Clinical and hemodynamic characteristics of pulmonary hypertension associated with interstitial lung disease in China

Pulmonary vascular resistance predicts the mortality in patients with bronchiectasis-associated pulmonary hypertension

OBJECTIVE

Pulmonary hypertension is a severe complication of bronchiectasis, characterized by elevated pulmonary vascular resistance (PVR) and subsequent right heart failure. The association between PVR and mortality in bronchiectasis-associated pulmonary hypertension has not been investigated previously.

METHODS

In the present study, a retrospective analysis was conducted on 139 consecutive patients diagnosed with bronchiectasis-associated pulmonary hypertension based on right heart catheterization, enrolled between January 2010 and June 2023. Baseline clinical characteristics and hemodynamic assessment were analyzed. The survival time for each patient was calculated in months from the date of diagnosis until the date of death or, if the patient was still alive, until their last visit.

RESULTS

Patients with bronchiectasis-associated pulmonary hypertension exhibited estimated survival rates of 89.5, 70, and 52.9 at 1-year, 3-year, and 5-year intervals respectively, with a median survival time of 67 months. Multivariable Cox regression analysis revealed that increased age [(adjusted hazard ratio per year 1.042, 95% confidence interval (CI) 1.008-1.076, P  = 0.015] and elevated PVR (adjusted HR per 1 Wood Units 1.115, 95% CI 1.015-1.224, P  = 0.023) were associated with an increased risk of all-cause mortality. In contrast, higher BMI was associated with a decreased risk of all-cause death (adjusted hazard ratio per 1 kg/m 2 0.915, 95% CI 0.856-0.979, P  = 0.009). Receiver-operating characteristic analyses identified a cutoff value for PVR at 4 Wood Units as predictive for all-cause death within 3 years [area under the curve (AUC) = 0.624; specificity= 87.5%; sensitivity= 35.8%; P  < 0.05]. Patients with a PVR greater than 4 Wood Units had a significantly higher risk of all-cause death compared with those with 4 Wood Units or less (adjusted hazard ratio 2.392; 95% CI 1.316-4.349; P  = 0.019). Notably, there were no significant differences in age, sex, BMI, WHO functional class, 6-min walk distance, and NT-proBNP levels at baseline between patients categorized as having 4 Wood Units or less or greater than 4 Wood Units for PVR.

CONCLUSION

Based on these data, PVR could serve as a discriminative marker for distinguishing between nonsevere pulmonary hypertension (PVR ≤ 4 Wood Units) and severe pulmonary hypertension (PVR > 4 Wood Units). The utilization of a PVR cutoff value of 4.0 Wood Units provides enhanced prognostic capabilities for predicting mortality.

Outcomes of patients awaiting lung transplantation after the implementation of donation after brain death at a single Chinese center

Voluntary contribution has become the only source of donor lungs in China since 2015. To elaborate the outcomes of patients awaiting lung transplantation (LTx) after the implementation of donation after brain death, we performed a retrospective study that encompassed 205 patients with end-stage lung disease who registered for LTx at Shanghai Pulmonary Hospital from January 1, 2015 to January 1, 2021. A total of 180 patients were enrolled in the study. The median waiting time was 1.25 months. Interstitial lung disease (ILD) (103/180, 57.2%) and chronic obstructive pulmonary disease (COPD) (56/180, 31.1%) were the most common diseases in our study population. The mean pulmonary artery pressure (mPAP) of patients in the died-waiting group was higher than that of the survivors (53.29±21.71 mmHg vs. 42.11±18.58 mmHg, P=0.002). The mortality of patients with ILD (34/103, 33.00%) was nearly twice that of patients with COPD (10/56, 17.86%) while awaiting LTx (P=0.041). In the died-waiting group, patients with ILD had a shorter median waiting time than patients with COPD after being listed (0.865 months vs. 4.720 months, P=0.030). ILD as primary disease and mPAP > 35 mmHg were two significant independent risk factors for waitlist mortality, with hazard ratios (HR) of 3.483 (95% CI 1.311-9.111; P=0.011) and 3.500 (95% CI 1.435-8.536; P=0.006). Hence, LTx is more urgently needed in patients with ILD and pulmonary hypertension.

Lung Disease-Related Pulmonary Hypertension

Patients with advanced lung disease can develop pulmonary hypertension and succumb to right ventricular failure/cor pulmonale. Patients with pulmonary hypertension owing to chronic lung disease, or World Health Organization group 3 pulmonary hypertension, are more limited and carry a high risk of mortality. Adjunctive therapies remain the cornerstones of treatment. Recent evidence suggests that inhaled pulmonary vasodilator therapy can be helpful in patients with pulmonary hypertension owing to interstitial lung disease. Lung transplantation may be the only life-saving option in select patients, whereas palliative care and hospice should be sought for those who are not candidates as the disease progresses.

Prognostic value of 6-min walk stress echocardiography in patients with interstitial lung disease

BACKGROUND

The 6-min walk test (6MWT) provides prognostic information for patients with interstitial lung disease (ILD). Parameter determined by Doppler echocardiography after the 6MWT (6 MW stress echocardiography) is shown to be a predictor of future development of pulmonary hypertension in patients with connective tissue disease. However, the clinical utility of 6 MW stress echocardiography in predicting cardiopulmonary events in patients with ILD remains unknown. We examined whether parameters determined by 6 MW stress echocardiography independent predictors of adverse events in patients with ILD.

METHODS

Echocardiographic examinations were performed in 68 consecutively enrolled patients with ILD (age, 65 ± 10 years, 65% men). A pressure gradient of tricuspid regurgitation (TRPG) and pulmonary vascular resistance (PVRecho) calculated using the following formula [PVRecho = (peak velocity of TR × 10/time-velocity integral of right ventricular outflow (RVOT-VTI)) + 0.16] were measured at baseline and at post 6MWT. Data for parameters of pulmonary functional tests and for 6MWT were collected.

RESULTS

During a mean follow-up period of 22 ± 12 months, 22 patients experienced cardiopulmonary events. In univariate analysis, %VC, TRPG, PVRecho, TRPG post 6MWT, and PVRecho post 6MWT were significantly associated with cardiopulmonary events. Multivariate analysis using the Cox proportional hazards model indicated that %VC [hazard ratio (HR): 0.97, p = 0.009] and PVRecho post 6MWT (HR: 1.77, p = 0.004) were independent predictors of cardiopulmonary events in patients with ILD.

CONCLUSIONS

In addition to parameters of pulmonary function tests, increased PVRecho post 6MWT is a significant predictor of cardiopulmonary events in patients with ILD. A 6 MW stress echocardiography is useful in assessing the risk of adverse events in patients with ILD.

Predictive Value of Pulmonary Arterial Compliance in Systemic Lupus Erythematosus Patients With Pulmonary Arterial Hypertension

Pulmonary arterial hypertension is a serious complication of systemic lupus erythematosus. It is characterized by increased right ventricular afterload which mainly comprises pulmonary arterial compliance (PAC) and pulmonary vascular resistance. The role of PAC in predicting the outcome of systemic lupus erythematosus-associated pulmonary arterial hypertension has not been investigated yet. Between February 2012 to December 2016, 120 consecutive patients diagnosed with systemic lupus erythematosus-associated pulmonary arterial hypertension based on right heart catheterization were enrolled, prospectively. Baseline clinical characteristics and hemodynamic assessment were analyzed. Baseline right ventricular afterload was stratified according to the PAC and pulmonary vascular resistance. The end point was a composite of all-cause mortality and clinical worsening. Among them, end points occurred in 49 (41%) patients after 15 months (interquartile range, 8.5-24.0). Patients with a PAC <1.39 mL/mm Hg had a 3.09-fold higher risk (95% CI, 1.54-6.20, P=0.001) of the end point events than the patients with a PAC ≥1.39 mL/mm Hg. Multivariable Cox regression analysis showed that stratified right ventricular afterload was the only independent predictor for the end point (hazard ratio, 2.009 [95% CI, 1.390-2.904], P<0.001). A 3-group prediction risk was created. The patients with the highest right ventricular afterload (PAC <1.39 mL/mm Hg and pulmonary vascular resistance ≥10.3Wood Unit) had the highest risk (χ², 6.10; P<0.014) of experiencing the end point. Our results suggest that PAC is a good predictor of mortality and clinical worsening in systemic lupus erythematosus-associated pulmonary arterial hypertension. PAC, in addition to pulmonary vascular resistance, may be an attractive tool for screening high-risk populations in these patients.