Predicting pulmonary hypertension in sarcoidosis; value of PH probability on echocardiography

Pulmonary Hypertension in Interstitial Lung Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Pulmonary hypertension (PH) is a key complication in interstitial lung disease (ILD), with recent therapeutic advances.

RESEARCH QUESTION

What are the diagnostic evaluation, epidemiologic features, associated factors, prognostic significance, and outcome measures in interventional trials for PH in patients with ILD in the current literature?

STUDY DESIGN AND METHODS

The Ovid MEDLINE, Embase, and CENTRAL databases were searched for original research evaluating PH in participants with ILD of any cause. The definition of PH was based on the investigators' criteria.

RESULTS

Three hundred two studies were included, with varying diagnostic evaluations used to define PH. Commonly used diagnostic tests were right heart catheterization (56%) and transthoracic echocardiography (50%). The pooled prevalence for PH in general populations with ILD was 36% (95% CI, 30%-42%) using right heart catheterization and 34% (95% CI, 29%-38%) using transthoracic echocardiography. Lower diffusion capacity of the lungs for carbon monoxide, worse oxygenation status, reduced exercise capacity, increased pulmonary artery to aorta ratio and pulmonary artery diameter, and elevated serum brain natriuretic peptide consistently were associated with the presence of PH in at least 60% of reported studies. The presence of PH was associated with increased symptom burden and worse prognosis. Outcome measures in interventional trials of PH in ILD focused on changes in pulmonary vascular hemodynamics and 6-min walk distance.

INTERPRETATION

PH is a common complication in ILD with significant health impacts. A standardized definition with prospective evaluation of risk-stratified assessments for PH using identified associated risk factors is warranted. Our findings provide an evidence base for validation as surrogate end points in future PH interventional trials in ILD.

TRIAL REGISTRY

International Prospective Register of Systematic Reviews; No.: CRD42021255394; URL: https://www.crd.york.ac.uk/prospero/.

Sarcoidosis-Associated Pulmonary Hypertension

Sarcoidosis-associated pulmonary hypertension (SAPH) is a very severe complication of the disease, largely impacting its morbidity and being one of its strongest predictors of mortality. With the recent modifications of the hemodynamic definition of pulmonary hypertension (mean arterial pulmonary pressure >20 instead of <25 mmHg,) its prevalence is presently not precisely known, but it affects from 3 to 20% of sarcoid patients; mostly, although not exclusively, those with an advanced, fibrotic pulmonary disease. Its gold-standard diagnostic tool remains right heart catheterization (RHC). The decision to perform it relies on an expert decision after a non-invasive work-up, in which echocardiography remains the screening tool of choice. The mechanisms underlying SAPH, very often entangled, are crucial to define, as appropriate and personalized therapeutic strategies will aim at targeting the most significant ones. There are no recommendations so far as to the indications and modalities of the medical treatment of SAPH, which is based upon the opinion of a multidisciplinary team of sarcoidosis, pulmonary hypertension and sometimes lung transplant experts.

A Systematic Review of Echocardiographic Parameters for the Screening of Pulmonary Hypertension: What Are the Odds?

Pulmonary hypertension (PH) is an insidious disease that often presents in late stages due to nonspecific signs and symptoms. Right heart catheterization (RHC) is the gold standard diagnostic test, and echocardiogram (ECHO) is the best screening tool. However, the strength of evidence and diagnostic utility of various echocardiographic parameters to screen for is not well elucidated. This systematic review (SR) is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Literature searches was performed for the period of January 1, 2016, to June 1, 2021, on seven databases. We included full-text studies with adult patients that used RHC for comparison and provided sensitivity and specificity results. Likelihood ratios (LRs) and diagnostic odds ratios (DORs) were calculated. Risk of bias was assessed using the Quality Assessment Tool for the Observational Cohort and Cross-Sectional Studies. We identified 102 studies, but only 14 satisfied our inclusion criteria. The most significant parameters identified for PH screening based on LRs are, in descending order, tricuspid regurgitation gradient peak >36mmHg, systolic pulmonary artery pressure >41mmHg, and tricuspid regurgitation velocity >2.9 m/s. There is strong correlation between LR and DOR for these parameters. This SR indicates the superiority of some ECHO parameters over others to aid in the screening and severity assessment of PH. Variables with low LR (-) ratios may help to prevent unnecessary invasive assessment for PH. Clinicians should utilize a multi-parameter approach when interpreting echocardiograms for PH assessment.

Prevalence of Sarcoidosis-Associated Pulmonary Hypertension: A Systematic Review and Meta-Analysis

Background

Sarcoidosis-associated pulmonary hypertension (SAPH) is associated with poor prognosis, conferring up to a 10-fold increase in mortality in patients with sarcoidosis, but the actual prevalence of SAPH is unknown.

Methods

The PubMed, Embase, and Cochrane Library databases were systematically searched for epidemiological studies reporting the prevalence of SAPH up to July 2021. Two reviewers independently performed the study selection, data extraction, and quality assessment. Studies were pooled using random-effects meta-analysis.

Results

This meta-analysis included 25 high-quality studies from 12 countries, with a pooled sample of 632,368 patients with sarcoidosis. The prevalence of SAPH by transthoracic echocardiography in Europe, the United States and Asia was 18.8% [95% confidence interval (CI): 11.1–26.5%], 13.9% (95% CI: 5.4–22.4%) and 16.2% (95% CI: 7.1–25.4%) separately, and the overall pooled prevalence was 16.4% (95%CI: 12.2–20.5%). By right heart catheterization (RHC), the pooled prevalence of SAPH was 6.4% (95% CI: 3.6–9.1%) in general sarcoidosis population, and subgroup analyses showed that the prevalence of SAPH was 6.7% (95% CI: 2.4–11.0%) in Europe and 8.6% (95% CI: −4.1 to 21.3%) in the United States. Further, the prevalence of pre-capillary PH was 6.5% (95% CI: 2.9–10.2%). For the population with advanced sarcoidosis, the pooled prevalence of SAPH and pre-capillary PH by RHC was as high as 62.3% (95% CI: 46.9–77.6%) and 55.9% (95% CI: 20.1–91.7%), respectively. Finally, the pooled prevalence of SAPH in large databases with documented diagnoses (6.1%, 95% CI: 2.6–9.5%) was similar to that of RHC. Substantial heterogeneity across studies was observed for all analyses (I² > 80%, P < 0.001).

Conclusions

The sarcoidosis population has a relatively low burden of PH, mainly pre-capillary PH. However, as the disease progresses to advanced sarcoidosis, the prevalence of SAPH increases significantly.

Sarcoidosis associated pulmonary hypertension: an update

PURPOSE OF REVIEW

Sarcoidosis associated pulmonary hypertension (SAPH) is a well-recognised complication, associated with a seven-fold increase in mortality. This comprehensive review will summarise these recent developments and proposes the use of a phenotype-based management approach in SAPH.

RECENT FINDINGS

Recent registry-based studies have highlighted the adverse outcomes associated with SAPH and shown that reduced 6-min walk distance and diffusion capacity for carbon monoxide are predictive of poor prognosis. There is increasing interest in methods for early detection of SAPH, although whether early diagnosis impacts on survival remains uncertain. The pathophysiology underpinning SAPH is complex and often incorporates multiple mechanisms. Once the diagnosis is confirmed, understanding the underlying phenotypes of SAPH is key to providing the most effective management plan. There is some evidence that treating patients with precapillary PH with pulmonary vasodilators may improve some haemodynamic and quality life measures. However, more work is needed to determine whether mortality is affected.

SUMMARY

SAPH is associated with worsened survival. A range of phenotypes are recognised in SAPH. Multimodality risk assessment in patients with SAPH is likely to be important and is an area that requires further work. Published evidence for pulmonary vasodilator therapies in SAPH with a Pulmonary arterial hypertension-like phenotype is encouraging so far, but multiple confounding factors affects the quality of the evidence. The role of immunosuppressive agents for improving pulmonary pressures is unclear. Urgent controlled trials are needed.

Sarcoidosis-Associated Pulmonary Hypertension

Pulmonary hypertension (PH) is a well-known complication of sarcoidosis, defined by a mean pulmonary artery pressure of ≥25 mm Hg. Since both PH and sarcoidosis are rare diseases, data on sarcoidosis-associated PH (SAPH) is retrieved mostly from small retrospective studies. Estimated prevalence of SAPH ranges from 3% in patients referred to a tertiary center up to 79% in patients awaiting lung transplant. Most patients with SAPH show advanced parenchymal disease as the underlying mechanism. However, some patients have disproportional elevated pulmonary artery pressure, and PH can occur in sarcoidosis patients without parenchymal disease. Other mechanisms such as vascular disease, pulmonary embolisms, postcapillary PH, extrinsic compression, and other sarcoidosis-related comorbidities might contribute to SAPH. The diagnosis of PH in sarcoidosis is challenging since symptoms and signs overlap. Suspicion can be raised based on symptoms or tests, such as pulmonary function tests, laboratory findings, electrocardiography, or chest CT. PH screening mainly relies on transthoracic echocardiography. Right heart catheterization should be considered on a case-by-case basis in patients with clinical suspicion of PH, taking into account clinical consequences. Treatment options are considered on patient level in a PH expert center, and might include oxygen therapy, immunosuppressive, or PH-specific therapy. However, qualitative evidence is scarce. Furthermore, in a subset of patients, interventional therapy or eventually lung transplant can be considered. SAPH is associated with high morbidity. Mortality is higher in sarcoidosis patients with PH compared with those without PH, and increases in patients with more advanced stages of sarcoidosis and/or PH.