Influence of various therapeutic strategies on right ventricular morphology, function and hemodynamics in pulmonary arterial hypertension

Contribution of pressure and flow changes to resistance reduction after pulmonary arterial hypertension treatment: a meta-analysis of 3898 patients

Background

Pulmonary arterial hypertension (PAH)-targeted therapies exert significant haemodynamic changes; however, systematic synthesis is currently lacking.

Methods

We searched PubMed, CENTRAL and Web of Science for studies evaluating mean pulmonary artery pressure (mPAP), cardiac index/cardiac output (CI/CO) and pulmonary vascular resistance (PVR) of PAH-targeted therapies either in monotherapy or combinations as assessed by right heart catheterisation in treatment-naïve PAH patients. We performed a random-effects meta-analysis with meta-regression.

Results

We included 68 studies (90 treatment groups) with 3898 patients (age 47.4±13.2 years, 74% women). In studies with small PVR reduction (<4 WU), CI/CO increase (R2=62%) and not mPAP reduction (R2=24%) was decisive for the PVR reduction (p<0.001 and p=0.36, respectively, in the multivariable meta-regression model); however, in studies with large PVR reduction (>4 WU), both CI/CO increase (R2=72%) and mPAP reduction (R2=35%) contributed significantly to the PVR reduction (p<0.001 and p=0.01, respectively). PVR reduction as a percentage of the pre-treatment value was more pronounced in the oral+prostanoid intravenous/subcutaneous combination therapy (mean difference -50.0%, 95% CI -60.8- -39.2%), compared to oral combination therapy (-41.7%, -47.6- -35.8%), prostanoid i.v./s.c. monotherapy (-31.8%, -37.6- -25.9%) and oral monotherapy (-21.6%, -25.4- -17.8%). Changes in haemodynamic parameters were significantly associated with changes in functional capacity of patients with PAH as expressed by the 6-min walking distance.

Conclusion

Combination therapies, especially with the inclusion of parenteral prostanoids, lead to remarkable haemodynamic improvement in treatment-naïve PAH patients and may unmask the contribution of mPAP reduction to the overall PVR reduction in addition to the increase in CO.

Restoration of right ventricular function in the treatment of pulmonary arterial hypertension

OBJECTIVE

A 45% threshold of right ventricular ejection fraction (RVEF) is proposed clinically relevant in patients with pulmonary arterial hypertension (PAH). We aim to determine treatment response, long-term right ventricular (RV) functional stability and prognosis of patients with PAH reaching or maintaining the RVEF 45% threshold.

METHODS

Incident, treatment-naive, adult PAH patients with cardiac magnetic resonance imaging at baseline and first follow-up were included (total N=127) and followed until date of censoring or death/lung transplantation. Patients were categorised into two groups based on 45% RVEF. Baseline predictors, treatment response and prognosis were assessed with logistic regression analyses, two-way analysis of variance and log-rank tests.

RESULTS

Patients were 50±17 years old, 73% female, of which N=75 reached or maintained the 45% RVEF threshold at follow-up (RVEF≥45%@FU), while N=52 patients did not (RVEF<45%@FU). RV end-diastolic volume and N-terminal pro-B-type natriuretic peptide at baseline were multivariable predictors of an RVEF ≥45% at follow-up. A 40% pulmonary vascular resistance (PVR) reduction resulted in greater improvement in RV function (ΔRVEF 17±11 vs. 5±8; pinteraction<0.001) compared to a PVR reduction <40%, but did not guarantee an RVEF ≥45%. Finally, the 45% RVEF threshold was associated with stable RV function during long-term follow-up and better survival (HR: 1.91 (95% CI: 1.11 to 3.27)). Patients failing to reach or maintain the 45% RVEF threshold at first follow-up mostly stayed below this threshold over the next consecutive visits.

CONCLUSION

After treatment initiation, 60% of patients with PAH reach or maintain the 45% RVEF threshold, which is associated with a long-term stable RV function and favourable prognosis.

Impact of Parenteral Prostanoids in Pulmonary Arterial Hypertension: The Relevance of Timing

Parenteral prostanoids are being recommended in pulmonary arterial hypertension (PAH) treatment, but the prognostic relevance of delayed treatment initiation is still debated. This study assessed the impact of the timing of prostacyclin treatment initiation on reducing PVR and achieving a low-risk profile in PAH patients. The study enrolled 151 patients who started on parenteral prostanoids with different treatment strategies. All patients underwent right heart catheterization, clinical evaluation, and risk assessments at baseline and after 1-year follow-up. Patients with an upfront strategy including parenteral prostanoid plus one oral drug had -5.3 ± 6.2 WU (-50 ± 19%) reduction in PVR, patients with an upfront strategy including parenteral prostanoid plus double oral drug had -12.8 ± 5.9 WU (-68 ± 17%) reduction in PVR, while patients with an add-on strategy including parenteral prostanoid after oral drugs had -3.9 ± 3.5 WU (-23 ± 19%) reduction in PVR. An upfront strategy including parenteral prostanoids was independently associated with an increased likelihood of achieving the greater reduction of PVR compared with an add-on strategy. Additionally, the greater the severity of PH at the time of diagnosis, in terms of PVR and RV reverse remodeling, the higher the probability of treatment failure. An upfront strategy including a parenteral prostanoid is associated with the highest likelihood of achieving a low-risk profile and a greater reduction of PVR compared with parenteral prostanoid as an add-on to oral treatment.

Pathophysiology of the right ventricle in health and disease: an update

The contribution of the right ventricle (RV) to cardiac output is negligible in normal resting conditions when pressures in the pulmonary circulation are low. However, the RV becomes relevant in healthy subjects during exercise and definitely so in patients with increased pulmonary artery pressures both at rest and during exercise. The adaptation of RV function to loading rests basically on an increased contractility. This is assessed by RV end-systolic elastance (Ees) to match afterload assessed by arterial elastance (Ea). The system has reserve as the Ees/Ea ratio or its imaging surrogate ejection fraction has to decrease by more than half, before the RV undergoes an increase in dimensions with eventual increase in filling pressures and systemic congestion. RV-arterial uncoupling is accompanied by an increase in diastolic elastance. Measurements of RV systolic function but also of diastolic function predict outcome in any cause pulmonary hypertension and heart failure with or without preserved left ventricular ejection fraction. Pathobiological changes in the overloaded RV include a combination of myocardial fibre hypertrophy, fibrosis and capillary rarefaction, a titin phosphorylation-related displacement of myofibril tension-length relationships to higher pressures, a metabolic shift from mitochondrial free fatty acid oxidation to cytoplasmic glycolysis, toxic lipid accumulation, and activation of apoptotic and inflammatory signalling pathways. Treatment of RV failure rests on the relief of excessive loading.

Medical Management of Right Ventricular Dysfunction in Pulmonary Arterial Hypertension

PURPOSE OF REVIEW

The purpose of this review is to overview the most relevant and recent knowledge regarding medical management in pulmonary arterial hypertension (PAH).

RECENT FINDINGS

Evidence has shown that PAH patients' quality of life and prognosis depend on the capability of the RV to adapt to increased afterload and to fully recover in response to substantially reduced pulmonary vascular resistance obtained with medical therapy. Data from recent clinical studies show that more aggressive treatment strategies, especially in higher risk categories, determine larger afterload reductions, consequentially increasing the probability of achieving right heart reverse remodeling, therefore improving the patients' survival and quality of life. Remarkable progress has been observed over the past decades in the medical treatment of PAH, related to the development of drugs that target multiple biological pathways, strategies for earlier and more aggressive treatment interventions. New hopes for treatment of patients who are unable to achieve low-risk status have been derived from the phase 2 trial PULSAR and the phase 3 trial STELLAR, which show improvement in the hemodynamic status of patients treated with sotatercept on top of background therapy. Promising results are expected from several ongoing clinical trials targeting new pathways involved in the pathophysiology of PAH.

Riociguat and the right ventricle in pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are progressive diseases that can lead to right heart failure and death. Right ventricular dysfunction, hypertrophy and maladaptive remodelling are consequences of increased right ventricular (RV) afterload in PAH and CTEPH and are indicative of long-term outcomes. Because RV failure is the main cause of morbidity and mortality in PAH and CTEPH, successful treatments should lead to improvements in RV parameters. Riociguat is a soluble guanylate cyclase stimulator approved for the treatment of PAH and inoperable or persistent/recurrent CTEPH after pulmonary endarterectomy. This review examines the current evidence showing the effect of riociguat on the right ventricle, with particular focus on remodelling, function and structural parameters in preclinical models and patients with PAH or CTEPH.

Pulmonary artery pressure-directed therapies in pulmonary arterial hypertension?

Pulmonary arterial hypertension is a rare dyspnea-fatigue syndrome defined by an increase in mean pulmonary artery pressure above 20 mmHg combined with an increase in pulmonary vascular resistance higher than 2 Wood units. The condition is of poor prognosis and still incurable in spite of progress achieved in recent decades. The approach is currently optimized by multi-drug combinations titrated on serial risk assessments using recently validated scores. In this issue of Vascular Pharmacology argument is made based on retrospective registry data from three reference centers in favor of initial multi-drug therapies including a parenteral prostanoid dosed to decrease mPAP to normal. This objective was achieved in only a minority of patients, but improved outcome was demonstrated when mPAP can be brought to below 35 mmHg. This data suggest that pulmonary artery pressure-directed multi-drug therapies in PAH may reverse right heart remodeling and limit progression, or even reverse pulmonary vascular disease. However, further studies are needed to validate mPAP as a primary endpoint in PAH drug trials. In the meantime, aggressive initial prescription of parenteral prostanoids combined with one or two oral drugs targeting the pulmonary circulation under careful clinical, imaging and hemodynamic follow-up may be the best therapeutic strategy.

Real-world evidence of subcutaneous treprostinil use in pulmonary arterial hypertension in Argentina

INTRODUCTION

Pulmonary arterial hypertension is a progressive haemodynamic disease with high morbidity and mortality. Of the different treatments available, the prostacyclin analogues are the drugs of choice for high-risk patients, with treprostinil being the most commonly used drug in Argentina.

METHODOLOGY

The objective of this study is to perform a retrospective evaluation of the efficacy and safety of subcutaneous treprostinil in regular clinical practice in Argentina in 51 patients with pulmonary arterial hypertension after 12 months of follow-up.

RESULTS

The results showed that treatment with subcutaneous treprostinil is associated with a significant improvement in different clinical efficacy parameters: 65% reduction in advanced functional class (p < 0.0001), 130-m increase in the 6-min walk test (p < 0.0001), 65% reduction in the pro B-type natriuretic peptide value (-531 pg/dL; p < 0.0001), significant reduction of 15.7% in pulmonary vascular resistance [-1.3 wood units (WU); p < 0.0001], improved cardiac index with an increase of 16.7% (+0.4 L/min/m²; p = 0.002), as well as a high survival rate (92%) and a 44% incidence of combined events (mortality, heart failure, syncope and/or lung transplantation), without a significant increase in previously reported adverse events. The risk stratification evaluation according to ESC/ERS guidelines showed a significant decrease in the proportion of patients at high risk after the treatment period (p = 0.004).

CONCLUSIONS

These real-world results corroborate the efficacy and safety of subcutaneous treprostinil, even at high doses, and open up the possibility of improving its current use in clinical practice as a first-line therapy, especially in high-risk patient profiles.

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.

Telehealth: A winning weapon to face the COVID-19 outbreak for patients with pulmonary arterial hypertension

Background

COVID-19 pandemic severely affected national health systems, altering the modality and the type of care of patients with acute and chronic diseases. To minimize the risk of exposure to SARS-CoV2 for patients and health professionals, face-to-face visits were cancelled or postponed and the use of telemedicine was strongly encouraged. This reorganization involved especially patients with rare diseases needing periodic comprehensive assessment, such as pulmonary arterial hypertension (PAH).

Main body

The paper reports a proposal of strategy adopted for patients followed at our PAH center in Rome, where patients management was diversified based on clinical risk according to the European Society of Cardiology/European Respiratory Society PH guidelines-derived score and the REVEAL 2.0 score. A close monitoring and support of these patients were made possible by policy changes reducing barriers to telehealth access and promoting the use of telemedicine. Synchronous/asynchronous modalities and remote monitoring were used to collect and transfer medical data in order to guide physicians in therapeutic-decision making. Conversely, the use of implantable monitors providing hemodynamic information and echocardiography-mobile devices wirelessly connecting was limited by the poor experience existing in this setting. Large surveys and clinical trials are welcome to test the potential benefit of the optimal balance between traditional PAH management and telemedicine opportunities.

Conclusion

Italy was found unprepared to manage the dramatic effects caused by COVID-19 on healthcare systems. In this emergency situation telemedicine represented a promising tool especially in rare diseases as PAH, but was limited by its scattered availability and legal and ethical issues. Cohesive partnership of health care providers with regional public health officials is needed to prioritize PAH patients for telemedicine by dedicated tools.

Comment on Topyła-Putowska et al. Echocardiography in Pulmonary Arterial Hypertension: Comprehensive Evaluation and Technical Considerations. J. Clin. Med. 2021, 10, 3229

A comprehensive PAH echocardiographic examination of patients with pulmonary arterial hypertension (PAH) should include a set of parameters resembling the pathophysiological changes occurring in the course of the disease. This approach could help clinicians build a complete picture of the patient, test the effects of targeted therapies and identify patients who need a more aggressive therapeutic approach to achieve a low risk-status.

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.

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.

Oral treprostinil improves pulmonary vascular compliance in pulmonary arterial hypertension

Oral treprostinil has been shown to improve exercise capacity and delay disease progression in patients with pulmonary arterial hypertension (PAH), but its effects on hemodynamics are not well-characterized. The FREEDOM-EV trial was a Phase III, international, placebo-controlled, double-blind, event-driven study in 690 participants with PAH who were taking a single oral PAH therapy. FREEDOM-EV demonstrated a significantly reduced risk for clinical worsening with oral treprostinil taken three times daily and did not uncover new safety signals in PAH patients. Sixty-one participants in the FREEDOM-EV trial volunteered for a hemodynamics sub-study. Pulmonary artery compliance (PAC), a ratio of stroke volume to pulmonary pulse pressure, significantly increased from Baseline to Week 24 in the oral treprostinil group compared with the placebo group (geometric mean 26.4% active vs. -6.0% placebo; ANCOVA p=0.007). There was a significant increase in cardiac output in the oral treprostinil group compared to the placebo group (geometric mean 11.3% active vs. -6.4% placebo; ANCOVA p=0.005) and a corresponding significant reduction in pulmonary vascular resistance (PVR) (geometric mean -21.5 active vs. -1.8% placebo; ANCOVA p=0.02) from Baseline to Week 24. These data suggest that increased compliance contributes to the physiological mechanism by which oral treprostinil improves exercise capacity and delays clinical worsening for patients with PAH.

Computational Simulator Models and Invasive Hemodynamic Monitoring as Tools for Precision Medicine in Pulmonary Arterial Hypertension

Precision medicine, providing the right therapeutic strategy for the right patient, could revolutionize management and prognosis of patients affected by cardiovascular diseases. Big data and artificial intelligence are pivotal for the realization of this ambitious design. In the setting of pulmonary arterial hypertension (PAH), the use of computational models and data derived from ambulatory implantable hemodynamic monitors could provide useful information for tailored treatment, as requested by precision medicine.

The physiologic basis of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare dyspnea-fatigue syndrome caused by a progressive increase in pulmonary vascular resistance (PVR) and eventual right ventricular (RV) failure. In spite of extensive pulmonary vascular remodeling, lung function in PAH is generally well preserved, with hyperventilation and increased physiologic dead space, but minimal changes in lung mechanics and only mild to moderate hypoxemia and hypocapnia. Hypoxemia is mainly caused by a low mixed venous PO₂ from a decreased cardiac output. Hypocapnia is mainly caused by an increased chemosensitivity. Exercise limitation in PAH is cardiovascular rather than ventilatory or muscular. The extent of pulmonary vascular disease in PAH is defined by multipoint pulmonary vascular pressure-flow relationships with a correction for hematocrit. Pulsatile pulmonary vascular pressure-flow relationships in PAH allow for the assessment of RV hydraulic load. This analysis is possible either in the frequency-domain or in the time-domain. The RV in PAH adapts to increased afterload by an increased contractility to preserve its coupling to the pulmonary circulation. When this homeometric mechanism is exhausted, the RV dilates to preserve flow output by an additional heterometric mechanism. Right heart failure is then diagnosed by imaging of increased right heart dimensions and clinical systemic congestion signs and symptoms. The coupling of the RV to the pulmonary circulation is assessed by the ratio of end-systolic to arterial elastances, but these measurements are difficult. Simplified estimates of RV-PA coupling can be obtained by magnetic resonance or echocardiographic imaging of ejection fraction.

The Right Ventricular-Pulmonary Arterial Coupling and Diastolic Function Response to Therapy in Pulmonary Arterial Hypertension

BACKGROUND

Multiparametric risk assessment is used in pulmonary arterial hypertension (PAH) to target therapy. However, this strategy is imperfect as most patients remain in intermediate or high risk after initial treatment with low risk being the goal. Metrics of right ventricular (RV) adaptation are promising tools that may help refine our therapeutic strategy.

RESEARCH QUESTION

Does RV adaptation predict therapeutic response over time?

STUDY DESIGN AND METHODS

We evaluated 52 incident treatment naïve patients with advanced PAH by catheterization and cardiac imaging longitudinally at baseline, follow-up 1 (∼3 mo.) and follow-up 2 (∼18 mo.). All patients were placed on goal-directed therapy with parenteral treprostinil and/or combination therapy with treatment escalation if functional class I-II was not achieved. Therapeutic response was evaluated at follow-up 1 as non-responders (died) or responders and again at follow-up 2 as super-responders (low risk) or partial-responders (high/intermediate risk). Multiparametric risk was based on a simplified ERS/ESC guideline score. RV adaptation was evaluated with the single-beat coupling ratio (Ees/Ea) and diastolic function with diastolic elastance (Eed). Data are expressed as mean±SD or odds ratio [95%CI].

RESULTS

Nine patients (17%) were non-responders. PAH-directed therapy improved ERS low risk from 1 (2%) at baseline to 23 (55%) at follow-up 2. Ees/Ea at presentation was non-significantly higher in responders (0.9±0.4) versus non-responders (0.6±0.4, p=0.09) but was unable to predict super-responder status at follow-up 2 (odds ratio 1.40 [0.28-7.0], p=0.84). Baseline RVEF and change in Eed successfully predicted super-responder status at follow-up 2 (odds ratio 1.15 [1.0-1.27], p=0.009 and 0.29 [0.86-0.96], p=0.04, respectively).

INTERPRETATION

In patients with advanced PAH, RV-PA coupling could not discriminate irreversible RV failure (non-responders) at presentation but showed a late trend to improvement by follow-up 2. Early change in Eed and baseline RVEF were the best predictors of therapeutic response.

Effect of riociguat on right ventricular function in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

BACKGROUND

In the Phase III PATENT-1 (NCT00810693) and CHEST-1 (NCT00855465) studies, riociguat demonstrated efficacy vs placebo in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH). Clinical effects were maintained at 2 years in the long-term extension studies PATENT-2 (NCT00863681) and CHEST-2 (NCT00910429).

METHODS

This post hoc analysis of hemodynamic data from PATENT-1 and CHEST-1 assessed whether riociguat improved right ventricular (RV) function parameters including stroke volume index (SVI), stroke volume, RV work index, and cardiac efficiency. REVEAL Risk Score (RRS) was calculated for patients stratified by SVI and right atrial pressure (RAP) at baseline and follow-up. The association between RV function parameters and SVI and RAP stratification with long-term outcomes was assessed.

RESULTS

In PATENT-1 (n = 341) and CHEST-1 (n = 238), riociguat improved RV function parameters vs placebo (p < 0.05). At follow-up, there were significant differences in RRS between patients with favorable and unfavorable SVI and RAP, irrespective of treatment arm (p < 0.0001). Multiple RV function parameters at baseline and follow-up were associated with survival and clinical worsening-free survival (CWFS) in PATENT-2 (n = 396; p < 0.05) and CHEST-2 (n = 237). In PATENT-2, favorable SVI and RAP at follow-up only was associated with survival and CWFS (p < 0.05), while in CHEST-2, favorable SVI and RAP at baseline and follow-up were associated with survival and CWFS (p < 0.05).

CONCLUSION

This post hoc analysis of PATENT and CHEST suggests that riociguat improves RV function in patients with PAH and CTEPH.

Peripheral Arterial Stiffness in Acute Pulmonary Embolism and Pulmonary Hypertension at Short-Term Follow-Up

Chronic thromboembolic pulmonary hypertension (CTEPH) is a severe and under-recognized complication of acute pulmonary embolism (PE). Forty consecutive patients with acute PE (Group 1), predominantly female (22, 55%) with a mean age of 69 ± 15 years, were matched for demographic data with 40 healthy subjects (Group 2), 40 systemic hypertension patients (Group 3) and 45 prevalent idiopathic pulmonary arterial hypertension (IPAH) patients (Group 4). The baseline evaluation included physical examination, NYHA/WHO functional class, right heart catheterization (RHC) limited to IPAH patients, echocardiographic assessment and systemic arterial stiffness measurement by cardio-ankle vascular index (CAVI). Patients with PE underwent an echocardiographic evaluation within 1 month from hospital discharge (median 27 days; IQR 21–30) to assess the echo-derived probability of PH. The CAVI values were significantly higher in the PE and IPAH groups compared with the others (Group 1 vs. Group 2, p < 0.001; Group 1 vs. Group 3, p < 0.001; Group 1 vs. Group 4, p = ns; Group 4 vs. Group 2, p < 0.001; Group 4 vs. Group 3, p < 0.001; Group 2 vs. Group 3, p = ns). The predicted probability of echocardiography-derived high-risk criteria of PH increases for any unit increase of CAVI (OR 9.0; C.I.3.9–20.5; p = 0.0001). The PE patients with CAVI ≥ 9.0 at the time of hospital discharge presented an increased probability of PH. This study highlights a possible positive predictive role of CAVI as an early marker for the development of CTEPH.

Echocardiography in Pulmonary Arterial Hypertension: Is It Time to Reconsider Its Prognostic Utility?

Pulmonary arterial hypertension (PAH) is characterized by an insult in the pulmonary vasculature, with subsequent right ventricular (RV) adaptation to the increased afterload that ultimately leads to RV failure. The awareness of the importance of RV function in PAH has increased considerably because right heart failure is the predominant cause of death in PAH patients. Given its wide availability and reduced cost, echocardiography is of paramount importance in the evaluation of the right heart in PAH. Several echocardiographic parameters have been shown to have prognostic implications in PAH; however, the role of echocardiography in the risk assessment of the PAH patient is limited under the current guidelines. This review discusses the echocardiographic evaluation of the RV in PAH and during therapy, and its prognostic implications, as well as the potential significant role of repeated echocardiographic assessment in the follow-up of patients with PAH.

Animal models of pulmonary hypertension: Getting to the heart of the problem

Despite recent therapeutic advances, pulmonary hypertension (PH) remains a fatal disease due to the development of right ventricular (RV) failure. At present, no treatments targeted at the right ventricle are available, and RV function is not widely considered in the preclinical assessment of new therapeutics. Several small animal models are used in the study of PH, including the classic models of exposure to either hypoxia or monocrotaline, newer combinational and genetic models, and pulmonary artery banding, a surgical model of pure RV pressure overload. These models reproduce selected features of the structural remodelling and functional decline seen in patients and have provided valuable insight into the pathophysiology of RV failure. However, significant reversal of remodelling and improvement in RV function remains a therapeutic obstacle. Emerging animal models will provide a deeper understanding of the mechanisms governing the transition from adaptive remodelling to a failing right ventricle, aiding the hunt for druggable molecular targets.

Risk Reduction and Hemodynamics with Initial Combination Therapy in Pulmonary Arterial Hypertension

Rationale: An initial oral combination of drugs is being recommended in pulmonary arterial hypertension (PAH), but the effects of this approach on risk reduction and pulmonary vascular resistance (PVR) are not known.Objectives: To test the hypothesis that a low-risk status would be determined by the reduction of PVR in patients with PAH treated upfront with a combination of oral drugs.Methods: The study enrolled 181 treatment-naive patients with PAH (81% idiopathic) with a follow-up right heart catheterization at 6 months (interquartile range, 144-363 d) after the initial combination of endothelin receptor antagonist + phosphodiesterase-5 inhibitor drugs and clinical evaluation and risk assessments by European guidelines and Registry to Evaluate Early and Long-Term PAH Disease Management scores.Measurements and Main Results: Initial combination therapy improved functional class and 6-minute-walk distance and decreased PVR by an average of 35% (median, 40%). One-third of the patients had a decrease in PVR <25%. This poor hemodynamic response was independently predicted by age, male sex, pulmonary artery pressure and cardiac index, and at echocardiography, a right/left ventricular surface area ratio of greater than 1 associated with low tricuspid annular plane systolic excursion of less than 18 mm. A low-risk status at 6 months was achieved or maintained in only 34.8% (Registry to Evaluate Early and Long-Term PAH Disease Management score) to 43.1% (European score) of the patients. Adding criteria of poor hemodynamic response improved prediction of a low-risk status.Conclusions: A majority of patients with PAH still insufficiently improved after 6 months of initial combinations of oral drugs is identifiable at initial evaluation by hemodynamic response criteria added to risk scores.

The Growing Role of Echocardiography in Pulmonary Arterial Hypertension Risk Stratification: The Missing Piece

Pulmonary arterial hypertension (PAH) is a rare, progressive disease with a poor prognosis. The pathophysiologic model is mainly characterized by an afterload mismatch in which an increased right ventricle afterload, driven by increased pulmonary vascular resistance (PVR), leads to right heart failure. International guidelines recommend optimization of treatment based on regular risk assessments to achieve or maintain a low-risk status. Current risk scores are based on a multi-modality approach, including demographic, clinical, functional, exercise, laboratory, and hemodynamic parameters, which lack significant echocardiographic parameters. The originality of echocardiography relies on the opportunity to assess in a non-invasive way a physiologically meaningful combination of easy to measure variables tightly related to right ventricle adaptation/maladaptation to increased afterload, the main determinant of a patient's prognosis. Echo-derived morphological and functional parameters have been investigated in PAH, proving to have prognostic relevance. Different therapeutic strategies proved to have different effects in reducing PVR. An upfront combination of drugs, including a parenteral prostacyclin, has shown to be associated with right heart reverse remodeling in a greater proportion of patients than other treatment strategies as a function of PVR reduction. Adding echocardiographic data to current risk scores would allow better identification of right ventricle (RV) adaptation in PAH patients' follow-up. This additional information would allow better stratification of the patient, leading to optimized and personalized therapeutic management.

Balloon Pulmonary Angioplasty in Patients with Chronic Thromboembolic Pulmonary Hypertension: Impact on Clinical and Hemodynamic Parameters, Quality of Life and Risk Profile

Balloon pulmonary angioplasty (BPA) is a novel treatment option for patients with chronic thromboembolic pulmonary hypertension (CTEPH) who are not eligible for pulmonary endarterectomy (PEA) or suffer from persistent pulmonary hypertension after PEA. The aim of this study was to evaluate the real-life efficacy and safety of BPA in a consecutive group of patients who were diagnosed and treated in the national referral center for CTEPH in the Czech Republic. Here we report data from 160 BPA procedures performed in 64 patients. Efficacy analysis was performed in the subgroup of 25 patients who completed BPA series. Significant improvements were observed in New York Heart Association functional class (4% to 79% in I/II, p < 0.001), 6 min walking test distance (+54.3 m, p < 0.001), risk profile (15.8% to 68.5% with presence of 2/3 low risk criteria, p < 0.001), pulmonary artery mean pressure (−18%, p < 0.001), pulmonary vascular resistance (−32%, p < 0.001), stroke volume (+17%, p = 0.011) and quality of life (+37% in assessment of overall health status by a patient, p < 0.001). We observed 1 fatal periprocedural complication (1.6% of all 64 patients) and 19 BPA-related non-fatal complications (11.9% of all 160 interventions) that predominantly included hemoptysis (10.0% of all sessions). Overall survival at 12 months was 94.6%.

Initial combination therapy of macitentan and tadalafil in pulmonary arterial hypertension

Initial combination therapy plays a central role in managing pulmonary arterial hypertension (PAH) [1–4]. Patients with low- or intermediate-risk of 1-year mortality at diagnosis should be treated with initial combination therapy with an endothelin receptor antagonist (ERA) and phosphodiesterase type-5 inhibitor (PDE5i) [2–4]. Benefits of initial therapy with the ERA ambrisentan and PDE5i tadalafil were demonstrated in AMBITION [1]; prospective evidence for other treatment combinations within these drug classes is needed.

Initial combination therapy with macitentan and tadalafil is well tolerated and improves cardiopulmonary haemodynamics and functional capacity in newly diagnosed PAH patientshttps://bit.ly/3aWZagH

Initial combination therapy of macitentan and tadalafil in pulmonary arterial hypertension

Initial combination therapy with macitentan and tadalafil is well tolerated and improves cardiopulmonary haemodynamics and functional capacity in newly diagnosed PAH patients https://bit.ly/3aWZagH

Hemodynamics and risk assessment 2 years after the initiation of upfront ambrisentan‒tadalafil in pulmonary arterial hypertension

BACKGROUND

Upfront combination therapy with ambrisentan and tadalafil has been reported to improve the condition of patients with pulmonary arterial hypertension (PAH) more than with either drug alone. However, little is known about the long-term associated changes in hemodynamics and risk assessment scores.

METHODS

This was a multicenter, retrospective analysis of clinical data in 106 patients with newly diagnosed PAH. Clinical evaluations, including demographics, medical history, World Health Organization (WHO) functional class (FC) and 6-minute walk distance (6MWD), right heart catheterization, and Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL) risk score 2.0, were assessed over 48 months of ambrisentan‒tadalafil therapy.

RESULTS

At baseline, 9 patients (9%) showed a low (<7), 48 patients (45%) showed an intermediate (7-8), and 49 patients (46%) showed a high (>8) REVEAL risk score. At a median follow-up of 2 years, 45 patients (43%) showed a low, 47 patients (44%) showed an intermediate, and 14 patients (13%) showed a high REVEAL score, along with improvements in WHO FC, 6MWD and a decrease in mean pulmonary artery pressure and N-terminal pro brain natriuretic peptide (all p < 0.001). Pulmonary vascular resistance (PVR) decreased by 37% from 11.5 ± 6.5 to 7.2 ± 4.1 Wood units (p < 0.001). A total of 61 patients (57%) remained in intermediate-risk or high-risk categories. Low-risk patients had either a decrease in PVR of >50% or a stroke volume within the limits of normal.

CONCLUSIONS

Initial combination therapy with ambrisentan and tadalafil in PAH improves the REVEAL risk score in proportion to decreased PVR and preserved stroke volume but still insufficiently so in approximately 50% of the patients.

Clinical implications of idiopathic pulmonary arterial hypertension phenotypes defined by cluster analysis

BACKGROUND

>Despite advances in drug development, life expectancy in idiopathic pulmonary arterial hypertension (IPAH) remains unacceptable. Contemporary IPAH characterization is based on criteria that may not adequately capture disease heterogeneity and may be proposed as a possible explanation for why patient outcome is still unfavorable. The aim of this study was to apply cluster analysis to improve phenotyping of patients with IPAH and analyze long-term clinical outcome of derived clusters.

METHODS

Patients with IPAH from 2 referral centers (n = 252) were evaluated with clinical, hemodynamic, and echocardiographic assessment and cardiopulmonary exercise test. Patients were classified according to cluster analysis and followed for clinical worsening occurrence.

RESULTS

The cluster analysis identified 4 IPAH phenotypes. Cluster 1 was characterized by young patients, mild pulmonary hypertension (PH), mild right ventricular (RV) dilation and high oxygen (O₂) pulse; Cluster 2 by severe PH and RV dilation and high O₂ pulse; and Cluster 3 by male patients, severe PH and RV dilation, and low O₂ pulse. Cluster 4 patients were older and overweight, with mild PH and RV dilation and low O₂ pulse. After a mean follow-up of 995 ± 623 days, 123 (48.8%) patients had clinical worsening. Cluster 1 patients presented the best prognosis, whereas Cluster 3 had the highest rates of clinical worsening. Compared with Cluster 1, risk of clinical worsening ranged from 4.12 (confidence interval [CI] 1.43-11.92; p = 0.009) for Cluster 4 to 7.38 (CI 2.80-19.40) for Cluster 2 and 13.8 (CI 5.60-34.0; p = 0.0001) for Cluster 3.

CONCLUSIONS

Cluster analysis of clinical variables identified 4 distinct phenotypes of IPAH. Our findings underscore the high degree of disease heterogeneity that exists within patients with IPAH and the need for advanced clinical testing to define phenotypes to improve treatment strategy decision-making. CONDENSED ABSTRACT Idiopathic pulmonary arterial hypertension (IPAH) characterization is based on criteria that may not adequately capture disease heterogeneity. The aim of this study was to apply cluster analysis to improve phenotyping of IPAH. Patients with IPAH (n = 252) were evaluated with clinical, hemodynamic, and echocardiographic assessment and cardiopulmonary exercise test. Within the umbrella category of IPAH, it was the combination of mean pulmonary arterial pressure, right ventricular size, and oxygen pulse that further stratified patients into novel IPAH phenotypes that significantly associate with clinical worsening. These findings underscore the need for novel multidimensional IPAH phenotyping for improved patient care and trial quality.

Right heart failure in pulmonary hypertension: Diagnosis and new perspectives on vascular and direct right ventricular treatment

Adaptation of right ventricular (RV) function to increased afterload-known as RV-arterial coupling-is a key determinant of prognosis in pulmonary hypertension. However, measurement of RV-arterial coupling is a complex, invasive process involving analysis of the RV pressure-volume relationship during preload reduction over multiple cardiac cycles. Simplified methods have therefore been proposed, including echocardiographic and cardiac MRI approaches. This review describes the available methods for assessment of RV function and RV-arterial coupling and the effects of pharmacotherapy on these variables. Overall, pharmacotherapies for pulmonary hypertension have shown beneficial effects on various measures of RV function, but it is often unclear if these are direct RV effects or indirect results of afterload reduction. Studies of the effects of pharmacotherapies on RV-arterial coupling are limited and mostly restricted to experimental models. Simplified methods to assess RV-arterial coupling should be validated and incorporated into routine clinical follow-up and future clinical trials. LINKED ARTICLES: This article is part of a themed issue on Risk factors, comorbidities, and comedications in cardioprotection. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.1/issuetoc.

Cardiac magnetic resonance imaging as a prognostic biomarker in treatment-naïve pulmonary hypertension

PURPOSE

Targeted treatment for pulmonary arterial hypertension (PAH), diagnosed via right heart catheterization (RHC), has been shown to improve morbidity and mortality. Identifying characteristics that predict clinical worsening has been challenging. We sought to evaluate the role of cardiac Magnetic Resonance Imaging (CMR) as a predictor of clinical worsening in a cohort of treatment-naïve pulmonary hypertension (PH) patients.

METHODS

We performed a retrospective single center analysis of all adults with newly diagnosed treatment-naïve PH between January 1st 2013 and January 1st 2019. Patients with World Health Organization (WHO)-Group I PAH or WHO-Group II/III PH disease, who underwent both CMR (Signa Horizon 1.5 T, General Electric, Milwaukee, WI and Siemens Espree 1.5 T, Munich, Germany) and RHC testing prior to targeted PAH treatment, were included for analysis. Cox proportional hazards models were constructed.

RESULTS

A total of 38 patients, of which 12 (32 %) experienced the primary outcome of clinical worsening. were included in the final analysis, Patients with clinical worsening were significantly more likely to have RV dysfunction by CMR (including lower RV ejection fraction (HR 0.93, p = 0.007) and more RV dilation (HR 1.02, p = 0.005-0.021)) and RHC (including worse pulmonary vascular resistance (HR 1.32, p < 0.001)), even after adjustment for disease severity. Both CMR and RHC measures of RV dysfunction were found to be equally effective in predicting clinical worsening, regardless of PH etiology.

CONCLUSIONS

In treatment-naïve PH patients, including those with WHO-Group II/III disease, both CMR and RHC measures independently and significantly predicted clinical worsening, even after adjustment for disease severity.

A Bayesian Network Meta-analysis of Add-on Drug Therapies Specific for Pulmonary Arterial Hypertension

Background: Recently published meta-analyses did not discriminate between drug agents used for initial and sequential combination therapy. Objective: To assess the comparative efficacy of drugs specific for the treatment of pulmonary arterial hypertension (PAH) as add-on therapies based on 6-minute walk distance (6MWD), all-cause mortality, and discontinuation due to adverse events (AEs). Methods: EMBASE, PubMed, Cochrane Library, and ClinicalTrials.gov were searched until December 9, 2018, for the randomized, placebo-controlled clinical trials (RCTs) conducted on primarily adult patients diagnosed with PAH. Data extracted from applicable RCTs were as follows: for 6MWD mean change from baseline, the total number of patients, and the number of patients with events, per treatment. Network meta-analysis (NMA) was conducted in a Bayesian framework. Results: A total of 16 RCTs were eligible for analysis, with 4112 patients. Add-on therapy with tadalafil or inhaled treprostinil performed better than endothelin receptor antagonists alone [27 m; 95% credible interval (CrI): (11, 43); and 19 m; 95% CrI: (10, 27); respectively]. Add-on therapy with macitentan or bosentan performed better than phosphodiesterase type 5 inhibitors alone [26 m; 95% CrI: (6.4, 45); and 22 m; 95% CrI: (5.1, 38); respectively]. Differences in all-cause mortality and discontinuation due to AEs were nonsignificant. Conclusion and Relevance: Our NMA evaluated efficacy and safety of add-on therapies in patients with PAH. None of the previous meta-analyses evaluated RCTs focusing solely on patients pretreated with another PAH-specific drug therapy. Our results support guideline recommendations on combination therapy in PAH patients and add the quantitative perspective on which sequential therapy demonstrated the greatest effect size.

Risk Reduction and Right Heart Reverse Remodeling by Upfront Triple Combination Therapy in Pulmonary Arterial Hypertension

BACKGROUND

Combinations of therapies are currently recommended for patients with severe pulmonary arterial hypertension (PAH), and excellent results have been reported with triple upfront combination of these drugs. We evaluated the effects of this approach on right ventricular (RV) function and outcome in patients with severe PAH.

METHODS

Twenty-one patients (age, 44 ± 15 years) with newly diagnosed high-risk idiopathic PAH that was nonreversible by the inhalation of nitric oxide were treated upfront with a combination of ambrisentan, tadalafil, and subcutaneous treprostinil between 2014 and 2018. Clinical evaluation, World Health Organization functional class, 6-min walk distance, biomarkers, echocardiography, and right-sided heart catheterization data were recorded at baseline and during follow-up.

RESULTS

At a median follow-up of 2 years, all patients were still alive. The Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management score decreased from 10 ± 1 to 5 ± 1, right-sided atrial pressure decreased from 13 ± 3 to 5 ± 2 mm Hg, mean pulmonary artery pressure decreased from 60 ± 9 to 42 ± 5 mm Hg, pulmonary vascular resistance (PVR) decreased from 16.4 ± 4.4 to 5.5 ± 1.3 Wood units, N-terminal pro-brain natriuretic peptide decreased from 3,379 ± 1,921 to 498 ± 223 pg/mL, and World Health Organization functional class decreased from 3.4 ± 0.5 to 2.0 ± 0.4 (all P < .001). Cardiac index increased from 1.8 ± 0.3 to 3.5 ± 0.8 L/min/m² and 6-min walk distance increased from 158 ± 130 to 431 ± 66 m (both P < .001). Echocardiography showed decreased right-sided atrial and RV areas, improved left ventricular eccentricity index, and increased fractional area change (all P < .001) in proportion to treatment-induced decrease in PVR.

CONCLUSIONS

Triple upfront combination therapy with ambrisentan, tadalafil, and subcutaneous treprostinil in severe nonreversible PAH is associated with considerable clinical and hemodynamic improvement and right-sided heart reverse remodeling.

Clinical and hemodynamic benefit of macitentan and riociguat upfront combination in patients with pulmonary arterial hypertension

In this open-label study, we evaluated the effect of upfront macitentan and riociguat combination in newly diagnosed pulmonary arterial hypertension (PAH) patients. In 15 consecutive PAH patients, we collected clinical and hemodynamic data at baseline, visit 1 (median 4 months) and visit 2 (median 12 months). Survival and transplantation status were analyzed over 36 months. Statistical analysis included student t-test and 95% confidence interval (CI) ( t-statistic or Clopper-Pearson). Kaplan-Meier was used to estimate survival rate. There were 11/15 women (mean age 56 years), in World Health Organization (WHO) functional class (FC) III ( n = 14) or IV ( n = 1). The 6 min walk distance increased from 281.6 m (baseline) to 315.7 m (visit 1) and visit 2 (313.9 m), representing a 34- and 32-m change ( P < 0.05), respectively, associated with Borg score improvements. Brain natriuretic peptide decreased: 318.2 pg/mL (baseline) to 122.0 pg/mL (visit 1) and 98.6 pg/mL (visit 2) ( P < 0.05). WHO FC improved in eight patients (53%, 95% CI 27%-79%). Pulmonary vascular resistance (9.2 to 5.7 Wood Units) and mean pulmonary artery pressure (47.3 to 38.9 mmHg) decreased; cardiac index increased (2.3 to 3.0 L/min/m²) (baseline to visit 2, all P < 0.05). All patients had intermediate and high risk score (baseline); at 1-year follow-up, dual therapy led to reduction to low risk score in 7/15 (47%) patients. There were no unexpected or serious side effects. Three patients died due to unrelated causes; one patient received a lung transplant. Transplant-free survival rate (36 months) was 85%. Preliminary evidence is provided for effectiveness of initial macitentan and riociguat combination therapy in PAH.

The Right Heart-Pulmonary Circulation Unit: Physiopathology

The most common cause of right heart failure is increased afterload caused by pulmonary hypertension. Right ventricular function adaptation to increased afterload is basically systolic, with secondary increase in dimensions and systemic congestion. Increased right ventricular dimensions and decreased ejection fraction are associated with a decreased survival in severe pulmonary hypertension. Targeted therapies titrated to reverse the right ventricular remodeling dimensions improve survival in severe pulmonary hypertension.

Real-life experience of inhaled iloprost for patients with pulmonary arterial hypertension: Insights from the Spanish REHAP registry

INTRODUCTION

REHAP is a voluntary, observational Spanish registry of patients with pulmonary arterial hypertension. We analyzed the experience (use and effectiveness) with inhaled iloprost (inh-ILO) in real-life conditions during a 3-year period.

METHODS

Patients included were those with PAH ≥14 years recruited during 1998-2016 who had received inh-ILO. Variables were collected at the beginning of treatment (0 ± 3 months) and 12 ± 3/36 ± 6 months follow-up. Effectiveness was assessed in the intent-to-treat population as changes in functional class and/or physical performance and transplant-free survival from the beginning of treatment. Stopping inh-ILO-related survival was also assessed. Subanalyses included treatment strategy (first-line therapy -monotherapy or upfront combination- or sequential therapy) and risk of clinical worsening/death.

RESULTS

Inh-ILO was the most frequently used prostanoid in Spain, rendering 267 patients eligible for analysis. Median age was 54 years; 61% were WHO FC III. Sixty (23%) patients started inh-ILO as monotherapy, 27 (10%) as upfront combination and 180 (67%) sequentially. At 3-year follow-up significant clinical improvements were observed; however, transplant-free survival rate was 54%, being poorer in patients at high risk (63% vs. 85% in low risk patients; P < 0.001) and similar in the three treatment strategies. Only 25% patients remained on inh-ILO. Three-year after stopping inh-ILO-related survival rate was 24.7%.

CONCLUSION

Data from the REHAP collected during 3 years shows that inh-ILO has low effectiveness independently of the treatment strategy used, with a 3-year survival rate of 54% despite significant clinical improvements, probably due to the use in high-risk patients. Discontinuation rate was as high as 75%.