Dual antiplatelet therapy (DAPT) has long been utilized as a treatment option for patients with minor ischemic stroke or high-risk transient ischemic attack (TIA). However, recent findings from the INSPIRES trial suggest that DAPT may have potential benefits beyond the currently recommended time window and symptom severity. This article will analyze the study and discuss the implications of these results.
Traditionally, DAPT has been recommended within 24 hours of symptom onset and for patients with minimal stroke symptoms. However, the INSPIRES trial administered DAPT within 72 hours and included patients with minor ischemic stroke (NIHSS score ≤ 5) and high-risk TIA. The results showed a significant decrease in new stroke occurrences within 90 days when DAPT with clopidogrel and aspirin was used compared to aspirin alone (7.3% vs. 9.2%). This finding suggests that the time window for initiating DAPT treatment may be expanded.
Weighing the Benefits and Risks
Although the reduction in new stroke occurrence is promising, the INSPIRES trial also revealed a doubling in moderate-to-severe bleeding at 90 days in the DAPT group compared to the aspirin-only group. This finding highlights the importance of balancing the benefits and risks of DAPT. The authors of the study acknowledge the increased bleeding risk with DAPT and emphasize the need for careful consideration when deciding on the treatment.
With the addition of the INSPIRES trial, there is now evidence supporting the extension of the time window for DAPT initiation to 72 hours. However, it is important to note that this timing should still be interpreted as “as soon as possible, but within 72 hours.” The loading dose of clopidogrel should not be omitted, as it is crucial for effective treatment. Clinicians should carefully evaluate each patient’s bleeding risk and weigh the potential benefits of stroke prevention against the increased risk of bleeding events.
Based on the calculations by Anthony Kim, MD, roughly 19 fewer strokes and 5 additional moderate-to-severe bleeding events would be expected for every 1,000 patients treated with DAPT compared to aspirin alone. This data suggests that DAPT has the potential to significantly reduce the occurrence of strokes in patients with TIA or mild stroke. However, the increased bleeding risk should not be overlooked, and clinicians must consider this when deciding on the appropriate treatment strategy.
Despite the potential benefits of DAPT, recent studies have shown its underutilization in clinical practice. A study conducted from 2018 to 2021 found that only slightly over 40% of stroke patients with an NIHSS score of 3 or less were prescribed DAPT after a minor stroke or TIA. This underutilization suggests that there may be a gap between research evidence and clinical practice, highlighting the need for better dissemination of new guidelines and recommendations.
It is important to acknowledge the limitations of the INSPIRES trial. The study cohort excluded patients with presumed cardioembolic TIA or ischemic stroke, moderate or severe stroke, and those already on DAPT or intensive statin therapy. Additionally, the study population was predominantly Han Chinese, which may limit the generalizability of the results to other populations. Furthermore, the trial did not investigate other antiplatelet regimens.
The INSPIRES trial provides evidence for the potential benefits of DAPT for minor ischemic stroke and high-risk TIA beyond the current recommended time window and symptom severity. The findings highlight the need for careful consideration of the risks and benefits of DAPT, especially the increased bleeding risk. As the field of stroke prevention continues to evolve, it is crucial for clinicians to stay up-to-date with the latest research and guidelines to ensure the best possible outcomes for patients.
Leave a Reply