NEW YORK (Reuters Health) – In the general population of patients with elevated blood pressure, there is currently no evidence to support aiming for a blood pressure (BP) target lower than the standard 140 over 90 millimeters mercury (mm Hg), according to a Cochrane Review published July 8.

“We did not find any randomized trial comparing clinical events associated with different targets for systolic blood pressure,” lead author Dr. Jose A. Arguedas, from the University of Costa Rica, told Reuters Health. “In the seven trials comparing diastolic targets there was no difference, in terms of mortality of morbidity, when aiming for lower targets instead of the traditional target of less than 90 mm Hg.”

Over the last five years a trend toward lower BP targets (135 over 85 mm Hg) has been recommended by hypertension experts who set treatment guidelines, Dr. Arguedas’ team notes in their report. This trend is based on the assumption that “lower is better” when it comes to BP, heart attack and stroke, and that the benefits of lower blood pressure targets “outweigh the harms caused by the drugs,” the authors write.

This assumption, Dr. Arguedas and colleagues report, is not supported by their systematic review of 7 trials (22,089 patients) that analyzed the impact of a lower BP target of 135 over 85 mm Hg on mortality and morbidity, as compared with the standard BP target of 140 to 160 over 90 to 100 mm Hg.

While aggressive antihypertensive drug therapy did achieve modestly lower than standard BP, this was not associated with any reduction in death rates or serious morbidity, the investigators report.

Lower BP targets, versus standard BP targets, did not change total mortality, myocardial infarction, stroke, congestive heart failure, major cardiovascular events or end-stage renal disease.

With the available data, the researchers say they were unable to determine the “net health effect” of lower BP targets.

A sensitivity analysis in patients with diabetes or chronic renal disease also did not show a reduction in mortality or morbidity with lower BP targets compared to standard targets. However, “the evidence was slightly less robust for those subgroups of patients,” Dr. Arguedas noted in a prepared statement.

“We intend to carry out separate systematic reviews for those subgroups, especially because guidelines recommend even lower blood pressure targets for them,” he added.

Reference:
Cochrane Collaboration 2009.