Hypervolemia rather than arterial calcification and extracoronary atherosclerosis is the main determinant of pulse pressure in hemodialysis patients

Association between pulse pressure and carotid plaques in old adults with uncontrolled hypertension: results from a community-based screening in Hangzhou, China

BACKGROUND

There is a broad pulse pressure (PP) and a high prevalence of carotid plaques in old adults. Previous studies have indicated that PP is strongly associated with carotid plaque formation. This study aimed to explore this association in old adults with uncontrolled hypertension.

METHODS

1371 hypertensive patients aged ≥ 60 years with uncontrolled hypertension were enrolled in a community-based screening in Hangzhou, China. Carotid plaques were assessed using ultrasonography. Logistic regression models were used to estimate the association between PP and carotid plaques by odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Carotid plaques were detected in 639 (46.6%) of subjects. Multiple plaques were found in 408 (63.8%) and soft plaques in 218 (34.1%). Elevated PP was associated with a high prevalence of carotid plaques. After adjusting for traditional risk factors, compared to patients within the lowest tertile of PP, those within the highest tertiles had an increased risk of carotid plaques (OR 2.061, CI 1.547-2.745). For each 1-SD increase, the risk increased by 40.1% (OR 1.401, CI 1.237-1.587). There was a nonlinear association between PP and carotid plaques (P nonlinearity = 0.039). The risk increased rapidly after the predicted PP level reached around 60 mmHg. The associations were stronger among participants with multiple and soft plaques.

CONCLUSIONS

Our findings suggested that PP was independently associated with carotid plaques in old adults with uncontrolled hypertension who have an increased risk of atherosclerosis.

Volume status and arterial blood pressures are associated with arterial stiffness in hemodialysis patients

BACKGROUND

Arterial stiffness is a strong predictor of mortality in hemodialysis patients. In this study, we aimed to investigate possible relations of arterial stiffness with volume status determined by bioimpedance analysis and aortic blood pressure parameters. Also, effects of a single hemodialysis session on these parameters were studied.

METHODS

A total of 75 hemodialysis patients (M/F: 43/32; mean age: 53 ± 17) were enrolled. Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure were measured by applanation tonometry before and after hemodialysis. Extracellular fluid and total body fluid volumes were determined by bioimpedance analysis.

RESULTS

Carotid-femoral pulse wave velocity (9.30 ± 3.30 vs 7.59 ± 2.66 m/s, p < 0.001), augmentation index (24.52 ± 9.42 vs 20.28 ± 10.19, p < 0.001), and aortic pulse pressure (38 ± 14 vs 29 ± 8 mmHg, p < 0.001) significantly decreased after hemodialysis. Pre-dialysis carotid-femoral pulse wave velocity was associated with age (r² = 0.15, p = 0.01), total cholesterol (r² = 0.06, p = 0.02), peripheral mean blood pressure (r² = 0.10, p = 0.005), aortic-mean blood pressure (r² = 0.06, p = 0.02), aortic pulse pressure (r² = 0.14, p = 0.001), and extracellular fluid/total body fluid (r² = 0.30, p < 0.0001). Pre-dialysis augmentation index was associated with total cholesterol (r² = 0.06, p = 0,02), aortic-mean blood pressure (r² = 0.16, p < 0.001), and aortic pulse pressure (r² = 0.22, p < 0.001). Δcarotid-femoral pulse wave velocity was associated with Δaortic-mean blood pressure (r² = 0.06, p = 0.02) and inversely correlated with baseline carotid-femoral pulse wave velocity (r² = 0.29, p < 0.001). Pre-dialysis Δaugmentation index was significantly associated with Δaortic-mean blood pressure (r² = 0.09, p = 0.009) and Δaortic pulse pressure (r² = 0.06, p = 0.03) and inversely associated with baseline augmentation index (r² = 0.14, p = 0.001). In multiple linear regression analysis (adjusted R² = 0.46, p < 0.001) to determine the factors predicting Log carotid-femoral pulse wave velocity, extracellular fluid/total body fluid and peripheral mean blood pressure significantly predicted Log carotid-femoral pulse wave velocity (p = 0.001 and p = 0.006, respectively).

CONCLUSION

Carotid-femoral pulse wave velocity, augmentation index, and aortic pulse pressure significantly decreased after hemodialysis. Arterial stiffness was associated with both peripheral and aortic blood pressure. Furthermore, reduction in arterial stiffness parameters was related to reduction in aortic blood pressure. Pre-dialysis carotid-femoral pulse wave velocity was associated with volume status determined by bioimpedance analysis. Volume control may improve not only the aortic blood pressure measurements but also arterial stiffness in hemodialysis patients.

Impact of residual urine volume decline on the survival of chronic hemodialysis patients in Kinshasa

Background

Despite the multiple benefits of maintaining residual urine volume (RUV) in hemodialysis (HD), there is limited data from Sub-Saharan Africa. The aim of this study was to assess the impact of RUV decline on the survival of HD patients.

Methods

In a retrospective cohort study, 250 consecutive chronic HD patients (mean age 52.5 years; 68.8% male, median HD duration 6 months) from two hospitals in the city of Kinshasa were studied, between January 2007 and July 2013. The primary outcome was lost RUV. Preserved or lost RUV was defined as decline RUV < 25 (median decline) or ≥ 25 ml/day/month, respectively. The second endpoint was survival (time-to death). Survival curves were built using the Kaplan-Meier methods. We used Log-rank test to compare survival curves. Predictors of mortality were assessed by Cox proportional hazards regression models.

Results

The cumulative incidence of patients with RUV decline was 52, 4%. The median (IQR) decline in RUV was 25 (20.8–33.3) ml/day/month in the population studied, 56.7 (43.3–116.7) in patients deceased versus 12.9 (8.3–16.7) in survivor patients (p < 0.001). Overall mortality was 78 per 1000 patient years (17 per 1000 in preserved vs 61 per 1000 lost RUV). Forty six patients (18.4%) died from withdrawal of HD due to financial constraints. The Median survival was 17 months in the whole group while, a significant difference was shown between lost (10 months, n = 119) vs preserved RUV group (30 months, n = 131; p = 0001). Multivariate Cox proportional hazards models showed that, decreased RUV (adjusted HR 5.35, 95% CI [2.73–10.51], p < 0.001), financial status (aHR 2.23, [1.11–4.46], p = 0.024), hypervolemia (a HR 2.00, [1.17–3.40], p = 0.011), lacking ACEI (aHR 2.48, [1.40–4.40], p = 0.002) or beta blocker use (aHR 4.04, [1.42–11.54], p = 0.009), central venous catheter (aHR 6.26, [1.71–22.95], p = 0.006), serum albumin (aHR 0.93, [0.89–0.96], p < 0.001) and hemoglobin (aHR 0.73, [0.63–0.84], p < 0.001) had emerged as the independent predictors of all-cause mortality.

Conclusion

More than half of HD patients in this cohort study experienced fast RUV decline which contributed substantially to increase mortality, highlighting the need for its prevention and management.

Changes in pulse pressure during hemodialysis treatment and survival in maintenance dialysis patients

BACKGROUND AND OBJECTIVES

Pulse pressure has been shown as a risk factor for mortality in patients on maintenance hemodialysis (MHD). However, the effect of change in pulse pressure during hemodialysis on survival in a large cohort of patients on MHD has not been sufficiently investigated.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This study examined the association between time-varying Δ pulse pressure (postdialysis minus predialysis pulse pressure) and mortality in a cohort of 98,577 patients on MHD (July 2001-June 2006) using Cox proportional hazard models with restricted cubic splines.

RESULTS

The average patient age was 62 years old; among the patients, 33% were black and 59% had diabetes. During 134,814 patient-years of at-risk time, 16,054 (16%) patients died, with 6827 (43%) of the deaths caused by cardiovascular causes. In the models including adjustment for either predialysis systolic BP or mean arterial BP, there was a U-shaped association between change in pulse pressure during hemodialysis and all-cause mortality. In the systolic BP plus case mix plus malnutrition-inflammation complex syndrome-adjusted model, large declines in pulse pressure (>-25 mmHg) and increases in pulse pressure >5 mmHg were associated with higher all-cause mortality (reference: ≥-5 to <5 mmHg): hazard ratios (95% confidence intervals [95% CIs]) for change pulse pressures of <-25, ≥-25 to <-15, ≥-15 to <-5, 5 to <15, 15 to <25, and ≥25 mmHg were 1.21 (95% CI, 1.14 to 1.29), 1.03 (95% CI, 0.97 to 1.10), 1.01 (95% CI, 0.96 to 1.06), 1.06 (95% CI, 1.01 to 1.11), 1.17 (95% CI, 1.11 to 1.24), and 1.15 (95% CI, 1.08 to 1.23), respectively. The U-shaped association was observed with cardiovascular death.

CONCLUSIONS

Modest reductions in pulse pressure after hemodialysis are associated with the greatest survival, whereas large declines or rises in pulse pressure are related to higher mortality. Trials determining how to modify pulse pressure response to improve survival in the hemodialysis population are indicated.