Acute coronary syndrome (ACS) is one of the main causes of mortality worldwide and a frequent reason of hospital admission in patients aged 80 years or older,1 who show a higher risk for adverse events than younger patients.2 In recent decades, revascularisation and medical treatment have significantly reduced mortality and morbidity from ACS. However, elderly patients have consistently been under-represented in cardiovascular clinical trials, resulting in a paucity of evidence regarding the management of ACS in this scenario and these patients being less likely to receive therapeutic management according to guidelines.3 Whereas initially advanced age was considered a relative contraindication to invasive treatment of ACS, current cardiovascular practice stands solidly on an early invasive approach for clinically stable elderly patients, even in higher risk subgroups like diabetics,4 typically based on radial access and drug-eluting stents implantation.1,5 However, an apparent dilution of the benefits of an invasive strategy with increasing age has been reported and its efficacy in nonagenarians remains uncertain.1

Furthermore, frailty, and other geriatric conditions unique to this group, together with aspects of relevance to the older patients, such as quality of life, physical function, and independence, must be carefully evaluated due to their influence on care and outcomes.3

The aim of the present study was to describe the clinical characteristics, therapeutic management, and outcomes of patients undergoing coronary angiography (CA) for an ACS aged 80 years or older, in comparison with patients younger than 80.

This was a retrospective cohort study that included all consecutive patients diagnosed with ACS undergoing CA, admitted to a single tertiary hospital between January 2015 and December 2019.

ST-segment elevation was defined as 1mm raise in at least 2 contiguous leads of the electrocardiogram for longer than 30min, measured at the J-point, in the absence of left bundle-branch block.6 Besides, non-ST-segment elevation included ST-segment depression, transient ST-segment elevation, T-wave changes or normal repolarisation on electrocardiogram.7 Myocardial infarction was defined by elevation of cardiac troponin values above the reference limit with clinical evidence of myocardial ischaemia by electrocardiogram alterations, compatible regional wall motion abnormalities on imaging techniques or identification of a coronary thrombus by angiography.8

For purposes of comparison, 2 groups were formed, according to patient's age at admission: those aged ≥80 years or older, also called octogenarians, and those under 80 years old.

Data regarding demographics, clinical features, angiographic characteristics, management, and outcomes were retrospectively collected from patients’ electronic and paper medical records and files. A 12-month follow-up was performed, registering the occurrence of new coronary events, stroke, bleeding complications (defined according to the Bleeding Academic Research Consortium definitions9), and mortality. All data were recorded on a multipurpose database exclusively created for this study. The protocol was approved by the local ethical committee and patients’ informed consent was waived because it involved only analysis of data obtained during standard clinical practice.

The present study comprises a large series of invasively managed ACS in octogenarian patients, in comparison with those younger than 80 years old. The main findings in octogenarians in this study were as follows: (a) acute heart failure at admission (excluding cardiogenic shock) was more frequent in this group; (b) DAPT with aspirin and clopidogrel or single antiplatelet therapy, both at admission and at hospital discharge, were the most commonly used antithrombotic drug options; (c) identification and revascularisation of a culprit lesion was less frequent in this group; (d) new-onset AF and acute kidney disease were more frequent among octogenarians, whereas no differences were observed concerning bleeding complications; and (e) in-hospital and 1 year-mortality rates were higher, mainly due to cardiovascular causes.

Coronary artery disease is a leading cause of morbidity and mortality in older patients.10 With an ageing population and longer life expectancies, a progressively increasing proportion of patients presenting with an ACS are octogenarian.2 However, elderly patients have consistently been under-represented in most clinical trials in the field.11,12

As previously reported,13 in our cohort of octogenarians, classical cardiovascular risk factors were more prevalent than in the younger group, as well as chronic kidney disease,14 AF and stroke.15 Furthermore, other age-related clinical conditions share several predisposing factors with coronary artery disease, such as cognitive impairment or dementia.16

Among octogenarians, the proportion of patients presenting with STEMI (62.7%) was greater than those presenting with NSTEMI (37.9%), in contrast with available literature.17,18 This may be due to a selection bias, as only patients undergoing CA were included in our series. Conversely, even though the absolute number of patients with STEMI increases with age, it represents a smaller proportion of overall ACS admissions in the elderly due to the frequent presence of left bundle-branch block or nondiagnostic electrocardiograms in this population. Thus, in the National Registry of Myocardial Infarction, the proportion of patients with ACS and left bundle-branch block or nondiagnostic electrocardiograms increased from 5% and 23% within those <65 years old to 33.8% and 43% for those 85 years or older, respectively.3,11 Compared to these percentages, a smaller proportion of left bundle-branch block (3.7%) was observed among octogenarians included in the present study, most likely due to the previously mentioned selection bias.

Revascularisation of the culprit lesion was performed in 84.4% of patients under 80 years old and 73.3% of the octogenarians (P<.001), differences likely due to a higher prevalence of multivessel disease, calcification, and tortuosity, which have been attributed to advanced age.19

Even though over 90% of the cases in both groups underwent PCI, the proportion of patients who were revascularised with CABG was significantly higher among the younger group. Several studies have compared revascularisation outcomes with either PCI or CABG obtaining conflicting results. Whereas a meta-analysis of 66 studies observed that CABG was associated with higher 30-day and 1-year mortality rates,20 other series have described poorer short and long-term outcomes with PCI21,22 with other studies reporting no significant differences between both techniques with regards to all-cause death, myocardial infarction, and stroke.23 Although CABG more frequently achieves complete revascularisation compared to PCI, with a lower requirement for repeat revascularisation, the less invasive PCI approach may be more appropriate in older patients who are often frail and are more prone to periprocedural CABG complications, including stroke and neurocognitive decline.18 However, no randomised trials of PCI versus CABG solely restricted to an older patient cohort has been performed so far.

Regarding antithrombotic treatment, DAPT including aspirin and clopidogrel was prescribed in 76.5% of the ≥80-year-old group (P<.001), whereas DAPT with ticagrelor or prasugrel was more frequently used in the younger patients. The proportion of octogenarian patients treated with ticagrelor at hospital discharge was 17.3%, in accordance with that reported by LONGEVO study in a similar population.24 According to current guidelines,25 P2Y12 inhibitor selection must be guided by bleeding risk assessment. In fact, advanced age is a greater risk factor for haemorrhagic complications rather than recurrent ischaemic events following revascularisation.18,26 Therefore, in a high bleeding risk scenario, clopidogrel or ticagrelor may be suitable options, considering that the latter is contraindicated in case of previous intracranial haemorrhage, which is a more frequent condition among older patients.27 Moreover, prasugrel is not recommended in patients ≥75 years old, those with a body weight <60kg or with history of intracranial haemorrhage or ischaemic stroke; since it did not demonstrate any clinical benefit compared to clopidogrel in individuals with increased bleeding risk in the TRITON-TIMI 38 Trial.28 However, prasugrel prescription may be considered in selected patients in whom ischaemic risk is particularly high and does not have absolute contraindications.

As previously reported, ACS-related complications increase in frequency with age.29 Regarding STEMI in the National Registry of Myocardial Infarction, up to 11.7% of patients <65 years versus 44.6% of those ≥85 years old presented Killip–Kimball class≥II at admission.3 Likewise, among NSTEMI presentations, acute heart failure was present in 15% of those patients ≥75 years vs 6.3% of those <75 years of age.30 In our cohort, a significantly greater proportion of octogenarians, suffered acute heart failure at admission and during hospital stay, together with a higher percentage of patients showing severely reduced left ventricular ejection fraction at discharge. Regarding the occurrence of stroke before discharge, we did not observe a significant difference between both groups (1.5% in <80 years vs 2.1% in ≥80 years; P=.440), despite the higher incidence of post-infarction AF among the older group. Similarly, in the After Eighty trial, those patients over 80 years old randomised to early invasive strategy following NSTEMI had a 3% incidence of stroke during their hospital stay.1 However, at one year follow-up a significantly greater occurrence of ischaemic stroke was observed. Concerning other complications, acute kidney disease, particularly contrast-induced nephropathy, was more frequently observed among elderly patients in our study (12.4%), in contrast with a 2% incidence reported by Tegn et al.1 among invasively managed patients with NSTEMI. Such differences are likely due to the octogenarians in our study having a more impaired renal function at admission (baseline creatinine 1.4±0.7mg/dL in our series vs 1.15±0.5mg/dL in the study). With regards to major and life-threatening bleeding complications, we did not observe significant differences between groups, in accordance with some previous reports.1,31 However, other registries have described increased incidence of haemorrhagic complications in nonagenarians, highlighting that the risk-benefit balance must be carefully assessed, particularly at extreme chronological ages.18,32

Mortality in ACS significantly increases with age.18,33 In fact, it has been shown that the probability of in-hospital death rises by 70% for each 10-year increase in age.34 In our cohort, death during admission and after 1 year follow-up was significantly higher among the octogenarians (12.2% vs 5.1%; P<.001 for in-hospital mortality, 16.8% vs 3.8%; P<.001 for mortality at 1-year follow-up). In parallel with our findings, previous registries have reported 10% probability of dying during admission in patients ≥85 years old and up to 25% during the first year.11

In concordance with other previous studies,35,36 octogenarians in our series were less frequently enrolled in cardiac rehabilitation programmes. However, older patients may also benefit from such programmes, regardless of comorbidity status.37 Therefore, age must not be considered in isolation for clinical decision-making regarding ACS treatment in octogenarians, but rather integrated in a patient-centred assessment considering patient's preferences, expected quality of life and life expectancy.3,38

Compared with younger patients, octogenarians undergoing CA for ACS presented a higher prevalence of multivessel disease and a lower proportion of culprit lesion revascularisation. Clinical course included a higher incidence of acute heart failure, acute kidney disease, systolic ventricular dysfunction at discharge, and in-hospital mortality. At one year follow-up, ischaemic stroke and death were also more frequent among this group.

This investigation has not received any economic support from any public institutions, the commercial sector or non-profit bodies.

A. Jerónimo: conception and design of the project; analysis and interpretation of data; drafting of the manuscript. Z. Gómez-Álvarez: drafting of the manuscript. T. Romero-Delgado: drafting of the manuscript. C. Ferrera: analysis and interpretation of data. B. Hennessey: revision of the manuscript. F.J. Noriega: revision of the manuscript. R. Fernández-Jiménez: revision of the manuscript. J.C. Gómez-Polo: Analysis and interpretation of data; revision of the manuscript. A.I. Fernández-Ortiz: revision of the manuscript. A. Viana-Tejedor: revision of the manuscript.

There were no funding sources supporting this study.

None.