The antithrombotic management of chronic coronary syndrome (CCS) involves a 6-month course of dual antiplatelet therapy (DAPT), followed by chronic aspirin therapy. In patients with a baseline indication for anticoagulation, a variable duration of triple antithrombotic therapy is administered, followed by dual antithrombotic therapy until the sixth month post-percutaneous coronary intervention (PCI), and ultimately a transition to chronic anticoagulation. However, advancements in stent technology reducing the risk of stent thrombosis and a growing focus on the impact of bleeding on prognosis have prompted the development of new therapeutic strategies. These strategies aim to enhance protection against ischemic events in the initial stages after PCI while mitigating the risk of bleeding in the long term. This article delineates the therapeutic strategies outlined in European and American guidelines for CCS management, with special attention to investigational strategies.

OBJECTIVE: The microvascular resistance reserve (MRR) is a novel invasive index of the microcirculation, which is independent of epicardial stenoses, and MRR has both diagnostic and prognostic implications. This study investigates whether MRR is associated with health status outcomes by revascularization in patients with moderate coronary stenoses.
METHODS: Consecutive patients with stable chest pain and moderate (30-90% diameter) stenoses on invasive coronary angiography (n=222) underwent invasive physiology assessment. Revascularization was performed by guideline recommendations. At baseline and follow-up, health status and myocardial perfusion were assessed by Seattle Angina Questionnaire (SAQ) and positron emission tomography. The primary endpoint was freedom from angina at follow-up with secondary endpoints including changes in health status by SAQ domains and myocardial perfusion by MRR and revascularization status. Low MRR was defined as ≤3.0.
RESULTS: Freedom from angina occurred in 38/173 patients. In multivariate analyses, MRR was associated with freedom from angina at follow-up (odds ratio 0.860, 95% confidence interval 0.740-0.987). By MRR and revascularization groups, patients with normal MRR who did not undergo revascularization, and patients with abnormal MRR who underwent revascularization, improved health status of angina frequency (mean difference SAQ angina frequency score 8.5 [3.07-13.11] and 13.5 [2.82-23.16], respectively). For both groups, health status of physical limitation (mean difference in SAQ physical limitation score 9.7 [4.79-11.93] and 8.7 [0.53-13.88], respectively) and general health status (mean difference in SAQ summary score 9.3 [5.18-12.50] and 10.8 [2.51-17.28], respectively) also improved. Only patients with abnormal MRR who underwent revascularization improved myocardial perfusion.
CONCLUSIONS: In patients with moderate coronary stenoses, MRR seems to predict symptomatic and perfusion benefit of revascularization.

OBJECTIVE: Overtesting of low-risk patients with suspect chronic coronary syndrome (CCS) is widespread. The acoustic-based coronary artery disease (CAD) score has superior rule-out capabilities when added to pre-test probability (PTP). FILTER-SCAD tested whether providing a CAD score and PTP to cardiologists was superior to PTP alone in limiting testing.
METHODS: At six Danish and Swedish outpatient clinics, patients with suspected new-onset CCS were randomised to either standard diagnostic examination (SDE) with PTP, or SDE plus CAD score, and cardiologists provided with corresponding recommended diagnostic flowcharts. The primary endpoint was cumulative number of diagnostic tests at one year and key safety endpoint major adverse cardiac events (MACE).
RESULTS: In total 2008 patients (46% male, median age 63 years) were randomised from October 2019 to September 2022. When randomised to CAD score (n=1002), it was successfully measured in 94.5%. Overall, 13.5% had PTP ≤5%, and 39.5% had CAD score ≤20. Testing was deferred in 22% with no differences in diagnostic tests between groups (p for superiority =0.56). In the PTP ≤5% subgroup, the proportion with deferred testing increased from 28% to 52% (p<0.001). Overall MACE was 2.4 per 100 person-years. Non-inferiority regarding safety was established, absolute risk difference 0.4% (95% CI -1.85 to 1.06) (p for non-inferiority = 0.005). No differences were seen in angina-related health status or quality of life.
CONCLUSIONS: The implementation strategy of providing cardiologists with a CAD score alongside SDE did not reduce testing overall but indicated a possible role in patients with low CCS likelihood. Further strategies are warranted to address resistance to modifying diagnostic pathways in this patient population.

OBJECTIVE: It has been reported that patients without standard modifiable cardiovascular (CV) risk factors (SMuRFs-diabetes, dyslipidaemia, hypertension, and smoking) presenting with first myocardial infarction (MI), especially women, have a higher in-hospital mortality than patients with risk factors, and possibly a lower long-term risk provided they survive the post-infarct period. This study aims to explore the long-term outcomes of SMuRF-less patients with stable coronary artery disease (CAD).
METHODS: CLARIFY is an observational cohort of 32 703 outpatients with stable CAD enrolled between 2009 and 2010 in 45 countries. The baseline characteristics and clinical outcomes of patients with and without SMuRFs were compared. The primary outcome was a composite of 5-year CV death or non-fatal MI. Secondary outcomes were 5-year all-cause mortality and major adverse cardiovascular events (MACE-CV death, non-fatal MI, or non-fatal stroke).
RESULTS: Among 22 132 patients with complete risk factor and outcome information, 977 (4.4%) were SMuRF-less. Age, sex, and time since CAD diagnosis were similar across groups. SMuRF-less patients had a lower 5-year rate of CV death or non-fatal MI (5.43% [95% CI 4.08-7.19] vs. 7.68% [95% CI 7.30-8.08], P = 0.012), all-cause mortality, and MACE. Similar results were found after adjustments. Clinical event rates increased steadily with the number of SMuRFs. The benefit of SMuRF-less status was particularly pronounced in women.
CONCLUSIONS: SMuRF-less patients with stable CAD have a substantial but significantly lower 5-year rate of CV death or non-fatal MI than patients with risk factors. The risk of CV outcomes increases steadily with the number of risk factors.

BACKGROUND: Guidelines and international appropriate use criteria increasingly endorse non-invasive stress testing to evaluate patients with suspected chronic coronary disease (CCD). We sought to review the real-world utilisation of non-invasive stress testing and investigate whether their use prior to PCI associates with outcomes in patients with CCD.
METHODS: Consecutive patients from a multicentre registry who underwent PCI for CCD between 2006 and 2018 were included. Clinical characteristics and outcomes were stratified according to whether stress testing was performed prior to PCI (stress vs no-stress groups). The primary outcome was 3-year all-cause mortality.
RESULTS: Among the 8251 patients included, 4970 (60.2 %) underwent pre-PCI stress testing and this proportion increased over time (p-for-trend<0.001). The stress group had a lower prevalence of prior revascularization, myocardial infarction, or heart failure, and a lower incidence of triple vessel disease, in stent re-stenosis, and ACC/AHA class B2/C lesions (all p < 0.001). When comparing post-procedural outcomes, the stress group had lower rates of arrhythmia (1.5 % vs 2.6 %, p = 0.001), new heart failure (0.2 % vs 0.8 %, p = 0.001), renal impairment, and a shorter length of stay (1.6 vs 2.1 days, p < 0.001). Mortality at 3-years was lower in those undergoing PCI following stress testing (5.8 % vs 8.8 %, p < 0.001). After adjusting for key clinical variables, stress guided revascularization was associated with a significantly lower risk of 3-year mortality (adjusted Hazard Ratio 0.77, 95 % CI 0.64-0.92).
CONCLUSIONS: In patients with CCD, PCI guided by non-invasive stress testing is increasingly utilized and associated with improved survival. Further studies are necessary to investigate whether this results from differences in patient characteristics, optimized patient selection, or refined choice of target vessel.

BACKGROUND: The optimal duration of dual antiplatelet therapy after currently available drug-eluting stent (DES) implantation to prevent stent thrombosis (ST) remains controversial. Delayed healing is frequently identified as a leading cause of ST in the early phase. However, a thorough pathological investigation into strut coverage after currently available DES implantation is lacking-a gap addressed in the current study.
METHODS: From our autopsy registry of 199 stented lesions, 4,713 struts from 66 currently available DES-stented lesions with an implant duration ≤370 days were histologically evaluated. Endothelial coverage was defined as the presence of luminal endothelial cells overlying struts and an underlying smooth muscle cell layer. The stented lesions were classified into acute coronary syndrome (ACS) (n = 40) and chronic coronary syndrome (CCS) (n = 26) groups and were compared. Endothelial coverage predictors were identified through logistic analysis.
RESULTS: Although ACS and CCS lesions presented comparable clinical characteristics, including age, sex, and cause of death, the latter exhibited a significantly higher prevalence of chronic kidney disease and hemodialysis than the former (33.3% vs. 65.2%; P = .02, 7.7% vs. 30.4%; P = .02). The poststent implant median duration was significantly shorter in ACS lesions than in CCS lesions (13 [IQR 5-26 days] vs. 40 [IQR 16-233 days]; P < .01). The endothelial coverage percentage was 3.5% at 30 days and 27.7% at 90 days after currently available DES implantation. Multivariable logistic regression analysis implicated implant duration of ≤90 days (odds ratio [OR], 0.009; 95% confidence interval [CI], 0.006-0.012; P < .01), superficial calcification (OR, 0.11; 95% CI, 0.07-0.17; P < .01), ACS culprit site (OR, 0.29; 95% CI, 0.09-0.94; P = .039), and circumferentially durable polymer-coated DES (OR, 0.32; 95% CI, 0.24-0.41; P < .01) as delayed endothelial coverage predictors.
CONCLUSIONS: Endothelial coverage was limited at 90 days after currently available DES implantation, and the ACS culprit site and circumferentially durable polymer-coated DES were identified as independent predictors of delayed endothelial coverage. Our findings suggest the importance of underlying plaque morphology and stent technology for vessel healing after such implantation.

The prognostic relevance of periprocedural myocardial infarction (PMI) in patients with chronic coronary syndrome undergoing percutaneous coronary intervention (PCI) is still matter of debate, particularly regarding the type (cardiac troponin or creatin kinase-MB) and different thresholds of biomarkers elevation, as the importance of associated ancillary criteria of ischemia or concomitant angiographic complications. There are still uncertainties regarding the value of PMI as event which is prognostically equivalent to spontaneous myocardial infarction or if it simply represents a marker of baseline risk, atherosclerotic burden and procedural complexity. In the present review, we will present the mechanisms and predictors of PMI occurring during PCI and potential treatment strategies to reduce its occurrence. We will also overview all commonly adopted definitions of PMI, which carry different prevalence and prognostic implications in daily practice and clinical trials. Finally, we will discuss the impact of different PMI definitions on the interpretation of trials results, emphasizing the importance of adequate endpoints selection in the planning and interpretation of clinical trials.

Acute coronary syndrome (ACS) is a leading cause of mortality worldwide. Despite optimal antiplatelet therapy recommendation after ischemic events, recurrent thrombotic complications rate remains high. The recurrent events maybe in part due to increased thrombin levels during ACS which may underscore the need for an additional anticoagulation therapy. Given the advantages of non-vitamin K antagonist oral anticoagulants (NOACs) over warfarin, they have the potential to prevent thrombus formation, in the presence or absence of atrial fibrillation, but at the cost of increased risk of bleeding. NOACs have also shown a promising efficacy in managing left ventricular thrombus and a potential benefit in avoiding stent thrombosis after percutaneous coronary revascularization. Taken as a whole, NOACs are increasingly used for off-licence indications, and continue to evolve as essential therapy in preventing and treating thrombotic events. Herein, this review discusses NOACs off-label indications in the setting of ischemic coronary disease.

Following percutaneous coronary intervention (PCI), an initial course of dual antiplatelet therapy (DAPT) with aspirin and a P2Y 12 inhibitor ( P2Y 12 -i) is recommended to minimize the risk of thrombotic complications. After the initial period of DAPT, antiplatelet monotherapy, usually consisting of aspirin, is administered for long-term secondary prevention. However, over the last few years there has been accruing evidence on P2Y 12 -i monotherapy, both in the acute (i.e., post-PCI; after a brief period of DAPT, transitioning to monotherapy before six or 12 months in patients with chronic or acute coronary syndrome, respectively) and chronic (i.e., long-term secondary prevention; after completion of six or 12 months of DAPT, in patients with chronic or acute coronary syndrome, respectively) settings. In aggregate, most studies of short DAPT with transition to P2Y 12 -i monotherapy showed a reduced risk of bleeding complications, without any significant increase in ischemic events as compared to standard DAPT. On the other hand, the evidence on long-term P2Y 12 -i monotherapy is scarce, but results from a randomized trial showed that clopidogrel monotherapy outperformed aspirin monotherapy in terms of net benefit, ischemic events and bleeding. Antiplatelet therapy is also recommended for patients undergoing PCI and with an established indication for long-term oral anticoagulation (OAC). In this scenario, a brief period of triple therapy (i.e., aspirin, P2Y 12 -i and OAC) is followed by a course of dual antithrombotic therapy (usually with P2Y 12 -i and OAC) and ultimately by lifelong OAC alone. European and American guidelines have been recently updated to provide new recommendations on antithrombotic therapy, including the endorsement of P2Y 12 -i monotherapy in different settings. However, some areas of uncertainty still remain and further randomized investigations are ongoing to fulfil current gaps in knowledge. In this review, we assess the current knowledge and evidence on P2Y 12 -i monotherapy for the early and long-term secondary prevention in patients undergoing PCI, and explore upcoming research and future directions in the field.

BACKGROUND: This study aimed to describe the status of antithrombotic therapy at discharge and prognosis in patients with atrial fibrillation (AF) and chronic coronary syndrome (CCS) who underwent percutaneous coronary intervention (PCI).
METHODS: This was an observational, prospective study. The primary endpoint was major adverse cardiovascular events (MACE), including all-cause death, myocardial infarction, stroke/transient ischemic attach (TIA), systemic embolism or ischemia-driven revascularization. Bleeding events were collected according to the Thrombolysis in Myocardial Infarction (TIMI) criteria.
RESULTS: Between 2017 and 2019, a cohort of 516 patients (mean age 66, [SD 9], of whom 18.4% were female) with AF and CCS who underwent PCI were evaluated, with a median followed-up time of 36 months (Interquartile range: 22-45). MACE events occurred in 13.0% of the patients, while the TIMI bleeding events were observed in 17.4%. Utilization of TAT (triple antithrombotic therapy) (P < 0.001) and oral anticoagulation (OAC) therapy (P < 0.001) increased through years. History of heart failure (HF) (Hazard ratio [HR], 1.744; 95% confidence interval [CI], 1.011-3.038) and TAT (HR, 2.708; 95%CI, 1.653-4.436) had independent associations with MACE events. OAC (HR, 10.378; 95%CI, 6.136-17.555) was identified as a risk factor for bleeding events. A higher creatine clearance (HR, 0.986; 95%CI, 0.974-0.997) was associated with a lower incidence of bleeding events.
CONCLUSIONS: Antithrombotic therapy has been improved among patients with AF and CCS who underwent PCI these years. History of HF and TAT were independently associated with MACE events. Higher creatine clearance was protective factor of bleeding events, while OAC was a risk factor for TIMI bleeding events.