The purpose of the study is to describe patient characteristics and drug usage among patients that are prescribed ticagrelor for the first time and to compare them with patients who are prescribed clopidogrel and prasugrel for the first time.

A further purpose is to ascertain and estimate the crude incidence rate of bleeding, arrhythmias, heart failure, acute renal failure, acute liver failure, dyspnoea and gout among new users in the three cohorts of ticagrelor, clopidogrel and prasugrel.

Inclusion Criteria:

• First time users of ticagrelor, clopidogrel and prasugrel, respectively

Exclusion Criteria:

• Individuals with more than one of above three antiplatelet drugs dispensed the same day

All patients aged 20 to 84 years before their first study drug dispension (start date) will be included in the study. The study period will start the first month after ticagrelor market introduction in Sweden (the first of June 2011),