Characteristics and Outcomes of Patients in the Emergency Department with Left Ventricular Assist Devices.

Introduction: Left ventricular assist devices (LVAD) are increasingly common among patients with heart failure. The unique physiologic characteristics of patients with LVADs present a challenge to emergency clinicians making treatment and disposition decisions. Despite the increasing prevalence of LVADs, literature describing emergency department (ED) visits among this population is sparse. We aimed to describe clinical characteristics and outcomes among patients with LVADs seen in two quaternary-care EDs in a five-year period. Secondarily, we sought to evaluate mortality rates and ED return rates for bridge to transplant (BTT) and destination therapy (DT) patients. Methods: We conducted a retrospective cohort study of adult patients known to have an LVAD who were evaluated in two quaternary-care EDs from 2013-2017. Data were collected from the electronic health record and summarized with descriptive statistics. We assessed patient outcomes with mixed-effects logistic regression models including a random intercept to account for patients with multiple ED visits. Results: During the five-year study period, 290 ED visits among 107 patients met inclusion criteria. The median patient age was 61 years. The reason for LVAD implantation was BTT in 150 encounters (51.7%) and DT in 140 (48.3%). The most common presenting concerns were dyspnea (21.7%), bleeding (18.6%), and chest pain (11.4%). Visits directly related to the LVAD were infrequent (7.9%). Implantable cardioverter-defibrillator discharge was reported in 3.4% of visits. A majority of patients were dismissed home from the ED (53.8%), and 4.5% required intensive care unit admission. Among all patients, 37.9% returned to the ED within 30 days, with similar rates between DT and BTT patients (32.1 vs 43.3%; P = 0.055). The LVAD was replaced in three cases (1.0%) during hospitalization. No deaths occurred in the ED, and the mortality rate within 30 days was 2.1% among all patients. Conclusion: In this multicenter cohort study of ED visits among patients with an LVAD, dyspnea, bleeding, and chest pain were the most common presenting concerns. Visits directly related to the LVAD were uncommon. Approximately half of patients were dismissed home, although return ED visits were common.

Intraoperative and In Vitro Classification of Subacromial Bursal Tissue.

PURPOSE: To classify subacromial bursal tissue using intraoperative and in vitro characteristics from specimens harvested during arthroscopic shoulder surgery. METHODS: Subacromial bursa was harvested over the rotator cuff from 48 patients (57 ± 10 years) undergoing arthroscopic shoulder surgery. Specimens were characterized intraoperatively by location (over rotator cuff tendon or muscle), tissue quality (percent of either fatty or fibrous infiltration), and vascularity before complete debridement. Nucleated cell counts were determined after 3 weeks incubation and histological sections were reviewed for degree of fatty infiltration and vascularity. Mesenchymal stem cell surface markers were counted via flow cytometry (n = 3) and cellular migration was observed using a fluoroscopic assay (n = 3). RESULTS: Intraoperatively, muscle bursa was found most often to have >50% fatty infiltration (n = 39), whereas tendon bursa showed majority fibrous tissue (n = 32). Cellular proliferation did not significantly differ according to intraoperative tissue quality. Intraoperative vascularity was associated with greater proliferation for highly vascular samples (P = 0.023). Tendon bursa demonstrated significantly greater proliferation potential than muscle bursa (P = 0.00015). Histologic assessment of fatty infiltration was moderately correlated with gross tissue fattiness (ρ = -0.626, P = 7.14 × 10-11). Flow cytometry showed that 90% to 100% of bursal cells were positive for MSC surface markers. Peak cellular migration rates occurred between 18 and 30 hours' incubation. CONCLUSIONS: Intraoperative and in vitro subacromial bursa characteristics were not found to reliably correlate with the degree of cellular proliferation. However, the anatomic location of subacromial bursa was consistently predictive of increased proliferation potential. Bursa-derived nucleated cells were confirmed to include mesenchymal stem cells with migratory potential. CLINICAL RELEVANCE: The anatomic distinction between muscle and tendon bursa provides a simple classification for predicting cellular activity.