Uncertainties in the Diagnosis and Treatment of Pulmonary Arterial Hypertension

Abstract

Abstract-The availability of new treatments for patients with pulmonary arterial hypertension has increased awareness and interest in the medical community for pulmonary vascular diseases in general. Many uncertainties exist, however, regarding the diagnosis and treatment of patients with pulmonary arterial hypertension that are particularly pertinent for the management of patients with idiopathic pulmonary arterial hypertension and pulmonary hypertension associated with underlying diseases. This review highlights controversial issues around the definition and diagnosis of pulmonary hypertension, the interpretation of hemodynamic variables, and the interpretation of clinical responsiveness to chronic therapies. In addition, we propose guidelines applicable to the conduct of new therapeutic trials in pulmonary arterial hypertension, which aim to provide greater confidence in the efficacy and safety of new treatments currently under development. Key Words: catheterization Ⅲ hypertension, pulmonary Ⅲ hypoxia Ⅲ trials Ⅲ vasoconstriction P ulmonary hypertension from any cause is more prevalent than previously believed. As reported in a Centers for Disease Control study of the prevalence of pulmonary hypertension in the United States, more than 260 000 people were discharged from the hospital with a diagnosis of pulmonary hypertension in 2002. 1 It is likely that the increasing attention being paid to making a diagnosis of pulmonary hypertension is related to the fact that there are now therapies available that were not available a decade ago to treat these patients. 2 Furthermore, the broad availability of Doppler echocardiography has helped with (earlier) detection of pulmonary hypertension.A new classification of clinical pulmonary hypertension, which was revised recently, 3 designated 5 categories that are distinctive because they differ in their clinical presentation, diagnostic findings, and response to treatment (Table 1). 4 As we now know, a treatment that is effective for one cause of pulmonary hypertension can worsen the prognosis for pulmonary hypertension due to a different cause. 5 Equally important is the fact that some treatments for pulmonary hypertension can be lifesaving, and the failure to make a correct diagnosis in a patient who is potentially curable could be catastrophic. 6 It is also important to emphasize that the approved treatments for pulmonary arterial hypertension (PAH; category 1, the only category of pulmonary hypertension for which treatments are approved) have serious side effects, are exceedingly expensive, and have not been shown to be effective in patients with other forms of pulmonary hypertension. When one takes into account the mortality associated with pulmonary hypertension, as well as the risks and benefits of the different treatments, it becomes apparent that an accurate diagnosis of the cause of pulmonary hypertension is as essential as the correct diagnosis of the type of tumor in a patient with cancer. Uncertainties With the Definition of PAHThere appear to be discrepanci...

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