Procedural complexity should be considered when deciding duration of dual antiplatelet therapy

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Alaide Chieffo

Gennaro Giustino and others report in the Journal of American College of Cardiology that—alongside other established risk factors—procedural complexity “is an important parameter to take in account in tailoring upfront duration of dual antiplatelet therapy (DAPT)”. In this interview, Giustino and co-author Alaide Chieffo discuss the definition of “complex” percutaneous coronary intervention (PCI) and the implications of their study.

What is meant by the term “complex PCI”?

Complex PCI can be defined as a procedure in patients with severe coronary artery disease requiring advanced interventional techniques, such as multiple stenting, bifurcation stenting, chronic total occlusion revascularisation, lesion decalcification or haemodynamic support. Since patients with more extended coronary artery disease burden may be more likely to have a greater prevalence of comorbid conditions (eg. diabetes, chronic kidney disease, left ventricular dysfunction, etc.), they remain at greater risk of short- and long-term adverse cardiac events.

What was the rationale for your study?

Recently, several post-hoc risk scoring system have been developed to predict future ischaemic and bleeding risk after PCI with drug-eluting stents and possibly inform clinical decision-making on duration and potency of DAPT (such as the DAPT score or the PARIS risk score). An important limitation of these scoring systems is that they do not incorporate markers of procedural complexity in their predictive models.

After PCI with drug-eluting stents, DAPT has been demonstrated to reduce the risk of myocardial infarction and stent thrombosis at the expenses of an increased risk of bleeding. We, therefore, hypothesised that complex PCI—defined as the composite of three vessels treated; ≥3 stents implanted; ≥3 lesions treated; bifurcation with two stents implanted; total stent length >60mm; or chronic total occlusion—may constitute an important clinical parameter to guide clinical decision-making in the upfront duration of DAPT after coronary stenting. We chose our definition of complex PCI on the basis of: (i) previous published data linking these features to thrombotic risk, (ii) clinical judgment of the investigators, (iii) data availability.

Gennaro Giustino

What were the key findings of your study?

This study was a large, international, collaborative, patient-level pooled analysis of six randomised controlled trials that included more than 9,000 patients randomised to different DAPT durations. The objective of this study was to investigate the efficacy and safety of long-term (≥12 months) versus short-term (three or six months) DAPT with aspirin and clopidogrel according to PCI complexity. We found that, in patients undergoing complex PCI, the use of prolonged DAPT was associated with a nearly 50% reduction in the risk of cardiac death, myocardial infarction or stent thrombosis in the complex PCI group, with significant treatment effect heterogeneity compared with the non-complex PCI group. Of note, the magnitude of the benefit of prolonged DAPT appeared to be greater per increase in procedural complexity. As expected, prolonged DAPT was associated with greater risk for bleeding, which however was uniform between complex and non-complex PCI patients.

In a complex patient, how do you balance the risk of bleeding with the risk of ischaemic events?

Our study introduces procedural complexity as an important variable to take into account to risk-stratify patients and guide decision-making surrounding duration and potency of DAPT for secondary prevention of adverse cardiac events. In current practice, many of the decisions regarding antiplatelet therapies are made at the time of the procedure. Our study suggests that after complex percutaneous coronary stenting, at least one year of DAPT should be applied, regardless of the clinical presentation (stable versus acute coronary syndrome). Of course, other clinical risk factors need to be taken into account at the time of clinical decision-making. In general, an important limitation of risk scores is that they do not capture the wide range of clinical variables that can be encountered in real-world practice. Our study may aid physicians in better characterising the individual thrombotic risk and take the  right decisions surrounding antiplatelet therapies for prevention of cardiac ischaemic events.

Gennaro Giustino is at the The Zena and Michael A Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, USA

Alaide Chieffo is at the San Raffaele Scientific Institute, Interventional Cardiology Unit, Milan, Italy