Search
What are you looking for?
Start main content

Press Releases

Press Releases

https://www.med.cuhk.edu.hk/press-releases/cuhk-study-reveals-an-elevated-stroke-risk-with-switching-oral-anticoagulants-in-atrial-fibrillation-patients-who-developed-breakthrough-strokes-during-anticoagulation-therapy
https://www.med.cuhk.edu.hk/press-releases/cuhk-study-reveals-an-elevated-stroke-risk-with-switching-oral-anticoagulants-in-atrial-fibrillation-patients-who-developed-breakthrough-strokes-during-anticoagulation-therapy

CUHK study reveals an elevated stroke risk with switching oral anticoagulants in atrial fibrillation patients who developed breakthrough strokes during anticoagulation therapy

The Division of Neurology at The Chinese University of Hong Kong (CUHK)’s Faculty of Medicine (CU Medicine) conducted the world’s first population-based study to evaluate the impact of different antithrombotic approaches on patient outcomes after the first episode of ischemic stroke despite taking direct oral anticoagulants (DOACs). It revealed an elevated risk of recurrent ischemic stroke in non-valvular atrial fibrillation (NVAF) patients on alternative oral anticoagulants. The findings have recently been published in the top international medical journal Neurology.

 

In light of World Brain Day on July 22, the research team recommends patients be cautious about the practice of switching to warfarin or another DOAC after the first ischemic stroke unless the benefits outweigh the risks.

 

Dr Bonaventure Ip and Prof Thomas Leung

CU Medicine study reveals an elevated risk of recurrent ischemic stroke in atrial fibrillation (AF) patients on alternative oral anticoagulants, warfarin in particular, after the first episode of ischemic stroke. (From left) Assistant Professor Dr Bonaventure Ip Yiu-ming and Lee Quo Wei Professor of Neurology Professor Thomas Leung Wai-hong from the Division of Neurology in the Department of Medicine and Therapeutics at CU Medicine. 

AF could lead to the formation of blood clots and result in stroke

 

Atrial fibrillation (AF) is a kind of arrhythmia. Irregular heartbeats in AF affect blood circulation in the heart, which may lead to the formation of blood clots. Stroke may result from occlusion of brain vessels when the blood clot formed in the heart is carried to the brain via the blood stream, which is termed as cardioembolic stroke. In general, an AF patient is five times more likely to suffer from a stroke than a normal person. Furthermore, AF-related stroke is the most severe form of ischemic stroke, with high mortality and disability rates. In Hong Kong, AF-related stroke constitutes almost 30% of all ischemic stroke cases.

 

NVAF patients switching anticoagulation strategies face a higher risk of recurrent ischemic stroke

 

Previous studies showed that AF-related stroke is highly preventable with oral anticoagulation. Although oral anticoagulation effectively reduces ischemic stroke risk by 60-70% in AF patients, a significant proportion of them may still suffer from ischemic stroke despite DOACs. Given that those who have previously experienced ischemic stroke exhibit a greater likelihood of recurrent events, it is imperative to improve secondary stroke prevention for patients who suffer from ischemic stroke despite taking DOACs.

 

Dr Yip

Dr Ip says the study provides clinical evidence that elucidating the risk factors and precise etiologies of ischemic stroke despite DOACs may be more important than switching or adding antithrombotic agents.

The research team led by Dr Bonaventure Ip Yiu-ming, Assistant Professor in the Department of Medicine and Therapeutics at CU Medicine, conducted the first population-based clinical research to evaluate the clinical trajectory of patients who developed ischemic stroke despite taking DOACs via the Clinical Data Analysis and Reporting System (CDARS), a territory-wide electronic healthcare database from the Hospital Authority. Among the 45,946 public hospital patients with non-valvular AF who received DOACs from 2015 to 2020, 2,337 developed ischemic stroke despite DOAC treatment. Alarmingly, 13.4% of these patients developed another episode of ischemic stroke over a median follow-up period of 16.5 months.

 

The study further compared patient outcomes between those receiving DOACs with or without an alternative antithrombotic regimen and identified the risk factors for recurrent ischemic stroke while on anticoagulation. 

About projected health risks for non-valvular AF patients who have switched DOAC treatment after first stroke

  • A transition from the initial DOAC treatment to warfarin or another DOAC after an ischemic stroke increased the risk of recurrent ischemic stroke by 96% and 62% respectively.
  • The “switched DOAC” group also had more than twice the risk of acute coronary syndrome in comparison to the “DOAC unchanged” group.
  • There was no benefit from adding an antiplatelet agent to prevent recurrent ischemic stroke among non-valvular AF patients.
  • Several risk factors are associated with recurrent ischemic stroke, including advanced age, diabetes mellitus (DM), concurrent use of cytochrome P450/P-glycoprotein (CYP/P-gp) modulators, and large artery atherosclerotic disease (LAD).

Dr Ip emphasised, “Ischemic stroke despite DOACs is a common clinical conundrum faced by emergency, internal medicine and stroke physicians worldwide. Our study provides the important insight that change isn’t always better, especially from the original DOAC to warfarin. More importantly, our work suggested that elucidating the risk factors and precise etiologies of ischemic stroke despite DOACs may be more important than switching or adding antithrombotic agents.”

 

Prof Thomas Leung

Professor Thomas Leung says it is crucial for AF patients to maintain the habit of taking oral anticoagulants timely to minimize the risk of recurrent stroke.

Professor Thomas Leung Wai-hong, Head of the Division of Neurology and Lee Quo Wei Professor of Neurology in CU Medicine’s Department of Medicine and Therapeutics, concluded, “Our study provides evidence-based guidance for antithrombotic management for non-valvular AF patients after ischemic stroke despite DOACs. AF is the most common cause of stroke among the elderly. As a result of the ageing population, we believe that the number of AF-related stroke patients will continue to rise. We also encourage patients with AF to seek regular medical follow-up and adhere to the DOAC regimen, which is of paramount importance to reduce the risk of recurrent ischemic stroke.”

The research team reminds the public that the prevention of AF and stroke must begin in daily life. Once an individual develops risk factors for AF or stroke, including advanced age, hypertension, diabetes and congestive heart failure, medication can lower the chance of stroke but a residual risk exists. To minimise the risk of developing cardiovascular and cerebrovascular diseases, the research team recommends a healthy lifestyle that includes a balanced diet, regular exercise, moderate alcohol consumption, smoking cessation and stress management.

 

Patient sharing

AF patient Ms. Shek was found to have ischemic stroke early this year. Luckily, she was sent to the hospital quickly and received endovascular thrombectomy. She has been taking  oral anticoagulants timely since then and carefully managing other health risk factors such as blood pressure and cholesterol, in order to lower the risk of a secondary stroke.

About World Brain Day

 

The World Federation of Neurology marked World Brain Day on 22 July with a call to increase public awareness and promote brain health advocacy, reducing the healthcare burden from brain disorders. This year’s theme, “Brain Health and Disability”, aims to raise public awareness of the prevention of disability associated with brain diseases. 

More Press Releases

CUHK develops novel retrievable nanorobots for targeted and enhanced thrombolysis potentially saving stroke patients from brain damage

CUHK develops novel retrievable nanorobots for targeted and enhanced thrombolysis potentially saving stroke patients from brain damage

Research
CUHK Sees Atrial Fibrillation-related Stroke Cases 3 Times Higher Over 15 Years

CUHK Sees Atrial Fibrillation-related Stroke Cases 3 Times Higher Over 15 Years

Research
CUHK Advocates Stringent Control of Cardiovascular Risks for Reopening of Narrowed Brain Arteries - A New Paradigm to Prevent Recurrent Stroke (Available in Chinese only)

CUHK Advocates Stringent Control of Cardiovascular Risks for Reopening of Narrowed Brain Arteries - A New Paradigm to Prevent Recurrent Stroke (Available in Chinese only)

Research
CUHK and PolyU Jointly Introduce TeleStroke for 24-hour Thrombolysis Service at Prince of Wales Hospital

CUHK and PolyU Jointly Introduce TeleStroke for 24-hour Thrombolysis Service at Prince of Wales Hospital

Clinical service
CUHK Proves External Counterpulsation Helps Augment Cerebral Blood Flow among Ischemic Stroke Patients

CUHK Proves External Counterpulsation Helps Augment Cerebral Blood Flow among Ischemic Stroke Patients

Research
Good News for Asian Patients First Local Clinical Study Shows High Success Rate and Effectiveness of Stenting for Intracranial Stenosis in Preventing Ischaemic Stroke

Good News for Asian Patients First Local Clinical Study Shows High Success Rate and Effectiveness of Stenting for Intracranial Stenosis in Preventing Ischaemic Stroke

Research
CU Medicine completes world’s first study evaluating intracerebral hemorrhage treatments for Chinese patients with atrial fibrillation

CU Medicine completes world’s first study evaluating intracerebral hemorrhage treatments for Chinese patients with atrial fibrillation

Research
CUHK celebrates World Brain Day 2022  Calls for prevention of cerebral small vessel disease to lower the risks of stroke and cognitive impairment

CUHK celebrates World Brain Day 2022 Calls for prevention of cerebral small vessel disease to lower the risks of stroke and cognitive impairment

Research
CUHK Launches a Population-based Programme to Evaluate and Track Brain Health Status  of 5,000 Hong Kong Residents for Free

CUHK Launches a Population-based Programme to Evaluate and Track Brain Health Status of 5,000 Hong Kong Residents for Free

Research
CUHK Professor Receives World Honour For Stroke Services Pioneering an Innovative 3-in-1 Multi-Target Therapy to Repair Damaged Brain After Stroke and Enhance Functional Recovery

CUHK Professor Receives World Honour For Stroke Services Pioneering an Innovative 3-in-1 Multi-Target Therapy to Repair Damaged Brain After Stroke and Enhance Functional Recovery

Awards and honors
CUHK Jointly Discovers New Therapeutic Solution for Minor Stroke in Global Study with over 30 Countries

CUHK Jointly Discovers New Therapeutic Solution for Minor Stroke in Global Study with over 30 Countries

Research
CUHK Sees Early Evaluation of TIA Patients Reduce Rate of Stroke by 70% in a Global Study of 21 Countries

CUHK Sees Early Evaluation of TIA Patients Reduce Rate of Stroke by 70% in a Global Study of 21 Countries

Research
CUHK Screening Reveals 1 in 3 Older Adults in Community Suffer Brain Small Vessel Disease, Early Prevention Recommended

CUHK Screening Reveals 1 in 3 Older Adults in Community Suffer Brain Small Vessel Disease, Early Prevention Recommended

Clinical service
Radiotherapy to Head and Neck Raises Risk for Stroke CUHK Proved Effectiveness of Carotid Angioplasty and Stenting

Radiotherapy to Head and Neck Raises Risk for Stroke CUHK Proved Effectiveness of Carotid Angioplasty and Stenting

Research
CUHK Research Reveals that Stroke Triggers Alzheimer’s Dementia Risk of Alzheimer’s Dementia Can be Reduced by Enhancing Vascular Health

CUHK Research Reveals that Stroke Triggers Alzheimer’s Dementia Risk of Alzheimer’s Dementia Can be Reduced by Enhancing Vascular Health

Research
CUHK Proves the Potent Efficacy of Stenting for Carotid Artery Narrowing and Cardiac Contractility Modulation for Heart Failure

CUHK Proves the Potent Efficacy of Stenting for Carotid Artery Narrowing and Cardiac Contractility Modulation for Heart Failure

Research
A CUHK-led international team develops the world’s first AI model using fundus photographs alone to detect Alzheimer’s disease

A CUHK-led international team develops the world’s first AI model using fundus photographs alone to detect Alzheimer’s disease

Research
Most Deaths from COVID-19 in Hong Kong are of 60 Years Old or Above CUHK Initiated International Effort in Devising Strategies to Protect Older People with Dementia amid COVID-19 Pandemic

Most Deaths from COVID-19 in Hong Kong are of 60 Years Old or Above CUHK Initiated International Effort in Devising Strategies to Protect Older People with Dementia amid COVID-19 Pandemic

Research
CUHK Establishes Margaret K.L. Cheung Research Centre for Management of Parkinsonism  To Develop Innovative Solutions to Slow Disease Progression

CUHK Establishes Margaret K.L. Cheung Research Centre for Management of Parkinsonism To Develop Innovative Solutions to Slow Disease Progression

Research
CUHK Conducts World’s First Family Study on Rapid Eye Movement Sleep Behaviour Disorder to Investigate Familial Link with Parkinson’s Disease

CUHK Conducts World’s First Family Study on Rapid Eye Movement Sleep Behaviour Disorder to Investigate Familial Link with Parkinson’s Disease

Research
CUHK Pioneers in Developing Standardised Tests for Screening Cognitive Impairment in the Ageing Population in Hong Kong

CUHK Pioneers in Developing Standardised Tests for Screening Cognitive Impairment in the Ageing Population in Hong Kong

Clinical service
CUHK Launches World’s First Study Utilizing Retinal Imaging for Alzheimer’s Disease Screening in Chinese Population

CUHK Launches World’s First Study Utilizing Retinal Imaging for Alzheimer’s Disease Screening in Chinese Population

Research
CUHK’s Gerald Choa Neuroscience Centre Unveils Mystery of How Brain Learns Motor Skills

CUHK’s Gerald Choa Neuroscience Centre Unveils Mystery of How Brain Learns Motor Skills

Research
CUHK Opens Therese Pei Fong Chow Research Centre for Prevention of Dementia and Establishes a One-stop Online Platform to Provide Information on Dementia

CUHK Opens Therese Pei Fong Chow Research Centre for Prevention of Dementia and Establishes a One-stop Online Platform to Provide Information on Dementia

Research
CUHK Sets up the Global First Research Registry on Early Onset Dementia in Chinese Population

CUHK Sets up the Global First Research Registry on Early Onset Dementia in Chinese Population

Research
CUHK Introduces High Frequency Oscillations to Determine Resection Margin Increases the Effectiveness of Complex Epilepsy Surgery by around 30%

CUHK Introduces High Frequency Oscillations to Determine Resection Margin Increases the Effectiveness of Complex Epilepsy Surgery by around 30%

Surgical advancement
Joint Study by CUHK and HKSH Reveals Patients with Comorbid REM Sleep Behavior Disorder and Depression may Suffer from Early-stage Neurodegeneration

Joint Study by CUHK and HKSH Reveals Patients with Comorbid REM Sleep Behavior Disorder and Depression may Suffer from Early-stage Neurodegeneration

Research
CUHK Advocates Atrial Fibrillation Screening and Drug Education to Reduce Risk of Stroke among Elderly

CUHK Advocates Atrial Fibrillation Screening and Drug Education to Reduce Risk of Stroke among Elderly

Clinical service
Hong Kong’s First Scientist Awarded Runner-up for the 2014 Eppendorf and Science Prize for Neurobiology CUHK Medical Student Dedicated to Unraveling Mystery of Neuronal Circuits

Hong Kong’s First Scientist Awarded Runner-up for the 2014 Eppendorf and Science Prize for Neurobiology CUHK Medical Student Dedicated to Unraveling Mystery of Neuronal Circuits

Awards and honors
CUHK New Research Reveals Better Efficacy of New Oral Anticoagulant for Stroke Prevention in Asian Patients with Atrial Fibrillation

CUHK New Research Reveals Better Efficacy of New Oral Anticoagulant for Stroke Prevention in Asian Patients with Atrial Fibrillation

Research
Dr. Lui Che Woo Distinguished Professor Public Lecture by Prof. Steven C. Cramer on Brain Repair after Stroke

Dr. Lui Che Woo Distinguished Professor Public Lecture by Prof. Steven C. Cramer on Brain Repair after Stroke

Education
CUHK Announces Latest Medical Treatment for Minor Stroke

CUHK Announces Latest Medical Treatment for Minor Stroke

Research
CUHK Develops an Automatic Retinal Image Analysis System to Help Diabetes Patients and Elderly Prevent Stroke

CUHK Develops an Automatic Retinal Image Analysis System to Help Diabetes Patients and Elderly Prevent Stroke

Research

Our Expert List

Many experts under the Faculty of Medicine are available for media interview.
Please click here for the expert list or contact us.