Marcadores de daño miocárdico en la predicción del pronóstico a corto plazo de los pacientes con COVID-19

Introduction and objectivesCOVID-19 is currently causing high mortality and morbidity worldwide. Information on cardiac injury is scarce. We aimed to evaluate cardiovascular damage in patients with COVID-19 and determine the correlation of high-sensitivity cardiac-specific troponin T (hs-cTnT) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) with the severity of COVID-19.MethodsWe included 872 consecutive patients with confirmed COVID-19 from February to April 2020. We tested 651 patients for high-sensitivity troponin T (hs-TnT) and 506 for NT-proBNP on admission. Cardiac injury was defined as hs-TnT > 14 ng/L, the upper 99th percentile. Levels of NT-proBNP > 300 pg/mL were considered related to some extent of cardiac injury. The primary composite endpoint was 30-day mortality or mechanical ventilation (MV).ResultsCardiac injury by hs-TnT was observed in 34.6% of our COVID-19 patients. Mortality or MV were higher in cardiac injury than noncardiac injury patients (39.1% vs 9.1%). Hs-TnT and NT-proBNP levels were independent predictors of death or MV (HR, 2.18; 95%CI, 1.23-3.83 and 1.87 (95%CI, 1.05-3.36), respectively) and of mortality alone (HR, 2.91; 95%CI, 1.211-7.04 and 5.47; 95%CI, 2.10-14.26, respectively). NT-ProBNP significantly improved the troponin model discrimination of mortality or MV (C-index 0.83 to 0.84), and of mortality alone (C-index 0.85 to 0.87).ConclusionsMyocardial injury measured at admission was a common finding in patients with COVID-19. It reliably predicted the occurrence of mortality and need of MV, the most severe complications of the disease. NT-proBNP improved the prognostic accuracy of hs-TnT.     

A mutation in the N-terminus of troponin I that is associated with hypertrophic cardiomyopathy affects the Ca(2+)-sensitivity, phosphorylation kinetics and proteolytic susceptibility of troponin

The first human cardiac troponin I (hcTnI) mutation in the N-terminal 32 residue region, R21C (arginine residue number 21 mutated to cysteine), which has been linked to hypertrophic cardiomyopathy (HCM), has recently been reported. The effect of this mutation on the physiological function of hcTnI was investigated. Human cTnI R21C (in the absence or presence of troponin T and troponin C) was phosphorylated by protein kinase A (PKA) at a significantly slower rate than wild-type hcTnI. In skinned fiber studies, the TnI R21C mutant showed a large increase in Ca(2+)-sensitivity of force development when compared to wild-type TnI (DeltapCa(50)=0.33). Phosphorylation of skinned fibers containing TnI R21C by PKA resulted in a significantly smaller decrease in the Ca(2+)-sensitivity of force development when compared to phosphorylation of fibers containing wild-type TnI. The decreased sensitivity of TnI R21C to PKA is most likely due to a decreased ability of PKA to phosphorylate this TnI rather than conformational problems within this TnI. In addition, skinned fibers were found to contain an endogenous kinase that is capable of phosphorylating wild-type TnI. However, the endogenous kinase activity did not affect the Ca(2+)-sensitivity of force development, the Hill coefficient or maximal force of these skinned fibers. Actomyosin ATPase assays showed that the R21C mutation did not affect the inhibitory properties of TnI or the maximal ATPase activity. TnI R21C was also found to be more susceptible to proteolysis by calpain II than wild-type TnI. These results suggest that this R21C mutation in TnI affects the Ca(2+)-sensitizing effect of Tn, the ability of TnI to be readily phosphorylated by PKA and the stability of TnI to calpain. The results also suggest that the N-terminal region may have important roles such as modulating the Ca(2+)-sensitivity of force-development.     

Prognostic value of high-sensitivity cardiac troponin T in patients with en-domyocardial-biopsy proven cardiac amyloidosis

Objective To investigate prognostic predictors of long-term survival of patients with cardiac amyloidosis （CA）, and to determine predictive value of high-sensitivity cardiac troponin T （hs-cTnT） in CA patients. Methods We recruited 102 consecutive CA cases and followed these patients for 5 years. We described their clinical characteristics at presentation and used a new, high-sensitivity assay to determine the concentration of cTnT in plasma samples from these patients. Results The patients with poor prognosis showed older age （56 ±12 years vs. 50 ±15 years, P=0.022）, higher incidences of heart failure （36.92%vs. 16.22%, P=0.041）, pericardial effusion （60.00%vs. 35.14%, P=0.023）, greater thickness of interventricular septum （IVS） （15 ±4 mm vs. 13 ±4 mm, P=0.034）, higher level of hs-cTnT （0.186 ±0.249 ng/mL vs. 0.044 ±0.055 ng/mL, P=0.001） and higher NT-proBNP （N-terminal pro-B-type natriuretic pep-tide） levels （11,742 ± 10,464 pg/mL vs. 6,031 ± 7,458 pg/mL, P=0.006）. At multivariate Cox regression analysis, heart failure （HR：1.78, 95%CI：1.09-2.92, P=0.021）, greater wall thickness of IVS （HR：1.44, 95%CI：1.04-3.01, P=0.0375） and higher hs-cTnT level （HR：6.16, 95%CI：2.20-17.24, P=0.001） at enrollment emerged as independent predictors of all-cause mortality. Conclusions We showed that hs-cTnT is associated with a very ominous prognosis, and it is also the strongest predictor of all-cause mortality in multivariate analysis. Examination of hs-cTnT concentrations provides valuable prognostic information concerning long-term outcomes.     

尼可地尔在持续性肌钙蛋白I弱阳性心绞痛患者中的作用

目的：探讨尼可地尔在持续性肌钙蛋白 I （TnI）弱阳性不稳定型心绞痛患者中的作用。方法：选择伴有持续性肌钙蛋白 I （TnI）弱阳性的不稳定性心绞痛患者111例,随机分为对照组（55例,接受常规治疗）和干预组（56例,在常规治疗基础上加用尼可地尔片（5mg,3次/d）;观察,比较两组患者治疗1周内胸痛缓解情况,3个月内因胸痛加重的再住院情况,1年内心源性死亡情况。结果：与对照组比较,干预组1周内两组症状缓解率显著上升（63.6％比91.1％,χ^2＝11.97,P＝0.0005）;3个月内胸痛加重再发住院显著减少（56.4％比19.6％,χ^2＝15.91,P＝0.0001）;但1年内两组心源性死亡率无显著差异（5.5％比8.9％,χ^2＝0.50,P＝0.4792）。结论：尼可地尔可明显改善持续性TnI弱阳性不稳定型心绞痛患者的症状,而且减少患者因心绞痛加重的再住院率,但一年内死亡率两组没有明显差别。     

肌钙蛋白及肌酸激酶同工酶与老年急性心肌梗死范围的相关性

目的：探讨心肌肌钙蛋白I（cTnI）、心肌肌钙蛋白T（cTnT）、肌酸激酶同工酶（CK-MB）的变化和老年心肌梗死（AMI）患者心肌梗死范围的相关性。方法：回顾性分析2012年9月至2013年9月于我院内科住院的80例老年心肌梗死患者的临床资料,分析治疗前和治疗1周后cTnI、cTnT、CK．MB值与心肌梗死范围的相关性。结果：与治疗前比较,治疗后患者cTnI[（4．63±0．21）／μg／L比（0．154±0．03）μg／L]、cTnT[（0．71±0．05）μg／L比（0．17±0．01）μg／L]、CK．MB[（40．21±2．13）U／L比（23．32±2．11）U／L]水平显著下降,心肌梗死面积[（35．25±4．65）mm。比（23．174±3．76）mm。]显著减小（P均〈0．01）;Pearson相关分析显示,cTnI、cTnT及CK—MB与心肌梗死面积均呈显著正相关（r=0．99、0．98、0．95,P均〈0．01）。结论：肌钙蛋白I、心肌肌钙蛋白T、肌酸激酶同工酶与心肌梗死范围关系密切,这三个指标值的结合可作为判断老年心肌梗死患者心肌梗死范围的重要依据。     

BNP、TnT水平对急性肺栓塞病情评估的临床意义

目的探讨脑钠肽(BNP)、肌钙蛋白T(Tn T)对急性肺栓塞(APE)病情评估的临床意义。方法选取2010年12月至2014年2月间首都医科大学大兴教学医院急诊科APE患者74例,男性42例,女性32例,年龄19~84岁,平均年龄(55.1±16.6)岁。根据BNP和Tn T水平分为3组,BNP+Tn T均阴性为A组40例,单纯BNP阳性为B组24例,BNP+Tn T均阳性为C组10例。测定所有患者BNP、Tn T水平;记录患者入院后症状缓解时间及住院总时间。结果与A组比较,B组发生晕厥的比例升高(2.5%vs.16.7%),与B组比较,C组发生晕厥的比例升高(16.7%vs.50.0%),差异具有统计学意义(P均0.05)。与B组比较,C组BNP水平升高,差异具有统计学意义(P0.05)。Tn T与住院总时间呈正相关(r=0.537,P0.05)。结论 BNP、TNT均是APE患者病情评估的重要指标,两者均升高的APE患者应积极处理。     

左卡尼汀对行PCI术的糖尿病患者心肌保护作用的研究

目的探讨冠心病(CHD)合并2型糖尿病(T2DM)患者经皮冠状动脉介入治疗(PCI)术前给予左卡尼汀(L-CN)对心肌损伤的保护作用。方法拟诊CHD合并T2DM并计划行冠状动脉造影的60例患者,随机分为两组,治疗组术前在标准治疗的基础上给予静脉滴注L-CN,对照组仅给予标准基础治疗。造影结果不适合行PCI治疗的病人被剔除,最终治疗组入选26例,对照组入选20例。所有患者术前及术后第24小时、1周测定心肌钙蛋白I(cTnI)和高敏CRP(hs-CRP)。结果总共46例患者PCI术后24小时和1周cTnI和hs-CRP均明显上升(P<0.01);但治疗组患者在术后24小时及术后1周血浆cTnI和hs-CRP水平均较对照组为低(P<0.05,P<0.01);直线相关分析显示,PCI术后24小时两组cTnI和hs-CRP水平显著正相关(r=0.75,P<0.01)。结论合并2型糖尿病的冠心病患者PCI治疗术后炎症反应和心肌损伤较为明显,PCI术前给予左卡尼汀可显著降低手术所致的心肌损伤,PCI引起的心肌坏死很可能与其触发的炎症反应有直接关系。     

急性心肌梗死患者冠状动脉循环血清高肌钙蛋白T含量变化及意义

目的研究急性心肌梗死（AMI）患者血清高敏肌钙蛋白T（hs-TnT）含量在冠状动脉循环中的变化。方法分别测定AMI患者与对照组冠状静脉窦、冠状动脉与外周血清中hs-TnT浓度。结果AMI患者冠状静脉窦、冠状动脉与外周静脉血清中hs-TnT浓度（μg／L）较对照组高,差异均有统计学意义（1．2842±1．0935比O．0069±0．0052、0．8594±0．7908比0．0072±0．0049、0．6682±0．7636比O．0068±O．0045）（P均〈0．01）。AMI患者冠状静脉窦血清hs-TnT浓度（μg／L）较冠状动脉血清hs-TnT明显升高,差异有统计学意义（1．2842±1．0935比0．8594±0．7908）（P〈0．01）。结论AMI患者外周静脉、冠状动脉和冠状静脉窦血清hs-TnT浓度明显升高,以冠状静脉窦血清ha-TnT升高最明显。     

High‐sensitive Troponin T measurements early after heart transplantation predict short‐ and long‐term survival

Following heart transplantation, cardiac biomarkers remain elevated for several weeks eventually as a result of membrane leakage of the donor organ. We now test the predictive power of blood levels of troponin T (TNT) measured by the new hsTNT assay (Roche Diagnostics, Roche Diagnostics, Mannheim, Germany) early after heart transplantation. TNT was determined in 141 cardiac allograft recipients and 40 controls. Our findings demonstrate that patients who died within the first year after transplantation had significantly higher median hsTNT serum levels 6 weeks after transplantation (156 ng/l ± 203 vs. 29 ng/l ± 21, P = 0.0002). Using ROC analysis, a serum hsTNT concentration of 33.55 ng/l 6 weeks after transplantation was found to be the best cutoff to predict death at 1 year (HR 0.16, 95%CI:0.05–0.46, P = 0.001) with a sensitivity of 90.91% and a specificity of 70.97%. In addition, survival at 5 years (HR 0.15, 95% CI 0.06–0.35, P < 0.0001) was significantly better among patients below that cutoff value. In multivariate analysis, hsTNT serum level 6 weeks after transplantation emerged as an independent predictor for first‐year mortality (hsTNT–HR 0.90, 95% CI: 0.81–1.00, P = 0.03). Cardiac troponin T concentrations early after transplantation as measured with a highly sensitive assay represent a strong and independent risk predictor of death after heart transplantation.