Second asymptomatic carotid surgery trial (ACST-2): a randomised comparison of carotid artery stenting versus carotid endarterectomy
Authors: Alison Halliday, Richard Bulbulia, Leo H Bonati, Johanna Chester, Andrea Cradduck-Bamford, Richard Peto, Hongchao Pan, Alison Halliday, Richard Bulbulia, Leo H Bonati, Richard Peto, Hongchao Pan, John Potter, Hans Henning Eckstein, Barbara Farrell, Marcus Flather, Averil Mansfield, Boby Mihaylova, Kazim Rahimi, David Simpson, Dafydd Thomas, Peter Sandercock, Richard Gray, Andrew Molyneux, Cliff P Shearman, Peter Rothwell, Anna Belli, Will Herrington, Parminder Judge, Peter Leopold, Marion Mafham, Michael Gough, Piergiorgio Cao, Sumaira MacDonald, Vasha Bari, Clive Berry, S Bradshaw, Wojciech Brudlo, Alison Clarke, Johanna Chester, Robin Cox, Andrea Cradduck-Bamford, Susan Fathers, Kamran Gaba, Mo Gray, Elizabeth Hayter, Constance Holliday, Rijo Kurien, Michael Lay, Steffi le Conte, Jessica McManus, Zahra Madgwick, Dylan Morris, Andrew Munday, Sandra Pickworth, Wiktor Ostasz, Michiel Poorthuis, Sue Richards, Louisa Teixeira, Sergey Tochlin, Lynda Tully, Carol Wallis, Monique Willet, Alan Young, Renato Casana, Chiara Malloggi, Andrea Odero Jr, Vincenzo Silani, Gianfranco Parati, Giuseppe Malchiodi, Giovanni Malferrari, Francesco Strozzi, Nicola Tusini, Enrico Vecchiati, Gioacchino Coppi, Antonio Lauricella, Roberto Moratto, Roberto Silingardi, Jessica Veronesi, Andrea Zini, Emanuele Ferrero, Michelangelo Ferri, Andrea Gaggiano, Carmelo Labate, Franco Nessi, Daniele Psacharopulo, Andrea Viazzo, Giovanni Malacrida, Daniela Mazzaccaro, Giovanni Meola, Alfredo Modafferi, Giovanni Nano, Maria Teresa Occhiuto, Paolo Righini, Silvia Stegher, Stefano Chiarandini, Filippo Griselli, Sandro Lepidi, Fabio Pozzi Mucelli, Marcello Naccarato, Mario D'Oria, Barbara Ziani, Andrea Stella, Mortalla Dieng, Gianluca Faggioli, Mauro Gargiulo, Sergio Palermo, Rodolfo Pini, Giovanni Maria Puddu, Andrea Vacirca, Domenico Angiletta, Claudio Desantis, Davide Marinazzo, Giovanni Mastrangelo, Guido Regina, Raffaele Pulli, Paolo Bianchi, Lea Cireni, Elisabetta Coppi, Rocco Pizzirusso, Filippo Scalise, Giovanni Sorropago, Valerio Tolva, Valeria Caso, Enrico Cieri, Paola DeRango, Luca Farchioni, Giacomo Isernia, Massimo Lenti, Gian Battista Parlani, Guglielmo Pupo, Grazia Pula, Gioele Simonte, Fabio Verzini, Federico Carimati, Maria Luisa Delodovici, Federico Fontana, Gabriele Piffaretti, Matteo Tozzi, Efrem Civilini, Giorgio Poletto, Bernhard Reimers, Barbara Praquin, Sonia Ronchey, Laura Capoccia, Wassim Mansour, Enrico Sbarigia, Francesco Speziale, Pasqualino Sirignano, Danilo Toni, Roberto Galeotti, Vincenzo Gasbarro, Francesco Mascoli, Tiberio Rocca, Elpiniki Tsolaki, Giulia Bernardini, Ester DeMarco, Alessia Giaquinta, Francesco Patti, Massimiliano Veroux, Pierfrancesco Veroux, Carla Virgilio, Nicola Mangialardi, Matteo Orrico, Vincenzo Di Lazzaro, Nunzio Montelione, Francesco Spinelli, Francesco Stilo, Carlo Cernetti, Sandro Irsara, Giuseppe Maccarrone, Diego Tonello, Adriana Visonà, Beniamino Zalunardo, Emiliano Chisci, Stefano Michelagnoli, Nicola Troisi, Maela Masato, Massimo Dei Negri, Andrea Pacchioni, Salvatore Saccà, Giovanni Amatucci, Alfredo Cannizzaro, Federico Accrocca, Cesare Ambrogi, Renzo Barbazza, Giustino Marcucci, Andrea Siani, Guido Bajardi, Giovanni Savettieri, Angelo Argentieri, Riccardo Corbetta, Attilio Odero, Pietro Quaretti, Federico Z Thyrion, Alessandro Cappelli, Domenico Benevento, Gianmarco De Donato, Maria Agnese Mele, Giancarlo Palasciano, Daniela Pieragalli, Alessandro Rossi, Carlo Setacci, Francesco Setacci, Domenico Palombo, Maria Cecilia Perfumo, Edoardo Martelli, Aldo Paolucci, Santi Trimarchi, Viviana Grassi, Luigi Grimaldi, Giuliana La Rosa, Domenico Mirabella, Matteo Scialabba, Leonildo Sichel, Costantino L D'Angelo, Gian Franco Fadda, Holta Kasemi, Mario Marino, Francesco Burzotta, Francesco Alberto Codispoti, Angela Ferrante, Giovanni Tinelli, Yamume Tshomba, Claudio Vincenzoni, Deborah Amis, Dawn Anderson, Martin Catterson, Mike Clarke, Michelle Davis, Anand Dixit, Alexander Dyker, Gary Ford, Ralph Jackson, Sreevalsan Kappadath, David Lambert, Tim Lees, Stephen Louw, James McCaslin, Noala Parr, Rebecca Robson, Gerard Stansby, Lucy Wales, Vera Wealleans, Lesley Wilson, Michael Wyatt, Hardeep Baht, Ibrahim Balogun, Ilse Burger, Tracy Cosier, Linda Cowie, Gunaratnam Gunathilagan, David Hargroves, Robert Insall, Sally Jones, Hannah Rudenko, Natasha Schumacher, Jawaharlal Senaratne, George Thomas, Audrey Thomson, Tom Webb, Ellen Brown, Bernard Esisi, Ali Mehrzad, Shane MacSweeney, Norman McConachie, Alison Southam, Wayne Sunman, Ahmed Abdul-Hamiq, Jenny Bryce, Ian Chetter, Duncan Ettles, Raghuram Lakshminarayan, Kim Mitchelson, Christopher Rhymes, Graham Robinson, Paul Scott, Alison Vickers, Ray Ashleigh, Stephen Butterfield, Ed Gamble, Jonathan Ghosh, Charles N McCollum, Mark Welch, Sarah Welsh, Leszek Wolowczyk, Mary Donnelly, Stephen D'Souza, Anselm A Egun, Bindu Gregary, Thomas Joseph, Christine Kelly, Shuja Punekar, M Asad Rahi, Sonia Raj, Dare Seriki, George Thomson, James Brown, Ragunath Durairajan, Iris Grunwald, Paul Guyler, Paula Harman, Matthew Jakeways, Christopher Khuoge, Ashish Kundu, Thayalini Loganathan, Nisha Menon, Raji O Prabakaran, Devesh Sinha, Vicky Thompson, Sharon Tysoe, Dennis Briley, Chris Darby, Linda Hands, Dominic Howard, Wilhelm Kuker, Ursula Schulz, Rachel Teal, David Barer, Andrew Brown, Susan Crawford, Paul Dunlop, Ramesh Krishnamurthy, Nikhil Majmudar, Duncan Mitchell, Min P Myint, Richard O'Brien, Janice O'Connell, Naweed Sattar, Shanmugam Vetrivel, Jonathan Beard, Trevor Cleveland, Peter Gaines, John Humphreys, Alison Jenkins, Craig King, Daniel Kusuma, Ralph Lindert, Robbie Lonsdale, Raj Nair, Shah Nawaz, Faith Okhuoya, Douglas Turner, Graham Venables, Paul Dorman, Andrea Hughes, Deborah Jones, David Mendelow, Helen Rodgers, Aidas Raudoniitis, Peter Enevoldson, Hans Nahser, Imelda O'Brien, Francesco Torella, Dave Watling, Richard White, Pauline Brown, Dipankar Dutta, Lorraine Emerson, Paula Hilltout, Sachin Kulkarni, Jackie Morrison, Keith Poskitt, Fiona Slim, Sarah Smith, Amanda Tyler, Joanne Waldron, Mark Whyman, Milda Bajoriene, Lucy Baker, Amanda Colston, Bekky Eliot-Jones, Gita Gramizadeh, Catherine Lewis-Clarke, Laura McCafferty, Deborah Oliver, Debbie Palmer, Abhijeet Patil, Suzannah Pegler, Gopi Ramadurai, Aisling Roberts, Tracey Sargent, Shivaprasad Siddegowda, Ravi Singh-Ranger, Akintunde Williams, Lucy Williams, Steve Windebank, Tadas Zuromskis, Lanka Alwis, Jane Angus, Asaipillai Asokanathan, Caroline Fornolles, Diana Hardy, Sophy Hunte, Frances Justin, Duke Phiri, Marie Mitabouana-Kibou, Lakshmanan Sekaran, Sakthivel Sethuraman, Margaret L Tate, Joyce Akyea-Mensah, Stephen Ball, Angela Chrisopoulou, Elizabeth Keene, Alison Phair, Steven Rogers, John V Smyth, Colin Bicknell, Jeremy Chataway, Nicholas Cheshire, Andrew Clifton, Caroline Eley, Richard Gibbs, Mohammad Hamady, Beth Hazel, Alex James, Michael Jenkins, Nyma Khanom, Austin Lacey, Maz Mireskandari, Joanna O'Reilly, Antony Pereira, Tina Sachs, John Wolfe, Ellen Brown, Philip Davey, Gill Rogers, Gemma Smith, Gareth Tervit, Ian Nichol, Andrew Parry, Gavin Young, Simon Ashley, James Barwell, Francis Dix, Azlisham M Nor, Chris Parry, Angela Birt, Paul Davies, Jim George, Anne Graham, Leon Jonker, Thomas Joseph, Nicci Kelsall, Caroline Potts, Toni Wilson, Andrew Clifton, Jamie Crinnion, Larissa Cuenoud, Nikola Aleksic, Srdan Babic, Nenad Ilijevski, Đorde Radak, Dragan Sagic, Slobodan Tanaskovic, Momcilo Colic, Vladimir Cvetic, Lazar Davidovic, Dejana R Jovanovic, Igor Koncar, Perica Mutavdžic, Miloš Sladojevic, Ivan Tomic, Eike S Debus, Ulrich Grzyska, Dagmar Otto, Götz Thomalla, Jessica Barlinn, Johannes Gerber, Kathrin Haase, Christian Hartmann, Stefan Ludwig, Volker Pütz, Christian Reeps, Christine Schmidt, Norbert Weiss, Sebastian Werth, Simon Winzer, Janine Gemper, Albrecht Günther, Bianka Heiling, Elisabeth Jochmann, Panagiota Karvouniari, Carsten Klingner, Thomas Mayer, Julia Schubert, Friederike Schulze-Hartung, Jürgen Zanow, Yvonne Bausback, Franka Borger, Spiridon Botsios, Daniela Branzan, Sven Bräunlich, Henryk Hölzer, Janin Lenzer, Christopher Piorkowski, Nadine Richter, Johannes Schuster, Dierk Scheinert, Andrej Schmidt, Holger Staab, Matthias Ulrich, Martin Werner, Hermann Berger, Gábor Biró, Hans-Henning Eckstein, Michael Kallmayer, Kornelia Kreiser, Alexander Zimmermann, Bärbel Berekoven, Klaus Frerker, Vera Gordon, Giovanni Torsello, Sebastian Arnold, Cora Dienel, Martin Storck, Bernhard Biermaier, Hans Martin Gissler, Christof Klötzsch, Tomas Pfeiffer, Ralph Schneider, Leander Söhl, Michael Wennrich, Angelika Alonso, Michael Keese, Christoph Groden, Andreas Cöster, Andreas Engelhardt, Christoph-Maria Ratusinski, Bengt Berg, Martin Delle, Johan Formgren, Peter Gillgren, Lotta Jarl, Torbjörn B Kall, Peter Konrad, Niklas Nyman, Claes Skiöldebrand, Johnny Steuer, Rabbe Takolander, Jonas Malmstedt, Stefan Acosta, Katarina Björses, Kerstin Brandt, Nuno Dias, Anders Gottsäter, Jan Holst, Thorarinn Kristmundsson, Tobias Kühme, Tilo Kölbel, Bengt Lindblad, Mats Lindh, Martin Malina, Tomas Ohrlander, Tim Resch, Viola Rönnle, Björn Sonesson, Margareta Warvsten, Zbigniew Zdanowski, Erik Campbell, Per Kjellin, Hans Lindgren, Johan Nyberg, Björn Petersen, Gunnar Plate, Håkan Pärsson, Peter Qvarfordt, Pavel Ignatenko, Andrey Karpenko, Vladimir Starodubtsev, Mikhail A Chernyavsky, Maria S Golovkova, Boris B Komakha, Nikolay N Zherdev, Andrey Belyasnik, Pavel Chechulov, Dmitry Kandyba, Igor Stepanishchev, Csaba Csobay-Novák, Edit Dósa, László Entz, Balázs Nemes, Zoltán Szeberin, Pál Barzó, Mihaly Bodosi, Eniko Fákó, Béla Fülöp, Tamás Németh, Szilárd Pazdernyik, Krisztina Skoba, Erika Vörös, Eleni Chatzinikou, Athanasios Giannoukas, Christos Karathanos, Stylianos Koutsias, Georgios Kouvelos, Miltiadis Matsagkas, Styliani Ralli, Christos Rountas, Nikolaos Rousas, Konstantinos Spanos, Elias Brountzos, John D Kakisis, Andreas Lazaris, Konstantinos G Moulakakis, Leonidas Stefanis, Georgios Tsivgoulis, Spyros Vasdekis, Constantine N Antonopoulos, Ion Bellenis, Dimitrios Maras, Antonios Polydorou, Victoria Polydorou, Antonios Tavernarakis, Nikolaos Ioannou, Maria Terzoudi, Miltos Lazarides, Michalis Mantatzis, Kostas Vadikolias, Lukasz Dzieciuchowicz, Marcin Gabriel, Zbigniew Krasinski, Grzegorz Oszkinis, Fryderyk Pukacki, Maciej Slowinski, Michal-Goran Stanišic, Ryszard Staniszewski, Jolanta Tomczak, Maciej Zielinski, Piotr Myrcha, Dorota Rózanski, Stanislaw Drelichowski, Wojciech Iwanowski, Katarzyna Koncewicz, Pawel Bialek, Zbigniew Biejat, Wojciech Czepel, Anna Czlonkowska, Anatol Dowzenko, Julia Jedrzejewska, Adam Kobayashi, Jerzy Leszczynski, Andrzej Malek, Jerzy Polanski, Robert Proczka, Maciej Skorski, Mieczyslaw Szostek, Piotr Andziak, Maciej Dratwicki, Robert Gil, Miroslaw Nowicki, Jaroslaw Pniewski, Jaroslaw Rzezak, Piotr Seweryniak, Pawel Dabek, Michal Juszynski, Grzegorz Madycki, Bartosz Pacewski, Witold Raciborski, Piotr Slowinski, Walerian Staszkiewicz, Martin Bombic, Vladimír Chlouba, Jirí Fiedler, Karel Hes, Petr Koštál, Jindrich Sova, Zdenek Kríž, Mojmír Prívara, Michal Reif, Robert Staffa, Robert Vlachovský, Bohuslav Vojtíšek, Tomáš Hrbác, Martin Kuliha, Václav Procházka, Martin Roubec, David Školoudík, David Netuka, Anna Šteklácová, Vladimír Beneš III, Pavel Buchvald, Ladislav Endrych, Miroslav Šercl, Walter Campos Jr, Ivan B Casella, Nelson de Luccia, André E V Estenssoro, Calógero Presti, Pedro Puech-Leão, Celso R B Neves, Erasmo S da Silva, Cid J Sitrângulo Jr, José A T Monteiro, Gisela Tinone, Marcelo Bellini Dalio, Edwaldo E Joviliano, Octávio M Pontes Neto, Mauricio Serra Ribeiro, Patrick Cras, Jeroen M H Hendriks, Mieke Hoppenbrouwers, Patrick Lauwers, Caroline Loos, Laetitia Yperzeele, Mia Geenens, Dimitri Hemelsoet, Isabelle van Herzeele, Frank Vermassen, Parla Astarci, Frank Hammer, Valérie Lacroix, André Peeters, Robert Verhelst, Silvana Cirelli, Pol Dormal, Annelies Grimonprez, Bart Lambrecht, Philipe Lerut, Eddy Thues, Guy De Koster, Quentin Desiron, Alain Maertens de Noordhout, Danielle Malmendier, Mireille Massoz, Georges Saad, Marc Bosiers, Joren Callaert, Koen Deloose, Estrella Blanco Cañibano, Beatriz García Fresnillo, Mercedes Guerra Requena, Pilar C Morata Barrado, Miguel Muela Méndez, Antonio Yusta Izquierdo, Fernando Aparici Robles, Paula Blanes Orti, Luis García Dominguez, Rafael Martínez López, Manuel Miralles Hernández, José I Tembl Ferrairo, Ángel Chamorro, Juan Macho, Víctor Obach, Vincent Riambau, Luis San Román, Frank J Ahlhelm, Kristine Blackham, Stefan Engelter, Thomas Eugster, Henrik Gensicke, Lorenz Gürke, Philippe Lyrer, Luigi Mariani, Marina Maurer, Edin Mujagic, Mandy Müller, Marios Psychogios, Peter Stierli, Christoph Stippich, Christopher Traenka, Thomas Wolff, Benjamin Wagner, Martina M Wiegert, Sandra Clarke, Michael Diepers, Ernst Gröchenig, Lorenz Gürke, Philipp Gruber, Andrej Isaak, Timo Kahles, Regula Marti, Krassen Nedeltchev, Luca Remonda, Peter Stierli, Nadir Tissira, Martina Valença Falcão, Gert J de Borst, Rob H Lo, Frans L Moll, Raechel Toorop, Bart H van der Worp, Evert J Vonken, Jaap L Kappelle, Ommid Jahrome, Floris Vos, Wouter Schuiling, Hendrik van Overhagen, Rudolf W M Keunen, Bob Knippenberg, Jan J Wever, Jan W Lardenoije, Michel Reijnen, Luuk Smeets, Steven van Sterkenburg, Gustav Fraedrich, Elke Gizewski, Ingrid Gruber, Michael Knoflach, Stefan Kiechl, Barbara Rantner, Timur Abdulamit, Patrice Bergeron, Raymond Padovani, Jean-Christophe Trastour, Jean-Marie Cardon, Anne Le Gallou-Wittenberg, Eric Allaire, Jean-Pierre Becquemin, Frédéric Cochennec-Paliwoda, Pascal Desgranges, Hassan Hosseini, Hicham Kobeiter, Jean Marzelle, Mohammed A Almekhlafi, Simerpreet Bal, Phillip A Barber, Shelagh B Coutts, Andrew M Demchuk, Muneer Eesa, Michelle Gillies, Mayank Goyal, Michael D Hill, Mark E Hudon, Anitha Jambula, Carol Kenney, Gary Klein, Marie McClelland, Alim Mitha, Bijoy K Menon, William F Morrish, Steven Peters, Karla J Ryckborst, Greg Samis, Supriya Save, Eric E Smith, Peter Stys, Suresh Subramaniam, Garnette R Sutherland, Tim Watson, John H Wong, L Zimmel, Vojko Flis, Jože Matela, Kazimir Miksic, Franko Milotic, Božidar Mrdja, Barbara Stirn, Erih Tetickovic, Mladen Gasparini, Anton Grad, Ingrid Kompara, Zoren Miloševic, Veronika Palmiste, Toomas Toomsoo, Balzhan Aidashova, Nursultan Kospanov, Roman Lyssenko, Daulet Mussagaliev, Rafi Beyar, Aaron Hoffman, Tony Karram, Arthur Kerner, Eugenia Nikolsky, Samy Nitecki, Silva Andonova, Chavdar Bachvarov, Vesko Petrov, Ivan Cvjetko, Vinko Vidjak, Damir Halužan, Mladen Petrunic, Bao Liu, Chang-Wei Liu, Daniel Bartko, Peter Beno, František Rusnák, Kamil Zelenák, Masayuki Ezura, Takashi Inoue, Naoto Kimura, Ryushi Kondo, Yasushi Matsumoto, Hiroaki Shimizu, Hidenori Endo, Eisuke Furui, Søren Bakke, Kristen Krohg-Sørensen, Terje Nome, Mona Skjelland, Bjørn Tennøe, João Albuquerque e Castro, Gonçalo Alves, Frederico Bastos Gonçalves, José de Aragão Morais, Ana C Garcia, Hugo Valentim, Leonor Vasconcelos, Fernando Belcastro, Fernando Cura, Patricio Zaefferer, Foad Abd-Allah, Mohamed H Eldessoki, Hussein Heshmat Kassem, Haytham Soliman Gharieb, Mary P Colgan, Syed N Haider, Joe Harbison, Prakash Madhavan, Dermot Moore, Gregor Shanik, Viviane Kazan, Munier Nazzal, Vicki Ramsey-Williams
Journal: The Lancet (2021)

BackgroundAmong asymptomatic patients with severe carotid artery stenosis but no recent stroke or transient cerebral ischaemia, either carotid artery stenting (CAS) or carotid endarterectomy (CEA) can restore patency and reduce long-term stroke risks. However, from recent national registry data, each option causes about 1% procedural risk of disabling stroke or death. Comparison of their long-term protective effects requires large-scale randomised evidence.MethodsACST-2 is an international multicentre randomised trial of CAS versus CEA among asymptomatic patients with severe stenosis thought to require intervention, interpreted with all other relevant trials. Patients were eligible if they had severe unilateral or bilateral carotid artery stenosis and both doctor and patient agreed that a carotid procedure should be undertaken, but they were substantially uncertain which one to choose. Patients were randomly allocated to CAS or CEA and followed up at 1 month and then annually, for a mean 5 years. Procedural events were those within 30 days of the intervention. Intention-to-treat analyses are provided. Analyses including procedural hazards use tabular methods. Analyses and meta-analyses of non-procedural strokes use Kaplan-Meier and log-rank methods. The trial is registered with the ISRCTN registry, ISRCTN21144362.FindingsBetween Jan 15, 2008, and Dec 31, 2020, 3625 patients in 130 centres were randomly allocated, 1811 to CAS and 1814 to CEA, with good compliance, good medical therapy and a mean 5 years of follow-up. Overall, 1% had disabling stroke or death procedurally (15 allocated to CAS and 18 to CEA) and 2% had non-disabling procedural stroke (48 allocated to CAS and 29 to CEA). Kaplan-Meier estimates of 5-year non-procedural stroke were 2·5% in each group for fatal or disabling stroke, and 5·3% with CAS versus 4·5% with CEA for any stroke (rate ratio [RR] 1·16, 95% CI 0·86–1·57; p=0·33). Combining RRs for any non-procedural stroke in all CAS versus CEA trials, the RR was similar in symptomatic and asymptomatic patients (overall RR 1·11, 95% CI 0·91–1·32; p=0·21).InterpretationSerious complications are similarly uncommon after competent CAS and CEA, and the long-term effects of these two carotid artery procedures on fatal or disabling stroke are comparable.FundingUK Medical Research Council and Health Technology Assessment Programme.