Multiphasic effects of blood pressure on survival in hemodialysis patients

Abstract

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 time-varying 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.

Effectiveness of self‐management support in maintenance haemodialysis patients with hypertension: A pilot cluster randomized controlled trial

“…This finding is also clinically significant for dialysis patients because predialysis systolic hypertension remains a significant predictor of all‐cause death and cardiovascular survival . However, given the “U” curve association between BP and mortality in haemodialysis patients, greater reductions in SBP are not necessarily better . In our study, we selected the patients who had an average predialysis BP higher than 140/90 mmHg following the recommendations of the 2005 National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI) clinical practice guideline.…”

“…In our study, we selected the patients who had an average predialysis BP higher than 140/90 mmHg following the recommendations of the 2005 National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI) clinical practice guideline. However, recent data from the Dialysis Outcome and Practice Pattern Study (DOPPS) and Hannedouche et al have shown that the optimal predialysis SBP is in the range of 130–159 or 165 mmHg . But in any case, lowering BP is not the objective of hypertension management; the ultimate goal of BP control is to reduce hypertension related‐cardiovascular and cerebrovascular events.…”

“…28 However, given the "U" curve association between BP and mortality in haemodialysis patients, greater reductions in SBP are not necessarily better. 29,30 In our study, we selected the patients who had an average predialysis BP higher than 140/90 mmHg following the recommendations of the 2005 National Kidney Foundation Kidney Disease Outcomes Quality Initiative (KDOQI) clinical practice guideline. However, recent data from the Dialysis Outcome and Practice Pattern Study (DOPPS) and Hannedouche et al have shown that the optimal predialysis SBP is in the range of 130-159 or 165 mmHg.…”

“…However, recent data from the Dialysis Outcome and Practice Pattern Study (DOPPS) and Hannedouche et al have shown that the optimal predialysis SBP is in the range of 130-159 or 165 mmHg. 30,31 But in any case, lowering BP is not the objective of hypertension management; the ultimate goal of BP control is to reduce hypertension relatedcardiovascular and cerebrovascular events.…”

Blood pressure target for the dialysis patient

“…Prospectively collected predialysis systolic BP among 9333 hemodialysis patients in France using BP as a time-varying covariate also found a U-shaped association between systolic BP and mortality, with a systolic BP of 165 mm Hg associated with the lowest risk. 10 This seemingly paradoxical observation has been labeled "reverse epidemiology," in that the relationship between BP and outcomes is the reverse of what has been illustrated in the general population.…”