Abstract 1122‐000022: Delays in Care for Patients with Acute Stroke During Hospitalization for Other Reasons

Introduction : In‐hospital stroke (IHS) is defined as stroke that occurs during hospitalization for non‐stroke conditions. We aimed to understand the timing of symptom recognition for patients who experienced IHS and its impact on the care they receive. Methods : A prospective, single center registry of adult patients (9/20/19‐2/28/21) was queried for acute anterior circulation IHS. Indications for hospitalization, delays from last known well (LKW) to symptom recognition, imaging, and treatment were explored. Results : Of 928 consecutively evaluated adults with acute stroke, 85 (9%) developed an anterior circulation IHS, 39 (46%) of whom were female, with a median age of 67 years (IQR 60–76) and median NIHSS of 15 (IQR 4–22). Sixty‐eight (80%) had a >1 hour delay from last known well to symptom recognition. Two patients (2%) received IV thrombolysis, although another 38 (45%) would have been eligible if not for a delay in symptom recognition. An ICA, M1, or M2 occlusion was observed in 18 patients (21%), 7 of whom were treated at a median of 174 minutes after LKW (IQR 65–219). Compared to the 11 patients who did not undergo thrombectomy with large vessel occlusion, those who underwent thrombectomy had non‐significantly shorter delays from LKW until neuroimaging (median 85 [IQR 65‐162] vs. 216 [IQR 133‐507], p = 0.12). Conclusions : While uncommon, patients with IHS experience delays in symptom recognition and treatment, which lead to exclusion from acute care treatment such as thrombolysis and thrombectomy. Earlier detection with more frequent nursing assessments or advanced neuromonitoring devices in at‐risk patients may reduce delays in care.

Imaging of the right heart

The right ventricle has lost its designation as the ‘forgotten ventricle’ over the past decade. Clinicians recognize its prognostic significance in a wide array of disease processes and imagers are now providing an assessment of right ventricular size and function in most studies. Despite this recognition, imaging the right heart presents numerous challenges to the imager. The shape of the chamber, the unique structure, and its coupling to the pulmonary circulation mandate a different approach to its evaluation as compared to the left ventricle. Imaging may be done by several modalities, each with their own strengths and limitations. Even more so than with the left ventricle, the findings must be interpreted in the context of loading conditions and clinical setting. This chapter will focus on the two main right heart imaging modalities—echocardiography and cardiac MRI.

Abstract P152: Missed Treatment Opportunities and Earlier Stroke Detection Among Hospitalized Patients With Acute Cerebral Infarction

Background: In preparation for a quality improvement study, we queried our prospective stroke registry for patients who might benefit from prophylactic monitoring in order to estimate the time advantage to monitoring. Methods: A prospective, single center registry of adult patients (9/20/19-6/30/20) was queried for in-hospital acute anterior circulation strokes. Indications for hospitalization as well as delays from last known well (LKW) to symptom recognition, imaging, and treatment were explored. Results: Of 540 consecutively evaluated adults with acute stroke, 68 (12.6%) developed an anterior circulation infarction while hospitalized, 32 (47.1%) of whom were female with a median age of 66 years (IQR 60-77) and median NIHSS of 14 (IQR 4-22). Four patients (5.9%) received intravenous thrombolysis although another 20 (29.4%) would have been eligible for thrombolysis if not for a delay in symptom recognition. An internal carotid, M1, or M2 occlusion was observed in 13 patients (19.1%), 8 of whom were treated at a median of 198 minutes after LKW (IQR 102-670; Figure). In patients treated endovascularly or with thrombolytics, the delay from LKW to symptom recognition accounted for 55.5% of the delay in care. Conclusions: One-third of patients in this single-center cohort would have been eligible for thrombolysis were it not for delays in symptom recognition. The delay to groin puncture exceeded 3 hours for over half of patients with proximal anterior occlusions. Earlier detection using prophylactic monitoring devices has the potential to reduce this major impedance to stroke care and ultimately improve outcomes.

Single molecule distribution of RhD binding epitopes on ultraflat erythrocyte ghosts

The Rh blood group system plays a key role in transfusion and organ transplant medicine. AFM-based recognition imaging on ulraflat erythrocyte ghost makes it possible to determine the molecular distribution of Rh epitopes over the entire erythrocyte.

AFM-Based Force Spectroscopy Guided by Recognition Imaging: A New Mode for Mapping and Studying Interaction Sites at Low Lateral Density

Ligand binding to receptors is one of the most important regulatory elements in biology as it is the initiating step in signaling pathways and cascades. Thus, precisely localizing binding sites and measuring interaction forces between cognate receptor–ligand pairs leads to new insights into the molecular recognition involved in these processes. Here we present a detailed protocol about applying a technique, which combines atomic force microscopy (AFM)-based recognition imaging and force spectroscopy for studying the interaction between (membrane) receptors and ligands on the single molecule level. This method allows for the selection of a single receptor molecule reconstituted into a supported lipid membrane at low density, with the subsequent quantification of the receptor–ligand unbinding force. Based on AFM tapping mode, a cantilever tip carrying a ligand molecule is oscillated across a membrane. Topography and recognition images of reconstituted receptors are recorded simultaneously by analyzing the downward and upward parts of the oscillation, respectively. Functional receptor molecules are selected from the recognition image with nanometer resolution before the AFM is switched to the force spectroscopy mode, using positional feedback control. The combined mode allows for dynamic force probing on different pre-selected molecules. This strategy results in higher throughput when compared with force mapping. Applied to two different receptor–ligand pairs, we validated the presented new mode.