Introduction: Information on stroke mortality in people residing at high altitudes is controversial, and during the coronavirus disease 2019 (COVID-19) pandemic, there was a decrease in in-person care. Our objective is to evaluate mortality and functional prognosis after 3 months in stroke patients residing at high altitude during the COVID-19 pandemic. Methods: An analytical longitudinal study was conducted from January 2020 to January 2022 in a hospital in Cusco (3300 m above sea level), including adult patients diagnosed with stroke but without COVID-19 diagnosis, who were followed up for 90 days, evaluating mortality and functional disability (modified Rankin scale ≥ 3). Clinical and laboratory risk factors were evaluated, obtaining crude and adjusted hazard ratios (HR) through Cox regression models with 95% confidence intervals (CI95%). Results: One hundred twenty-three stroke patients were evaluated. After 90 days of follow-up, 28 patients (22.7%) died and 80 patients (65.0%) were diagnosed with functional disability. In models adjusted for gender, age, Alberta stroke program early CT (ASPECTS) score, and hypertension background, the only variable with increased risk was National Institutes of Health Stroke Scale (NIHSS) score at admission, both for mortality (HR 1.14, CI95% 1.09–1.20) and functional disability (HR 1.07, CI95% 1.04–1.11). Conclusions: Regarding stroke patients cared for in a high-altitude city during the COVID-19 pandemic, NIHSS score at admission is the most important risk factor for determining the 90-day mortality or functional disability, with a risk increase of approximately 10% for both outcomes for each additional point on the scale.
altitud
Alta viscosidad sanguínea en pacientes con Ictus Isquémico que residen a gran altitud. High blood viscosity in patients with ischemic stroke residing at high altitude.
Introduction: Risk factors for ischemic stroke have been extensively studied. However, few studies have been conducted in populations residing in high-altitude cities, where acclimatization processes cause elevations in blood viscosity. Our objective is to evaluate the association between blood viscosity and ischemic stroke in patients residing at altitude and to identify the most frequent subtype of ischemic stroke among these patients.
Methods: This case-control study was conducted in a hospital in Cusco, Peru (3,399 m) and included patients with and without ischemic stroke. Patients were included in the ischemic stroke group (cases) after having had up to three days of confirmed illness. The control group comprised patients hospitalized for other causes. Blood viscosity (in centipoise [cP]) was measured using a cone/plate viscometer. Viscosity data are reported as medians with interquartile ranges (IQR), and associations were evaluated using logistic regression with odds ratios (OR).
Results: A total of 386 patients were included, of which 141 (36.5%) had ischemic stroke. The median age was 67 years (IQR 52-80), and 165 (42.7%) patients were women. Blood viscosity was significantly higher in the ischemic stroke group (5.9 cP; IQR, 5.2–6.8) than in the control group (5.5 cP; IQR, 4.9–6.1; p<0.001). An increase in blood viscosity (in 1 cP increments) was associated with an increased risk of developing ischemic stroke (OR 1.40; 95% confidence interval, 1.16–1.69; p<0.001). Patients with the small-vessel occlusion subtype had the highest blood viscosity (6.1 cP; IQR, 5.8–6.3), which was significantly higher than in patients without stroke (p=0.002) or with other ischemic stroke subtypes (p=0.03).
Conclusions: Patients with ischemic stroke residing at high altitudes have higher blood viscosity than control patients regardless of ischemic stroke subtype, although the small-vessel occlusion subtype corresponded with the highest blood viscosity.
