Recurrent intra-stent coronary restenosis in a carrier of non-disease-specific antinuclear antibodies

Intracoronary in-stent restenosis (ISR) is a phenomenon that generally occurs between 3 and 6 months after stent placement. With the introduction of drug-eluting stents (DES), the incidence of ISR has decreased but not disappeared. We report a case of reiterant in-stent restenosis of an 81-year-old female patient who underwent multiple percutaneous coronary intervention and two coronary artery bypass surgeries. ISR is possibly associated with extra-stent, stent-related and intra-stent factors. Here, we excluded the first two and focused on the intra-stent factors that seem more likely in our case. A challenging diagnostic workup led us to the hypothesis of a coronary vasculitis potentially triggered by some component of the stent in a predisposed patient carrier of non-disease-specific ANA, with an exaggerated immune response. No recurrence of ISR occurred after the introduction of steroids. Biological and intra-stent causes of ISR should be taken into careful consideration to aim for the early detection of the underlying mechanism of restenosis and to embrace the best therapeutic strategy.