Five-year follow-up of patients after thromboendarterectomy of the internal carotid artery - Relevance of baroreceptor sensitivity

Background and Purpose In patients after myocardial infarction, baroreceptor sensitivity has been identified as a factor of prognostic relevance. This study was designed to assess the effects of an increased baroreceptor sensitivity in patients after surgery in the area of the internal carotid artery with respect to blood pressure variability, therapeutic interventions, and vascular events during a 5-year follow-up. Methods Receptor sensitivity before and immediately after carotid surgery was measured in 84 patients. Blood pressure variability, carotid artery status, and echocardiographic findings were assessed before and after surgery and at the end of follow-up. Vascular events as well as changes in blood pressure therapy during the follow-up period were evaluated. Results Significant negative correlations between an increase of baroreceptor sensitivity after surgery and the range of systolic (r=-.47; P<.001) and diastolic (r=-.33; P<.01)blood pressure were found for the immediate postoperative period. For the range of systolic blood pressure, this relation persisted (4.3 to 7 years after surgery) at the end of the observation period (r=-.38; P<.001). An inverse relation to the increase in baroreceptor function was also found for the average annual number of therapeutic interventions during follow-up (r=-.38; P<.001). Furthermore, the subgroup of patients without a postoperative increase of receptor sensitivity was characterized by a significantly higher risk of major vascular events (log-rank test, P<.018). Conclusions Because an improvement of receptor sensitivity after carotid surgery is related to a long-lasting reduction of blood pressure levels and variability, baroreceptor function may be considered an indirect indicator for the later postoperative course.