BACKGROUND: There is a paucity of information regarding prognostic factors associated with reduced survival in interstitial lung disease (ILD) patients without pulmonary hypertension (PH).
AIMS: The aim of this study was to determine physiological and hemodynamic parameters that impact survival among ILD patients without PH based on right heart catheterization (RHC).
METHODS: Consecutive ILD patients who underwent RHC (n = 169) at one center were included. The information analyzed included demographics and physiological and hemodynamic parameters. Cox regression models were used to identify independent predictors of survival.
RESULTS: The mean age was 55.0 years, and 49.7% of the patients were females. Thirty-three patients died, and two underwent transplantation. Patients with predicted diffusion capacity of the lung for carbon monoxide <35%, walking distance <300 m, and 6-min walk test (6MWT) final oxygen saturation measured by pulse oximetry (SpO₂) <85% were significantly associated with an increased mortality risk (P = 0.022, P < 0.0001, and P = 0.049, respectively; all by log-rank analysis). Advanced age, idiopathic pulmonary fibrosis diagnosis, reduced forced vital capacity, and low cardiac index were independent predictors of increased mortality in the ILD cohort.
CONCLUSIONS: Our study demonstrates that parameters obtained from baseline pulmonary function tests and 6MWTs are important determinants of survival in ILD patients without PH. Importantly, cardiac index was the only hemodynamic variable independently associated with survival. Thus, in the absence of PH, when ILD patients perform poorly during the 6MWT manifested as reduced walking distance and desaturation at the end of the test, cardiovascular impairment must be ruled out.


中文翻译：

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无肺动脉高压的间质性肺病患者的死亡率预测指标


背景：关于缺乏肺动脉高压（PH）的间质性肺病（ILD）患者存活率降低的预后因素，相关信息很少。
目的：本研究的目的是基于右心导管（RHC）确定影响无PH的ILD患者生存率的生理和血液动力学参数。
方法：纳入在一个中心接受RHC（n = 169）的连续ILD患者。分析的信息包括人口统计资料以及生理和血液动力学参数。使用Cox回归模型来确定生存的独立预测因子。
结果：平均年龄为55.0岁，其中49.7％为女性。33例患者死亡，其中2例接受了移植。一氧化碳的预测肺扩散能力<35％，步行距离<300 m，通过脉搏血氧饱和度（SpO ₂）测量的6分钟步行试验（6MWT）最终氧饱和度<85％的患者与增加死亡风险（分别为P = 0.022，P <0.0001和P = 0.049；全部通过对数秩分析）。高龄，特发性肺纤维化的诊断，强迫肺活量降低和心脏指数低是ILD队列死亡率增加的独立预测因素。
结论：我们的研究表明，从基线肺功能测试和6MWT获得的参数是无PH的ILD患者生存的重要决定因素。重要的是，心脏指数是唯一与生存相关的血液动力学变量。因此，在没有PH的情况下，当ILD患者在6MWT期间表现不佳时，表现为步行距离缩短和测试结束时的脱饱和，则必须排除心血管损害。