Stroke one of the strongest predictors of COVID-19 mortality

A territory-wide retrospective cohort study by the Chinese University of Hong Kong (CUHK) has found that stroke is the third strongest predictor of coronavirus disease 2019 (COVID-19) mortality, after advancing age and renal disease, while Parkinson’s disease (PD) was the second strongest predictor of death after advancing age during the severe acute respiratory syndrome (SARS) epidemic of 2003.

“Recent reports suggest that neurological diseases, in particular, stroke, dementia and advanced PD, are important predictors of COVID-19–related mortality. Given mortality rates and predictors may vary across regions, we investigated the impact of pre-existing neurological diseases on the mortality of patients with COVID-19 in Hong Kong,” wrote the researchers. [Nature 2020;584:430-436; Clin Neurol Neurosurg 2020;197:106183; Parkinsonism Relat Disord 2020;78:134-137. “The resulting data should provide important guidance on resource allocation and future healthcare policy.”

This territory-wide retrospective cohort study used data from the Clinical Data Analysis and Reporting System (CDARS), an electronic healthcare database that covers patients’ demographics, laboratory results, diagnoses, procedures, drug prescription and dispensing history, and death from all public hospitals and clinics in Hong Kong, where all patients with confirmed COVID-19 or SARS were hospitalized in the territory. [J Neurol Neurosurg Psychiatry 2021;92:1356-1358]

A total of 3,164 patients with COVID-19 were identified during the period of 23 January 2020 to 31 July 2020, and 1,670 patients with SARS were identified during March to June 2003. The overall case fatality rates of COVID-19 and SARS in the studied periods were 2.28 percent and 16.8 percent, respectively.

Multivariable analysis among patients with COVID-19 demonstrated that stroke (adjusted hazard ratio [aHR], 2.31; 95 percent confidence interval [CI], 1.35 to 3.96; p=0.002) was the third strongest predictor of mortality, after advancing age and renal diseases. According to multivariable analysis among SARS patients, PD was the second strongest predictor of death (aHR, 1.95; 95 percent CI, 1.05 to 3.64; p=0.035) after advancing age.

“The strong association between neurological diseases and mortality observed in our two separate cohorts may be because patients with neurological disability often require assistance from caregivers in performing daily activities; hence, physical distancing during the COVID-19 pandemic may not be feasible for them. The long duration of exposure to potentially infected caregivers may confer a higher viral load, leading to a higher mortality. Moreover, infected patients with neurological disabilities, especially those of older age, may have nonspecific symptoms or may be less able to communicate their discomforts, leading to a delay in diagnosis and management, resulting in higher mortality,” speculated the researchers.

“Both SARS and COVID-19 are associated with significant immune and inflammatory responses, and the resultant cytokine storm can be responsible for morbidity and mortality in susceptible hosts. The background neuroinflammation in patients with chronic neurological diseases could be exacerbated by the inflammatory response and cytokine storm induced by the coronavirus infection, accounting for worse outcomes,” they added.

In conclusion, the researchers recommended protective strategies, such as prioritized vaccination for patients with neurological disease and their caregivers and use of telemedicine.