目的:急性心力衰竭(AHF)的高死亡率和严重并发症对住院患者构成重大威胁。这项研究的目的是确定入院时的低碳酸血症[定义为动脉二氧化碳分压(PaCO2)低于35mmHg]是否与AHF的住院全因死亡率有关。
结果:回顾性分析了在冠状动脉监护病房接受治疗的676例AHF患者,研究终点为院内全因死亡率.1:1倾向得分匹配(PSM)分析,卡普兰-迈耶曲线,和Cox回归模型用于探讨AHF患者低碳酸血症与院内全因死亡率之间的关系。使用受试者工作特征(ROC)曲线和Delong检验来评估低碳酸血症在预测AHF住院全因死亡率方面的表现。研究队列包括464名(68.6%)男性和212名(31.4%)女性,中位年龄为66岁(四分位距56-74岁).98例(14.5%)患者在住院期间死亡,低碳酸血症发生率高于幸存者(76.5%vs.45.5%,P<0.001)。在低碳酸血症和非低碳酸血症患者之间进行1:1PSM,匹配后两组各264人。与非低碳酸血症患者相比,前两种情况下,低碳酸血症患者的住院死亡率均显着较高(22.2%vs.6.8%,P<0.001)和之后(20.8%vs.8.7%,P<0.001)PSM。Kaplan-Meier曲线显示,PSM前后低碳酸血症患者住院死亡的概率明显较高(对数秩检验均P<0.001)。多因素Cox回归分析显示,在[风险比(HR)2.22;95%置信区间(CI)1.23-3.98;P=0.008]和(HR2.19;95%CI1.18-4.07;P=0.013)PSM之前,低碳酸血症是AHF死亡率的独立预测因素。Delong检验显示,在模型中加入低碳酸血症后,ROC曲线下面积得到改善(0.872,95%CI0.839-0.901vs.0.855,95%CI0.820-0.886,P=0.028)。PaCO2与估算的肾小球滤过率相关(r=0.20,P=0.001),左心室射血分数(r=0.13,P<0.001),B型利钠肽(r=-0.28,P<0.001),和乳酸(r=-0.15,P<0.001)。PaCO2tertiles的Kaplan-Meier曲线和多变量Cox回归分析显示,最低PaCO2tertile与AHF住院死亡率增加相关(均P<0.05)。
结论:低碳酸血症是AHF住院死亡率的独立预测因子。
Acute heart failure (AHF) poses a major threat to hospitalized patients for its high mortality rate and serious complications. The aim of this study is to determine whether
hypocapnia [defined as the partial pressure of arterial carbon dioxide (PaCO2 ) below 35 mmHg] on admission could be associated with in-hospital all-cause mortality in AHF.
A total of 676 patients treated in the coronary care unit for AHF were retrospectively analysed, and the study endpoint was in-hospital all-cause mortality. The 1:1 propensity score matching (PSM) analysis, Kaplan-Meier curve, and Cox regression model were used to explore the association between hypocapnia and in-hospital all-cause mortality in AHF. Receiver operating characteristic (ROC) curve and Delong\'s test were used to assess the performance of hypocapnia in predicting in-hospital all-cause mortality in AHF. The study cohort included 464 (68.6%) males and 212 (31.4%) females, and the median age was 66 years (interquartile range 56-74 years). Ninety-eight (14.5%) patients died during hospitalization and presented more
hypocapnia than survivors (76.5% vs. 45.5%, P < 0.001). A 1:1 PSM was performed between hypocapnic and non-hypocapnic patients, with 264 individuals in each of the two groups after matching. Compared with non-hypocapnic patients, in-hospital mortality was significantly higher in hypocapnic patients both before (22.2% vs. 6.8%, P < 0.001) and after (20.8% vs. 8.7%, P < 0.001) PSM. Kaplan-Meier curve showed a significantly higher probability of in-hospital death in patients with hypocapnia before and after PSM (both P < 0.001 for the log-rank test). Multivariate Cox regression analysis showed that
hypocapnia was an independent predictor of AHF mortality both before [hazard ratio (HR) 2.22; 95% confidence interval (CI) 1.23-3.98; P = 0.008] and after (HR 2.19; 95% CI 1.18-4.07; P = 0.013) PSM. Delong\'s test showed that the area under the ROC curve was improved after adding
hypocapnia into the model (0.872, 95% CI 0.839-0.901 vs. 0.855, 95% CI 0.820-0.886, P = 0.028). PaCO2 was correlated with the estimated glomerular filtration rate (r = 0.20, P = 0.001), left ventricular ejection fraction (r = 0.13, P < 0.001), B-type natriuretic peptide (r = -0.28, P < 0.001), and lactate (r = -0.15, P < 0.001). Kaplan-Meier curve of PaCO2 tertiles and multivariate Cox regression analysis showed that the lowest PaCO2 tertile was associated with increased risk of in-hospital mortality in AHF (all P < 0.05).
Hypocapnia is an independent predictor of in-hospital mortality for AHF.