COVID-19 Stroke Apical Lung Examination Study: A Diagnostic and Prognostic Imaging Biomarker in Suspected Acute Stroke.

BACKGROUND AND PURPOSE: Diagnosis of coronavirus disease 2019 (COVID-19) relies on clinical features and reverse-transcriptase polymerase chain reaction testing, but the sensitivity is limited. Carotid CTA is a routine acute stroke investigation and includes the lung apices. We evaluated CTA as a potential COVID-19 diagnostic imaging biomarker. MATERIALS AND METHODS: This was a multicenter, retrospective study (n = 225) including CTAs of patients with suspected acute stroke from 3 hyperacute stroke units (March-April 2020). We evaluated the reliability and accuracy of candidate diagnostic imaging biomarkers. Demographics, clinical features, and risk factors for COVID-19 and stroke were analyzed using univariate and multivariate statistics. RESULTS: Apical ground-glass opacification was present in 22.2% (50/225) of patients. Ground-glass opacification had high interrater reliability (Fleiss κ = 0.81; 95% CI, 0.68-0.95) and, compared with reverse-transcriptase polymerase chain reaction, had good diagnostic performance (sensitivity, 75% [95% CI, 56-87]; specificity, 81% [95% CI, 71-88]; OR = 11.65 [95% CI, 4.14-32.78]; P < .001) on multivariate analysis. In contrast, all other contemporaneous demographic, clinical, and imaging features available at CTA were not diagnostic for COVID-19. The presence of apical ground-glass opacification was an independent predictor of increased 30-day mortality (18.0% versus 5.7%, P = .017; hazard ratio = 3.51; 95% CI, 1.42-8.66; P = .006). CONCLUSIONS: We identified a simple, reliable, and accurate COVID-19 diagnostic and prognostic imaging biomarker obtained from CTA lung apices: the presence or absence of ground-glass opacification. Our findings have important implications in the management of patients presenting with suspected stroke through early identification of COVID-19 and the subsequent limitation of disease transmission.

Genetic polymorphisms of human ß-defensins in patients with ischemic stroke.

OBJECTIVES AND METHODS: Genetic predisposition of the inflammatory host response may affect the development of stroke. On the basis of the theory of infectious burden and risk of stroke, we considered it of interest to investigate the relevance of the single-nucleotide polymorphisms (SNPs) in the DEFB1 gene and the copy number variant (CNV) of the DEFB4 genes in ischemic stroke. RESULTS: There were no significant differences in the genotype frequencies of the three SNPs of the DEFB1 gene between the patients with stroke (n = 312) and the healthy blood donors (n = 221). However, a higher frequency of a lower (<4) copy number of the DEFB4 gene was observed in the patients with ischemic stroke as compared with the healthy controls (40% vs 24%, respectively). Additionally, low plasma concentrations of hBD-2 (187 ± 20 pg/ml) were characteristic of the patients with fewer than four copy numbers relative to those with more than four copy numbers (385 ± 35 pg/ml). CONCLUSIONS: The low copy number of the DEFB4 gene, involving a weakened antimicrobial defense of the host, might be important in the pathogenesis of stroke.

Relevance of the genetic polymorphism of NOD1 in Chlamydia pneumoniae seropositive stroke patients.

BACKGROUND AND PURPOSE: Chronic infections with certain pathogens, such as Chlamydia pneumoniae, and genetic parameters that influence inflammatory reactions have been suggested to contribute to ischaemic stroke. NOD1 is a potent cytosolic receptor for C. pneumoniae. The aim of this study was to investigate the genetic polymorphism of NOD1 from the aspect of the development of stroke. MATERIALS AND METHODS: A total of 280 patients with ischaemic stroke were enrolled in the study; 150 healthy blood donors served as controls. The G796A (E266K) NOD1 polymorphism was determined by restriction fragment length polymorphism. Chlamydia pneumoniae seropositivity was tested by ELISA. RESULTS: There was a significant difference in NOD1 G796A genotype distribution between the controls and the stroke patients with C. pneumoniae seropositivity. The AA homozygote and GA heterozygote mutant variants were detected in 16% (25 of 152) and in 50% (77 of 152) of the C. pneumoniae-positive stroke patients, as compared with 8% (6 of 84), and 28% (24 of 84), respectively, in the C. pneumoniae-positive healthy controls. (OR = 2.559; 95% CI = 1.105-6.517, P = 0.04 and OR = 2.567; 95% CI = 1.451-4.540 P < 0.001, respectively). The stroke patients with the large vessel pathology exhibited the highest frequency of the mutant allele A (51%). In contrast, amongst the C. pneumoniae-negative subjects, no difference in genotype frequency was observed between the stroke patients and the controls. CONCLUSION: Polymorphism in NOD1 G796A alone did not prove to be a risk factor for stroke in general, but in association with C. pneumoniae infection it appeared to be accompanied by an increased risk of the development of stroke.

Optical platelet aggregometry does not appear useful as a means of assessing the risk of recurrent vascular events in aspirin-treated patients.

OBJECTIVES: To investigate whether the results of optical platelet aggregometry indicate the risk of recurrent ischemic events. MATERIALS AND METHODS: Cerebro- and cardiovascular patients taking aspirin for at least 30 days were studied retrospectively. Ischemic vascular events occurring prior to testing and the presence of vascular risk factors were recorded. RESULTS: 241 subjects were included. Among the 78 patients (32.4%) who displayed recurrent vascular episodes, the age (62.5 +/- 10.6 vs. 58.4 +/- 11.6, P = 0.009) and the proportion of hypertensives (80.8% vs. 68.1%, P = 0.040) were significantly higher when compared with the participants who exhibited single events. The degree of platelet aggregation did not differ significantly between the patients with and those without recurrent episodes. Logistic regression analysis identified only age (OR 1.033, 95% CI 1.008-1.058, P = 0.010), and not aggregation values, as a risk condition for recurrent vascular episodes. CONCLUSIONS: Results of optical platelet aggregometry were not indicative of the risk of recurrent vascular events. The role of conventional risk factors appeared to be more important.