Faculty Bibliography

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.

A retrospective analysis of 23 patients was undertaken to evaluate the outcome of pulmonary rehabilitation (PR) in patients with pulmonary hypertension (PH) over a preceding 6-year time frame. Chart review and data analyses were undertaken evaluating pulmonary arterial hypertension pharmacotherapy versus the same therapy with the addition of PR. Analysis included 23 patients who had a mean pulmonary artery pressure of 36.6 while on therapy and who had initial six-minute walk tests (6MWTs) ranging between 54 and 396 meters. Outcomes included 6MWTs and Saint George's Respiratory Questionnaire. There was no improvement in 6MWT postpharmacotherapy. Patients with low 6MWT <250 meters had substantial gains in 6MWT postrehabilitation (average of 86 meters). As well, those with initial 6MWT >250 meters had a significant improvement of 52.55 meters, documenting the utility of PR in patients with PH. PH patients are increasingly seen in PR clinics as they share many characteristics present in chronic respiratory disease states. There is increasing literature supporting the utility of PR in this population. We have found that patients with 6MWTs as low as <250 meters are also candidates for PR and can demonstrate substantial benefits as measured using the 6MWTs.

Calcific uremic arteriolopathy (CUA) is a rare and potentially fatal disorder of calcification involving subcutaneous small vessels and fat in patients with renal insufficiency. We describe the successful use of intravenous sodium thiosulfate (STS) for the treatment of CUA in two patients. The first case was complicated by the development of a severe anion gap metabolic acidosis, which was accompanied by a seizure. Both patients had complete wound healing within five months. Although STS should be considered in the treatment of CUA, little is known about pharmacokinetics and additional studies are required to determine dosing strategies to minimize severe potential side effects.

Pulmonary arterial hypertension (PAH) is characterized by progressive increases in pulmonary vascular resistance, leading to right heart failure and death. Guidelines recommend customization of treatment, necessitating the development of effective strategies for transitioning patients among treatments. In this study, we characterized our experience with patient transitions from parenteral prostacyclin to inhaled iloprost. We retrospectively assessed records from 11 centers of 37 consecutive patients with PAH aged >/= 18 years who were treated with intravenous (IV) or subcutaneous (SC) prostacyclin analogues and transitioned to inhaled iloprost. The transition period began on the first day of inhaled iloprost with the intent of discontinuing parenteral prostacyclin and ended on the first day on inhaled iloprost free of parenteral prostacyclin. Persistence was defined as the absence of (1) parenteral prostacyclin while remaining on inhaled iloprost during post-transition Days 1-90 and (2) no reinitiation of parenteral prostacyclin during post-transition Days 90-365. All patients were clinically stable before transitioning to inhaled iloprost. The mean age was 46.5 years, 70.3% were female, 51.4% had idiopathic PAH, and 43.0% were in New York Heart Association Functional Class III. Among patients with an overlapping transition, the mean transition period was 10.5 days. A transition dosing algorithm was used in 10 patients (27.0%). At one year, 78.4% of the patients remained persistent on inhaled iloprost and 81.1% were free of clinical worsening. In selected patients on background oral PAH therapy, transitioning from parenteral prostacyclin to inhaled iloprost appears safe and feasible and is associated with long-term success. Further study is needed to define the optimal patient selection criteria and transition algorithm.