Phosphodiesterase 5 inhibitor treatment and survival in interstitial lung disease pulmonary hypertension: A Bayesian retrospective observational cohort study.

BACKGROUND AND OBJECTIVE: Pulmonary hypertension is a life-limiting complication of interstitial lung disease (ILD-PH). We investigated whether treatment with phosphodiesterase 5 inhibitors (PDE5i) in patients with ILD-PH was associated with improved survival. METHODS: Consecutive incident patients with ILD-PH and right heart catheterisation, echocardiography and spirometry data were followed from diagnosis to death, transplantation or censoring with all follow-up and survival data modelled by Bayesian methods. RESULTS: The diagnoses in 128 patients were idiopathic pulmonary fibrosis (n = 74, 58%), hypersensitivity pneumonitis (n = 17, 13%), non-specific interstitial pneumonia (n = 12, 9%), undifferentiated ILD (n = 8, 6%) and other lung diseases (n = 17, 13%). Final outcomes were death (n = 106, 83%), transplantation (n = 9, 7%) and censoring (n = 13, 10%). Patients treated with PDE5i (n = 50, 39%) had higher mean pulmonary artery pressure (median 38 mm Hg [interquartile range, IQR: 34, 43] vs. 35 mm Hg [IQR: 31, 38], p = 0.07) and percentage predicted forced vital capacity (FVC; median 57% [IQR: 51, 73] vs. 52% [IQR: 45, 66], p=0.08) though differences did not reach significance. Patients treated with PDE5i survived longer than untreated patients (median 2.18 years [95% CI: 1.43, 3.04] vs. 0.94 years [0.69, 1.51], p = 0.003) independent of all other prognostic markers by Bayesian joint-modelling (HR 0.39, 95% CI: 0.23, 0.59, p < 0.001) and propensity-matched analyses (HR 0.38, 95% CI: 0.22, 0.58, p < 0.001). Survival difference with treatment was significantly larger if right ventricular function was normal, rather than abnormal, at presentation (+2.55 years, 95% CI: -0.03, +3.97 vs. +0.98 years, 95% CI: +0.47, +2.00, p = 0.04). CONCLUSION: PDE5i treatment in ILD-PH should be investigated by a prospective randomized trial.

Right Ventricular to Left Ventricular Ratio at CT Pulmonary Angiogram Predicts Mortality in Interstitial Lung Disease.

BACKGROUND: Patients with interstitial lung disease (ILD) may develop pulmonary hypertension (PH), often disproportionate to the severity of the ILD. The right ventricular to left ventricular diameter (RV:LV) ratio measured at CT pulmonary angiogram (CTPA) has been shown to provide valuable information in patients with pulmonary arterial hypertension and to predict death or deterioration in acute pulmonary embolism. METHODS: Demographic characteristics, ILD subtype, echocardiography, and detailed CTPA measurements were collected in consecutive patients undergoing both CTPA and right heart catheterization at the Royal Brompton Hospital between 2005 and 2015. Fibrosis severity was formally scored according to CT criteria. The RV:LV ratio at CTPA was evaluated by using three different methods. Cox proportional hazards analysis was used to assess the relation of CTPA-derived parameters to predict death or lung transplantation. RESULTS: A total of 92 patients were included (64% male; mean age 65 ± 11 years) with an FVC 57 ± 20% predicted, corrected transfer factor of the lung for carbon monoxide 22 ± 8% predicted, and corrected transfer coefficient of the lung for carbon monoxide 51 ± 17% predicted. PH was confirmed at right heart catheterization in 78%. Of all the CTPA-derived measures, an RV:LV ratio ≥ 1.0 strongly predicted mortality or transplantation at univariate analysis (hazard ratio, 3.26; 95% CI, 1.49-7.13; P = .003), whereas invasive hemodynamic data did not. The RV:LV ratio remained an independent predictor at multivariate analysis (hazard ratio, 3.19; 95% CI, 1.44-7.10; P = .004), adjusting for an ILD diagnosis of idiopathic pulmonary fibrosis and CT imaging-derived ILD severity. CONCLUSIONS: An increased RV:LV ratio measured at CTPA provides a simple, noninvasive method of risk stratification in patients with suspected ILD-PH. This should prompt closer follow-up, more aggressive treatment, and consideration of lung transplantation.

A stepwise composite echocardiographic score predicts severe pulmonary hypertension in patients with interstitial lung disease.

European Respiratory Society (ERS) guidelines recommend the assessment of patients with interstitial lung disease (ILD) and severe pulmonary hypertension (PH), as defined by a mean pulmonary artery pressure (mPAP) ≥35 mmHg at right heart catheterisation (RHC). We developed and validated a stepwise echocardiographic score to detect severe PH using the tricuspid regurgitant velocity and right atrial pressure (right ventricular systolic pressure (RVSP)) and additional echocardiographic signs. Consecutive ILD patients with suspected PH underwent RHC between 2005 and 2015. Receiver operating curve analysis tested the ability of components of the score to predict mPAP ≥35 mmHg, and a score devised using a stepwise approach. The score was tested in a contemporaneous validation cohort. The score used "additional PH signs" where RVSP was unavailable, using a bootstrapping technique. Within the derivation cohort (n=210), a score ≥7 predicted severe PH with 89% sensitivity, 71% specificity, positive predictive value 68% and negative predictive value 90%, with similar performance in the validation cohort (n=61) (area under the curve (AUC) 84.8% versus 83.1%, p=0.8). Although RVSP could be estimated in 92% of studies, reducing this to 60% maintained a fair accuracy (AUC 74.4%). This simple stepwise echocardiographic PH score can predict severe PH in patients with ILD.

Pulmonary hypertension in interstitial lung disease: Limitations of echocardiography compared to cardiac catheterization.

BACKGROUND AND OBJECTIVE: In interstitial lung disease (ILD), pulmonary hypertension (PH) is a major adverse prognostic determinant. Transthoracic echocardiography (TTE) is the most widely used tool when screening for PH, although discordance between TTE and right heart catheter (RHC) measured pulmonary haemodynamics is increasingly recognized. We evaluated the predictive utility of the updated European Society of Cardiology/European Respiratory Society (ESC/ERS) TTE screening recommendations against RHC testing in a large, well-characterized ILD cohort. METHODS: Two hundred and sixty-five consecutive patients with ILD and suspected PH underwent comprehensive assessment, including RHC, between 2006 and 2012. ESC/ERS recommended tricuspid regurgitation (TR) velocity thresholds for assigning high (>3.4 m/s), intermediate (2.9-3.4 m/s) and low (<2.8 m/s) probabilities of PH were evaluated against RHC testing. RESULTS: RHC testing confirmed PH in 86% of subjects with a peak TR velocity >3.4 m/s, and excluded PH in 60% of ILD subjects with a TR velocity <2.8 m/s. Thus, the ESC/ERS guidelines misclassified 40% of subjects as 'low probability' of PH, when PH was confirmed on subsequent RHC. Evaluating alternative TR velocity thresholds for assigning a low probability of PH did not significantly improve the ability of TR velocity to exclude a diagnosis of PH. CONCLUSION: In patients with ILD and suspected PH, currently recommended ESC/ERS TR velocity screening thresholds were associated with a high positive predictive value (86%) for confirming PH, but were of limited value in excluding PH, with 40% of patients misclassified as low probability when PH was confirmed at subsequent RHC.

Muddy clinical waters: a missed pulmonary embolus.

The diagnosis of pulmonary embolism (PE) can be difficult to make. The consequences of missing a PE can be fatal and clinicians should always be vigilant. This case presents a patient admitted with fluctuations in consciousness and in a septic state. A preliminary diagnosis of aspiration pneumonia was made, and the patient went on to have an exploratory surgical procedure with no remarkable findings. Only after further investigation of the patient's fluctuations in consciousness was a retrospective diagnosis of a large PE made. The patient was anticoagulated and made a full recovery, with no outstanding pulmonary issues at follow-up 6 weeks after discharge. A prolonged immobile state, likely in part due to the patient's septic state and psychiatric history, along with recent surgery and hospitalisation were the most obvious risk factors.