Registry and Survival Study in Chinese Patients With Idiopathic and Familial Pulmonary Arterial Hypertension

Survival in schistosomiasis-associated pulmonary arterial hypertension

OBJECTIVES

The objective of this study was to evaluate the natural history of untreated schistosomiasis-associated pulmonary arterial hypertension (Sch-PAH) patients as compared to idiopathic pulmonary arterial hypertension (IPAH) with respect to hemodynamics recorded at presentation and 36 months survival.

BACKGROUND

Schistosomiasis (Sch) is one of the most prevalent chronic infectious diseases in the world. Nevertheless data regarding one of its most severe clinical complications, pulmonary arterial hypertension (PAH), is scarce.

METHODS

We retrospectively analyzed case notes of all consecutive patients diagnosed of Sch-PAH and IPAH referred to the Heart Institute in São Paulo, Brazil, between 2004 and 2008. None of the Sch-PAH received PAH specific treatment whereas all IPAH patients did.

RESULTS

Sch-PH patients (n = 54) had less severe pulmonary hypertension as evidenced by lower levels of pulmonary vascular resistance (11.3 +/- 11.3 W vs. 16.7 +/- 10.6 W; p = 0.002) and mean pulmonary artery pressure (56.7 +/- 18.7 mm Hg vs. 64.6 +/- 17.4 mm Hg; p = 0.01) and higher cardiac output (4.62 +/- 1.5 l/min vs. 3.87 +/- 1.5 l/min; p = 0.009) at presentation than IPAH patients (n = 95). None of the Sch-PAH patients demonstrated a positive response to acute vasodilator testing, whereas 16.2% of IPAH patients did (p = 0.015). Survival rates at 1, 2, and 3 years were 95.1%, 95.1%, and 85.9% and 95%, 86%, and 82%, for Sch-PAH and IPAH, respectively (p = 0.49). Both groups had a higher survival rate when compared to IPAH survival as estimated by the NIH equation (71%, 61%, and 52%, respectively).

CONCLUSIONS

Sch-PAH has a more benign clinical course than IPAH despite a lack of demonstrable acute vasoreactivity at hemodynamic evaluation.

Pulmonary hypertension in China: pulmonary vascular disease: the global perspective

Significant progress has been made in understanding the pathogenesis of pulmonary hypertension (PH) and developing therapeutic approaches for PH in recent years. Most of the currently available data regarding the prevalence, diagnosis, treatment, and prognosis of PH are from American and European populations. Whether these data are also valid in the Chinese population is still controversial. China has a relatively large population of patients with PH for clinical and basic research. However, many medical centers and hospitals in China have limited experience with PH diagnosis and treatment. Given the potential higher prevalence of PH in China than in the United States and European countries, it is critical to develop suitable, effective, and novel therapeutic approaches for Chinese patients. Measures for the detection and prevention of PH need to be put in place urgently for the management of PH in China.

The estrogen paradox in pulmonary arterial hypertension

Idiopathic pulmonary arterial hypertension (PAH) is a disabling condition characterized by PA vasoconstriction and remodeling as well as in situ thrombosis and eventual right heart failure. Idiopathic PAH occurs more frequently in females than in males. The female:male ratio is 1.64 ∼ 3.88:1. Although endogenous sex hormones including estrogen have been suggested to account for the observed gender differences in PAH, a precise pathobiology for the gender differences remains uncertain. Recent studies demonstrated that estrogen exerts beneficial effects on the pulmonary vasculature. However, it seems to contradict the female predominance that is observed in idiopathic PAH. Moreover, Sweeney and Voelkel (Sweeney L and Voelkel NF. Eur J Med Res 14: 433-442, 2009) showed that early and long-term estrogen exposure might be correlated with an increased risk of the development of PAH. Here we ask the question: Is estrogen a friend or a foe? According to accumulating evidence, we postulate that the different effects of estrogens on different target cells could account for this paradox, i.e., estrogens may exert beneficial effects only on the increased muscularization of vessel walls, but not on phenotypically altered endothelial cells. The effects of estrogens on the pulmonary vasculature are potent and complex, yet not fully understood. A better mechanistic understanding may allow for future therapeutic interventions in patients with PAH.

The efficacy and safety of sildenafil in Chinese patients with pulmonary arterial hypertension

Sildenafil has been suggested to be a cost-effective treatment for pulmonary arterial hypertension (PAH). On account of the lack of data confirming its benefit in PAH patients, sildenafil has not been adopted in China for the treatment of PAH. The purpose of this study was to evaluate the efficacy, safety and 1-year survival of Chinese patients with PAH treated with sildenafil. Sixty Chinese patients with PAH were enrolled in this preliminary study. Their 6-min walk distance, WHO functional class and hemodynamic parameters (such as right atrial pressure, pulmonary arterial pressure, cardiac index and pulmonary vascular resistance) at both baseline and 16 weeks after initiation of sildenafil treatment were recorded. In addition, 1-year overall survival was assessed in this cohort. The 6-min walk distance improved from 392.13+/-91.35 to 467.22+/-80.38 m during the course of treatment (P<0.001). There was a significant decrease in the mean pulmonary vascular resistance (15.28+/-8.12-14.99+/-7.88 Woods units; P=0.02) and a significant increase in the mean cardiac index (2.39+/-0.90-2.75+/-0.92 l/min/m(2), P=0.006) of the included patients at 16 weeks. The mean systemic oxygen saturation improved significantly at 16 weeks (91.44+/-7.54%-94.11+/-4.28%; P=0.002). No serious adverse reactions were reported. The Kaplan-Meier analysis showed that the 1-year survival rate improved significantly in the sildenafil-treated cohort compared with predicted survival (94.7% compared with 63.3%, P=0.03). In conclusion, sildenafil may be a safe and effective treatment for Chinese PAH patients. Sildenafil, when added to conventional therapy, was associated with improvements in exercise capacity, hemodynamic parameters and overall survival in a cohort of Chinese patients with PAH.

Pulmonary hypertension caused by sarcoidosis

Pulmonary hypertension is an uncommon complication of sarcoidosis, but in severe pulmonary disease it occurs frequently. It is an important cause of cryptogenic dyspnea in sarcoidosis patients and can occur despite the absence of pulmonary fibrosis. The true prevalence is unknown. With the advent of specific therapies for pulmonary hypertension, there has been a resurgence of interest in the pathophysiology, diagnosis, and treatment of sarcoidosis-associated pulmonary hypertension. This article reviews the status of the current epidemiologic, pathophysiologic, and therapeutic knowledge regarding this entity.

Design of the REVEAL registry for US patients with pulmonary arterial hypertension

The Registry to Evaluate Early and Long-term PAH Disease Management (REVEAL) has been designed to meet the need for current information about patients with pulmonary arterial hypertension (PAH). The main objectives of REVEAL are to better define and understand PAH and to assess the consequences of treatment strategies. REVEAL is collecting clinically relevant data from 3500 consecutively enrolled patients with confirmed PAH diagnoses. Outcomes will be evaluated longitudinally and compared according to the baseline classification of PAH. The primary outcome for group comparisons will be survival. Collected data include World Health Organization functional class, 6-minute walk distance, cardiopulmonary exercise testing, pulmonary function test results, hemodynamic measurements, functional status, hospitalizations, and death. REVEAL will be the richest source of data on patients with World Health Organization group I PAH.