Implementation and Efficacy of Selective Sonographic Screening for Carotid Disease before Cardiac Surgery
published online 25 January 2010.
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.
1Department of Neurology, University of Magdeburg, Magdeburg, Germany
2Department of Anesthesia and Intensive Care, University of Magdeburg, Magdeburg, Germany
3Department of Thoracic and Cardiac Surgery, University of Magdeburg, Magdeburg, Germany
4Institute for Biometry and Medical Informatics, University of Magdeburg, Magdeburg, Germany
Correspondence to: Stefanie Schreiber, Department of Neurology, Otto-von-Guericke-Universität Magdeburg, Leipziger Str. 44, D-39120 Magdeburg, Germany.
ABSTRACT