The falling incidence of hematologic cancer after heart transplantation.

BACKGROUND: A number of changes in the management of heart transplantation (HT) patients have each tended to reduce the risk of post-HT hematologic cancer, but little information is available concerning the overall effect on incidence in the HT population. METHODS: Comparison of data from the Spanish Post-Heart-Transplantation Tumour Registry for the periods 1991-2000 and 2001-2010. RESULTS: The incidence among patients who underwent HT in the latter period was about half that observed in the former, with a particularly marked improvement in regard to incidence more than five yr post-HT. CONCLUSIONS: Changes in HT patient management have jointly reduced the risk of hematologic cancer in the Spanish HT population. Long-term risk appears to have benefited more than short-term risk.

Lung cancer after heart transplantation: results from a large multicenter registry.

In this study we analyzed Spanish Post-Heart-Transplant Tumour Registry data for adult heart transplantation (HT) patients since 1984. Median post-HT follow-up of 4357 patients was 6.7 years. Lung cancer (mainly squamous cell or adenocarcinoma) was diagnosed in 102 (14.0% of patients developing cancers) a mean 6.4 years post-HT. Incidence increased with age at HT from 149 per 100 000 person-years among under-45s to 542 among over-64s; was 4.6 times greater among men than women; and was four times greater among pre-HT smokers (2169 patients) than nonsmokers (2188). The incidence rates in age-at-diagnosis groups with more than one case were significantly greater than GLOBOCAN 2002 estimates for the general Spanish population, and comparison with published data on smoking and lung cancer in the general population suggests that this increase was not due to a greater prevalence of smokers or former smokers among HT patients. Curative surgery, performed in 21 of the 28 operable cases, increased Kaplan-Meier 2-year survival to 70% versus 16% among inoperable patients.

Predicting Short- and Long-Term Outcomes in Adult Heart Transplantation: Clinical Utility of MELD-XI Score.

BACKGROUND: Model for End-Stage Liver Disease scoring system excluding international normalized ratio (MELD-XI) has been related with worse outcomes after heart transplantation (HT). However, according to standards in prognostic models research, before implementing a risk score for daily clinical decision-making, its performance and impact on clinical practice/outcomes should be evaluated. The aim of this study was to evaluate the ability of the MELD-XI score to predict outcomes in daily clinical practice. MATERIAL AND METHODS: We retrospectively reviewed 190 consecutive adults undergoing HT between 2005-2015. Patients were stratified into low (MELD-XI <12) and high (MELD-XI ≥12) risk cohorts. Mortality rates at 30 days and 1 year were compared between MELD-XI groups. MELD-XI ability to predict 1-year mortality was assessed by the area under the receiver operating curve (AUC) and compared to that of bilirubin, creatinine, and pulmonary vascular resistance (PVR). RESULTS: Mortality rates at 30 days and 1 year were similar between groups (8% vs 13%; P = .28 and 21% vs 29%; P = .21, respectively). MELD-XI ability to predict 1-year mortality was poor and similar to that of bilirubin, creatinine, and PVR (0.51 vs 0.47 vs 0.50 vs 0.50, respectively). CONCLUSIONS: MELD-XI score utility in HT clinical decision-making is scarce since its discrimination ability is poor and similar to other simple prognostic variables.

Registro español de trasplante cardiaco. XXXIII informe oficial de la Asociación de Insuficiencia Cardiaca de la Sociedad Española de Cardiología / Spanish Heart Transplant Registry. 33rd official report of the Heart Failure Association of the Spanish Society of Cardiology

Introducción y objetivos Se actualizan los datos anuales de Registro español de trasplante cardiaco con los hallazgos de los procedimientos realizados en 2021. Métodos Se describen las principales características clínicas, del tratamiento recibido y de los resultados en términos de supervivencia del año 2021 y las tendencias en el periodo 2012-2020. Resultados En 2021 se han realizado 302 trasplantes cardiacos (un 8,6% más que el año anterior). En 2021 se ha confirmado la tendencia observada en años anteriores a una disminución de los trasplantes urgentes y a la realización de estos mayoritamente con dispositivos de asistencia ventricular. Las demás características y los resultados en términos de supervivencia muestran una clara tendencia a la estabilización en la última década. Respecto a 2019, en los años de la pandemia por SARS-CoV-2 (2020 y 2021) no se detecta un impacto relevante en los resultados en la fase aguda tras el trasplante y en la serie histórica. Conclusiones En 2021 se ha recuperado la actividad de trasplante hasta cifras previas a la pandemia por SARS-CoV-2, que no ha tenido un impacto global significativo en los resultados. Las características del procedimiento y los resultados muestran una clara tendencia a la estabilización en la última década (AU)

Introduction and objectives This report updates the annual data of the Spanish heart transplant registry with the procedures performed in 2021. Methods We describe the clinical profile, therapeutic characteristics and outcomes in terms of survival of the procedures performed in 2021. Their temporal trends are updated for the 2012 to 2020 period. Results In 2021, 302 heart transplants were performed (8.6% increase versus 2020). The tendency in 2021 confirmed that of prior years, with fewer urgent transplants and a preference for the use of ventricular assist devices. The remaining characteristics and survival showed a clear trend toward stability in the last decade. Compared with 2019, the SARS-CoV-2 pandemic (2020 and 2021) did not affect short- or long-term survival. Conclusions In 2021, transplant activity returned to prepandemic levels. The SARS-CoV-2 pandemic did not significantly affect transplant outcomes. The main transplant features and outcomes have clearly stabilized in the last decade (AU)

Impacto de la variabilidad intrapaciente en la concentración sanguínea de anticalcineurínicos en los resultados del trasplante cardiaco / Impact of intrapatient blood level variability of calcineurin inhibitors on heart transplant outcomes

Introducción y objetivos: El objetivo es estudiar el impacto clínico de la variabilidad intrapaciente (VIP) de la concentración sanguínea de los anticalcineurínicos en el trasplante cardiaco, pues la información actual es escasa. Métodos: Se analizó retrospectivamente a pacientes de edad≥18 años con un trasplante cardiaco realizado entre 2000 y 2014 y con supervivencia≥1 año. La VIP se valoró mediante el coeficiente de variación de concentraciones entre los meses 4 a 12 postrasplante. El compuesto de rechazo, mortalidad o pérdida del injerto y la mortalidad o pérdida del injerto 1-5 años tras el trasplante se analizaron mediante regresión de Cox. Resultados: Se estudió a 1.581 receptores (edad, 56 años; mujeres, 21%), tratados con ciclosporina (790 pacientes) o tacrolimus (791 pacientes). En el análisis multivariable, un coeficiente de variación> 27,8% tendió a asociarse con el compuesto de rechazo/mortalidad (HR=1,298; IC95%, 0,993-1,695; p=0,056) y con la mortalidad (HR=1,387; IC95%, 0,979-1,963; p=0,065) a los 5 años. La asociación con el rechazo fue significativa al analizar a la población sin rechazos durante el primer año del trasplante (HR=1,609; IC95%, 1,129-2,295; p=0,011). El tacrolimus tuvo menos VIP que la ciclosporina, junto con unos mejores resultados por la menor influencia de la VIP. Conclusiones: La VIP de los anticalcineurínicos, especialmente con la inmunosupresión basada en el tacrolimus, se asocia solo marginalmente con los resultados a medio plazo del trasplante cardiaco, aunque puede tener influencia en los pacientes más estables durante el primer año tras el trasplante (AU)

Introduction and objectives: Intrapatient blood level variability (IPV) of calcineurin inhibitors has been associated with poor outcomes in solid-organ transplant, but data for heart transplant are scarce. Our purpose was to ascertain the clinical impact of IPV in a multi-institutional cohort of heart transplant recipients. Methods: We retrospectively studied patients aged ≥18 years, with a first heart transplant performed between 2000 and 2014 and surviving≥ 1 year. IPV was assessed by the coefficient of variation of trough levels from posttransplant months 4 to 12. A composite of rejection or mortality/graft loss or rejection and all-cause mortality/graft loss between years 1 to 5 posttransplant were analyzed by Cox regression analysis. Results: The study group consisted of 1581 recipients (median age, 56 years; women, 21%). Cyclosporine immediate-release tacrolimus and prolonged-release tacrolimus were used in 790, 527 and 264 patients, respectively. On multivariable analysis, coefficient of variation> 27.8% showed a nonsignificant trend to association with 5-year rejection-free survival (HR, 1.298; 95%CI, 0.993-1.695; P=.056) and with 5-year mortality (HR, 1.387; 95%CI, 0.979-1.963; P=.065). Association with rejection became significant on analysis of only those patients without rejection episodes during the first year posttransplant (HR, 1.609; 95%CI, 1.129-2.295; P=.011). The tacrolimus-based formulation had less IPV than cyclosporine and better results with less influence of IPV. Conclusions: IPV of calcineurin inhibitors is only marginally associated with mid-term outcomes after heart transplant, particularly with the tacrolimus-based immunosuppression, although it could play a role in the most stable recipients (AU)

Consensus for improving the comprehensive care of patients with acute heart failure: summarised version.

The purpose of this consensus document was to reach an agreement among experts on the multidisciplinary care of patients with acute heart failure. Starting with a narrative review of the care provided to these patients and a critical analysis of the healthcare procedures, we identified potential shortcomings and improvements and formalised a document on recommendations for optimising the clinical and therapeutic approach for acute heart failure. This document was validated through an in-person group session guided using participatory techniques. The process resulted in a set of 36 recommendations formulated by experts of the Spanish Society of Cardiology, the Spanish Society of Internal Medicine and the Spanish Society of Urgent and Emergency Care. The recommendations are designed to optimise the healthcare challenge presented by the care of patients with acute heart failure in the context of Spain's current National Health System.

Right coronary artery-right atrium fistula in primary angiosarcoma of the heart.

We report a case of angiosarcoma of the heart, manifested as a continuous murmur. Right coronary arteriography disclosed a paracardiac mass with fistulas from the coronary vessel to the right atrium. Histologic study revealed this to be an angiosarcoma with sinusoidal pattern. To our knowledge, this is the first case of this kind of cardiac tumor presenting as a fistula from a coronary artery to the right atrium.

Spontaneous left atrial haematoma.

We present a woman with paroxysmal atrial fibrillation and a mass in the left atrium. Cross-sectional echocardiography defined the lesion as cystic, while magnetic resonance imaging depicted it as a solid mass with areas of focal bleeding. Surgical resection showed a partially organized haematoma within the left atrial wall. The patient did well after surgery, although atrial fibrillation recurred. The presence of an atrial haematoma is rare, specially when spontaneous, and we stress the usefulness of magnetic resonance in reaching an aetiologic diagnosis.

[An anomalous origin of the left coronary artery associated with a right coronary spasm as the cause of angina and presyncope]. / Origen anómalo de la arteria coronaria izquierda asociado a espasmo de la coronaria derecha como causa de angina y presíncope.

We describe the rare association of angina at effort and presyncope in a young patient with an anomalous origin of left coronary artery and associated coronary spasm in the normal right coronary artery. The patient did well under calcium channel blocker therapy after seven years of follow-up, which is in contrast with the usual recommended management of these patients.

[Pulmonary hypertension: current aspects]. / Hipertensión pulmonar: aspectos actuales.

Primary pulmonary hypertension, although less frequent than secondary forms, represents the true paradigm of this disease. The recent investigations on pulmonary vascular response mechanisms to different stimuli has increased our knowledge about the mechanism of high pulmonary pressure. Molecular biology of the endothelial cell has provided evidence that endothelial injury plus a genetic individual predisposition may be the pathogenic mainstream of this disease. The histologic findings of pulmonary hypertension are still a matter of controversy, although the clinical, epidemiological and prognostic features are better defined. Therapeutically, there has been important advances, specially with various vasodilators, like calciumantagonists, prostacyclin, adenosine and nitric oxide, as well as new routes of administration. In more advance stages of the disease, atrial septostomy (only paliative) and pulmonary or cardio-pulmonary transplantation, are other therapeutic options to consider, after an adequate selection of patients.

[Cardiomyopathies (VII). Natural history of hypertrophic cardiomyopathy]. / Miocardiopatías (VII). Historia natural de la miocardiopatía hipertrófica.

After a short historic review of conceptual developments in hypertrophic cardiomyopathy, the natural history of the disease is analyzed according to each of its morphologic and functional abnormalities. The lack of association between hypertrophic morphology and sudden death is considered. Diastolic dysfunction and LV obstruction, although a frequent cause of dyspnea and heart failure, is not a risk factor for sudden death. Something similar occurs with the infrequent appearance in this disease of contractile failure. Myocardial ischemia is frequent in hypertrophic cardiomyopathy and general prognostic information about it is still lacking. Nevertheless, in young patients with family history of sudden death, a positive Thallium effort test may be a marker of sudden death (without an arrhythmogenic substrate), and may respond to verapamil. Finally, the new knowledge about genetic mutations in hypertrophic cardiomyopathy are analized. We conclude with some futuristic comments about hypertrophic cardiomyopathy.

[The importance of determining oxygen consumption in the indications for a heart transplant]. / Importancia de la determinación del consumo de oxígeno en las indicaciones del trasplante cardíaco.

Maximal exercise performance in patients with chronic heart failure, as determined by peak oxygen consumption (VO2max.) during exercise testing has been shown to correlate well with mortality and its use as primary determining factor in the selection of patients for heart transplant has been advocated. Patients with a VO2max of less than 14 ml/kg/min appear at particularly high risk for mortality. Exercise performance can be influenced by a number of independent factors including subject motivation, peripheral deconditioning or other intrinsic abnormalities of skeletal muscle, and primary respiratory disease. It appears to be a precise gauge of functional impairment. VO2max can be used to accurately and reproducibly place an individual in a predefined functional class.

[Mycotic aneurysm caused by Aspergillus of the aortic suture line after heart transplantation]. / Aneurisma micótico por Aspergillus en la línea de sutura aórtica tras el trasplante cardíaco.

The first case of mycotic aneurysm of aorta by Aspergillus in a patient with heart transplantation is described, in which the infection was produced by direct surgical contamination of the aortic suture. The period of latency was of eight months. The unusualness of the case and its diagnostic difficulties, are is commented.

[Incidence and dynamic behavior of spontaneous echocardiographic contrast and atrial thrombi in the transplanted heart]. / Incidencia y comportamiento dinámico del contraste ecocardiográfico espontáneo y del trombo auricular en el corazón trasplantado.

BACKGROUND: Standard orthotopic heart transplantation produces important anatomic and functional atrial alterations with subsequent thrombotic risk. Therefore the aim of this study was to analyze the prevalence and evolution of spontaneous echocardiography, atrial thrombi and embolic events. PATIENTS AND METHOD: 52 consecutive transplanted patients were analyzed with transesophageal echocardiography and hemodynamic studies performed at 15 days and one year after transplantation. RESULTS: Spontaneous echocardiography contrast was present in 27 patients (52%). Ten atrial thrombi were observed (19.2%), 9 with spontaneous echocardiography contrast. Six atrial thrombi appeared on day 15 and 4 after one year (with spontaneous echocardiography contrast on the previous study). Using multiple logistic regression analysis left atrial size was the only independent predictor factor for spontaneous echocardiography contrast (OR = 1.27; 95% CI, 1.09-1.54) and was an important predictor factor of atrial thrombi formation (OR = 1.19; 95% CI, 1.04-1.42). Likewise, the main predictor of atrial thrombi was the presence of spontaneous echocardiography contrast (OR = 116; 95% CI, 8.4-999). The hemodynamic pattern did not predict either the presence of spontaneous echocardiography contrast or atrial thrombi. The global incidence of embolic events was 4% less than previously described. CONCLUSIONS: The incidence of atrial thrombi and spontaneous echocardiographic contrast after standard orthotopic heart transplantation was 19.2% and 52%, respectively. An enlarged atrium and/or spontaneous echocardiography contrast was found to increase the risk of atrial thrombi. Considering the dynamic nature of atrial thrombi formation, periodical transesophageal echocardiography studies are recommended after heart transplantation.

[Pulmonary arterial hypertension and heart transplantation: hemodynamic evolution and survival]. / Hipertensión arterial pulmonary y trasplante cardíaco: evolución hemodinámica y supervivencia.

BACKGROUND: Patients with chronic heart failure and pulmonary arterial hypertension are at risk of developing fatal right graft failure after transplantation, and there is no agreement about the limit of pulmonary vascular resistance for such risk. PURPOSE: To study what the impact is on the survival of a degree of pulmonary hypertension not considered to be an exclusion for orthotopic heart transplantation and to analyze the hemodynamic profile in the minor circuit after surgery. PATIENTS AND METHODS: We studied a group of 69 patients consecutively transplanted and with followup of at least one year. Patients were classified in two groups depending on the hemodynamic factors previous to transplant: group A (without pulmonary hypertension, 22 patients) and group B (with pulmonary hypertension, 47 patients). After heart transplantation we analyzed the causes of mortality and the evolution hemodynamic profile in both groups. RESULTS: In the group of patients with pulmonary hypertension there was an increase in perioperative mortality due to graft failure (p < 0.05), although at the end of the first year, the survival rate was similar in both groups. After heart transplantation, the level of pulmonary pressures dropped in the same group, but at the end of the first year, a 17% of the patients maintains some criteria of pulmonary hypertension. CONCLUSIONS: Our results confirm that degrees of pulmonary hypertension classically not considered as an exclusion for orthotopic heart transplantation were associated with an increase mortality by graft failure. The majority of survivors after heart transplantation normalize pulmonary pressures at one year of transplantation.

[Sildenafil as a substitute for subcutaneous prostacyclin in pulmonary hypertension]. / Sildenafilo como sustituto de prostaciclina subcutánea en la hepertensión pulmonar.

Subcutaneous prostacyclin (treprostinil) is an effective short-term treatment for pulmonary hypertension. The most frequently described adverse effect-pain in the area of injection-rarely requires that treatment be withdrawn. Sildenafil is a selective fosfodiesterase-5 inhibitor with pulmonary vasodilating effects. We describe the use of sildenafil as a substitute for treprostinil in a patient with pulmonary hypertension associated with lupus erythematosus. Treatment with treprostinil was discontinued due to uncontrollable abdominal pain.

Steroid withdrawal during 5 years following heart transplantation, and the relationship between steroid dosage at 1-year follow-up and complications during the next 2 years: results from the RESTCO study.

BACKGROUND: Little information is available regarding the controversial issue of steroid withdrawal following heart transplantation (HT), or instead in the incidence of adverse steroid effects at dosages typically employed in Spain. METHODS: We analyzed the 5-year follow-up records of 1209 patients (82.5% men, aged ≥ 18 years) who underwent HT between 2000 and 2005 and survived at least 1 month in 13 Spanish centers. The incidences of first steroid withdrawal before 1, 3, and 5 years post-HT were expressed as Kaplan-Meier probability estimates. Three patient groups defined in accordance with steroid dosage at 1-year follow-up (0, ≤ 5, and >5 mg/d; groups A, B, and C, respectively) were compared with regard to the incidence of de novo hypertension, diabetes, and bone fractures over the following 2 years. RESULTS: The 5-year incidence of withdrawal was 28%, 21% of whom required reintroduction of steroids. Kaplan-Meier probabilities of withdrawal before 1, 3, and 5 years post-HT were 8.8% (95% confidence interval ([CI] 7.3%-10.7%), 27.8% (CI 25.2%-30.6%), and 30.2% (CI 27.5%-33.2%), respectively. At 1-year follow-up, 9.9% of patients were steroid-free, 28.9% were taking ≤ 5 mg/d, and 61.3% >5 mg/d. The 2-year incidence of de novo hypertension increased significantly (P = .012) from 13.5% to 29.6% to 35.3% in groups A, B, and C respectively. These groups did not differ significantly in regard to the 2-year incidence of diabetes or bone fractures. CONCLUSIONS: Reintroduction of steroids was required by 21% of the 28% of Spanish HT patients who has been weaned from steroids within 5 years of HT. The incidence of de novo hypertension between 1 and 3 years post-HT increased with steroid dosage at 1-year follow-up. De novo diabetes and bone fractures showed no similar significant association.

Influence of steroid dosage, withdrawal, and reinstatement on survival after heart transplantation: results from the RESTCO study.

BACKGROUND: Little information is available regarding the consequences of steroid withdrawal following heart transplantation (HT) in Spain. METHODS: We analyzed the records of 1068 patients (81.6% men) who underwent HT between 2000 and 2005 in 13 Spanish centers who were aged ≥ 18 years and who survived at least 1 year. Death rates and Kaplan-Meier survival curves for 1 to 5 years post-HT were compared among four groups: groups A and B, patients on steroids throughout the first 5 years post-HT at dosages of ≤ 5 mg/d between 1-year and 5-year follow-up (group A; n = 148), or >5 mg/d for some part of this period (group B; n = 578). Groups C and D were patients from whom steroids were at some point withdrawn including group D (n = 73) with and group C (n = 269) without subsequent reintroduction into the maintenance regimen. RESULTS: Steroids were withdrawn at 1.6 ± 0.9 years post-HT in group C, and 1.7 ± 1.2 years post-HT in group D. The death rate between 1- and 5-year follow-up (deaths per 1000 person-years) was 44.3% (95% confidence interval 26.2-62.5) in group A, 42.6% (33.7-51.4) in group B, 30.5% (19.6-41.4) in group C, and 47.8% (21.8-73.7) in group D. There was no significant difference among them or among Kaplan-Meier survival curves of the four groups (P = .34 in both cases). Comparison of combined groups C + D with groups A + B showed no evidence of a greater mortality among combined groups C + D. CONCLUSIONS: The late withdrawal of steroids following HT was not associated with increased mortality.

The prognosis of noncutaneous, nonlymphomatous malignancy after heart transplantation: data from the Spanish Post-Heart Transplant Tumour Registry.

INTRODUCTION: Malignancy is a major complication in the management of solid organ transplant patients. Skin cancers show a better prognosis than other neoplasms, but not all others are equal: Ideally, patient management must take into account the natural history of each type of cancer in relation to the transplanted organs. We sought to determine the prognosis of various groups of noncutaneous nonlymphomatous (NCNL) cancers after heart transplantation (HT). METHODS: We retrospectively analyzed the records of the Spanish Post-Heart-Transplant Tumour Registry, which collects data on posttransplant tumors in all patients who have undergone HT in Spain since 1984. Data were included in the study up to December 2008. We considered only the first NCNL post-HT tumors. RESULTS: Of 4359 patients, 375 developed an NCNL cancer. The most frequent were cancers of the lung (n=97; 25.9%); gastrointestinal tract (n=52; 13.9%); prostate gland (n=47; 12.5%; 14.0% of men), bladder (n=32; 8.5%), liver (n=14; 3.7%), and pharynx (n=14; 3.7%), as well as Kaposi's sarcoma (n=11; 2.9%). The corresponding Kaplan-Meier survival curves differed significantly (P<.0001; log-rank test), with respective survival rates of 47%, 72%, 91%, 73%, 36%, 64%, and 73% at 1 year versus 26%, 62%, 89%, 56%, 21%, 64%, and 73% at 2 years; and 15%, 51%, 77%, 42%, 21%, 64%, and 52% at 5 years post-diagnosis, respectively. CONCLUSION: Mortality among HT patients with post-HT NCNL solid organ cancers was highest for cancers of the liver or lung (79%-85% at 5 years), and lowest for prostate cancer (23%).

Effect of different pharmacologic agents to reverse severe pulmonary hypertension among end-stage heart failure patients.

OBJECTIVE: The goal of this study was to analyze the hemodynamic responses during vasoreactivity tests among candidates for heart transplantation who displayed severe pulmonary hypertension seeking to identify risk markers of nonresponse to the test. MATERIALS AND METHODS: In this observational retrospective study we evaluated demographic, clinical, echocardiographic, and hemodynamic variables. The target hemodynamic goal in the vasoreactivity test was to achieve a transpulmonary gradient (TPG) <12 mm Hg and/or pulmonary vascular resistances (PVR) <2.5 Wood Units (WU). RESULTS: We analyzed medical records from 79 patients. Inotropes (dopamine or dobutamine) were used to treat 33 patients, nonselective vasodilators (nitroglycerin or sodium nitroprusside) were used in 22 patients, and prostacyclin (PC) was used in 24 patients. The study observed a significant decrease in pulmonary pressures, PVR, and TPG, with increased cardiac output (CO) compared with baseline hemodynamics in all groups. No significant differences were observed between agents except for an increase in CO, which was greater in the PC group. Also, 49.4% of patients were considered responders to the vasoreactivity test without significant differences between groups. Risk markers for absence of a response to the vasoreactivity test were a CO <2.5 L/min (odds ratio [OR] = 2.1; confidence interval [CI] 95%, 1.1-3.9; P = .035) and a PVR >6 WU (OR = 3.7; CI 95%, 1.8-7.6; P < .001) in the baseline hemodynamic study. CONCLUSIONS: Inotropes, nonselective vasodilators, and prostacyclin produced effective vasodilator responses in the pulmonary vascular bed during the vasoreactivity test. The presence of a baseline high PVR or a low CO were predictors of nonresponse to the test.