Aortic Stiffness, Ambulatory Blood Pressure, and Predictors of Response to Antihypertensive Therapy in Hemodialysis

Abstract

Background: Arterial stiffness is associated with elevated blood pressure (BP), but it is unclear whether it also makes hypertension more resistant to treatment. Among hypertensive dialysis patients, this study investigated whether aortic stiffness determines ambulatory BP and predicts its improvement with therapy.

Study design: Post hoc analysis of the Hypertension in Hemodialysis Patients Treated With Atenolol or Lisinopril (HDPAL) trial.

Settings & participants: 179 hypertensive hemodialysis patients with echocardiographic left ventricular hypertrophy.

Predictor: Baseline aortic pulse wave velocity (PWV).

Outcome: Baseline and treatment-induced change in 44-hour ambulatory BP at 3, 6, and 12 months.

Measurements: Aortic PWV was assessed with an echocardiographic-Doppler technique (ACUSON Cypress, Siemens Medical), and 44-hour interdialytic ambulatory BP monitoring was performed with a Spacelabs 90207 monitor.

Results: Mean baseline aortic PWV was 7.6±2.7 (SD) m/s. Overall treatment-induced changes in ambulatory systolic BP (SBP) were -15.6±20.4, -18.9±22.5, and -20.0±19.7 mmHg at 3, 6, and 12 months. Changes in SBP were no different among tertiles of baseline PWV. Aortic PWV was associated directly with baseline ambulatory SBP and pulse pressure (PP) and inversely with diastolic BP (DBP). After adjustment for several cardiovascular risk factors, each 1-m/s higher PWV was associated with 1.34-mm Hg higher baseline SBP (β=1.34±0.46; P=0.004) and 1.02-mm Hg higher PP (β=1.02±0.33; P=0.002), whereas the association with DBP was no longer significant. Baseline PWV did not predict treatment-induced changes in SBP (Wald test, P=0.3) and DBP (Wald test, P=0.7), but was a predictor of an overall improvement in PP during follow-up (Wald test, P=0.03).

Limitations: Observational design; predominantly black patients were studied.

Conclusions: Because aortic PWV is not a predictor of treatment-induced change in ambulatory BP among hypertensive dialysis patients, it indicates that among these patients, hypertension can be controlled successfully regardless of aortic stiffness.

Keywords: Antihypertensive treatment; BP control; Hypertension in Hemodialysis Patients Treated with Atenolol or Lisinopril (HDPAL) trial; ambulatory blood pressure; aortic stiffness; arteriosclerosis; echocardiographic left ventricular hypertrophy; hemodialysis (HD); pulse wave velocity (PWV); renal replacement therapy (RRT).