title: Impact of tirofiban on angiographic morphologic features of high-burden thrombus formation during direct percutaneous coronary intervention and short-term outcomes.
abstract: BACKGROUND
  Recently, we demonstrated that angiographic morphologic features of high-burden thrombus formation are independent predictors of combined slow flow (ie, Thrombolysis in Myocardial Infarction [TIMI] grade 2) and no reflow (ie, </= TIMI grade 1) in the infarct-related artery (IRA) after direct percutaneous coronary intervention (d-PCI) for the treatment of acute myocardial infarction (AMI). Current data have demonstrated that when administered in conjunction with PCI for acute coronary syndrome, platelet glycoprotein IIb/IIIa inhibitors can provide additional clinical benefits. Thus, we hypothesized that after pretreatment with tirofiban, angiographic morphologic features of high-burden thrombus formation would no longer be independent predictors of combined slow flow and no reflow after treatment with d-PCI.
  
  
  RESULTS
  Between January 2001 and April 2002, tirofiban was administered to 210 consecutive patients with ST-segment elevated AMI before coronary angiography was performed, and 84 patients (40.0%) were found to have high-burden thrombus formation in the IRA. The TIMI flow grade of the IRA was assessed immediately after the performance of d-PCI, and the 30-day clinical outcomes were evaluated prospectively. The incidence of restoration of normal coronary flow in the IRA was 83.6%. Three baseline angiographic morphologic features indicating high-burden thrombus formation, including (1) the cutoff pattern of occlusion in the IRA (p = 0.0001), (2) the accumulated thrombus proximal to the occlusion (p = 0.0001), and (3) a reference lumen diameter of the IRA of > or = 4.0 mm (p = 0.001), were independent predictors of combined slow flow and no reflow. In stratified analysis, the rates of slow flow and no reflow after d-PCI rose rapidly as the number of independent predictors increased (0 predictors, 3.8%; 1 predictor, 29.0%; and 2 predictors, 70.6%). The overall 30-day mortality rate was 6.7%. The mortality rate was significantly higher in patients with TIMI flow lower than or equal to grade 2 than in those with TIMI grade 3 flow (15% vs 1.3%, respectively; p = 0.003).
  
  
  CONCLUSIONS
  Tirofiban did not provide additional clinical benefits when administered in conjunction with d-PCI for AMI, even in the subgroup of patients with a high-burden thrombus. Those distinct angiographic morphologic features of high-burden thrombus formation remained as independent predictors of combined slow flow and no reflow after d-PCI, and were independent of the use of tirofiban.
authors.affiliation: Division of Cardiology, Chang Gung Memorial Hospital, Kaohsiung, 123 Ta Pei Road, Niao Sung Hsiang, Kaohsiung Hsien, 83301 Taiwan, Republic of China.
authors.forename: Hon-Kan
authors.initials: HK
authors.lastname: Yip
authors.forename: Chiung-Jen
authors.initials: CJ
authors.lastname: Wu
authors.forename: Hsueh-Wen
authors.initials: HW
authors.lastname: Chang
authors.forename: Yuan-Kai
authors.initials: YK
authors.lastname: Hsieh
authors.forename: Chih-Yuan
authors.initials: CY
authors.lastname: Fang
authors.forename: Shyh-Ming
authors.initials: SM
authors.lastname: Chen
authors.forename: Mien-Cheng
authors.initials: MC
authors.lastname: Chen
mesh_terms: D000368:Aged; D015906:Angioplasty, Balloon, Coronary; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000187:drug effects*; D003328:Coronary Thrombosis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000401:mortality; D005260:Female; D005343:Fibrinolytic Agents / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000401:mortality; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000037:antagonists & inhibitors; D011292:Premedication; D012008:Recurrence; D015607:Stents; D015996:Survival Rate; D015912:Thrombolytic Therapy; D000077466:Tirofiban; D016896:Treatment Outcome; D014443:Tyrosine / Q000008:administration & dosage* / Q000009:adverse effects / Q000031:analogs & derivatives
chemical_list: D005343:Fibrinolytic Agents; D019038:Platelet Glycoprotein GPIb-IX Complex; D014443:Tyrosine; D000077466:Tirofiban