Abstract Body (Do not enter title and authors here): Research Question
Does the impact of dual antiplatelet therapy (DAPT) duration on outcomes after in-stent restenosis (ISR) differ between patients treated with drug-eluting stents (DES) versus drug-coated balloons (DCB)?
Methods
We evaluated 6,273 ISR patients (1,817 DCB; 3,982 DES) drawn from a real-world cohort of 2.3 million individuals in the “OBSERVABLE” databank. DAPT duration after treatment of ISR (3, 6, or 12 months) was determined from pharmacy reimbursement records for assessment of medication adherence outside clinical trial settings. The primary endpoint was time to major adverse cardiovascular events from cessation of DAPT (MACE: death, myocardial infarction, or stroke), with secondary endpoints including individual events and bleeding.
Results
Demographic characteristics were similar between the two groups, with a mean age of 70.0 years and 25.8% female among DES patients, and 70.3 years and 28.7% female among DCB patients. In the DES group, longer DAPT duration was associated with a significant delay in the occurrence of MACE: patients on 12 months of DAPT had an average time to MACE of 48.3 weeks, which increased to 58.9 weeks with 26 weeks of DAPT, and further to 71.3 weeks with 52 weeks of DAPT. The increase in median time to event was statistically significant, with a p-value of 0.05 for the comparison between 12 and 26 weeks, and p < 0.01 for 26 to 52 weeks. In contrast, in the DCB group, extending DAPT did not significantly influence outcomes, with p-values of 0.83 and 0.55 for the respective comparisons. Notably, prolonging DAPT duration resulted in a higher incidence of bleeding complications in both groups.
Conclusion
Prolonged DAPT after ISR treatment increases the time to major cardiovascular events in patients treated with DES, but not in DCB. These findings highlight the need for device-specific DAPT strategies, as a longer DAPT regimen may benefit DES patients but does not confer the same advantage for those treated with DCB.