Antiplatelet therapy is the mainstay of pharmacologic treatment to prevent thrombotic or ischemic events in patients with coronary artery disease treated with percutaneous coronary intervention and those treated medically for an acute coronary syndrome. The use of antiplatelet therapy comes at the expense of an increased risk of bleeding complications. Defining the optimal intensity of platelet inhibition according to the clinical presentation of atherosclerotic cardiovascular disease and individual patient factors is a clinical challenge. Modulation of antiplatelet therapy is a medical action that is frequently performed to balance the risk of thrombotic or ischemic events and the risk of bleeding. This aim may be achieved by reducing (ie, de-escalation) or increasing (ie, escalation) the intensity of platelet inhibition by changing the type, dose, or number of antiplatelet drugs. Because de-escalation or escalation can be achieved in different ways, with a number of emerging approaches, confusion arises with terminologies that are often used interchangeably. To address this issue, this Academic Research Consortium collaboration provides an overview and definitions of different strategies of antiplatelet therapy modulation for patients with coronary artery disease, including but not limited to those undergoing percutaneous coronary intervention, and consensus statements on standardized definitions., Competing Interests: Disclosures Dr Capodanno reports speaker or consulting fees from Amgen, Arena, Daiichi Sankyo, Sanofi, and Terumo; and institutional fees from Medtronic. Dr Mehran reports institutional research payments from Abbott, Abiomed, Alleviant Medical, Amgen, AM-Pharma, Arena, AstraZeneca, Atricure, Bayer, Biosensors, Biotronik, Boston Scientific, Bristol Myers Squibb, CardiaWave, CeloNova, Chiesi, Concept Medical, CSL Behring, Cytosorbents, Daiichi Sankyo, Element Science, Faraday, Filterlex Medical, Humacyte, Idorsia Pharmaceuticals, Janssen, Mediasphere, Medtelligence, Medtronic, Novartis, OrbusNeich, Penumbra, PhaseBio, Philips, Pi-Cardia, PLx Pharma, Protembis, RenalPro, RM Global, Shockwave, Vivasure, and Zoll; personal fees from Cine-Med Research, Ionis Pharmaceuticals, Novartis, Novo Nordisk, Vectura, and WebMD; equity <1% in Applied Therapeutics, Elixir Medical, Stel, and ControlRad (spouse); and roles with the American Medical Association (Scientific Advisory Board, JAMA Cardiology Associate editor), American College of Cardiology (board of trustees member, member clinical trials research program), and Society for Cardiovascular Angiography & Interventions (Women in Innovations committee member; faculty Cardiac Research Foundation; no fee). Dr Baber discloses honoraria from Amgen, AstraZeneca, Boston Scientific, and Abbott Vascular. Dr Bhatt discloses the following relationships: advisory board: Angiowave, Bayer, Boehringer Ingelheim, Cardax, CellProthera, Cereno Scientific, Elsevier Practice Update Cardiology, High Enroll, Janssen, Level Ex, McKinsey, Medscape Cardiology, Merck, MyoKardia, NirvaMed, Novo Nordisk, PhaseBio, PLx Pharma, Regado Biosciences, and Stasys; board of directors: Angiowave (stock options), Boston VA Research Institute, Bristol Myers Squibb (stock), DRS.LINQ (stock options), High Enroll (stock), Society of Cardiovascular Patient Care, and TobeSoft; chair: inaugural chair, American Heart Association Quality Oversight Committee; consultant: Broadview Ventures and Hims; data monitoring committees: Acesion Pharma, Assistance Publique-Hôpitaux de Paris, Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute, for PORTICO [Portico Re-sheathable Transcatheter Aortic Valve System US IDE Trial], funded by St Jude Medical, now Abbott), Boston Scientific (chair, PEITHO [Pulmonary Embolism Thrombolysis Study]), Cleveland Clinic (including for ExCEED [Centera THV System in Intermediate Risk Patients Who Have Symptomatic, Severe, Calcific, Aortic Stenosis], funded by Edwards), Contego Medical (chair, PERFORMANCE 2 [Protection Against Emboli During Carotid Artery Stenting Using the Neuroguard IEP System]), Duke Clinical Research Institute, Mayo Clinic, Mount Sinai School of Medicine (for ENVISAGE [Edoxaban Compared to Standard Care After Heart Valve Replacement Using a Catheter in Patients With Atrial Fibrillation], funded by Daiichi Sankyo; for ABILITY-DM [Randomized Comparison of Abluminus DES+ Sirolimus-Eluting Stents Versus Everolimus-Eluting Stents in Coronary Artery Disease Patients with Diabetes Mellitus], funded by Concept Medical), Novartis, Population Health Research Institute, and Rutgers University (for the National Institutes of Health–funded MINT [Myocardial Ischemia and Transfusion]); honoraria: American College of Cardiology (Senior Associate Editor, Clinical Trials and News, ACC.org; chair, American College of Cardiology Accreditation Oversight Committee), Arnold and Porter law firm (work related to Sanofi/Bristol Myers Squibb clopidogrel litigation), Baim Institute for Clinical Research (formerly Harvard Clinical Research Institute; RE-DUAL PCI [Evaluation of Dual Therapy With Dabigatran vs Triple Therapy With Warfarin in Patients With Atrial Fibrillation That Undergo a PCI With Stenting] clinical trial steering committee funded by Boehringer Ingelheim; AEGIS-II [Study to Investigate CSL112 in Subjects With Acute Coronary Syndrome] executive committee funded by CSL Behring), Belvoir Publications (Editor-in-Chief, Harvard Heart Letter), Canadian Medical and Surgical Knowledge Translation Research Group (clinical trial steering committees), Cowen and Company, Duke Clinical Research Institute (clinical trial steering committees, including for PRONOUNCE [A Trial Comparing Cardiovascular Safety of Degarelix Versus Leuprolide in Patients With Advanced Prostate Cancer and Cardiovascular Disease], funded by Ferring Pharmaceuticals), HMP Global (editor-in-chief, Journal of Invasive Cardiology), Journal of the American College of Cardiology (guest editor; associate editor), K2P (co-chair, interdisciplinary curriculum), Level Ex, Medtelligence/ReachMD (CME steering committees), MJH Life Sciences, Oakstone CME (course director, Comprehensive Review of Interventional Cardiology), Piper Sandler, Population Health Research Institute (for the COMPASS [Cardiovascular Outcomes for People Using Anticoagulation Strategies] operations committee, publications committee, steering committee, and US national coleader, funded by Bayer), Slack Publications (chief medical editor, Cardiology Today’s Intervention), Society of Cardiovascular Patient Care (secretary/treasurer), WebMD (continuing medical education steering committees), and Wiley (steering committee); other: Clinical Cardiology (deputy editor), National Cardiovascular Data Registry–ACTION Registry Steering Committee (chair), and VA CART (Cardiovascular Assessment, Reporting, and Tracking) Research and Publications Committee (chair); patent: sotagliflozin (named on a patent for sotagliflozin assigned to Brigham and Women’s Hospital, assigned to Lexicon; neither the author nor Brigham and Women’s Hospital receives any income from this patent); research funding: Abbott, Acesion Pharma, Afimmune, Aker Biomarine, Amarin, Amgen, AstraZeneca, Bayer, Beren, Boehringer Ingelheim, Boston Scientific, Bristol Myers Squibb, Cardax, CellProthera, Cereno Scientific, Chiesi, CinCor, Cleerly, CSL Behring, Eisai, Ethicon, Faraday Pharmaceuticals, Ferring Pharmaceuticals, Forest Laboratories, Fractyl, Garmin, HLS Therapeutics, Idorsia, Ironwood, Ischemix, Janssen, Javelin, Lexicon, Lilly, Medtronic, Merck, Moderna, MyoKardia, NirvaMed, Novartis, Novo Nordisk, Owkin, Pfizer, PhaseBio, PLx Pharma, Recardio, Regeneron, Reid Hoffman Foundation, Roche, Sanofi, Stasys, Synaptic, The Medicines Company, Youngene, and 89Bio; royalties: Elsevier (editor, Braunwald’s Heart Disease); site coinvestigator: Abbott, Biotronik, Boston Scientific, CSI, Endotronix, St Jude Medical (now Abbott), Philips, SpectraWAVE, Svelte, and Vascular Solutions; trustee: American College of Cardiology; and unfunded research: FlowCo and Takeda. Dr Capranzano reports speaker fees from Daiichi Sankyo, Amgen, and Bayer. Dr Collet reports grants for the institution, honoraria, or research fees from BMS Pfizer, Medtronic, Boston Scientific, and AstraZeneca. Dr Cuisset reports consulting and lecture fees from Abbott Vascular, Boston Scientific, Edwards, Europa Organisation, Medtronic, Terumo, and Sanofi, and shares from CERC, a health care company. Dr L. De Luca has received consulting fees or honoraria from Amgen, Aspen, AstraZeneca, Bayer, Boehringer Ingelheim, Chiesi, Daiichi Sankyo, Eli Lilly, Menarini, Pfizer/Bristol Myers Squibb, Sanofi, Servier, and The Medicines Company, outside the present work. Dr Farb has received payment as an individual for consulting fee or honoraria from AstraZeneca, Bayer, and Sanofi and institutional payments for grants from PLx Pharma and The Scott R. MacKenzie Foundation. Dr Gibson reports grant support paid to the institution and consulting fees from Johnson & Johnson, Bristol Myers Squibb, CeleCor, Daiichi Sankyo, and Merck. Dr Hahn reports an institutional research grant from the National Evidence-based Healthcare Collaborating Agency, Ministry of Health & Welfare, Korea, and from Abbott Vascular, Biosensors, Boston Scientific, Daiichi Sankyo, Donga-ST, Hanmi Pharmaceutical, and Medtronic Inc. Dr James repots grants to the institution from Amgen, Novartis, Janssen, and AstraZeneca. Dr Lemos reports institutional research funding, unpaid advisory board membership, unpaid membership of the steering/executive/data safety and monitoring group of trials, and unpaid interventional proctorship by Abbott, Corindus, Scitech, Boston Scientific, and Flouit but has not received personal payments by pharmaceutical companies or device manufacturers; being part of Argonauts, an innovation facilitator; and partial support by a grant from The National Council for Scientific and Technological Development (CNPq), Brazil (grant 306677/2019-9). Dr Lopes reports research support from Bristol Myers Squibb, GlaxoSmithKline, Medtronic, and Pfizer and consulting fees from Bayer, Boehringer Ingelheim, Bristol Myers Squibb, Daiichi Sankyo, GlaxoSmithKline, Medtronic, Merck, Pfizer, and Portola. Dr Morice reports being chief executive officer and a shareholder of CERC and a minor shareholder of Electroducer. Dr O’Donoghue reports grants through the hospital from Amgen, Novartis, Janssen, Merck, and AstraZeneca, and honoraria from Amgen, Novartis, AstraZeneca, and Janssen. Dr Serruys reports consultancy fees from SMT, Philips, Novartis, Merillife, and Xeltis. Dr Smits reports institutional research grants from Abbott Vascular and SMT and speaker or consulting honoraria from Abbott Vascular, Microport, and Terumo. Dr Steg reports research grants from Amarin, Bayer, Sanofi, and Servier; he is a speaker or consultant for Amarin, Amgen, AstraZeneca, Bayer, Bristol Myers-Squibb, Janssen, Kowa, Idorsia, Lexicon, Merck, Novartis, Novo Nordisk, PhaseBio, Pfizer, Regeneron, Sanofi, and Servier; he is senior associate editor of Circulation. Dr Storey reports institutional research grants/support and personal fees from AstraZeneca, Cytosorbents, GlyCardial Diagnostics, and Thromboserin and personal fees from Alnylam, Bayer, Bristol Myers Squibb/Pfizer, Chiesi, CSL Behring, Daiichi Sankyo, Hengrui, Idorsia, Intas Pharmaceuticals, Novartis, PhaseBio, and Sanofi Aventis. Dr Valgimigli reports grants and personal fees from Terumo and personal fees from AstraZeneca, Alvimedica/CID, Abbott Vascular, Daiichi Sankyo, Bayer, CoreFLOW, Idorsia Pharmaceuticals Ltd, Universität Basel, Dept Klinische Forschung, Vifor, Bristol Myers Squib SA, Biotronik, Boston Scientific, Medscape, Medtronic, Vesalio, Novartis, Chiesi, ECRI, and PhaseBio. Dr Vranckx received personal fees from Daiichi Sankyo, Bayer AG, CSL Behring, Novartis, and Pfizer-Bristol Meyers Squibb alliance. Dr Windecker reports research, travel, or educational grants to the institution from Abbott, Abiomed, Amgen, AstraZeneca, Bayer, Biotronik, Boehringer Ingelheim, Boston Scientific, Bristol Myers Squibb, Cardinal Health, CardioValve, Corflow Therapeutics, CSL Behring, Daiichi Sankyo, Edwards Lifesciences, Guerbet, InfraRedx, Janssen-Cilag, Johnson & Johnson, Medicure, Medtronic, Merck Sharp & Dohme, Miracor Medical, Novartis, Novo Nordisk, Organon, OrPha Suisse, Pfizer, Polares, Regeneron, Sanofi-Aventis, Servier, Sinomed, Terumo, Vifor, and V-Wave; serves as an advisory board member or member of the steering/executive group of trials funded by Abbott, Abiomed, Amgen, AstraZeneca, Bayer, Boston Scientific, Biotronik, Bristol Myers Squibb, Edwards Lifesciences, Janssen, MedAlliance, Medtronic, Novartis, Polares, Recardio, SINOMED, Terumo, V-Wave, and Xeltis, with payments to the institution but no personal payments; and is a member of the steering/executive committee group of several investigator-initiated trials that receive funding by industry without effect on his personal remuneration. Dr Yeh reports research grants or consulting fees from Abbott Vascular, Boston Scientific, and Medtronic; and consulting fees from Cathworks, Elixir Medical, Shockwave, and Zoll. Dr Angiolillo has received consulting fees or honoraria from Abbott, Amgen, AstraZeneca, Bayer, Biosensors, Boehringer Ingelheim, Bristol Myers Squibb, Chiesi, CSL Behring, Daiichi Sankyo, Eli Lilly, Haemonetics, Janssen, Merck, Novartis, PhaseBio, PLx Pharma, Pfizer, Sanofi, and Vectura, outside the present work; and his institution has received research grants from Amgen, AstraZeneca, Bayer, Biosensors, CeloNova, CSL Behring, Daiichi-Sankyo, Eisai, Eli Lilly, Gilead, Janssen, Matsutani Chemical Industry Co, Merck, Novartis, Osprey Medical, Renal Guard Solutions, and the Scott R. MacKenzie Foundation. The other authors have nothing to disclose.