Reduced baroreflex effectiveness index in hypertensive patients with chronic renal failure

Impaired arterial baroreflex function has been associated with an increased risk of ventricular arrhythmia and sudden death. This has also been suggested for patients with chronic renal failure (CRF) who are at high risk for cardiovascular morbidity. The aim of this study was to investigate the arterial baroreflex function in CRF patients with emphasis on analyzing the time during which the arterial baroreflex is active, the baroreflex effectiveness index (BEI).

Beat-to-beat blood pressure (measured with Portapres) and electrocardiography were continuously registered during 30 min rest in 216 hypertensive CRF patients on hemodialysis (n=95), continuous ambulatory peritoneal dialysis (n=59), or conservative treatment (n=59). The spontaneous sequence method was used to calculate BRS and BEI. Age-matched healthy subjects (n=43) were examined for comparison.

The BRS was reduced by 51% and the BEI by 49% in CRF patients compared with healthy subjects (P<.001 for both). In addition, CRF patients with diabetes showed further reductions compared with patients without diabetes (15% reduction of BRS and 44% of BEI, P<.01 for both). The treatment modality for renal failure had no effect on BRS or BEI. In a multivariate linear regression analysis, age, body mass index, and systolic blood pressure were independent predictors of BRS, whereas age and diabetes were independent predictors of BEI in patients with CRF.

We conclude that BEI, which is markedly reduced in hypertensive patients with CRF, may convey information on arterial baroreflex function that is complementary to BRS.