Table 1

Definitions and Classification of Restenosis and Stent Thrombosis

Angiographic Restenosis and Classification
Diameter stenosis ≥50%
Type I focal: ≤10 mm in length
 IA articulation or gap
 IB margin
 IC focal body
 ID multifocal
Type 2 diffuse: >10 mm intrastent
Type 3 proliferative: >10 mm extending beyond the stent margins
Type 4 total occlusion: restenotic lesions with TIMI flow grade of 0
Clinical Restenosis: Assessed Objectively as Requirement for Ischemia-Driven Repeat Revascularization
Diameter stenosis ≥50% andone of the following:
 Positive history of recurrent angina pectoris, presumably related to target vessel
 Objective signs of ischemia at rest (ECG changes) or during exercise test (or equivalent), presumably related to target vessel
 Abnormal results of any invasive functional diagnostic test (e.g., coronary flow velocity reserve, FFR <0.80); IVUS minimum cross-sectional area <4 mm2(and <6.0 mm2for left main stem) has been found to correlate with abnormal FFR and need for subsequent TLR (5–7)
TLR with diameter stenosis ≥70% even in absence of the above ischemic signs or symptoms
Stent Thrombosis
Definite stent thrombosis
 Angiographic confirmation of stent thrombosis
  Presence of thrombus that originates in stent or in the segment 5 mm proximal or distal to stent andat least 1 of the following within a 48-h time window
   Acute onset of ischemic symptoms at rest
   New ischemic ECG changes that suggest acute ischemia
   Typical rise and fall in cardiac biomarkers
 Pathologic confirmation of stent thrombosis
  Evidence of recent thrombus within stent determined at autopsy or via examination of tissue retrieved following thrombectomy
 Probable stent thrombosis
  Any unexplained death within first 30 days
  Irrespective of time after index procedure, any MI related to documented acute ischemia in territory of stent thrombosis and in absence of any other obvious cause
 Possible stent thrombosis
  Any unexplained death from 30 days after intracoronary stenting

ECG = electrocardiography; FFR = fractional flow reserve; IVUS = intravascular ultrasound; MI = myocardial infarction; TIMI = Thrombolysis In Myocardial Infarction; TLR = target lesion revascularization.