Outcomes of patients with decreased arterial oxyhaemoglobin saturation on pulmonary arterial hypertension drugs

Prognostic Value of Serial Risk Stratification in Adult and Pediatric Pulmonary Arterial Hypertension: A Systematic Review

BACKGROUND

In pulmonary arterial hypertension, it is recommended to base therapeutic decisions on risk stratification. This systematic review aims to report the prognostic value of serial risk stratification in adult and pediatric pulmonary arterial hypertension and to explore the usability of serial risk stratification as treatment target.

METHODS AND RESULTS

Electronic databases PubMed, Embase, and Web of Science were searched up to January 30, 2023, using terms associated with pulmonary arterial hypertension, pediatric pulmonary hypertension, and risk stratification. Observational studies and clinical trials describing risk stratification at both baseline and follow-up were included. Sixty five studies were eligible for inclusion, including only 2 studies in a pediatric population. C-statistic range at baseline was 0.31 to 0.77 and improved to 0.30 to 0.91 at follow-up. In 53% of patients, risk status changed (42% improved, 12% worsened) over 168 days (interquartile range, 137-327 days; n=22 studies). The average proportion of low-risk patients increased from 18% at baseline to 36% at a median follow-up of 244 days (interquartile range, 140-365 days; n=40 studies). In placebo-controlled drug studies, risk statuses of the intervention groups improved more and worsened less compared with the placebo groups. Furthermore, a low-risk status, but also an improved risk status, at follow-up was associated with a better outcome. Similar results were found in the 2 pediatric studies.

CONCLUSIONS

Follow-up risk stratification has improved prognostic value compared with baseline risk stratification, and change in risk status between baseline and follow-up corresponded to a change in survival. These data support the use of serial risk stratification as treatment target in pulmonary arterial hypertension.

Managing Pulmonary Arterial Hypertension With Cardiopulmonary Comorbidities

Pulmonary arterial hypertension (PAH) and pulmonary hypertension associated with left-sided heart and lung diseases are most commonly easily discriminated and treated accordingly. With the changing epidemiology of PAH, however, a growing proportion of patients at the time of diagnosis present with comorbidities of varying severity. In addition to classical PAH, two distinct phenotypes have emerged: a heart failure with preserved ejection fraction-like phenotype and a lung phenotype. Importantly, the evidence supporting the currently proposed treatment algorithm for PAH has been generated mainly from PAH trials in which patients with cardiopulmonary comorbidities have been underrepresented or excluded. As a consequence, the best therapeutic approach for patients with common PAH with cardiopulmonary comorbidities remains largely unknown and requires further investigation. The present article reviews the relevant literature on the topic and describes the authors' views on the current therapeutic approach for these patients.

Risk Stratification in Pulmonary Arterial Hypertension, Update and Perspectives

Risk stratification in pulmonary arterial hypertension (PAH) is crucial in assessing patient prognosis. It serves a prominent role in everyday patient care and can be determined using several validated risk assessment scores worldwide. The recently published 2022 European Society of Cardiology (ESC)/European Respiratory Society (ERS) guidelines underline the importance of risk stratification not only at baseline but also during follow-up. Achieving a low-risk status has now become the therapeutic goal, emphasising the importance of personalised therapy. The application of these guidelines is also important in determining the timing for lung transplantation referral. In this review, we summarise the most relevant prognostic factors of PAH as well as the parameters used in PAH risk scores and their evolution in the guidelines over the last decade. Finally, we describe the central role that risk stratification plays in the current guidelines not only in European countries but also in Asian countries.

Hemodynamic characteristics in patients with pulmonary hypertension and chronic obstructive pulmonary disease: A retrospective monocentric cohort study

BACKGROUND

Pulmonary hypertension (PH) is a hemodynamic condition characterized by an abnormal elevation in pulmonary arterial pressures. Several pathophysiological pre-capillary and post-capillary mechanisms have been described. PH is a common complication of chronic obstructive pulmonary disease (COPD), however, the prevalence of each mechanism in the development of PH in patients with COPD has been hardly studied.

METHODS

We reported the clinical, functional, hemodynamic characteristics and outcomes of patients diagnosed with COPD and PH among the expert PH center of Nancy between January 1^st, 2015 and March 31^st, 2021.

RESULTS

123 patients with COPD and PH were included. Most patients (n=122, 99%) had a pre-capillary mechanism, 9% (n=11) a post-capillary mechanism, and 1% (n=1) an unclassified mechanism. 111 (90%) patients had pure pre-capillary PH and 11 (9%) patients had combined pre- and post-capillary PH. Combined pre- and post-capillary PH group was characterized by higher prevalence of cardiovascular comorbidities and of sleep apnea-hypopnea syndrome, a higher body mass index, lower lung volumes, higher mean pulmonary arterial pressure, pulmonary arterial wedge pressure and right atrial pressure. At follow-up (median 30 months), 52 patients had died, and 11 had undergone lung transplantation. One-year, three-year and five-year transplant-free survival rates were 71%, 29% and 11% respectively. There was no difference on outcomes between groups.

CONCLUSION

PH in COPD patients is mostly due to pre-capillary mechanism. However, the existence of various and numerous comorbidities in COPD, especially cardiovascular, can lead to the participation of post-capillary mechanisms in the development of PH. Further studies are needed to confirm these findings and to assess the impact on outcomes and management strategies in these different patients.

Oxygenated hemoglobin as prognostic marker among patients with systemic sclerosis screened for pulmonary hypertension

Oxygenated hemoglobin (OxyHem) in arterial blood may reflect disease severity in patients with systemic sclerosis (SSc). The aim of this study was to analyze the predictive value of OxyHem in SSc patients screened for pulmonary hypertension (PH). OxyHem (g/dl) was measured by multiplying the concentration of hemoglobin with fractional oxygen saturation in arterialized capillary blood. Prognostic power was compared with known prognostic parameters in SSc using uni- and multivariable analysis. A total of 280 SSc patients were screened, 267 were included in the analysis. No signs of pulmonary vascular disease were found in 126 patients, while 141 patients presented with mean pulmonary arterial pressure ≥ 21 mmHg. Interstitial lung disease (ILD) was identified in 70 patients. Low OxyHem ≤ 12.5 g/dl at baseline was significantly associated with worse survival (P = 0.046). In the multivariable analysis presence of ILD, age ≥ 60 years and diffusion capacity for carbon monoxide (DLCO) ≤ 65% were negatively associated with survival. The combination of low DLCO and low OxyHem at baseline could predict PH at baseline (sensitivity 76.1%). This study detected for the first time OxyHem ≤ 12.5 g/dl as a prognostic predictor in SSc patients. Further studies are needed to confirm these results.

Gezielte medikamentöse Therapie der pulmonalarteriellen Hypertonie nach den aktuellen Leitlinien

Dieser Artikel stellt die gezielte Therapie der pulmonalarteriellen Hypertonie (PAH) vor. Die medikamentöse Therapie der PAH hat sich in den letzten Jahren entscheidend verbessert und ermöglicht heute vielen Patienten eine deutliche Verbesserung der körperlichen Belastbarkeit, Lebensqualität und des Langzeitüberlebens. Die neuen ESC/ERS-Leitlinien zur pulmonalen Hypertonie haben die aus vielen neuen Studien entstandenen Evidenzen zusammengetragen, bewertet und den therapeutischen Algorithmus und die Therapieempfehlungen entsprechend angepasst. In dem folgenden Artikel werden die neuen Empfehlungen zur medikamentösen Therapie der PAH zusammengefasst und eingeordnet. Die PAH-Therapie wird wie bisher am Schweregrad der Erkrankung orientiert, der bei Diagnose nach einem 3-Risikostufen-Modell abgeschätzt wird. Neu ist die Anwendung eines 4-stufigen Risikomodells bei der Therapieanpassung im Krankheitsverlauf. In den neuen Leitlinien werden erstmals auch Therapieempfehlungen für Patienten mit PAH und Komorbiditäten gegeben.

Pulmonale Hypertonie bei Lungenerkrankungen

Die pulmonale Hypertonie (PH) ist eine häufige Komorbidität von Lungenerkrankungen wie der chronisch obstruktiven Lungenerkrankung oder der idiopathischen pulmonalen Fibrose und geht mit einer erhöhten Letalität einher. Die pulmonalarterielle Hypertonie (PAH) ist hingegen eine seltene Erkrankung, ebenfalls mit hoher Letalität. Durch das häufig ältere und komorbide Patientengut der PAH ergeben sich Subgruppen, die sich hinsichtlich ihres Therapieansprechens und der Letalität von typischen PAH-Patienten unterscheiden. In den letzten Jahren hat sich gezeigt, dass sich neben dem kardialen bzw. Linksherzphänotyp auch ein pulmonaler bzw. kardiopulmonaler Phänotyp abgrenzen lässt. Die Differenzierung zu einer schwergradigen PH bei Lungengrunderkrankung kann schwierig sein und ist aufgrund der unterschiedlichen Therapiestrategien Expertenzentren vorbehalten.

Oxygen Therapy in Pulmonary Vascular Disease: A Systematic Review, Meta-Analysis, and Comment

Main pulmonary vascular diseases (PVD) with precapillary pulmonary hypertension (PH) are pulmonary arterial and chronic thromboembolic PH. Guidelines recommend supplemental oxygen therapy (SOT) for severely hypoxemic patients with PH, but evidence is scarce. The authors performed a systematic review and where possible meta-analyses on the effects of SOT on hemodynamics and exercise performance in patients with PVD. In PVD, short-term SOT significantly improved mean pulmonary artery pressure and exercise performance. There is growing evidence on the benefit of long-term SOT for selected patients with PVD regarding exercise capacity and maybe even survival.

Phenotyping of idiopathic pulmonary arterial hypertension: a registry analysis

BACKGROUND

Among patients meeting diagnostic criteria for idiopathic pulmonary arterial hypertension (IPAH), there is an emerging lung phenotype characterised by a low diffusion capacity for carbon monoxide (DLCO) and a smoking history. The present study aimed at a detailed characterisation of these patients.

METHODS

We analysed data from two European pulmonary hypertension registries, COMPERA (launched in 2007) and ASPIRE (from 2001 onwards), to identify patients diagnosed with IPAH and a lung phenotype defined by a DLCO of less than 45% predicted and a smoking history. We compared patient characteristics, response to therapy, and survival of these patients to patients with classical IPAH (defined by the absence of cardiopulmonary comorbidities and a DLCO of 45% or more predicted) and patients with pulmonary hypertension due to lung disease (group 3 pulmonary hypertension).

FINDINGS

The analysis included 128 (COMPERA) and 185 (ASPIRE) patients with classical IPAH, 268 (COMPERA) and 139 (ASPIRE) patients with IPAH and a lung phenotype, and 910 (COMPERA) and 375 (ASPIRE) patients with pulmonary hypertension due to lung disease. Most patients with IPAH and a lung phenotype had normal or near normal spirometry, a severe reduction in DLCO, with the majority having no or a mild degree of parenchymal lung involvement on chest computed tomography. Patients with IPAH and a lung phenotype (median age, 72 years [IQR 65-78] in COMPERA and 71 years [65-76] in ASPIRE) and patients with group 3 pulmonary hypertension (median age 71 years [65-77] in COMPERA and 69 years [63-74] in ASPIRE) were older than those with classical IPAH (median age, 45 years [32-60] in COMPERA and 52 years [38-64] in ASPIRE; p<0·0001 for IPAH with a lung phenotype vs classical IPAH in both registries). While 99 (77%) patients in COMPERA and 133 (72%) patients in ASPIRE with classical IPAH were female, there was a lower proportion of female patients in the IPAH and a lung phenotype cohort (95 [35%] COMPERA; 75 [54%] ASPIRE), which was similar to group 3 pulmonary hypertension (336 [37%] COMPERA; 148 [39%] ASPIRE]). Response to pulmonary arterial hypertension therapies at first follow-up was available from COMPERA. Improvements in WHO functional class were observed in 54% of patients with classical IPAH, 26% of patients with IPAH with a lung phenotype, and 22% of patients with group 3 pulmonary hypertension (p<0·0001 for classical IPAH vs IPAH and a lung phenotype, and p=0·194 for IPAH and a lung phenotype vs group 3 pulmonary hypertension); median improvements in 6 min walking distance were 63 m, 25 m, and 23 m for these cohorts respectively (p=0·0015 for classical IPAH vs IPAH and a lung phenotype, and p=0·64 for IPAH and a lung phenotype vs group 3 pulmonary hypertension), and median reductions in N-terminal-pro-brain-natriuretic-peptide were 58%, 27%, and 16% respectively (p=0·0043 for classical IPAH vs IPAH and a lung phenotype, and p=0·14 for IPAH and a lung phenotype vs group 3 pulmonary hypertension). In both registries, survival of patients with IPAH and a lung phenotype (1 year, 89% in COMPERA and 79% in ASPIRE; 5 years, 31% in COMPERA and 21% in ASPIRE) and group 3 pulmonary hypertension (1 year, 78% in COMPERA and 64% in ASPIRE; 5 years, 26% in COMPERA and 18% in ASPIRE) was worse than survival of patients with classical IPAH (1 year, 95% in COMPERA and 98% in ASPIRE; 5 years, 84% in COMPERA and 80% in ASPIRE; p<0·0001 for IPAH with a lung phenotype vs classical IPAH in both registries).

INTERPRETATION

A cohort of patients meeting diagnostic criteria for IPAH with a distinct, presumably smoking-related form of pulmonary hypertension accompanied by a low DLCO, resemble patients with pulmonary hypertension due to lung disease rather than classical IPAH. These observations have pathogenetic, diagnostic, and therapeutic implications, which require further exploration.

FUNDING

COMPERA is funded by unrestricted grants from Acceleron, Bayer, GlaxoSmithKline, Janssen, and OMT. The ASPIRE Registry is supported by Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.

Circulating Blood-Based Biomarkers in Pulmonary Hypertension

Pulmonary hypertension (PH) is a serious hemodynamic condition, characterized by increased pulmonary vascular resistance (PVR), leading to right heart failure (HF) and death when not properly treated. The prognosis of PH depends on etiology, hemodynamic and biochemical parameters, as well as on response to specific treatment. Biomarkers appear to be useful noninvasive tools, providing information about the disease severity, treatment response, and prognosis. However, given the complexity of PH, it is impossible for a single biomarker to be adequate for the broad assessment of patients with different types of PH. The search for novel emerging biomarkers is still ongoing, resulting in a few potential biomarkers mirroring numerous pathophysiological courses. In this review, markers related to HF, myocardial remodeling, inflammation, hypoxia and tissue damage, and endothelial and pulmonary smooth muscle cell dysfunction are discussed in terms of diagnosis and prognosis. Extracellular vesicles and other markers with complex backgrounds are also reviewed. In conclusion, although many promising biomarkers have been identified and studied in recent years, there are still insufficient data on the application of multimarker strategies for monitoring and risk stratification in PH patients.