Landmark analyses of LA stability and prospective risk of thrombosis and mortality. The blue dashed line represents the landmark date, which was set at 1.5 years after study inclusion. This landmark date was chosen because more than half of the first negative LA tests had occurred by that time. Solid lines represent thrombosis risks after the landmark date in those patients that had exclusively positive LA tests within the first 1.5 years of follow-up, and dashed lines represent thrombosis risks after the landmark date in those patients that had at least 1 negative LA test within the first 1.5 years of follow-up, respectively. (A) Risk of arterial thrombosis. (B) Risk of venous thromboembolism. (C) Risk of overall thrombosis (arterial plus or minus venous). (D) Risk of mortality.