Role of cardiac computed tomography in hyperacute stroke assessment.

BACKGROUND: Incorporating cardiac CT with hyperacute stroke imaging may increase the yield for cardioembolic sources. It is not clarified whether stroke severity influences on rates of intracardiac thrombus. We aimed to investigate a National Institutes of Health Stroke Scale (NIHSS) threshold below which acute cardiac CT was unnecessary. METHODS: Consecutive patients with suspected stroke who underwent multimodal brain imaging and concurrent non-gated cardiac CT with delayed timing were prospectively recruited from 1st December 2020 to 30th November 2021. We performed receiver operating characteristics analysis of the NIHSS and intracardiac thrombus on hyperacute cardiac CT. RESULTS: A total of 314 patients were assessed (median age 69 years, 61% male). Final diagnoses were ischemic stroke (n=205; 132 etiology-confirmed stroke, independent of cardiac CT and 73 cryptogenic), transient ischemic attack (TIA) (n=21) and stroke-mimic syndromes (n=88). The total yield of cardiac CT was 8 intracardiac thrombus and 1 dissection. Cardiac CT identified an intracardiac thrombus in 6 (4.5%) with etiology-confirmed stroke, 2 (2.7%) with cryptogenic stroke, and none in patients with TIA or stroke-mimic. All of those with intracardiac thrombus had NIHSS ≥4 and this was the threshold below which hyperacute cardiac CT was not justified (sensitivity 100%, specificity 38%, positive predictive value 4.0%, negative predictive value 100%). CONCLUSIONS: A cutoff NIHSS ≥4 may be useful to stratify patients for cardiac CT in the hyperacute stroke setting to optimize its diagnostic yield and reduce additional radiation exposure.

Transition in Incidence Rate of Hospitalised Stroke and Case Fatality Rate in the Hunter Region, Australia, 2001-2019: A Prospective Hospital-Based Study.

INTRODUCTION: Continuous surveillance of stroke admissions has been conducted in the Hunter region, Australia, over the past two decades. We aimed to describe the trends in incidence rates of hospitalised stroke and case-fatality rates in this region, 2001-2019. METHODS: From a hospital-based stroke registry, data for admitted adult stroke patients residing in the Hunter region were collected using ICD-10 codes for ischemic and haemorrhagic stroke. Negative binomial regression and logistic regression analysis were used to analyse trends for age-standardised and age-specific incidence rates of hospitalised stroke and 28-day case-fatality rates. RESULTS: A total of 14,662 hospitalisations for stroke in 13,242 individuals were registered. The age-standardised incidence rate declined from 123 per 100,000 population in the 2001-2005 epoch to 96 in the 2016-2019 epoch (mean annual change -2.0%, incidence rate ratio (IRR) = 0.980 [95%CI: 0.976-0.984]). Age-specific analyses identified significant reduction in the group aged 75-84 (1039 per 100,000 population in 2001-2005 to 633 in 2016-2019, annual change -3.5%, IRR= 0.965 [95%CI: 0.960-0.970]). The 28-day case-fatality rates fluctuated over time (18.5% in 2001-2005, 20.8% in 2010-2015, and 17.8% in 2016-2019).  Projected population aging suggests annual volume of patients with new stroke will increase by 77% by 2041 if incidence rates remain unchanged at the 2016-2019 level. CONCLUSION: Although age-standardised hospitalised stroke incidence rates have declined in the Hunter region, the health system will face an increase in stroke hospitalisations related to the aging population.

Ischemic Lesion Growth in Patients with a Persistent Target Mismatch After Large Vessel Occlusion.

BACKGROUND: Failure to reperfuse a cerebral occlusion resulting in a persistent penumbral pattern has not been fully described. METHODS: We retrospectively reviewed patients with anterior large vessel occlusion who did not receive reperfusion, and underwent repeated perfusion imaging, with baseline imaging < 6 h after onset and follow-up scans from 16-168 h. A persistent target mismatch (PTM) was defined as core volume of < 100 mL, mismatch ratio > 1.2, and mismatch volume > 10 mL on follow-up imaging. Patients were divided into PTM or non-PTM groups. Ischemic core and penumbral volumes were compared between baseline and follow-up imaging between the two groups, and collateral flow status assessed using CT perfusion collateral index. RESULTS: A total of 25 patients (14 PTM and 11 non-PTM) were enrolled in the study. Median core volumes increased slightly in the PTM group, from 22 to 36 ml. There was a much greater increase in the non-PTM group, from 57 to 190 ml. Penumbral volumes were stable in the PTM group from a median of 79 ml at baseline to 88 ml at follow-up, whereas penumbra was reduced in the non-PTM group, from 120 to 0 ml. Collateral flow status was also better in the PTM group and the median collateral index was 33% compared with 44% in the non-PTM group (p = 0.043). CONCLUSION: Multiple patients were identified with limited core growth and large penumbra (persistent target mismatch) > 16 h after stroke onset, likely due to more favorable collateral flow.

The Need for Structured Strategies to Improve Stroke Care in a Rural Telestroke Network in Northern New South Wales, Australia: An Observational Study.

Introduction: A telestroke network in Northern New South Wales, Australia has been developed since 2017. We theorized that the telestroke network development would drive a progressive improvement in stroke care metrics over time. Aim: This study aimed to describe changes in acute stroke workflow metrics over time to determine whether they improved with network experience. Methods: We prospectively collected data of patients assessed by telestroke who received multimodal computed tomography (mCT) and were diagnosed with ischemic stroke or transient ischemic attack from January 2017 to July 2019. The period was divided into two phases (phase 1: January 2017 - October 2018 and phase 2: November 2018 - July 2019). We compared median door-to-call, door-to-image, and door-to-decision time between the two phases. Results: We included 433 patients (243 in phase 1 and 190 in phase 2). Each spoke site treated 1.5-5.2 patients per month. There were Door-to-call time (median 39 in phase 1, 35 min in phase 2, p = 0.18), and door-to-decision time (median 81.5 vs. 83 min, p = 0.31) were not improved significantly. Similarly, in the reperfusion therapy subgroup, door-to-call time (median 29 vs. 24.5 min, p = 0.12) and door-to-decision time (median 70.5 vs. 67.5 min, p = 0.75) remained substantially unchanged. Regression analysis showed no association between time in the network and door-to-decision time (coefficient 1.5, p = 0.32). Conclusion: In our telestroke network, acute stroke timing metrics did not improve over time. There is the need for targeted education and training focusing on both stroke reperfusion competencies and the technical aspects of telestroke in areas with limited workforce and high turnover.