AHA Highlights Four Studies That Provide Global Snapshots of Stroke Treatment During COVID-19

May 21, 2020—The American Heart Association (AHA) announced the publication of four separate studies in Stroke that indicate that the rate of strokes in COVID-19 patients appears relatively low, but a higher proportion of those strokes are presenting in younger people and are often more severe compared with strokes in people who do not have the novel coronavirus. At the same time globally, rates for stroke hospitalizations and treatments are significantly lower than for the first part of 2019.

As summarized in the AHA announcement, the four studies are:

• “Delays in Stroke Onset to Hospital Arrival Time during COVID-19” by Kay Cheong Teo, MBBS, et al, which evaluated stroke-onset time to hospital-arrival time for stroke and transient ischemic attack (TIA) patients from January 23 to March 24, 2020 compared to the same time period in 2019.
• “The Impact of the COVID-19 Epidemic on Stroke Care and Potential Solutions” by Jing Zhao, MD, et al. The investigators reported detailed survey results from > 200 stroke centers through the Big Data Observatory Platform for Stroke of China, which consists of 280 hospitals across China.
• “Mechanical Thrombectomy for Acute Ischemic Stroke Amid the COVID-19 Outbreak” by Basile Kerleroux, MD, et al that compared patient data from stroke centers across France from February 15 through March 30, 2020 versus data of patients treated during the same time period in 2019.
• "SARS2-CoV-2 and Stroke in a New York Healthcare System" by Shadi Yaghi, MD, et al. The investigators reported key demographic and clinical characteristics of patients who developed ischemic stroke associated with the COVID-19 infection and received care within one hospital system serving all five boroughs of New York, New York, during the study period of March 15 through April 19, 2020. Findings from this study were concurrently announced by the investigators from NYU Langone Health and covered in Endovascular Today.

The four studies report similar trends that reflect a global disruption of emergency health care services including delayed care and a lower-than-usual volume of stroke emergencies during the COVID-19 pandemic crisis, stated the AHA.

The Hong Kong study by Dr. Teo et al compared the stroke-onset time with hospital-arrival time in the first 60 days from the first diagnosed COVID-19 case in Hong Kong to the same time period in the previous year.

In 2020 compared with 2019:

• The number of stroke patients presented at Queen Mary Hospital decreased (73 vs 83)
• The stroke onset-to-arrival time was increased (154 vs 95 minutes)
• The number of patients arriving within the critical 4.5-hour treatment window decreased (55% vs 72%)

In the China study, Dr. Zhao et al found that in February 2020 versus the same time period in 2019, hospital admissions related to stroke dropped approximately 40%, and clot-busting treatment and mechanical clot-removal cases decreased by 25%.

The investigators cited several factors that likely contributed to the reduced admissions and prehospital delays during the COVID-19 pandemic, including lack of stroke knowledge and proper transportation. They also noted that another key factor was patients not coming to the hospital for fear of virus infection.

In France, Dr. Kerleroux et al found a 21% decrease in overall volume of ischemic patients receiving mechanical thrombectomy during the 2020 pandemic compared with the previous year (668 vs 844). Additionally, there was a significant increase in the amount of time from imaging to treatment overall (145 vs 126 minutes), and that delay increased by approximately 30 minutes in patients transferred to other facilities for treatment after imaging.

As reported in the AHA announcement, the investigators said delays may have been caused by unprecedented stress on emergency medical system services, and by primary care stroke centers lacking the transfer resources needed to send eligible patients to thrombectomy-capable stroke centers within the therapeutic window. Additionally, they noted stricter applications of guidelines during the pandemic period could also have meant some patients may have not been referred or accepted for mechanical thrombectomy treatment during that time.

Finally, in the New York study conducted March 15 to April 19, the investigators reviewed 3,556 hospitalized patients with a diagnosis of COVID-19 infection and identified 32 (0.9%) patients who had imaging-proven ischemic stroke.

The 32 patients admitted with stroke and COVID-19 were compared with those admitted only with stroke (46 patients). The investigators found that stroke patients with COVID-19 versus non-COVID patients, respectively:

• Were younger (average age, 63 vs 70 years)
• Had more severe strokes (average score on the National Institutes of Health Stroke Scale, 19 vs 8)
• Had higher D-dimer levels (10,000 vs 525)
• Were more likely to be treated with blood thinners (75% vs 23.9%)
• Were more likely to have a cryptogenic stroke (65.6% vs 30.4%)
• Were more likely to be dead at hospital discharge (63.6% vs 9.3%)

Conversely, COVID-19 stroke patients were less likely than those stroke patients without the virus to have high blood pressure (56.3% vs 76.1%) or to have a previous history of stroke (3.1% vs 13%).

The investigators observed that the rate of imaging-confirmed acute ischemic stroke in hospitalized patients with COVID-19 in their New York City hospital system (NYU Langone) was lower compared with previous reports in COVID-19 studies from China. One reason for the difference might be related to variations in race/ethnicity between the two study populations.
In addition, the low rate of ischemic stroke with COVID-19 infection may be underestimated because, as Dr. Yaghi stated, “The diagnosis of ischemic stroke can be challenging in those critically ill with COVID-19 infection who are intubated and sedated.”

In the AHA announcement, Dr. Yaghi commented further, “It was difficult to determine the exact cause of the strokes of the COVID-19 patients, however, most patients appeared to experience abnormal blood clotting. Additional research is needed to determine if therapeutic anticoagulation for stroke is useful in patients with COVID-19.”

The investigators noted that at least one clinical trial is already underway to investigate the safety and efficacy of treatment for active clotting versus preventive treatment in certain patients with COVID-19 infection presenting with possible clotting indicators.

Dr. Yaghi and colleagues also noted that the number of stroke cases with COVID-19 seems to have peaked and is now decreasing. This finding may be related to the overall reduction in COVID-19 hospital admissions, which may be the result of social distancing and guidance for people to stay at home. In addition, the number of stroke patients hospitalized during the study period was significantly lower than the same time frame in 2019, advised the AHA.