ABC | Volume 111, Nº4, Octuber 2018

Review Article Risk-Benefit Assessment of Carotid Revascularization Pedro Piccaro de Oliveira, José Luiz da Costa Vieira, Raphael Boesche Guimarães, Eduardo Dytz Almeida, Simone Louise Savaris, Vera Lucia Portal Instituto de Cardiologia - Fundação Universitária de Cardiologia (IC/FUC), Porto Alegre, RS - Brazil Mailing Address: Vera Lucia Portal • Rua Luciana de Abreu, 471 sala 603. Postal Code 90570-080, Moinhos de Vento, Porto Alegre, RS – Brazil E-mail: veraportal@cardiol.br , editoracao-pc@cardiologia.org.br , veraportal. pesquisa@gmail.com Manuscript received May 10, 2018, revised manuscript June 21, 2018, accepted July 02, 2018 DOI: 10.5935/abc.20180208 Keywords Carotid Artery Diseases; Atherosclerosis; Endarterectomy, Carotid; Stroke; Indicators of Morbidity and Mortality; Risk Assessment Abstract Severe carotid atherosclerotic disease is responsible for 14% of all strokes, which result in a high rate of morbidity and mortality. In recent years, advances in clinical treatment of cardiovascular diseases have resulted in a significant decrease in mortality due to these causes. To review the main studies on carotid revascularization, evaluating the relationship between risks and benefits of this procedure. The data reviewed show that, for a net benefit, carotid intervention should only be performed in cases of a periprocedural risk of less than 6% in symptomatic patients. The medical therapy significantly reduced the revascularization net benefit ratio for stroke prevention in asymptomatic patients. Real life registries indicate that carotid stenting is associated with a greater periprocedural risk. The operator annual procedure volume and patient age has an important influence in the rate of stroke and death after carotid stenting. Symptomatic patients have a higher incidence of death and stroke after the procedure. Revascularization has the greatest benefit in the first weeks of the event. There is a discrepancy in the scientific literature about carotid revascularization and/or clinical treatment, both in primary and secondary prevention of patients with carotid artery injury. The identification of patients who will really benefit is a dynamic process subject to constant review. Introduction Carotid endarterectomy was introduced in 1954 for stroke prevention, but it wasn`t until the 90`s that the first randomized clinical trials (RCTs) evaluated its effectiveness. The first published RCTs on the subject were NASCET (1991), VACS (1991) and ECST (1993), all of which demonstrated benefit of surgical intervention in secondary prevention setting. 1-3 Regarding primary prevention, a small RCT was published in 1993 4 followed by two larger ones (ACAS, 1995; ACST, 2004) 5,6 that demonstrated a greater benefit of surgical intervention when compared to optimal medical treatment. Several studies comparing carotid angioplasty and stenting (CAS) and carotid endarterectomy (CEA) were published in the 2000's, leading to a recommendation for routine use of embolic protection devices. Five clinical trials (SAPPHIRE, 7 EVA-3S, 8 SPACE, 9 CREST 10 and ACT I 11 ) found that percutaneous intervention is an alternative to surgical intervention in both symptomatic and asymptomatic patients. On the other hand, the ICSS trial found a higher risk of stroke and death after CAS in symptomatic patients. 12 Paraskevas et al. 13 compiled data from several “real-world” registries in a systematic review and found that percutaneous procedures resulted in higher rates stroke and death when compared do CEA, albeit with conflicting results from each registry. 13 While many studies have focused on comparing the two modalities of intervention, the definition of optimal medical treatment (OMT) has evolved and currently reduces relative risk of stroke related to extracranial atherosclerosis by up to 70%. 1,2,10,14 Ascertaining risk-benefit ratio between CAS and CEA is challenging. There are thirty-four international guidelines on the subject, with significant variability regarding choice of carotid revascularization procedure. 15 This review aims to provide an updated risk-benefit assessment across the different treatment options (CEA, CAS and OMT) for symptomatic and asymptomatic carotid stenosis. Methods This article was based on a literature review carried out through an online search of the main articles and guidelines published in the last 30 years, aiming to evaluate the relationship between risk and benefit of carotid revascularization. Due to the differences in the indexing processes in the bibliographic databases, we opted for the search for free terms, without the use of controlled vocabulary (descriptors). Results Stroke is the third cause of death in theWesternworld and the leading cause of permanent neurological disability. 16 About 85% of strokes are ischemic in origin and 80% of non-hemorrhagic strokes affect brain areas irrigated by carotid arteries. Most strokes are due to thromboembolismof atherosclerotic lesions in internal carotid arteries. Usually, these occur in smaller carotid plaques with lower than 50% stenosis, considered non-surgical stenosis. The remaining cases are considered stenotic plaques that should be evaluated for surgical treatment. 14 Evolution of optimal medical treatment Pivotal studies on the incidence of stroke in patients with severe symptomatic carotid stenosis, without carotid 618