Meta-analysis: Stroke Response Times Early in COVID-19 Depended on Metric, Type of Center

Elderly man in wheelchair in front of hospital windows, with female nurse wearing mask and gloves

Delays in stroke treatment were inevitable during the early months of the COVID-19 epidemic, given virus-related precautions and the massive influx of COVID-19 patients into hospitals. Understanding the precise extent of those delays is important to learn what factors lead to late care and whether they are under physicians’ control.

Based on a systematic literature review and meta-analysis, researchers at Brigham and Women’s Hospital performed a systematic review of the literature and found 38 studies for meta-analysis. Each study compared at least one stroke care time metric between a COVID-19 period and a pre–COVID-19 period.

Mohammad Ali Aziz-Sultan, MD, MBA, chief of vascular/endovascular neurosurgery in the Department of Neurosurgery, Noah L. A. Nawabi, a research fellow in the department, and colleagues found significant delays in last-known-well to arrival time, which influenced door-to-reperfusion times, especially in comprehensive stroke centers (CSCs). In contrast, as they report in the Journal of NeuroInterventional Surgery, early efforts to adapt acute stroke treatment processes kept intrahospital stroke response times close to pre-pandemic levels.

Study Characteristics

A wide range of countries was represented in the analysis:

  • The U.S. and China each had nine studies included
  • Australia, Canada, Italy, Spain, and the U.K. all had at least two studies
  • Egypt, France, Iran, the Netherlands, Singapore, and the United Arab Emirates had one study each

14,637 patients presented with stroke during the various pre–COVID-19 periods studied and only 6,109 in the COVID-19 periods, a reduction of almost 60%.

27 studies included a CSC. In a subgroup analysis, the Brigham researchers stratified results by stroke center status (comprehensive or non-comprehensive).

Time Metrics Meta-analysis

On all metrics in the pooled analysis, there were delays in the COVID-19 periods studied compared with pre–COVID-19 periods. The most pronounced delays were in last-known-well (LWK) to arrival time and door to reperfusion time. In the following list, results without P-values were not statistically significant:

LWK to arrival

  • Overall—21% mean increased time during the pandemic vs. pre–COVID-19 periods (P=0.01)
  • Stratified—24% mean increased time at CSCs vs. 12% at non-CSCs

Door to imaging (DTI)

  • Overall—1.2%
  • Stratified—1.6% vs. 0.2%

Door to needle (DTN)

  • Overall—0.8%
  • Stratified—3.6% vs. −4.6% (a negative value indicates the decreased time during COVID-19) (P=0.04)

Door to groin (DTG)

  • Overall—2.8%
  • Stratified—4.6% vs. −0.6%

Door to reperfusion (DTR)

  • Overall—20% (P=0.00)
  • Stratified—21% vs. 0.5%

Explaining the Overall Findings

23 studies attributed delays in hospital presentation to shelter-in-place advisories and/or patient fear of exposure to COVID-19 in a hospital. 13 studies noted that stressed hospital and emergency medical transport systems were other potential reasons for delays.

Delays were far less pronounced for most intrahospital metrics, where physicians have more autonomy. Across studies, the good DTI, DTN, and DTG results were attributed to precautions such as COVID-19 symptom screening, additional requirements for personal protective equipment, and hospital isolation policies.

The mean 20% increase in DTR underscores that mechanical thrombectomy requires more time. Given the significant increase in LKW to arrival time, it’s possible thrombi became more solidified and were thus harder to clear, another dangerous potential implication of delayed presentation.

Explaining the Stratified Findings

Contrary to expectations, CSCs experienced more pronounced delays than non-CSCs early in the pandemic. Two groups of authors speculated that CSCs experienced a disproportionate influx in stroke cases as smaller centers nearby stopped taking stroke patients to care for COVID-19 patients. In addition, stroke patients who delayed care may have been more likely to have serious symptoms and need a referral to a CSC.

It’s hoped the information from this study will allow all stroke centers to optimize their workflow during the remainder of the pandemic and any future public health disasters.

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