Lung and heart-lung transplant practice patterns in pulmonary hypertension centers

Double-lung versus heart-lung transplantation for end-stage cardiopulmonary disease: a systematic review and meta-analysis

We compared posttransplant outcomes following double-lung transplantation (DLTx) and heart-lung transplantation (HLTx), based on a search of PubMed, Cochrane Library, and Embase, from inception to March 8, 2022, for studies that report outcomes of these procedures. We then performed a meta-analysis of baseline characteristics and posttransplant outcomes. Subgroup analyses were implemented according to indication, publication year, and center. This study was registered on PROSPERO (number CRD42020223493). Ten studies were included in this meta-analysis, involving 1230 DLTx patients and 1022 HLTx patients. The DLTx group was characterized by older donors (P = 0.04) and a longer allograft ischemia time (P < 0.001) than the HLTx group. The two groups had comparable 1-year, 3-year, 5-year, 10-year survival rates (all P > 0.05), with similar results identified in subgroup analyses. We found no significant differences in 1-year, 5-year, and 10-year chronic lung allograft dysfunction (CLAD)-free survival, length of intensive care unit stay and hospital stay, length of postoperative ventilation, in-hospital mortality, or surgical complications between the groups (all P > 0.05). Thus, DLTx provides similar posttransplant survival to HLTx for end-stage cardiopulmonary disease. These two procedures have a comparable risk of CLAD and other posttransplant outcomes.

Advanced Circulatory Support and Lung Transplantation in Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a progressive fatal disease. Although medical therapies have improved the outlook for these patients, there still exists a cohort of patients with PAH who are refractory to these therapies. Lung transplantation (LT), and in certain cases heart-lung transplantation (HLT), is a therapeutic option for patients with severe PAH who are receiving optimal therapy yet declining. ECMO may serve as a bridge to transplant or recovery in appropriate patients. Although, the mortality within the first 3 months after transplant is higher in PAH recipients than the other indications for LT, and the long-term survival after LT is excellent for this group of individuals. In this review, we discuss the indications for LT in PAH patients, when to refer and list patients for LT, the indications for double lung transplant (DLT) versus HLT for PAH patients, types of advanced circulatory support for severe PAH, and short and long-term outcomes in transplant recipients with PAH.

Pulmonary Hypertension and Right Ventricular Failure: Lung Transplant Versus Heart-Lung Transplant

Pulmonary arterial hypertension is a highly morbid disease with limited treatment options that improve survival and currently the only curative treatment is transplantation. There is a small body of literature comparing the efficacy of lung and heart-lung transplantation in this population. The bulk of evidence suggests that most patients with severe right ventricular failure undergoing transplant will have recovery of right ventricular function after lung transplantation. Existing data suggest that, in the absence of complex congenital heart disease or significant left ventricular dysfunction, double-lung transplant is the surgical procedure of choice.

Heart-lung transplantation: current indications, prognosis and specific considerations

Heart-lung transplantation (HLTx) is currently the best treatment for patients who have end-stage heart and lung failure. Idiopathic pulmonary arterial hypertension (IPAH) was the main indication for HLTx in the 1980s. However, when studies showed resolution of right ventricular dysfunction after double-lung transplantation (DLTx), this last procedure became the preferred option for end-stage IPAH. Currently, the main indication of HLTx is congenital heart disease (CHD), followed by acquired heart disease combined with pulmonary hypertension and/or intrinsic lung disease. Although early posttransplant survival remains lower after HLTx than after lung transplantation, careful patient selection combined with surgical advances are producing improvements. Here, we review the practice patterns, trends, and outcomes of HLTx worldwide.

Cardiac Magnetic Resonance Evaluation of Left Ventricular Myocardial Strain in Pulmonary Hypertension

RATIONALE AND OBJECTIVES

We investigated the feasibility of detecting left ventricular (LV) cardiac magnetic resonance (CMR) strain abnormalities using feature-tracking in patients with pulmonary hypertension (PH).

MATERIALS AND METHODS

CMR was performed in 16 patients with all groups of PH and in 13 controls. Global and regional peak circumferential strains (%) (which have been shown to be robust by CMR), peak diastolic strain rate (%/s), and dyssynchrony index (ms) were quantified with feature-tracking software. Ventricular function and volumes were calculated from CMR, and right heart pressures were measured with catheterization.

RESULTS

Left ventricular ejection fraction (LVEF) was similar in patients (60.2% ± 11.0%) and controls (61.9% ± 4.5%), P = .150. Global LV peak circumferential strain was significantly different in patients compared to controls, -16.7 ± 2.8% vs -19.9 ± 1.8%, respectively (P = .001). The greatest difference in strain was seen in the LV septum, -11.6 ± 4.3% in patients vs -16.7 ± 4.0% in controls (P < .001). There was a significant association between septal strain and right ventricular end-diastolic volume index (P = .047) in patients with PH; however, there were no associations with pulmonary artery pressures or right ventricular ejection fraction.

CONCLUSIONS

Feature-tracking CMR can detect LV strain abnormalities in patients with PH and preserved or mildly depressed LVEF, with greatest abnormality in the septum. The association between septal strain and right ventricular end-diastolic volume index suggests that ventricular interdependence may be a mechanism of LV dysfunction in PH. Feature-tracking CMR may be useful for identification of LV dysfunction before LVEF significantly declines in patients with PH. The feasibility of detecting LV strain abnormalities in patients with PH shown by this study paves the way for a variety of future investigations into the applications of LV strain in this patient population.

Overview of Lung Transplantation, Heart-Lung Transplantation, Liver-Lung Transplantation, and Combined Hematopoietic Stem Cell Transplantation and Lung Transplantation

Lung transplantation (LTx) has evolved to represent the therapy of choice for many patients with end-stage lung diseases. Appropriate candidate selection for LTx is an important determinant of a positive outcome from transplantation. Posttransplantation survival has steadily improved, but long-term survival continues to be a challenge with a median survival of 5.8 years. Similarly, combined heart-lung transplantation and simultaneous liver-lung transplantation has been performed successfully in select patients who are not expected to survive either organ transplant alone. Moreover, LTx has been performed in patients who develop end-stage pulmonary complications following hematopoietic stem cell transplantation.

State of the Art of Combined Heart-Lung Transplantation for Advanced Cardiac and Pulmonary Dysfunction

Over the last several decades, significant advances and improvements in care of transplant patients have resulted in markedly improved outcomes. A number of options are available for patients with advanced cardiopulmonary dysfunction requiring transplantation. There is a debate about when isolated heart or isolated lung transplantation is no longer possible or advisable and combined heart-lung transplantation is justified. Organ availability and allocation severely limit the latter option to very few well-selected patients. We review practice patterns, trends, and outcomes after triple-organ heart-lung transplant (HLTx) worldwide, as well as our own experience with heart-lung transplant in the modern era.

Left and Right Ventricular Functional Dynamics Determined by Echocardiograms Before and After Lung Transplantation

Impaired cardiac function is considered a contraindication for lung transplantation (LT). Because right ventricular (RV) function is expected to improve after LT, poor left ventricular (LV) function is often the determinant for LT eligibility. However, the changes in cardiac function before and after LT have not yet been elucidated. Therefore, we reviewed echocardiograms obtained from 67 recipients before and after LT. In a subset of 49 patients, both RV and LV longitudinal strains based on 2-dimensional speckle tracking echocardiography were analyzed. The cardiopulmonary exercise tests were also reviewed. All patients showed significant improvements in their exercise capacity after LT. RV echo parameters improved in all patients after LT (RV fractional area change: 36.7 ± 5.6% to 41.5 ± 2.7%, RV strain: -15.5 ± 2.9% to -18.0 ± 2.1%, RV E/E': 8.4 ± 1.8 to 7.7 ± 1.8; all p <0.05). Overall, the left ventricular ejection fraction (LVEF) did not change (58.7 ± 6.0% to 57.5 ± 9.7%, p = 0.385); however, 20 patients (30%) showed >10% decrease in LVEF after LT (61.5 ± 6.1% to 47.3 ± 4.2%, p <0.001) and an increase in LV E/E' (11.8 ± 1.8 to 12.9 ± 2.2, p = 0.049). Multivariate logistic regression analysis revealed that pre-LT LV E/E' was associated with decrease in LVEF after LT (odds ratio 1.381, 95% confidence interval 1.010 to 1.947, p = 0.043). Furthermore, patients with strain data showed that lower pre-LT LV strain was independently associated with LVEF decrease after LT (odds ratio 1.293, 95% confidence interval 1.088 to 1.614, p = 0.002). Although RV function improves after LT, LV systolic and diastolic functions deteriorate in a sizable proportion of patients. Impaired LV diastolic function before transplant appears to increase the risk of LVEF deterioration after LT.

Should we perform bilateral-lung or heart–lung transplantation for patients with pulmonary hypertension?

A best evidence topic was constructed according to a structured protocol. The following question was addressed: of the following two procedures, heart–lung transplantation or bilateral-lung transplantation (BLTx), which offers the best outcome for patients with pulmonary hypertension (PH) listed for thoracic transplantation? Of the 77 papers found using a report search for PH and thoracic transplantation, 9 represented the best evidence to answer this clinical question. Overall, 1189 (67%) lung transplantations and 578 (33%) heart–lung transplantations have been reported worldwide for idiopathic PH. For patients with Eisenmenger's syndrome, HLTx represents up to 70% of the transplantation procedures they undergo. On the whole, neither procedure demonstrated an overall survival benefit, when compared with the other. However, PH patients represent a heterogeneous population according to (i) the primary mechanism of PH and (ii) the consequences of PH on right or/and left heart function. With regard to the latter consideration, the current evidence shows that HLTx offers excellent functional and survival outcomes for patients with congenital heart disease and Eisenmenger's syndrome, severe right or/and left heart dysfunction, and who are chronically inotropic dependent. As far as heart dysfunction is concerned, the published evidence approximated cut-off values at 10–25% for the right ventricle ejection fraction (RVEF) and at 32–55% for the left ventricle ejection fraction (LVEF). In the case of lower values for RVEF and LVEF, HLTx should be performed. In all other patients with PH, the evidence demonstrated that BLTx offers a comparable outcome with the advantage of better organ sharing for other recipients. In order to reduce the waiting time on transplantation lists, cardiac repair and BLTx can be offered in experienced centres to patients with simple cardiac anomalies such as atrial septal defect, patent ductus arteriosus or perimembranous ventricular septal defect.

Lung transplantation and atrial septostomy in pulmonary arterial hypertension

This article summarizes the current literature regarding surgical interventions in pulmonary hypertension, excluding chronic thromboembolic pulmonary hypertension. The article discusses the use of atrial septostomy in patients meeting criteria as well as single, double, and heart-lung transplantation.

Pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a chronic and progressive disease leading to right heart failure and ultimately death if untreated. The first classification of PH was proposed in 1973. In 2008, the fourth World Symposium on PH held in Dana Point (California, USA) revised previous classifications. Currently, PH is devided into five subgroups. Group 1 includes patients suffering from idiopathic or familial PAH with or without germline mutations. Patients with a diagnosis of PAH should systematically been screened regarding to underlying mutations of BMPR2 gene (bone morphogenetic protein receptor type 2) or more rarely of ACVRL1 (activine receptor-like kinase type 1), ENG (endogline) or Smad8 genes. Pulmonary veno occusive disease and pulmonary capillary hemagiomatosis are individualized and designated as clinical group 1'. Group 2 'Pulmonary hypertension due to left heart diseases' is divided into three sub-groups: systolic dysfonction, diastolic dysfonction and valvular dysfonction. Group 3 'Pulmonary hypertension due to respiratory diseases' includes a heterogenous subgroup of respiratory diseases like PH due to pulmonary fibrosis, COPD, lung emphysema or interstitial lung disease for exemple. Group 4 includes chronic thromboembolic pulmonary hypertension without any distinction of proximal or distal forms. Group 5 regroup PH patients with unclear multifactorial mechanisms. Invasive hemodynamic assessment with right heart catheterization is requested to confirm the definite diagnosis of PH showing a resting mean pulmonary artery pressure (mPAP) of ≥ 25 mmHg and a normal pulmonary capillary wedge pressure (PCWP) of ≤ 15 mmHg. The assessment of PCWP may allow the distinction between pre-capillary and post-capillary PH (PCWP > 15 mmHg). Echocardiography is an important tool in the management of patients with underlying suspicion of PH. The European Society of Cardiology and the European Respiratory Society (ESC-ERS) guidelines specify its role, essentially in the screening proposing criteria for estimating the presence of PH mainly based on tricuspid regurgitation peak velocity and systolic artery pressure (sPAP). The therapy of PAH consists of non-specific drugs including oral anticoagulation and diuretics as well as PAH specific therapy. Diuretics are one of the most important treatment in the setting of PH because right heart failure leads to fluid retention, hepatic congestion, ascites and peripheral edema. Current recommendations propose oral anticoagulation aiming for targeting an International Normalized Ratio (INR) between 1.5-2.5. Target INR for patients displaying chronic thromboembolic PH is between 2–3. Better understanding in pathophysiological mechanisms of PH over the past quarter of a century has led to the development of medical therapeutics, even though no cure for PAH exists. Several specific therapeutic agents were developed for the medical management of PAH including prostanoids (epoprostenol, trepoprostenil, iloprost), endothelin receptor antagonists (bosentan, ambrisentan) and phosphodiesterase type 5 inhibitors (sildenafil, tadalafil). This review discusses the current state of art regarding to epidemiologic aspects of PH, diagnostic approaches and the current classification of PH. In addition, currently available specific PAH therapy is discussed as well as future treatments.

Current pathophysiological concepts and management of pulmonary hypertension

Pulmonary hypertension (PH), increasingly recognized as a major health burden, remains underdiagnosed due mainly to the unspecific symptoms. Pulmonary arterial hypertension (PAH) has been extensively investigated. Pathophysiological knowledge derives mostly from experimental models. Paradoxically, common non-PAH PH forms remain largely unexplored. Drugs targeting lung vascular tonus became available during the last two decades, notwithstanding the disease progresses in many patients. The aim of this review is to summarize recent advances in epidemiology, pathophysiology and management with particular focus on associated myocardial and systemic compromise and experimental therapeutic possibilities. PAH, currently viewed as a panvasculopathy, is due to a crosstalk between endothelial and smooth muscle cells, inflammatory activation and altered subcellular pathways. Cardiac cachexia and right ventricular compromise are fundamental determinants of PH prognosis. Combined vasodilator therapy is already mainstay for refractory cases, but drugs directed at these new pathophysiological pathways may constitute a significant advance.

Surgical Treatment of Pulmonary Arterial Hypertension

Significant advances in the treatment of pulmonary arterial hypertension have occurred in the last several years. The decision to refer a patient for transplantation requires a dynamic approach. Candidate selection and timing of referral to transplant centers is critical for success, particularly with current allocation protocols that do not take into account the severity of illness. Though long-term success is tempered by chronic allograft dysfunction and infection, considerable improvements in outcomes have established lung transplantation for pulmonary arterial hypertension as an efficacious and life-prolonging treatment. However, transplantation should be reserved for patients who have failed the best available medical therapy. Ideally, transplantation occurs when the clinically deteriorating patient has enough reserve to survive long enough to be transplanted but is not debilitated enough to jeopardize the graft. There is significant uncertainty with regard to this ideal.

Evaluating health-related quality of life, work ability, and disability in pulmonary arterial hypertension: an unmet need

To our knowledge, there are no specific and validated measures of quality of life (QoL) or degree of disability for pulmonary arterial hypertension (PAH). A review of the literature shows that, with the exception of one recently designed specifically for pulmonary hypertension, QoL questionnaires used in PAH studies are generic measures. These are selected because of shared symptoms that do not necessarily correlate well with functional or physiologic measures and have not been validated for applicability in PAH. In this review, we present the available QoL tools for pulmonary artery hypertension and describe the need for more specific instruments that consider the physical and emotional implications of the diseases associated with PAH and the impact of various treatment options. We also discuss the impact of PAH on work ability and the need for provisions to address medical disability status and Social Security benefit status.

Time course and mechanisms of left ventricular systolic and diastolic dysfunction in monocrotaline-induced pulmonary hypertension

Although pulmonary hypertension (PH) selectively overloads the right ventricle (RV), neuroendocrine activation and intrinsic myocardial dysfunction have been described in the left ventricle (LV). In order to establish the timing of LV dysfunction development in PH and to clarify underlying molecular changes, Wistar rats were studied 4 and 6 weeks after subcutaneous injection of monocrotaline (MCT) 60 mg/kg (MCT-4, n = 11; MCT-6, n = 11) or vehicle (Ctrl-4, n = 11; Ctrl-6, n = 11). Acute single beat stepwise increases of systolic pressure were performed from baseline to isovolumetric (LVPiso). This hemodynamic stress was used to detect early changes in LV performance. Neurohumoral activation was evaluated by measuring angiotensin-converting enzyme (ACE) and endothelin-1 (ET-1) LV mRNA levels. Cardiomyocyte apoptosis was evaluated by TUNEL assay. Extracellular matrix composition was evaluated by tenascin-C mRNA levels and interstitial collagen content. Myosin heavy chain (MHC) composition of the LV was studied by protein quantification. MCT treatment increased RV pressures and RV/LV weight ratio, without changing LV end-diastolic pressures or dimensions. Baseline LV dysfunction were present only in MCT-6 rats. Afterload elevations prolonged tau and upward-shifted end-diastolic pressure dimension relations in MCT-4 and even more in MCT-6. MHC-isoform switch, ACE upregulation and cardiomyocyte apoptosis were present in both MCT groups. Rats with severe PH develop LV dysfunction associated with ET-1 and tenascin-C overexpression. Diastolic dysfunction, however, could be elicited at earlier stages in response to hemodynamic stress, when only LV molecular changes, such as MHC isoform switch, ACE upregulation, and myocardial apoptosis were present.

Review: Therapeutic advances in pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, in situ thrombosis, and vascular remodeling of small pulmonary arteries inducing increased pulmonary arterial resistance. Conventional treatment is based on life style modification and nonspecific treatment (warfarine, diuretics, oxygen). Calcium channel blockers are vasodilatators that have been shown to be of great efficacy in a very specific subpopulation of patients with PAH. For the majority of patients, specific PAH therapies are still lacking. Numerous studies evaluating prostacyclin agonists, endothelin-receptor antagonists, and phosphodiesterase type 5 inhibitors are now available to guide therapeutic choices. Despite those important advances there is still no cure for PAH. Fortunately, research is ongoing and many drugs show promises.

Pulmonary hypertension in the critical care setting: classification, pathophysiology, diagnosis, and management

Pulmonary hypertension (PH) is common in the critical care setting, and may be a target for specific therapy. Moderate degrees of pulmonary hypertension are most often the consequence of acute or chronic heart failure, hypoxemia, or acute pulmonary embolism, and may be relatively rapidly reversible. The consequences of more severe forms of PH, both acute and chronic, can include hypotension; low cardiac output; right heart failure with congestion of the liver, gut, and kidneys; and varying degrees of hypoxemia, each of which can lead to death or severe disability. We review the physiology, definitions, classification, pathogenesis, diagnostic tools, and algorithms for diagnosis and specific treatments for the various causes of PH as seen in the critical care setting.

Surgical patient outcomes after the increased use of bilateral lung transplantation

OBJECTIVES

Despite the potential limitation of organ availability, several surgical groups have advocated preferential bilateral lung transplantation because of its demonstrated long-term survival advantage. Comparative results for single and sequential double lung transplantation performed at a single center are evaluated to determine whether such a policy improves patient outcome.

METHODS

A retrospective analysis of demographic and outcome data for patients undergoing lung transplantation was performed. Patients were grouped as single or double lung recipients and segregated into diagnostic categories according to the lung allocation scoring system. Era terciles were chosen on the basis of year of transplant, operating surgeon, and transplant volume.

RESULTS

Between November 1990 and September 2005, 344 lung transplant procedures were performed in 339 patients. Over three time periods evaluated, the proportion of patients undergoing double lung transplant procedures increased. Overall survivals at 3 months and 1, 3, and 5 years were 89%, 79%, 60%, and 52%, respectively. After adjusting for lung recipient characteristics, survival after double lung transplantation was improved when compared with single lung transplantation (P = .020). Overall patient survival among the three time periods was not significantly different at 30 days and 1 and 3 years despite increasing maximal donor organ ischemia times.

CONCLUSIONS

In this single-center study, despite longer median allograft ischemic times, as well as greater patient acuity as determined by listing diagnosis, overall early and midterm patient survival has remained higher than nationally reported figures. Bilateral lung transplantation in eligible patients is the procedure of choice.

Pulmonary arterial hypertension

Better recognition of primary pulmonary hypertension can produce better treatment by comprehensive therapists.

Surrogate markers for adverse outcomes in normotensive patients with pulmonary embolism*

BACKGROUND

Although echocardiography has proven utility in risk stratifying normotensive patients with pulmonary embolism, echocardiography is not always available.

OBJECTIVE

Test if a novel panel consisting of pulse oximetry, 12-lead electrocardiography, and serum troponin T would have prognostic equivalence to echocardiography and to examine the prognostic performance of age, previous cardiopulmonary disease, D-dimer, brain natriuretic peptide, and percentage of pulmonary vascular occlusion on chest computed tomography.

DESIGN

Prospective cohort study.

PATIENTS AND SETTING

Normotensive (systolic blood pressure of >100 mm Hg) emergency department and hospital inpatients with diagnosed pulmonary embolism who underwent cardiologist-interpreted echocardiography and other measurements within 15 hrs of anticoagulation.

MEASUREMENTS AND MAIN RESULTS

End points were in-hospital circulatory shock or intubation, or death, recurrent pulmonary embolism, or severe cardiopulmonary disability (defined as echocardiographic evidence of severe right ventricular dysfunction with New York Heart Association class III dyspnea or 6-min walk test of <330 m) at 6-month follow-up. The two-one-sided test tested the hypothesis of equivalence with one-tailed alpha = 0.05 and Delta = 5%. Of 200 patients enrolled, data were complete for 181 (88%); 51 of 181 patients (28%) had an adverse outcome, including in-hospital complication (n = 18), death (n = 11), recurrent pulmonary embolism (n = 2), or cardiopulmonary disability (n = 20). Right ventricular dysfunction on initial echocardiogram was 61% sensitive (95% confidence interval, 46-74%) and 57% specific (48-66%). The panel was 71% sensitive (56-83%) and 62% specific (53-71%). The two-one-sided procedure demonstrated superiority of the panel to echocardiography for both sensitivity and noninferiority for specificity. No other biomarker demonstrated equivalence, noninferiority, or superiority for sensitivity and specificity.

CONCLUSION

Normotensive patients with pulmonary embolism have a high rate of severe adverse outcomes during 6-month follow-up. A panel of three widely available tests can be used to risk stratify patients with pulmonary embolism when formal echocardiography is not available.

Myocardial dysfunction and neurohumoral activation without remodeling in left ventricle of monocrotaline-induced pulmonary hypertensive rats

In monocrotaline (MCT)-induced pulmonary hypertension (PH), only the right ventricle (RV) endures overload, but both ventricles are exposed to enhanced neuroendocrine stimulation. To assess whether in long-standing PH the left ventricular (LV) myocardium molecular/contractile phenotype can be disturbed, we evaluated myocardial function, histology, and gene expression of autocrine/paracrine systems in rats with severe PH 6 wk after subcutaneous injection of 60 mg/kg MCT. The overloaded RV underwent myocardial hypertrophy ( P < 0.001) and fibrosis ( P = 0.014) as well as increased expression of angiotensin-converting enzyme (ACE) (8-fold; P < 0.001), endothelin-1 (ET-1) (6-fold; P < 0.001), and type B natriuretic peptide (BNP) (15-fold; P < 0.001). Despite the similar upregulation of ET-1 (8-fold; P < 0.001) and overexpression of ACE (4-fold; P < 0.001) without BNP elevation, the nonoverloaded LV myocardium was neither hypertrophic nor fibrotic. LV indexes of contractility ( P < 0.001) and relaxation ( P = 0.03) were abnormal, however, and LV muscle strips from MCT-treated compared with sham rats presented negative ( P = 0.003) force-frequency relationships (FFR). Despite higher ET-1 production, BQ-123 (ETA antagonist) did not alter LV MCT-treated muscle strip contractility distinctly ( P = 0.005) from the negative inotropic effect exerted on shams. Chronic daily therapy with 250 mg/kg bosentan (dual endothelin receptor antagonist) after MCT injection not only attenuated RV hypertrophy and local neuroendocrine activation but also completely reverted FFR of LV muscle strips to positive values. In conclusion, the LV myocardium is altered in advanced MCT-induced PH, undergoing neuroendocrine activation and contractile dysfunction in the absence of hypertrophy or fibrosis. Neuroendocrine mediators, particularly ET-1, may participate in this functional deterioration.

Management of heart failure with pulmonary hypertension

Heart failure (HF) and pulmonary hypertension (PH) coexist frequently and contribute to each other. Because PH often is an insidious disease, the cornerstone of management is the early identification and treatment of its underlying causes, such as left-sided heart disease, left to right shunts, and pulmonary disorders. A practical clinical classification has been proposed by the Third World Symposium on Pulmonary Arterial Hypertension for the purpose of diagnosis and treatment of PH. Thromboembolic pulmonary hypertension should always be considered. Recent studies using vasodilators such as prostacyclins and endothelin antagonists give new hope in the otherwise poor prognosis of idiopathic pulmonary arterial hypertension and its related conditions. Despite optimum medical management, transplantation (lung/heart-lung) remains the choice in severely symptomatic patients.

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.

Traitement de l’hypertension artérielle pulmonaire

Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, in situ thrombosis, and vascular remodeling of small pulmonary arteries. It induces a fixed pulmonary arterial obstruction, persistent elevation of pulmonary arterial resistance, and eventually right heart failure. Conventional therapy is based on simple measures (exercise limitation) and nonspecific treatments (warfarin, diuretics, and oxygen). Pure vasodilators, such as calcium channel blockers, are effective only in a minority of patients who have an acute response to vasodilator testing. Intravenous prostacyclin (epoprostenol) and endothelin receptor blockers have vasodilator and antiproliferative properties. Epoprostenol therapy has significantly improved PAH prognosis and remains the first-line treatment for patients with the most severe disease. Bosentan is an interesting first-line treatment for NYHA functional class III patients. Availability of novel specific drugs (endothelin receptor type A antagonists, prostacyclin analogues, type 5 phosphodiesterase inhibitors) is opening new perspectives in PAH treatment. The long-term benefit of these drugs remains to be evaluated and their respective place in treatment of these patients is still uncertain. The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.

Hypertension artérielle pulmonaire

INTRODUCTION

Pulmonary arterial hypertension (PAH) is a rare condition characterised by progressively elevated pulmonary arterial resistance leading to right heart failure.

STATE OF THE ART

A recent classification distinguishes idiopathic PAH, familial PAH and PAH secondary to other conditions (connective tissue disease, congenital heart disease, portal hypertension, human immunodeficiency virus infection or appetite suppressant exposure). Echocardiography is the initial investigation of choice for non-invasive detection of PAH but measurement of pulmonary pressures and cardiac output during right-heart catheterization are necessary to confirm the diagnosis of PAH. Conventional treatment includes non-specific drugs (warfarin, diuretics, oxygen). Intravenous epoprostenol is the first-line treatment for the most severely affected patients. In less severe cases, the first-line treatment may include bosentan or a prostacyclin analogue.

PERSPECTIVES AND CONCLUSIONS

Recent advances in the management of PAH have markedly improved prognosis. The avai-lability of novel specific drugs including type 5 phosphodiesterase inhibitors offers novel therapeutic perspectives but their exact role in the treatment of PAH is still uncertain. The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.

Severe Left Ventricular Dysfunction Secondary to Primary Pulmonary Hypertension: Bridging Therapy With Bosentan Before Lung Transplantation

When right ventricular failure develops secondary to primary pulmonary hypertension, right-left ventricular interaction may lead to severe impairment of left ventricular function. In such cases, many experts favor combined heart-lung transplantation by fear that the left ventricle may not recover after transplantation of the lungs alone. We report a case of primary pulmonary hypertension with severely diminished right and left ventricular function. The patient was rendered amenable to isolated pulmonary transplantation with the endothelin-receptor antagonist bosentan. The medication improved right and left ventricular function to the point that heart transplantation no longer appeared necessary. After double-lung transplantation the patient's cardiac function made a full recovery. This approach might be particularly welcome considering both the current donor organ shortage and the limited number of surgical teams with expertise in heart-lung transplantation.

[Treatments for pulmonary arterial hypertension]

PURPOSE

Pulmonary arterial hypertension (PAH) is characterized by vasoconstriction, in situ thrombosis and vascular remodeling of small pulmonary arteries inducing a fixed pulmonary arterial obstruction and persistent elevation of pulmonary arterial resistance. Conventional treatment is based on simple measures (exercise limitation) and non-specific drugs (warfarine, diuretics, oxygen).

CURRENT KNOWLEDGE AND KEY POINTS

Pure vasodilators like calcium channel antagonists have little or no effect on the vast majority of patients, presumably because fixed pulmonary arteriopathy predominate over vasoconstriction. Intravenous prostacyclin (epoprostenol) and endothelin receptor antagonists have vasodilator and antiproliferative properties. Epoprostenol therapy has resulted in significant improvements in prognosis of this disease and this drug remains the first-line treatment of the most severe patients. Bosentan is an interesting first-line treatment for NYHA functional class III patients. Availability of novel specific drugs (endothelin receptor type A antagonists, prostacyclin analogues, type 5 phosphodiesterase inhibitors) open new perspectives in treatment of PAH. The long-term benefit of these drugs remains to be evaluated and their respective place in treatment of these patients is still uncertain. We here present the different therapeutic alternatives available in the PAH and propose an algorithm for treatment of these patients.

FUTURE PROSPECTS AND PROJECTS

The evolution of therapy from vasodilators to antiproliferative agents reflects the advancement in our understanding of the mechanisms mediating pulmonary arterial hypertension.

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.

Cardiopulmonary transplantation: experience of a lung transplant group

Cardiopulmonary transplantation (CPT) is indicated for patients eligible for heart transplantation (HT) or lung transplantation (LT) who have severe concomitant lung or heart disease. Only 2 groups perform CPT in Spain. We report our experience with 18 CPTs representing 8.2% and 5% compared with LT (220) and HT (362), respectively, from February 13, 1990 to October 15, 2002. The mean time on a waiting list was 138 days. The current number of surviving patients is 7 (39%), with a mean follow-up of 602 days (range, 3 to 4627 days). They all remain asymptomatic with normal respiratory function in 4 patients. No cardiac graft rejection has been detected. Two patients experienced sustained gastroparesis during the first year with spontaneous resolution. Death occurred within the first 3 months in 9 patients. These outcomes contrast with the early mortality associated with LT and HT in our series, namely 10.6% and 11%, respectively. The different causes of death were as follows: sepsis and multiorgan failure in 5 patients, hemorrhagic shock in 3 patients, and suture dehiscence and fungal aortic perforation in 1 patient. Late mortalities were recorded in 2 cases. Overall patient survival in our series is lower than that reported by the International Registry (IR), with an early mortality rate of 50% (30% IR). Nevertheless, our survival rate at 10 years after transplantation is 30% (26% IR). We conclude that CPT should be considered despite the greater early morbidity and mortality.

Long-term results of cardiac transplantation from live donors: the domino heart transplant

BACKGROUND

Hearts explanted from the recipients of heart-lung transplants provide a unique source of transplants from live donors. This article presents long-term results with this procedure at our center.

METHODS

We performed a retrospective chart review of domino transplantations performed in our institution between 1989 and 1998.

RESULTS

We analyzed 131 domino transplants (123 orthotopic, 8 heterotopic). Domino hearts were from patients with cystic fibrosis (69%), primary pulmonary hypertension (15%), and other diagnoses (16%). The mean recipient pulmonary vascular resistance (PVR) was 3.1 Wood units, 25% of patients having values >4 Wood units. Thirty-day mortality was 13%. The 1-, 5-, and 10-year graft survival was 75% (70% confidence interval [CI], 65-74), 70% (70% CI, 65-74), and 58% (70% CI, 52-64), respectively. Patients with PVR >4 Wood units had 1-year survival (76%; 70% CI, 69-84) similar to that of patients with PVR of < or =4 units (74%; 70% CI, 69-80). Recipients of hearts from patients with cystic fibrosis survived longer (5-year survival, 76%; 70% CI, 71-82) vs 65% for non-cystic fibrosis hearts (70% CI, 57-74) p = 0.09). One-year survival was decreased after transplantation of hearts from female donors (66%; 70% CI, 60-72)) compared with hearts from male donors (85%; 70% CI, 79-90); p = 0.06). Late deaths caused by coronary artery disease and malignancy were uncommon.

CONCLUSION

Although the rate of early mortality after domino transplantation was slightly higher than after cadaveric transplantation, we noted a remarkably low long-term attrition rate in recipients of domino grafts, up to 10 years. In addition, successful transplantation of patients with high PVR supports the hypothesis that heart-lung recipients may provide superior donor hearts for this patient group, many of whom traditional listing criteria would exclude.

Pulmonary arterial hypertension in congenital heart disease

Pulmonary arterial hypertension (PAH) is a recognized complication of congenital systemic to pulmonary arterial cardiac shunts. The prognosis of PAH in this situation is better than primary or other secondary forms of PAH. Our knowledge of the pathophysiology of PAH complicating congenital heart disease has evolved over the past decade. Despite differences in etiology and pathobiology, therapies that have proven successful for primary PAH may benefit this group of patients.