Letter by Doraiswamy Regarding Article, “Intensifying Platelet Inhibition With Tirofiban in Poor Responders to Aspirin, Clopidogrel, or Both Agents Undergoing Elective Coronary Intervention: Results From the Double-Blind, Prospective, Randomized Tailoring Treatment With Tirofiban in Patients Showing Resistance to Aspirin and/or Resistance to Clopidogrel Study”
To the Editor:
Valgimigli et al1 conducted an interesting prospective study on the effect of tirofiban in poor responders to aspirin, clopidogrel, or both undergoing elective coronary intervention. Although the reasons for recruiting low-risk patients in the study are explained,2 this study cannot be incorporated into commonly encountered advanced cardiac patients. Certain additional details and controversies need to be addressed. I find that the placebo group has patients with more risk factors, including hypertension, diabetes mellitus, and hypercholesterolemia, placing them at higher risk for future myocardial infarction than patients who received tirofiban. In common practice, a femoral approach is preferred over a radial approach unless there is extensive femoral/iliac vascular disease and a high risk of bleeding. That could explain why patients had less hemorrhagic complications in the tirofiban group. Also, lower doses of heparin were used in the tirofiban group than the placebo group, contributing to less hemorrhagic complications. Quantification of major and minor bleeds in the study needs to be explained because these are relative terms.
In addition, tirofiban was given between 14 and 24 hours in the study. Is there any difference in the outcome based on the duration of the infusion of the tirofiban in the study? Regarding pulmonary embolism as a complication, how fast were these patients mobilized after the procedure? How long was heparin infused, if any, in these patients after the procedure? Stent thrombosis in the control patient could be related to the duration of heparin use. If the recruited patients were poor responders to aspirin and/or clopidogrel, then what medications/doses of aspirin or clopidogrel were used at discharge in these patients, as major adverse cardiovascular events at 30 days after myocardial infarction were considered as secondary end point?
Also, we could have compared additional groups of control patients who did and did not receive tirofiban and were good responders to aspirin and clopidogrel to determine any difference in the overall outcome. This interesting article inspires future studies to compare abciximab, eptifibatide, and tirofiban in this group of patients.
Valgimigli M, Campo G, de Cesare N, Meliga E, Vranckx P, Furgieri A, Angiolillo DJ, Sabatè M, Hamon M, Repetto A, Colangelo S, Brugaletta S, Parrinello G, Percoco G, Ferrari R; Tailoring Treatment With Tirofiban in Patients Showing Resistance to Aspirin and/or Resistance to Clopidogrel (3T/2R) Investigators. Intensifying platelet inhibition with tirofiban in poor responders to aspirin, clopidogrel, or both agents undergoing elective coronary intervention: results from the double-blind, prospective, randomized Tailoring Treatment With Tirofiban in Patients Showing Resistance to Aspirin and/or Resistance to Clopidogrel study. Circulation. 2009; 119: 3215–3222.
Valgimigli M, Campo G, de Cesare N, Vranckx P, Hamon M, Angiolillo DJ, Sabate M, Ferrari F, Furgieri A, Tumscitz C, Repetto A, Colangelo S, Meliga E, Kubbajeh M, Parrinello G, Percoco G, Ferrari R. Tailoring Treatment With Tirofiban in Patients Showing Resistance to Aspirin and/or Resistance to Clopidogrel (3T/2R) study: rationale for the study and protocol design. Cardiovasc Drugs Ther. 2008; 22: 313–320.