Abstract: FR-PO846

Use of Beta-Blockers Associated with Lower Orthostatic Response in Dialysis Patients

Session Information

Category: Dialysis

  • 606 Dialysis: Epidemiology, Outcomes, Clinical Trials - Cardiovascular

Author

  • Laham, Gustavo, CEMIC, Ciudad de Buenos Aires, Buenos Aires, Argentina
Background

Beta Blockers (BB) are widely used in dialysis patients (pts). However, the evidence supporting their utility in improving cardiovascular (CV) outcomes in this population is conflicting.

Methods

Within a CV evaluation program for pts with ESRD in our Hospital. We evaluated 102 pts attended the interdialysis day. BP and hemodynamics was determined with impedance cardiography in supine position and after the third minute of standing. Following variables: SBP, DBP, heart rate (HR), stroke volume (SV), systemic vascular resistance index (SVRI) and thoracic fluid content (TFC). At the same time, the variability of the frequency was evaluated during 3 minutes at rest and in standing position. Patients were classified into 2 groups according to the presence of Hypotension (HYPOT) or not (EST). Orthostatic hypotension was defined as a drop of 20mmHg or more of SBP and/or 10mmHg or more of DBP when standing. Hemodynamic variables were analyzed : 1-baseline conditions and 2-differences (delta standing-lying) between the two groups (t-test and Mann-Whitney U test). Independent predictors of orthostatic hypotension were determined adjusting for age, sex, BP, anthropometric variables, time on dialysis and medication through a logistic regression.

Results

We included 81 patients: age: 59,8 ± 14 years, female 55,5%: SBP: 137,7± 27,2 mmHg, DBP: 83,5 ± 19,7 mmHg. Twenty nine pts (35,8%) had orthostatic hypotension. No significant differences were found in age, sex, BMI, time on dialysis, DM and CV events between both groups. 86.21% of the pts in the HYPO group received BB and 28.8 of the pts in the EST group with a significant difference (p<0, 0004). At rest position there were no hemodynamic or autonomic differences between both groups, but in Standing position, HYPO group, showed delta of SVRI (p < 0.037) lower, as well as lower delta DBP, delta Median Blood Pressure and delta SBP (p< 0,0001) compared to de EST group. There were no significant differences in the delta TFC as well as between autonomic variables. In logistic regression the use of BB was an independent variable for orthostatic hypotension.

Conclusion

In this group of dialysis pts the use of BB was a determining factor to attenuate or nullify the compensatory increase of the vascular resistance against the bipedestation. Therefore BB could collaborate with the development of hypotension when standing independently of the autonomic response.