Authors' objectives: The Swiss Federal Department of Home Affairs commissioned the Federal Office of Public health (FOPH) to evaluate the evidence pertaining to the comparative clinical efficacy and safety of six to 12 months dual antiplatelet therapy (DAPT) versus extended DAPT (>12 months), following percutaneous coronary intervention (PCI) with stent insertion in coronary artery disease (CAD) patients and various subpopulations. To address this question the FOPH summarised the findings of a recent health technology assessment (HTA) report published by the Canadian Agency for Drugs and Technologies in Health that addressed the same research question. An additional research question in the Canadian report regarded an economic evaluation of the two treatment variants. A short summary of the economic analysis is also presented, be it without contextualisation of the findings in the Swiss clinical practice and reimbursement environment.

Authors' results and conclusions: Clinical Findings Extending DAPT beyond 12 months after PCI was shown to be associated with a reduced risk of myocardial infarction (MI) and of probable and definite stent thrombosis in CAD patients, when compared with standard-duration DAPT (six to 12 months). At the same time, extending DAPT beyond 12 months was associated with an increased risk of bleeding. No significant differences were found in the risk of all-cause or cardiovascular death, stroke, urgent target revascularisation, major adverse cardiovascular and cerebrovascular event, or gastrointestinal bleeding between extended DAPT and standard-duration DAPT. Within the CAD patient population, patients with a previous MI, acute coronary syndrome, no diabetes or those younger than 75 years seemed to benefit the most from extending DAPT beyond 12 months following PCI with stenting. Economic Evaluation From an economic perspective extending DAPT beyond the initial six to 12 months after PCI showed to be slightly dominant with a small incremental benefit of 0.0160 quality of life years (QALY) and small savings of 707 Canadian dollars. However, the vast majority of the modest benefit was accrued in the post-extended DAPT phase of the model. These findings should be interpreted with caution given the high degree of uncertainty of the data during this post-extended phase. Discussion The CADTH HTA was conducted according to standardised procedures in a sound and reproducible manner. The clinical findings were extracted from a large body of evidence of primarily high quality. The patient selection criteria applied in the trials excluded all patients with increased bleeding risk and those with increased risk of ischaemic events. This preselection of CAD patients should be considered when extrapolating the findings to the daily practice situation. In fact, patients with increased risk of ischaemic events may benefit the most from extended DAPT. Further research focussed on this patient population may facilitate defining definitive patient selection criteria for extended DAPT beyond 12 months. CAD patients selected for the trials received a BMS or a first-, second- or third-generation DES. Subgroup analyses distinguishing bare metal stent- and drug-eluting stent-treated patients were conducted. However, no subgroup analyses were conducted distinguishing first-, second- and third-generation DES-treated patients. This is a limitation of the Canadian report as the adverse event rates associated with the type of DES stent have decreased as stent technology evolved. Conclusion Extending DAPT duration beyond the in Switzerland common six to 12 months DAPT was shown to benefit a selected group of CAD patients after PCI. This prolongation of DAPT may prevent serious complications such as MI and stent thrombosis. Unrestricted reimbursement of DAPT for these patients seems to be justified from a clinical perspective. From a health economic perspective, extending DAPT beyond 12 months may prove to be cost-effective through prevention of serious cardiovascular and cerebrovascular events. Prior to evaluating the economic effect of these events in selected patients in Switzerland, follow-up studies are needed to evaluate the occurrence of such severe events in the post-extended DAPT phase.

Project Status: Completed

URL for project: https://www.bag.admin.ch/bag/en/home/versicherungen/krankenversicherung/krankenversicherung-leistungen-tarife/hta/hta-projekte/dualeantithrombozytaeretherapie.html

Year Published: 2020

URL for published report: https://www.bag.admin.ch/dam/bag/en/dokumente/kuv-leistungen/leistungen-und-tarife/hta/berichte/h0008dual-hta-shortreport.pdf.download.pdf/h0008dual-hta-shortreport.pdf

URL for additional information: https://www.bag.admin.ch/bag/en/home/versicherungen/krankenversicherung/krankenversicherung-leistungen-tarife/hta/hta-programm.html

English language abstract: An English language summary is available

Publication Type: Rapid Review

Country: Switzerland

Organisation Name: Swiss Federal Office of Public Health (FOPH)

Contact Address: Federal Office of Public Health, Schwarzenburgstrasse 157, CH-3003 Berne, Switzerland

Contact Name: Stephanie Vollenweider

Contact Email: hta@bag.admin.ch

Copyright: Swiss Federal Office of Public Health