BP Guidelines May be Inappropriate for HD Patients
David Goodkin, MD
SEATTLE—Guidelines recommend that hemodialysis (HD) patients have predialysis BP levels below 140/90 mm Hg, but study findings suggest that such levels may increase their risk of death, according to David Goodkin, MD, an investigator with Arbor Research Collaborative for Health.
Dr. Goodkin presented the latest findings on BP and mortality from the Dialysis Outcomes and Practice Patterns Study (DOPPS) at the 30th Annual Dialysis Conference.
DOPPS is a prospective study of HD patients based on the collection of observational longitudinal data from representative, random samples of patients in 12 countries (Australia, Belgium, Canada, France, Germany, Japan, Italy, New Zealand, Spain, Sweden, the United States and the United Kingdom).
The mortality analyses in this study included 24,524 HD patients from 920 facilities. “There were no differences in mortality rates among hemodialysis patients with blood pressures of 140 to 160 compared with 130 to 140,” Dr. Goodkin said. “In hemodialysis patients, there have not been prospective studies to prove exactly what level we should be targeting. In the general population, the higher the blood pressure, the higher the odds ratio of death.”
The adjusted risk of mortality was 11% to 14% higher among patients with predialysis systolic BP of 110 to 130 compared with the reference patients between 130 and 140.
Prior epidemiological studies have also demonstrated worse outcomes with lower BP in HD patients. This has previously been attributed to comorbid conditions such as heart failure. The DOPPS data, however, were adjusted for patient demographics and 13 comorbid conditions (including heart failure, coronary artery disease, other cardiac disease, cerebrovascular disease, peripheral vascular disease, and diabetes), and still demonstrated higher mortality associated with systolic pressure below 130.
HD is hemodynamically stressful and BP may fall dramatically during dialysis, Dr. Goodkin said. “One theory is that if you have lower blood pressure coming into the dialysis unit, maybe you are at greater risk for precipitous falls during treatment, decreasing the blood flow to the heart muscle and leading to wall motion abnormalities, ischemia, scarring, heart failure and other problems. In the general population, lower blood pressures are often beneficial, but they may be dangerous for HD patients.” He noted that recent publications have demonstrated impaired myocardial blood flow and associated wall motion abnormalities during dialysis.
Facilities with higher percentages of patients with predialysis systolic BP values greater than 160, however, were associated with significantly higher risks of death.