The duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) is a constantly evolving field. Trials have demonstrated non-inferiority for early de-escalation of DAPT therapy (Feres et al, 2013; Kim et al, 2020) with reduced bleeding, conversely, studies examining extended therapy have shown reduced major adverse cardiovascular events (MACE), and have thus generated much interest within the cardiology community (Bonaca et al, 2015; Mauri et al, 2014). It is evident that a personalised approach to antiplatelet choice and duration can improve patient outcomes.
Scoring systems, such as the DAPT score, have been developed to aid clinicians in risk stratification post PCI, and subsequently in DAPT duration decisions al, 2020). A recent meta-analysis demonstrated that a DAPT score >2 was associated with a higher risk of MACE; with an extended course of treatment (18-24 months) being associated with reduced risk in this cohort when compared to a 12-month duration (Witberg et al, 2020).
Method and results
Given the ever-increasing body of evidence and availability of scoring systems, the authors aimed to assess if the personalisation of DAPT was being translated into clinical practice. A single centre retrospective analysis of 400 patients who had undergone PCI between August 2017 and February 2018 was undertaken. The British Cardiovascular Intervention Society (BCIS), National PCI database and electronic patient notes were reviewed. Data collected included PCI indication, initial DAPT duration recommended, actual DAPT duration received and reasons for any alterations. Other variables included left ventricular function, and MACE, bleeding episodes or hospital admission within 24 months of the index procedure. Actual DAPT duration was also compared to recommended duration based on calculated DAPT scores. In combination with the DAPT score being used, therapy was considered personalised if individual patient factors had been taken under consideration when treatment length was decided.
The results of our analysis are displayed in Figure 1. There were 400 patients were included in the study, 25% were female (24.8%). Seven patients (1.8%) had documented evidence of an individualised approach to DAPT therapy. 316 patients were initially prescribed a DAPT duration of 12 months. There were 26 bleeding events in total; DAPT therapy was continued in 17 and shortened in 9 cases. When compared to calculated DAPT scores 46.8% had an appropriate therapy duration for their score. 43.8% may have benefited from a prolonged course and 9.4% from a shorter one.
Figure 1. Study results summarised (Tx = treatment, ACS = acute coronary syndrome)
Conclusion
This study identified infrequent personalisation of DAPT duration in clinical practice. There are many potential reasons for this. Firstly, the combination of high proportions of radial access, reduced complication rates and increasing volumes of PCI has resulted in a shorter length of stay in hospital, decreasing time for individualised therapy decisions to be considered (6). With increasing volumes of PCI there may also be demand for rapid patient turnaround in the catheterisation laboratory, resulting in less time available to complete detailed procedure reports and letters, or these tasks being delegated to junior team members. Secondly, the development of multiple ‘transfer and repatriate’ programs across the UK has allowed patients admitted in non-PCI centres to undergo timely PCI. However, this means interventional cardiologists may only meet patients briefly, with discharge decisions and follow-up then carried out locally by those less familiar with varied DAPT regimes (Banning et al, 2015). Additionally, there has been a move towards nurse-led post-PCI follow-up (Pottle et al, 2013). Whilst this has shown improved patient satisfaction with more time dedicated to addressing secondary risk factor management (Pottle et al, 2013), it may be that these practitioners have less confidence in reviewing or altering DAPT regimes. Finally, significant confusion exists amongst the interventional cardiology community with respect to the potential risks and benefits of varying DAPT duration, and thus many operators may simply avoid the question altogether (Valgimigli et al, 2015).
This study has several potential limitations. Firstly, this study was carried out in a single centre and as such results may not be generalisable to all centres. Secondly, as this study assessed PCI undertaken between 2017 and 2018 it is possible that familiarity with newer DAPT regimes has since increased. More contemporary, multi-centre work is required to assess if recently published work on this topic has altered the proportions of personalised therapy.
In conclusion, strategies are clearly needed to address the issues identified here. The addition of a DAPT duration risk score to procedure reports may act as an aide-memoire to those generating procedure reports, as well as assisting those reviewing patients after the procedure.