Role of tirofiban (GpIIbIIIa Inhibitors) in acute ST elevation myocardial infarction in thrombolysis ineligible patients.

Background: Coronary artery disease has been increasing by epidemic proportions in this part of the subcontinent. We have a set up where majority of referrals are from remote areas and catheterization facilities are not available round the clock. Although routine percutaneous revascularizations are being done with a high success rate, the institute still lacks round the clock technical support for a primary PCI. So fibrinolysis remains the major treatment option for all such patients of STEMI. Unfortunately for the reasons stated above quite a large fraction of patients are ineligible for thrombolysis. So a thought arose as to how these patients could be benefited. Objectives: To study the effect of Tirofiban (a GpIIbIIIa inhibitor) on clinical outcome and TIMI flow/TMP grade at coronary angiography in patients of acute ST elevation myocardial infarction, ineligible for fibrinolysis. Methods: In this prospective randomized placebo controlled study, 50 (25 each) cases were randomized to receive either tirofiban or placebo infusion (in the form of normal saline). Patients were taken up for coronary angiography within the first week, post onset of myocardial infarction. The primary end points were the angiographic TIMI and TMP grades and presence of thrombus in the infarct related artery. The main secondary endpoints were chest pain resolution, ST segment resolution on ECG and angina/MI recurrence. Results: Tirofiban at a dose of 10mcg/kg bolus and an infusion for 24 hours @ 0.15mcg/kg/min was associated with a significant improvement in TIMI and TMP grades as compared to the placebo group (P<0.001/OR 176 and P<0.001/OR 73.5 respectively). Also, there was a lower incidence of thrombus in the infarct related artery in the tirofiban group (12 vs 64%, p< 0.00015, OR 13.5). In addition there was a higher and prompter resolution of chest pain (p< 0.0001), lesser angina recurrence (p< 0.03) and a higher percentage of significant ST segment resolution on ECG (p< 0.004) in the study group as compared to the control group. Conclusions: The use of tirofiban (a GpIIbIIIa inhibitor) in patients of acute STEMI ineligible for fibrinolysis is associated with a higher rate of IRA (infarct related artery) patency, increased and prompter resolution of chest pain, better ST segment resolution on ECG, and a decreased angina recurrence