Should patients with asymptomatic significant carotid stenosis undergo simultaneous carotid and cardiac surgery?

A best evidence topic in cardiovascular surgery was written according to a structured protocol. The question addressed was whether patients with severe asymptomatic carotid and coronary artery diseases should undergo simultaneous carotid endarterectomy (CEA) and coronary artery bypass grafting (CABG). A total of 624 papers were found using the reported search, of which 20 represent the best evidence to answer the clinical question. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study results of these papers are tabulated. Previous cohort studies showed mixed results, while advocating for the necessity of a randomized controlled trial (RCT). A recent RCT showed that patients undergoing prophylactic or simultaneous CEA + CABG had lower rates of stroke (0%) compared with delayed CEA 1-3 months after CABG (7.7%), without significant perioperative mortality difference. This study included patients with unilateral severe (>70%) asymptomatic carotid stenosis requiring CABG. An earlier partly randomized trial also showed better outcomes for patients undergoing simultaneous procedures (P = 0.045). Interestingly, systematic reviews previously failed to show compelling evidence supporting prophylactic CEA. This could be partly due to the fact that these reviews collectively analyse different cohort qualities. Neurological studies have, however, shown reduced cognitive and phonetic quality and function in patients with unilateral and bilateral asymptomatic carotid artery stenosis. Twenty-one RCTs comparing lone carotid artery stenting (CAS) and CEA informed the American Heart Association guidelines, which declared CAS comparable with CEA for symptomatic and asymptomatic carotid stenosis (CS). However, the risk of death/stroke for CAS alone is double that for CEA alone in the acute phase following onset of symptoms, while CEA alone is associated with a doubled risk of myocardial infarction. There is, however, no significant difference for combined 30-day risk of death/stroke/myocardial infarction. Outcomes of hybrid or simultaneous CAS/CABG procedures show comparable results, albeit from rather small cohorts. While current evidence leans towards simultaneous CEA/CABG, the emergence of hybrid operating theatres in various institutions may allow larger cohorts with subsequent significant data on simultaneous CAS/CABG. A randomized controlled trial comparing both approaches would be crucial in informing future updates of existing guidelines.

Should patients with asymptomatic severe mitral regurgitation with good left ventricular function undergo surgical repair?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, 'Does severe asymptomatic mitral regurgitation (MR) require surgery or is watch and wait the optimal strategy?'. Over 103 papers were found using the reported search, and 10 represented the best evidence to answer this clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. No studies in the modern era have shown significant survival benefit for patients undergoing surgery for asymptomatic severe MR if they have good left ventricular (LV) function. The progression rate to surgery on developing symptoms is 10% per year in these patients. Ling et al. reported a 63% incidence of congestive heart failure and 30% incidence of chronic atrial fibrillation (AF) at 10 years for conservative treatment, during which period 90% either underwent surgery or died. In addition, one study of 478 patients with good LV operated on in the 1980s showed a 76% 10-year survival in patients who were NYHA I/II but only a 48% 10-year survival in patients with NYHA III/IV although this group was older and had more AF. Early surgery has very good peri- and postoperative survival rates, and the American Heart Association currently recommend that these patients may be operated on if the chance of repair is >90%. Patients may, therefore, be reassured that either strategy is acceptable.