Multicenter prospective observational case-control study aimed at characterizing the possible determinants of treatment failure in patients with cerebrovascular disease on secondary prevention with ASA, who are hospitalized in Internal Medicine departments for a recurrent atherothrombotic stroke.

Inclusion Criteria:

1. Age ≥18 years
2. Swallow-test positive
3. Patients hospitalized for a first event of athero-thrombotic stroke (CONTROL group)
4. Patients hospitalized for a recurrence of athero-thrombotic stroke on ASA therapy (CASE group)
5. Informed Consent

Exclusion Criteria:

1. Transient ischemic attack (TIA)
2. Chronic treatment with non-steroidal anti-inflammatory drugs (if occasional, not within 4 days prior to hospitalization)
3. Current treatment with oral or parental anticoagulants at prophylactic or therapeutic doses
4. Current treatment with other antiplatelet agents
5. Thrombolysis and thrombectomy
6. Cardio-embolic stroke CENTRO STUDI FONDAZIONE FADOI Page 10 Studio FADOI.01.2018 Versione n. 2 del 26/09/2019
7. Carotid stenosis >70%, with indication for revascularization
8. Current treatment with ASA (only for patients in the CONTROL group)
9. Acute hepatitis, chronic active hepatitis, liver cirrhosis - or alanine aminotransferase level 3 times or more and/or bilirubin level 2 times or more higher than the upper limit of the normal range
10. Thrombocytopenia (<150000 platelets/μl)
11. Renal failure (eGFR <30 ml/min)
12. Active cancer or disease in complete remission <1 year, except squamous cell carcinoma and basal-cell carcinoma of the skin at initial stage
13. Severe chronic obstructive pulmonary disease (COPD) (oxygen therapy)
14. Uncontrolled hypertension (systolic BP >180 mmHg or diastolic BP >100 mmHg despite antihypertensive treatment)
15. Chronic inflammatory bowel disease
16. Chronic treatment with corticosteroid drugs (for example Prednisone >5 mg/die or equivalent)
17. Pregnancy (in case of child-bearing potential inclusion will be possible in case of negative pregnancy test)

Hospitalized patients with athero-thrombotic stroke, to be divided into CASE group (50 patients experiencing a recurrent stroke while on ASA therapy) and CONTROL group (50 ASA-naïve patients experiencing a first atherothrombotic stroke), with ratio 1:1.