Add-on sildenafil therapy for chronic thromboembolic pulmonary hypertension

The pulmonary hypertension that develops in chronic pulmonary thromboembolic diseases is caused by both mechanical obstruction of the vascular lumen and vascular remodeling, with pathological features similar to those of idiopathic pulmonary arterial hypertension (IPAH). The therapeutic efficacy of pulmonary thromboendarterectomy (PTE) in surgical candidates with chronic thromboembolic pulmonary hypertension (CTEPH) is well-established [Doyle RL, McCrory D, Channick RN, Simonneau G, Conte J. Surgical treatments/interventions for pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines. Chest 2004;126:63S–71S]. For CTEPH patients who are ineligible for PTE, therapeutic effects of various vasodilators in treatment of IPAH have been demonstrated. Although sildenafil, a phosphodiesterase type-5 inhibitor, has been reported to have short- and long-term benefits in terms of hemodynamics and functional status for inoperable CTEPH patients [Ghofrani HA, Schermuly RT, Rose F, Wiedemann R, Kohstall MG, et al. Sildenafil for long-term treatment of nonoperable chronic thromboembolic pulmonary hypertension. Am J Respir Crit Care Med 2003;167:1139–41; Sheth A, Park JE, Ong YE, Ho TB, Madden BP. Early haemodynamic benefit of sildenafil in patients with coexisting chronic thromboembolic pulmonary hypertension and left ventricular dysfunction. Vascul Pharmacol 2005;42:41–5], its role in CTEPH treatment for PTE candidates unwilling to undergo operation has not been explored specifically. We present the case of a 50-year-old female CTEPH patient who was a traditional candidate for PTE with poor clinical response to 3 months of anticoagulant therapy, where dramatic improvements were achieved after adding on 4 months of sildanefil treatment. Her treatment course is detailed, and we discuss the potential therapeutic effects of sildenafil for CTEPH.