Racial differences in P2Y12 inhibitor responsiveness in patients undergoing neuro-endovascular procedures: A cohort from the Middle East

BACKGROUND

Data on P2Y12 inhibitors responsiveness from the middle east is scarce. We sought to investigate patient responsiveness to P2Y12 inhibitors within a cohort of major races that characterize the UAE population. The secondary objective was to assess risk factors for hyper and hypo-responsiveness in this population.

METHODS

We conducted a cross-sectional study on adults who received either clopidogrel or ticagrelor treatments and had platelet responsiveness testing before undergoing neuro-endovascular interventions at our quaternary care hospital between March 2015 and April 2019.

RESULTS

During the study period, 249 subjects met the inclusion criteria. Overall, 17.3 % were hyper-responsive and 25.7 % were hypo-responsive to P2Y12 inhibitors. When comparing between the P2Y12 inhibitors, rates of hyper-responsiveness were significantly higher to ticagrelor when compared to clopidogrel (11 versus 6 %, p = 0.02 respectively). Contrarily, hypo-responsiveness rates were significantly higher in clopidogrel treated patients compared to their ticagrelor treated counterparts (23 versus 2 %, p < .001 respectively). Patients of Middle-Eastern origin showed a significantly higher rate of hypo-responsiveness to both clopidogrel and ticagrelor when compared to other races (41.1 % and 26.7 %, P < 0.001 respectively). Asians showed the highest rates of hyper-responsiveness for both agents. Multivariate logistic regression analysis showed that proton pump inhibitors and statin combination, (OR: 6.39, 95 %CI [1.60, 25.392]), and Middle East vs. Indian subcontinent patients (OR: 4.67, 95 %CI [1.79-12.14]) were independent predictors of hypo-responsiveness to both P2Y12 inhibitors.

CONCLUSION

This study demonstrated a high rate of hypo-responsiveness to P2Y12 inhibitors in a UAE cohort of patients undergoing neuro-endovascular procedures. In addition, therapeutic responsiveness to P2Y12 inhibitors varied markedly based on the racial background. Future larger studies are needed to evaluate genetic variations that may contribute to this rate of hypo-responsiveness in our population.

Development and validation of a parsimonious prediction model for positive urine cultures in outpatient visits

Urine culture is often considered the gold standard for detecting the presence of bacteria in the urine. Since culture is expensive and often requires 24-48 hours, clinicians often rely on urine dipstick test, which is considerably cheaper than culture and provides instant results. Despite its ease of use, urine dipstick test may lack sensitivity and specificity. In this paper, we use a real-world dataset consisting of 17,572 outpatient encounters who underwent urine cultures, collected between 2015 and 2021 at a large multi-specialty hospital in Abu Dhabi, United Arab Emirates. We develop and evaluate a simple parsimonious prediction model for positive urine cultures based on a minimal input set of ten features selected from the patient's presenting vital signs, history, and dipstick results. In a test set of 5,339 encounters, the parsimonious model achieves an area under the receiver operating characteristic curve (AUROC) of 0.828 (95% CI: 0.810-0.844) for predicting a bacterial count ≥ 105 CFU/ml, outperforming a model that uses dipstick features only that achieves an AUROC of 0.786 (95% CI: 0.769-0.806). Our proposed model can be easily deployed at point-of-care, highlighting its value in improving the efficiency of clinical workflows, especially in low-resource settings.

Clinical characteristics and admission patterns of stroke patients during the COVID 19 pandemic: A single center retrospective, observational study from the Abu Dhabi, United Arab Emirates

OBJECTIVE

To compare ischemic and hemorrhagic stroke patients with COVID-19 to non-COVID-19 controls, and to describe changes in stroke admission patterns during the pandemic.

METHODS

This is a single center, retrospective, observational study. All consecutive patients admitted with primary diagnosis of ischemic/ hemorrhagic stroke between March1st -May10th 2020 were included and compared with the same time period in 2019.

RESULTS

There was a 41.9% increase in stroke admissions in 2020 (148 vs 210,P = .001). When comparing all ischemic strokes, higher rate of large vessel occlusion (LVO) (18.3% vs 33.8%,P = .008) and significant delay in initiation of mechanical thrombectomy after hospital arrival (67.75 vs 104.30 minutes,P = .001) was observed in 2020. When comparing all hemorrhagic strokes, there were no differences between the two years. Among 591 COVID-19 admissions, 31 (5.24%) patients with stroke including 19 with ischemic (3.21%) and 12 with hemorrhagic stroke (2.03%) were identified. Patients with COVID-19 and ischemic stroke were significantly younger (58.74 vs 48.11 years,P = .002), predominantly male (68.18% vs 94.74%,P = .016), had lesser vascular risk factors, had more severe clinical presentation (NIHSS 7.01 vs 17.05,P < .001), and higher rate of LVO (23.6% vs. 63.1%,P = .006). There was no difference in the rate of endovascular thrombectomy, but time to groin puncture was significantly longer in COVID-19 patients (83.41 vs 129.50 minutes,P = .003). For hemorrhagic stroke, COVID-19 patients did not differ from non-COVID-19 patients.

CONCLUSIONS

Stroke continues to occur during this pandemic and stroke pathways have been affected by the pandemic. Stroke occurs in approximately 5% of patients with COVID-19. COVID-19 associated ischemic stroke occurs in predominantly male patients who are younger, with fewer vascular risk factors, can be more severe, and have higher rates of LVO. Despite an increase in LVO during the pandemic, treatment with mechanical thrombectomy has not increased. COVID-19 associated hemorrhagic stroke does not differ from non-COVID-19 hemorrhagic stroke patients.

SAT-443 Impact of Fasting on Plasma Thyrotropin in Hypothyroid Patients Taking Levothyroxine During Ramadan (IFT-R Study)

Background and Aim: We previously showed in a retrospective analysis that the plasma TSH rises significantly post-Ramadan in levothyroxine-treated hypothyroid patients, possibly as a result of changes in the eating habit during the non-fasting period from dusk until dawn. The aim of this study is to determine the best time for taking levothyroxine during Ramadan in order to minimize changes in thyroid function tests.

Methods: in a randomized prospective design, hypothyroid patients taking levothyroxine for greater than 6-months were randomized to take levothyroxine at one of the following 3 times during Ramadan: (group 1) at dusk after a prolonged fast and 30-minutes before the Iftar meal, (group 2) ≥ 3-hours after the Iftar meal, or (group 3) at dawn 30-minutes before Suhur meal. Patients were instructed to allow a minimum of 3-hours between the last meal and levothyroxine and to refrain from eating and drinking for at least 30-minutes after taking levothyroxine. Thyroid function tests were performed within 3-months before Ramadan and within 6-weeks post Ramadan. To estimate intent-to-treat effects, we examined pre- and post-Ramadan thyroid function tests in relation to the assigned levothyroxine administration times.

Results: 147 patients were randomized into the study and the respective number of patients in groups 1, 2 and 3 were 50, 46 and 51. The mean age of participants was 43.5±12.4 years [range 21.0-86.0] and 78% were females with no statistical differences in the mean age or gender distribution between the 3 groups. The respective pre-Ramadan mean TSH values for the 3 groups were 2.49 mIU/L, 2.16 mIU/L and 3.37 mIU/L with no significant differences at baseline. Post-Ramadan mean TSH values were 2.47 mIU/L, 4.26 mIU/L and 3.85 mIU/L for groups 1, 2 and 3 respectively. The pre- and post-Ramadan mean TSH differences were significant only for group 2, who took levothyroxine 3-hours post-Iftar (P-value 0.041). There were no significant differences in the free-T4 levels across the 3-groups before and after Ramadan. In a subset of 85 patients, the preferred times for levothyroxine administration during Ramadan were 44.7% before Iftar, 50.6% post-Iftar and only 4.7% were in favor of taking the medication before Suhur meal.

Conclusions: Levothyroxine-treated hypothyroid patients who took levothyroxine 3-hours after the main Iftar meal showed a significant increase in plasma TSH post-Ramadan, possibly reflecting a reduced time period between levothyroxine administration and the previous meal. There was no significant change in the mean plasma TSH for patients taking levothyroxine at dusk before Iftar or at dawn before Suhur. The least patient-preferred time for taking levothyroxine was at dawn before Suhur possibly due to time constraints before the start of fasting.

Dynamic variation of the axillary veins due to intrathoracic pressure changes: A prospective sonographic study

INTRODUCTION

The ultrasound-guided axillary vein is becoming a compulsory alternative vessel for central venous catheterization and the anatomical position offers several potential advantages over blind, subclavian vein techniques.

OBJECTIVE

To determine the degree of dynamic variation of the axillary vein size measured by ultrasound prior to the induction of general anesthesia and after starting controlled mechanical ventilation.

DESIGN

Prospective, observational study.

METHODS

One hundred ten patients undergoing elective surgery were enrolled and classified according to sex, age, and body mass index. Two-dimensional cross-sectional vein diameter, area, and mean flow velocity were performed using ultrasound on both the left and right axillary veins of each subject before and after induction of anesthesia.

RESULTS

There was statistically significant evidence showing that the axillary vein area increases when patients are mechanically ventilated. When considering venous flow velocity as a primary outcome, velocity decreased after patients moved from spontaneous to mechanical ventilation (coefficient = -0.267), but this relationship failed to achieve statistical significance (t = -1.355, p = 0.179).

CONCLUSIONS

Anatomical variations in depth and diameter as well as the collapsibility due to intrathoracic pressures changes represent common challenges that face clinicians during central venous catheterization of the axillary vein. A noteworthy increase in vessel size as patients transition from spontaneous to mechanical ventilation may theoretically improve first-pass cannulation success with practitioners skilled in both ultrasound and procedure. As a result, placing a centrally inserted central catheter after the induction of anesthesia may be beneficial.