Assessment of Mendelian and risk-factor genes in Alzheimer disease: A prospective nationwide clinical utility study and recommendations for genetic screening

PURPOSE

To assess the likely pathogenic/pathogenic (LP/P) variants rates in Mendelian dementia genes and the moderate-to-strong risk factors rates in patients with Alzheimer disease (AD).

METHODS

We included 700 patients in a prospective study and performed exome sequencing. A panel of 28 Mendelian and 6 risk-factor genes was interpreted and returned to patients. We built a framework for risk variant interpretation and risk gradation and assessed the detection rates among early-onset AD (EOAD, age of onset (AOO) ≤65 years, n = 608) depending on AOO and pedigree structure and late-onset AD (66 < AOO < 75, n = 92).

RESULTS

Twenty-one patients carried a LP/P variant in a Mendelian gene (all with EOAD, 3.4%), 20 of 21 affected APP, PSEN1, or PSEN2. LP/P variant detection rates in EOAD ranged from 1.7% to 11.6% based on AOO and pedigree structure. Risk factors were found in 69.5% of the remaining 679 patients, including 83 (12.2%) being heterozygotes for rare risk variants, in decreasing order of frequency, in TREM2, ABCA7, ATP8B4, SORL1, and ABCA1, including 5 heterozygotes for multiple rare risk variants, suggesting non-monogenic inheritance, even in some autosomal-dominant-like pedigrees.

CONCLUSION

We suggest that genetic screening should be proposed to all EOAD patients and should no longer be prioritized based on pedigree structure.

Is off-label thrombolysis safe and effective in a real-life primary stroke center? A retrospective analysis of data from a 5-year prospective database

BACKGROUND

Intravenous thrombolysis (IVT) use for acute ischemic stroke (AIS) varies among countries, partly due to guidelines and product labeling changes. The study aim was to identify the characteristics of patients with AIS treated with off-label IVT and to determine its safety when performed in a primary stroke center (PSC).

METHODS

This observational, single-center study included all consecutive patients admitted to Perpignan PSC for AIS and treated with IVT and patients transferred for EVT, between January 1, 2015 and December 31, 2019. Data of patients treated with IVT according to ("in-label group") or outside ("off-label") the initial guidelines and manufacturer's product specification were compared. Safety was assessed using symptomatic intracerebral hemorrhage (SIH) as the main adverse event.

RESULTS

Among the 892 patients in the database (834 screened by MRI, 93.5%), 746 were treated by IVT: 185 (24.8%) "in-label" and 561 (75.2%) "off-label". In the "off-label" group, 316 (42.4% of the cohort) had a single criterion for "off-label" use, 197 (26.4%) had two, and 48 (6.4%) had three or more criteria, without any difference in IVT safety pattern among them. SIH rates were comparable between the "off-label" and "in-label" groups (2.7% vs. 1.1%, P=0.21); early neurological deterioration and systematic adverse event due to IVT treatment were similar in the 2 groups. "Off-label" patients had higher in-hospital (8.7% vs. 3.8%, P=0.05) and 3-month mortality rates (12.1% vs 5.4%, P<0.01), but this is explained by confounding factors as they were older (76 vs 67 years, P<0.0001) and more dependent (median modified Rankin scale score 0.4 vs 0.1, P<0.0001) at admission.

CONCLUSIONS

"Off-label" thrombolysis for AIS seems to be safe and effective in the routine setting of a primary stroke center.

Endovascular treatment for acute ischemic stroke at a primary stroke center: First results of the Perpignan center

INTRODUCTION

Converting a high-volume primary stroke center (PSC) into a stroke center that can perform emergency endovascular treatment (EVT) could reduce the time to thrombectomy. We report the first results of a newly established EVT facility at the Perpignan PSC and their comparison with the targets defined by the established guidelines.

PATIENTS AND METHOD

For this comprehensive observational study, data of patients with acute ischemic stroke (AIS) due to proximal large vessel occlusion (LVO) and treated by EVT at the Perpignan PSC from December 5, 2019 to September 15, 2020 were extracted from an ongoing prospective database.

RESULTS

During the study period, 37 patients underwent EVT at the Perpignan PSC. The median (range) symptom-onset to recanalization time was 262min (100-485min). The median (range) intra-hospital times were: 20min (2-58min) for door-to-imaging, 57min (30-155min) for imaging-to-puncture, 55min (15-180min) for puncture-to-recanalization, and 137min (59-319min) for door-to-recanalization. At 3 months post-AIS, the favorable outcome (modified Ranking Score: 0-2) rate was 50% and the mortality rate was 19.4%. These results are comparable to those of previous clinical trials, and meet the targets defined by the current consensus statements for EVT.

DISCUSSION AND CONCLUSION

Our results show the feasibility and safety of EVT in a PSC for patients with AIS due to LVO. The implementation of this strategy may be important for shortening the time to thrombectomy.

Futile inter-hospital transfer for mechanical thrombectomy in a semi-rural context: analysis of a 6-year prospective registry

Background and purpose

Inter-hospital transfer for mechanical thrombectomy (MT) might result in the transfer of patients who finally will not undergo MT (ie, futile transfers [FT]). This study evaluated FT frequency in a primary stroke center (PSC) in a semi-rural area and at 156 km from the comprehensive stroke center (CSC).

Methodology

Retrospective analysis of data collected in a 6-year prospective registry concerning patients admitted to our PSC within 4.5 hours of acute ischemic stroke (AIS) symptom onset, with MR angiography indicating the presence of large vessel occlusion (LVO) without large cerebral infarction (DWI-ASPECT ≥5), and selected for transfer to the CSC to undergo MT. Futile transfer rate and reasons were determined, and the relevant time measures recorded.

Results

Among the 529 patients screened for MT, 278 (52.6%) were transferred to the CSC. Futile transfer rate was 45% (n=125/278) and the three main reasons for FT were: clinical improvement and reperfusion on MRI on arrival at the CSC (58.4% of FT); clinical worsening and/or infarct growth (16.8%); and longer than expected inter-hospital transfer time (11.2%). Predictive factors of FT due to clinical improvement/reperfusion on MRI could not be identified. Baseline higher NIHSS (21 vs 17; P=0.01) and lower DWI-ASPECT score (5 vs 7; P=0.001) were associated with FT due to clinical worsening/infarct growth on MRI.

Conclusions

In our setting, 45% of transfers for MT were futile. None of the baseline factors could predict FT, but the initial symptom severity was associated with FT caused byclinical worsening/infarct growth.

Target Door-to-Needle Time for Tissue Plasminogen Activator Treatment with Magnetic Resonance Imaging Screening Can Be Reduced to 45 min

Objective: The purpose of this study was to demonstrate that the median door-to-needle (DTN) time for intravenous tissue plasminogen activator (tPA) treatment can be reduced to 45 min in a primary stroke centre with MRI-based screening for acute ischaemic stroke (AIS). Methods: From February 2015 to February 2017, the stroke unit of Perpignan general hospital, France, implemented a quality-improvement (QI) process. During this period, patients who received tPA within 4.5 h after AIS onset were included in the QI cohort. Their clinical characteristics and timing metrics were compared each semester and also with those of 135 consecutive patients with AIS treated by tPA during the 1-year pre-QI period (pre-QI cohort). Results: In the QI cohort, 274 patients (92.5%) underwent MRI screening. While the demographic and baseline characteristics were not significantly different between cohorts, the median DTN time was significantly lower in the QI than in the pre-QI cohort (52 vs. 84 min; p < 0.00001). Within the QI cohort, the median DTN time for each semester decreased from 65 to 44 min (p < 0.00001) and the proportion of treated patients with a DTN time ≤45 min increased from 25 to 58.9% (p < 0.0001). Overall, DTN time improvement was associated with a better outcome at 3 months (patients with a modified Rankin Scale score between 0 and 2: 61.8% in the QI vs. 39.3% in the pre-QI cohort; p < 0.0001). Conclusions: A QI process can reduce the DTN within 45 min with MRI as a screening tool.

Results of a 1-year quality-improvement process to reduce door-to-needle time in acute ischemic stroke with MRI screening

OBJECTIVE

To determine the effects of a 1-year quality-improvement (QI) process to reduce door-to-needle (DTN) time in a secondary general hospital in which multimodal MRI screening is used before tissue plasminogen activator (tPA) administration in patients with acute ischemic stroke (AIS).

METHODS

The QI process was initiated in January 2015. Patients who received intravenous (iv) tPA<4.5h after AIS onset between 26 February 2015 to 25 February 2016 (during implementation of the QI process; the "2015 cohort") were identified (n=130), and their demographic and clinical characteristics and timing metrics compared with those of patients treated by iv tPA in 2014 (the "2014 cohort", n=135).

RESULTS

Of the 130 patients in the 2015 cohort, 120 (92.3%) of them were screened by MRI. The median DTN time was significantly reduced by 30% (from 84min in 2014 to 59min; P<0.003), while the proportion of treated patients with a DTN time≤60min increased from 21% to 52% (P<0.0001). Demographic and baseline characteristics did not significantly differ between cohorts, and the improvement in DTN time was associated with better outcomes after discharge (patients with a 0-2 score on the modified rankin scale: 59% in the 2015 cohort vs 42.4% in the 2014 cohort; P<0.01). During the 1-year QI process, the median DTN time decreased by 15% (from 65min in the first trimester to 55min in the last trimester; P≤0.04) with a non-significant 1.5-fold increase in the proportion of treated patients with a DTN time≤60min (from 41% to 62%; P=0.09).

CONCLUSION

It is feasible to deliver tPA to patients with AIS within 60min in a general hospital, using MRI as the routine screening modality, making this QI process to reduce DTN time widely applicable to other secondary general hospitals.