MUNICH, Germany, Aug. 31 Patients who werediabetic and diagnosed with acute coronary syndromes (ACS) were 40 percentless likely to suffer a heart attack if they were treated with prasugrel vs.clopidogrel, according to a sub-group analysis of the TRITON-TIMI 38 trial(8.2 percent vs. 13.2 percent, P<0.001). In addition, according to this sameanalysis, the combined rate of cardiovascular death, non-fatal heart attackand non-fatal stroke was reduced by 30 percent in diabetes patients treatedwith prasugrel compared to those treated with clopidogrel (12.2 percent vs.17.0 percent, P<0.001). In patients without diabetes, there was alsoimprovement in outcomes with prasugrel, with the primary endpoint occurring in9.2 percent of patients treated with prasugrel and 10.6 percent of patientstreated with clopidogrel (P=0.02).
The diabetic sub-group analysis was presented today by Stephen Wiviott,M.D., Assistant Professor of Medicine at Harvard Medical School andinvestigator with the Thrombolysis in Myocardial Infarction (TIMI) StudyGroup, Brigham & Women's Hospital, Boston, USA, at the Congress of theEuropean Society of Cardiology (ESC) in Munich, Germany. In addition, themanuscript was simultaneously published online in Circulation, the medicaljournal of the American Heart Association (AHA).
"The results observed from this sub-group analysis showed thatantiplatelet therapy with prasugrel resulted in significantly greaterreduction of cardiovascular events among patients with diabetes when comparedto those who were treated with clopidogrel," said Wiviott.
The reduction of cardiovascular events was consistent across the sub-groupof diabetes patients regardless of diabetic therapies (insulin versus noinsulin). The study showed a significant relative risk reduction in theprimary endpoint of cardiovascular death, non-fatal heart attack and non-fatalstroke with prasugrel, 37 percent for insulin treated and 26 percent(P=0.001) for non-insulin treated diabetics. There was also a significantlylower rate of stent thrombosis among diabetes patients treated with prasugrel,resulting in a 48 percent relative risk reduction in stent thrombosis comparedwith clopidogrel (3.6 percent vs. 2.0 percent, P=0.007).
"These findings are interesting in view of previous studies that showedhigher levels of platelet aggregation in insulin-treated diabetes patientsafter dual antiplatelet therapy compared to diabetes patients not treated withinsulin," said Dr. Wiviott.
The main TRITON-TIMI 38 clinical trial, previously published in the NewEngland Journal of Medicine in November 2007 (Vol. 357, No. 20), comparedprasugrel with clopidogrel in patients with ACS undergoing percutaneouscoronary intervention (PCI). In the primary analysis of the trial, prasugrelreduced the risk of the composite endpoint of cardiovascular death, heartattack or stroke by 19 percent, with an increased risk of major bleedingcompared with clopidogrel (2.4 percent vs. 1.8 percent).(1)
In this sub analysis, the rates of major bleeding events were similar forprasugrel (2.5 percent) and clopidogrel (2.6 percent) among patients withdiabetes, regardless of diabetes therapies (insulin versus no insulin).
About Diabetes in Patients with ACS
Among patients with ACS, those with diabetes are at a higher risk forsubsequent cardiovascular events, including death.(2) Several mechanisms mayincrease the risk of events in patients with diabetes, including greaterfrequency of other cardiac risk factors, a greater burden of narrowing of thearteries (atherosclerotic disease), high blood sugar (hyperglycemia),inflammation, and a greater tendency toward blood clots (thrombosis).(3,4,5)
Daiichi Sankyo Company, Limited (TSE: 4568) and Eli Lilly and Company(NYSE: LLY) are co-developing prasugrel, an investigational oral antiplateletagent invented by Daiichi Sankyo