Long-term visit-to-visit office blood pressure variability increases the risk of adverse cardiovascular outcomes in patients with chronic kidney disease

Individual 6-year systolic blood pressure change and impact on cardiovascular mortality in a French general population

Impact of blood pressure (BP) visit-to-visit variability remains controversial for untreated hypertensives and for normotensive subjects. Association between 6-year systolic BP change and all-cause and cardiovascular (CVD) mortality was studied in general primary care population including untreated hypertensive and normotensive subjects. Normotensive individuals and untreated high BP patients (40,926 and 14,283, respectively) had two check-ups (interval: 5.8±2.2 years) at the IPC center (Paris). Follow-up was 6.1±3.2 years: 1131 people died, 114 from CVD causes. Systolic BP (SBP) change was assessed by tertiles of absolute differences between V1 and V2, and the relationship with mortality was analysed with multivariate Cox models (hazard ratio (HR), 95% confidence interval (CI)) including V1 or V2 parameters notably SBP. Adjusting for V1 variables, mortality was associated with SBP change, for the entire population (all-cause: HR=1.15 (95%: 1.01-1.30) and CVD: HR=1.95 (95%: 1.25-3.05)) and in hypertensive individuals: (HR=1.31 (95%: 1.08-1.59) and HR=2.51 (95%: 1.34-4.72), respectively). Adjustments for V2 variables gave similar results. For those who were normotensive at V1, the associations were not significant. In this primary care population, individual long-term visit-to-visit change of BP is an independent predictor of all-cause mortality in hypertensive individuals but not in those with normal BP.

Medication adherence and visit-to-visit variability of systolic blood pressure in African Americans with chronic kidney disease in the AASK trial

Lower adherence to antihypertensive medications may increase visit-to-visit variability of blood pressure (VVV of BP), a risk factor for cardiovascular events and death. We used data from the African American Study of Kidney Disease and Hypertension (AASK) trial to examine whether lower medication adherence is associated with higher systolic VVV of BP in African Americans with hypertensive chronic kidney disease (CKD). Determinants of VVV of BP were also explored. AASK participants (n=988) were categorized by self-report or pill count as having perfect (100%), moderately high (75-99%), moderately low (50-74%) or low (<50%) proportion of study visits with high medication adherence over a 1-year follow-up period. We used multinomial logistic regression to examine determinants of medication adherence, and multivariable-adjusted linear regression to examine the association between medication adherence and systolic VVV of BP, defined as the coefficient of variation or the average real variability (ARV). Participants with lower self-reported adherence were generally younger and had a higher prevalence of comorbid conditions. Compared with perfect adherence, moderately high, moderately low and low adherence was associated with 0.65% (±0.31%), 0.99% (±0.31%) and 1.29% (±0.32%) higher systolic VVV of BP (defined as the coefficient of variation) in fully adjusted models. Results were qualitatively similar when using ARV or when using pill counts as the measure of adherence. Lower medication adherence is associated with higher systolic VVV of BP in African Americans with hypertensive CKD; efforts to improve medication adherence in this population may reduce systolic VVV of BP.

Prognostic significance of visit-to-visit systolic blood pressure variability: a meta-analysis of 77,299 patients

In recent clinical investigations, visit-to-visit systolic blood pressure (SBP) variability was proven as a predictor of cardiovascular events and all-cause mortality. However, inconsistent results exist in this association. A meta-analysis of 13 prospective studies was conducted to evaluate the prognostic value of visit-to-visit SBP variability by different parameters in 77,299 patients with a mean follow-up of 6.3 years. The pooled age- and mean SBP-adjusted hazard ratios (HRs) for all-cause mortality were 1.03 (95% confidence interval [CI], 1.02-1.04; P<.001) per 1-mm Hg increase in SBP standard deviation (SD) and 1.04 (1.02-1.06, P<.001) per 1% in SBP coefficient of variation, and the corresponding values of cardiovascular mortality were 1.10 (1.02-1.17, P<.001) and 1.01 (0.99-1.03, P=.32), respectively. Moreover, a 1-mm Hg increase in SD was significantly associated with stroke, with an HR of 1.02 (1.01-1.03, P<.001). Visit-to-visit SBP variability, independent of age and mean SBP, is a predictor of cardiovascular and all-cause mortality and stroke.

Visit-to-visit variability of blood pressure and cardiovascular disease and all-cause mortality: a systematic review and meta-analysis

Visit-to-visit variability of blood pressure (BP) has been associated with cardiovascular disease (CVD) and mortality in some but not all studies. We conducted a systematic review and meta-analysis to examine the association between visit-to-visit variability of BP and CVD and all-cause mortality. Medical databases were searched through June 4, 2014, for studies meeting the following eligibility criteria: adult participants; BP measurements at ≥3 visits; follow-up for CVD, coronary heart disease, stroke, or mortality outcomes; events confirmed via database, death certificate, or event ascertainment committee; and adjustment for confounders. Data were extracted by 2 reviewers and pooled using a random-effects model. Overall, 8870 abstracts were identified of which 37 studies, representing 41 separate cohorts, met inclusion criteria. Across studies, visit-to-visit variability of systolic BP and diastolic BP showed significant associations with outcomes in 181 of 312 (58.0%) and 61 of 188 (32.4%) analyses, respectively. Few studies provided sufficient data for pooling risk estimates. For each 5 mm Hg higher SD of systolic BP, the pooled hazard ratio for stroke across 7 cohorts was 1.17 (95% confidence interval [CI], 1.07-1.28), for coronary heart disease across 4 cohorts was 1.27 (95% CI, 1.07-1.51), for CVD across 5 cohorts was 1.12 (95% CI, 0.98-1.28), for CVD mortality across 5 cohorts was 1.22 (95% CI, 1.09-1.35), and for all-cause mortality across 4 cohorts was 1.20 (95% CI, 1.05-1.36). In summary, modest associations between visit-to-visit variability of BP and CVD and all-cause mortality are present in published studies. However, these findings are limited by the small amount of data available for meta-analysis.

Visit-to-visit variability of blood pressure and renal function decline in patients with diabetic chronic kidney disease

The authors previously reported that the visit-to-visit variability of blood pressure is correlated with renal function decline in nondiabetic chronic kidney disease. Little is known about the association between visit-to-visit variability and renal function decline in patients with diabetic chronic kidney disease. The authors retrospectively studied 69 patients with diabetic chronic kidney disease stage 3a, 3b, or 4. The standard deviation and coefficient of variation of blood pressure in 12 consecutive visits were defined as visit-to-visit variability of blood pressure. The median observation period was 32 months. In univariate correlation, the standard deviation and coefficient of variation of blood pressure were not significantly associated with the slope of estimated glomerular filtration rate. There was no significant association between the visit-to-visit variability of blood pressure and renal function decline in patients with diabetic chronic kidney disease, in contrast with our previous study of nondiabetic patients with chronic kidney disease.

High-NaCl diet impairs dynamic renal blood flow autoregulation in rats with adenine-induced chronic renal failure

This study examined the effects of 2 wk of high-NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without adenine (controls). After 10 wk, rats were randomized to either remain on the same diet (0.6% NaCl) or to be switched to high 4% NaCl chow. Two weeks after randomization, renal clearance experiments were performed under isoflurane anesthesia and dynamic RBFA, baroreflex sensitivity (BRS), systolic arterial pressure variability (SAPV), and heart rate variability were assessed by spectral analytical techniques. Rats with ACRF showed marked reductions in glomerular filtration rate and renal blood flow (RBF), whereas mean arterial pressure and SAPV were significantly elevated. In addition, spontaneous BRS was reduced by ∼50% in ACRF animals. High-NaCl diet significantly increased transfer function fractional gain values between arterial pressure and RBF in the frequency range of the myogenic response (0.06–0.09 Hz) only in ACRF animals (0.3 ± 4.0 vs. −4.4 ± 3.8 dB; P < 0.05). Similarly, a high-NaCl diet significantly increased SAPV in the low-frequency range only in ACRF animals. To conclude, a 2-wk period of a high-NaCl diet in ACRF rats significantly impaired dynamic RBFA in the frequency range of the myogenic response and increased SAPV in the low-frequency range. These abnormalities may increase the susceptibility to hypertensive end-organ injury and progressive renal failure by facilitating pressure transmission to the microvasculature.

What should be the goal blood pressure in nondiabetic chronic kidney disease?

PURPOSE OF REVIEW

To summarize the available evidence on whether a lower blood pressure (BP) treatment target can ameliorate the progression of nondiabetic chronic kidney disease (CKD), and prevent cardiovascular events in CKD patients.

RECENT FINDINGS

The three prospective, randomized controlled trials which addressed the question of progression of CKD suggest that a lower BP treatment goal (<130/80 mmHg) may lead to better preservation of renal function, but only in those patients with proteinuria of more than 300 mg/day. However, the evidence is not conclusive. We are not aware of adequately powered, randomized trials that have assessed the efficacy of lower target BP levels for the prevention of cardiovascular events specifically in nondiabetic CKD patients. The available circumstantial evidence (e.g., subgroup analyses of CKD patients in cardiovascular trials) fails to reveal a clear benefit of a lower BP goal.

SUMMARY

There is currently no convincing evidence to recommend a lower than standard BP treatment target of less than 140/90 mmHg for all patients with nondiabetic CKD. A lower treatment target of less than 130/80 mmHg may delay renal disease progression but only in patients with proteinuria.

Effect of erythropoiesis-stimulating agents on blood pressure in pre-dialysis patients

Introduction

Erythropoiesis-Stimulating Agents (ESA) are hypothesized to increase cardiovascular mortality in patients with chronic kidney disease. One of the proposed mechanisms is the elevation of blood pressure (BP) by ESA. Therefore, we aimed to determine whether the use of ESA was associated with antihypertensive treatment and higher BP.

Materials and Methods

In this cohort 502 incident pre-dialysis patients were included who started specialized pre-dialysis care in 25 clinics in the Netherlands. Data on medication including ESA use and dose, co-morbidities and BP were routinely collected every 6 months. Antihypertensive treatment and BP were compared for patients with and without ESA at baseline. Differences in antihypertensive medication and BP during pre-dialysis care were estimated with linear mixed models adjusted for age, sex, body mass index, cardiovascular disease, diabetes mellitus and estimated glomerular filtration rate.

Results

At baseline, 95.6% of patients with ESA were treated with antihypertensive medication and 73.1% of patients without ESA. No relevant difference in BP was found. During pre-dialysis care patients with ESA used 0.77 (95% CI 0.63;0.91) more classes of antihypertensive drugs. The adjusted difference in systolic blood pressure (SBP) was −0.3 (95% CI −2.7;2.0) mmHg and in diastolic blood pressure (DBP) was −1.0 (95% CI −2.1;0.3) mmHg for patients with ESA compared to patients without ESA. Adjusted SBP was 3.7 (95% CI −1.6;9.0) mmHg higher in patients with a high ESA dose compared to patients with a low ESA dose.

Conclusions

Our study confirms the hypertensive effect of ESA, since ESA treated patients received more antihypertensive agents. However, no relevant difference in BP was found between patients with and without ESA, thus the increase in BP seems to be controlled for by antihypertensive medication.