From short-term blood pressure variability to atherosclerosis: Relative roles of vascular stiffness and endothelial dysfunction.

Both arterial blood pressure (BP) average levels and short-term BP variability (BPV) relate to hypertension-mediated organ damage, in particular increased carotid artery intima-media thickness (IMT) and carotid-femoral pulse wave velocity (PWV). Endothelial dysfunction possibly mediates such damage. The authors aimed at further investigating such role in hypertensive patients. In 189 recently diagnosed, untreated hypertensive patients the authors evaluated, in a cross-sectional design, the relationships of BP average levels and short-term systolic (S) BPV (standard deviation of awake SBP or of 24-hour-weighted SBP) with IMT and PWV, and how much these relationships are explained by endothelial function parameters-brachial artery flow-mediated dilation (FMD) and digital reactive hyperemia index (RHI). Multivariable models assessed the strength of these relationships to derive a plausible pathogenetic sequence. Both average SBP values and our measures of SBPV were significantly related to IMT (24-hour mean SBP: r = .156, P = .034; 24-hour-weighted SBPV: r = .157, P = .033) and to PWV (24-hour mean SBP: r = .179, P = .015; 24-hour-weighted SBPV: r = .175; P = .018), but only poorly related to FMD or RHI (P > .05 for all). At univariable regression analysis, FMD and RHI were both related to IMT, (P < .001), but not to PWV. When FMD and RHI were added to average SBP and SBPV parameters in a multivariable model, both significantly (P < .005) contributed to predict IMT, but not PWV. Thus, endothelial dysfunction relates to IMT independently of BP parameters, but appears to play a minor role in the association between BP variability-related variables and arterial stiffening.

Increased short-term blood pressure variability is associated with early left ventricular systolic dysfunction in newly diagnosed untreated hypertensive patients.

BACKGROUND AND AIM: Twenty-four-hour blood pressure (BP) variability, by ambulatory BP monitoring (ABPM), has been related to left ventricular hypertrophy, independent of mean BP values. We tested the hypothesis that short-term BP variability (BPV) is also related to subclinical left ventricular systolic dysfunction. METHODS: We assessed 24-h SBP and DBP variabilities, quantified as standard deviation (SD) of daytime (awake) BP values and as weighted SD of 24-h BP (24-h-weighted BPV), in 309 recently (<6 months) diagnosed, prospectively recruited, and untreated hypertensive patients. Patients were included only if with normal (≥55%) left ventricular ejection fraction (LVEF). Left ventricular systolic function was assessed by echocardiography measuring midwall fractional shortening (MFS), circumferential end-systolic stress (cESS), MFS/cESS, peak systolic wall stress, left ventricular fractional shortening (LVFS), and LVEF. RESULTS: At multivariate analysis, awake and 24-h-weighted SBP variabilities (directly, P = 0.038 and P = 0.002, respectively) as well as relative wall thickness (RWT) (inversely, P = 0.001) were significantly related to cESS. Awake and 24-h SBP average values (inversely, P = 0.011 and P = 0.002, respectively), awake and 24-h-weighted SBP variabilities (inversely, P = 0.017 and P = 0.024, respectively), and RWT (directly, P = 0.001) were all significantly related to MFS/cESS. Finally, awake and 24-h average SBP (directly, P = 0.01 for both), awake and 24-h-weighted SBP variability (directly, P = 0.001 and P = 0.032, respectively), and RWT (inversely, P = 0.001) were all significantly and independently related to peak systolic wall stress. CONCLUSION: In newly diagnosed never-treated hypertensive patients, in the absence of LVEF changes and independent of left ventricular mass index, higher awake, or 24-h-weighted short-term SBP variabilities are associated with early depressed left ventricular systolic function.