Abstract 266: Effects Of Carotid Body Tumor Resection On Blood Pressure
Introduction: Removal of carotid body (CB) improves rodent models of HTN and HF, presumably via withdrawal of chemoreflex-induced sympathetic activation. CB tumor (CBT) resection abolishes the chemoreflex in humans and is associated with opposing effects on sympathetic regulation by accompanying damage of the baroreflex. The net effect of CBT removal on BP in subjects with pre-existent HTN is unknown.
Methods: Retrospective analysis of 134 patients with uni- or bilateral CBT resection between 1990-2012. Twenty subjects met HTN entry criteria (BP≥140/90 mmHg or use of antihypertensive drugs) but two were excluded from analyses because of inadequate data. BP changes were assessed by a) acute ΔSBP: the change from the average SBP for the 3 months preceding surgery to the first reading after 30 days from the procedure, and b) chronic: the slope of the regression of SBP on time over the entire follow up, expressed as ΔSBP/year. BP changes were adjusted with covariate analyses. Covariates for acute ΔSBP were: the interval between pre and post BP readings and the change in therapy during this interval (assessed by a score of medications based on equipotency). Covariates for chronic ΔSBP were: total duration of follow-up, number of SBP readings and change in therapy during the entire period of study.
Results: Age and duration of HTN were 56±4 and 10±4 years, respectively. There was a significant relationship between acute ΔSBP and the chronic slopes (r=0.47, p<0.05) indicating that initial BP responses to CBT removal tend to be sustained. The univariate relationship showed that for every change of 0.4 mmHg in acute ΔSBP, there was a concomitant 1 mmHg/yr change in the chronic slope. Thirteen subjects (72%) had concordant reductions of ΔSBP and slope of any magnitude. In 6 subjects (33%), acute ΔSBP was ≥ -10 mmHg (corresponding to concomitant slopes ≥ 5.9 mmHg/yr).
Conclusions: This is the first study to show that CBT removal is associated with a sustained reduction of BP in a subset of patients with comorbid HTN. Also, concomitant baroreceptor damage by CBT removal most likely leads to underestimation of the depressor effect of chemoreflex disruption. Development of a targeted removal of CB chemoreflex may conceivably have a role in the therapy of human hypertension.
Author Disclosures: M. Fudim: F. Ownership Interest (includes any stock, stock option, partnership, membership or other equity position in an entity regardless of the form of the entity, or any option or right to acquire such position, and any rights in any patent or other intellectu; Modest; Stock in Cibiem Inc.. K.L. Groom: None. C.L. Laffer: None. J.L. Netterville: None. D. Robertson: None. F. Elijovich: None.
- © 2014 by American Heart Association, Inc.