Pulmonary hypertension is a common complication of sickle cell anemia. Despite the fact that the elevations in pulmonary artery pressures are slight, morbidity and mortality are high. In adult sickle cell anemia patients, pulmonary hypertension is emerging as a major risk factor for death. The pathogenesis of sickle cell anemia-related pulmonary hypertension is multifactorial, including hemolysis, impaired nitric oxide bioavailability, chronic hypoxemia, thromboembolism, chronic liver disease and asplenia. In the majority of patients, pulmonary arterial hypertension is the main cause of elevated pulmonary artery pressures. However, pulmonary venous hypertension also plays a role in a subgroup of patients. Specific data on the effects of treatment modalities for pulmonary hypertension in patients with sickle cell anemia are scarce. It is likely that all patients would benefit from maximization of sickle cell anemia therapy, and that patients with the severe form of the disease would benefit from treatment with selective pulmonary vasodilators and antiproliferative agents. Large trials evaluating the effects of treatment for pulmonary hypertension in the sickle cell anemia population are underway.

Keywords: Anemia, Sickle cell; Hemolysis; Hypertension, pulmonary; Nitric oxide.

Recent studies have suggested an association between pulmonary arterial hypertension (PAH) and thyroid diseases (hypothyroidism and hyperthyroidism). This combination has a good prognosis, because the increase in the pulmonary artery pressure is usually slight and reverses after the treatment of the thyroid disease. Although the exact mechanism involved in the pathogenesis of this combination has not yet been established, it has been hypothesized that thyroid hormones and autoimmunity have a direct influence. Due to the high prevalence of thyroid disease in patients with PAH, thyroid function tests should be considered in the investigation of every patient with PAH. In this review, we describe the prevalence of PAH in patients with thyroid diseases and the prevalence of thyroid disease in patients with PAH, as well as addressing the principal effects that thyroid diseases have on the respiratory system. In addition, we report the treatment effects in patients with these diseases.

Keywords: Hypertension, pulmonary; Graves disease; Hyperthyroidism; Hypothyroidism; Thyroid hormones; Echocardiography.

Objective: To evaluate the role of right heart catheterization in the diagnosis of pulmonary arterial hypertension (PAH). Methods: We evaluated clinical, functional, and hemodynamic data from all patients who underwent right heart catheterization because of diagnostic suspicion of PAH-in the absence of severe left ventricular dysfunction (LVD), significant changes in pulmonary function tests, and ventilation/perfusion lung scintigraphy findings consistent with chronic pulmonary thromboembolism-between 2008 and 2013 at our facility. Results: During the study period, 384 patients underwent diagnostic cardiac catheterization at our facility. Pulmonary hypertension (PH) was confirmed in 302 patients (78.6%). The mean age of those patients was 48.7 years. The patients without PH showed better hemodynamic profiles and lower levels of B-type natriuretic peptide. Nevertheless, 13.8% of the patients without PH were categorized as New York Heart Association functional class III or IV. Of the 218 patients who met the inclusion criteria, 40 (18.3%) and 178 (81.7%) were diagnosed with PH associated with LVD (PH-LVD) and with PAH, respectively. The patients in the HP-LVD group were significantly older than were those in the PAH group (p < 0.0001). Conclusions: The proportional difference between the PAH and PH-LVD groups was quite significant, considering the absence of echocardiographic signs suggestive of severe LVD during the pre-catheterization investigation. Our results highlight the fundamental role of cardiac catheterization in the diagnosis of PAH, especially in older patients, in whom the prevalence of LVD that has gone undiagnosed by non-invasive tests is particularly relevant.

Keywords: Hypertension, pulmonary; Cardiac catheterization, Ventricular dysfunction, left.

Objective: To develop and validate a protocol for the treadmill six-minute walk test (tread6MWT) to evaluate patients with pulmonary arterial hypertension (PAH). Methods: The study population comprised 73 patients with PAH, diagnosed by means of right heart catheterization, with or without NO inhalation. All patients performed a hallway 6MWT and three tread6MWTs based on a pre-determined incremental speed protocol and interposed by a rest period. The patients who had been submitted to hemodynamic testing using NO performed the third tread6MWT while inhaling the same dose of NO that had been used during the catheterization. Results: We found that the treadmill six-minute walk distance (tread6MWD) correlated with hemodynamic data, functional class and the hallway six-minute walk distance (6MWD). In addition, the tread6MWD correlated significantly with survival, thereby confirming the correlation with disease severity. Inhalation of NO during the tread6MWT led to variations that were consistent with the hemodynamic changes induced by the same dose of inhaled NO, suggesting that the protocol developed can reflect the effect of therapeutic interventions. Conclusions: We conclude that the tread6MWD is a useful prognostic and functional marker for the routine evaluation of PAH patients.

Keywords: Hypertension, pulmonary; Exercise test; Hemodynamics.

Idiopathic pulmonary arterial hypertension (PAH) patients with a positive response to acute vasodilator challenge and a clinical response to calcium channel blockers (CCBs) for at least one year are traditionally designated true responders. Nevertheless, little is known about a sustained response to CCBs over longer periods of time. We evaluated the loss of response to CCBs after long-term treatment in a cohort of idiopathic PAH patients previously classified as being true responders. Our data suggest that idiopathic PAH patients can lose clinical response to CCBs even after one year of clinical stability, reinforcing the need for constant multidimensional reevaluation to assess the need for targeted PAH therapies and to classify these patients correctly.

Keywords: Pulmonary hypertension; Vasodilator agents; Calcium channel blockers.