Researchers analyzed data from a previous clinical trial involving over 2,100 patients who had both atrial fibrillation (an irregular heartbeat) and stable coronary artery disease (narrowed heart arteries). They split patients into two groups based on their baseline systolic blood pressure (the top number in a blood pressure reading): a 'high' group (over 126 mmHg) and a 'low' group (126 mmHg or less). The main goal was to see if blood pressure levels and different blood-thinning treatments affected patient outcomes.
They found that patients in the low blood pressure group had a 38% higher risk of experiencing a cardiovascular event (like a heart attack or stroke) or dying from any cause, compared to the high blood pressure group. Within the low blood pressure group, patients who took just the blood thinner rivaroxaban had a lower risk of these events and a lower risk of major bleeding compared to those who took rivaroxaban plus an antiplatelet drug (like aspirin).
It is very important to understand that this was a 'post-hoc' analysis. This means researchers looked back at data that was already collected for a different purpose. The findings show an association or link, but they do not prove that lower blood pressure caused the worse outcomes. The results are specific to the patients in this particular trial and may not apply to everyone.
Readers should take from this that managing blood pressure and blood-thinning therapy in patients with these two heart conditions is complex. This analysis provides an interesting observation for doctors to consider, but it is not strong enough evidence to change current medical practice. Patients should not make any changes to their medications or blood pressure goals based on this study alone and should always talk with their own doctor.