Association between admission mean platelet volume and coronary patency after thrombolytic therapy for acute myocardial infarction.

OBJECTIVES: High levels of mean platelet volume (MPV) have been shown to be a predictor of poor clinical outcome among survivors of myocardial infarction. We evaluated the association between admission MPV and infarct-related artery (IRA) patency in patients treated with thrombolytic therapy for acute myocardial infarction (AMI).

STUDY DESIGN: We retrospectively evaluated 133 consecutive patients with ST-elevation AMI, who received thrombolytic therapy within 12 hours of chest pain. Sixty-five patients received streptokinase and 68 patients received recombinant tissue-type plasminogen activator, based on the discretion of the physician. Blood samples were taken before thrombolytic therapy and MPV was measured. Coronary angiography was performed within a mean of two days after thrombolytic therapy and the flow in the IRA was assessed with the TIMI flow grade and corrected TIMI frame count (CTFC).

RESULTS: After thrombolytic therapy, TIMI 3 flow was achieved in 62 patients (46.6%), whereas 71 patients (53.4%) had insufficient TIMI flow. Patients with insufficient TIMI flow had a significantly higher mean admission MPV (9.8+/-1.5 fl vs. 8.6+/-1.4 fl; p<0.001) and were more likely to have been given streptokinase (p=0.02). The two groups were similar with respect to the type of IRA and the number of diseased vessels (p>0.05). There was a weak correlation between MPV and CTFC (p=0.01). Multivariate analysis showed MPV (OR 1.871, 95% CI 1.402-2.498; p<0.001) and the type of thrombolytic agent (OR 2.915; 95% CI 1.333-6.374; p=0.007) as independent predictors of insufficient TIMI flow. The receiver operating characteristic analysis yielded a cutoff value of 8.885 fl for MPV to predict insufficient TIMI flow, with sensitivity and specificity being 70.4% and 66.1%, respectively.

CONCLUSION: Our findings show that a higher admission MPV is associated with an increased risk for insufficient TIMI flow in the IRA after thrombolytic therapy for AMI.