SPRINT trial – hypertension. Inside Health 2/2/16

Notes on SPRINT
Trial: http://www.nejm.org/doi/full/10.1056/NEJMoa1511939#t=articleResults

also of note
http://www.cochrane.org/CD006742/HTN_benefits-of-antihypertensive-drugs-for-mild-hypertension-are-unclear
http://cks.nice.org.uk/chronic-kidney-disease-not-diabetic#!scenariorecommendation:5
http://cks.nice.org.uk/hypertension-not-diabetic

This was a
randomised controlled trial 9391 people without diabetes at high risk of CVS events
and with BP of over 130mm HG
not blinded

average bp 121 in rx group, 134.6 in normal rx group
outcomes – MI, stroke, HF, death from CVS causes
2 groups target either less than 140 or less than 120mmHg
stopped early after 3 and a half years (planned for 5 years) due to more aggressive BP lowering looking like much better option – death rates between the groups started to change after 2 years

The relative risk of death from cardiovascular causes was 43% lower with the intensive intervention than with the standard treatment (P=0.005) (Table 2).
The numbers needed to treat to prevent a primary outcome event, death from any cause, and death from cardiovascular causes during the median 3.26 years of the trial were 61, 90, and 172, respectively.

double the amount of serious adverse effects

A total of 220 participants in the intensive-treatment group (4.7%) and 118 participants in the standard-treatment group (2.5%) had serious adverse events that were classified as possibly or definitely related to the intervention (hazard ratio, 1.88; P<0.001 – low blood pressure ,faints , slow heart rate
double the amount of acute kidney injury/failure from 2.6% to 4.4%
approaching  1 in 20 people .

2 Responses to “SPRINT trial – hypertension. Inside Health 2/2/16”

  1. Dr Paul Travis February 3, 2016 at 5:09 pm #

    Hi Margaret,
    I was listening to the Inside Health podcast whist walking the dog this morning (the joys of being a retired GP!) about the SPRINT Trial. I’ve managed to spend some time doing a little digging around the trial design, results and critiques, and have to say I couldn’t agree with you more. Professor Tony Heagerty, Professor of Medicine and Cardiac Centre Lead in the Institute of Cardiovascular Sciences, President of the British Hypertension Society and a consultant to Daiichi Sankyo, said it was a “landmark study” – quoting the press release, and provided an “unequivocal answer”.

    Well, I don’t entirely agree with the learned professor’s opinion.

    Firstly, raised blood pressure, of course, is not itself a disease. It is a risk factor for possible diseases in the future. In this study, diabetics were excluded. That’s quite a sizeable proportion of the population and the ones with more risk factors. At least we can safely say, if we are to adhere strictly to Evidence Based Medicine, that these trial results do not apply to our diabetic population (most of whom haven’t been diagnosed yet because we don’t measure fasting insulin levels — another story) or ‘older adults residing in nursing homes or assisted-living facilities’. Actually, only about 1 in 6 of the hypertensive population in GP-land would have been eligible for the study. Hardly representative.

    The study wasn’t blinded and therefore easy for bias to have an effect, particularly when the treatment effect is small. Stopping a trial early with no single endpoint makes me equally skeptical, and again has the effect of making any effect look bigger than it really is. It may be statistically significant (bearing in mind what that really means) but that doesn’t easily translate to ‘real world’ patient management.

    So, the result of intense BP treatment was that one death was avoided for every 300 people treated per year, except they experienced more fatal or life-threatening events, including very low blood pressure and fainting… and increased risk of kidney failure.

    And why is the overall death rate in the intensive treatment group lower than the death rate from CVD?? Doesn’t make any sense. Perhaps the anti-hypertensives (whatever they were – we are not told) have some anti-cancer properties or something?!? Or perhaps it is lifestyle intervention that has the greater effect? You mentioned the need for further studies on the programme. I agree. These findings need to be independently verified. I can’t help thinking that they got the result they were looking for. That’s not science.

    OK, I agree with the professor that over time a successful treatment will bring down the NNT, but on the other hand, side effects tend to increase over time, and these effects should not be ignored as the medication is taken for life.

    I want to make it quite clear, however, that managing hypertension is a serious matter indeed, having seen the devastation caused by CVD, but an aggressive approach does not apply to the whole population. Treating numbers is one thing, treating people is another. Clearly, we must exercise our clinical judgement, and in this day and age discuss uncertainties with our patients rather than print off a prescription for yet another wonder-drug and have them out of your surgery before they question your clinical excellence (or should that read ‘arrogance’??). My aim is/was to maintain or improve the quality of life for my patients. I fear that Professor Heagerty’s prediction that NICE will need to lower the target BP for GPs to achieve will, in many cases, lead to more complications and a poorer quality of life. Remember statins?

    • carol February 18, 2016 at 8:31 am #

      Are bp meds a waste of time. I have high blood pressure and take two meds which I would like to come off. Tried coming off them by myself but I got a racing heart and felt very unwell. How do you take yourself off them.

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