30 Aug Complex Stent Procedures May Require Longer Period of Antiplatelet Therapies

MedicalResearch.com Interview with:

Dr. Gennaro Giustino

Gennaro Giustino MD
Resident Physician – Department of Medicine
The Icahn School of Medicine at Mount Sinai

MedicalResearch.com: What is the background for this study?

Response: A period of dual antiplatelet therapy (DAPT) is required after percutaneous coronary intervention (PCI) with drug-eluting stents (DES). The pathophysiological rationale for DAPT after DES-PCI is predicated on the need to prevent stent-related thrombotic complications while vascular healing and platform endothelialization are ongoing, a process that seems to last between 1 and 6 months with new-generation DES. Whether to extend DAPT after this mandatory period in order to provide a broader atherothrombotic risk protection (for stent-related and non-stent-related atherothrombotic events) is currently a matter of debate. Current guidelines recommend at least 6 months of DAPT after PCI in patients with stable coronary artery disease (CAD) and at least 12 months of DAPT in patients presenting with acute coronary syndrome (ACS). While, several risk scores have been developed to guide clinical decision making for DAPT intensity and duration (namely the DAPT score and the PARIS risk scores) little attention has been payed so far to PCI complexity and the extent of CAD to guide duration of DAPT. In fact irrespective of clinical presentation, patients undergoing more complex PCI procedure (likely due to greater coronary atherosclerotic burden) may remain at greater risk for ischemic events and therefore may benefit of prolonged, or more intense, DAPT.

MedicalResearch.com: What are the main findings?

Response: In our study, which is a patient level pooled analysis of randomized controlled trials of DAPT durations (including more than 9000 randomized patients) we investigated the safety and efficacy of 12 or 24 months of DAPT versus 3 or 6 months after complex PCI (defined as a procedure with at least one of the following characteristics: 3 vessels treated; ≥3 stents implanted; ≥3 lesions treated; bifurcation with 2 stents implanted; total stent length >60 mm; or chronic total occlusion).

The main findings of our study are as follows:

(1) Patients who underwent complex PCI had higher risk of major adverse cardiac events at follow-up. This risk was similar in magnitude to that of other well-established clinical risk factors, and increased for proportionally greater procedural complexity; (

2) Compared with shorter DAPT, prolonged DAPT was associated with a significant anti-ischemic benefit in patients who underwent complex PCI; of note the magnitude of the anti-ischemic benefit of prolonged DAPT was proportionally greater per increase in procedural complexity;

(3) The benefits of prolonged DAPT appeared to be uniform across complex PCI components, DES generations, and clinical presentation.

MedicalResearch.com: What should readers take away from your report?

Response: Currently, clinical decision-making on upfront DAPT intensity and duration after coronary stenting are predominantly on the basis of clinical is chemic and bleeding risk factors.Our study suggest that procedural complexity is an important ischemic risk factor to take into account when tailoring upfront DAPT duration after coronary stenting with DES. This message is particularly important for the practicing interventional cardiologist at the time of upfront (immediately after the procedure) decision regarding DAPT duration. Current guidelines and available risk scores only take into account few of the potential variables that may influence future ischemic risk. In addition variables incorporated in these risk scores that predict ischemic risk do not necessarily imply that are going to be modified by DAPT (for example in diabetes mellitus the efficacy of DAPT may be attenuated due to impairments in clopidogrel pharmacokinetic). Conversely, procedural complexity, which may constitute an intuitive factor, besides clinical presentation, to tailor upfront decision on DAPT duration (3 or 6 versus 12 or more months). The greater benefits with prolonged DAPT who undergo complex PCI may be explained by the following:

(1) more and longer stents implanted imply the presence of additional potential sites of delayed metallic platform endothelialization, which may act as a trigger for platelet-mediated thrombosis;

(2) stenting of complex lesions may enhance the risk of stent malapposition, incomplete lesion coverage, residual edge dissection or impaired vascular healing which enhance the local predisposition to thrombosis;

(3) patients who undergo more complex PCI intrinsically have a greater extent of atherosclerosis, therefore they remain more prone to develop acute plaque changes beyond the stented vascular segments. Of note the benefit of longer DAPT was greater per increase in procedural complexity, underlying the substantial influence of more complex procedures on future ischemic risk.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: Future research in tailoring optimal platelet inhibition should explore the impact of new risk factors that predict ischemic or bleeding risk. For ischemic risk possibly a more tailored approach according biomarkers (such as CRP or troponin) and underlying coronary, carotid and peripheral arterial anatomy (such as plaque burden, thin cap fibroatheromas, necrotic core, etc) may be key in identify patients at really high risk for atherothrombosis.

For bleeding, the safety of DAPT intensity and duration should be explored across biomarkers and non-captured risk factors (such as malignancy, frailty or fall risk, hematological bleeding diathesis, or any other medical condition predisposing to clinically relevant bleeding).

MedicalResearch.com: Is there anything else you would like to add?

Response: Duration of DAPT has been a strong matter of debate. Currently the general consensus seem to be that optimal DAPT intensity and duration should be tailored according to the underlying ischemic and bleeding risk in order to provide net clinical benefit on an individual basis. This study possibly represent a step forward to better understand which patient should benefit of prolonged DAPT.

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.

Citation:

ESC Abstract: P4308
and JACC publication:

Authors:

G. Giustino1, A. Chieffo1, T. Palmerini2, M. Valgimigli3, F. Feres4, A. Abizaid4, M.K. Hong5, H.S. Kim5, M. Gilard6, M.C. Morice7, M.B. Leon8, D.L. Bhatt9, P. Genereux8, G.W. Stone8, A. Colombo8, 1University Vita-Salute San Raffaele, Cardiothoracic Department, Interventional Cardiology Unit – Milan – Italy, 2University of Bologna – Bologna – Italy, 3Bern University Hospital – Bern – Switzerland, 4Institute Dante Pazzanese of Cardiology – Sao Paulo – Brazil, 5Yonsei University College of Medicine – Seoul – Korea Republic of, 6University Hospital of Brest – Brest – France, 7Cardiovascular Institute Paris-Sud (ICPS) – Massy – France, 8Columbia University Medical Center – New York – United States of America, 9Brigham and Women’s Hospital – Boston – United States of America,
On behalf: DAPT trialists’ collaboration

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Last Updated on August 30, 2016 by Marie Benz MD FAAD