Risk of stroke in patients with prior VKA or DOAC: A population-based real-world registry analysis

INTRODUCTION

To date, risk assessment of suffering ischemic and hemorrhagic stroke in individuals under oral anticoagulation (OAC) is limited to hospital-based cohorts and patients with atrial fibrillation.

PATIENTS AND METHODS

Through the combination of three individual datasets, (1) the population-based Tyrolean Stroke Pathway database, prospectively documenting all (unselected) stroke patients in the entire federal state of the Tyrol and (2) nation-wide prescription data, detailing each reimbursed prescription in Austria as well as (3) the Austrian Stroke Unit Registry, a nation-wide registry comprising data on all patients admitted to any of the 38 stroke units in Austria, we assessed risk of stroke in patients with prior oral anticoagulation and compared characteristics of patients taking direct oral anticoagulants and Vitamin-K-Antagonists.

RESULTS

In Austria, oral anticoagulant prescription reimbursements increased from 292,475 in 2015 to 389,407 in 2021. In the Tyrol, prior oral anticoagulation treatment was evident in 586 of 3861 (15.2%) patients with ischemic and 131 of 523 (25.0%) with hemorrhagic stroke, with 20% and 35% of those stroke patients respectively having prior oral anticoagulation due to other indications than non-valvular atrial fibrillation. Considering prescription rates, treatment with direct oral anticoagulants was associated with a reduced stroke risk compared to Vitamin-K-Antagonists, especially in ischemic (1.05% vs 0.62%; RR 0.59, p < 0.001) but also in hemorrhagic stroke, even if less pronounced (0.21% vs 0.14%; RR 0.68, p = 0.06). In Austria, prior intake of direct oral anticoagulants was associated with lower risk of suffering acute large vessel occlusion stroke (RR 0.79, p = 0.003).

DISCUSSION AND CONCLUSIONS

One in seven patients suffering ischemic and one in four suffering hemorrhagic stroke had prior oral anticoagulation treatment. Both ischemic and hemorrhagic strokes are less frequent in those with direct oral anticoagulant intake compared to those taking Vitamin-K-Antagonists. Establishment of clear standard operating procedures on how to best care for acute stroke patients with oral anticoagulation is essential.

Stroke Care Pathway ensures high-quality stroke management in the COVID-19 pandemic

The aim of our study was to assess whether a well-established federal state-wide Stroke Care Pathway delivering high quality stroke care can cope with the COVID-19 pandemic and associated measures to contain the virus spread. The retrospective analysis is based on a prospective, quality-controlled, population-based registry of all stroke patients in the Tyrol, a federal state of Austria and one of the early hot-spots of COVID-19 in Europe. Patient characteristics, pre-hospital management, intra-hospital management and post-hospital were analysed. All residents of the Tyrol suffering ischemic stroke in 2020 (n = 1160) and four pre-COVID-19 years (n = 4321) were evaluated. In 2020, the annual number of stroke patients was the highest in this population-based registry. When local hospitals were overwhelmed with SARS-CoV-2-patients, stroke subjects were temporarily allocated to the comprehensive stroke centre. Stroke severity, quality metrics of stroke management, serious complications, and post-stroke mortality did not differ between 2020 and the four comparator years. Notably, iv. thrombolysis-rate was similar (19.9% versus 17.4%, P = 0.25) and endovascular stroke treatment even better (5.9% versus 3.9%, P = 0.003) but resources for in-patient rehabilitation were limited (25.8% versus 29.8%, P = 0.009). Concluding, a well-established Stroke Care Pathway was able to maintain high-quality acute stroke care even when challenged by a global pandemic.

Heterozygosity for the C282Y mutation in the hemochromatosis gene is associated with increased serum iron, transferrin saturation, and hemoglobin in young women: a protective role against iron deficiency?

Genetic hemochromatosis (GH) is the most common autosomal-recessive disorder (1 in 300 in populations of Celtic origin). Homozygosity for a C282Y mutation in the hemochromatosis (HFE) gene is the underlying defect in approximately 80% of patients with GH, and 3. 2-13% of Caucasians are heterozygous for this gene alteration. Because the high frequency of this mutation may result from a selection advantage, the hypothesis was tested that the C282Y mutation confers protection against iron deficiency in young women. To address this question the genotype of codon 282 was determined in a cohort of 468 unrelated female healthcare workers, ages 18-40 years. In all study participants, a complete blood count was obtained, and erythrocyte distribution width, serum iron, transferrin, transferrin saturation, and ferritin were measured. Two individuals were homozygous for the C282Y mutation, 44 were heterozygous, and 416 were homozygous for the wild-type allele. Heterozygous women had significantly higher values for hemoglobin (P = 0.006), serum iron (P = 0.013), and transferrin saturation (P = 0. 006) than women homozygous for the wild-type allele. Our data provide evidence for a protective role of the C282Y mutation in the HFE gene against iron deficiency in young women and suggest that a more efficient utilization of nutritional iron may have contributed to the high prevalence of the mutation in Caucasian populations.

Heterozygosity for the C282Y mutation in the hemochromatosis gene is associated with increased serum iron, transferrin saturation, and hemoglobin in young women: a protective role against iron deficiency?

Genetic hemochromatosis (GH) is the most common autosomal-recessive disorder (1 in 300 in populations of Celtic origin). Homozygosity for a C282Y mutation in the hemochromatosis (HFE) gene is the underlying defect in ∼80% of patients with GH, and 3.2–13% of Caucasians are heterozygous for this gene alteration. Because the high frequency of this mutation may result from a selection advantage, the hypothesis was tested that the C282Y mutation confers protection against iron deficiency in young women. To address this question the genotype of codon 282 was determined in a cohort of 468 unrelated female healthcare workers, ages 18–40 years. In all study participants, a complete blood count was obtained, and erythrocyte distribution width, serum iron, transferrin, transferrin saturation, and ferritin were measured. Two individuals were homozygous for the C282Y mutation, 44 were heterozygous, and 416 were homozygous for the wild-type allele. Heterozygous women had significantly higher values for hemoglobin (P = 0.006), serum iron (P = 0.013), and transferrin saturation (P = 0.006) than women homozygous for the wild-type allele. Our data provide evidence for a protective role of the C282Y mutation in the HFE gene against iron deficiency in young women and suggest that a more efficient utilization of nutritional iron may have contributed to the high prevalence of the mutation in Caucasian populations.

Urinary apo(a) discriminates coronary artery disease patients from controls

Increased plasma lipoprotein (a) (Lp(a)) levels are associated with premature cardiovascular diseases and stroke. Since Lp(a) immune reactivity is found in urine we compared urinary apolipoprotein (a) (apo(a)) with plasma Lp(a) levels in 116 patients suffering from angiographically proven coronary artery diseases with that of 109 controls. Urinary apo(a) investigated by immuno blotting, revealed a distinct apo(a) fragmentation pattern with molecular weights between 50 and 160 kDa. Apolipoprotein B however was not secreted into urine. Lp(a) and apo(a) were measured by a fluorescence immuno assay. Within single individuals, urinary apo(a) levels correlated significantly with creatinine (Rho, 0.98; P < 0.0005). Medians and 25/75 percentiles of urinary apo(a) in coronary artery disease (CAD) patients were 5.70, 3.25 and 10.35 microg/dl and in controls 2.64, 1.43 and 3.50 microg/dl respectively. At cut-off levels of 30 mg/dl for plasma Lp(a) and 10 microg/dl of urinary apo(a) respectively, both paramenters showed comparable sensitivities (33.8% vs. 26.7%), yet the specificity (76.1% vs. 91.7%) and the positive predictive value (60.0% vs.76.4%) of urinary apo(a) were much higher. In receiver-operating characteristic plots, urinary apo(a) was much more sensitive at high specificities i.e. greater than 60% as compared to Lp(a). Urinary secretion of apo(a) fragments normalized to creatinine is stable in a given individual and significantly associated with coronary artery disease.