Early Systolic Blood Pressure Changes in Incident Hemodialysis Patients Are Associated with Mortality in the First Year (original) (raw)
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The Epidemiology of Systolic Blood Pressure and Death Risk in Hemodialysis Patients
American Journal of Kidney Diseases, 2006
Background: This study compares the associations of predialysis systolic blood pressure (SBP) with mortality risk in both incident and prevalent hemodialysis (HD) cohorts by using both conventional and time-varying Cox analyses, thus addressing limitations of prior studies. Methods: A total of 56,338 incident patients starting HD therapy during 1997 to 2001 and 69,590 prevalent HD patients on January 1, 2002, were grouped into the following categories: (1) SBP less than 120 mm Hg, (2) 120 < SBP < 140 mm Hg, (3) 140 < SBP < 160 mm Hg, (4) 160 < SBP < 180 mm Hg, (5) 180 < SBP < 200 mm Hg, and (6) SBP of 200 mm Hg or greater. Conventional and time-varying models evaluated 1-year and 3-year (incident patients only) survival. Results: Nine percent and 26.0% of incident patients and 5.7% and 20.1% of prevalent patients were in categories 1 and 2, respectively. Their associated 1-year hazard ratios (HRs) were 2.63 to 3.68 and 1.57 to 1.68 compared with category 4, the reference group. HRs for categories 3, 5, and 6 were not different from category 4. Time-varying models magnified category 1 and 2 HRs to 5.54 to 7.42 and 1.92 to 2.21, such that 25% to 35% of patients in the target SBP range (<140 mm Hg) had the greatest risk. A "reversed J-shaped" risk profile emerged in the time-varying models, with very high SBP (category 6) associated with HRs of 1.52 to 1.55, but only 1% of patients were in category 6. Three-year outcomes were similar. Conclusion: Epidemiological characteristics of predialysis SBP consistently differ from those in the general population despite different analytic perspectives. The data suggest a need for greater investigative, diagnostic, and therapeutic focus on HD patients with normal and prehypertensive blood pressure ranges. Am J Kidney Dis 48:606-615.
Changing Relationship of Blood Pressure with Mortality over Time among Hemodialysis Patients
Journal of the American Society of Nephrology, 2006
High BP is a major risk factor for atherosclerotic cardiovascular disease mortality in the general population. Surprising, studies that have been conducted among hemodialysis (HD) patients have yielded conflicting data on the relationship between BP and mortality. This study explores two hypotheses among HD patients: (1) The relationship between BP and mortality changes over time, and (2) mild to moderate hypertension is well tolerated. Incident HD patients who were treated at Dialysis Clinic Inc. facilities between 1993 and 2003 were studied. Primary end points were atherosclerotic cardiovascular disease and all-cause mortality. The relationship between BP and mortality was analyzed in two sets of Cox proportional hazards models. Model-B explored the relationship between baseline BP and mortality in sequential time periods. Model-TV assessed the relationship between BP, treated as time-varying, and mortality. The study sample (n ؍ 16,959) was similar in characteristics to the United States Renal Data Systems population, although black patients were slightly overrepresented. Model-B demonstrated that the relationship between baseline BP and mortality changes over time. Low systolic BP (<120 mmHg) was associated with increased mortality in years 1 and 2. High systolic BP (>150 mmHg) was associated with increased mortality among patients who survived >3 yr. Low pulse pressure was associated with increased mortality. Model-TV demonstrated that mild to moderate systolic hypertension may be relatively well tolerated. In conclusion, the relationship between baseline BP and mortality changes over time. Mild to moderate systolic hypertension was associated with only modest increases in mortality.
Kidney International, 2012
KDOQI practice guidelines recommend predialysis blood pressure o140/90 mm Hg; however, most prior studies had found elevated mortality with low, not high, systolic blood pressure. This is possibly due to unmeasured confounders affecting systolic blood pressure and mortality. To lessen this bias, we analyzed 24,525 patients by Cox regression models adjusted for patient and facility characteristics. Compared with predialysis systolic blood pressure of 130-159 mm Hg, mortality was 13% higher in facilities with 20% more patients at systolic blood pressure of 110-129 mm Hg and 16% higher in facilities with 20% more patients at systolic blood pressure of X160 mm Hg. For patient-level systolic blood pressure, mortality was elevated at low (o130 mm Hg), not high (X180 mm Hg), systolic blood pressure. For predialysis diastolic blood pressure, mortality was lowest at 60-99 mm Hg, a wide range implying less chance to improve outcomes. Higher mortality at systolic blood pressure of o130 mm Hg is consistent with prior studies and may be due to excessive blood pressure lowering during dialysis. The lowest risk facility systolic blood pressure of 130-159 mm Hg indicates this range may be optimal, but may have been influenced by unmeasured facility practices. While additional study is needed, our findings contrast with KDOQI blood pressure targets, and provide guidance on optimal blood pressure range in the absence of definitive clinical trial data.
Multiphasic effects of blood pressure on survival in hemodialysis patients
Kidney International, 2016
Dialysis patients exhibit an inverse, L-or U-shaped association between blood pressure and mortality risk, in contrast to the linear association in the general population. We prospectively studied 9333 hemodialysis patients in France, aiming to analyze associations between predialysis systolic, diastolic, and pulse pressure with all-cause mortality, cardiovascular mortality, and nonfatal cardiovascular endpoints for a median follow-up of 548 days. Blood pressure components were tested against outcomes in time-varying covariate linear and fractional polynomial Cox models. Changes throughout follow-up were analyzed with a joint model including both the timevarying covariate of sequential blood pressure and its slope over time. A U-shaped association of systolic blood pressure was found with all-cause mortality and of both systolic and diastolic blood pressure with cardiovascular mortality. There was an L-shaped association of diastolic blood pressure with all-cause mortality. The lowest hazard ratio of all-cause mortality was observed for a systolic blood pressure of 165 mm Hg, and of cardiovascular mortality for systolic/diastolic pressures of 157/90 mm Hg, substantially higher than currently recommended values for the general population. The 95% lower confidence interval was approximately 135/70 mm Hg. We found no significant correlation for either systolic, diastolic, or pulse pressure with myocardial infarction or nontraumatic amputations, but there were significant positive associations between systolic and pulse pressure with stroke (per 10-mm Hg increase: hazard ratios 1.15, 95% confidence interval 1.07 and 1.23; and 1.20, 1.11 and 1.31, respectively). Thus, whereas high pre-dialysis blood pressure is associated with stroke risk, low pre-dialysis blood pressure may be both harmful and a proxy for comorbid conditions leading to premature death.
Kidney International, 2013
It is not clear to what extent changes in blood pressure (BP) during hemodialysis affect or predict survival. Studying comparative outcomes of BP changes during hemodialysis can have major clinical implications including the impact on management strategies in hemodialysis patients. Here we undertook a retrospective cohort study of 113,255 hemodialysis patients over a 5 year period to evaluate an association between change in BP during hemodialysis and mortality. The change in BP was defined as post-minus pre-hemodialysis BP and mean of BP change values during the hemodialysis session was used as a mortality predictor. The patients averaged 61 years old and consisted of 45% women, 32% African-Americans and 58% diabetics. Over a median follow-up of 2.2 years, a total of 53,461 (47.2%) all-cause and 21,548 (25.7%) cardiovascular deaths occurred. In fully adjusted Cox regression model with restricted cubic splines, there was a U-shaped association between change systolic BP and all-cause mortality. Post-dialytic drops in systolic BP between −30 to 0 mmHg were associated with greater survival, but large decreases of systolic BP (more than −30 mmHg) and any increase in systolic BP (over 0 mmHg) were related to increased mortality. Peak survival was found at a change in systolic BP of −14 mmHg. The U-shaped association was also found for cardiovascular mortality. Thus, modest declines in BP after hemodialysis are associated with the greatest survival, whereas any rise or large decline in BP is associated with worsened survival. Park et al. Page 17 † Median (interquartile range) is used for dialysis duration and serum ferritin level. Dialysis duration was defined as the interval from the first dialysis to the entry into cohort. BP was defined as post-HD minus pre-HD BP. Ultrafiltration percentage (%) was calculated as (ultrafiltration per session [kg] / post-HD body weight [kg])*100. Body mass index was calculated using post-HD body weight and height. p-values were estimated by one-way ANOVA, Kruskal-Wallis and Chi square method as appropriate. Conversion factors for units: albumin and hemoglobin in g/dL to g/L, ×10; creatinine in mg/dL to mol/L, ×88.4; calcium in mg/dL to mmol/L, ×0.2495; phosphorus in mg/dL to mmol/L, ×0.3229. No conversion necessary for ferritin in ng/mL and g/L, and white blood cell count in 10 3
PLoS ONE, 2014
Systolic blood pressure variability is an independent risk factor for mortality and cardiovascular events. Standard measures of blood pressure predict outcome poorly in haemodialysis patients. We investigated whether systolic blood pressure variability was associated with mortality in incident haemodialysis patients. We performed a longitudinal observational study of patients commencing haemodialysis between 2005 and 2011 in East Anglia, UK, excluding patients with cardiovascular events within 6 months of starting haemodialysis. The main exposure was variability independent of the mean (VIM) of systolic blood pressure from short-gap, pre-dialysis blood pressure readings between 3 and 6 months after commencing haemodialysis, and the outcome was all-cause mortality. Of 203 patients, 37 (18.2%) patients died during a mean follow-up of 2.0 (SD 1.3) years. The age and sex-adjusted hazard ratio (HR) for mortality was 1.09 (95% confidence interval (CI) 1.02-1.17) for a one-unit increase of VIM. This was not altered by adjustment for diabetes, prior cardiovascular disease and mean systolic blood pressure (HR 1.09, 95% CI 1.02-1.16). Patients with VIM of systolic blood pressure above the median were 2.4 (95% CI 1.17-4.74) times more likely to die during follow-up than those below the median. Results were similar for all measures of blood pressure variability and further adjustment for type of dialysis access, use of antihypertensives and absolute or variability of fluid intake did not alter these findings. Diastolic blood pressure variability showed no association with all cause mortality. Our study shows that variability of systolic blood pressure is a strong and independent predictor of all-cause mortality in incident haemodialysis patients. Further research is needed to understand the mechanism as this may form a therapeutic target or focus for management.
Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, 2017
Intradialytic hypotension (IDH) occurs frequently in maintenance hemodialysis (HD) patients and may be associated with higher mortality. We hypothesize that nadir intradialytic systolic blood pressure (niSBP) is inversely related to death risk while iSBP change (Δ) and IDH frequency are incrementally associated with all-cause mortality. In a US-based cohort of 112 013 incident HD patients over a 5-year period (2007-11), using niSBP, ΔiSBP (pre-HD SBP minus niSBP) and IDH frequency (proportion of HD treatments with niSBP <90 mmHg) within the first 91 days of HD, we examined mortality-predictability at 1, 2 and 5 years using Cox models and restricted cubic splines adjusted for case-mix, comorbidities and laboratory covariates. We observed that niSBP of <90 and ≥140 mmHg had a 5-year mortality hazard ratio (HR) (95% confidence interval) of 1.57 (1.47-1.67) and 1.25 (1.18-1.33), respectively, compared with niSBP 110 to <120 mmHg. ΔiSBP of <15 and ≥50 compared with 21-30 mmHg...
Nephrology Dialysis Transplantation, 2001
Background. Age, diabetes and concomitant cardiovascular disease, recorded at the initiation of dialysis, allows the identi®cation of patients with a high probability of early mortality. When all of these factors are taken into account the mortality rate of dialysis patients is still 3.5 times higher than for the general population. Information on the factors that increase the mortality of patients lacking the major cardiovascular risk factors is important because these are likely to be correctable, especially if detected early. Methods. We investigated prospectively the relevance of blood pressure and other variables recorded at the initiation of dialysis treatment on the survival of a group of 103 relatively young adult haemodialysis patients (mean age 44.3 years "13 SD), with a low prevalence of comorbidity and a median follow-up period of 79 months. Data were analysed by the Cox proportional regression model and survival curves were constructed by the Kaplan±Meier method. Results. Forty-four patients died, 20 (46%) of whom as a result of cardiovascular causes. Multivariate analysis showed that mortality was associated with age (Ps0.0001), serum creatinine (Ps0.005, negative association), left ventricular (LV) mass (Ps0.003) and hypertension (Ps0.03). Mortality was increased by 7% for each additional year of age, by 0.7% for each 1 g increase in LV mass, and was reduced by 23% for each additional mgudl of serum creatinine. Hypertensive patients had a higher probability (3 2.2) of dying compared with normotensive patients. Conclusions. In addition to age and conditions of occult malnutrition, hypertension and LV hypertrophy, when present at the initiation of dialysis, play a major role in the mortality of low risk, relatively young dialysis patients. These potentially correctable factors should be actively sought and treated during the early stage of renal insuf®ciency to improve prognosis.
Kidney International, 2012
The association between changes in systolic and diastolic blood pressure, and the use of cardioprotective drugs on survival of incident hemodialysis patients, was examined in this retrospective cohort study. Pre-hemodialysis systolic and diastolic blood pressures were averaged over the first month of hemodialysis. Slopes, reflecting temporal changes, were computed by linear regression of systolic blood pressures and Cox regression was used for survival analyses. Patients were initially stratified into four cohorts (below 120, 120 to 150, 151 to 180, and above 180 mm Hg) and further subdivided into groups with stable (no more than a 1-mm Hg change per month), increasing (over 1-mm Hg per month), and decreasing (less than 1-mm Hg per month) slopes during the first year. Analyses were repeated for patients who were treated with cardioprotective drugs for 1 month or more in the second year. In 10,245 patients (59% prescribed cardioprotective drugs), both increases and decreases in all ranges of blood pressure were associated with worse outcomes, whereas stable blood pressure had a survival advantage at all levels of systolic and diastolic pressures. Use of cardioprotective drugs attenuated changes and improved survival. Validation and sensitivity analyses confirmed the primary findings. Therefore, previous temporal trends need to be considered in patient care, and the use of cardioprotective agents is associated with enhanced survival at all blood pressure levels.