StudyObjective: Toassess the rapidity and amount of myocardial improvement with routine use ofsustained mechanical aspiration thrombectomy in acute coronary syndrome (ACS)patients with a large thrombus burden (LTB) as per AVIS protocolDesign: This is a prospective observationalstudy. Setting: Multicenter tertiary healthcare centersin North India. 

Participants: ACS patients with LTB recommendedfor percutaneous coronary intervention (PCI) Intervention: Routine upfront sustainedmechanical aspiration thrombectomy with The Indigo^™ system CAT^™RX (Penumbra Inc., Alameda, CA) before primary PCI followed by CoronaryImaging prior to stenting, if needed as per AVIS protocol. This was  compared with a similar group of patients whounderwent Primary PCI for Acute MI as per standard of care, with or withoutimaging and manual thromboaspiration.Mainoutcome:Primary outcomes included improvement in thrombolysis in myocardial infarction(TIMI) flow, TIMI thrombus grade, and myocardial blush grade (MBG). Clinicaloutcomes (death, recurrent MI, stroke) and infarct zone size and improvement inLV function were recorded at baseline and 6 months. OCT parameters likebaseline plaque morphology & post procedure stent expansion & PRATIthrombus grade were documented. Additional in hospital parameters like time toST segment resolution, improvement in Killip Class Status at 6 hours & 24hours, acute kidney injury.

Among 350 patients (median age 52years, 74% male), most had grade 5 thrombus (88%), MBG grade 0 (88%), and TIMIgrade 0 flow (86%) at baseline. Half of the patients (n=175) underwent PAMIwith the AVIS protocol. After the procedure, significant improvements wereobserved in TIMI flow, TIMI thrombus grade, and MBG (p<0.001). There was asignificant lesser infarct size, greater increase in the mean left ventricularejection fraction from baseline to six month follow up (3.2% vs. 7.8%;p<0.001). More number of patients achieved >70% ST segment resolution at1 hour (68% versus 90%) and speed of ST segment resolution, improvement ofKillip Class paralleled MBG (correlation on multivariate analysis, r = 0.93).Thrombus debulking, as evidenced by residual thrombus grade (PRATI thrombusgrade <5) predicted greater improvement in LV function. 

Sustainedmechanical aspiration thrombectomy with AVIS protocol effectively removed clotsand aided in optimal myocardial perfusion in ACS patients with LTB. Thisprotocol tends to lower myocardial damage and helps achieve faster and moreprecise results and sequential application of imaging can help in mechanisticapproach to ACS and lesser stent length in background of modern antiplatelet& lipid lowering therapy.