In-stent restenosis (ISR) is a clinical quandary in interventional cardiology which increases the risk of coronary stent failure, myocardial infarction, rehospitalization, and death. ISR occurs from neointimal proliferation or hyperplasia. The use of drug-eluting stents (DES) compared with bare metal stents (BMS) has decreased the incidence of ISR. However, ISR has no definitive management strategy. Thus, the Society for Cardiovascular Angiography and Interventions (SCAI) published an expert consensus statement on its management by Klein et al (SCAI Expert Consensus Statement on Management of In-Stent Restenosis and Stent Thrombosis, Journal SCAI, article in press, 2023).
Risk factors include diabetes, renal failure, acute coronary syndrome, female gender, and recurrent ISR. Technical factors such as stent underexpansion, stent fracture, multiple stent layers, and BMS increase the risk. Lastly, angiographic factors including lesion length (>20 mm), vessel diameter (<3 mm), chronic total occlusion, bifurcation lesion, multivessel coronary artery disease, and severe calcification augment the risk of ISR.
The use of intravascular imaging (intravascular ultrasound or optical coherence tomography) should be utilized to understand the pathophysiology of ISR. The choice of imaging can be decided based on the operator and center experience as each modality has its own advantages and disadvantages. The greater the number of stent layers enhance the risk of ISR, such that, a third layer of stents should be avoided. Treatment options include balloon angioplasty with a noncompliant balloon, cutting balloon, lithotripsy, laser angioplasty, and DES implantation. The role of drug coated balloons (DCB) remains uncertain. Further studies are necessary to elucidate its potential as an alternative treatment option. Intravascular imaging should also be applied to optimize the stent, mitigate ISR, and improve patient outcomes. In cases refractory to percutaneous coronary intervention, coronary artery bypass grafting may be contemplated in conjunction with a heart team approach and individualized patient assessment.
In conclusion, ISR remains a challenging dilemma in contemporary interventional cardiology practice. Coronary imaging is a valuable tool to comprehend the pathophysiology of ISR. Afterwards, an optimal treatment plan for balloon angioplasty, cutting balloon, lithotripsy, laser angioplasty, and/or DES can be determined. Meticulous planning and technique should be practiced to achieve procedural success. In addition, post-procedural evaluation using imaging should be considered to confirm stent or balloon angioplasty optimization to diminish repeat ISR. The future of interventional cardiology is luminous and the consensus statement aims to provide various treatment options for ISR.
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Dr. Kar has no conflicts of interest to report.
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