Pulmonary hypertension due to high cardiac output

Pulmonary hypertension (PH) is usually associated with a normal or decreased cardiac output (CO). Less commonly, PH can occur in the context of a hyperdynamic circulation, characterized by high CO (>8 L/min) and/or cardiac index ≥4 L/min/m² in the setting of a decreased systemic vascular resistance. PH due to high CO can occur due to multiple conditions and in general remains understudied. In this review article we describe the pathophysiology, etiology, diagnosis, hemodynamic characteristics, and management of PH in the setting of high CO. It is important to recognize this distinct entity as PH tends to improve with treatment of the underlying etiology and PH specific therapies may worsen the hemodynamic state.

Insights into bone morphogenetic proteins in cardiovascular diseases

Bone morphogenetic proteins (BMPs) are secretory proteins belonging to the transforming growth factor-β (TGF-β) superfamily. These proteins play important roles in embryogenesis, bone morphogenesis, blood vessel remodeling and the development of various organs. In recent years, as research has progressed, BMPs have been found to be closely related to cardiovascular diseases, especially atherosclerosis, vascular calcification, cardiac remodeling, pulmonary arterial hypertension (PAH) and hereditary hemorrhagic telangiectasia (HHT). In this review, we summarized the potential roles and related mechanisms of the BMP family in the cardiovascular system and focused on atherosclerosis and PAH.

Long-term impact of add-on sequential triple combination therapy in pulmonary arterial hypertension: real world experience

BACKGROUND

Sequential triple combination therapy is recommended for pulmonary arterial hypertension (PAH) patients who are not at therapeutic goal on dual therapy, but long-term data on efficacy and safety is scarce.

OBJECTIVE

To assess the long-term impact of sequential triple combination therapy in patients with PAH who are not at goal on dual combination therapy.

STUDY DESIGN AND METHODS

We performed a retrospective observational study in a racially/ethnically diverse cohort of consecutive PAH patients on a stable dual therapy regimen who remained in intermediate- or high-risk category and were subsequently initiated on sequential triple combination therapy. We studied interval change in functional, echocardiographic, and hemodynamic parameters, REVEAL 2.0 risk category and ERS/ESC 2022 simplified four-strata risk category. Multivariate logistic regression analysis was performed to identify independent predictors of successful risk reduction (achievement or maintenance of REVEAL 2.0 low-risk category). Kaplan-Meier survival curves were created to assess the effect of risk reduction on survival.

RESULTS

Out of 414 PAH patients seen in our program, 55 patients received add-on sequential triple combination regimen and had follow-up hemodynamic data. The mean age was 57 years, with 85% women. The most common etiology of PAH was idiopathic/heritable (41.8%). Most patients were WHO functional class III (76.4%), and 34.5% of patients were in high-risk category (REVEAL 2.0). On a median follow-up of 68 weeks, there was a significant improvement in WHO Functional Class (p < 0.001), six-minute walk distance (35 m) with 61.8% of patients achieving low-risk status by REVEAL 2.0, and a 28% of patients' improvement in pulmonary vascular resistance. Female gender was identified as a strong predictor of successful risk reduction, whereas Hispanic ethnicity estimated right atrial pressure on echocardiogram and pericardial effusion predicted lower probability of risk reduction. Patients who achieved or maintained low-risk status had significantly improved survival.

CONCLUSION

Add-on sequential triple combination therapy significantly increased functional, echocardiographic, and hemodynamic parameters with improvement in risk category and survival.

Initial Triple Combination Therapy Including Intravenous Prostaglandin I2 for the Treatment of Patients with Severe Pulmonary Arterial Hypertension

Upfront combination therapy including intravenous prostaglandin I₂ (PGI₂-IV) is recognized as the most appropriate treatment for patients with severe pulmonary arterial hypertension (PAH). This retrospective study aimed to determine reasons why this therapy is not used for some patients with severe PAH and describe the hemodynamic and clinical prognoses of patients receiving initial combination treatment with (PGI₂-IV+) or without (PGI₂-IV-) PGI₂-IV.Data for patients with severe PAH (World Health Organization Functional Class III/IV and mean pulmonary arterial pressure [mPAP] ≥ 40 mmHg) were extracted from the Japan Pulmonary Hypertension Registry. Overall, 73 patients were included (PGI₂-IV + n = 17; PGI₂-IV- n = 56). The PGI₂-IV+ cohort was younger than the PGI₂-IV- cohort (33.8 ± 10.6 versus 52.6 ± 18.2 years) and had higher mPAP (58.1 ± 12.9 versus 51.8 ± 9.0 mmHg), greater prevalence of idiopathic PAH (88% versus 32%), and less prevalence of connective tissue disease-associated PAH (0% versus 29%). Hemodynamic measures, including mPAP, showed improvement in both cohorts (post-treatment median [interquartile range] 38.5 [17.0-40.0] for the PGI₂-IV + cohort and 33.0 [25.0-43.0] mmHg for the PGI₂-IV - cohort). Deaths (8/56) and lung transplantation (1/56) occurred only in the PGI₂-IV - cohort.These Japanese registry data indicate that older age, lower mPAP, and non-idiopathic PAH may influence clinicians against using upfront combination therapy including PGI₂-IV for patients with severe PAH. Early combination therapy including PGI₂-IV was associated with improved hemodynamics from baseline, but interpretation is limited by the small sample size.

Hemodynamic assessment of transitioning from parenteral prostacyclin to selexipag in pediatric pulmonary hypertension

Despite the increase in therapeutic options, parenteral prostacyclins remain the cornerstone in the medical management of pulmonary arterial hypertension (PAH). While the use of parenteral prostacyclins in pediatric patients is well documented, less is known about alternative drug delivery methods such as enteral administration. Given that parenteral routes of prostacyclin administration (IV or SC) are invariably accompanied by complicated logistics and lifestyle compromises, enteral prostacyclin administration represents an attractive treatment option. Selexipag (Uptravi®) was approved for adults PAH in 2015. There is limited data on the hemodynamic efficacy of transitioning from parenteral prostacyclins to selexipag, particularly in the pediatric population. We report 11 pediatric PAH patients who underwent this transition, in which 10 had complete cardiac catheterization data before and following the transition to selexipag. All patients/families reported an improvement in quality of life, and the transitions occurred without adverse effects. However, 3 of the 11 (27%) did not tolerate the transition; two for worsening hemodynamics, and one for acute right ventricular failure in the setting of an intercurrent illness. In addition, the transition to selexipag was associated with a modest increase in pulmonary vascular resistance index (6/10) and decrease in cardiac index (6/10) in some patients. Selexipag use in pediatric PAH represents a significant addition to our therapeutic arsenal, and its use provides a meaningful improvement in quality of life compared with other prostacyclin formulations. However, when goals of care include aggressive disease management, a decision between improved quality of life and possible adverse outcomes must be considered, and its substitution should include cautious, close, long-term follow-up.

Selexipag-based triple combination therapy improves prognosis in Chinese pulmonary arterial hypertension patients

Aim

Selexipag is an oral selective prostacyclin receptor agonist approved for treatment of patients with pulmonary arterial hypertension (PAH). In the present study, we aim to assess the safety and efficacy of selexipag in triple combination therapy with endothelial receptor antagonists (ERAs) and PDE5is for Chinese PAH patients.

Methods and results

A single center retrospective study was performed on group 1 PAH patients (n = 68) initiating triple combination therapy with selexipag from 1 February 2020 to 31 August 2021 in Qilu Hospital of Shandong University (Shandong, China). Adolescents, children, and PAH patients with unrepaired congenital heart disease were excluded. The French pulmonary hypertension network (FPHN) non-invasive risk assessment, echocardiogram parameters, and clinical data, including tolerability, safety, and death/hospitalization events associated with PAH, were collected. Of the 68 patients, 31 (45.6%) patients had tolerable side effects while only a single patient discontinued selexipag due to severe diarrhea. In the analysis of the efficacy set of 62 patients, the median selexipag treatment time from selexipag initiation to last risk assessment was 27 (21, 33) weeks. Compared to baseline parameters, the percentage of WHO FC III/IV decreased from 77.4% (48) to 24.2% (15) (p = 0.000), median 6-min walk distance (6MWD) increased 82 m [from 398 (318, 450) to 480 (420, 506) m; p = 0.000], and NT-proBNP levels decreased from 1,216 (329, 2,159) to 455 (134, 1,678) pg/mL (p = 0.007). Patients who improved to three low-risk criteria increased from 9.7 to 38.7%. Right ventricular diameter (RV) diameter also decreased and was accompanied by an improved tricuspid annular plane systolic excursion (TAPSE). Patients transitioning from subcutaneous treprostinil to selexipag continued to show improvements in WHO FC, 6MWD (404 ± 94 vs. 383 ± 127 m) and NT-proBNP levels (2,319 ± 2,448 vs. 2,987 ± 3,770 pg/mL). Finally, the 1-year event free survival rate was 96.7% for patients initiating the triple combination therapy within 3 years of PAH diagnosis.

Conclusion

Triple combination therapy with selexipag was safe and effective in Chinese PAH patients, which was confirmed by acceptable tolerability, and improved exercise capacity, right heart function, risk assessment, and prognosis.

Pulmonary pressure recovery in idiopathic, hereditary and drug and toxin-induced pulmonary arterial hypertension: Determinants and clinical impact

BACKGROUND

Over the past two decades randomized controlled trials of combination treatments for Pulmonary Arterial Hypertension (PAH) have demonstrated improvements of clinical status but only modest reductions in mean pulmonary pressure (mPAP). Recent experiences with upfront combination treatments including parenteral prostacyclins have shown more substantial mPAP reductions, and have provided grounds for reconsiderations of treatment.

OBJECTIVES

To evaluate the possibility of achieving mPAP <25 mmHg with current treatments, its determinants and the prognostic impact of mPAP reduction.

METHODS

267 consecutive idiopathic, hereditary and drug and toxin-induced PAH patients treated with targeted therapies from three expert centers were followed with periodic clinical and hemodynamic assessments for survival detection.

RESULTS

Fifty-four (20.2%) patients achieved a mPAP <25 mmHg over 58 months (IQR 27-90) of treatment. Determinants of mPAP <25 mmHg were mPAP at diagnosis (HR 0.96, 95C.I. 0.93-0.98, p = 0.002) and an upfront combination strategy (double oral combination: HR 2.3, 95C.I. 1.10-4.76, p = 0.02; one oral plus parenteral prostanoid: HR 3.6, 95C.I. 1.39-9.37, p = 0.008; triple combination employing parenteral prostanoids: HR 12.9, 95C.I. 4.9-33.2, p = 0.0001). Seventy-three patients (27.3%) died. Survival rates were 90%, 79%, 70%, 55%, and 42% at 1, 3, 5, 10, and 15 years, respectively. Mean PAP during follow-up, days from diagnosis to prostanoid initiation and prostanoid maximum dose emerged as independent predictors of survival (Uno-C-index: 0.85). A mPAP ≤35 mmHg during follow-up was identified as the best cutoff value for prediction of survival.

CONCLUSIONS

Reduction to a mean PAP ≤ 35 mmHg appears to be a meaningful treatment target in idiopathic, hereditary and drug and toxin-induced pulmonary arterial hypertension.

Pulmonary Hypertension Definition, Classification, and Epidemiology in Asia

Pulmonary hypertension (PH) is caused by a range of conditions and is important to recognize as it is associated with increased mortality. Pulmonary arterial hypertension refers to a group of PH subtypes affecting the distal pulmonary arteries for which effective treatment is available. The hemodynamic definition of pulmonary arterial hypertension has recently changed which may lead to greater case recognition and earlier treatment. The prevalence of specific PH etiologies may differ depending on geographic region. PH caused by left heart disease is the most common cause of PH worldwide. In Asia, there is greater proportion of congenital heart disease- and connective tissue disease- (especially systemic lupus erythematosus) related PH relative to the West. This review summarizes the definition, classification, and epidemiology of PH as it pertains to Asia.

COMPERA 2.0: a refined four-stratum risk assessment model for pulmonary arterial hypertension

BACKGROUND

Risk stratification plays an essential role in the management of patients with pulmonary arterial hypertension (PAH). The current European guidelines propose a three-stratum model to categorise risk as low, intermediate or high, based on the expected 1-year mortality. However, with this model, most patients are categorised as intermediate risk. We investigated a modified approach based on four risk categories, with intermediate risk subdivided into intermediate-low and intermediate-high risk.

METHODS

We analysed data from the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA), a European pulmonary hypertension registry, and calculated risk at diagnosis and first follow-up based on World Health Organization functional class, 6-min walk distance (6MWD) and serum levels of brain natriuretic peptide (BNP) or N-terminal pro-BNP (NT-proBNP), using refined cut-off values. Survival was assessed using Kaplan-Meier analyses, log-rank testing and Cox proportional hazards models.

RESULTS

Data from 1655 patients with PAH were analysed. Using the three-stratum model, most patients were classified as intermediate risk (76.0% at baseline and 63.9% at first follow-up). The refined four-stratum risk model yielded a more nuanced separation and predicted long-term survival, especially at follow-up assessment. Changes in risk from baseline to follow-up were observed in 31.1% of the patients with the three-stratum model and in 49.2% with the four-stratum model. These changes, including those between the intermediate-low and intermediate-high strata, were associated with changes in long-term mortality risk.

CONCLUSIONS

Modified risk stratification using a four-stratum model based on refined cut-off levels for functional class, 6MWD and BNP/NT-proBNP was more sensitive to prognostically relevant changes in risk than the original three-stratum model.

Dynamics of 6-Minute Walk Distance as a Predictor of Efficiency Specific Pulmonary Vasodilators

Pulmonary hypertension is a severe and often rapidly progressive disease with a fatal outcome. Approved specific therapy with five classes of drugs – prostanoids, endothelin receptor antagonists, phosphodiesterase-5 inhibitors, soluble guanylate cyclase stimulators and prostacyclin receptor agonists has significantly improved the prognosis of patients. An accessible and reproducible criterion of exercise tolerance – a distance walked in six-minute walk test (6MXD) – occupies one of the central places among the performance indicators (clinical, echocardiographic and hemodynamic) of specific pulmonary vasodilators. Reflecting the clinical severity of pulmonary hypertension and, according to some data, its long-term prognosis, the dynamics of 6MXD is an integral component of the combined primary endpoints of randomized controlled trials. In the CHEST-2019 recommendations, the dynamics of the 6MXD was used to standardize the randomized controlled trials. The 6MXD is indispensable for dynamic observation and decisionmaking on further treatment tactics 

Immunosuppressive therapy in patients with connective tissue disease-associated pulmonary arterial hypertension: A systematic review

OBJECTIVES

It is currently accepted that inflammation plays an important role in the pathogenesis of connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH). However, the efficacy of immunosuppressive therapy remains anecdotal. The objective of this systematic review was to evaluate the efficacy of immunosuppressive therapy in patients with CTD-PAH and to further assess whether response differs between CTD subtypes and clinical features.

METHODS

We systematically searched studies reporting the treatment response of immunosuppressants and biological agents in CTD-PAH from PUBMED, EMBASE, the Cochrane Library, and Scopus. Studies had to report treatment regime and response criteria. The risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

Seven independent cohorts, 1 trial, and 1 case-series encompassing 439 patients with CTD-PAH were included. Patients were divided into 2 groups according to the therapeutic regimen. There were 146 patients in the immunosuppressants group with better heart function at baseline and 52.1% (76/146) of them were responders. There were 236 patients treated with immunosuppressants combined with PAH-specific therapy who showed more severity at baseline and 41.1% (97/236) of them were responders. Among different CTD subtypes, patients with systemic lupus erythematosus-associated PAH (SLE-PAH) showed a better response to immunosuppressants (response rate 48.1%). What is more, 1 randomized controlled trial showed the potential therapeutic value of rituximab (n = 57) in CTD-PAH patients.

CONCLUSIONS

Current studies support the use of immunosuppressive therapy in CTD-PAH, especially in SLE-PAH. Further studies on biological agents and the therapeutic effect of different immunosuppressants are still needed.

Prognostic impact of follow-up pulmonary vascular resistance in pulmonary arterial hypertension

Objective

Pulmonary arterial hypertension (PAH), caused by pulmonary artery remodelling and increased pulmonary vascular resistance (PVR) due to an unknown mechanism, is an intractable disease with a poor prognosis. The recent development of PAH-specific treatment medications may allow for higher PVR reduction than previously achieved. This study aimed to identify the prognostic significance of follow-up PVR levels achieved shortly after the initiation of targeted treatment in patients with idiopathic/heritable pulmonary arterial hypertension (I/H-PAH).

Methods

We analysed the data of all patients with I/H-PAH admitted to our hospital between 1998 and 2019. We collected data at baseline and during the first invasive haemodynamic evaluation. The primary outcome was death or lung transplantation.

Results

Of the 133 treatment-naïve patients enrolled in this study, 47 experienced adverse events during a median follow-up period of 6.4 (IQR 3.5–11.5) years. The median time interval to first follow-up from diagnosis was 162 (IQR 117–253) days. Incidence of the primary outcome was significantly lower in patients who achieved low PVR at follow-up. Of risk factors evaluated at follow-up, the multivariate Cox regression analysis revealed PVR as an independent predictor of the primary outcome (HR 1.103, 95% CI 1.029 to 1.183; p=0.006). The results were consistent across risk profiles according to the simplified risk stratification recommended by the European Society of Cardiology and European Respiratory Society guidelines.

Conclusion

Follow-up PVR was an independent predictor of transplant-free survival in patients with I/H-PAH. Evaluation of haemodynamic status shortly after initiating treatment may help predict long-term prognosis.

Temporal trends in pulmonary arterial hypertension: results from the COMPERA registry

BACKGROUND

Since 2015, the European pulmonary hypertension guidelines recommend the use of combination therapy in most patients with pulmonary arterial hypertension (PAH). However, it is unclear to what extent this treatment strategy is adopted in clinical practice and if it is associated with improved long-term survival.

METHODS

We analysed data from COMPERA, a large European pulmonary hypertension registry, to assess temporal trends in the use of combination therapy and survival of patients with newly diagnosed PAH between 2010 and 2019. For survival analyses, we looked at annualised data and at cumulated data comparing the periods 2010-2014 and 2015-2019.

RESULTS

A total of 2531 patients were included. The use of early combination therapy (within 3 months after diagnosis) increased from 10.0% in patients diagnosed with PAH in 2010 to 25.0% in patients diagnosed with PAH in 2019. The proportion of patients receiving combination therapy 1 year after diagnosis increased from 27.7% to 46.3%. When comparing the 2010-2014 and 2015-2019 periods, 1-year survival estimates were similar (89.0% (95% CI 87.2-90.9%) and 90.8% (95% CI 89.3-92.4%), respectively), whereas there was a slight but nonsignificant improvement in 3-year survival estimates (67.8% (95% CI 65.0-70.8%) and 70.5% (95% CI 67.8-73.4%), respectively).

CONCLUSIONS

The use of combination therapy increased from 2010 to 2019, but most patients still received monotherapy. Survival rates at 1 year after diagnosis did not change over time. Future studies need to determine if the observed trend suggesting improved 3-year survival rates can be confirmed.

Mechanisms of pulmonary vascular dysfunction in pulmonary hypertension and implications for novel therapies

Pulmonary hypertension (PH) is a serious disease characterized by various degrees of pulmonary vasoconstriction and progressive fibroproliferative remodeling and inflammation of the pulmonary arterioles that lead to increased pulmonary vascular resistance, right ventricular hypertrophy, and failure. Pulmonary vascular tone is regulated by a balance between vasoconstrictor and vasodilator mediators, and a shift in this balance to vasoconstriction is an important component of PH pathology, Therefore, the mainstay of current pharmacological therapies centers on pulmonary vasodilation methodologies that either enhance vasodilator mechanisms such as the NO-cGMP and prostacyclin-cAMP pathways and/or inhibit vasoconstrictor mechanisms such as the endothelin-1, cytosolic Ca2+, and Rho-kinase pathways. However, in addition to the increased vascular tone, many patients have a "fixed" component in their disease that involves altered biology of various cells in the pulmonary vascular wall, excessive pulmonary artery remodeling, and perivascular fibrosis and inflammation. Pulmonary arterial smooth muscle cell (PASMC) phenotypic switch from a contractile to a synthetic and proliferative phenotype is an important factor in pulmonary artery remodeling. Although current vasodilator therapies also have some antiproliferative effects on PASMCs, they are not universally successful in halting PH progression and increasing survival. Mild acidification and other novel approaches that aim to reverse the resident pulmonary vascular pathology and structural remodeling and restore a contractile PASMC phenotype could ameliorate vascular remodeling and enhance the responsiveness of PH to vasodilator therapies.

Mortality in Pulmonary Arterial Hypertension in the Modern Era: Early Insights From the Pulmonary Hypertension Association Registry

Background Current mortality data for pulmonary arterial hypertension (PAH) in the United States are based on registries that enrolled patients prior to 2010. We sought to determine mortality in PAH in the modern era using the PHAR (Pulmonary Hypertension Association Registry). Methods and Results We identified all adult patients with PAH enrolled in the PHAR between September 2015 and September 2020 (N=935). We used Kaplan-Meier survival analysis and Cox proportional hazards models to assess mortality at 1, 2, and 3 years. Patients were stratified based on disease severity by 3 validated risk scores. In treatment-naïve patients, we compared survival based on initial treatment strategy. The median age was 56 years (44-68 years), and 76% were women. Of the 935 patients, 483 (52%) were ≤6 months from PAH diagnosis. There were 121 deaths (12.9%) during a median follow-up time of 489 days (281-812 days). The 1-, 2-, and 3-year mortality was 8% (95% CI, 6%-10%), 16% (95% CI, 13%-19%), and 21% (95% CI, 17%-25%), respectively. When stratified into low-, intermediate-, and high-risk PAH, the mortality at 1, 2, and 3 years was 1%, 4% to 6%, and 7% to 11% for low risk; 7% to 8%, 11% to 16%, and 18% to 20% for intermediate risk; and 12% to 19%, 22% to 38%, and 28% to 55% for high risk, respectively. In treatment-naïve patients, initial combination therapy was associated with better 1-year survival (adjusted hazard ratio, 0.43 [95% CI, 0.19-0.95]; P=0.037). Conclusions Mortality in the intermediate- and high-risk patients with PAH remains unacceptably high in the PHAR, suggesting the importance for early diagnosis, aggressive use of available therapies, and the need for better therapeutics.

Diagnosis and Treatment of Pulmonary Arterial Hypertension: A Review

IMPORTANCE

Pulmonary arterial hypertension (PAH) is a subtype of pulmonary hypertension (PH), characterized by pulmonary arterial remodeling. The prevalence of PAH is approximately 10.6 cases per 1 million adults in the US. Untreated, PAH progresses to right heart failure and death.

OBSERVATIONS

Pulmonary hypertension is defined by a mean pulmonary artery pressure greater than 20 mm Hg and is classified into 5 clinical groups based on etiology, pathophysiology, and treatment. Pulmonary arterial hypertension is 1 of the 5 groups of PH and is hemodynamically defined by right heart catheterization demonstrating a mean pulmonary artery pressure greater than 20 mm Hg, a pulmonary artery wedge pressure of 15 mm Hg or lower, and a pulmonary vascular resistance of 3 Wood units or greater. Pulmonary arterial hypertension is further divided into subgroups based on underlying etiology, consisting of idiopathic PAH, heritable PAH, drug- and toxin-associated PAH, pulmonary veno-occlusive disease, PAH in long-term responders to calcium channel blockers, and persistent PH of the newborn, as well as PAH associated with other medical conditions including connective tissue disease, HIV, and congenital heart disease. Early presenting symptoms are nonspecific and typically consist of dyspnea on exertion and fatigue. Currently approved therapy for PAH consists of drugs that enhance the nitric oxide-cyclic guanosine monophosphate biological pathway (sildenafil, tadalafil, or riociguat), prostacyclin pathway agonists (epoprostenol or treprostinil), and endothelin pathway antagonists (bosentan and ambrisentan). With these PAH-specific therapies, 5-year survival has improved from 34% in 1991 to more than 60% in 2015. Current treatment consists of combination drug therapy that targets more than 1 biological pathway, such as the nitric oxide-cyclic guanosine monophosphate and endothelin pathways (eg, ambrisentan and tadalafil), and has shown demonstrable improvement in morbidity and mortality compared with the previous conventional single-pathway targeted monotherapy.

CONCLUSIONS AND RELEVANCE

Pulmonary arterial hypertension affects an estimated 10.6 per 1 million adults in the US and, without treatment, typically progresses to right heart failure and death. First-line therapy with drug combinations that target multiple biological pathways are associated with improved survival.

Aggressive Afterload Lowering to Improve the Right Ventricle: A New Target for Medical Therapy in Pulmonary Arterial Hypertension?

Despite numerous therapeutic advances in pulmonary arterial hypertension, patients continue to suffer high morbidity and mortality, particularly considering a median age of 50 years. This article explores whether early, robust reduction of right ventricular afterload would facilitate substantial improvement in right ventricular function and thus whether afterload reduction should be a treatment goal for pulmonary arterial hypertension. The earliest clinical studies of prostanoid treatment in pulmonary arterial hypertension demonstrated an important link between lowering mean pulmonary arterial pressure (or pulmonary vascular resistance) and improved survival. Subsequent studies of oral monotherapy or sequential combination therapy demonstrated smaller reductions in mean pulmonary arterial pressure and pulmonary vascular resistance. More recently, retrospective reports of initial aggressive prostanoid treatment or initial combination oral and parenteral therapy have shown marked afterload reduction along with significant improvements in right ventricular function. Some data suggest that reaching threshold levels for pressure or resistance (components of right ventricular afterload) may be key to interrupting the self-perpetuating injury of pulmonary vascular disease in pulmonary arterial hypertension and could translate into improved long-term clinical outcomes. Based on these clues, the authors postulate that improved clinical outcomes might be achieved by targeting significant afterload reduction with initial oral combination therapy and early parenteral prostanoids.

Carbon Monoxide Diffusion Capacity as a Severity Marker in Pulmonary Hypertension

Carbon monoxide diffusion capacity (DLCO) is negatively associated with patient survival in idiopathic pulmonary hypertension (PH), but is not included in the risk stratification score proposed by the 2015 European guidelines. Since 2015, several new stratification scores based on a 3- or 4-severity scale have been explored. This retrospective cohort single-center study sought to investigate the association between DLCO and PH severity and survival. We included 85 treatment-naive patients with precapillary PH and DLCO measurement at diagnosis. DLCO status, based on lower and upper quartiles ranges, was added to a 3- and a 4-strata modified-risk assessment. DLCO was strongly associated with transplant-free survival (HR 0.939, 95% CI: 0.908–0.971, p < 0.001). In the intermediate and high-risk categories, DLCO was associated with transplant-free survival, irrespective of the risk category (HR 0.934, 95% CI: 0.880–0.980, p = 0.005). The correlation between modified-risk category and transplant-free survival was significant (HR 4.60, 95% CI: 1.294–16.352, p = 0.018). Based on the Akaike information criterion (AIC) levels, the 3- and 4-strata modified-risk stratification fits our results better than the conventional stratification. Low DLCO is associated with patient transplant-free survival, independently of the risk category. Inclusion of DLCO into a PH risk stratification score seems promising and needs further investigation.

COMPERA 2.0: A refined 4-strata risk assessment model for pulmonary arterial hypertension

Background

Risk stratification plays an essential role in the management of patients with pulmonary arterial hypertension (PAH). The current European guidelines propose a three-stratum model to categorise risk as low, intermediate or high, based on the expected 1-year mortality. However, with this model, most patients are categorised as intermediate risk. We investigated a modified approach based on four risk categories, with intermediate risk subdivided into intermediate-low and intermediate-high risk.

Methods

We analysed data from the Comparative, Prospective Registry of Newly Initiated Therapies for Pulmonary Hypertension (COMPERA), a European pulmonary hypertension registry, and calculated risk at diagnosis and first follow-up based on World Health Organization functional class, 6-min walk distance (6MWD) and serum levels of brain natriuretic peptide (BNP) or N-terminal pro-BNP (NT-proBNP), using refined cut-off values. Survival was assessed using Kaplan–Meier analyses, log-rank testing and Cox proportional hazards models.

Results

Data from 1655 patients with PAH were analysed. Using the three-stratum model, most patients were classified as intermediate risk (76.0% at baseline and 63.9% at first follow-up). The refined four-stratum risk model yielded a more nuanced separation and predicted long-term survival, especially at follow-up assessment. Changes in risk from baseline to follow-up were observed in 31.1% of the patients with the three-stratum model and in 49.2% with the four-stratum model. These changes, including those between the intermediate-low and intermediate-high strata, were associated with changes in long-term mortality risk.

Conclusions

Modified risk stratification using a four-stratum model based on refined cut-off levels for functional class, 6MWD and BNP/NT-proBNP was more sensitive to prognostically relevant changes in risk than the original three-stratum model.

COMPERA 2.0, a four-stratum risk assessment model based on refined cut-off levels for functional class, 6MWD and BNP/NT-proBNP was more sensitive to prognostically significant changes in risk than the original three-stratum modelhttps://bit.ly/3mzPKjA

Mortality trends in pulmonary arterial hypertension in canada: a temporal analysis of survival per ESC/ERS Guideline Era

INTRODUCTION

The evolution in pulmonary arterial hypertension (PAH) management has been summarized in three iterations of the European Society of Cardiology/European Respiratory Society (ESC/ERS) guidelines. No study has assessed whether changes in management, as reflected in the changing guidelines, has translated to improved long-term survival in PAH.

METHODS

Mixed retrospective/prospective analysis of treatment naïve, incident PAH patients (n=392) diagnosed at three major centers in Canada from 2009-2021. Patients were divided into two groups based on their diagnosis date and in accordance with three ESC/ERS guideline iterations: 2009 and 2015. Overall survival was assessed based on date of diagnosis and initial treatment strategy (i.e. mono versus combination).

RESULTS

In Canada, there was a shift towards more aggressive upfront management with combination therapy after the publication of the 2015 guidelines (10.4% and 30.8% in 2009-2015 patients, and 36.0% and 57.4% in 2016-2021 patients, for baseline and 2-year follow-up respectively). A key factor associated with combination therapy after 2015 was higher pulmonary vascular resistance (p=0.009). The 1, 3 and 5 year survival rates in Canada were 89.2%, 75.6%. and 56.0%, respectively. Despite changes in management, there was no improvement in long-term survival before and after publication of the 2015 ESC/ERS guideline (p=0.53).

CONCLUSIONS

There was an increase in the use of initial and sequential combination therapy in Canada after publication of the 2015 ESC/ERS guidelines, which was not associated with improved long-term survival. These data highlight the continued difficulties of managing this aggressive pulmonary disease in an era without a cure.