It is uncertain which blood pressure values (pre- or post-haemodialysis) best represent the average daily blood pressure in haemodialysis patients. The purpose of this study was to verify the power of peridialysis blood pressure to predict interdialytic blood pressure, and to ascertain the influence of blood pressure fluctuations during dialysis on this predictive ability.
We performed ambulatory blood pressure monitoring during the interdialytic period on 60 stable haemodialysis patients (mean age 53±16 years, 33 male) between two mid-week haemodialysis sessions. Pre- and post-haemodialysis blood pressures were 154/82 and 142/77 mmHg, respectively, and 44-h interdialytic blood pressure was 136/77 mmHg. Overall, post-haemodialysis blood pressure values correlated with interdialytic ambulatory blood pressure marginally better than did pre-haemodialysis values (r=0.52 versus 0.61 for pre- and post-dialysis systolic pressure, respectively; r=0.67 versus 0.72 for pre- and post-dialysis diastolic pressure, respectively). The average of the pre- and post-haemodialysis values showed a slightly better correlation with interdialytic blood pressure (r=0.65 and 0.75 for systolic and diastolic pressure, respectively). When we stratified patients according to systolic blood pressure behaviour during dialysis, pre-dialysis blood pressure was the stronger predictor of interdialytic blood pressure in the quartile with greatest intradialytic blood pressure fall (r=0.67 versus 0.44 for pre- and post-dialysis systolic blood pressure, respectively), whereas post-dialysis values were substantially better in the group with a rise in systolic pressure during dialysis (r=0.26 versus 0.59 for pre- and post-dialysis systolic blood pressure, respectively).
These data demonstrate that peridialysis blood pressure values are of limited accuracy in predicting interdialytic blood pressure, post-dialysis values are minimally better predictors than pre-dialysis blood pressures, and the average of pre- and post-haemodialysis values is marginally better than both. In addition, blood pressure fluctuations during dialysis have a sizable impact on this predictive ability. Clinical decisions related to blood pressure management and research design in haemodialysis hypertension should take these factors into account.
aGAMEN – Grupo de Assistencia Medica e Nefrologica, Rio de Janeiro, Brazil
bDivision of Nephrology
cDivision of Informatics, State University of Rio de Janeiro, Brazil
dDivision of Hypertension and Clinical Pharmacology, University of Connecticut School of Medicine, Farmington, Connecticut
eSection of Nephrology, Yale University School of Medicine, New Haven, Connecticut and VA Connecticut – West Haven Campus, West Haven, Connecticut, USA
Parts of this manuscript were presented at the XXIX Meeting of the American Society of Nephrology (Philadelphia, PA, November 1998) and at the XIII Meeting of the American Society of Hypertension (New York, NY, May 2000).
Correspondence and requests for reprints to Aldo J. Peixoto, MD, Renal Section – 111F, 950 Campbell Ave., West Haven, CT 06510, USA.
Tel: +1 203 932 5711 ext. 2215; fax: +1 203 937 3455;
Received 19 September 2003 Revised 13 November 2003 Accepted 17 November 2003