ASN 2010: Should JNC 7 Guidelines Be Used in Dialysis Patients?

Uncertainty concerning guidance benchmarks for monitoring blood pressure in chronic and end-stage renal disease prompted the organizers of Renal Week 2010, the 43rd Annual Meeting and Scientific Exposition of the American Society of Nephrology, to schedule a series of half-hour presentations dedicated to a vetting of the issue.

As the final speaker during a Sunday session titled “Controlling Blood Pressure in Dialysis Patients: Necessary or Overrated?,” George Bakris, MD, director of the Hypertensive Diseases Unit at the University of Chicago Pritzker School of Medicine, used plain language to clear the air regarding a lingering state of confusion and disagreement between nephrologists over published blood pressure guidance. “Should you use JNC guidelines in dialysis patients?” he asked his audience rhetorically. “I would put it very simply to you: Hell no. Because there’s no data that we used in dialysis patients to derive those (JNC) data. So that’s off the table.”

Bakris was referring to his participation on the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure that formulated diagnostic blood pressure standards for different indications. He was also referring to “potshots” that earlier speakers had taken at these guidelines with regard to their applicability for chronic kidney disease (CKD) patients.

Those points are essentially moot, Bakris rejoined, because the JNC, as well as a separate committee on which he served that was tasked with deciphering similar guidelines, did not have CKD patients in mind when the recommendations were formulated. This, he explained, was due to a lack of good blood pressure data for the CKD patient population. “There is no way that I or anybody on those committees would say that the data we put together in either one of those things is applicable to dialysis patients, period,” he said emphatically.

Bakris reminded those in attendance that the sheer clinical variability of disease states and kidney disease etiologies makes it problematic for any professional organizations that deign to formulate blanket standards for blood pressure monitoring and control. He said that “It’s very difficult to generalize with dialysis patients because they are extremely heterogeneous. Factors which make them heterogeneous include the etiology of renal failure. Number two: vascular calcifications. The stiffer your vessels, the less likely you are to achieve blood pressure control. Then there’s dietary compliance…”

Bakris is also convinced that the nephrology community does not make very good use of some of the therapeutic tools that are available. “There is a tremendous under-use of anti-hypertensive medicines specifically focused on the heart,” he said, citing beta blockers as an example. Bakris also noted that research he published in a 2004 paper observed that beta blockers were being used in just 20% of dialysis patients.

He had similar advice for what he views as the clinical underplay of ACE inhibitors, saying that “They don’t just save kidneys; they’re a vascular-focused agent that saves the heart as well. So when the kidneys are dead, then focus on the heart. If you look at antihypertensive medications in the meta-analysis on dialysis patients, I don’t think there’s any question that there’s a clear benefit.”

Bakris ended his talk with the following general conclusions:

• No clear guidelines exist for the proper points at which to measure blood pressure in hemodialysis patients.
• Volume control is a critical part of blood pressure management, although the quality of dialysis administered may also influence blood pressure.
• Dysregulation of neural regulatory mechanisms contributes to large fluctuations in blood pressure, and these are improved either by transplantation or more prolonged, better quality dialysis.