Clinical significance of the pulmonary vasodilator response during short-term infusion of prostacyclin in primary pulmonary hypertension

Comparison of intravenous sildenafil with inhaled nitric oxide for acute vasodilator testing in pulmonary arterial hypertension

Acute vasodilator testing (AVT) identifies acute responders for initiation of calcium channel blockers in pulmonary arterial hypertension (PAH) and operability in congenital heart disease (CHD). We sought to determine the feasibility of intravenous sildenafil (ivS) as an alternative to inhaled nitric oxide (iNO) in AVT. All patients with PAH undergoing cardiac catheterization for AVT (November 2015 to December 2020) were prospectively enrolled. Hemodynamic data were obtained at baseline, with iNO 20 ppm and ivS (0.25 mg/kg for children and 10 mg for adults). We studied 44 patients with a mean age of 20.5 ± 14.4 years (27 [61%] females and 20 [45%] children). There were 17 (38.6%) patients in the CHD group for operability assessment and 27 patients in non-CHD group (idiopathic pulmonary arterial hypertension-16 [36.3%], residual PAH after shunt closure-7 [15.9%], and 2 cases [4.5%] each of familial PAH and portopulmonary hypertension). There was an excellent intraclass correlation for mean pulmonary artery pressures (0.903, 95% confidence interval, CI: 0.809-0.949, p < 0.001), mean aortic pressures (0.745, 95% CI: 0.552-0.858, p < 0.001), pulmonary vascular resistance index (0.920, 95% CI: 0.858-0.956, p < 0.001), systemic vascular resistance (SVR) index (0.828, 95% CI: 0.706-0.902, p < 0.001), and the ratio of pulmonary and SVR indices (0.857, 95% CI: 0.752-0.919, p < 0.001) between the two agents. There were two responders, both in non-CHD group, and were identified by iNO and ivS. The hemodynamic effects of ivS show excellent correlation with iNO and could be a potential alternative agent for identifying acute responders during AVT.

PeakPETCO2 combined with FEV1/FVC predicts vasodilator-responsive patients with idiopathic pulmonary arterial hypertension

Cardiopulmonary exercise testing and pulmonary function test are important methods for detecting human cardio-pulmonary function. Whether they could screen vasoresponsiveness in idiopathic pulmonary artery hypertension (IPAH) patients remains undefined. One hundred thirty-two IPAH patients with complete data were retrospectively enrolled. Patients were classified as vasodilator-responsive (VR) group and vasodilator-nonresponsive (VNR) group on the basis of the acute vasodilator test. Pulmonary function test and cardiopulmonary exercise testing were assessed subsequently and all patients were confirmed by right heart catheterization. We analyzed cardiopulmonary exercise testing and pulmonary function test data and derived a prediction rule to screen vasodilator-responsive patients in IPAH. Nineteen of VR-IPAH and 113 of VNR-IPAH patients were retrospectively enrolled. Compared with VNR-IPAH patients, VR-IPAH patients had less severe hemodynamic effects (lower RAP, m PAP, PAWP, and PVR). And VR-IPAH patients had higher anaerobic threshold (AT), peak partial pressure of end-tidal carbon dioxide (PETCO2), oxygen uptake efficiency (OUEP), and FEV1/FVC (P all <0.05), while lower peak partial pressure of end-tidal oxygen (PETO2) and minute ventilation (VE)/carbon dioxide output (VCO2) slope (P all <0.05). FEV1/FVC (Odds Ratio [OR]: 1.14, 95% confidence interval [CI]: 1.02-1.26, P = 0.02) and PeakPETCO2 (OR: 1.13, 95% CI: 1.01-1.26, P = 0.04) were independent predictors of VR adjusted for age, sex, and body mass index. A novel formula (=-16.17 + 0.123 × PeakPETCO2 + 0.127×FEV1/FVC) reached a high area under the curve value of 0.8 (P = 0.003). Combined with these parameters, the optimal cutoff value of this model for detection of VR is -1.06, with a specificity of 91% and sensitivity of 67%. Compared with VNR-IPAH patients, VR-IPAH patients had less severe hemodynamic effects. Higher FEV1/FVC and higher peak PETCO2 were associated with increased odds for vasoresponsiveness. A novel score combining PeakPETCO2 and FEV1/FVC provides high specificity to predict VR patients among IPAH.

Advances in the management of pulmonary arterial hypertension

The management of pulmonary arterial hypertension (PAH) has significantly evolved over the last decades in the wake of more sensitive diagnostics and specialized clinical programs that can provide focused medical care. In the current era of PAH care, 1-year survival rates have increased to 86%–90% from 65% in the 1980s, and average long-term survival has increased to 6 years from 2.8 years. The heterogeneity in the etiology and disease course has opened doors to focusing research in phenotyping the disease and understanding the pathophysiology at a cellular and genetic level. This may eventually lead to precision medicine and the development of medications that may prevent or reverse pulmonary vascular remodeling. With more insight, clinical trial designs and primary end-points may change to identify the true survival benefit of pharmacotherapy. Identifying responders from non-responders to therapy may help provide individualized patient-centered care rather than an algorithm-based approach. The purpose of this review is to highlight the latest advances in screening, diagnosis, and management of PAH.

Clinical Presentation, Differential Diagnosis, and Vasodilator Testing of Pulmonary Hypertension

Clinicians should be cognizant of the symptoms and risk factors associated with pulmonary hypertension (PH). While known PH poses significant therapeutic challenges, occult PH carries the added potential for unanticipated complications when treating concurrent medical illnesses. PH may occur with underlying medical conditions and risk factors or may occur de novo as idiopathic pulmonary arterial hypertension (IPAH). Symptoms of PH are frequently attributed to more common conditions, and their nonspecific nature and insidious onset may lead to delay in presentation, evaluation, and diagnosis. Initial symptoms are dyspnea, fatigue, chest pain, and palpitations. Lower extremity edema, presyncope, and syncope are symptoms of more advanced disease. Thorough evaluation of symptoms and identification of patients with risk factors for PH are critical in making a timely diagnosis. History and physical examination can identify patients with suspected PH. Further testing is necessary for definitive diagnosis, classification, assessment of severity, and guiding therapeutic decisions.

Survival benefits of warfarin in Korean patients with idiopathic pulmonary arterial hypertension

BACKGROUND/AIMS

Idiopathic pulmonary arterial hypertension (IPAH) is an incurable disease with high mortality. Although most studies recommend anticoagulation treatment for IPAH, the benefits are uncertain, particularly in Korea, where it has not been studied. The purpose of this study was to evaluate survival outcomes of Korean patients with IPAH treated with warfarin.

METHODS

We performed a retrospective cohort study of patients diagnosed previously with pulmonary arterial hypertension (PAH) at the Asan Medical Center in Korea, between January 1994 and February 2013. We excluded patients with associated PAH, patients who did not undergo right heart catheterization (RHC), and patients with a positive vasoreactivity test. Patients in the study cohort were classified into a "warfarin group" and a "non-warfarin group," according to the treatment they received during the first year after diagnosis.

RESULTS

We identified 31 patients with IPAH and a negative vasoreactivity test on RHC. Median patient age was 36.0 years, and 23 patients (74.2%) were female. The median time from the onset of symptoms to diagnosis was 19.0 months, and the most common presenting symptom was dyspnea. Survival rates of the patients at 1, 3, 5, and 10 years were 90.2%, 79.5%, 62.7%, and 34.8%, respectively. The mean survival period was 12.0 years in the warfarin group and 6.1 years in the non-warfarin group. Warfarin treatment had significant survival benefits in patients with IPAH (p = 0.023).

CONCLUSIONS

Warfarin treatment substantially improved survival outcomes in Korean cases of IPAH.

Role of Vasodilator Testing in Pulmonary Hypertension

Pulmonary hypertension is clinically defined by a mean pulmonary artery (PA) pressure of 25mm Hg or more at rest, as measured by right heart catheterization. To identify patients who are likely to have a beneficial response to calcium channel blockers (CCBs) and therefore a better prognosis, acute vasodilator testing should be performed in patients in certain subsets of pulmonary arterial hypertension (PAH). A near normalization of pulmonary hemodynamics is needed before patients can be considered for therapy with CCBs. Intravenous adenosine, intravenous epoprostenol, inhaled nitric oxide, or inhaled iloprost are the standard agents used for vasoreactivity testing in patients with idiopathic PAH. In this review we describe the various aspects of vasodilator testing including the rationale, pathophysiology and agents used in the procedure.

Epoprostenol sodium for treatment of pulmonary arterial hypertension

The release of endogenous prostacyclin (PGI2) is depressed in patients with pulmonary arterial hypertension (PAH). PGI2 replacement therapy by epoprostenol infusion is one of the best treatments available for PAH. Here, we provide an overview of the current clinical data for epoprostenol. Epoprostenol treatment improves symptoms, exercise capacity, and hemodynamics, and is the only treatment that has been shown to reduce mortality in patients with idiopathic PAH (IPAH) in randomized clinical trials. We have reported that high-dose epoprostenol therapy (>40 ng/kg/min) also results in marked hemodynamic improvement in some patients with IPAH. High-dose epoprostenol has a pro-apoptotic effect on PAH-PASMCs via the IP receptor and upregulation of Fas ligand (FasL) in vitro. However, long-term intravenous administration of epoprostenol is sometimes associated with catheter-related infections and leads to considerable inconvenience for the patient. In the future, the development of new routes of administration or the development of powerful PGI2 analogs, IP-receptor agonists, and gene and cell-based therapy enhancing PGI2 production with new routes of administration is required.

Prognostic value of acute vasodilator response in pulmonary arterial hypertension: beyond the "classic" responders

BACKGROUND

A "classic" response to acute vasodilator testing (drop of >10 mm Hg in mean pulmonary artery pressure [mPAP] to <40 mm Hg) confers an excellent prognosis in patients with idiopathic pulmonary arterial hypertension (IPAH) and identifies candidates for treatment with calcium channel blockers (CCB). Little is known about vasodilator responsiveness (VR) in other types of PAH, or about outcomes in patients with a significant but "non-classic" decrease in mPAP. We hypothesized that VR occurs in non-idiopathic PAH and non-classic VR portends a better prognosis than no VR in PAH.

METHODS

Acute VR testing with nitric oxide was performed on 155 consecutive patients referred for PH evaluation. Non-classic response was defined as decrease in mPAP >10 mm Hg to >40 mm Hg with preserved cardiac output. Demographics and functional status were assessed at baseline and the first clinic visit after VR testing, and survival was followed over time.

RESULTS

Twenty patients (13%) displayed classic VR. Among classic responders, 12 (60%) had IPAH and 8 (40%) had connective tissue disease-associated PAH (CTD-PAH); however, only responders with IPAH had improved survival compared with non-responders (p = 0.02). Thirteen patients (8%) had a non-classic VR. Non-classic response was not associated with improved survival compared with non-responders (p = 0.86). Acute change in mPAP or pulmonary vascular resistance in the entire cohort did not predict survival.

CONCLUSIONS

Classic acute VR occurs in CTD-PAH as well as IPAH; however, only IPAH patients have improved outcomes. A significant but non-classic VR is not associated with improved survival.

Improved survival of Korean patients with idiopathic pulmonary arterial hypertension after the introduction of targeted therapies

OBJECTIVES

We compared the survival of patients with idiopathic pulmonary arterial hypertension (IPAH), receiving conventional and targeted therapies.

BACKGROUND

IPAH is an incurable disease with high mortality. To manage IPAH, several targeted therapies have been used in Korea.

METHODS

We performed a retrospective study of 71 patients diagnosed with IPAH in a tertiary hospital between January 1994 and February 2013. Patients were classified into "conventional therapy group" (treated with conventional therapies and/or beraprost) and "targeted therapy group" (treated with targeted therapies other than beraprost).

RESULTS

The median age of the patients was 33 years and 50 patients were female. The survival rate at 1, 3, 5, and 10 years was 80.1% 62.0%, 51.5%, and 26.8%, respectively. The survival rate in the targeted therapy group was greater than in the conventional therapy group (p-value = 0.026).

CONCLUSIONS

We believe targeted therapies would improve survival benefits in IPAH patients.

Saudi Guidelines on the Diagnosis and Treatment of Pulmonary Hypertension: Medical and surgical management for pulmonary arterial hypertension

Prior to the availability of the pulmonary arterial hypertension (PAH)-specific therapy, PAH was a dreadful disease with a very poor prognosis. Better understanding of the complex pathobiology of PAH has led to a major therapeutic evolution. International regulatory agencies have approved many specific drugs with different pharmacologic pathways and routes of administration. In the year 2013, two new drugs with great potentials in managing PAH have been added to the treatment options, macitentan and riociguat. Additional drugs are expected to come in the near future.

A substantial body of evidence has confirmed the effectiveness of pulmonary arterial hypertension (PAH)-specific therapies in improving the patients’ symptomatic status and slowing down the rate of clinical deterioration.

Although the newer modern medications have significantly improved the survival of patients with PAH, it remains a non-curable and fatal disease. Lung transplantation (LT) remains the only therapeutic option for selected patients with advanced disease who continue to deteriorate despite optimal therapy.

Noninvasive monitoring of serial changes in pulmonary vascular resistance and acute vasodilator testing using cardiac magnetic resonance

OBJECTIVES

The study sought to evaluate the ability of cardiac magnetic resonance (CMR) to monitor acute and long-term changes in pulmonary vascular resistance (PVR) noninvasively.

BACKGROUND

PVR monitoring during the follow-up of patients with pulmonary hypertension (PH) and the response to vasodilator testing require invasive right heart catheterization.

METHODS

An experimental study in pigs was designed to evaluate the ability of CMR to monitor: 1) an acute increase in PVR generated by acute pulmonary embolization (n = 10); 2) serial changes in PVR in chronic PH (n = 22); and 3) changes in PVR during vasodilator testing in chronic PH (n = 10). CMR studies were performed with simultaneous hemodynamic assessment using a CMR-compatible Swan-Ganz catheter. Average flow velocity in the main pulmonary artery (PA) was quantified with phase contrast imaging. Pearson correlation and mixed model analysis were used to correlate changes in PVR with changes in CMR-quantified PA velocity. Additionally, PVR was estimated from CMR data (PA velocity and right ventricular ejection fraction) using a formula previously validated.

RESULTS

Changes in PA velocity strongly and inversely correlated with acute increases in PVR induced by pulmonary embolization (r = -0.92), serial PVR fluctuations in chronic PH (r = -0.89), and acute reductions during vasodilator testing (r = -0.89, p ≤ 0.01 for all). CMR-estimated PVR showed adequate agreement with invasive PVR (mean bias -1.1 Wood units,; 95% confidence interval: -5.9 to 3.7) and changes in both indices correlated strongly (r = 0.86, p < 0.01).

CONCLUSIONS

CMR allows for noninvasive monitoring of acute and chronic changes in PVR in PH. This capability may be valuable in the evaluation and follow-up of patients with PH.

Pulmonary hypertension: Hemodynamic evaluation. Updated Recommendations of the Cologne Consensus Conference 2011

The 2009 European Guidelines on Diagnosis and Treatment of Pulmonary Hypertension have been adopted for Germany. The guidelines contain detailed recommendations for the diagnosis of pulmonary hypertension. However, the practical implementation of the European Guidelines in Germany requires the consideration of several country-specific issues and already existing novel data. This requires a detailed commentary to the guidelines, and in some aspects an update already appears necessary. In June 2010, a Consensus Conference organized by the PH working groups of the German Society of Cardiology (DGK), the German Society of Respiratory Medicine (DGP) and the German Society of Pediatric Cardiology (DGPK) was held in Cologne, Germany. This conference aimed to solve practical and controversial issues surrounding the implementation of the European Guidelines in Germany. To this end, a number of working groups was initiated, one of which was specifically dedicated to the invasive hemodynamic evaluation of pulmonary hypertension. This manuscript describes in detail the results and recommendations of the working group which were last updated in October 2011.

Overview of current therapeutic approaches for pulmonary hypertension

There have been tremendous strides in the management of pulmonary hypertension over the past 20 years with the introduction of targeted medical therapies and overall improvements in surgical treatment options and general supportive care. Furthermore, recent data shows that the survival of those with pulmonary arterial hypertension is improving. While there has been tremendous progress, much work remains to be done in improving the care of those with secondary forms of pulmonary hypertension, who constitute the majority of patients with this disorder, and in the optimal treatment approach in those with pulmonary arterial hypertension. This article will review general and targeted medical treatment, along with surgical interventions, of those with pulmonary hypertension.

Vasoreactivity to inhaled nitric oxide with oxygen predicts long-term survival in pulmonary arterial hypertension

Pulmonary vasodilator testing is currently used to guide management of patients with pulmonary arterial hypertension (PAH). However, the utility of the pulmonary vascular response to inhaled nitric oxide (NO) and oxygen in predicting survival has not been established. Eighty patients with WHO Group I PAH underwent vasodilator testing with inhaled NO (80 ppm with 90% O₂ for 10 minutes) at the time of diagnosis. Changes in right atrial (RA) pressure, mean pulmonary artery pressure (mPAP), pulmonary capillary wedge pressure, Fick cardiac output, and pulmonary vascular resistance (PVR) were tested for associations to long-term survival (median follow-up 2.4 years). Five-year survival was 56%. Baseline PVR (mean±SD 850±580 dyne-sec/cm⁵) and mPAP (49±14 mmHg) did not predict survival, whereas the change in either PVR or mPAP while breathing NO and O₂ was predictive. Patients with a ≥30% reduction in PVR with inhaled NO and O₂ had a 53% relative reduction in mortality (Cox hazard ratio 0.47, 95% confidence interval (CI) 0.23-0.99, P=0.047), and those with a ≥12% reduction in mPAP with inhaled NO and O₂ had a 55% relative reduction in mortality (hazard ratio 0.45, 95% CI 0.22-0.96, P=0.038). The same vasoreactive thresholds predicted survival in the subset of patients who never were treated with calcium channel antagonists (n=66). Multivariate analysis showed that decreases in PVR and mPAP with inhaled NO and O₂ were independent predictors of survival. Reduction in PVR or mPAP during short-term administration of inhaled NO and O₂ predicts survival in PAH patients.

Response to inhaled nitric oxide predicts survival in patients with pulmonary hypertension

OBJECTIVE

To examine the ability of vasodilator response to predict survival in a diverse cohort of patients with pulmonary hypertension (PH).

PATIENTS & METHODS

A total of 214 consecutive treatment-naive patients referred for invasive PH evaluation were enrolled between November 1998 and December 2008. Vasoreactivity was assessed during inhalation of 40 parts per million nitric oxide (iNO) and vasodilator responders were defined as those participants who achieved a mean pulmonary artery pressure (PAP) of ≤ 40 mm Hg and a drop in mean PAP ≥ the median for the cohort (13%). Kaplan-Meier analysis and Cox proportional hazards modeling were used to identify predictors of survival.

RESULTS

There were 51 deaths (25.9%) over a mean follow-up period of 2.3 years. Kaplan-Meier analysis demonstrated that vasodilator responders had significantly improved survival (P < .01). Vasodilator responders had improved survival regardless of whether or not they had idiopathic or nonidiopathic PH (P = .02, P < .01) or whether or not they had Dana Point class 1 or non-Dana Point class 1 PH (P < .01, P = .01). In multivariate modeling, advanced age, elevated right atrial pressure, elevated serum creatinine, and worsened functional class significantly predicted shorter survival (P = .01, P = .01, P = .01, P < .01), whereas vasodilator response predicted improved survival (P = .01).

CONCLUSIONS

Vasodilator responsiveness to iNO is an important method of risk stratifying PH patients, with results that apply regardless of clinical etiology.

Pulmonary vasodilator testing and use of calcium channel blockers in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) encompasses a number of diseases responsible for a specific set of hemodynamic findings during right heart catheterization. During initial workup, pulmonary vasodilator testing is performed. A positive acute pulmonary vasodilator test predicts better survival and response to calcium channel blocker (CCB) therapy. There is lack of consensus on the preferred agent for determining acute pulmonary vasoreactivity. The ACCP guidelines and the 4(th) World Symposium on Pulmonary Hypertension support the use of intravenous epoprostenol or nitric oxide (NO) as the preferred agents for pulmonary vasodilator testing. A decrease in the mean pulmonary artery pressure by at least 10 mmHg to reach an absolute value of 40 mmHg or less without a decrease in cardiac output is currently considered a positive pulmonary vasodilator test. A positive test by the current recommended criteria is observed in about 10-15% of patients with idiopathic PAH. Approximately half of these patients will experience long-term benefits with CCBs. A positive test may select patients with an earlier or less aggressive form of disease, which may carry a better prognosis. A positive vasodilator test is observed very infrequently in patients with pulmonary arterial hypertension other than idiopathic PAH or anorexigen associated PAH. This article reviews the literature regarding pulmonary vasodilator testing and use of CCB therapy in patients with PAH, while identifying the gaps in knowledge concerning this diagnostic procedure.

Updated evidence-based treatment algorithm in pulmonary arterial hypertension

Uncontrolled and controlled clinical trials with different compounds and procedures are reviewed to define the risk-benefit profiles for therapeutic options in pulmonary arterial hypertension (PAH). A grading system for the level of evidence of treatments based on the controlled clinical trials performed with each compound is used to propose an evidence-based treatment algorithm. The algorithm includes drugs approved by regulatory agencies for the treatment of PAH and/or drugs available for other indications. The different treatments have been evaluated mainly in idiopathic PAH, heritable PAH, and in PAH associated with the scleroderma spectrum of diseases or with anorexigen use. Extrapolation of these recommendations to other PAH subgroups should be done with caution. Oral anticoagulation is proposed for most patients; diuretic treatment and supplemental oxygen are indicated in cases of fluid retention and hypoxemia, respectively. High doses of calcium-channel blockers are indicated only in the minority of patients who respond to acute vasoreactivity testing. Nonresponders to acute vasoreactivity testing or responders who remain in World Health Organization (WHO) functional class III, should be considered candidates for treatment with either an oral phosphodiesterase-5 inhibitor or an oral endothelin-receptor antagonist. Continuous intravenous administration of epoprostenol remains the treatment of choice in WHO functional class IV patients. Combination therapy is recommended for patients treated with PAH monotherapy who remain in WHO functional class III. Atrial septostomy and lung transplantation are indicated for refractory patients or where medical treatment is unavailable.

Chronic thromboembolic and pulmonary arterial hypertension share acute vasoreactivity properties

BACKGROUND

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are the major classes of pulmonary hypertensive disorders according to the World Health Organization; both lead to right heart failure and death. A better understanding of disease mechanisms has led to the suggestion that the thromboembolic and nonthromboembolic types of pulmonary hypertension may share pathophysiologic features. We therefore compared acute vasoreactivity and proximal pulmonary artery compliance in patients with PAH and CTEPH during the initial diagnostic heart catheterization.

METHODS

Right heart catheterization using a flow-directed Swan-Ganz catheter was performed in patients with CTEPH (n = 22) and PAH (n = 35). Pulmonary hemodynamics were assessed at baseline, during the inhalation of 40 ppm of nitric oxide, and 30 min after the inhalation of 10 mug of iloprost. To assess the proximal pulmonary artery compliance, the pulse pressure (PP) [systolic-diastolic pressure] and the fractional PP (PPf) [divided by the mean pressure] were calculated.

RESULTS

Both vasodilators produced similar hemodynamic improvement, and the difference between CTEPH and PAH was not significant. The baseline PP and PPf did not vary between the two groups.

CONCLUSION

Patients with PAH and CTEPH show similar acute vasoreactivity to inhaled nitric oxide and iloprost, and have similar pulmonary artery compliance. These findings support the presence of some shared pathophysiologic pathways in both disorders and may lead to therapeutic implications in patients with inoperable CTEPH.

Pulmonary Arterial Hypertension after Childhood Cancer Therapy and Bone Marrow Transplantation

According to the Third World Symposium on Pulmonary Arterial Hypertension (PAH), chemotherapy is considered to be one of the possible risk factors for patients developing PAH. However, to date, no literature has sufficiently addressed the risk, natural history, and effective treatment of this condition. We report our experience on how early diagnosis, detailed monitoring of disease course, and appropriate treatment application have led to a successful outcome of PAH management in childhood after cancer therapy. Our report reaffirmed the fact that PAH is now a recognized complication of chemotherapy and bone marrow transplantation for leukemia. Combined pulmonary vasodilator treatment has a beneficial effect in improving the patient's condition and functional status as suggested by initial acute pulmonary vasodilator testing.

Effects of intravenous nesiritide on pulmonary vascular hemodynamics in pulmonary hypertension

BACKGROUND

Nesiritide is effective in the treatment of decompensated heart failure (HF). We evaluated the acute hemodynamic effects of nesiritide, a recombinant B-type natriuretic peptide, in patients with HF and pulmonary hypertension (PH).

METHODS AND RESULTS

Twenty patients with HF and PH (mean pulmonary arterial [PA] pressure >25 mm Hg) were enrolled: 10 with postpulmonary capillary wedge (PCW) >15 mm Hg and 10 with precapillary PH (PCW) < or =15. The pulmonary and systemic hemodynamics were determined by right heart catheterization at baseline and at 15 and 30 minutes after an intravenous nesiritide infusion (2 mcg/kg bolus and 0.01 mcg.kg.min). For the patients with postcapillary PH, the mean left ventricular ejection fraction was 28 +/- 15%. After the 30-minute nesiritide infusion, right atrial (RA) pressure decreased 48% (P < .0001), mean PA pressure decreased 29% (P < .0001), PCW pressure decreased 40% (P < .0001), cardiac index (CI) increased 35% (P = .009), pulmonary vascular resistance index (PVRI) decreased 35% (P = .01), and arteriovenous oxygen difference (AVDO(2)) decreased 27% (P = .0003). For precapillary PH patients, there was no change in RA, PA, or PCW pressure, nor any change in CI, PVRI, or AVDO(2).

CONCLUSIONS

Nesiritide acutely and significantly reduced PA pressure, PVRI, and biventricular filling pressures in patients with postcapillary PH. However, for patients with precapillary PH, nesiritide had no significant acute hemodynamic effect on the pulmonary hemodynamics. The lack of acute beneficial effects of nesiritide in patients with advanced precapillary PH may be related to their relatively fixed remodeling of the pulmonary vasculature.

Pulmonary arterial hypertension

Pulmonary arterial hypertension is a disease of the small pulmonary arteries characterized by vascular narrowing and increased pulmonary vascular resistance, which eventually leads to right ventricular failure. Vasoconstriction, vascular proliferation, remodeling of the pulmonary vessels, and thrombosis are all contributing factors to the increased vascular resistance seen in this disease. Pulmonary arterial hypertension develops as a sporadic disease (idiopathic), as an inherited disorder (familial), or in association with certain conditions (collagen vascular diseases, portal hypertension, human immunodeficiency virus infection, congenital systemic-to-pulmonary shunts, ingestion of drugs or dietary products, or persistent fetal circulation). The pathogenesis of pulmonary arterial hypertension is a complicated, multifactorial process. It seems doubtful that any one factor alone is sufficient to activate the necessary pathways leading to the development of this disease. Rather, clinically apparent pulmonary arterial hypertension most likely develops after a second insult occurs in an individual who is already susceptible owing to genetic factors, environmental exposures, or acquired disorders. Currently, there is no cure for pulmonary arterial hypertension but several novel therapeutic options are now available that can improve symptoms and increase survival.

Les traitements de l’hypertension artérielle pulmonaire à l’heure de la T2A. Recommandations du groupe de travail “Maladies vasculaires pulmonaires” de la Société de pneumologie de langue française

Activity-based financing (that is, casemix-based hospital payments, known as T2A) is intended to harmonize and improve the fairness of remuneration of public and private hospitals. T2A will ultimately rely mainly on a flat rate per admission, set according to the diagnosis-related group (DRG). Although payment for drugs is usually included in the DRG price, some expensive drugs will be reimbursed on an additional cost basis after implementation of a "best practices" agreement. Four drugs used for treatment of pulmonary arterial hypertension are eligible for this additional reimbursement: 3 prostacyclin derivatives (intravenous epoprostenol, inhaled iloprost, and subcutaneous treprostinil), and oral bosentan, an endothelin receptor antagonist. The Pulmonary Vascular Diseases working group of the French Society of Pulmonary Medicine has developed guidelines for the best practices in use of these drugs.

Pulmonary Hypertension in Sickle Cell Disease: Mechanisms, Diagnosis, and Management

Pulmonary hypertension affects nearly one-third of adults with sickle cell disease and is related to hemolysis. Although pulmonary pressures are not as high as in other forms of pulmonary hypertension, sickle cell patients poorly tolerate even moderate elevations of pulmonary pressures, because this complication predicts short survival. Tricuspid regurgitant jet velocity measured noninvasively by echocardiography is an adequate tool to screen for pulmonary hypertension. Because patients with pulmonary hypertension are older and often severely affected by other vaso-occlusive complications, optimizing their treatment with hydroxyurea or transfusions is important. Newer agents such as sildenafil and bosentan have demonstrated efficacy in other forms of pulmonary hypertension, and future clinical trials may prove them helpful in sickle cell patients.

Acute vasodilator test in pulmonary arterial hypertension: Evaluation of two response criteria

The rationale for the acute vasodilator test in idiopathic pulmonary arterial hypertension (IPAH) is to identify patients who have a vasoreactive component that justifies the use of non-selective vasodilators. We tested the ability of two different response criteria to identify such patients studying 34 patients with IPAH. The hemodynamic data from the right heart catheterization were collected at baseline and post-administration of inhaled nitric oxide. We describe the results obtained by two different response criteria: (A) a 20% decrease in indexed pulmonary vascular resistance (PVRi) and in mean pulmonary artery pressure(PAPm)(classic criterion); (B) a fall in PAPm of at least 10 mm Hg to a pressure level of 40 mm Hg or lower (revised criterion). Patients who responded according to the revised criterion showed a higher cardiac index (CI) (3.45+/-1.94 vs. 1.99+/-0.44 L/min/m2; p=0.05) and lower PVRi (1247+/-746 vs. 2437+/-1105 dyn cm-5 s m2; p=0.02) compared to non-responders. Responders according to the classic criterion had a statistically significant lower CI (1.59+/-0.40 vs. 2.43+/-1.14 L/min/m2; p=0.03) and higher PVRI (3130+/-1173 vs. 1958+/-980 dyn cm-5 s m2; p=0.04) also compared to non-responders. We conclude that the revised criterion seems to reflect the degree of vascular remodeling more accurately, identifying patients with better preserved cardiac function, possibly in an earlier phase of the disease.

Current treatment strategies for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a disease characterized by an elevation in pulmonary artery pressure that can lead to right ventricular failure and death. Although there is no cure for PAH, newer medical therapies have been shown to improve a variety of clinically relevant end-points including survival, exercise tolerance, functional class, haemodynamics, echocardiographic parameters and quality of life measures. Since the introduction of continuous intravenous prostacyclin, the treatment armamentarium of approved drugs for PAH has expanded to include prostacyclin analogues with differing routes of administration, a dual endothelin receptor antagonist, and a phosphodiesterase-5 inhibitor. Selective endothelin-A receptor antagonists have shown promise in clinical trials and are likely to be added to the list of options. As the number of medications available for PAH continues to increase, treatment decisions regarding first-line therapy, combination treatments, and add-on strategies are becoming more complex. This article reviews the current treatments strategies for PAH and provides guidelines for its management.

Avaliação hemodinâmica da hipertensão pulmonar

A avaliação hemodinâmica é parte essencial tanto para a definição diagnóstica e prognóstica dos quadros de hipertensão pulmonar, quanto para a definição do tratamento inicial, ou mesmo na avaliação da resposta terapêutica. De acordo com a fase em que a avaliação é realizada, alguns aspectos mais relevantes merecem especial atenção, como o valor da pressão de oclusão da artéria pulmonar e do débito cardíaco, ou ainda a resposta aguda aos vasodilatadores. Embora formas não invasivas de avaliação da circulação pulmonar estejam cada vez mais desenvolvidas, a avaliação hemodinâmica ainda é mandatória nos quadros de hipertensão arterial pulmonar.

Critérios prognósticos em hipertensão arterial pulmonar

Com o advento de novas terapias para o tratamento da hipertensão arterial pulmonar, surge a necessidade de se definir marcadores prognósticos que, em última análise, reflitam a melhora da qualidade de vida e da sobrevida dos pacientes frente a essas novas opções terapêuticas. Até o momento, o teste de caminhada de seis minutos foi o principal marcador utilizado para a definição do benefício das terapias disponíveis. Porém, marcadores clínicos, de qualidade de vida e biológicos apresentam grande potencial para o manuseio dos pacientes portadores de hipertensão pulmonar.

Pulmonary and systemic hemodynamic responses to intravenous prostacyclin in broilers

The eicosanoid vasodilator prostacyclin (PGI2) reduces resistance to pulmonary blood flow and attenuates pulmonary hypertension in mammals. However, sparse information is available regarding the responsiveness of the avian pulmonary vasculature to PGI2. Accordingly, in 3 experiments we evaluated the pulmonary vascular responses to PGI2 in male broilers. In experiment 1, infusing PGI2 (10 microg/min) into clinically healthy broilers did not reduce their pulmonary vascular resistance (PVR) but did reduce their pulmonary arterial pressure (PAP) by lowering their cardiac output. Within 4 min after stopping the PGI2 infusion, the cardiac output and PAP returned to preinfusion levels. In experiment 2, the responses to PGI2 were evaluated after arachidonic acid (AA) had been infused to preconstrict the pulmonary vasculature. The AA infusion (400 microg/min) consistently triggered dramatic, sustained pulmonary vasoconstriction (increased PVR) and pulmonary hypertension (increased PAP). Concurrent PGI2 infusions did not reduce PVR but did reduce PAP by lowering cardiac output. Within 4 min after stopping the PGI2 infusion, PAP and cardiac output returned to their previous (hypertensive) levels attributable to the ongoing AA infusion. In experiment 3, PGI2 was infused (10 microg/min) into clinically healthy (PAP < or = 24 mmHg) or subclinically hypertensive (PAP > or = 27 mmHg) broilers. Throughout this experiment broilers in the hypertensive group had higher PAP values than broilers in the healthy group. The PGI2 infusion reduced PAP in both groups but did not reduce PVR. Instead, the pulmonary hypotensive response to PGI2 infusion was associated with a reduction in cardiac output in both groups. In all 3 experiments PGI2 reduced PAP by reducing cardiac output rather than by reducing PVR. There was no evidence that PGI2 acts as an effective pulmonary vasodilator in broilers regardless of whether their pulmonary vasculature was apparently normal (clinically healthy), had been pharmacologically preconstricted (AA infusion), or initially exhibited the vasoconstriction that is typical of the pathogenesis of pulmonary hypertension syndrome in broilers (PAP > or = 27 mmHg). The consistent failure of PGI2 to elicit pulmonary vasodilation in this study suggests fundamental differences in AA metabolism or the etiology of pulmonary hypertension may exist when broilers are compared with mammals.

Comparison of the acute pulmonary vasodilating effect of beraprost sodium and nitric oxide in congenital heart disease

BACKGROUND

Congenital heart disease patients who have pulmonary hypertension (PH) require an evaluation for pulmonary vascular reactivity before surgical repair. In the present study the acute pulmonary vasodilating effects of 100% oxygen (O2), beraprost sodium (BPS) and 40 ppm inhaled nitric oxide (iNO) during cardiac catheterization were compared.

METHODS AND RESULTS

There were 90 patients who underwent cardiac catheterization for evaluation of PH (mean age, 16.5+/-16 years). The baseline mean pulmonary artery (mPA) pressure was 69.6+/-14.8 mmHg and the pulmonary arteriolar resistance (Rpa) was 13.8+/-8.3 Wood unit m2. Change in pulmonary vascular reactivity was defined as a decrease in mPA or Rpa>20% from baseline. The response to 100%O2, iNO and BPS during cardiac catheterization was 84%, 72.7% and 64%, respectively. Pair comparisons among each hemodynamic parameter showed no difference between the acute vasodilating effect of BPS and iNO. In some patients BPS showed a stronger effect than iNO in lowering Rpa.

CONCLUSIONS

BPS has a similar pulmonary vasodilating effect to iNO and can be used as an acute pulmonary vasodilating agent during cardiac catheterization with potential benefits over iNO.

Cardiac catheterization techniques in pulmonary hypertension

Once considered dangerous and potentially life threatening, cardiac catheterization of the patient with pulmonary hypertension can be performed safely and provides essential information in the diagnosis and management of pulmonary hypertension. This article summarizes the modern techniques used for right-heart catheterization, selective pulmonary angiography, and pulmonary angioscopy in the evaluation of the patient with pulmonary hypertension or suspected chronic thromboembolic disease.

Diagnosis and treatment of pulmonary arterial hypertension

The diagnosis of pulmonary hypertension requires a high index of suspicion and careful attention to assessing the severity and classification of disease. Proper evaluation and understanding of determinants of severity in pulmonary arterial hypertension are necessary to guide appropriate therapy. This article discusses the diagnosis and treatment of this complex and multifactorial disease.

Evaluation of pulmonary arterial hypertension

PURPOSE OF REVIEW

Pulmonary arterial hypertension (PAH) is defined as a group of diseases characterized by a progressive increase of pulmonary vascular resistance leading to right ventricular failure and premature death. The purpose of this review is to analyze the current knowledge of the evaluation of PAH patients.

RECENT FINDINGS

Recently, the diagnostic approach has been more clearly defined according to the new clinical classification and with consensus reached on algorithms of various investigative tests and procedures that exclude other causes and ensure an accurate diagnosis of PAH. The diagnostic procedures include clinical history and physical examination, ECG, chest radiography, transthoracic Doppler echocardiography, pulmonary function tests, arterial blood gases, ventilation and perfusion lung scan, high-resolution CT of the lung, contrast-enhanced spiral CT of the lung and pulmonary angiography, blood tests and immunology, abdominal ultrasound scan, exercise capacity assessment, and hemodynamic evaluation.

SUMMARY

Invasive and noninvasive markers of disease severity, either biomarkers or physiologic parameters and tests that can be widely applied, have been proposed to reliably diagnose PAH and monitor the clinical course.

Prognosis of Pulmonary Arterial Hypertension*

Although idiopathic pulmonary arterial hypertension is perceived as a progressive disease with a uniformly poor outcome, the natural history of disease is heterogeneous, with some patients dying within months of diagnosis and others living for decades. The course of the disease has also been altered by advances in medical therapies. The outcome of patients with other types of pulmonary arterial hypertension (PAH) has been less well characterized. Assessment of prognosis of such patients is important, as it influences both medical therapy and referral for transplantation. This chapter will provide evidence based recommendations to assess the prognosis of patients with PAH.

Comparative analysis of clinical trials and evidence-based treatment algorithm in pulmonary arterial hypertension

The numerous controlled clinical trials performed recently in pulmonary arterial hypertension (PAH) can allow us to abandon a clinical-based treatment strategy and adopt an evidence-based therapy. Both uncontrolled and controlled clinical trials with different compounds and procedures are reviewed and compared in order to define the efficacy-to-side-effect ratio of each treatment. A grading system for the level of evidence of treatments based on the number of favorable controlled clinical trials performed with a given compound is adopted; a treatment algorithm based on the evidence derived by clinical trials is proposed. It includes drugs approved by regulatory agencies for the treatment of patients with PAH and/or drugs available on the market for other indications. The algorithm is restricted to patients in New York Heart Association (NYHA) functional class III or IV because they represent the largest population included in controlled clinical trials. In addition, the different treatments have been evaluated mainly in sporadic, idiopathic PAH and in PAH associated with scleroderma or to anorexigen use. Extrapolation of these recommendations to the other PAH subgroups should be done with caution. Oral anticoagulation is proposed for all patients, whereas diuretic treatment and supplemental oxygen are indicated in cases of fluid retention and hypoxemia, respectively. High doses of calcium channel blockers are indicated only in the minority of patients who are responders to acute vasoreactivity testing. Nonresponders to acute vasoreactivity testing, or responders who remain in NYHA functional class III, should be considered candidates for treatment with either an endothelin receptor antagonist or a prostanoid. Continuous intravenous administration of epoprostenol is proposed as rescue treatment in NYHA functional class IV patients. Phosphodiesterase-V inhibitors should be considered in patients who have failed or are not candidates to other therapies. Combination therapy can be attempted in selected cases. Both balloon atrial septostomy and lung transplantation are indicated for refractory patients or where medical treatment is unavailable.

Hemodynamic response to sildenafil, nitric oxide, and iloprost in primary pulmonary hypertension

STUDY OBJECTIVES

Different vasodilators and different routes of application are used for the treatment of primary pulmonary hypertension (PPH). Recently, sildenafil, a phosphodiesterase-V inhibitor, has been shown to have beneficial hemodynamic effects in PPH. However, the hemodynamic effects of sildenafil have not been characterized and compared to other vasodilators such as inhaled nitric oxide (iNO) or iloprost in PPH in the same group of patients.

STUDY DESIGN

We investigated prospectively 10 consecutive patients with PPH using iNO, iloprost aerosol, and oral sildenafil to test acute hemodynamic response during right-heart catheterization.

RESULTS

iNO, iloprost aerosol, and sildenafil caused a significant fall of mean pulmonary artery pressure and pulmonary vascular resistance (PVR) [p < 0.05]. Correspondingly, cardiac output and mixed venous saturation increased slightly in all groups. Systemic arterial pressure and vascular resistance were mainly unaltered. Using a PVR reduction of > or =20% to define a significant response, 7 of 10 patients were responders to iloprost aerosol, whereas 4 of 10 patients responded to iNO and oral sildenafil. Improvement of oxygenation as indicated by an increase of arterial oxygen tension was observed with iloprost aerosol (p < 0.01).

CONCLUSION

All of the three substances, iNO, iloprost aerosol, and oral sildenafil, significantly improved pulmonary hemodynamics in patients with PPH. The most prominent hemodynamic effects and improvement of oxygenation were observed with iloprost aerosol.

Clinical value of vasodilator test with inhaled nitric oxide for predicting long-term response to oral vasodilators in pulmonary hypertension

Acute vasodilator tests with prostacyclin (PGI2) or inhaled nitric oxide (iNO) are used to select patients with pulmonary arterial hypertension (PAH) who should be treated with oral vasodilators. The haemodynamic effects of PGI2 and iNO are different, and the limits for considering a vasodilator response as significant are controversial. The study was aimed to investigate the diagnostic performance of acute vasodilator testing with iNO and PGI2 in predicting the clinical outcome after 1 year treatment with oral vasodilators. Twenty-seven patients with severe PAH were studied. Nineteen patients were treated with oral vasodilators and their outcome after 1 year was qualified as favourable or unfavourable. The diagnostic performance of vasodilator tests in predicting this outcome was evaluated using receiver operating characteristics (ROC) curves. The acute effects of iNO and PGI2 on pulmonary artery pressure (PAP) were similar. By contrast, PGI2 produced more marked changes on cardiac output and pulmonary vascular resistance than iNO (P<0.05). The evolution at 1 year was favourable in 11 patients and unfavourable in 8. Patients with favourable evolution showed greater decrease of PAP with iNO than with PGI2 (P<0.05). The decrease of PAP with iNO had the greatest predictive value on the clinical outcome (area under ROC curve, 0.83). We conclude that in patients with PAH, acute vasodilator testing with iNO is preferable to PGI2 because it reflects more consistently the changes in pulmonary vascular tone. The acute decrease of PAP with iNO is the best predictor of the long-term response to oral vasodilator treatment.

Prevalence and outcome in systemic sclerosis associated pulmonary arterial hypertension: application of a registry approach

OBJECTIVE

To determine the prevalence of systemic sclerosis associated pulmonary arterial hypertension (SScPAH), evaluate outcome, and identify predictors of mortality in a large patient cohort.

METHODS

A prospective four year follow up study of 794 patients (722 from our own unit and 72 referrals). All patients screened for PAH using a combination of echocardiography, lung function testing, and clinical assessment. Patients with suspected raised pulmonary artery systolic pressures of >35 mm Hg, carbon monoxide transfer factor (TLCO) <50% predicted, or a precipitous fall in TLCO >20% over a one year period with no pulmonary fibrosis, and patients with SSc with breathlessness with no pulmonary fibrosis found were investigated with right heart catheterisation. All patients with SScPAH were treated in accordance with current best practice.

RESULTS

The prevalence of PAH was 12% (89/722) by right heart catheter. The survival was 81%, 63%, and 56% at 1, 2, and 3 years from the diagnosis (in 89 patients from our own cohort and 59/72 referrals). Haemodynamic indices of right ventricular failure--raised mRAP (hazard ratio 21), raised mPAP (hazard ratio 20), and low CI (hazard ratio 11) predicted an adverse outcome There was no significant difference in survival between patients with SScPAH with (n=40) and without (n=108) pulmonary fibrosis (p=0.3).

CONCLUSIONS

The prevalence of SScPAH in this cohort was similar to that of other catheter based studies and lower than that of previous echo based studies. The 148 patients with SScPAH actively treated had comparable outcomes to those of the cohorts with primary pulmonary hypertension. A high mRAP was the strongest haemodynamic predictor of mortality. To improve prognosis, future treatments need to be implemented at an earlier disease stage to prevent right ventricular decompensation.

Primary pulmonary hypertension: Current therapy

Because the causes of primary pulmonary hypertension (PPH) remains unknown, the therapeutic approach of the disease can be only empirical, based on the pathology and pathobiology of pulmonary circulation. Despite the inability to cure the disease, therapeutic advances over the past 20 years have contributed to an improvement of quality of life and prolonged survival in PPH patients. Current therapeutic approach of PPH mostly includes limitation of physical activity, long-term anticoagulation, and vasodilator therapy. Among all tested oral vasodilators, calcium-channel blockers are the most efficient long-term therapies by improving symptoms and hemodynamics in a subset of PPH patients (10% to 15%) who acutely respond to such drugs. Acute pulmonary vasodilator response to inhalation of nitric oxide can predict acute and chronic responses to oral calcium-channel blockers. A better understanding of the pathogenesis of PPH has changed the focus of medical treatments from purely chronic vasodilator therapy to the evaluation of agents, such as prostaglandins, that may reverse the proliferation of pulmonary vascular cells and result in regression of the pulmonary vascular hypertrophy and remodeling. Long-term treatment with intravenous epoprostenol (prostaglandin I(2) or prostacyclin) improves exercise capacity, hemodynamics and survival in most patients with PPH in functional class NYHA III or IV, and may be currently considered as the "gold standard" therapy for severe patients. However, response to long-term epoprostenol therapy may be incomplete, adverse effects are common, and survival remains unsatisfactory (55% at 5 years). In such patients with severe pulmonary hypertension refractory to medical therapy, atrioseptostomy and lung transplantation can be indicated.

[Clinico-hemodynamic study and treatment of 44 patients with primary pulmonary hypertension]

BACKGROUND

Primary pulmonary hypertension is a poorly understood disease with a difficult treatment.

PATIENTS AND METHOD

Retrospective study of a series of 44 patients suffering from pulmonary hypertension who were studied in our center between 1992 and 2000.

RESULTS

At diagnosis, 6 (13%) patients were classified as having NYHA functional class I, 11 (25%) had class II, 25 (57%) had class III, and 2 had class IV. Mean pulmonary artery systolic pressure by echo-doppler was 92 (range: 43-154) mmHg. Basal right catheterization showed a mean (SD) pulmonary artery pressure of 58 (18) mmHg, total basal pulmonary resistances of 1679 (1,071) din/cm2 and cardiac index of 2.2 (1) 1/minute/m2. Five patients improved with anticoagulation and calcium channel blockers therapy. Since 1998, 11 patients had been treated with continuous endovenous epoprostenol, yet only 3 (27%) had significant clinical improvement. Survival at 5 years after diagnosis was 56%. At the end of study, 7 (70%) out of 10 patients who underwent pulmonary transplantation were alive (mean: 34, range: 3-62 months).

CONCLUSIONS

Pulmonary hypertension is a disease with a poor prognosis. However, treatment with prostaglandins and pulmonary transplantation may lead to encouraging results.