Comparison Between Ticagrelor and Clopidogrel in Elderly Patients with an Acute Coronary Syndrome: Insights from the SWEDEHEART Registry
Due to past evidence and guidelines, the use of ticagrelor after myocardial infarction is increased. However, there is a limited study conducted for investigating the comparison between ticagrelor and clopidogrel for their efficacy and safety in older myocardial infarction (MI) patients. Szummer and colleagues (2020) published a study titled “Comparison Between Ticagrelor and Clopidogrel in Elderly Patients with Acute Coronary Syndrome: Insights from the SWEDEHEART Registry” in the American Heart Association Journal. The summary of the study is given below:
Objectives:
To investigate and compare clinical outcomes with ticagrelor versus clopidogrel in myocardial infarction patients ≥80-year-old.
Method:
Observation study was conducted for all patient ≥80 years who were discharged with the prescribed treatment of aspirin in combination with either clopidogrel (60.2%) or ticagrelor (39.8%) post a MI between 2010 and 2017 registered in the national registry Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART). To adjust for differences in -hospital therapies, demographics, and medications; inverse probability treatment weighting was used in Cox regression models. The primary ischemic findings (MI, death, or stroke), and bleeding were acquired from national registries at 1 year. A sensitivity analysis was performed in <80-year-old patients.
Findings:
The study reports that in MI patients with ≥80 years who were treated with ticagrelor, lower risk for the combined outcome of readmission, death because of myocardial infarction or stroke was not found. Even if the risk of stroke and myocardial infarction alone was less, the risk of bleeding and death was higher as compared to patients treated with clopidogrel. These findings suggest that the current guideline recommendations should be applied with caution in elderly patients and that expectations for the same efficacy and safety might not be evident in clinical trials.
Limitation:
Authors acknowledge that the study only adjusted for known factors by Inverse probability treatment weighting (IPTW) in the models; hence residual confounding remains possible. There was a considerable difference in the number of patients treated invasively at baseline with clopidogrel versus ticagrelor, but this was balanced after adjustment with IPTW in both the groups. Authors also acknowledge that analysis might be unbiased as the study only focuses on endpoints that are related to the study. The study included all data to treat, and early termination of drugs was not accounted for. The cause of death is unknown.
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