Long Term Mortality Rate in Patients Treated with Carotid Endarterectomy.

Objective: Carotid endarterectomy (CEA) is an effective surgical method for stroke prevention in selected patients with carotid stenosis. Few contemporary studies report on the long term mortality rate in CEA treated patients, despite continuous changes in medication, diagnostics, and patient selection. Here, the long term mortality rate is described in a well characterised cohort of asymptomatic and symptomatic CEA patients, sex differences evaluated, and mortality ratio compared with the general population.

Methods: This was a two centre, non-randomised, observational study evaluating all cause, long term mortality in CEA patients from Stockholm, Sweden between 1998 and 2017. Death and comorbidities were extracted from national registries and medical records. Cox regression was adapted to analyse associations between clinical characteristics and outcome. Sex differences and standardised mortality ratio (SMR, age and sex matched) were studied.

Results: A total of 1 033 patients were followed for 6.6 ± 4.8 years. Of those, 349 patients died during follow up where the overall mortality rate was similar in asymptomatic and symptomatic patients (34.2% vs. 33.7%, p = .89). Symptomatic disease did not influence the mortality risk (adjusted HR 1.14, 95% CI 0.81 - 1.62). Women had lower crude mortality rate than men in the first 10 years (20.8% vs. 27.6%, p = .019). In women, cardiac disease was associated with increased mortality (adjusted HR 3.55, 95% CI 2.18 - 5.79), while in men, lipid lowering medication was protective (adjusted HR 0.61, 95% CI 0.39 - 0.96). Within the first five years after surgery, SMR was increased for all patients (men 1.50, 95% CI 1.21 - 1.86; women 2.41, 95% CI 1.74 - 3.35), as well as in patients < 80 years (SMR 1.46, 95% CI 1.23 - 1.73).

Conclusion: Symptomatic and asymptomatic carotid patients have similar long term mortality rates after CEA, but men had worse outcome than women. Sex, age, and time after surgery were shown to influence SMR. These results highlight the need for targeted secondary prevention, to alter the long term adverse effects in CEA patients.