High blood pressure is a key risk factor for strokes and heart attacks. As many as 10% of the population have a condition where the heart beats irregularly, called atrial fibrillation, which is also a risk factor for stroke. Those with atrial fibrillation typically receive medication that thins the blood to prevent blockage type strokes. However, there are several types of strokes and blood pressure still remains an important risk factor for certain types of stroke (and other cardiovascular (heart, brain or blood vessels) and non-cardiovascular problems). In particular, if blood pressure is high, one may be at higher risk of having a bleeding type stroke on the brain. Though blood thinners minimise blockage type strokes, they increase the risk of bleeding type strokes. Currently, there are no established blood pressure thresholds for patients on blood thinning medication. This study will help inform current practice and provide the potential to set thresholds to ensure safer initiation and maintenance processes for doctors using blood thinners.
The primary objective of this research is to understand the blood pressure (BP) thresholds at which recurrent stroke, myocardial infarction, all cause-mortality as well as symptomatic intracranial haemorrhage and significant gastrointestinal bleeding occur post non-VKA oral anticoagulant (NOACs) initiation for atrial fibrillation (AF). Using HES- and ONS-linked data, pre-initiation BP, post-initiation BP and trend values (including BP variability) parameters will be examined for relationships with adverse cardiovascular outcomes in an effort to determine a 'threshold' mean systolic BP for initiation and maintenance on NOACs.
Health Outcomes to be Measured:
Outcomes include first stroke, recurrent stroke, myocardial infarction, symptomatic intracranial bleed, significant gastrointestinal bleed, CVD-related mortality and all-cause mortality.