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This is a plain English summary of an original research article. The views expressed are those of the author(s) and reviewer(s) at the time of publication.
Routine invasive therapy for people aged over 75 with non-ST-elevation acute coronary syndromes reduced the risk of dying, having a heart attack or stroke, and need for further intervention. However, there was a higher risk of major bleeding compared to treating people with medication.
This is the largest review to date to gather the evidence on treatments for older people with smaller heart attacks or severe angina (chest pain). NICE recommend treating these “non-ST-elevation acute coronary syndromes” either with stents, to open narrowed arteries, or with medication depending on the person’s risk. These treatments are quite commonly used in younger people, but older people are less likely to receive them and these researchers wanted to see if there was evidence that they are missing out on the benefits.
The findings suggest that age is not a barrier to invasive therapy, but greater clarity is needed around the balance of risks and benefits for this group of people.
Why was this study needed?
“Acute coronary syndromes” describe a group of heart conditions caused by blockage of the blood vessels supplying the heart. In the classic heart attack, the damaged heart muscle shows as a raised ST segment on electrocardiogram (ECG). This is called ST-elevation myocardial infarction (STEMI). Chest pain with raised heart enzymes on blood tests but no ST elevation is called non-ST-elevation myocardial infarction (NSTEMI). Unstable angina is new or worsening chest pain without ECG features or elevated blood enzymes. Both NSTEMI and unstable angina may be collectively termed non-ST-elevation acute coronary syndromes (NSTEACS).
People with NSTEACS often receive an angiogram to see how well blood is flowing through the heart blood vessels. Any blockages may be treated using revascularisation procedures. Older people are more likely to present with NSTEACS than STEMI, yet less likely to receive revascularisation. Individual trials have shown inconsistent outcomes in this group.
This review gathered the evidence on revascularisation in older people with NSTEACS.
What did this study do?
This systematic review identified four randomised trials and three observational studies, including 20,540 people aged 75 and over presenting with non-ST-elevation acute coronary syndromes. Trials compared routine angiography and/or revascularisation, with medical management with or without selective revascularisation. Patient follow-up was between six months and five years.
Studies were assessed as high quality but lack of blinding in trials and loss to follow-up in observational studies were common sources of bias. Patient characteristics differed between intervention and control groups: those receiving routine interventions were more likely to be male, with high blood pressure or cholesterol and have had previous revascularisation. Studies also differed in their definition of conservative management and the revascularisation techniques used. Therefore, comparison across studies may not be completely like-for-like.
What did it find?
- Routine invasive therapy reduced the risk of people dying whilst in the (odds ratio [OR] 0.65, 95% confidence interval [CI] 0.53 to 0.79) in of two large cohorts and one trial reporting this outcome. Pooled results of all seven studies found that routine invasive therapy similarly reduced mortality at any follow-up time (OR 0.67, 95% CI 0.61 to 0.74).
- Invasive therapy also reduced the risk of heart attack (OR 0.56, 95% CI 0.45 to 0.70; five studies) and stroke (OR 0.53, 95% CI 0.30 to 0.95; three studies) compared to conservative management.
- Invasive therapy reduced the need for at 12 to 18 months in two similar trials reporting this outcome (OR 0.27, 95% CI 0.31 to 0.56).
- Management approach had no effect on the likelihood of being hospitalised for heart problems after six or 12 months later.
- Routine invasive therapy increased the chance of major bleeding whilst in the (OR 2.37, 95% CI 1.53 to 3.68; two studies) and at any follow-up time (OR 2.38, 95% CI 1.64 to 3.45; four studies). However, looking at study publication dates, rates of major bleeding have reduced in recent years.
What does current guidance say on this issue?
NICE guidelines, updated in 2013, recommend that treatment of non-ST-elevation myocardial infarction and unstable angina is based on the assessed risk of future cardiac events. People at high cardiac risk – a 3% or higher risk of dying within six months – should have a coronary angiography unless contraindicated (for example active bleeding) with percutaneous coronary intervention if needed.
The procedure should be performed as soon as possible and within 96 hours of admission to hospital. People at lower risk can be medically managed unless there is further evidence of restricted blood supply (ischaemia) indicating they should have angiography with PCI if needed.
What are the implications?
This review suggests that invasive therapy for older people with non-ST-elevation myocardial infarction or unstable angina may have greater benefits than previously thought. However, this needs to be balanced against the risk of major bleeding. Though age alone should not be a precluding factor, past medical history and risk factors need to be considered carefully.
The findings were weaker when looking only at randomised controlled trials, and the findings from more recent studies differed from older studies. This indicates a need for well-designed trials to bring greater certainty about the balance between risks and benefits of invasive therapy in older adults with acute coronary syndromes.
Citation and Funding
Gnanenthiran SR, Kritharides L, D'Souza M, et al. Revascularisation compared with initial medical therapy for non-ST-elevation acute coronary syndromes in the elderly: a meta-analysis. Heart. 2017. [Epub ahead of print].
No funding information was provided for this study.
Bibliography
NICE. Unstable angina and NSTEMI: early management. CG94. London: National Institute for Health and Care Excellence; 2013.
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