Frantz, Robert P.

Introduction: Creation of an atrial septal defect via atrial septostomy (AS) is a therapeutic option traditionally utilized for PAH in settings where medical therapy was unavailable. Its utility in the context of progressive disease despite medical therapy remains incompletely understood. Hypothesis: AS may be a useful option in patients with symptomatic PAH despite medical therapy and may improve functional class. Methods: Single center retrospective study of all adult PAH patients receiving AS at a tertiary PAH referral center. Results: Eleven atrial septostomy procedures were performed in 8 patients who were refractory to maximal medical management. All patients were WHO functional class III or IV and average patient age was 40 ± 13 years with a female predominance (89%). Mean RA pressure was 18 ± 4 mm Hg with cardiac index of 2.28 ± 0.82 L/min/m 2 prior to AS. Mean pulmonary artery pressure was 63 mm Hg with a pulmonary artery saturation of 48% and average systolic blood pressure of 97 mm Hg. Baseline NT-proBNP was 5573 ± 4589 pg/ml with a mean 6 minute walk distance (6MWD) of 311 ± 131 meters. Five of the 11 procedures resulted in functional class improvement. Functional class change did not relate to change in 6MWD or NT-pro BNP level. Three patients had repeat AS due to spontaneous narrowing of the original septostomy, with a mean duration of 220 ± 135 days between procedures. One patient died within 30 days of the procedure and another at day 88 while one patient received a heart/lung transplant at day 42 post AS. Mean follow up was 243 ± 183 days. The REVEAL risk scores ranged from 10 to 15, with predicted 1 year survival from pre-septostomy clinical data ranging from 22% to 80% (mean predicted survival of 57%). Actual transplant free survival at 1 year was 63%. Conclusions: Selected patients at high risk for 1 year mortality may receive symptomatic benefit from atrial septostomy. One year mortality remains high, and not significantly different from that predicted by the REVEAL score. Atrial septostomy may be a palliative treatment option for patients who are refractory to maximal medical therapy but further long term investigation is necessary.

BACKGROUND: The immunologic risk associated with preformed donor-specific allo-antibodies (DSA) against human leukocyte antigens (HLA) in heart transplant (HTX) recipients is unclear. The goal of this study was to evaluate potential role of DSA on the progression of cardiac allograft vasculopathy (CAV) in HTX recipients. METHODS: The presence of DSA against HLA was evaluated using solid phase Single Antigen Bead assay (One Lambda, Inc., Canoga Park, CA; Luminex platform) before transplant in 35 HTX recipients. Using alloantibody specification analysis, 11% (4/35) and 20% (7/35) had DSA against donor Class I and II HLA respectively including the one patient who had both (DSA I & II+) . 71% (25/35) of patients had no demonstrable DSA (DSA-). All patients had negative cytotoxicity cross match. Baseline three-dimensional intravascular ultrasound studies (3D IVUS) were performed at 1.0 [0.18, 1.4] year after transplant. Follow up 3D IVUS exams were performed 0.92 [0.85, 1.04] years after the baseline exam. RESULTS: The increase in mean plaque (media and intima) volume (PV) was accelerated in the DSA II+ group as compared to the DSA- group (0.87±1.9 mm (3)/mm vs. 0.16±1.8 mm (3)/mm) but the vessel volume index (follow up vessel volume/ baseline vessel volume) was similar between groups (1.08±0.5 vs. 1.09± 0.4; p=0.9). Plaque index (PI) (PV/vessel volume x 100 [%]) increased significantly in the DSA II+ group (17.9±6.3%) but not in the DSA- group (-13.6±13.2%, P=0.02). None of these values were significant in the DSA I+ only group. Treatment with Sirolimus did not affect PI progression between the DSA II+ and DSA- groups (PI progression: 15.9±8.7% vs. -11.7±7.1%, P=0.03). Age, gender, lipid and uric acid levels, prevalence of diabetes, ischemic time, time between IVUS examinations, the use of steroids, mycophenolate vs. azathioprine or calcineurin inhibitors vs. sirolimus were not different between the groups (P>0.4 for all). CONCLUSIONS: Heart transplant recipients with clearly defined anti-Class II DSA are at risk for accelerated cardiac allograft vasculopathy. Whether interventions to minimize the risk of DSA such as virtual crossmatch, desensitization and complement inhibition will retard CAV remains to be proven.