Abstract Background Hemocompatibility‐related adverse events (HRAE) negatively influence survival. However, no study has examined the impact of these events on health‐related quality of life (HRQOL) and functional outcomes following continuous‐flow left ventricular assist device implantation (CF‐LVAD). We assessed the impact of HRAE events on HRQOL and hypothesized that HRAE's adversely impact HRQOL and functional outcomes. Methods INTERMACS database identified patients undergoing primary CF‐LVAD implantation from 2008 to 2017. HRAEs included stroke, non‐surgical bleeding, hemolysis, and pump thrombosis and were identified as defined in the literature. HRAEs were further stratified as Tier 1–2 and disabling stroke events. Time‐series analysis was executed for HRAE patients with values pre‐HRAE, post‐HRAE, and closest to 12 months follow up. Local polynomial regression curves modeling individual patients were superimposed into “spaghetti” plots. Results All HRQOL and functional metrics improved in patients over time, despite HRAE complications. However, these patient metrics were significantly reduced compared to the non‐HRAE cohort. Advanced data visualization techniques noted a decline after experiencing an HRAE with a subsequent recovery to baseline levels or higher. Six‐minute walk test (6MWT) was noted to be most affected in the post‐HRAE period but recovered similar to other metrics. Conclusions The burden of HRAE following CF‐LVAD implantation did not negatively impact the quality of life. However, the 6MWT did not increase in the post‐HRAE period in all HRAE patients. Improvement of heart failure symptoms after CF‐LVAD coupled with optimal management following the HRAE act to preserve the enhanced quality of life.
Reply to: Burosumab for Tumor-Induced Osteomalacia: not Enough of a Good Thing
Abstract Prothrombin complex concentrate (PCC) administration has increased among cardiac surgery patients in recent years; however, use in LVAD implantation/exchange is not widespread due to the fear of thrombotic complications. The purpose of this study was to compare the clinical outcomes of patients undergoing LVAD implantation/exchange with intraoperative PCC administration versus traditional transfusion practices alone. Adult LVAD implants/exchanges at our institution between 2015 and 2018 were included. Patients were categorized as receiving intraoperative PCC or no‐PCC (traditional). The primary outcome was the need for allogenic transfusion and transfusion volume at 48 hours after initial intensive care unit (ICU) admission. Secondary outcomes included metrics of morbidity and mortality. A total of 160 patients (39 PCC, 121 traditional) were analyzed. In unadjusted analysis, patients in the PCC group received lower intraoperative transfusion volumes compared to the traditional group although not statistically significant (1464 mL [IQR 796, 4876] vs. 2568 mL [IQR 1292, 3606]; P value .37). In the fully adjusted analysis, patients in the PCC group had increased odds of transfusion within 48 hours of ICU admission (OR 4.06, 95% CI: 1.35‐12.20; P < .01); however, there was no significant difference in transfusion volumes ( P = .09). Patients receiving PCCs had higher incidence of deep vein thrombosis (10.3% vs. 0%; P < .01) and 30‐day mortality (17.9% vs. 4.1%; P < .01). LVAD pump thrombosis occurred in 2.6% versus 0.8% in the PCC and traditional groups, respectively; P = .98. Patients undergoing LVAD implantation and exchange represent a complex surgical cohort. The results of this study suggest that the intraoperative PCC use during LVAD implant/exchange was associated with reduced intraoperative transfusions. Intraoperative PCC use was, however, associated with higher odds of postoperative transfusion, although transfusion volumes were not significantly different. While the deep vein thrombosis and 30‐day mortality rates were higher in the PCC group, these results are likely related to the degree of surgical and patient complexity rather than PCC use itself. Further studies are needed to assess PCC use in this surgical cohort.
Burosumab for the Treatment of Tumor-Induced Osteomalacia
Abstract Tumor-induced Osteomalacia (TIO) is a rare condition in which excess FGF23 produced by a tumor leads to renal phosphate wasting, impaired 1,25(OH)2D synthesis, osteomalacia, fractures, weakness, fatigue, and decreased mobility. In an ongoing open-label Phase 2 study (NCT02304367), 17 adults with TIO or cutaneous skeletal hypophosphatemia syndrome (CSHS) were enrolled and received burosumab, a fully human monoclonal antibody against FGF23. Key endpoints were changes in serum phosphorus and osteomalacia as assessed from trans-iliac crest bone biopsies. This report excludes 3/17 subjects who did not have TIO: 2 subjects diagnosed with X-linked hypophosphatemia post-enrollment and 1 subject with CSHS. Serum phosphorus increased from baseline (BL; 1.60 mg/dL) and was maintained after titration, from Week (W) 22 (2.85 mg/dL, dosing cycle midpoint) to W144 (2.56 mg/dL, dosing cycle endpoint, p<0.0001). Serum TmP/GFR and 1,25(OH)2D also increased with burosumab. Eleven subjects underwent paired bone biopsies at BL and W48. Osteoid volume/bone volume decreased from a mean ± SE of 17.6% ± 5.9% at BL to 12.1% ± 4.7% at W48 (p=0.086). Mean ± SE osteoid thickness decreased from 16.5 ± 3.6 µm to 11.3 ± 2.8 µm (p<0.05). Using imputation (Dempster et al. 2012), mineralization lag time decreased from a mean ± SE of 1598 ± 420 days to 1032 ± 712 days (p=0.41). Osteoid surface/bone surface showed no change from BL (mean ± SE BL: 57% ± 9%, W48: 57% ± 7%). Of 249 areas identified with increased uptake on bone scan at BL, 68 (27%) and 81 (33%) were fully healed at W96 and W144, respectively; 56 (23%) and 32 (13%) were partially healed at W96 and W144, respectively. Mean (SD) Global Fatigue Score decreased from 5.6 (2.5) at BL to 3.5 (3.0) at W48, and to 3.8 (2.2) at W144 (both p<0.01). All 3 domains of the Brief Pain Inventory decreased with burosumab (W144 Pain Severity and Pain Interference p<0.05), indicating reduced pain. The SF-36 mean (SD) physical component summary score increased from 33 (10) at BL to 39 (10) at W48 (p<0.05) and to 41 (12) at W144 (p<0.01), indicating improved physical functioning. The mean (SD) number of sit-to-stand repetitions, an assessment of proximal muscle function, increased from 6.7 (4.2) at BL to 8.5 (4.2) at W48 (n=10; p<0.01). All subjects had ≥1 adverse event (AE). Two subjects discontinued: 1 to undergo chemotherapy to treat an AE of neoplasm progression and 1 failed to meet serum phosphorus dosing criteria and therefore received minimal burosumab dosing. There were 16 serious AEs in 7 subjects, all unrelated to drug. Of the 6 subjects with a serious AE of tumor progression/compression, 5 had a history of tumor progression prior to enrollment. There was 1 death, considered unrelated to treatment. In adults with TIO Syndrome, burosumab was associated with improvements in phosphate metabolism, osteomalacia, skeletal metabolism/fracture healing, physical functioning, fatigue, pain, and quality of life.
OR13-1 Burosumab Improves the Biochemical, Skeletal, and Clinical Symptoms of Tumor-Induced Osteomalacia Syndrome