Does rheumatic myocarditis really exists? Systematic study with echocardiography and cardiac troponin I blood levels.

AIMS: Revised guidelines for diagnosis of rheumatic fever indicate that rheumatic myocarditis may 'contribute' to the genesis of congestive heart failure. Our objective was to assess non-invasively the presence of non-clinical markers of myocardial involvement in acute rheumatic fever. METHODS: Echocardiography and assessment of cardiac troponin I (cTnI) blood levels were systematically performed in 95 consecutive patients with acute rheumatic fever, who were divided into three groups. Group 1: patients without carditis (n=22); group 2: patients with carditis and without congestive heart failure (n=59); group 3: patients with carditis and congestive heart failure (n=14). RESULTS: Left ventricular ejection fraction was normal in all patients and did not differ between groups (group 1: 0.72+/-0.08, group 2: 0.69+/-0.06, and group 3: 0.66+/-0.07, p=0.09). Left ventricular diameters tend to be larger in group 3, but all patients had severe mitral and/or aortic regurgitation. Mean cTnI was 0.077+/-0.017 ng/ml (normal <0.1 ng/ml), did not differ between groups (p=0.45), and only 13 patients (seven with pericardial effusion) had detectable levels (0.2-0.4 ng/ml). CONCLUSIONS: Our study neither detected cTnI elevations nor echocardiographic abnormalities suggesting significant myocardial involvement during rheumatic fever. Congestive heart failure was always associated to severe valve regurgitation.     

实验性肺炎大鼠肌钙蛋白T的变化及其与心脏收缩功能的关系

目的探讨实验性肺炎大鼠血清肌钙蛋白T(cTnT)的变化及其与心脏收缩功能的关系,以明确肺炎是否可引起心肌受损,以及发生心肌受损的机理。方法建立金黄色葡萄球菌肺炎大鼠模型后第5天行经胸超声心动图检查。测量指标:左室舒张末内径(LVDD)、左室收缩末内径(LVSD)、主动脉血流峰值流速(PFVA)、主动脉血流速度积分(Viao)、肺动脉血流峰值流速(PFVP)、肺动脉血流速度积分(Vipa),并计算左室射血分数(LVEF)、左室短轴缩短率(LVFS)。采用酶联免疫吸附法检测大鼠血清cTnT的水平,并分析cTnT与心脏收缩功能的关系。结果肺炎组大鼠与对照组比较,PFVA、PFVP、Viao、Vipa、LVEF、LVFS显著减少(P均<0.01)。肺炎组大鼠血清cTnT水平显著高于对照组,且与LVEF、LVFS呈负相关(P均<0.05)。结论严重金黄色葡萄球菌肺炎可引起心力衰竭,其发生机理与心肌损害和肺动脉高压有关。血清cTnT可作为诊断心肌受损的生化指标。     

心肌肌钙蛋白I在心脏移植术后恢复及排斥反应中的意义

目的对19例心脏移植受体术后早期及定期行心肌肌钙蛋白I(cardiactroponinI,cTnI)检测,探讨cTnI在心脏移植术后恢复及排斥反应中的作用。方法(1)对19例心脏移植受体术后1个月内每日行cTnI检测;(2)对存活的心脏移植受体每3个月或发现急性排斥反应时行cTnI检测。结果(1)19例心脏移植术后1个月内恢复顺利的患者其心肌cTnI的下降速度均较快,心脏移植后8天内均下降至10μg/L以下,20天内降至正常,而死亡5例患者中早期死亡的3例其cTnI在术后10天后仍维持在较高水平;(2)14例存活的心脏移植受体定期复查cTnI均正常,其中4例心肌活检病理确诊为Ⅱ级以上急性排斥反应患者,不论出现急性排斥反应的级别高低,其cTnI均未见升高。结论cTnI对心脏移植早期恢复评定具有重要意义,而与急性排斥反应无明显相关性。     

Changes of Lipid Profile and C-Reactive Protein after Withdrawal of Xuezhikang,an Extract of Cholestin,in Patients With Stable Angina Pectoris

Lipid-lowering therapy using HMG-CoA reductase inhibitors (statins) has been shown to assist in the prevention of cardiovascular events in many clinical trials[1-3]. Statins may also have an abundance of pleiotropic effects[4-7]. C-reactive protein (CRP),…     

肌钙蛋白I对无ST段抬高的急性冠状动脉综合征患者危险分层的判断

目的 :探讨血清肌钙蛋白I(cTnI)对无ST段抬高的急性冠状动脉综合征 (NSTEACS)患者危险分层的判断价值。方法 :对 4 2例NSTEACS患者、16例健康者分别进行血清cTnI测定 ,并观察住院 1个月内心脏事件发生情况。结果 :NSTEACS组血清cTnI值为 (1.98± 0 .11) μg/L ,明显高于正常对照组的 (0 .4 9± 0 .10 ) μg/L ,P <0 .0 1。NSTEACS组内 ,心肌梗死者 (cTnI阳性亚组 )血清cTnI值为 (2 .85± 0 .6 7) μg/L ,明显高于不稳定型心绞痛者 (cTnI阴性亚组 )的 (0 .73± 0 .16 ) μg/L ,P <0 .0 1。正常对照组无一例发生心脏事件 ;cTnI阳性亚组心脏事件发生率为 2 0 .8% ,高于cTnI阴性亚组的 5 .5 % (P <0 .0 5 ) ,比数比 (OR) 3.78,95 %可信度为 1.0 4～ 9.87。血清cTnI≥ 1.5 μg/L时判断心脏事件的阳性预测值为2 0 .8% ,阴性预测值为 94 .5 %。结论 :血清cTnI检测对NSTEACS患者危险分层有较好的判断价值     

Biochemistry tests in hospitalized COVID-19 patients: Experience from a Canadian tertiary care centre

BackgroundCoronavirus Disease 2019 (COVID-19) has variable clinical presentation, from asymptomatic to severe disease leading to death. Biochemical markers may help with management and prognostication of COVID-19 patients; however, their utility is still under investigation.MethodsA retrospective study was conducted to evaluate alanine aminotransferase, C-reactive protein (CRP), ferritin, lactate, and high sensitivity troponin T (TnT) levels in 67 patients who were admitted to a Canadian tertiary care centre for management of COVID-19. Logistic, cause-specific Cox proportional-hazards, and accelerated failure time regression modelling were performed to assess the associations of initial analyte concentrations with in-hospital death and length of stay in hospital; joint modelling was performed to assess the associations of the concentrations over the course of the hospital stay with in-hospital death.ResultsInitial TnT and CRP concentrations were associated with length of stay in hospital. Eighteen patients died (27%), and the median initial TnT concentration was higher in patients who died (55 ng/L) than those who lived (16 ng/L; P < 0.0001). There were no survivors with an initial TnT concentration > 64 ng/L. While the initial TnT concentration was predictive of death, later measurements were not. Only CRP had prognostic value with both the initial and subsequent measurements: a 20% increase in the initial CRP concentration was associated with a 14% (95% confidence interval (CI): 1–29%) increase in the odds of death, and the hazard of death increased 14% (95% CI: 5–25%) for each 20% increase in the current CRP value. While the initial lactate concentration was not predictive of death, subsequent measurements were.ConclusionCRP, lactate and TnT were associated with poorer outcomes and appear to be useful biochemical markers for monitoring COVID-19 patients.     

Implementing Point-of-Care Troponin Testing in the Emergency Department: Impact on Time to Result

IntroductionIn the emergency department, troponin assays are commonly used and essential in the evaluation of chest pain and diagnosis of acute coronary syndrome. This study was designed to assess the potential impact of implementing point-of-care troponin testing by comparing the time to point-of-care laboratory result and time to conventional laboratory result.MethodsThe study enrolled 60 ED patients deemed to need a troponin test in the evaluation of low-risk chest pain (HEART score <4 based on history, electrocardiogram, age, risk factors). Point-of-care troponin testing was performed with the same blood sample obtained for a conventional troponin assay. If the provider determined that the patient required 2 troponin tests, the second laboratory draw was used in the data collection. This was to correlate the time of laboratory result to time of disposition.ResultsOf the 60 subjects enrolled, 2 subjects were excluded because of user errors with the point-of-care testing equipment and 2 others for not meeting inclusion criteria on later review. The median times for the point-of-care troponin and conventional troponin assays were 11:00 minutes (interquartile range 10:00-15:30) and 40:00 minutes (interquartile range 31:30-52:30), respectively; P < 0.001. There were 3 extreme outliers from the conventional troponin assay that significantly skewed the distribution of the mean, making the median the more accurate assessment of the central tendency.DiscussionPoint-of-care troponin testing provided results in a median time 29 minutes quicker than the conventional troponin assay. This result is statistically significant and has the potential to greatly improve time to disposition in all patients with chest pain requiring a troponin assay.     

Influence of maturational status in the exercise-induced release of cardiac troponin T in healthy young swimmers

ObjectivesTo determine the influence of maturational status on the release of cardiac troponin T (cTnT) induced by a bout of 30 min, high-intensity, continuous exercise.DesignQuasi-experimental, cross-sectional study.MethodsSeventy male, young, well trained swimmers (age range 7–18 years, training experience 1–11 years) were classified by maturational stages: Tanner stage I (n = 14), II (n = 15), III (n = 15), IV (n = 13), and V (n = 13). Participants underwent a distance-trial of 30 min continuous swimming, and cTnT was measured before, immediately after and 3 h after exercise. Changes in cTnT over time were compared among groups, and associated with exercise load.ResultsBasal cTnT was higher in Tanner-V (3.8–8.1 ng/L) compared with I (1.5–5.5 ng/L, p < 0.001), II (1.5–4.5 ng/L, p < 0.001) and III (1.5–6.8 ng/L, p = 0.003), and in IV (1.5–6.3 ng/L) compared with II (p = 0.036). Maximal elevations of cTnT from baseline were notable (p < 0.001) and comparable among maturational stages (p = 0.078). The upper reference limit for myocardial injury was exceeded in 35.7% of the participants, without differences among groups (p = 0.18). Baseline cTnT correlated with participant characteristics, and maximal cTnT elevations from baseline with exercise internal load (%HRpeak, r_s = 0.34, p =  0.003; %HRmean, r_s = 0.28, p = 0.02).ConclusionsMaturational status influences positively absolute pre- and post-exercise cTnT but not its elevation after a bout of 30 min, high-intensity, continuous exercise.     

Evaluation of Heart-type Fatty Acid-binding Protein in Early Diagnosis of Acute Myocardial Infarction

BackgroundAlthough electrocardiography and cardiac troponin play important roles in the diagnosis of acute coronary syndrome (ACS), there remain unmet clinical needs. Heart-type fatty acid-binding protein (H-FABP) has been identified as an early diagnostic marker of acute myocardial infarction (AMI). In this study, we examined the diagnostic and prognostic value of H-FABP in patients suspected with ACS.MethodsWe conducted an observational single-center cohort study, including 89 adults aged 30 years or older, who presented to the emergency room (ER) within 24 hours after the onset of chest pain and/or dyspnea. We performed laboratory analysis and point-of-care testing (POCT) for cardiac markers, including H-FABP, troponin I, and creatine kinase-myocardial band. We also evaluated the correlation between cardiac markers and left ventricular (LV) dysfunction and extent of coronary artery disease (CAD).ResultsIn patients presented to ER within 4 hours after symptom onset (n = 49), the diagnostic accuracy of H-FABP for AMI, as quantified by the area under the receiver operating characteristic curve, was higher (0.738; 95% confidence interval [CI], 0.591–0.885) than other cardiac markers. In POCT, the diagnostic accuracy of H-FABP (56%; 95% CI, 45–67) was significantly higher than other cardiac markers. H-FABP was correlated with not extent of CAD but post-AMI LV dysfunction.ConclusionH-FABP is a useful cardiac marker for the early diagnosis of AMI and prediction of myocardia injury. Difference in the circulatory release timeline of cardiac markers could explain its utility in early-stage of myocardial injury.