https://doi.org/10.1007/s00392-025-02737-x
1Deutsches Herzzentrum München Klinik für Herz- und Kreislauferkrankungen München, Deutschland; 2Deutsches Herzzentrum München München, Deutschland; 3Helios Klinikum München West Medizinische Klinik I, Kardiologie München, Deutschland
Background:
The optimal duration of dual antiplatelet therapy (DAPT) following treatment of in-stent restenosis (ISR) remains uncertain, as there are no randomized controlled trials (RCTs), particularly for patients treated with drug-coated balloons (DCB).
Objective: To determine whether the impact of dual antiplatelet therapy (DAPT) duration on outcomes after in-stent restenosis (ISR) differs between patients treated with drug-eluting stents (DES) versus drug-coated balloons (DCB).
Methods:
We evaluated 6,273 ISR patients drawn from a real-world cohort of 2.3 million individuals in the Observable databank. DAPT duration (3, 6, or 12 months) was determined from pharmacy reimbursement records to ensure robust assessment of adherence outside clinical trial settings. The primary endpoint was time to major adverse cardiovascular events (MACE: death, myocardial infarction, or stroke) after stoppage of DAPT, with secondary endpoints including individual events.
Results:
Out of 5,799 ISR patients, 4,429 were assigned to the above-mentioned groups (1,214 DCB; 3,215 DES). Baseline demographic characteristics were comparable between the groups.
In the DES group (3 months: n=832; 6 months: n=1,425; 12 months: n=958), the incidence of MACE over three years decreased with longer DAPT duration: 23.9% for 3 months, 19.8% for 6 months (p=0.05), and 14.2% for 12 months (p=0.02). Among those with an event, the median time to MACE increased from 48.3 weeks for 3 months of DAPT to 58.9 weeks for 6 months, and to 71.3 weeks for 12 months.
Conversely, in the DCB group (3 months: n=486; 6 months: n=431; 12 months: n=297), prolonging DAPT duration did not significantly influence MACE outcomes. Event incidences over three years were 29.0% for 3 months, 19.5% for 6 months, and 16.8% for 12 months, but all pairwise comparisons were non-significant (3 vs 6 months: p=0.84; 3 vs 12 months: p=0.55; 6 vs 12 months: p=0.60). The median time to MACE was 71.0 weeks for 3 months of DAPT, 57.2 weeks for 6 months, and 55.2 weeks for 12 months.
Conclusion:
Prolonged DAPT after ISR treatment substantially increases the time to major cardiovascular events in patients treated with DES, but not in those treated with DCB. These findings highlight the need for device-specific DAPT strategies.