Non-vitamin K-dependent Oral Anticoagulants Have a Positive Impact on Ischaemic Stroke Severity in Patients With Atrial Fibrillation

Simon Hellwig; Ulrike Grittner; Heinrich Audebert; Matthias Endres; Karl Georg Haeusler

Disclosures

Europace. 2018;20(4):569-574. 

In This Article

Results

Out of 3669 patients suffering from acute ischaemic stroke or TIA, 671 (18.3%) had a medical history of AF before index stroke. Sixteen patients had a CHA2DS2-VASc score < 2 and were not included in further analysis because anticoagulation was not (definitively) indicated before the index stroke. Baseline characteristics of 655 patients with known AF and a CHA2DS2-VASc score ≥ 2 before the index stroke are depicted in Table 1. In total, 530 (80.9%) out of 655 patients (mean age 80 years; 55.4% female) suffered an ischaemic stroke and 125 (19.1%) patients had a TIA. Median NIHSS score was 5 (IQR 1–12) on admission, and 6 (IQR 3–14) after excluding TIA patients. Forty-three (6.6%) of 655 stroke patients with AF died during the in-hospital stay [median 5 days (IQR 4–8)].

Medical Stroke Prevention Before Admission in Patients With Known AF Before Index Stroke

From all 655 patients with known AF and a CHA2DS2-VASc score ≥ 2 before the index stroke, 325 (49.6%) received oral anticoagulation before admission [VKA phenprocoumon n = 166 (25.3%), n = 75 (11.5%) with INR ≥ 2 on admission; NOAC n = 159 (24.3%)]. Forty-seven (14.5%) of 325 anticoagulated patients also took a platelet inhibitor (+VKA n = 19; +NOAC n = 28). Three patients received fondaparinux and two patients therapeutic-dose intravenous heparin. Furthermore, 206 (31.5%) out of 655 patients received a platelet inhibitor (dual therapy n = 20). While 20 (3.1%) patients had low-dose heparin, 99 (15.1%) patients had no antithrombotic medication (Table 1). Comparing patient cohorts receiving a NOAC, VKA, platelet inhibitor or no medical stroke prevention to each other, significant differences were observed regarding age, gender, previous stroke as well as co-existing heart failure, thrombolysis on admission, NIHSS as well as mRS on admission (Table 1). A reduced dose of rivaroxaban as well as apixaban was prescribed in 61% and 49% of the respective patient cohort (Supplementary material online, Table S1).

Impact of Oral Anticoagulants on Stroke Severity on Admission

On hospital admission, 190 (29.0%) out of 655 patients with known AF and a CHA2DS2-VASc score ≥ 2 before the index stroke had a NIHSS ≥ 11 indicating severe stroke. In bivariate analysis, old age, female sex, co-existing heart failure, coronary artery disease, and malignant tumour were associated with a higher probability of severe stroke on admission (Supplementary material online, Table S2). After adjustment for confounders, VKA intake resulting in an INR ≥ 2 on admission [OR 0.23 (95% CI 0.10–0.53)] as well as NOAC intake [OR 0.48 (95% CI 0.27–0.86)] were inversely associated with severe stroke on admission when compared with patients without antithrombotic medication at stroke onset (Table 2).

Impact of Oral Anticoagulants on Functional Outcome at Hospital Discharge

Comparing patient cohorts receiving different therapeutic regimens before admission, significant differences were observed regarding the rate of intravenous thrombolysis and NIHSS score on admission but not regarding the duration of the in-hospital stay (Table 1). At discharge, 342 (52.2%) out of 655 patients with known AF and a CHA2DS2-VASc score ≥ 2 before the index stroke had a mRS > 2 indicating poor functional outcome. In bivariate analysis, old age, co-existing diabetes, heart failure, and higher NIHSS score on admission were associated with poor functional outcome (Supplementary material online, Table S2). In multivariable analysis, VKA intake resulting in an INR ≥ 2 on admission [OR 0.33 (95% CI 0.17–0.64)] as well as NOAC intake [OR 0.49 (95% CI 0.28–0.86)] were inversely associated with poor functional outcome at hospital discharge when compared with patients without antithrombotic medication at stroke onset (Table 2).

Adherence Regarding NOAC Intake Before Admission

According to documented patient statements, NOAC intake was not discontinued immediately before admission in 159 AF patients. Patient-reported daily dose and the results of routine coagulation tests (INR, aPTT, or thrombin time) on admission are depicted in Supplementary material online, Table S2. Overall, 90 (56.6%) NOAC patients had altered routine coagulation tests indicating an anticoagulatory effect at stroke onset. Compared with patients without antithrombotic medication, NOAC patients with altered coagulation tests had a significantly lower rate of severe stroke (NIHSS ≥ 11) on admission (18.9% vs. 40.4%; OR 0.41 (95% CI 0.20–0.83) adjusted for age, sex, coronary artery disease, malignant tumour, peripheral artery disease, heart failure), while NOAC patients without altered coagulation tests had a non-significant lower rate of severe stroke (26.1%; adjusted OR 0.62 (95% CI 0.31–1.25).

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....