Letter by Lin et al Regarding Article, “Triple Versus Dual Antiplatelet Therapy in Patients With Acute ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention”
To the Editor:
We read with interest the work by Chen et al,1 which reported that triple antiplatelet therapy seems to be superior to dual antiplatelet therapy in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention with drug-eluting stents. Chen et al1 reported the mortality benefits of triple antiplatelet therapy obtained mainly within 30 days after STEMI, reflecting the importance of the addition of cilostazol to aspirin and clopidogrel before stenting. Meanwhile, the authors pointed out the limitation of the nonrandomized trial, that several baseline differences were present between the groups. In our opinion, the advantage of the short-term outcome of triple therapy should be emphasized in higher-risk patients with STEMI undergoing primary percutaneous coronary intervention regardless of whether cilostazol or abciximab was selected.
Because glycoprotein IIb/IIIa inhibitors (abciximab) as adjunctive pharmacological therapy for primary percutaneous coronary intervention in STEMI demonstrated a moderate reduction in mortality at 30 days (2.4% versus 3.4%, P=0.047), we found a similar beneficial result in short-term mortality of cilostazol-based triple therapy in this article (in-hospital death: 2.2% versus 3.4%, P=0.022).2 In addition, the mortality benefit was also shown proportional to the baseline risks in abciximab-combined triple therapy in accordance with the finding that cilostazol adjuvant therapy for STEMI favored patients with old age, diabetes mellitus, and female gender.3
As mentioned in the article, patients in the triple group were more likely to receive angiotensin-converting enzyme inhibitors but less likely to receive calcium channel blockers than those in the dual group during hospitalization. The pharmacological interaction seems to be the main confounder that will affect the final result. As we know, coadministration of calcium channel blockers is associated with decreased platelet inhibition by clopidogrel.4 Angiotensin-converting enzyme inhibitors may also attenuate the effects of aspirin among patients with acute coronary syndromes.5 Therefore, the impacts of different pharmacological interactions of angiotensin-converting enzyme inhibitors or calcium channel blockers to antiplatelet agents in each group on the short-term mortality are difficult to weigh.
Finally, readers may be interested in whether there is an additional benefit of triple antiplatelet therapy compared with dual antiplatelet therapy in reducing the event rate of acute in-stent thrombosis and late acute in-stent thrombosis in correlation to cardiac death, given the focus on drug-eluting stent use for STEMI in this article.
Chen KY, Rha SW, Li YJ, Poddar KL, Jin Z, Minami Y, Wang L, Kim EJ, Park CG, Seo HS, Oh DJ, Jeong MH, Ahn YK, Hong TJ, Kim YJ, Hur SH, Seong IW, Chae JK, Cho MC, Bae JH, Choi DH, Jang YS, Chae IH, Kim CJ, Yoon JH, Chung WS, Seung KB, Park SJ, Korea Acute Myocardial Infarction Registry Investigators. Triple versus dual antiplatelet therapy in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. Circulation. 2009; 119: 3207–3214.
De Luca G, Suryapranata H, Stone GW, Antoniucci D, Tcheng JE, Neumann FJ, Bonizzoni E, Topol EJ, Chiariello M. Relationship between patient’s risk profile and benefits in mortality from adjunctive abciximab to mechanical revascularization for ST-segment elevation myocardial infarction: a meta-regression analysis of randomized trials. J Am Coll Cardiol. 2006; 47: 685–686.