Abolition of micro embolic signals in symptomatic carotid stenosis using dual antiplatelet therapy

Abstract

Introduction : Micro-Embolic Signals (MES) detected by Trans-Cranial Doppler (TCD) in symptomatic carotid stenosis (CS) are considered a marker of subsequent stroke. We aimed to investigate the role of antiplatelet and antithrombotic agents in abolishing the MES in recently symptomatic CS. Materials and Methods: Transient ischemic attack/stroke patients with 50%CS or unstable carotid plaque, who were prospectively enrolled within 48hours of symptom onset, underwent bilateral middlecerebral artery one-hour TCD emboli monitoring within 48hours. Those with MES underwent second monitoring at 48hours of the initial study. Treatment given during the interval period was recorded. Results: Out of 73 patients enrolled from April 2016 to March 2019, 22 (17 males, mean age 67.4years) had ipsilateral MES on initial TCD (30.1%). Ten were on a single-antiplatelet agent (aspirin/clopidogrel) and one was on dual (aspirin&clopidogrel) therapy prior to this. Single-antiplatelet agent was started after TCD in seven, dual-agents in six and unfractionated-heparin in seven patients. Second TCD showed no MES in 14 patients. Only one out of three on a single antiplatelet agent alone had abolition of MES while all ten patients on dual-antiplatelet agents had a complete suppression (p=0.027,Chi-square test). Although heparin suppressed MES in 5/7 patients, all five had additional dual-agent therapy. MES was not abolished in one patient treated with heparin alone and another one on a combination of heparin and single-antiplatelet agent. Conclusion: Aspirin/Clopidogrel combination is very effective in suppressing arterial emboli in recently symptomatic carotid stenosis whereas unfractionated-heparin, single-antiplatelet agent or their combination is not useful for the same. Keywords: Micro-Embolic Signals, Trans-Cranial Doppler, Carotid stenosis.