Platelet glycoprotein IIb/IIIa inhibitors reduce the clumping together of platelets in the blood, which can lead to complications during procedures to open narrowed arteries. Tirofiban and abciximab are two such drugs, but each blocks platelet clumping in a slightly different way. Researchers around the world are trying to work out the relevance of these differences with respect to patients' health. Last year, the TARGET investigators showed that abciximab was significantly better than tirofiban at preventing death, heart attacks, and repeated surgery among 4809 patients within 30 days after they had undergone a coronary-artery angioplasty with stent placement.
These investigators, led by Dr David Moliterno from the Cleveland Clinic Foundation, Ohio, USA, now report follow-up data from the TARGET study, which they obtained 6 months after angioplasty. Surprisingly, they found that 148% of the patients taking tirofiban had died, had a heart attack, or had repeat surgery, compared with 143% of those who took abciximab. In other words, the drugs were about equally effective in terms of preventing these longer-term events.
David Moliterno comments: "As studied, abciximab was more protective against a heart attack occurring during, or immediately following, angioplasty. Yet the two drugs were associated with similarly low rates of death and renarrowing of the heart's arteries at 6 months. Our conclusion is that while the more expensive drug (abciximab) is better 'up front', it provides little long-term advantage compared with tirofiban."