Faculty Bibliography

Pulmonary hypertension (PH) is an end result of a diverse array of complex clinical conditions that invoke hemodynamic and pathophysiological changes in the pulmonary vasculature. Many patients' symptoms begin with dyspnea on exertion for which screening tests such as chest roentgenograms and more definitive noninvasive tests such as CT scans are ordered initially. It is imperative that clinicians are cognizant of subtle clues on these imaging modalities that alert them to the possibility of PH. These clues may serve as a stepping stone towards more advanced noninvasive (echocardiogram) and invasive (right heart catheterization) testing. On the CT scan, the signs are classified into mediastinal and lung parenchymal abnormalities. In addition to suspecting the diagnosis of PH, this paper provides a pictorial essay to guide health care professionals in identifying the etiology of PH. This paper also provides concrete definitions, wherever possible, of what constitutes abnormalities in PH, such as dilated pulmonary arteries, pruning of vessels, and increased thickness of free wall of the right ventricle. The sensitivities and specificities of each sign are enumerated. The common radiographic and clinical features of many different etiologies of PH are tabulated for the convenience of the readers. Some newer imaging modalities such as dual-energy CT of the chest that hold promise for the future are also described.

OBJECTIVES: The aim of this study was to determine the prevalence of exercise-induced pulmonary hypertension (EIPH) in consecutive subjects referred for stress echocardiography for chest pain or shortness of breath and correlate echocardiographic diagnosis of EIPH with hemodynamics at right heart catheterization (RHC). BACKGROUND: Elevated pulmonary pressure can lead to significant morbidity and mortality. EIPH by ehocardiography has been described in patients with connective tissue disease. It's prevalence in the setting of routine clinically indicated stress echocardiography unknown. METHODS: In a retrospective analysis of 4068 consecutive stress subjects undergoing stress echocardiography, 479 subjects with EIPH were identified. All 479 subjects with EIPH were compared to 479 age and sex matched subjects with normal pulmonary artery pressures post exercise. EIPH was defined as PASP>50mmHg or peak tricuspid regurgitation velocity>3.2m/s. Of 100 patients with EIPH who underwent RHC we identified variables which predicted abnormal hemodynamic findings on RHC. RESULTS: The prevalence of EIPH in subjects referred for stress echocardiography was 11.7%. A greater proportion of subjects with EIPH were obese or had lung disease or connective tissue disease. Of 100 subjects who underwent RHC, 65 had abnormal results. Age>55years (OR 5.1, p<0.01]) or dilated left atrium (OR 4.4, p=0.02]) were independently associated with abnormal right heart hemodynamics. CONCLUSIONS: The results demonstrate that 11.7% of patients undergoing clinically indicated stress echocardiography have EIPH. Of those who underwent RHC abnormal hemodynamics were significantly associated with a dilated left atrium or age older than 55years.

Pulmonary hypertension (PH) due to chronic respiratory disease and/or hypoxia is classified as World Health Organization (WHO) Group III pulmonary hypertension. The patients most commonly encountered in clinical practice with group III PH include those with chronic obstructive lung disease (COPD), diffuse parenchymal lung disease, and sleep-disordered breathing. The purpose of this review is to outline the variable clinical significance of pulmonary hypertension in the most common pulmonary disease states and how a clinician may approach the management of these patients.

INTRODUCTION: Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are rare, life-threatening diseases in which chronically elevated pressure in the pulmonary arteries results in vascular remodeling and right heart failure. Treatment goals are to improve patient functioning, exercise capacity, and symptoms; delay disease progression; normalize the right ventricular function; and, ultimately, improve survival. Therapeutic management centers on the affected physiologic pathways and includes endothelin receptor antagonists, phosphodiesterase-5 inhibitors, and prostacyclins. Recently, riociguat, a novel therapeutic agent that stimulates soluble guanylate cyclase via the nitric oxide pathway, was approved for the treatment of both PAH and CTEPH. Clinical trial data show that riociguat significantly improves exercise capacity as well as hemodynamic parameters in PAH/CTEPH. METHODS: We report on the early use of riociguat at our center-a large, metropolitan pulmonary hypertension treatment facility that cares for >250 patients with PAH/CTEPH. Through our initial clinical experience, we offer evidence on the benefits of riociguat in three patients with PAH associated with different etiologies, symptoms, and treatment goals. RESULTS: Overall, patients at our center who have received riociguat have experienced clinical benefits, including improvement in symptomatic and hemodynamic parameters, increase in 6-min walk distance, and improvement or stabilization of World Health Organization functional class. In several cases, initial response to riociguat has been encouraging and has helped patients reach their treatment goals. Riociguat appears to be well tolerated, with only one patient experiencing mild, self-limiting side effects. CONCLUSION: Novel agents are continuously being introduced into the PAH/CTEPH armamentarium, and clinicians must decide how best to integrate them into their existing treatment algorithms. This case series offers initial evidence from our practice on the benefits of riociguat in optimizing hemodynamic and functional parameters. These benefits have been observed in PAH associated with different etiologies and functional status, and in both first-line and combination use. FUNDING: Bayer HealthCare Pharmaceuticals.