Abstract：
OBJECTIVE: Chronic myocardial injury (CMI) is defined as stable concentrations of cardiac troponin T or I (cTnT or cTnI) above the assay-specific 99th percentile upper reference limit (URL) and signals poor outcome. The clinical implications of diagnosing CMI are unclear. We aimed to assess prevalence and association of CMI with long-term prognosis using three different high-sensitivity cTn (hs-cTn) assays.
METHODS: A total of 1,292 hospitalized patients without acute myocardial injury had cTn concentrations quantified by hs-cTn assays by Roche Diagnostics, Abbott Diagnostics and Siemens Healthineers. The median follow-up time was 4.1 years. The prevalence of CMI and hazard ratios for mortality and cardiovascular (CV) events were calculated based on the URL provided by the manufacturers and compared to the prognostic accuracy when lower percentiles of cTn (97.5, 95 or 90), limit of detection or the estimated bioequivalent concentrations between assays were used as cutoff values.
RESULTS: There was no major difference in prognostic accuracy between cTnT and cTnI analyzed as continuous variables. The correlation between cTnT and cTnI was high (r=0.724-0.785), but the cTnT assay diagnosed 3.9-4.5 times more patients with having CMI based on the sex-specific URLs (TnT, n=207; TnI Abbott, n=46, TnI Siemens, n=53) and had higher clinical sensitivity and AUC at the URL.
CONCLUSIONS: The prevalence of CMI is highly assay-dependent. cTnT and cTnI have similar prognostic accuracy for mortality or CV events when measured as continuous variables. However, a CMI diagnosis according to cTnT has higher prognostic accuracy compared to a CMI diagnosis according to cTnI.
METHODS: A total of 1,292 hospitalized patients without acute myocardial injury had cTn concentrations quantified by hs-cTn assays by Roche Diagnostics, Abbott Diagnostics and Siemens Healthineers. The median follow-up time was 4.1 years. The prevalence of CMI and hazard ratios for mortality and cardiovascular (CV) events were calculated based on the URL provided by the manufacturers and compared to the prognostic accuracy when lower percentiles of cTn (97.5, 95 or 90), limit of detection or the estimated bioequivalent concentrations between assays were used as cutoff values.
RESULTS: There was no major difference in prognostic accuracy between cTnT and cTnI analyzed as continuous variables. The correlation between cTnT and cTnI was high (r=0.724-0.785), but the cTnT assay diagnosed 3.9-4.5 times more patients with having CMI based on the sex-specific URLs (TnT, n=207; TnI Abbott, n=46, TnI Siemens, n=53) and had higher clinical sensitivity and AUC at the URL.
CONCLUSIONS: The prevalence of CMI is highly assay-dependent. cTnT and cTnI have similar prognostic accuracy for mortality or CV events when measured as continuous variables. However, a CMI diagnosis according to cTnT has higher prognostic accuracy compared to a CMI diagnosis according to cTnI.
摘要：
目的：慢性心肌损伤（CMI）定义为心肌肌钙蛋白T或I（cTnT或cTnI）的稳定浓度高于测定特异性第99百分位数参考上限（URL），并且信号结果较差。诊断CMI的临床意义尚不清楚。我们旨在使用三种不同的高灵敏度cTn（hs-cTn）测定法评估CMI的患病率和与长期预后的关联。
方法：共有1,292例无急性心肌损伤的住院患者通过罗氏诊断的hs-cTn测定定量的cTn浓度，雅培诊断和西门子Healthineers。中位随访时间为4.1年。根据制造商提供的URL计算CMI的患病率以及死亡率和心血管（CV）事件的风险比，并与cTn较低百分位数（97.5、95或90）时的预后准确性进行比较。检测限或测定之间的估计生物等效浓度用作截止值.
结果：作为连续变量分析的cTnT和cTnI之间的预后准确性没有重大差异。cTnT与cTnI的相关性较高(r=0.724-0.785),但是cTnT检测根据性别特异性URL诊断出患有CMI的患者多3.9-4.5倍(TnT，n=207；TnIAbbott，n=46，TnI西门子，n=53），在URL处具有更高的临床敏感性和AUC。
结论：CMI的患病率高度依赖于分析。当作为连续变量测量时,cTnT和cTnI对死亡率或CV事件具有相似的预后准确性。然而,与根据cTnI的CMI诊断相比,根据cTnT的CMI诊断具有更高的预后准确性.
方法：共有1,292例无急性心肌损伤的住院患者通过罗氏诊断的hs-cTn测定定量的cTn浓度，雅培诊断和西门子Healthineers。中位随访时间为4.1年。根据制造商提供的URL计算CMI的患病率以及死亡率和心血管（CV）事件的风险比，并与cTn较低百分位数（97.5、95或90）时的预后准确性进行比较。检测限或测定之间的估计生物等效浓度用作截止值.
结果：作为连续变量分析的cTnT和cTnI之间的预后准确性没有重大差异。cTnT与cTnI的相关性较高(r=0.724-0.785),但是cTnT检测根据性别特异性URL诊断出患有CMI的患者多3.9-4.5倍(TnT，n=207；TnIAbbott，n=46，TnI西门子，n=53），在URL处具有更高的临床敏感性和AUC。
结论：CMI的患病率高度依赖于分析。当作为连续变量测量时,cTnT和cTnI对死亡率或CV事件具有相似的预后准确性。然而,与根据cTnI的CMI诊断相比,根据cTnT的CMI诊断具有更高的预后准确性.
