Abstract P025: Arterial Stiffness is Unrelated to Number of Antihypertensive Medication Classes used to Normalize Blood Pressure with Control for Cardiovascular Risk Factors
Pulse wave velocity (PWV) has become the gold standard indirect measure of arterial stiffness. Previous research in our laboratory has indicated that polypharmacy (treatment with more than one antihypertensive medication class) is related to elevated levels of PWV. The present study examines this association using number of antihypertensive medication classes (1 to 4/5), a more precise measure of treatment regimen than polypharmacy. We hypothesize that any observed rise in PWV related to polypharmacy reflects severity of hypertension-related comorbidity, rather than the adverse influence of multiple medications.
Methods: Hypertensive participants (blood pressure [BP] ≥ 140/90 mmHg) (mean age = 67 years, 55% (205 of 373) female) came from the 6th and 7th waves of the community-based Maine-Syracuse Longitudinal Study (2001-2009). After the 5th wave, hypertensive participants in the present study (n = 373 after exclusions of acute stroke, dementia, and dialysis) were referred to their physicians for treatment-as-usual to normalize BP. By wave 6, 4-5 years after the referral, 52% (194 of 373) of hypertensives were normalized, and by wave 7, the percentage dropped to 44% (164 of 373). We related number of antihypertensive medication classes utilized for each individual to PWV using cross-sectional analyses at wave 7. Medication change between waves 6 and 7 was then used to predict wave 7 PWV.
Three sets of covariate controls were employed for each analysis: 1. basic (age + sex + education + ethnicity + heart rate); 2. PWV-relevant (basic + mean arterial pressure + height + weight); 3. cardiovascular disease (CVD) risk factor (basic + PWV-relevant + CVD prevalence + diabetes mellitus + HDL + waist circumference + number of cigarettes per week).
Results: In cross-sectional analyses controlling for basic and PWV-relevant covariates, there was a significant linear increase in PWV across rising number of antihypertensive medication classes. This relationship was only seen in subjects for whom BP was not controlled and was replicated with adjustment for number of other medications in the treatment regimen. Findings were not replicated when longitudinal analyses utilizing medication change were performed. It is notable that the largest increase in CVD prevalence was seen between persons taking 3 to 4/5 antihypertensive medication classes, further indicating the importance of severity of hypertension-related comorbidity when predicting PWV.
Conclusions: The elevation of PWV levels in persons treated with multiple antihypertensive medication classes reflects the fact that PWV is higher in persons most in need of polypharmacy, and is not a consequence of combining classes of medication to normalize BP. Higher PWV in those on more classes of antihypertensive medications is only seen in cross-sectional analyses and when complications of hypertension and other CVD risk factors are not taken into account.
Author Disclosures: R.V. Torres: None. M.F. Elias: None. K.J. Sullivan: None. G.A. Dore: None. M.A. Robbins: None.
- © 2015 by American Heart Association, Inc.