Activated protein C resistance and acute ischaemic stroke: Relation to stroke causation and age

Objectives Resistance to activated protein C (APC) is the most frequent cau se of thrombophilia and a well known risk factor for deep and cerebral vein thrombosis. Its causative role in ischaemic stroke is still a matter of de bate. We undertook this study to determine the prevalence of APC-resistance in a cohort of consecutive patients with acute ischaemic stroke, especiall y with respect to patients' age and the underlying stroke causation. Materi als and methods 489 patients with proven ischaemic stroke were included in this study. Subtypes of stroke were classified according to the TOAST crite ria, i.e. large artery artherosclerosis (LAA), small vessel occlusion (SVO) , cardioembolism (CE), stroke of other etiology (SOE), and stroke of undete rmined etiology (SUE). APC-resistance was determined with a functional meth od with high sensitivity and specificity for the factor V Leiden mutation. The results were compared with the prevalence of APC-resistance in healthy volunteers, all born in the same area. Results APC-resistance was found in 24 of 489 patients (4.9 %) and in 6 of the 112 (5.4 %) control subjects. In the stroke patients, APC-resistance was distributed as follows: LAA 6.5 % (9/138), SVO 3.9 % (4/104), CE 6.7 % (7/104), SOE 3.6 % (1/28), SUE 2.6 % ( 3/115). Prevalence of APC-resistance was not significantly different betwee n young stroke patients (6-45 years) and older patients (7.7 % [5/65] versu s 4.5 % [19/424]). Conclusions Prevalence of APC-resistance is not increase d in patients with ischaemic stroke. Additionally, no significant differenc es in the prevalence of APC-resistance are evident within the various strok e subtypes.