Invasive vs. conservative management of older patients with non-ST-elevation acute coronary syndrome: individual patient data meta-analysis

Abstract

Background and aims: Older patients with non-ST-elevation acute coronary syndrome (NSTEACS) are less likely to receive guideline-recommended care including coronary angiography and revascularization. Evidence-based recommendations regarding interventional management strategies in this patient cohort are scarce. This meta-analysis aimed to assess the impact of routine invasive vs. conservative management of NSTEACS by using individual patient data (IPD) from all available randomized controlled trials (RCTs) including older patients.

Methods: MEDLINE, Web of Science and Scopus were searched between 1 January 2010 and 11 September 2023. RCTs investigating routine invasive and conservative strategies in persons >70 years old with NSTEACS were included. Observational studies or trials involving populations outside the target range were excluded. The primary endpoint was a composite of all-cause mortality and myocardial infarction (MI) at 1 year. One-stage IPD meta-analyses were adopted by use of random-effects and fixed-effect Cox models. This meta-analysis is registered with PROSPERO (CRD42023379819).

Results: Six eligible studies were identified including 1479 participants. The primary endpoint occurred in 181 of 736 (24.5%) participants in the invasive management group compared with 215 of 743 (28.9%) participants in the conservative management group with a hazard ratio (HR) from random-effects model of 0.87 (95% CI 0.63-1.22; P = .43). The hazard for MI at 1 year was significantly lower in the invasive group compared with the conservative group (HR from random-effects model 0.62, 95% CI 0.44-0.87; P = .006). Similar results were seen for urgent revascularization (HR from random-effects model 0.41, 95% CI 0.18-0.95; P = .037). There was no significant difference in mortality.

Conclusions: No evidence was found that routine invasive treatment for NSTEACS in older patients reduces the risk of a composite of all-cause mortality and MI within 1 year compared with conservative management. However, there is convincing evidence that invasive treatment significantly lowers the risk of repeat MI or urgent revascularisation. Further evidence is needed from ongoing larger clinical trials.

Keywords: Acute coronary syndrome; Coronary angiography; Myocardial infarction; Older adults; Percutaneous coronary intervention.

Structured Graphical Abstract

Using individual patient-level data we show that the risk of myocardial infarction and unplanned urgent revascularization is lower in older patients with non-ST-elevation acute coronary syndrome (NSTEACS) treated with a routine invasive strategy compared to a conservative medical approach. The risk of a composite endpoint of all-cause mortality and reinfarction showed weaker evidence of a potentially lower risk for an invasive strategy, while we observed no evident difference for all-cause mortality, cardiovascular death, and stroke. CI, confidence interval; HR, hazard ratio; MI, myocardial infarction.

Figure 1

Study selection. Flow chart depicting studies screened and included in final analysis

Figure 2

Adverse outcomes 1 year post-randomization. Plots presenting hazard ratios and 95% confidence intervals for the comparison of participants in the invasive group vs. the conservative group using random-effects Cox models to adjust for within-study clustering. The numbers in the invasive group and conservative group columns represent the number of events/total number of participants in each group. Denominators are different for cardiovascular death, due to missingness of this outcome in one study, and for the revascularization endpoint, because six participants were missing follow-up time values. The composite endpoint includes all-cause mortality and/or myocardial infarction

Figure 3

Subgroup analyses. Hazard ratios for subgroup analyses based on age groups, sex, diabetes mellitus, history of previous percutaneous coronary intervention, troponin levels, and history of previous coronary artery bypass graft surgery for the composite endpoint (A) and myocardial infarction (B) 1 year post-randomization. Random-effects Cox models were fitted to adjust for within-study clustering. P-values presented are for interaction terms. P-value for the age group variable represents the trend P-value. The numbers in the invasive group and conservative group columns represent the number of events/total number of participants in each group. The composite endpoint includes all-cause mortality and/or myocardial infarction