Implementation and efficacy of selective sonographic screening for carotid disease before cardiac surgery.

Background: Preoperative carotid sonography with consecutive preventive strategies might reduce stroke risk during cardiac surgery. Since routine sonography in all patients may be unfeasible, an approach to examine preselected patients was investigated.

Methods: A prognostic model predicting carotid disease was developed using the clinical data of 1,768 routinely examined patients. It recommended 1,018 of 4,814 patients of a following collective for selective sonography. Patients recommended for preoperative sonography were compared to those selected in clinical practice.

Results: Besides the evaluated predictor variables, a history of syncope/cardiogenic shock and of pulmonary disease was associated with patient selection for sonography in clinical practice, even though both variables were not associated with severe carotid disease. In patients who underwent sonography, although this was not recommended by the prognostic model, severe carotid disease was estimated lower than what was actually detected, suggesting a change in relative relevance of predicting variables along with the change in frequencies of patients' cardiovascular characteristics.

Conclusion: Prognostic models for selective screening before cardiac surgery may require reevaluation over time, especially when baseline characteristics used for prediction have changed. Criteria used in clinical practice to select patients for screening may differ from those recommended by investigational studies.