PVOD is Highly Prevalent in Scleroderma Patients Undergoing Lung Transplant

SESSION TITLE: Hot Topics in PAH SESSION TYPE: Original Investigation Slide PRESENTED ON: Wednesday, October 28, 2015 at 04:30 PM - 05:30 PM PURPOSE: Pulmonary hypertension (PH) is the leading cause of morbidity and mortality in scleroderma (SSC), presenting as pulmonary arterial hypertension (SSC-PAH) or associated with interstitial lung disease (SSC-PH-ILD). Although SSC-PH-ILD patients have a 5-fold increased mortality compared to SSC-PAH, both groups have worse prognosis and poor response to vasodilator therapies compared to idiopathic PAH (IPAH). Pulmonary veno-occlusive disease (PVOD) has been reported in those with SSC-PAH, however, the prevalence of PVOD in patients with SSC-PH-ILD remains unknown. METHODS: A retrospective study of SSC patients with a diagnosis of PH was performed on sequential patients transplanted between 01/01/2007 and 10/01/2013. Patients were excluded if there were no pathology slides available for review. Control samples were obtained from transplanted patients without SSC who had IPAH (n = 3) or PVOD (n=3). PVOD pattern was classified as absent (0), mild (1+) or moderate-severe (2+) based on histological examination of the explanted lung. Comprehensive vessel morphometry was also performed. The continuous variables were analyzed with Kwallis and categorical variables with fisher's exact test. RESULTS: All 18 patients included had SSC-PH-ILD. 9 had 1+ PVOD and 6 had 2+ PVOD, while PVOD was absent in the remaining 3. Patients with PVOD had lower pulmonary artery pressures compared to those with no PVOD. There were no plexiform lesions in all SSC patients. The pulmonary vein smooth muscle % was lower in 2+ PVOD (p = 0.09). The odds of having one higher category of PVOD increased 10-fold in those with limited versus diffuse SSC (CI 0.77-133.4, p=0.07). CONCLUSIONS: There is an unexpectedly high incidence of PVOD in patients with SSC-PH-ILD, and the prevalence is higher in those with limited versus diffuse SSC. Presence of PVOD may be an unrecognized contributor to the dismal prognosis of these patients. CLINICAL IMPLICATIONS: SSC-PH-ILD has significantly worse survival compared to SSC-PAH, despite the availability of PAH therapies. This has been attributed to worsening ventilation-perfusion mismatch. Our results suggest that a higher prevalence of PVOD may also play a role in this disease. Early transplant referral should be considered for those with SSC-PH-ILD. DISCLOSURE: The following authors have nothing to disclose: Shikha Gupta, Aman Gupta, Iclal Ocak, Robin Domsic, Frank Schneider, Patricia George No Product/Research Disclosure Information