Dual antiplatelet therapy discontinued 9 months after percutaneous coronary intervention associated with improved morbidity and mortality

1. For patients with second-generation drug-eluting stents, discontinuation of dual antiplatelet therapy (DAPT) 9 months post-percutaneous coronary intervention (PCI) was associated with lower all-cause mortality, cardiovascular mortality, myocardial infarction (MI), and major bleeding events, compared to patients who continued DAPT after 9 months.

Evidence Rating Level: 2 (Good)

Study Rundown:  For patients who undergo percutaneous coronary intervention (PCI), selecting the duration of dual antiplatelet therapy (DAPT) requires weighing the risks of ischemia versus the risk of bleeding. Current guidelines recommend 6 months of DAPT for stable coronary disease, and 12 months for acute coronary syndrome. As well, for patients at higher risk of bleeding, DAPT for 1 to 3 months has been suggested. However, these guidelines stem from data with 1 to 2 year follow-up post-PCI. Therefore, this retrospective study aimed to identify optimal DAPT durations for second-generation drug-eluting stents, based on up to 13 years of follow-up. This study employed data from PCI patients in the Veterans Affairs Healthcare System, between 2006 and 2016. The study found that the risk of death from cardiovascular and noncardiovascular events was higher amongst those who discontinued DAPT earlier than 9 months compared to those who continued, though there was no difference in MI or bleeding events. Furthermore, other factors existed within the population that discontinued earlier, such as frailty and less healthy lifestyles, that could have confounded this association. Additionally, for patients who discontinued DAPT after 9 months, compared to those who continued, there were lower risks of all-cause mortality, cardiovascular mortality, myocardial infarction (MI), and major bleeding events.

Click here to read the study in JAHA

Relevant Reading: Second-Generation Drug-Eluting Stent Implantation Followed by 6- Versus 12-Month Dual Antiplatelet Therapy: The SECURITY Randomized Clinical Trial

In-Depth [retrospective cohort study]: The study population consisted of patients from the Veterans Affairs Healthcare System, between 2006 and 2016, with second-generation drug-eluting stents. Patients were excluded if they passed away within 14 days of PCI, had no outpatient DAPT prescription within 30 days post-PCI, or used ticlopidine DAPT. Then, prescriptions for P2Y₁₂ inhibitors were tracked over 18 months, with discontinuation of DAPT categorized into the time intervals 1-5 months, 6-9 months, 10-12 months, and 13-18 months post-PCI. Mortality and morbidity outcomes were compared between patients who continued versus discontinued DAPT in each of these time periods. In total, there were 40,882 patients analyzed, with a mean age of 65-66 years at index PCI, and median follow-up of 4.3 (IQR 2.4-6.5) years. The proportion of patients discontinuing DAPT in each time interval were 5.8% between 1 and 5 months, 6.3% in 6-9 months, 18.9% in 10-12 months, and 43.9%. The results demonstrated that there was a greater risk of all-cause mortality for discontinuation at 1-5 months (HR 2.17, 95% CI 1.94-2.43, p < 0.001) and 6-9 months (HR 2.27, 95% CI 2.05-2.51, p < 0.001), compared to continuation in these time intervals. Despite higher all-cause mortality, there was no significant difference in MI or bleeding events between those who continued versus discontinued in these time intervals, though there was increased risk of cardiovascular, noncardiac vascular, and noncardiovascular mortality. Furthermore, all-cause mortality was lower for those who discontinued at 10-12 months (HR 0.90, 95% CI 0.85-0.96, p < 0.01) and 13-18 months (HR 0.92, 95% CI 0.88-0.97, p < 0.01), compared to those who continued in these time intervals. There was also a lower risk of MI and major bleeding events amongst those who discontinued DAPT at 10-12 months (HR 0.74, 95% CI 0.68-0.80, p < 0.01 and HR 0.80, 95% CI 0.72-0.89, p < 0.01) respectively) and 13-18 months (HR 0.84, 95% CI 0.78-0.89, p < 0.01 and HR 0.79, 95% CI 0.73-0.86, p < 0.01 respectively). For stroke, the only significant difference was a higher risk for patients discontinued at 6-9 months (HR 1.46, 95% CI 1.15-1.84, p < 0.01). Overall, this study found that patients with second-generation drug-eluting stents who discontinued DAPT 9 months post-PCI had better mortality and morbidity outcomes, compared to those who continued DAPT.

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