De Novo Pulmonary Arterial Hypertension After Heart Transplantation

Abstract

Background Orthotopic heart transplantation (OHT) recipients undergo scheduled right heart catheterizations (RHC) and biopsies. Some of these patients who have mixed connective tissue disease (MCTD) are at increased risk of developing pulmonary artery hypertension (PAH). The natural history and impact of immunosuppression on new-onset PAH is unknown. Case A 43 year old male required OHT after the development of lupus cardiomyopathy. Post-transplant he was treated with tacrolimus and mycophenolate. Three years later, he developed significant dyspnea on exertion. His serology was anti-nuclear antibody positive (1:2560, speckled). Over eight months, RHCs performed in the setting of endomyocardial biopsies for surveillance of rejection showed a dramatic change, from normal shortly after transplantation, to a markedly elevated PA pressure of 81/34 (mean 52) mmHg, pulmonary capillary wedge pressure of 7 mmHg, transpulmonary gradient of 45 mmHg, and pulmonary vascular resistance of 9.36 Wood units (Figure 1). The patient's constellation of symptoms and RHC findings supported a diagnosis of MCTD - PAH, despite ongoing immunotherapy. Severe PAH occurred incidentally while being monitored with RHC for another indication. He was treated with tadalafil, ambrisentan, and amlodipine with an improvement in functional class. Conclusions This case describes de novo development of PAH after OHT in a patient with MCTD, despite anti-rejection immunotherapy. This suggests a lack of efficacy of immunosuppression in preventing scleroderma-PAH and highlights the rapidity of onset of this disease. Figure 1. Results of serial right heart catheterizations