In this retrospective study, we evaluated the safety of ad-hoc PCI in clopidogrel-naïve patients who were treated with intravenous tirofiban followed by a 600-mg clopidogrel loading dose immediately after the PCI procedure. After adjusting for baseline differences, we found no significant differences in 30-day MACE between the use of clopidogrel ≥ 1 day prior to elective PCI compared with the use of tirofiban followed by a clopidogrel loading dose in clopidogrel-naïve patients undergoing ad-hoc PCI. In addition, there were so significant differences between the 2 groups in the secondary outcomes. These findings suggest that in clopidogrel-naïve patients, ad-hoc PCI shortly after administration of a single high-dose bolus of tirofiban followed by a 600-mg clopidogrel loading dose immediately after the PCI is safe and effective.

Over the past 2 decades, there has been a rise in the use of ad-hoc PCI, which can mainly be attributed to the efficacy of PCI for ACS and research indicating that ad-hoc PCI is a safe and effective option [9]. Possible advantages of ad-hoc PCI in clopidogrel-naïve patients with AP are reduction of the risk of access site-related complications, Furthermore, this strategy has proven to be cost-effective as it reduces the demand for materials, personnel and hospital capacity. Moreover, it is associated with greater patient-friendliness, as the patient is diagnosed and treated in one session [9].

Pretreatment with clopidogrel in all patients who undergo elective ICA may be safe. The PRAGUE-8 trial showed that a high loading dose of clopidogrel before elective ICA/PCI increased the risk of minor bleeding complications, while the benefit on periprocedural infarction was not significant [4]. The authors concluded that clopidogrel can be administered safely in the catheterisation laboratory. Furthermore, in patients undergoing elective or primary PCI, clopidogrel pretreatment is safe and effective [5].

Limited and ambiguous literature is available on the combination of a GPI bolus with subsequent P2Y12 inhibitor loading in the elective setting. The previously mentioned American and European guidelines do not agree on the use of a GPI in ad-hoc PCI [2, 3]. The European guidelines recommend using aspirin and clopidogrel as pretreatment for elective stenting procedures and UFH during PCI, whereas the American guideline states that in patients undergoing elective PCI who are treated with UFH and not pretreated with clopidogrel, it is reasonable to administer a GPI [2, 3]. Our results are in line with the recommendations of the American guidelines.

GPIs appear to reduce ischaemic events occurring after PCI in patients with ACS. The ischaemic benefit of GPI therapy has been attributed to its rapid onset of action and the > 80% platelet aggregation inhibition it induces in most patients [6]. Previous studies have shown the effectivity of GPIs in patients undergoing PCI [6]. In a post-hoc analysis, the relative efficacy and safety of ticagrelor versus clopidogrel in patients who did or did not receive a GPI in the PLATO trial were studied [5]. The authors found that the efficacy and safety of ticagrelor as compared with clopidogrel were not modified by GPI use according to the primary efficacy and safety endpoints. Other studies in the acute setting showed no significant effect of GPI use on outcomes with different anti-platelet strategies, including clopidogrel versus placebo [5].

Marian et al. studied the efficacy of crushed ticagrelor versus an eptifibatide bolus plus clopidogrel in 100 P2Y12 inhibitor-naïve, troponin-negative patients with ACS and found that the eptifibatide bolus plus clopidogrel led to faster and more potent platelet inhibition than ticagrelor and reduced periprocedural MI and injury [10].

Since this was a retrospective study, missing data could not be traced. Nonetheless, the study had enough power according to the calculated sample size. Furthermore, not all baseline characteristics were well balanced. Patients in group 2 were older, had a higher risk profile and had undergone more transfemoral procedures. Transfemoral access for performing coronary angiography may have a higher risk for bleeding complications [11]. In our study, we evaluated bleeding BARC ≥ 3; however, assessment of bleeding BARC 2 may at times also be important. Another limitation of our study is that we did not investigate the angiographic characteristics of the lesions.

Nevertheless, to reduce confounding bias, we performed Cox regression analysis. All patients who underwent elective invasive catheterisation were screened. The study sample can be considered representative of the population of patients undergoing PCI in daily practice. Performing ad-hoc PCI was at the discretion of the operator, while elective PCI was previously scheduled and usually discussed by the Heart Team. This may also have affected our findings. However, Cox regression analysis was performed to correct for important differences.

In the current study, clopidogrel-naïve patients were treated with a GPI bolus to bridge the duration action of clopidogrel. However, further research is needed to investigate the optimal pretreatment option for clopidogrel-naïve patients undergoing ad-hoc PCI, especially to analyse the safety of ad-hoc PCI in clopidogrel-naïve patients without GPI pretreatment or administration of a clopidogrel loading dose in the catheterisation laboratory immediately before or after the PCI.

This study may give an indication of the safety of GPI usage in the ad-hoc PCI setting in clopidogrel-naïve patients. Further study is necessary to determine the optimal antithrombotic therapy for ad-hoc PCI in clopidogrel-naïve patients.