Iscover was more effective than acetylsalicylic acid at preventing new ischaemic events. In a study in around 19,000 patients who had recently had a heart attack or an ischaemic stroke, or who had established peripheral artery disease, 939 patients who were given Iscover experienced a new ischemic event (heart attack, ischaemic stroke or death) over a period of one to three years, compared with 1,020 patients who were given acetylsalicylic acid. This corresponds to a relative reduction in risk of 9% compared with acetylsalicylic acid and means that fewer patients will have new ischaemic events if they receive Iscover than if they receive acetylsalicylic acid.

In three studies involving over 61,000 patients with non‑ST segment elevation acute coronary syndrome, 2,172 of whom had a stent inserted during the study, Iscover was given in combination with acetylsalicylic acid and compared with placebo (a dummy treatment). In these studies, which differed in duration from up to 8 days to up to one year, the overall relative risk of an event such as a blocked artery, another heart attack or death, was reduced by 20% when patients were given Iscover and acetylsalicylic acid compared with placebo. There was also a reduction in the patients who had a stent inserted. In 2 studies in 49,000 patients with ST segment elevation myocardial infarction, fewer patients on Iscover had events than patients on placebo (262 against 377 in the CLARITY study, and 2,121 against 2,310 in the COMMIT study).

In a study in around 7,500 patients with atrial fibrillation who had at least one risk factor for vascular events and who could not take vitamin K antagonist therapy, patients were given Iscover together with acetylsalicylic acid or placebo for an average of three years. In this study, Iscover plus acetylsalicylic acid reduced the risk of new events by 11% compared with placebo taken with acetylsalicylic acid, with the largest reduction (28%) seen for stroke.

Study results published in medical journals showed that Iscover was effective for up to 12 months at reducing the occurrence of heart attack, stroke or death in patients treated for heart attack with ST-segment elevation who are having a percutaneous coronary intervention.