Should We Use Aspirin or P2Y12 Inhibitor Monotherapy in Stable Ischemic Heart Disease?

PURPOSE OF REVIEW: To summarize the recent evidence and guideline recommendations on aspirin or P2Y12 inhibitor monotherapy in patients with stable ischemic heart disease and provide insights into future directions on this topic, which involves transition to a personalized assessment of bleeding and thrombotic risks. RECENT FINDINGS: It has been questioned whether the evidence for aspirin as the foundational component of secondary prevention in patients with coronary artery disease aligns with contemporary pharmaco-invasive strategies. The recent HOST-EXAM study randomized patients who had received dual antiplatelet therapy for 6 to 18 months without ischemic or major bleeding events to either clopidogrel or aspirin for a further 24 months, and demonstrated that the patients in the clopidogrel arm had significantly lower rates of both thrombotic and bleeding complications compared to those in the aspirin arm. The patient-level PANTHER meta-analysis showed that in patients with established coronary artery disease, P2Y12 inhibitor monotherapy was associated with lower rates of myocardial infarction, stent thrombosis as well as gastrointestinal bleeding and hemorrhagic stroke compared to aspirin monotherapy, albeit with similar rates of all-cause mortality, cardiovascular mortality and major bleeding. Long-term low-dose aspirin is recommended for secondary prevention in patients with stable ischemic heart disease, with clopidogrel monotherapy being acknowledged as a feasible alternative. Dual antiplatelet therapy for six months after percutaneous coronary intervention remains the standard recommendation for patients with stable ischemic heart disease. However, the duration of dual antiplatelet therapy may be shortened and followed by P2Y12 inhibitor monotherapy or prolonged based on individualized evaluation of the patient's risk profile.

Aspirin-free P2Y12 inhibitor monotherapy immediately after percutaneous coronary intervention: A systematic review.

Background: A modified antiplatelet therapy approach after percutaneous coronary intervention (PCI), specifically reducing dual antiplatelet therapy (DAPT) duration and transitioning to P2Y12 inhibitor monotherapy, may offer advantages in terms of bleeding risk reduction. However, the impact of initiating aspirin-free P2Y12 inhibitor monotherapy immediately after PCI is not yet fully understood. Methods: We systematically searched the PubMed and Embase databases until January 2024 for studies that examined the use of P2Y12 inhibitor monotherapy as a treatment approach without initial DAPT following PCI. Results: Four single-arm pilot prospective studies and 1 randomized controlled trial were included. In acute coronary syndrome patients with P2Y12 monotherapy following aspirin withdrawal immediately after PCI, the occurrence rates of the primary ischemic and bleeding endpoint were 2.91 % (8 out of 275 patients) and 1.09 % (3 out of 275 patients) respectively, whereas both the incidence rates of the primary ischemic and bleeding endpoints were 0.25 % (1 out of 407 patients) in individuals with stable coronary artery disease. In the STOPDAPT-3 trial comparing the effect of aspirin-free prasugrel monotherapy with standard DAPT after PCI, no differences were found in the primary ischemic or bleeding endpoints and most secondary outcomes (death, stroke, and myocardial infarction). However, there was an increased risk of coronary revascularization and stent thrombosis in the no-aspirin group. Conclusions: Single-arm studies suggest the safety and feasibility of aspirin-free P2Y12 inhibitor monotherapy without initial DAPT after PCI in selected patients with acute coronary syndrome or stable coronary artery disease. However, the safety and efficacy of this aspirin-free approach compared with standard DAPT strategies following PCI still require further investigation.

Aspirin versus Clopidogrel Monotherapy After Percutaneous Coronary Intervention: 1-Year Follow-up of the STOPDAPT-3 Trial.

BACKGROUND AND AIMS: There was no previous trial comparing aspirin monotherapy with a P2Y12 inhibitor monotherapy following short dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) with drug-eluting stents (DES). METHODS: In the STOPDAPT-3, patients with acute coronary syndrome (ACS) or high bleeding risk (HBR) were randomly assigned to either 1-month DAPT with aspirin and prasugrel followed by aspirin monotherapy (aspirin group) or 1-month prasugrel monotherapy followed by clopidogrel monotherapy (clopidogrel group). This secondary analysis compared aspirin monotherapy with clopidogrel monotherapy by the 30-day landmark analysis. The co-primary endpoints were the cardiovascular endpoint defined as a composite of cardiovascular death, myocardial infarction, definite stent thrombosis, or ischaemic stroke, and the bleeding endpoint defined as Bleeding Academic Research Consortium 3 or 5. RESULTS: Of 6002 assigned patients, 5833 patients (aspirin group: N = 2920 and clopidogrel group: N = 2913) were included in the 30-day landmark analysis. Median age was 73 (interquartile range 64-80) years, women 23.4%, ACS 74.6%, and HBR 54.1%. The assigned monotherapy was continued at 1 year in 87.5% and 87.2% in the aspirin and clopidogrel groups, respectively. The incidence rates beyond 30 days and up to 1 year were similar between the aspirin and clopidogrel groups for both cardiovascular endpoint (4.5 and 4.5 per 100 person-year, hazard ratio [HR] 1.00 [95% confidence interval (CI) 0.77-1.30], P = .97), and bleeding endpoint (2.0 and 1.9, HR 1.02 [95% CI 0.69-1.52], P = .92). CONCLUSIONS: Aspirin monotherapy compared to clopidogrel monotherapy was associated with similar cardiovascular and bleeding outcomes beyond 1 month and up to 1 year after PCI with DES.

Risk of Bleeding Among Cangrelor-Treated Patients Administered Upstream P2Y12 Inhibitor Therapy: The CAMEO Registry.

Background: Little is known about the bleeding risk associated with cangrelor use in patients with myocardial infarction (MI) who are exposed to an oral P2Y12 inhibitor before coronary angiography. Methods: Cangrelor in Acute MI: Effectiveness and Outcomes (CAMEO) is an observational registry studying platelet inhibition for patients with MI. Upstream oral P2Y12 inhibition was defined as receipt of an oral P2Y12 inhibitor within 24 hours before hospitalization or in-hospital before angiography. Among cangrelor-treated patients, we compared bleeding after cangrelor use through 7 days postdischarge between patients with and without upstream oral P2Y12 inhibitor exposure. Results: Among 1802 cangrelor-treated patients with MI, 385 (21.4%) received upstream oral P2Y12 inhibitor treatment. Of these, 101 patients (33.8%) started cangrelor within 1 hour, 103 (34.4%) between 1 and 3 hours, and 95 (31.8%), >3 hours after in-hospital oral P2Y12 inhibitor administration; the remaining received an oral P2Y12 inhibitor before hospitalization. There was no statistically significant difference in rates of bleeding among cangrelor-treated patients with and without upstream oral P2Y12 inhibitor exposure (6.5% vs 8.8%; adjusted odds ratio [OR], 0.62; 95% CI, 0.38-1.01). Bleeding was observed in 5.0%, 10.7%, and 3.2% of patients treated with cangrelor <1, 1 to 3, and >3 hours after the last oral PY12 inhibitor dose, respectively; bleeding rates were not statistically different between groups (1-3 hours vs <1 hour: adjusted OR, 2.70; 95% CI, 0.87-8.32; >3 hours vs <1 hour: adjusted OR, 0.65; 95% CI, 0.15-2.85). Conclusions: Bleeding risk was not observed to be significantly higher after cangrelor treatment in patients with and without upstream oral P2Y12 inhibitor exposure.

Effect of Ticagrelor Versus Clopidogrel After Off-Pump Coronary Artery Bypass Grafting on Postoperative Atrial Fibrillation: A Cohort Study.

BACKGROUND: This study aimed to explore the effect of a P2Y12 inhibitor regimen on the occurrence of postoperative atrial fibrillation (POAF) after off-pump coronary artery bypass graft surgery in carriers with the cytochrome P450 family 2 subfamily C member19 loss-of-function allele. METHODS AND RESULTS: From May 2019 to November 2023, patients containing the cytochrome P450 family 2 subfamily C member19*2 or *3 allele undergoing elective first-time off-pump coronary artery bypass graft surgery including aspirin 100 mg/d and ticagrelor 180 mg/d (AT group; n=95) versus clopidogrel 75 mg/d (aspirin and clopidogrel group; n=95) were prospectively followed. The primary end point was the cumulative incidence of POAF in a week. The secondary end points were POAF burden, platelet aggregability, systemic immune-inflammation index and heart rate variability. The incidence of POAF was 21.1% in the AT group versus 41.1% in the aspirin and clopidogrel group (hazard ratio, 0.46 [95% CI, 0.27-0.76]; P=0.003). POAF burden, ADP-induced platelet aggregation and systemic immune-inflammation index was notably lower in the AT group than the aspirin and clopidogrel group. Heart rate variability data showed an increase in both high-frequency and SD of normal-to-normal RR intervals in the AT group with a decreased low-frequency/high-frequency ratio, suggesting that the sympathetic/parasympathetic activation was balanced. CONCLUSIONS: In patients carrying the cytochrome P450 family 2 subfamily C member19 loss-of-function allele, an AT regimen after off-pump coronary artery bypass grafting was associated with a lower incidence of POAF, paralleled by lower atrial fibrillation burden, ADP-induced platelet aggregation, lower systemic immune-inflammation index reaction, and a balanced automatic nerve system compared with an aspirin and clopidogrel regimen. Inhibiting the systemic immune-inflammation response and sustaining automatic nerve balance may underlie the therapeutic effect of POAF by a potent antiplatelet combination.

P2Y12 Receptor Inhibitor for Antiaggregant Therapies: From Molecular Pathway to Clinical Application.

Platelets play a significant role in hemostasis, forming plugs at sites of vascular injury to limit blood loss. However, if platelet activation is not controlled, it can lead to thrombotic events, such as myocardial infarction and stroke. To prevent this, antiplatelet agents are used in clinical settings to limit platelet activation in patients at risk of arterial thrombotic events. However, their use can be associated with a significant risk of bleeding. An enhanced comprehension of platelet signaling mechanisms should facilitate the identification of safer targets for antiplatelet therapy. Over the past decade, our comprehension of the breadth and intricacy of signaling pathways that orchestrate platelet activation has expanded exponentially. Several recent studies have provided further insight into the regulation of platelet signaling events and identified novel targets against which to develop novel antiplatelet agents. Antiplatelet drugs are essential in managing atherothrombotic vascular disease. The current antiplatelet therapy in clinical practice is limited in terms of safety and efficacy. Novel compounds have been developed in response to patient variability and resistance to aspirin and/or clopidogrel. Recent studies based on randomized controlled trials and systematic reviews have definitively demonstrated the role of antiplatelet therapy in reducing the risk of cardiovascular events. Antiplatelet therapy is the recommended course of action for patients with established atherosclerosis. These studies compared monotherapy with a P2Y12 inhibitor versus aspirin for secondary prevention. However, in patients undergoing percutaneous coronary intervention, it is still unclear whether the efficacy of P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy depends on the type of P2Y12 inhibitor. This paper focuses on the advanced-stage evaluation of several promising antiplatelet drugs.

P2Y12 Inhibitor Monotherapy After Short DAPT in Acute Coronary Syndrome: A Systematic Review and Meta-analysis.

BACKGROUND: P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy (DAPT) may balance ischemic and bleeding risks in patients with acute coronary syndrome (ACS). However, it remains uncertain how different P2Y12 inhibitors used as monotherapy affect outcomes. METHODS: Randomized controlled trials comparing P2Y12 inhibitor monotherapy after a short course of DAPT (≤3 months) versus 12-month DAPT in ACS were included. The primary endpoint was major adverse cardiovascular events (MACE). All analyses included an interaction term for the P2Y12 inhibitor used as monotherapy. Trial sequential analysis were run to explore whether the effect estimate of each outcomes may be affected by further studies. RESULTS: Seven trials encompassing 27,284 ACS patients were included. Compared with 12-month DAPT, P2Y12 inhibitor monotherapy after a short course of DAPT was associated with no difference in MACE (OR 0.92, 95% CI 0.76-1.12) and a significant reduction in net adverse clinical events (NACE) (OR 0.75; 95% CI 0.60-0.94), any bleeding (OR 0.54, 95% CI 0.43-0.66) and major bleeding (OR 0.47, 95% CI 0.37-0.60). Significant interactions for subgroup difference between ticagrelor and clopidogrel monotherapy were found for MACE (pint=0.016), all-cause death (pint=0.042), NACE (pint=0.018), and myocardial infarction (pint=0.028). Trial sequential analysis showed conclusive evidence of improved NACE with ticagrelor, but not with clopidogrel monotherapy, compared with standard DAPT. CONCLUSIONS: In patients with ACS, P2Y12 inhibitor monotherapy after short DAPT halves bleeding without increasing ischemic events compared with standard DAPT. Ticagrelor, but not clopidogrel monotherapy, reduced MACE, NACE and mortality compared with standard DAPT, supporting its use after aspirin discontinuation. Protocol registration: This study is registered in PROSPERO (CRD42023494797).

P2Y12 Inhibitor Monotherapy After Short-Term Dual Antiplatelet Therapy in Acute Coronary Syndrome.

Recent studies have shown similar safety and efficacy of short-term dual antiplatelet therapy (DAPT) followed by P2Y12 inhibitor (P2Y12i) monotherapy when compared with standard DAPT. However, the optimal DAPT duration and regimen in acute coronary syndrome (ACS) patients who underwent percutaneous coronary intervention is still unclear. Online databases were searched for randomized controlled trials evaluating P2Y12i monotherapy after short DAPT (≤3 months) versus standard DAPT (≥12 months) in ACS patients. The outcomes of interest were all-cause death, cardiovascular death, myocardial infarction, stent thrombosis, target-vessel revascularization, and major bleeding. Random-effects model was used to calculate pooled odds ratios (OR) and 95% confidence intervals (CI). Six randomized controlled trials with a total of 23,884 patients (n = 11,904 P2Y12i monotherapy, n = 11,980 standard DAPT) were included. Compared with standard DAPT, P2Y12i monotherapy after short DAPT was associated with similar odds of all-cause death (OR 0.86, 95% CI 0.65 to 1.12, p = 0.26) and cardiovascular death (OR 0.75, 95% CI 0.43 to 1.29, p = 0.29) at 1 year. Similarly, there were no significant differences in rates of myocardial infarction (OR 1.09, 0.83 to 1.43, p = 0.53), stent thrombosis (OR 1.09, 95% CI 0.71 to 1.67, p = 0.70) and target-vessel revascularization (OR 0.81, 95% CI 0.65 to 1.01, p = 0.07) between the P2Y12i monotherapy and standard DAPT arms. The P2Y12i monotherapy group had significantly lower major bleeding (OR 0.49, 95% CI 0.38 to 0.64, p < 0.001) when compared with standard DAPT. In conclusion, in patients with ACS who underwent percutaneous coronary intervention, P2Y12i monotherapy after short DAPT significantly reduces bleeding without increasing ischemic risk when compared with standard DAPT therapy.

Comprehensive comparative efficacy and safety of potent P2Y12 inhibitors in patients undergoing coronary intervention: A systematic review and meta-analysis.

Potent P2Y12 receptor antagonists have been used widely for patients undergoing percutaneous coronary intervention with different results. Benefits from different regimens various between trials. Randomized controlled trials (RCTs) have restrictive inclusion and exclusion criteria; thus, they may limit the generalizability of the findings to a broader population. This study was aimed to comprehensively investigate the outcomes of potent P2Y12 inhibitors in patients undergoing PCI, including RCTs and real-world evidence (RWE) studies. Multiple electronic databases were systemically reviewed and searched on compared potent P2Y12 inhibitors with clopidogrel. The primary efficacy end point was composite ischemic cardiovascular event and primary safety endpoint was major bleeding. Overall estimates of proportions and incidence rates with 95 % confidence intervals (CI) were calculated using fixed-effects models. Total 24 studies (140,986 patients) underwent coronary intervention were included in this meta-analysis, including 18 RCTs and 6 large cohort studies with propensity score matching. The potent P2Y12 inhibitors including cangrelor, prasugrel, and ticagrelor, significantly decreased the risk of composite adverse cardiovascular ischemic events (95 % CI 0.89-0.96, p < 0.001), but increased major bleeding (95 % CI 1.15-1.33, p < 0.001) or any bleeding (95 % CI 1.21-1.33, p < 0.001) compared with Clopidogrel. This meta-analysis merges RCTs and RWE studies and comprehensively evidences newer potent P2Y12 inhibitors are significantly more effective than clopidogrel in reduction of composite adverse thrombotic events, but the incidence of major or any bleeding was higher compared with clopidogrel.

Ticagrelor or prasugrel vs. clopidogrel in patients with atrial fibrillation undergoing percutaneous coronary intervention for myocardial infarction.

Aims: The efficacy and safety of ticagrelor or prasugrel vs. clopidogrel in patients with atrial fibrillation (AF) on oral anticoagulation (OAC) undergoing percutaneous coronary intervention (PCI) for myocardial infarction (MI) have not been established. Methods and results: This was a nationwide cohort study of patients on OAC for AF who underwent PCI for MI from 2011 through 2019 and were prescribed a P2Y12 inhibitor at discharge. The primary efficacy outcome was major adverse cardiovascular events (MACE), defined as a composite of death from any cause, stroke, recurrent MI, or repeat revascularization. The primary safety outcome was cerebral, gastrointestinal, or urogenital bleeding requiring hospitalization. Absolute and relative risks for outcomes at 1 year were calculated through multivariable logistic regression with average treatment effect modelling. Outcomes were standardized for the individual components of the CHA2DS2-VASc and HAS-BLED scores as well as type of OAC, aspirin, and proton pump inhibitor use. We included 2259 patients of whom 1918 (84.9%) were prescribed clopidogrel and 341 (15.1%) ticagrelor or prasugrel. The standardized risk of MACE was significantly lower in the ticagrelor or prasugrel group compared with the clopidogrel group (standardized absolute risk, 16.3% vs. 19.4%; relative risk, 0.84, 95% confidence interval, 0.70-0.98; P = 0.02), while the risk of bleeding did not differ (standardized absolute risk, 5.5% vs. 5.1%; relative risk, 1.07, 95% confidence interval, 0.73-1.41; P = 0.69). Conclusion: In patients with AF on OAC who underwent PCI for MI, treatment with ticagrelor or prasugrel vs. clopidogrel was associated with reduced ischaemic risk, without a concomitantly increased bleeding risk.

Aspirin-free antiplatelet strategies after percutaneous coronary interventions.

Dual antiplatelet therapy (DAPT) with aspirin and a platelet P2Y12 receptor inhibitor is the standard antithrombotic treatment after percutaneous coronary interventions (PCI). Several trials have challenged guideline-recommended DAPT after PCI by testing the relative clinical effect of an aspirin-free antiplatelet approach-consisting of P2Y12 inhibitor monotherapy after a short course (mostly 1-3 months) of DAPT-among patients undergoing PCI without a concomitant indication for oral anticoagulation (OAC). Overall, these studies have shown P2Y12 inhibitor monotherapy after short DAPT to be associated with a significant reduction in the risk of bleeding without an increase in thrombotic or ischaemic events compared with continued DAPT. Moreover, the effects of the P2Y12 inhibitor monotherapy without prior DAPT or following a very short course of DAPT after PCI are being investigated in emerging studies, of which one has recently reported unfavourable efficacy results associated with the aspirin-free approach compared with conventional DAPT. Finally, P2Y12 inhibitor alone has been compared with aspirin alone as chronic therapy after DAPT discontinuation, thus challenging the historical role of aspirin as a standard of care for secondary prevention following PCI. A thorough understanding of study designs, populations, treatments, results, and limitations of trials testing P2Y12 inhibitor monotherapy vs. DAPT or vs. aspirin is required to consider adopting this treatment in clinical practice. This review addresses the use of aspirin-free antiplatelet strategies among patients undergoing PCI without a concomitant indication for OAC, providing an overview of clinical evidence, guideline indications, practical implications, ongoing issues, and future perspectives.

Trajectories of P2Y12 inhibitor adherence in patients with acute coronary syndromes.

PURPOSE: P2Y12 inhibitors (P2Y12i) reduce cardiac events after acute coronary syndromes (ACS). However, suboptimal P2Y12i adherence persists. We aimed to examine P2Y12i non-adherence using group-based trajectory methods and to identify adherence predictors. METHODS: We conducted a population-based, retrospective cohort study using administrative data in Ontario, Canada of patients ≥65 years admitted for ACS between April 2014 and March 2018 with a P2Y12i dispensed within 7 days of discharge. We used group-based trajectory models to characterize longitudinal 1-year adherence patterns. Predictors associated with each adherence trajectory were identified by multinomial logistic regression. RESULTS: We included 11 917 patients using clopidogrel and 9763 using ticagrelor, aged [mean ± SD]: 77.33 ± 8.31/73.59 ± 6.79 years; men: 56.2%/65.4%, respectively. We identified 3 longitudinal adherence trajectories, that differed by agent: 75% of clopidogrel and 68% of ticagrelor patients showed a consistently adherent trajectory, while 13%/17% were gradually, and 12%/15% were rapidly non-adherent, respectively (p < 0.001). Differing baseline characteristics in each cohort were associated with observed adherence trajectories. Concomitant atrial fibrillation and prior bleeding history were associated with non-adherence among clopidogrel users. Among ticagrelor users, women and older persons were more likely to be rapidly non-adherent, adherence declining steeply starting 1 month post-ACS. CONCLUSIONS: We identified distinct adherence trajectories for clopidogrel and ticagrelor post-ACS, with 3 out of 4 clopidogrel patients but only 2 out of 3 ticagrelor patients in the consistently adherent trajectory. Intensive interventions targeted to the period of steep adherence decline post-ACS, particularly for women and older persons initiating ticagrelor, and patients with atrial fibrillation on clopidogrel should be considered and investigated further.

Preferred monotherapy after short-term dual antiplatelet therapy: Systematic review and network meta-analysis of randomized trials.

BACKGROUND: Randomized controlled trials (RCTs) have demonstrated the efficacy and safety of P2Y12 inhibitor monotherapy following short-term dual antiplatelet therapy (DAPT) in patients undergoing percutaneous coronary intervention (PCI). However, no studies have compared P2Y12 inhibitor and aspirin monotherapy following short-term DAPT. We aimed to compare available strategies for DAPT duration and post-DAPT antiplatelet monotherapy following PCI. METHODS: Seven DAPT strategies [ticagrelor or clopidogrel following 1-month DAPT, ticagrelor following 3-month DAPT, aspirin following 3-6 months of DAPT (reference strategy), aspirin or P2Y12 inhibitor following 6-18-months of DAPT, and DAPT for ≥18 months] were compared using a network meta-analysis. The primary efficacy outcome was defined as a composite of all-cause death, myocardial infarction, and stroke. The primary bleeding outcome was trial-defined major or minor bleeding. RESULTS: Our analysis identified 25 eligible RCTs, including 89,371 patients who underwent PCI. Overall, none of the strategies negatively affected the primary efficacy outcomes. For primary bleeding outcomes, ticagrelor following 3-month DAPT was associated with a reduced risk of primary bleeding outcomes (HR 0.73; 95 % CI 0.57-0.95). Clopidogrel following 1-month DAPT was also associated with a reduced risk of primary bleeding outcomes (HR 0.54; 95 % CI 0.34-0.85), however, the strategy was associated with an increased risk of myocardial infarction or stent thrombosis. Similar trends were observed among patients with acute coronary syndrome and high bleeding risk. CONCLUSIONS: Compared with aspirin monotherapy following short-term DAPT, ticagrelor following 3-month DAPT was associated with a reduced risk of primary bleeding outcomes without increasing any ischemic outcomes.

Personalized Approaches to Antiplatelet Treatment for Cardiovascular Diseases: An Umbrella Review.

Antiplatelet therapy is the cornerstone of antithrombotic prevention in patients with established atherosclerosis, since it has been proven to reduce coronary, cerebrovascular, and peripheral thrombotic events. However, the protective effect of antiplatelet agents is counterbalanced by an increase of bleeding events that impacts on patients' mortality and morbidity. Over the last years, great efforts have been made toward personalized antithrombotic strategies according to the individual bleeding and ischemic risk profile, aiming to maximizing the net clinical benefit. The development of risk scores, consensus definitions, and the new promising artificial intelligence tools, as well as the assessment of platelet responsiveness using platelet function and genetic testing, are now part of an integrated approach to tailored antithrombotic management. Moreover, novel strategies are available including dual antiplatelet therapy intensity and length modulation in patients undergoing myocardial revascularization, the use of P2Y12 inhibitor monotherapy for long-term secondary prevention, the implementation of parenteral antiplatelet agents in high-ischemic risk clinical settings, and combination of antiplatelet agents with low-dose factor Xa inhibitors (dual pathway inhibition) in patients suffering from polyvascular disease. This review summarizes the currently available evidence and provides an overview of the principal risk-stratification tools and antiplatelet strategies to inform treatment decisions in patients with cardiovascular disease.

Sex-Based Outcomes of P2Y12 Inhibitor Monotherapy After Three Months of Dual Antiplatelet Therapy in Patients Undergoing Percutaneous Coronary Intervention.

BACKGROUND: In patients undergoing percutaneous coronary intervention (PCI) in the SMART-CHOICE trial, P2Y12 inhibitor monotherapy after three months of dual antiplatelet therapy (DAPT) achieved clinical outcomes comparable to those of 12 months of DAPT. Nonetheless, the effects of sex on these outcomes remain unknown. METHODS: This open-label, non-inferiority, randomized study, conducted in 33 hospitals in South Korea, included 2,993 patients undergoing PCI with drug-eluting stents. Patients were randomly assigned to receive DAPT (aspirin plus a P2Y12 inhibitor) for three months then P2Y12 inhibitor alone for nine months, or DAPT for the entire 12 months. The primary endpoints were major adverse cardiac and cerebrovascular events (a composite of all-cause death, myocardial infarction, or stroke) 12 months after the index procedure. The bleeding endpoints were Bleeding Academic Research Consortium (BARC) bleeding types 2 to 5. RESULTS: Of the patients, 795 (26.6%) were women, who were older and had a higher prevalence of hypertension, diabetes, and dyslipidemia than men. The sexes exhibited comparable primary endpoints (adjusted hazard ratio [HR], 0.93; 95% confidence interval [CI], 0.55-1.55; P = 0.770) and bleeding endpoints (adjusted HR, 1.07; 95% CI, 0.63-1.81; P = 0.811). P2Y12 inhibitor monotherapy vs DAPT was associated with lower risk of BARC type 2 to 5 bleeding in women (adjusted HR, 0.40; 95% CI, 0.16-0.98; P = 0.045) but the difference was not statistically significant when using the Bonferroni correction. The primary endpoints were similar between treatment groups in both sexes. CONCLUSION: In both sexes undergoing PCI, P2Y12 inhibitor monotherapy after three months of DAPT achieved similar risks of the primary endpoints and the bleeding events compared with prolonged DAPT. Therefore, the benefits of early aspirin withdrawal with ongoing P2Y12 inhibitors may be comparable in women and men. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02079194.

Ticagrelor Enhances the Cardioprotective Effects of Ischemic Preconditioning in Stable Patients Undergoing Percutaneous Coronary Intervention: the TAPER-S Randomized Study.

BACKGROUND: Ticagrelor improves clinical outcomes in patients with acute coronary syndrome compared with clopidogrel. Ticagrelor also inhibits cell uptake of adenosine and has been associated with cardioprotective effects in animal models. We sought to investigate the potential cardioprotective effects of ticagrelor, as compared with clopidogrel, in stable patients undergoing percutaneous coronary intervention (PCI). METHODS AND RESULTS: This was a Prospective Randomized Open Blinded End-points (PROBE) trial enrolling stable patients with coronary artery disease (CAD) requiring fractional flow reserve (FFR)-guided PCI of intermediate epicardial coronary lesions. ST-segment elevation at intracoronary (IC)-ECG during a two-step sequential coronary balloon inflations in the reference vessel during PCI was used as an indirect marker of cardioprotection induced by ischemic preconditioning. The primary endpoint of the study was the comparison of the delta (Δ) (difference) ST-segment elevation measured by intracoronary-ECG during two-step sequential coronary balloon inflations. RESULTS: Fifty-three patients were randomized to either clopidogrel or ticagrelor. The study was stopped earlier because the primary endpoint was met at a pre-specified interim analysis. ΔST-segment elevation was significantly higher in ticagrelor as compared to clopidogrel arms (p<0.0001). Ticagrelor was associated with lower angina score during coronary balloon inflations. There was no difference in coronary microvascular resistance between groups. Adenosine serum concentrations were increased in patients treated with ticagrelor as compared to those treated with clopidogrel. CONCLUSIONS: Ticagrelor enhances the cardioprotective effects of ischemic preconditioning compared with clopidogrel in stable patients with CAD undergoing PCI. Further studies are warranted to fully elucidate the mechanisms through which ticagrelor may exert cardioprotective effects in humans. Clinical Trial Registration: http://www.clinicaltrials.gov. Unique Identifier: NCT02701140.