levels (median 0.305 microg L(-1)) and raised anti-ADAMTS 13 IgG (median 66.5%). On admission, there were no deaths in those with troponin T<or=0.04microg L(-1). Histology confirmed widespread myocardial microvascular thrombi. Clinical symptoms, ECG changes and echocardiograms are poor predictors of cardiac disease in acute TTP. Troponin T is specific for cardiac muscle and a sensitive marker of myocardial damage. In TTP patients, raised levels (>or=0.05 microg L(-1)) signify myocardial necrosis associated with microvascular thrombi. Mortality and acute morbidity was associated with higher admission troponin T and raised IgG antibody (>67%) to ADAMTS 13.

Relationship Between Arterial Stiffness and Myocardial Damage in Patients With Newly Diagnosed Essential Hypertension

Arterial stiffness increases in hypertensive individuals. Arterial stiffness is associated with impairment of systolic and diastolic myocardial function in hypertension (HT). However, the relationship between arterial stiffness and serum heart-type fatty acid-binding protein (H-FABP) levels, a sensitive marker of myocardial damage, has not been previously examined in patients with HT. We investigate the relationship between serum H-FABP levels and arterial stiffness in patients with newly diagnosed HT. We studied 46 (48.5 +/- 10.6, years) never-treated patients with HT and age-matched control group of 40 (47 +/- 8.6, years) normotensive individuals. H-FABP levels were determined in all subjects. We evaluated arterial stiffness and wave reflections of study population, using applanation tonometry (Sphygmocor). Carotid-femoral pulse wave velocity (PWV) was measured as indices of elastic-type, aortic stiffness. The heart rate-corrected augmentation index (AIx@75) was estimated as a marker of wave reflections. Carotid-femoral PWV (10.5 +/- 2.2 vs. 8.7 +/- 1.6, m/s, P = 0.0001) and AIx@75 (22.7 +/- 9.5 vs. 15 +/- 11, %, P = 0.001) were significantly higher in patients with HT than control group. H-FABP levels were increased in hypertensive patients compared with control group (21.1 +/- 14.8 vs. 12.9 +/- 8.5, ng/ml, P = 0.002). In multiple linear regression analysis, we found that the body mass index (beta = 0.42, P = 0.0001) and carotid-femoral PWV (beta = 0.23, P = 0.03) were significant determinants of H-FABP levels. Arterial stiffness is associated with serum H-FABP levels, a sensitive marker of myocardial damage, in patients with newly diagnosed HT.

Cardiac troponin T content in heart and skeletal muscle and in blood samples from ApoE/LDL receptor double knockout mice

Background: The isolated perfused mouse heart is a useful experimental model, and cardiac troponin T (cTnT) in coronary effluent may be a sensitive marker of myocardial damage. In recent years, the apolipoprotein E/low-density lipoprotein receptor double knockout (apoE/LDLr KO) mice have become valuable tools in atherosclerosis research. The aim of the study was to validate measurements of cTnT in heart, skeletal muscle, and serum of apoE/LDLr KO mice. Methods: Wild-type C57BL/6J mice were fed with standard diet, and apoE/LDLr KO mice were fed an atherogenic diet. Blood was sampled from the jugular vein or the thoracic cavity. Heart and femoral skeletal muscle were sampled and homogenized. cTnT was measured with the third-generation cTnT assay (Troponin T STAT) on Elecsys 2010 immunoassay analyser (Roche Diagnostics). Results: Median serum cTnT in samples from the thoracic cavity of C57BL/6J mice was about 20–90 times higher, and from ApoE/LDLr KO mice about 30 times higher than serum cTnT in samples from the external jugular vein. There was no difference in cTnT content (μg cTnT/g heart muscle) in hearts from C57BL/6J and apoE/LDLr KO mice. The median cTnT content in skeletal muscle was less than 0.1% of the cTnT content in heart muscle. Conclusion: There is no difference in cTnT content of heart muscle comparing C57BL/6J and ApoE/LDLr KO mice, which have larger hearts. Sampling from the thoracic cavity causes unacceptably high cTnT levels. Serum cTnT in samples from the jugular vein is only slightly elevated. Elevated baseline levels of cTnT in mice are not caused by troponin T from skeletal muscle.

Serum myoglobin/carbonic anhydrase III ratio as a marker of reperfusion after myocardial infarction

Background: Coronary patency is important for short- and long-term outcome after myocardial infarction. Serum myoglobin concentration is a sensitive marker of myocardial damage and its specificity can be improved by simultaneous measurement of carbonic anhydrase III, a skeletal muscle marker. In the present study we evaluated the role of myoglobin/carbonic anhydrase III ratio as a non-invasive marker of reperfusion. Methods: We measured myoglobin, carbonic anhydrase III and creatine kinase MB-fraction release serially in 29 patients with acute myocardial infarction treated with thrombolysis and in 28 patients treated with primary coronary angioplasty. Results: Thrombolytic therapy was followed by a 9.1±2.2-fold increase in myoglobin and 10.8±3.3-fold increase in creatine kinase MB-fraction during the first hour of treatment, while carbonic anhydrase III remained unchanged. The peak value of myoglobin/carbonic anhydrase III ratio was found at 2 h and that of creatine kinase MB-fraction at 8 h after thrombolysis. Knowledge of the reperfusion time point during primary angioplasty and follow-up of cardiac markers revealed that cut-off points of 3 and 10 h for the peak values of myoglobin/carbonic anhydrase III ratio and creatine kinase MB-fraction can be used as indicators for reperfusion, respectively. Myoglobin/carbonic anhydrase III ratio measured before treatment and at 2 and 4 h after the onset of treatment screened 23 of those 25 patients with probable reperfusion after thrombolysis. Conclusions: We conclude that measuring myoglobin/carbonic anhydrase III ratio during the first hours after initiation of thrombolysis may be useful in evaluating the success of reperfusion after acute myocardial infarction.

Abstracts

Abstracts

Troponin-I for prediction of early postoperative course after pediatric cardiac surgery

OBJECTIVESIt was the aim of the study to test the prognostic value of cardiac troponin-I (cTnI) concerning the early postoperative course after pediatric cardiac surgery.BACKGROUNDCardiac troponin-I is a very specific and sensitive marker of myocardial damage in adults and children. As perioperative myocardial damage may be a significant factor of postoperative cardiac performance, serial cTnI values were analyzed in children undergoing open heart surgery.METHODSSeventy-three children undergoing elective correction of congenital heart disease including atrial and ventricular surgical manipulation were studied. Cardiac troponin-I levels were measured serially and correlated with intra- and postoperative parameters (such as doses and length of inotropic support, renal and hepatic function, duration of intubation). Patients with prolonged postoperative recovery were analyzed with special attention to the cTnI levels.RESULTSThe cutoff point for the definition of a high and a low risk group of cTnI values was set at 25 μg/liter, 4 h after admission to the intensive care unit (ICU) and at 35 μg/liter considering the maximal value of cTnI in the first 24 h in the ICU. The results showed a highly significant correlation between the need for inotropic support, the severity of renal dysfunction and the duration of intubation in relation to the serum levels of cTnI.CONCLUSIONSCardiac troponin-I serum levels after open heart surgery in children and infants 4 h after admission to the ICU allowed anticipation of the postoperative course and correlated with the incidence of significant postoperative complications.

Comparison of two strategies for myocardial management during coronary artery operations

Despite the current trend for using blood cardioplegia, ventricular fibrillation with intermittent ischemia is still used as a strategy to manage the myocardium with impressive results. These two methods of myocardial management were compared in 40 patients undergoing elective coronary artery operations using creatine kinase MB isoforms and troponin T assays. Each patient was randomized to have either cold blood cardioplegia (n = 20) or ventricular fibrillation with intermittent ischemia (n = 20) for myocardial management during the construction of distal anastomoses. Until recently, the comparison of different methods of myocardial management has been hindered by the lack of a specific and sensitive marker of myocardial damage. Analysis of creatine kinase MB isoforms (MB2, cardiac tissue form; MB1, plasma-modified form) and cardiac-specific troponin T (a structural protein) has been shown to improve the sensitivity for the detection of myocardial damage. There were no significant differences between the two groups in age, sex ratio, extent of disease, or left ventricular function. Blood samples for analysis were collected before cross-clamp application and at time intervals up to 48 hours after. Median peak creatine kinase MB2 activity was found to be significantly higher in the blood cardioplegia group compared with ventricular fibrillation (26.5 U/L versus 19.5 U/L, respectively, p = 0.04). Although median peak troponin T concentration was higher in the blood cardioplegia group, the difference failed to reach significance (22. ng/mL versus 1.6 ng/mL, p = 0.15). The area under the time-activity curves (a reflection of total release) constructed for creatine kinase MB, MB2, and troponin T were not significantly different between the groups ( p = 0.51, 0.82, and 0.31, respectively). These results suggest that, for elective coronary artery operations, ventricular fibrillation is as effective a strategy to manage the myocardium as blood cardioplegia and it may even be superior.