Incidence of stroke and mortality due to stroke after acute coronary syndrome

Stroke is a known complication after myocardial infarction (MI) and it is associated with increased mortality. We aimed to establish the true cumulative incidence of stroke and its subtypes and the associated mortality in a contemporary setting among patients treated for acute coronary syndrome (ACS).

A retrospective registry study based on the data of 8,049 consecutive patients treated for ACS in a sole provider of specialized cardiac and neurologic care for a catchment area of over 0.5 million residents between 2007 and 2018. Incident strokes and their subtypes were identified by in-depth review of written hospital records, hospital discharge registry data and causes of death registry data maintained by Statistics Finland up until December 31^st 2020.

During a median follow-up of 5.8 years (IQR 3.2-9.0) 570 ACS patients suffered a stroke. The cumulative incidences of stroke for first week, first month, first year and at thirteen years were: 0.8 %, 1.1 %, 2.2 % and 10.3 %. In long-term, patients with different ACS subtypes had similar cumulative incidence of strokes, although the incidence of in-hospital strokes was highest among myocardial infarction patients. Stroke mortality rate was 32.5 % (n=185/570). The majority (88.8 %) of strokes were ischemic with the proportion being most substantial for in-hospital strokes (95.6 %).

The risk of stroke among patients treated for ACS and the related mortality are still notable in a contemporary setting. A distinctive majority of strokes following ACS were ischemic especially early on after ACS.