A systematic review and meta-analysis on the effectiveness of an early invasive strategy compared to a conservative approach in elderly patients with non-ST elevation acute coronary syndrome

Background: Elderly patients, 65 years old and older, largely represent (>50 %) of hospital-admitted patients with acute coronary syndrome (ACS). Data are conflicting comparing efficacy of early routine invasive (within 48-72 hours of initial evaluation) versus conservative management of ACS in this population. Objective: We aimed to determine the effectiveness of routine early invasive strategy compared to conservative treatment in reducing major adverse cardiovascular events in elderly patients with non-ST elevation (NSTE) ACS. Data Sources: We conducted a systematic review of randomized controlled trials through PubMed, Cochrane, and Google Scholar database. Study Selection: The studies included were randomized controlled trials that evaluated the effectiveness of invasive strategy compared to conservative treatment among elderly patients > 65 years old diagnosed with NSTEACS. Studies were included if they assessed any of the following outcomes of death, cardiovascular mortality, myocardial infarction (MI), stroke, recurrent angina, and need for revascularization. Five articles were subsequently included in the meta-analysis. Data Extraction: Three independent reviewers extracted the data of interest from the articles using a standardized data collection form that included study quality indicators. Disparity in assessment was settled by an independent adjudicator. Data Synthesis: All pooled analyses were based on fixed effects model. A total of 2,495 patients were included, 1337 in the invasive strategy group, and 1158 in the conservative treatment group. Results: Meta-analysis showed less incidence of revascularization in the invasive (2%) over conservative treatment groups (8%), with overall risk ratio of 0.31 (95% CI 0.16-0.61, I2 =0%). There was also less incidence of stroke in the invasive (2%) versus conservative group (3%) but this was not statistically significant. A significant benefit was noted in the reduction of all-cause mortality (RR 0.63, 95% CI 0.55-0.72, I2=84%) and myocardial infarction (RR 0.62, 95% CI 0.49-0.79, I2=63%) but with significant heterogeneity. Conclusion: There was a significantly lower rate of revascularization in the invasive strategy group compared to the conservative treatment group. In the reduction of all-cause mortality and MI, there was benefit favoring invasive strategy but with significant heterogeneity. These findings do not support the bias against early routine invasive intervention in the elderly group with NSTEACS. However, further studies focusing on the elderly with larger population sizes are still needed.