Left atrial strain, embolic stroke of undetermined source, and atrial fibrillation detection.

BACKGROUND: Atrial cardiopathy is a proposed mechanism of embolic stroke of undetermined source (ESUS). Left atrial (LA) strain may identify early atrial cardiopathy prior to structural changes. We aim to study the associations between LA strain, ESUS, and atrial fibrillation (AF) detection in ESUS. METHODS: The study population included patients with ESUS and noncardioembolic (NCE) stroke presenting to the Rhode Island Hospital Stroke Center between January 2016 and June 2017 who underwent transthoracic echocardiography. Speckle tracking echocardiography (STE) was used to measure the three phases of LA strain (reservoir, conduit, and contractile). Binary logistic regression analysis was performed to determine the associations between LA strain and stroke subtype (ESUS vs. NCE) as well as follow-up detection of AF in ESUS patients. RESULTS: We identified 656 patients, 307 with ESUS and 349 with NCE. In binary logistic regression, the lowest tertiles of LA reservoir (adjusted OR 1.944, 95% CI 1.266-2.986, p = .002), contractile (aOR 1.568, 95% CI 1.035-2.374, p = .034), and conduit strain (aOR 2.288, 95% CI 1.448-3.613, p = .001) were more likely to be significantly associated with ESUS compared to NCE stroke. Among all ESUS patients, the lowest tertiles of LA reservoir strain (OR 2.534, 95% CI 1.029-6.236, p = .043), contractile strain (OR 2.828, 95% CI 1.158-6.903, p = .022), and conduit strain (OR 2.614, 95% CI 1.003-6.815, p = .049) were significantly associated with subsequent detection of AF. CONCLUSION: Reduced LA strain is associated with ESUS occurrence and AF detection in ESUS patients. Therefore, quantification of LA strain in ESUS patients may improve risk stratification and guide secondary prevention strategies.

A microfluidic double emulsion platform for spatiotemporal control of pH and particle synthesis.

The temporal control of pH in microreactors such as emulsion droplets plays a vital role in applications including biomineralisation and microparticle synthesis. Typically, pH changes are achieved either by passive diffusion of species into a droplet or by acid/base producing reactions. Here, we exploit an enzyme reaction combined with the properties of a water-oil-water (W/O/W) double emulsion to control the pH-time profile in the droplets. A microfluidic platform was used for production of ∼100-200 µm urease-encapsulated double emulsions with a tuneable mineral oil shell thickness of 10-40 µm. The reaction was initiated on-demand by addition of urea and a pulse in base (ammonia) up to pH 8 was observed in the droplets after a time lag of the order of minutes. The pH-time profile can be manipulated by the diffusion timescale of urea and ammonia through the oil layer, resulting in a steady state pH not observed in bulk reactive solutions. This approach may be used to regulate the formation of pH sensitive materials under mild conditions and, as a proof of concept, the reaction was coupled to calcium phosphate precipitation in the droplets. The oil shell thickness was varied to select for either brushite microplatelets or hydroxyapatite particles, compared to the mixture of different precipitates obtained in bulk.

Perioperative Acute Ischemic Stroke in Patients with Atrial Fibrillation.

OBJECTIVE: Anticoagulation therapy is commonly interrupted in patients with atrial fibrillation (AF) for elective procedures. However, the risk factors of acute ischemic stroke (AIS) during the periprocedural period remain uncertain. We performed a nationwide analysis to evaluate AIS risk factors in patients with AF undergoing elective surgical procedures. METHODS: Using the Nationwide Readmission Database, we included electively admitted adult patients with AF and procedural Diagnosis-Related Group codes from 2016 to 2019. Diagnoses were identified based on International Classification of Disease, 9th revision-Clinical Modification (ICD-10 CM) codes. We constructed a logistic regression model to identify risk factors and developed a new scoring system incorporating CHA2 DS2 VASc to estimate periprocedural AIS risk. RESULTS: Of the 1,045,293 patients with AF admitted for an elective procedure, the mean age was 71.5 years, 39.2% were women, and 0.70% had a perioperative AIS during the index admission or within 30 days of discharge. Active cancer (adjusted OR [aOR] = 1.58, 95% confidence interval [CI] = 1.42-1.76), renal failure (aOR = 1.14, 95% CI = 1.04-1.24), neurological surgery (aOR = 4.51, 95% CI = 3.84-5.30), cardiovascular surgery (aOR = 2.74, 95% CI = 2.52-2.97), and higher CHA2 DS2 VASc scores (aOR 1.25 per point, 95% CI 1.22-1.29) were significant risk factors for periprocedural AIS. The new scoring system (area under the receiver operating characteristic curve [AUC] = 0.68, 95% CI = 0.67 to 0.79) incorporating surgical type and cancer outperformed CHA2 DS2 VASc (AUC = 0.60, 95% CI = 0.60 to 0.61). INTERPRETATION: In patients with AF, periprocedural AIS risk increases with the CHA2 DS2 VASc score, active cancer, and cardiovascular or neurological surgeries. Studies are needed to devise better strategies to mitigate perioperative AIS risk in these patients. ANN NEUROL 2023;94:321-329.

Pregnancy and Motherhood Challenges during Postgraduate Training in Pakistan.

In Pakistan, women have outnumbered men in medicine and many women now choose to start a family earlier in their careers. A 24-question survey was electronically distributed over social media. Female postgraduate trainees and consultants who had experienced pregnancy and motherhood during their training were included. Questions were asked about their experiences of pregnancy, news breaking, attitudes of colleagues and supervisors, maternity leaves, and lactational issues. A total of 320 responses were received; Internal Medicine (19.1%), Gynaecology and Obstetrics (15.0%), Surgery 46 (14.4%), and Pediatrics (11.9%) were major specialities. One hundred and nineteen (37.2%) respondents feared they would be considered 'uncommitted" if the news of their pregnancy broke. Breastfeeding was important to 77.5% mothers, but only 40% of the mothers could breastfeed, and 86.2% reported that lactation facilities were inadequate. 50% mothers thought to strongly reconsider their speciality. Postgraduate training programs in Pakistan should be tailored to address the needs of trainee mothers. Key Words: Motherhood, Postgraduate training, Lactation, Pregnancy.

Acute ischemic stroke on anti-Xa inhibitors: Pharmacokinetics and outcomes.

BACKGROUND AND PURPOSE: Direct oral anticoagulant (DOAC) ingestion within 48 h is an exclusion for thrombolysis in acute ischemic stroke (AIS) patients. We aim to shed light on pharmacokinetic correlates and outcomes in patients with AIS excluded from thrombolysis due to DOAC use. METHODS: This is a single center retrospective study of consecutive patients with AIS within 4.5 h from last known normal and excluded from thrombolytic therapy due to confirmed Xa inhibitor DOAC (DOACXa) intake within the prior 48 h. We used linear regression to test the correlation between time from last DOACXa ingestion and anti-Xa level. RESULTS: Over a period of 2.5 years, we identified 44 patients who did not receive thrombolysis because of presumed DOAC intake within 48 h. In adjusted linear regression, there was an association between time from last DOAC ingestion and Xa level (beta = -0.69, p < 0.001). Among the 37 patients with known atrial fibrillation not receiving alteplase due to DOAC use, the 90-day mortality was 35.1% (13/37) and 77% (10/13) of deaths were stroke related. CONCLUSIONS: Patients with AIS on DOAC therapy face a heightened risk of mortality. Studies are needed to investigate the safety and efficacy of thrombolysis in such patients based on time of last DOAC ingestion and/or anti-Xa/drug level.