Hemolytic Anemia Associated Pulmonary Hypertension

Machado, Roberto F.; Gladwin, Mark T.

doi:10.1016/b978-1-4160-2246-6.50018-3

Cited by 5 publications

(10 citation statements)

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“…In β‐thalassemia patients, a threshold of 3.2 m/s is shown to have a high positive predictive value for the diagnosis of PH on RHC, though the positive predictive value of lower thresholds, such as 2.5 m/s, remains unknown . Thus, most experts suggest that a TRV greater than 3.0 m/s in thalassemia patients identifies a population at increased risk of PH who should undergo RHC . Most data regarding RHC in both TM and TI patients have been either case reports or small case series describing predominately precapillary PH with elevated mPAP in the setting of normal PAOP, yet cases of postcapillary PH related to left heart disease have also been described …”

Section: Clinical Presentation and Diagnosismentioning

confidence: 99%

Pulmonary hypertension associated with thalassemia syndromes

Fraidenburg

Machado

2016

Annals of the New York Academy of Sciences

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Chronic hemolytic anemia has increasingly been identified as an important risk factor for the development of pulmonary hypertension. Within the thalassemia syndromes, there are multiple mechanisms, both distinct and overlapping, by which pulmonary hypertension develops and that differ among β-thalassemia major or intermedia patients. Pulmonary hypertension in β-thalassemia major correlates with the severity of hemolysis, yet in patients whose disease is well treated with chronic transfusion therapy, the development of pulmonary hypertension can be related to cardiac dysfunction and the subsequent toxic effects of iron overload rather than hemolysis. β-thalassemia intermedia, on the other hand, has a higher incidence of pulmonary hypertension owing to the low level of hemolysis that exists over years without the requirement for frequent transfusions, while splenectomy is shown to play an important role in both types. Standard therapies such as chronic transfusion have been shown to mitigate pulmonary hypertension, and appropriate chelation therapy can avoid the toxic effects of iron overload, yet is not indicated in many patients. Limited evidence exists for the use of pulmonary vasodilators or other therapies, such as L-carnitine, to treat pulmonary hypertension associated with thalassemia. Here we review the most recent findings regarding the pathogenic mechanisms, epidemiology, presentation, diagnosis, and treatment of pulmonary hypertension in thalassemia syndromes.

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Section: Clinical Presentation and Diagnosismentioning

confidence: 99%

Pulmonary hypertension associated with thalassemia syndromes

Fraidenburg

Machado

2016

Annals of the New York Academy of Sciences

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“…PH is defined as a mean pulmonary artery pressure of ≥ 25 mmHg at rest or ≥ 30 mmHg during exercise, and can result from a wide range of conditions. It is a vascular disorder of the lung in which the pulmonary artery pressure rises above normal levels, compromises oxygenation and right‐heart function, and can ultimately become life‐threatening 15 . PH is a poorly understood, complex syndrome with many clinical phenotypes.…”

Section: Definition Of Pulmonary Hypertensionmentioning

confidence: 99%

“…An abnormally high tricuspid regurgitant jet velocity (TRV) > 2.5 m/sec measured by Doppler echocardiography is greater than two standard deviations above normal 12,15 . Using a TRV > 2.5 m/sec as a proxy for PH in patients clinically screened by echocardiography, evidence suggesting PH was found in 31% of patients with a measurable TRV, including 16% of the children evaluated in a recent analysis of the Thalassemia Clinical Research Network (TCRN) sponsored Thalassemia Longitudinal Cohort (TLC) 25 .…”

Section: Prevalence and Risk Factorsmentioning

confidence: 99%

“…Classic symptoms of PH like exertional dypsnea overlap with those of chronic anemia, often delaying clinical suspicion until late in the course of disease. In addition, the multiorgan complications of hemolytic anemia may limit exercise tolerance independent of elevations in pulmonary vascular resistance 15 . Asthma may also be a cofounding complication in hemolytic anemia 49,50 manifesting overlapping symptoms with PH that requires screening 50 .…”

Section: Clinical Presentationmentioning

confidence: 99%

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Pulmonary hypertension in thalassemia

Morris¹,

Vichinsky

2010

Annals of the New York Academy of Sciences

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Pulmonary hypertension (PH) is common in thalassemia and contributes to mortality. Advancing age and a history of splenectomy are major risk factors in this population. The etiology of PH is multifactorial, involving a complex interaction of platelets, the coagulation system, erythrocytes, and endothelial cells along with inflammatory and vascular mediators. The long-term effect of splenectomy, red cell membrane pathology, coagulation abnormalities, low nitric oxide (NO) bioavailability, excess arginase activity, platelet activation, oxidative stress, iron overload, and chronic hemolysis play a role. The process of hemolysis disables the arginine-NO pathway through the simultaneous release of erythrocyte arginase and cell-free hemoglobin. Both NO and its obligate substrate arginine are rapidly consumed. The biological consequences of hemolysis on NO bioavailability ultimately translate into the clinical manifestations of PH. Guidelines for the management of PH in thalassemia have not yet been established; however, clinical trials are ongoing in an effort to guide future therapy.

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“…We recommend and provide maximal SCD treatment with hydroxyurea therapy at maximum tolerated dose and judicious use of blood transfusion support, red cell growth factor support (in the setting of coexisting renal disease) and iron chelating agents where indicated. Specific therapy for pulmonary hypertension includes pulmonary vasodilators and antiremodeling agents [59] (Table 2). The key to the management of SCD and its complications includes early identification through screening, adequate patient education and counseling, prophylaxis therapy (childhood penicillin, vaccinations and folate supplementation where indicated), and the appropriate use of hydroxyurea.…”

Section: Managementmentioning

confidence: 99%

Sickle cell disease and pulmonary hypertension in Africa: A global perspective and review of epidemiology, pathophysiology, and management

et al. 2007

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Secondary pulmonary hypertension (PAH) has been shown to have a prevalence of 30% in patients with sickle cell disease (SCD) with mortality rates of 40% at 40 months after diagnosis in the United States. The burden of SCD is highest in sub-Saharan Africa, especially in Nigeria (West Africa), where approximately 6 million people are afflicted. The true global incidence, prevalence, and burden of SCD and its associated end organ complications however remain unknown. Chronic hemolysis represents a prominent mechanistic pathway in the pathogenesis of SCD-associated pulmonary hypertension via a nitric oxide (NO) scavenging and abrogation of NO salutatory effects on vascular function, including smooth muscle relaxation, downregulation of endothelial adhesion molecules and inhibition of platelet activation. Many known infectious risk factors for PAH are also hyperendemic in Africa, including Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS), chronic hepatitis B and C, and possibly malaria. Interactions between these infectious complications and SCD-related hemolysis could yield an even higher prevalence of pulmonary hypertension and compound the existing global health systems challenges in managing SCD. Indeed, our preliminary analysis of African immigrants currently in the United States suggests that pulmonary hypertension represents a significant complication of SCD in the African subcontinent. There is clearly a need to include Africa and other parts of the world with high SCD prevalence in future comprehensive studies on the epidemiology and treatment of end organ complications of an aging SCD population world-wide. Am.

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Hemolytic Anemia Associated Pulmonary Hypertension

Cited by 5 publications

References 129 publications

Pulmonary hypertension associated with thalassemia syndromes

Pulmonary hypertension associated with thalassemia syndromes

Pulmonary hypertension in thalassemia

Sickle cell disease and pulmonary hypertension in Africa: A global perspective and review of epidemiology, pathophysiology, and management

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