PEARLS No. 200, October 2009, written by Brian R McAvoy

Clinical question

Compared to standard blood pressure (BP) targets (≤140- 160/90-100mmHg), how effective are lower BP targets (≤135/85mmHg) in reducing mortality and morbidity?  

Bottom line

Lower diastolic targets of ≤85mmHg achieved lower blood pressures but were not associated with a reduction in mortality or morbidity (stroke, heart attack, heart failure or kidney failure) when compared with the standard target of ≤90-100mmHg. The same conclusion is true if one limits the lower target group to trials with a diastolic target of ≤80mmHg. A sensitivity analysis in diabetic patients and in patients with chronic renal disease also did not show a reduction in any of the mortality and morbidity outcomes with lower targets as compared to standard targets.*
* As current guidelines recommend even lower targets for diabetes mellitus and chronic renal disease, the authors of the review are currently conducting systematic reviews in these groups of patients.  

Caveat

All of the identified trials assessed diastolic or mean blood pressure targets, and none of the trials compared different targets for systolic blood pressure. Therefore, at present we have no information regarding the benefits or harms of trying to achieve "lower systolic blood pressure targets" as compared with "standard systolic blood pressure targets". The main potential source of bias in this meta-analysis is inevitable because the intervention of trying to achieve a target blood pressure cannot be blinded. Another limitation of this meta-analysis is that one single trial provided most of the participants and outcome data. Selective reporting bias is also a significant source of bias in this metaanalysis, as in some trials certain outcomes were not reported.

Context

When treating elevated BP, doctors need to know what BP target they should try to achieve. The standard of clinical practice for some time has been ≤140-160/90-100mmHg. New guidelines are recommending BP targets lower than this standard.

Cochrane Systematic Review

Arguedas JA et al. Treatment blood pressure targets for hypertension. Cochrane Reviews 2009, Issue 3. Article No. CD004349. DOI: 10.1002/14651858.CD004349.pub2. This review contains 7 studies involving 22,089 participants.