Abstract: Objective　To investigate the relationship between low T3 syndrome and death or re-hospitalization in patients with pulmonary hypertension due to left heart disease（PH-LHD），and to estimate the value of low T3 syndrome in assessing the conditions and clinical outcomes of such patients.Methods　154 hospitalized PH-LHD patients from Beijing Anzhen Hospital，Capital Medical University were enrolled in 2015 and divided into a low T3 syndrome group（n=41） and a normal thyroid function group（n=113） according to their FT3 levels at admission.Baseline characteristics including laboratory findings were collected.All patients were given a telephone-based follow-up in January 2017，and events of death or re-hospitalization occurred between the discharge day and the follow-up day were evaluated.Results　In low T3 syndrome group， 2 cases were lost， and 6 cases were lost in normal thyroid function group.Compared with the normal thyroid function group，low T3 syndrome group demonstrated much higher re-hospitalization rate 〔61.5%（24/39） vs 41.1%（44/107） 〕（χ2=7.283，P=0.01），as well as significantly higher mortality〔46.2%（18/39） vs 15.9%（17/107） 〕（χ2=15.288，P<0.01）．Multivariate Cox regression analysis revealed that there was no significant correlation between low T3 syndrome and the re-hospitalization rate of PH-LHD patients 〔HR=0.849，95%CI（0.441，1.637），P=0.625〕，but BNP >400 ng/L 〔HR=2.496，95%CI（1.014，6.146），P=0.047〕 and low T3 syndrome 〔HR=2.353，95%CI（1.092，5.066），P=0.029〕 were the independent risk factors for death in PH-LHD patients.The area under the receiver operating characteristic curve（AUC） of FT3 was 0.759〔95%CI（0.664，0.854）〕 for predicting mortality，and the optimal cut-off point was found to be less than 4.195 pmol/L.The AUC of BNP was 0.800 〔95%CI（0.710，0.891）〕 for predicting mortality，and the best optimal cut-off point was identified to be greater than 600 ng/L.According to the DeLong test，there was no significant difference between the two AUCs（Z=0.693，P=0.488）．Conclusion　Low T3 syndrome is an independent risk factor for death in post-discharge PH-LHD patients.The routine detection of FT3 levels is of great significance to the risk stratification and prognosis assessment of PH-LHD patients.

Key words: Pulmonary hypertension due to left heart disease, Euthyroid sick syndromes, Death

摘要： 目的　分析低T3综合征与左心疾病相关肺动脉高压（PH-LHD）患者再住院及死亡事件之间的关系，探讨低T3综合征对PH-LHD患者病情评估及预后判断的价值。方法　选取2015年首都医科大学附属北京安贞医院收治的154例PH-LHD患者，根据其入院后首次测得游离三碘甲状腺原氨酸（FT3）水平分为低T3综合征组（n=41）及甲状腺功能正常组（n=113）。记录患者基本信息及实验室检查资料，并于2017年1月对患者进行电话随访，记录患者出院后到随访日期的再住院及死亡情况。结果　低T3综合征组失访2例，甲状腺功能正常组失访6例。低T3综合征组再住院24例（61.5%），死亡18例（46.2%）；甲状腺功能正常组再住院44例（41.1%），死亡17例（15.9%），低T3综合征组再住院率及死亡率均高于甲状腺功能正常组（χ2=7.283，P=0.01；χ2=15.288，P<0.01）。多因素Cox比例风险回归模型分析结果显示，低T3综合征与PH-LHD患者出院后再住院无明显相关性〔HR=0.849，95%CI（0.441，1.637），P=0.625〕；脑钠钛（BNP）>400 ng/L〔HR=2.496，95%CI（1.014，6.146），P=0.047〕和低T3综合征〔HR=2.353，95%CI（1.092，5.066），P=0.029〕是PH-LHD患者死亡的独立危险因素。血清FT3预测LH-PHD患者死亡的受试者工作特征（ROC）曲线下面积为0.759〔95%CI（0.664，0.854）〕，最佳临界值为FT3<4.195 pmol/L；BNP预测患者死亡的ROC曲线下面积为0.800〔95%CI（0.710，0.891）〕，最佳临界值为BNP>600 ng/L。DeLong检验结果显示，两者ROC曲线下面积比较，差异无统计学意义（Z=0.693，P=0.488）。结论　低T3综合征是PH-LHD患者出院后死亡的独立危险因素，常规检测FT3水平对PH-LHD患者进行危险分层及预后判断具有重要意义。

关键词: 左心疾病相关肺动脉高压, 功能正常甲状腺病综合征, 死亡