ABSTRACT
Oral treprostinil has been shown to improve exercise capacity and delay disease progression in patients with pulmonary arterial hypertension (PAH), but its effects on hemodynamics are not well-characterized. The FREEDOM-EV trial was a Phase III, international, placebo-controlled, double-blind, event-driven study in 690 participants with PAH who were taking a single oral PAH therapy. FREEDOM-EV demonstrated a significantly reduced risk for clinical worsening with oral treprostinil taken three times daily and did not uncover new safety signals in PAH patients. Sixty-one participants in the FREEDOM-EV trial volunteered for a hemodynamics sub-study. Pulmonary artery compliance (PAC), a ratio of stroke volume to pulmonary pulse pressure, significantly increased from Baseline to Week 24 in the oral treprostinil group compared with the placebo group (geometric mean 26.4% active vs. -6.0% placebo; ANCOVA p=0.007). There was a significant increase in cardiac output in the oral treprostinil group compared to the placebo group (geometric mean 11.3% active vs. -6.4% placebo; ANCOVA p=0.005) and a corresponding significant reduction in pulmonary vascular resistance (PVR) (geometric mean -21.5 active vs. -1.8% placebo; ANCOVA p=0.02) from Baseline to Week 24. These data suggest that increased compliance contributes to the physiological mechanism by which oral treprostinil improves exercise capacity and delays clinical worsening for patients with PAH.
Subject(s)
Pulmonary Arterial Hypertension , Antihypertensive Agents , Epoprostenol/analogs & derivatives , Epoprostenol/therapeutic use , Humans , Pulmonary Arterial Hypertension/drug therapy , Treatment Outcome , Vascular ResistanceABSTRACT
Pulmonary arterial hypertension is a progressive vascular disease with a high mortality rate without proper therapy. Identification of the appropriate treatment for each patient is critical in regard to adverse effects, health care costs, ease of treatment, and the potential for prognostication. Treatment strategies typically begin with acute vasoreactivity testing, which is performed during a right heart catherization. If positive, a calcium channel blocker may work; however, another pulmonary arterial hypertension-specific medication is necessary when testing is negative. Acute vasoreactivity testing is currently recommended to be performed only in certain subgroups of pulmonary arterial hypertension, but not when related to connective tissue disease. In this report, we describe a patient who had systemic sclerosis-related pulmonary arterial hypertension with a positive acute vasoreactivity test result. The patient was placed on calcium channel blocker monotherapy that has been well tolerated for 12 years, resulting in improved symptoms and exercise capacity. The long-term response to calcium channel blocker therapy in systemic sclerosis-associated pulmonary arterial hypertension has not been previously described. In addition, pulmonary artery pressures have been well controlled. The absence of genetic smooth muscle variants prevalent in vasoresponsive idiopathic pulmonary arterial hypertension is also unique.
ABSTRACT
La hipertensión pulmonar (HP) es una complicación frecuente de las enfermedades respiratorias crónicas y en particular de la enfermedad pulmonar obstructiva crónica (EPOC). En la mayoría de los casos la misma es de grado leve a moderada, de lenta progresión y se asocia a enfermedades concomitantes que deben de ser diagnosticadas y tratadas. Su aparición y progresión determina un fuerte impacto en la capacidad funcional y en la supervivencia de estos pacientes. Si bien su desarrollo está asociado con la severidad de la obstrucción al flujo aéreo,no siempre es así y se puede observar en estadios más tempranos de la misma. Una pequeña proporción de pacientes se presenta con una HP severa asociada a obstrucción bronquial leve a moderada, hipoxemia severa, hipocapnia y una capacidad de difusión pulmonar almonóxido de carbonomuy baja. Se le ha denominado HP desproporcionada, la cual presenta alta mortalidad y un rápido deterioro funcional similar a la hipertensión arterial pulmonar idiopática. El diagnóstico se confirma mediante un cateterismo cardiaco derecho, el cual se reserva para casos seleccionados. El manejo de la HP en la EPOC consiste en descartar comorbilidades, optimizar el tratamiento de la EPOC y la oxigenoterapia continua domiciliaria. No existe evidencia en la actualidad de que la HP asociada a EPOC se beneficie de algún tratamiento vasodilatador específico.
Pulmonary hypertension (PH) is a common complication of chronic respiratory diseases and, in particular, chronic obstructive pulmonary disease (COPD). In most cases it is mild, with low progression and is associated with concomitant diseases that should be diagnosed and treated. Its appearance and progression have a strong impact on the functional capacity and survival of these patients. Although it is closely related to the severity of airflow obstruction, not always is the case and it can be seen in earlier stages of the same. A small proportion of patients may develop severe PH associated with mild to moderate bronchial obstruction, severe hypoxaemia, hypocapnia and very low lung diffusion capacity. It has been called PH out of proportion and it is associated with high mortality and rapid functional worsening, similar to idiopathic pulmonary arterial hypertension. The diagnosis is confirmed by right heart catheterization which is reserved for selected cases. Management of PH in COPD relies on ruling out comorbidities, optimising therapy for COPD and long-term domiciliary oxygen therapy. At present, there is no evidence that PH in COPD would benefit from any specific vasodilator therapy.
