Outcome of Stroke Prevention : Analyses Based on Data from Riks-Stroke and Other Swedish National Registers

The aim of this thesis was to explore variations in stroke prevention and the effect of prevention on outcome. The studies were based on patients registered in the Swedish Stroke Register between 2001 and 2009 and although used to different extents in each paper, additional information was retrieved through linkage to The National Patient Register, the Cause of Death Register, the Prescribed Drug Register and the Total Population Register. Cardiovascular risk factors were prevalent among ischemic stroke (IS) patients; however, they were not always prescribed the drugs recommended, and increasing age was an important negative predictor (Paper I). After IS, the rate of hemorrhage in patients prescribed antiplatelet agents (2.4 per 100 person-years) was double to results from randomized controlled trails, but was similar for patients prescribed warfarin (2.5 per 100 person-years).  Age ≥75 years and previous hemorrhage were associated with a moderately increased risk of future hemorrhage (Paper II). Among IS patients with atrial fibrillation, one-third was prescribed warfarin and two-thirds were prescribed antiplatelets. After adjustment for a propensity score (used to adjust for the non-randomized design), warfarin was associated with a reduced risk of death (0.67; 95% CI, 0.63-0.71) (Paper III). The rate of subsequent hemorrhagic stroke was 0.4 per 100 person-years and the risk did not change (HR 1.04; 95% CI, 0.73-1.48) when later years of the 2000s (inclusion period 2005-8: follow-up until 2009) was compared with earlier years (inclusion period 2001-4: follow-up until 2005) (Paper IV, cohort). Although the risk of first-ever hemorrhagic stroke more than doubled with warfarin than without, the risk did not change between 2006 and 2009 (Paper IV, case-control). In summary, the prescription of secondary preventive drugs varies with age, even though cardiovascular risk factors are prevalent in all ages. The risk of death and hemorrhage are affected by the type of antithrombotic prescribed. Therefore, it is important individual’s stroke and bleeding risks in stroke prevention are assessed

Outcome of Stroke Prevention : Analyses Based on Data from Riks-Stroke and Other Swedish National Registers

The aim of this thesis was to explore variations in stroke prevention and the effect of prevention on outcome. The studies were based on patients registered in the Swedish Stroke Register between 2001 and 2009 and although used to different extents in each paper, additional information was retrieved through linkage to The National Patient Register, the Cause of Death Register, the Prescribed Drug Register and the Total Population Register. Cardiovascular risk factors were prevalent among ischemic stroke (IS) patients; however, they were not always prescribed the drugs recommended, and increasing age was an important negative predictor (Paper I). After IS, the rate of hemorrhage in patients prescribed antiplatelet agents (2.4 per 100 person-years) was double to results from randomized controlled trails, but was similar for patients prescribed warfarin (2.5 per 100 person-years).  Age ≥75 years and previous hemorrhage were associated with a moderately increased risk of future hemorrhage (Paper II). Among IS patients with atrial fibrillation, one-third was prescribed warfarin and two-thirds were prescribed antiplatelets. After adjustment for a propensity score (used to adjust for the non-randomized design), warfarin was associated with a reduced risk of death (0.67; 95% CI, 0.63-0.71) (Paper III). The rate of subsequent hemorrhagic stroke was 0.4 per 100 person-years and the risk did not change (HR 1.04; 95% CI, 0.73-1.48) when later years of the 2000s (inclusion period 2005-8: follow-up until 2009) was compared with earlier years (inclusion period 2001-4: follow-up until 2005) (Paper IV, cohort). Although the risk of first-ever hemorrhagic stroke more than doubled with warfarin than without, the risk did not change between 2006 and 2009 (Paper IV, case-control). In summary, the prescription of secondary preventive drugs varies with age, even though cardiovascular risk factors are prevalent in all ages. The risk of death and hemorrhage are affected by the type of antithrombotic prescribed. Therefore, it is important individual’s stroke and bleeding risks in stroke prevention are assessed

Outcome of Stroke Prevention : Analyses Based on Data from Riks-Stroke and Other Swedish National Registers

The aim of this thesis was to explore variations in stroke prevention and the effect of prevention on outcome. The studies were based on patients registered in the Swedish Stroke Register between 2001 and 2009 and although used to different extents in each paper, additional information was retrieved through linkage to The National Patient Register, the Cause of Death Register, the Prescribed Drug Register and the Total Population Register. Cardiovascular risk factors were prevalent among ischemic stroke (IS) patients; however, they were not always prescribed the drugs recommended, and increasing age was an important negative predictor (Paper I). After IS, the rate of hemorrhage in patients prescribed antiplatelet agents (2.4 per 100 person-years) was double to results from randomized controlled trails, but was similar for patients prescribed warfarin (2.5 per 100 person-years).  Age ≥75 years and previous hemorrhage were associated with a moderately increased risk of future hemorrhage (Paper II). Among IS patients with atrial fibrillation, one-third was prescribed warfarin and two-thirds were prescribed antiplatelets. After adjustment for a propensity score (used to adjust for the non-randomized design), warfarin was associated with a reduced risk of death (0.67; 95% CI, 0.63-0.71) (Paper III). The rate of subsequent hemorrhagic stroke was 0.4 per 100 person-years and the risk did not change (HR 1.04; 95% CI, 0.73-1.48) when later years of the 2000s (inclusion period 2005-8: follow-up until 2009) was compared with earlier years (inclusion period 2001-4: follow-up until 2005) (Paper IV, cohort). Although the risk of first-ever hemorrhagic stroke more than doubled with warfarin than without, the risk did not change between 2006 and 2009 (Paper IV, case-control). In summary, the prescription of secondary preventive drugs varies with age, even though cardiovascular risk factors are prevalent in all ages. The risk of death and hemorrhage are affected by the type of antithrombotic prescribed. Therefore, it is important individual’s stroke and bleeding risks in stroke prevention are assessed

Cause of death in patients with poststroke epilepsy : Results from a nationwide cohort study

The risk of death is increased for persons with epilepsy. The literature on causes of death in epilepsy is based mainly on cohorts with epilepsy of mixed aetiologies. For clinical purposes and improved understanding of mortality in different epilepsies, more information is needed on mortality in epilepsies of specific causes. In poststroke epilepsy (PSE), seizures occur in a setting of vascular disease and high mortality rates. The extent to which epilepsy contributes to mortality in this patient group is poorly understood. We therefore aimed to describe causes of death (COD) in PSE on a national scale. A previously identified cohort of 7740 patients with epilepsy or seizures after a stroke in 2005-2010 was investigated. A total of 4167 deaths occurred before the end of 2014. The standardized mortality ratio for the study cohort was 3.56 (95% CI: 3.45-3.67). The main underlying causes of death were disorders of the circulatory system (60%) followed by neoplasms (12%). Diseases of the nervous system were the sixth leading underlying COD (3%), and epilepsy or status epilepticus was considered the underlying COD in approximately a similar proportion of cases as neurodegenerative disorders (0.9% and 1.1%, respectively). Epilepsy was considered a contributing COD in 14% of cases. Our findings highlight the importance of optimal management of vascular morbidity in patients with PSE. The large proportion of patients with epilepsy as a contributing COD indicate the need of high ambitions also regarding the management of seizures in patients with PSE

Antikoagulantia efter akut ischemisk stroke med förmaksflimmer - Frågan om rätt tidpunkt för insättning kräver randomiserad klinisk prövning.

Early or delayed onset of oral anticoagulant therapy in patients with acute ischemic stroke with atrial fibrillation is an unsolved issue. Retrospectively, 294 patient records at two hospitals were scrutinized according to a protocol consisting of 20 items regarding choice of therapy (warfarin or NOAC), time for onset of therapy, CT findings of bleeding, capacity to swallow, and occurrence of clinical deterioration during the acute phase. Out of 249 patients who survived the acute phase, 116 (47%) patients were given a new prescription of warfarin or NOAC at discharge, while 43 (17 %) continued with anticoagulant therapy already prescribed before the onset of stroke. The median value for new prescriptions in relation to stroke admission was 5 days. The pattern was similar for warfarin and NOAC. Patients in whom anticoagulant therapy was started early were characterized by good capacity to swallow and no signs of bleeding on initial CT. The question »early or delayed onset of oral anticoagulant therapy after acute ischemic stroke with atrial fibrillation« needs to be tested in a randomized clinical trial

Early Versus Delayed Non-Vitamin K Antagonist Oral Anticoagulant Therapy After Acute Ischemic Stroke in Atrial Fibrillation (TIMING) : A Registry-Based Randomized Controlled Noninferiority Study

Background: There are no evidence-based recommendations on the optimal time point to initiate non–vitamin K antagonist oral anticoagulants (NOACs) after acute ischemic stroke in patients with atrial fibrillation. We aimed to investigate the efficacy and safety of early versus delayed initiation of NOAC in these patients. Methods: TIMING (Timing of Oral Anticoagulant Therapy in Acute Ischemic Stroke With Atrial Fibrillation) was a registry-based, randomized, noninferiority, open-label, blinded end-point study at 34 stroke units using the Swedish Stroke Register for enrollment and follow-up. Within 72 hours from stroke onset, patients were randomized to early (≤4 days) or delayed (5–10 days) NOAC initiation, with choice of NOAC at the investigators’ discretion. The primary outcome was the composite of recurrent ischemic stroke, symptomatic intracerebral hemorrhage, or all-cause mortality at 90 days. The prespecified noninferiority margin was 3%. Secondary outcomes included the individual components of the primary outcome. Results: Between April 2, 2017, and December 30, 2020, 888 patients were randomized to either early (n=450) or delayed (n=438) initiation of NOAC. No patient was lost to 90-day follow-up. Mean age was 78.3 years (SD, 9.9 years); 46.2% were women; 49.1% had previously known atrial fibrillation; and 17.5% prior stroke. The primary outcome occurred in 31 patients (6.89%) assigned to early initiation and in 38 patients (8.68%) assigned to delayed NOAC initiation (absolute risk difference, −1.79% [95% CI, −5.31% to 1.74%]; Pnoninferiority=0.004). Ischemic stroke rates were 3.11% and 4.57% (risk difference, −1.46% [95% CI, −3.98% to 1.07%]) and all-cause mortality rates were 4.67% and 5.71% (risk difference, −1.04% [95% CI, −3.96% to 1.88%]) in the early and delayed groups, respectively. No patient in either group experienced symptomatic intracerebral hemorrhage. Conclusions: Early initiation was noninferior to delayed start of NOAC after acute ischemic stroke in patients with atrial fibrillation. Numerically lower rates of ischemic stroke and death and the absence of symptomatic intracerebral hemorrhages implied that the early start of NOAC was safe and should be considered for acute secondary stroke prevention in patients eligible for NOAC treatment

Timing of oral anticoagulant therapy in acute ischemic stroke with atrial fibrillation : Study protocol for a registry-based randomised controlled trial

Background: Oral anticoagulation therapy is recommended for the prevention of recurrent ischemic stroke in patients with atrial fibrillation (AF). Current guidelines do not provide evidence-based recommendations on optimal time-point to start anticoagulation therapy after an acute ischemic stroke. Non-vitamin K antagonist oral anticoagulants (NOACs) may offer advantages compared to warfarin because of faster and more predictable onset of action and potentially a lower risk of intracerebral haemorrhage also in the acute phase after an ischemic stroke. The TIMING study aims to establish the efficacy and safety of early vs delayed initiation of NOACs in patients with acute ischemic stroke and AF. Methods/Design: The TIMING study is a national, investigator-led, registry-based, multicentre, open-label, randomised controlled study. The Swedish Stroke Register is used for enrolment, randomisation and follow-up of 3000 patients, who are randomised (1:1) within 72 h from ischemic stroke onset to either early (≤ 4 days) or delayed (≥ 5-10 days) start of NOAC therapy. The primary outcome is the composite of recurrent ischemic stroke, symptomatic intracerebral haemorrhage, or all-cause mortality within 90 days after randomisation. Secondary outcomes include: individual components of the primary outcome at 90 and 365 days; major haemorrhagic events; functional outcome by the modified Rankin Scale at 90 days; and health economics. In an optional biomarker sub-study, blood samples will be collected after randomisation from approximately half of the patients for central analysis of cardiovascular biomarkers after study completion. The study is funded by the Swedish Medical Research Council. Enrolment of patients started in April 2017. Conclusion: The TIMING study addresses the ongoing clinical dilemma of when to start NOAC after an acute ischemic stroke in patients with AF. By the inclusion of a randomisation module within the Swedish Stroke Register, the advantages of a prospective randomised study design are combined with the strengths of a national clinical quality register in allowing simplified enrolment and follow-up of study patients. In addition, the register adds the possibility of directly assessing the external validity of the study findings. Trial registration: ClinicalTrials.gov, NCT02961348. Registered on 8 November 2016