Elderly patients suffering the most common type of heart attack may benefit from more invasive treatment, research has shown. The study draws on data captured over seven years from 1500 patients aged 80 or over. It was conducted by researchers from the National Institute of Health Research Health Informatics Collaborative (NIHR-HIC), led by Imperial College Healthcare NHS Trust and Imperial College London.
The research looks at elderly patients admitted to hospital with a type of heart attack called NSTEMI (non-ST segment elevated myocardial infarction). It found patients who underwent invasive treatment with a coronary angiogram, followed up with bypass surgery or coronary stenting as appropriate, had higher survival rates than those who were treated with medication alone. Patients who had coronary angiograms were also less likely to be re-admitted to hospital with a second heart attack or heart failure.
Coronary angiograms are specialist X-rays to identify blockages in the blood supply to the heart. They can help a clinician determine the cause of an NSTEMI heart attack and decide on effective treatment, such as increasing blood flow through a coronary stent or bypass grafting.
Previous trials have shown increased survival rates in younger patients with NSTEMI heart attacks following invasive treatment, but there has been conflicting evidence as to whether these benefits extend into patients over 80. Only 38 percent of NSTEMI patients in this older age group currently receive invasive treatment, compared to 78% of the under 60s.
Dr Amit Kaura, lead author of the research, British Heart Foundation clinical research fellow and NIHR clinical research fellow with the National Heart and Lung Institute at Imperial College London explained: "Because there has been no clear consensus on how best to manage elderly patients with this type of heart attack, many doctors have erred on the side of caution, not wanting to risk complications in their more vulnerable patients. These results show they can now be more confident of the benefits that invasive treatment can bring for this group."
The study, funded by the NIHR Imperial Biomedical Research Centre, identified just under 2,000 patients aged over 80 who were diagnosed with an NSTEMI heart attack at five hospitals between 2010 and 2017. To ensure the robustness of the study, the researchers used sophisticated statistical techniques to apply the kind of criteria used in a clinical trial, to determine which of these patients would be included in the analysis. In total, 1,500 patients were included, with just over half having invasive treatment. After five years, 31% of those in the invasive treatment group had died, compared to 61% in the non-invasive group.
The team estimate that if all patients had received invasive treatment, just 36% would have died, compared to 55% if all had received non-invasive treatment. These figures take into account over 70 variables that might have affected prognosis, such as other medical conditions.
The analysis also showed that patients were at no greater risk of stroke or bleeding if they received invasive treatment, as there were similar rates across both groups. Patients who had invasive treatment were also a third less likely to be re-admitted to hospital for heart failure or heart attack.
Kaura said: "The gold standard is to base treatment decisions on evidence from randomised control trials, but that doesn't yet exist for this group of patients. In the interim, we've done the next best thing, by looking at retrospective data gathered from these five large hospitals and using it like a clinical trial. The results are clear: clinicians should positively consider invasive management for any patients over 80 diagnosed with an NSTEMI."
The data used in the study was gathered through the National Institute for Health Research Health Informatics Collaborative (NIHR-HIC), which involves: Imperial College Healthcare NHS Trust, Oxford University Hospitals NHS Foundation Trust, University College London Hospitals NHS Foundation Trust, King's College Hospital NHS Foundation Trust and Guy's and St Thomas' NHS Foundation Trust.
Abstract
Background: Previous trials suggest lower long-term risk of mortality after invasive rather than non-invasive management of patients with non-ST elevation myocardial infarction (NSTEMI), but the trials excluded very elderly patients. We aimed to estimate the effect of invasive versus non-invasive management within 3 days of peak troponin concentration on the survival of patients aged 80 years or older with NSTEMI.
Methods: Routine clinical data for this study were obtained from five collaborating hospitals hosting NIHR Biomedical Research Centres in the UK (all tertiary centres with emergency departments). Eligible patients were 80 years old or older when they underwent troponin measurements and were diagnosed with NSTEMI between 2010 (2008 for University College Hospital) and 2017. Propensity scores (patients' estimated probability of receiving invasive management) based on pretreatment variables were derived using logistic regression; patients with high probabilities of non-invasive or invasive management were excluded. Patients who died within 3 days of peak troponin concentration without receiving invasive management were assigned to the invasive or non-invasive management groups based on their propensity scores, to mitigate immortal time bias. We estimated mortality hazard ratios comparing invasive with non-invasive management, and compared the rate of hospital admissions for heart failure.
Findings: Of the 1976 patients with NSTEMI, 101 died within 3 days of their peak troponin concentration and 375 were excluded because of extreme propensity scores. The remaining 1500 patients had a median age of 86 (IQR 82–89) years of whom (845 [56%] received non-invasive management. During median follow-up of 3·0 (IQR 1·2–4·8) years, 613 (41%) patients died. The adjusted cumulative 5-year mortality was 36% in the invasive management group and 55% in the non-invasive management group (adjusted hazard ratio 0·68, 95% CI 0·55–0·84). Invasive management was associated with lower incidence of hospital admissions for heart failure (adjusted rate ratio compared with non-invasive management 0·67, 95% CI 0·48–0·93).
Interpretation: The survival advantage of invasive compared with non-invasive management appears to extend to patients with NSTEMI who are aged 80 years or older.
Funding: NIHR Imperial Biomedical Research Centre, as part of the NIHR Health Informatics Collaborative.
Authors
Amit Kaura, Jonathan A C Sterne, Adam Trickey, Sam Abbott, Abdulrahim Mulla, Benjamin Glampson, Vasileios Panoulas, Jim Davies, Kerrie Woods, Joe Omigie, Anoop D Shah, Keith M Channon, Jonathan N Weber, Mark R Thursz, Paul Elliott, Harry Hemingway, Bryan Williams, Folkert W Asselbergs, Michael O'Sullivan, Graham M Lord, Narbeh Melikian, Thomas Johnson, Darrel P Francis, Ajay M Shah, Divaka Perera, Rajesh Kharbanda, Riyaz S Patel, Jamil Mayet
[link url="https://www.sciencedaily.com/releases/2020/08/200827205411.htm"]Imperial College London material[/link]
[link url="https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30930-2/fulltext"]The Lancet abstract[/link]