Issue 33 / 27 August 2012

MORE intensive blood pressure lowering in high-risk patient groups should be included in clinical guidelines, according to the authors of a new meta-analysis that shows it provides greater vascular protection than standard BP goals. (1)

The meta-analysis of randomised controlled trials, which included more than 37 000 patients and more than 1900 major vascular events, was conducted by researchers from Australia, China, the US and Japan.

By comparing results for patients with standard and more aggressive BP-lowering targets, it found the benefits of intensive BP lowering to below current thresholds might achieve additional benefits in reducing the burden of cardiovascular morbidity for many patients.

One of the authors, Professor Bruce Neal, of the George Institute for Global Health at the University of Sydney, told MJA InSight that the research provided substantial reassurance that intensive lowering of BP was more likely to provide benefits in high-risk patients than produce harms.

“What doctors want to know is, if they lower a patient’s BP from 150 mmHg to 130 mmHg, is that going to be better than stopping at 140 mmHg”, Professor Neal said. “Our data strongly suggest that this is indeed the case, particularly for high-risk patients.”

However, he warned that the results did not mean that every patient should go straight onto three drugs for their hypertension. “Start with one drug, check for side effects then add the next”, Professor Neal said. “For many patients the best way to get lower BP with minimal side effects is to use half doses of multiple drugs.”

Professor Mark Nelson, the head of the discipline of general practice at the University of Tasmania, said the research reinforced the recommendations of the Heart Foundation to treat BP to target.

Professor Nelson said that generally both patients and doctors became less aggressive in lowering BP as they got closer to targets. However, this research showed there were benefits in getting BP lower.

It also showed that it was worth aiming for lower BP in the elderly as age subgroup analysis showed the same benefit in this high-risk group, Professor Nelson said.

The BP targets varied substantially in the 15 randomised controlled trials included. The three most conservative trials sought to meet or better group targets of 140–150 mmHg systolic and 85–90 mmHg diastolic, while targets in the most aggressive studies were 20–30 mmHg below these levels. On average there was a 7.5/4.5 mmHg difference between the more and less aggressive groups in BP levels achieved.

The researchers found that more intensive BP-lowering regimens produced an 11% reduction in the risk of major cardiovascular events compared to less intensive regimens, a 24% lower risk of stroke, an 11% reduced risk of end-stage kidney disease, a 10% reduction in the risk of albuminuria progression and a borderline significant reduction in retinopathy.

Intensive lowering did not show a statistically significant beneficial effect for heart failure, and did not lower the risk of cardiovascular death, non-cardiovascular death or all-cause death compared with less intensive BP control.

The authors said the data on adverse outcomes were not as clear. However, more intensive BP control did greatly increase the risk of hypotension in some trials, although the overall annual rate of severe hypotension was very low.

There was no clear difference in the rates of patients stopping medications between the intensive and less intensive groups.

“Some adverse effects were more common in the intensively treated groups, but there was no suggestion that more intensive regimens were likely to result in net harm”, the authors said.

“A range of research questions arise from this work, perhaps most importantly how best to achieve and maintain greater BP reductions in high-risk patients …”, the researchers said.

“It is apparent that low-dose combinations will be an important part of this solution but other approaches to improve treatment rates and adherence will be required.”

An editor’s summary of the research said although the study suggested that a target BP of 130/80 is likely to produce an additional overall benefit compared to a target of 140/90, more trials were needed to confirm this conclusion and to determine the best way to reach the lower target.

– Kath Ryan

1. PLoS Med 2012; Online 21 August

Posted 27 August 2012

10 thoughts on “Lower BP targets beneficial

  1. Billy says:

    In the 1970s a professor from New York presented a paper on the meta-analysis of life insurance BPs, which were in the trillions. His conclusion was that a BP of 106/64 did not shorten a life. This made a mockery of the then accepted level so I began to aim much lower. As the treatment available improved I was able to treat patients more aggressively and found postural hypotension was not a great problem but the usual other sequelae seemed to be reduced. Start aggressively early and more patients may reach 80 or 90 with a better quality of life and die of something other than hypertensive complications.

  2. Andy Piotrowski says:

    I await the article ” A Study on the Allowable causes of Death”…. never to be written

  3. Horst Herb says:

    I would agree with Jacob Boon IF, and only if, these studies would actually have quality years of life as an endpoint AND demonstrate that those actually improve with the intervention.
    “cardiovascular events” alone are no acceptable surrogate for quality of life. People becoming immobilized and in pain after a #NOF for a hypotensive spell might be no better off than people with some cardiovascular event (where the studies fail to list what the impact on quality of life actually was).

    If ethic committees would be a bit smarter they would cease giving approval to “studies” with surrogate endpoints designed to further solely the interests of the pharmaceutical companies, and rather DEMAND hard endpoints, such as overall survival rate and – better – change of intervention on quality years of life. Will take longer observation periods, and possibly more enrolled patients and cost more too – but then at least we would get an answer suitable to guide our management rather than mere bullshit disguised as science.

  4. Sue Ieraci says:

    Dr ARC, I have no doubt that some of the very old are there because of preventative measures earlier in life (though also because of good genetics). I am not arguing about using these measures in earlier life – I am arguing about stopping them when the potential benefits start to be outweighed by the risks. Strokes are not the only disabling conditions in old age – fractured neck of femur following a fall can also be “the beginning of the end”. Older people need a higher head of pressure to perfuse their brains – low BP can cause ischaemic stroke as well as falls.

  5. Dr. ARC says:

    I agree with the post of Jacob Boon. Many elderly people in their 80s & 90s are there because of successfully treated hypertension reducing the likelihood of stroke and end stage renal disease.
    I’m sure that the likes of Dame Elizabeth Murdoch who continues to do great philanthropic acts even as a centarian is partially due to effective medication and great genetics.
    I also believe that each case should be judged on its merits and should not solely be aged related.

  6. jacob boon says:

    The posts so far seem to miss the point which is about quality of life but not time of death. Th conclusions of the article include a 24% lower risk of stroke…that alone is sufficient justification for lowering targets as stroke is so disabling…life is much more worthwhile in the absence of neurological disability

  7. M Saha says:

    I totally agree with all of the above comments. Title of the Article, some contents and comments sound biased.

  8. Sue Ieraci says:

    I agree with the posters above, but would also remind us all that “preventative” measures don’t make a lot of sense in the very old. When we get to the stage that the side-effects outweigh the long-term benefits, it’s time to stop. I see lots of people over 85, even over 90, still on statins, antihypertensives and warfarin – all drugs with significant adverse effects and only long-term benefits. When one gets to that age, death will come from some cause. What do we think we are we preventing?

  9. Dr Horst Herb says:

    So the meta analysis shows NO BENEFIT for overall survival and yet they suggest more aggressive treatment on the mere assumption that it does not cause increased net harm? Only a partialist could have such a twisted view of what our patients expect from the treatment we subject them to, without even asking the funding taxpayer whether such “no increased survival benefit” was worth paying the extra money for (that would possibly have to be taken away from treatments that CAN demonstrate survival benefit)

  10. Thinus van Rensburg says:

    No quality of life due to the side effects of the beta blockers and breaking their hips from the postural drops in BP – but yes, they will not die sooner from their heart disease

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