Decline in mild stroke presentations and intravenous thrombolysis during the COVID-19 pandemic: The Society of Vascular and Interventional Neurology Multicenter Collaboration

Abstract

Background: To evaluate overall ischemic stroke volumes and rates, specific subtypes, and clinical presentation during the COVID-19 pandemic in a multicenter observational study from eight states across US.

Methods: We compared all ischemic strokes admitted between January 2019 and May 2020, grouped as; March-May 2020 (COVID-19 period) and March-May 2019 (seasonal pre-COVID-19 period). Primary outcome was stroke severity at admission measured by NIHSS stratified as mild (0-7), moderate [8-14], and severe (>14). Secondary outcomes were volume of large vessel occlusions (LVOs), stroke etiology, IV-tPA rates, and discharge disposition.

Results: Of the 7969 patients diagnosed with acute ischemic stroke during the study period, 933 (12 %) presented in the COVID-19 period while 1319 (17 %) presented in the seasonal pre-COVID-19 period. Significant decline was observed in the mean weekly volumes of newly diagnosed ischemic strokes (98 ± 3 vs 50 ± 20,p = 0.003), LVOs (16.5 ± 3.8 vs 8.3 ± 5.9,p = 0.008), and IV-tPA (10.9 ± 3.4 vs 5.3 ± 2.9,p = 0.0047), whereas the mean weekly proportion of LVOs (18 % ±5 vs 16 % ±7,p = 0.24) and IV-tPA (10.4 % ±4.5 vs. 9.9 % ±2.4,p = 0.66) remained the same, when compared to the seasonal pre-COVID-19 period. Additionally, an increased proportion of patients presented with a severe disease (NIHSS > 14) during the COVID-19 period (29.7 % vs 24.5 %,p < 0.025). The odds of being discharged to home were 26 % greater in the COVID-19 period when compared to seasonal pre-COVID-19 period (OR:1.26, 95 % CI:1.07-1.49,p = 0.016).

Conclusions: During COVID-19 period there was a decrease in volume of newly diagnosed ischemic stroke cases and IV-tPA administration. Patients admitted to the hospital had severe neurological clinical presentation and were more likely to discharge home.

Keywords: COVID-19; Coronavirus; Ischemic stroke; Large vessel occlusion; NIHSS.

Fig. 1

Admission NIHSS by study periods. Stroke severity measured by NIHSS stratifies as 3-levels, with scores of 0−7 being classified as “mild” symptoms, 8−14 as “moderate”, and >14 as “severe”. 12-weeks epochs include; COVID-19 period: 03/01/2020–05/31/2020, seasonal pre-COVID-19 period: 03/01/2019–05/31/2019 and immediate pre-COVID-19 period: 11/01/2019–01/31/2020. NIHSS: National Institute of Health Stroke Scale. UpOR = Unadjusted proportional odds ratio.

Fig. 2

Etiology of stroke by study periods. Criteria stratified by the Trial of Org 10172 for Acute Stroke Treatment. 12-weeks epochs include; COVID-19 period: 03/01/2020–05/31/2020, seasonal pre-COVID-19 period: 03/01/2019–05/31/2019 and immediate pre-COVID-19 period: 11/01/2019–01/31/2020.

Fig. 3

Weekly new stroke cases during the study periods. Shown are weekly event rates for new acute ischemic stroke diagnoses (blue diamonds), large vessel occlusions (green bubbles), and treatment rate with intravenous thrombolysis (red triangles). Periods highlighted in blue and red indicate the 12-week periods which were used for t-test comparisons, as described in the Methods. Blue, green, and red bars indicate mean event rates during each red or blue study periods. IV-tPA denotes intravenous tissue plasminogen activator and LVO large vessel occlusion. 12-weeks epochs include; COVID-19 period: 03/01/2020–05/31/2020, seasonal pre-COVID-19 period: 03/01/2019–05/31/2019 and immediate pre-COVID-19 period: 11/01/2019–01/31/2020.