NEW YORK (Reuters Health) – Current evidence is still inconclusive as to whether patients with chronic kidney disease (CKD) may benefit from aggressive blood pressure control, according to a new review.

The study, published in the Annals of Internal Medicine, did not find improved clinical outcomes – including incidences of kidney failure, cardiovascular events, and death – in patients managed with a BP target of <130/80 mmHg, rather than the normal target of <140/90 mmHg. The findings also suggested that more antihypertensive drugs are necessary in patients with a lower target, and that these patients may also need monitoring for symptoms of hypotension. The authors were funded by the National Kidney Foundation, and the findings will inform Kidney Disease Improving Global Outcomes (KDIGO) guidelines. “We don’t have compelling evidence that in this time frame (mean 2-4 years), there is a benefit from the lower targets,” study author Dr. Katrin Uhlig, from the Tufts Medical Center in Boston, told Reuters Health. “Even the follow-ups really haven’t been conclusive,” she said. Based on this, Dr. Uhlig continued, “we’re suggesting to revisit the recommended targets, as will be done in the guideline groups.” Although there is still controversy over the proper blood pressure targets for people with CKD, current guidelines recommend a target of 130/80 mmHg or below, given that these patients have a higher-than-average risk of kidney failure and cardiovascular disease. The current review included three trials and a total of 2,272 patients with CKD. Each trial compared the rate of adverse events in a low target BP group and a normal target BP group, with a combined mean follow-up of 2 to 4 years. The studies also included subgroups of patients with proteinuria, but all excluded patients with actively managed diabetes. Overall, trials that put patients on a lower target of 1000mg/day or a protein-to-creatinine ratio >0.22g/g. The third study, Ramipril’s Efficacy in Nephropathy-2 (REIN-2) trial, did not suggest a benefit for lower targets in participants with proteinuria.

Using a lower BP target may also have its risks, the authors said. They calculated that patients with a lower target required an average of 0.3 to 0.6 additional antihypertensive drugs each. In some of the trials these patients reported more cough symptoms and more incidences of feeling faint and were more likely to need their antihypertensive medications cut back because of hypotension symptoms.

“It may not be wrong to treat (these patients) this low, but … it’s not proven that pushing people more will improve their survival and prevent heart attacks and strokes and lower their risk of kidney failure,” Uhlig said. However, she added, “there is the consistent signal that there may be benefits, if for anybody, than for those with higher proteinuria (at) baseline.” Those patients, she said, seem to be the ones that progress most rapidly towards kidney failure.

Until there is more evidence on managing blood pressure in patients with CKD, particularly in those that also have diabetes and more elderly patients, doctors should manage cases on a patient-by-patient basis, the authors said.

“We suggest that practitioners use discretion in individuals with CKD with proteinuria and choose the blood pressure target based on individualized risk benefit assessment, and (each) patient’s tolerance and preferences,” they conclude. “Treatment to a lower target may require greater vigilance to monitor for and avoid possible symptoms and adverse events from hypotension.”

Annals of Internal Medicine, online March 14, 2011.