State of the art: duration of dual antiplatelet therapy after percutaneous coronary intervention and coronary stent implantation - past, present and future perspectives

Efficacy and Safety of Thirty-Day Dual-Antiplatelet Therapy Following Complex Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis

The optimal duration of DAPT after complex PCI remains under investigation. The purpose of this systematic review and meta-analysis was to explore the safety and efficacy of a one-month therapy period versus a longer duration of DAPT after complex PCI. We systematically screened three major databases, searching for randomized controlled trials or sub-analyses of them, which compared shortened DAPT (S-DAPT), namely, one month, and longer DAPT (L-DAPT), namely, more than three months. The primary endpoint was any Net Adverse Clinical Event (NACE), and the secondary was any MACE (Major Adverse Cardiac Event), its components (mortality, myocardial infarction, stroke, and stent thrombosis), and major bleeding events. Three studies were included in the analysis, with a total of 6275 patients. Shortening DAPT to 30 days after complex PCI did not increase the risk of NACEs (OR: 0.77, 95% CI: 0.52-1.14), MACEs, mortality, myocardial infractions, stroke, or stent thrombosis. Pooled major bleeding incidence was reduced, but this finding was not statistically significant. This systematic review and meta-analysis showed that one-month DAPT did not differ compared to a longer duration of DAPT after complex PCI in terms of safety and efficacy endpoints. Further studies are still required to confirm these findings.

Escalation and De-Escalation of Antiplatelet Therapy after Acute Coronary Syndrome or PCI: Available Evidence and Implications for Practice

Dual antiplatelet therapy (DAPT) is the gold standard for the antithrombotic management of patients with an acute coronary syndrome (ACS) or undergoing percutaneous coronary intervention (PCI). Implementation of intensified or prolonged DAPT regimens has proven to lower the risk of ischemic events but at the expense of increased bleeding. Importantly, bleeding is a predictor of poor prognosis. Risk stratification and selection of tailored antiplatelet strategies to maximize the net clinical benefit in individual patients with ACS or undergoing PCI is therefore potentially beneficial. Recently, novel approaches including DAPT de-escalation or escalation have been proposed as possible alternatives to standard DAPT. These strategies, which are generally based on patient's risk profile, genetics, and/or platelet function have been proposed to offer more tailored treatments in patients with ACS or PCI, with the ultimate goal of providing adequate ischemic protection while mitigating the risk of bleeding. This review summarizes the available evidence on DAPT de-escalation or escalation (both guided and unguided) and discusses the practical implications of these strategies in the contemporary management of patients with ACS and/or undergoing PCI.

Risk Scores of Bleeding Complications in Patients on Dual Antiplatelet Therapy: How to Optimize Identification of Patients at Risk of Bleeding after Percutaneous Coronary Intervention

Dual antiplatelet therapy (DAPT) with aspirin and a P2Y12 receptor inhibitor in patients undergoing percutaneous coronary intervention (PCI) reduces the risk of ischemic events but reduces the risk of ischemic events but increases the risk of bleeding, which in turn is associated with increased morbidity and mortality. With the aim to offer personalized treatment regimens to patients undergoing PCI, much effort has been devoted in the last decade to improve the identification of patients at increased risk of bleeding complications. Several clinical scores have been developed and validated in large populations of patients with coronary artery disease (CAD) and are currently recommended by guidelines to evaluate bleeding risk and individualize the type and duration of antithrombotic therapy after PCI. In clinical practice, these risk scores are conventionally computed at the time of PCI using baseline features and risk factors. Yet, bleeding risk is dynamic and can change over time after PCI, since patients can worsen or improve their clinical status and accumulate comorbidities. Indeed, evidence now exists that the estimated risk of bleeding after PCI can change over time. This concept is relevant, as the inappropriate estimation of bleeding risk, either at the time of revascularization or subsequent follow-up visits, might lead to erroneous therapeutic management. Serial evaluation and recalculation of bleeding risk scores during follow-up can be important in clinical practice to improve the identification of patients at higher risk of bleeding while on DAPT after PCI.

Opportunità cliniche e impatto sul sistema sanitario di un trattamento ottimale del paziente post-sindrome coronarica acuta

Despite the improvement of revascularization procedures, patients with acute coronary syndrome often develop recurrent ischemic events, suggesting a high residual cardiovascular risk in these patients, which requires a strict clinical monitoring as well as an optimal control of modifiable risk factors.

To this aim, an optimal management of index event and appropriate preventive measures are equally important. Hospital care by cardiologists should be followed by outpatient management by general practitioners, as established by specific diagnostic and therapeutic pathways, which should warrant an optimal support to the patient. A strict collaboration between hospital and primary care is crucial to monitor and adapt drug therapy after the acute event and improve adherence of the patients to prescribed treatments and implementation of life-style modifications, with benefits also in term of cost-effectiveness. In this context, individualized rehabilitation programs should also be offered to patients with acute coronary syndromes, in order to improve survival and quality of life.

Single, Dual, and Triple Antithrombotic Therapy in Cancer Patients with Coronary Artery Disease: Searching for Evidence and Personalized Approaches

Improvement in life expectancy of patients suffering from oncohematologic disorders has turned cancer from an acute into a chronic condition, making the management of comorbidities problematic, especially when it comes to both acute and chronic cardiovascular diseases. Treatment-related adverse events and drug-drug interactions often influence the therapeutic approach of patients with active malignancies and cardiovascular disease. Furthermore, tumor cells and platelets maintain a complex crosstalk that on one hand enhances tumor dissemination and on the other hand induces hemostasis abnormalities. Hence, clinicians should move carefully in the intricate land mines established by patients with active cancer under antithrombotic therapy. To date, there is no consensus on the antithrombotic treatment of patients with cardiovascular diseases and concomitant malignancies. The aim of this review is to collect the available scientific evidence, including the latest clinical trials and guidelines, in order to provide guidance on the management of antithrombotic treatment (both antiplatelet and anticoagulant therapy) in cancer patients with either pre-existent or new-onset coronary artery disease. Randomized-controlled trials on antithrombotic treatment in oncologic populations, which by far have thus far been excluded, have to be promoted to supply recommendations in the oncohematologic setting.

Impact of chronic kidney disease on platelet aggregation in patients with acute coronary syndrome

AIMS

Chronic kidney disease (CKD) is associated with increased thrombotic events and seems to influence platelet reactivity. Conflicting results have been published on platelet response in CKD patients with stable coronary artery disease. The aim of our study was to investigate the impact of CKD on platelet aggregation in acute coronary syndrome (ACS) patients receiving dual antiplatelet therapy, included the more potent P2Y12 inhibitors.

METHODS

We enrolled 206 patients with ACS, divided in two groups, according to the presence or the absence of moderate/severe CKD. Platelet aggregation was performed with light transmission aggregometry and results are expressed as percentage of maximum platelet aggregation. High residual platelet reactivity (HRPR) was defined as maximum platelet aggregation more than 59%.

RESULTS

Patients with CKD [estimate glomerular filtration rate (eGFR) < 60 ml/min/1.73 m, n = 28] were prevalent older, diabetic, had previous coronary revascularization. In these patients, platelet aggregation was significantly higher than in those with eGFR ≥ 60 ml/min/1.73 m (ADP 10 μmol/l: 28.46 ± 26.19 vs. 16.64 ± 12.79, P < 0.001; ADP 20 μmol/l: 30.07 ± 25.89 vs. 17.46 ± 12.82, P < 0.001). HRPR was observed in 4.4% of patients, with higher prevalence in those with eGFR less than 60 ml/min/1.73 m [21.4 vs. 1.7%, P < 0.001, odds ratio (OR) [95% confidence interval (CI)] = 15.91 (3.71-68.17), P < 0.001]. At multivariate analysis, after correction for baseline confounders, eGFR [adjusted OR (95% CI) = 0.95 (0.91-0.98), P = 0.007], together with the use of clopidogrel [adjusted OR (95% CI) = 23.59 (4.01-138.82), P < 0.001], emerged as determinants of HRPR.

CONCLUSION

In patients with ACS receiving dual antiplatelet therapy, CKD is associated with an increasing ADP-induced platelet aggregation and higher prevalence of HRPR, which is mainly correlated to clopidogrel use.

Short dual antiplatelet therapy followed by P2Y12 inhibitor monotherapy vs. prolonged dual antiplatelet therapy after percutaneous coronary intervention with second-generation drug-eluting stents: a systematic review and meta-analysis of randomized clinical trials

AIMS

After percutaneous coronary intervention (PCI) with second-generation drug-eluting stent (DES), whether short dual antiplatelet therapy (DAPT) followed by single antiplatelet therapy (SAPT) with a P2Y12 receptor inhibitor confers benefits compared with prolonged DAPT is unclear.

METHODS AND RESULTS

Multiple electronic databases, including PubMed, Scopus, Web of Sciences, Ovid, and ScienceDirect, were searched to identify randomized clinical trials comparing ≤3 months of DAPT followed by P2Y12 inhibitor SAPT vs. 12 months of DAPT after PCI with second-generation DES implantation. The primary and co-primary outcomes of interest were major bleeding and stent thrombosis 1 year after randomization. Summary hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by fixed-effect and random-effects models. Multiple sensitivity analyses including random-effects models 95% CI adjustment were applied. A sensitivity analysis comparing trials using P2Y12 inhibitor SAPT with those using aspirin SAPT was performed. A total of five randomized clinical trials (32 145 patients) were available. Major bleeding was significantly lower in the patients assigned to short DAPT followed by P2Y12 inhibitor SAPT compared with those assigned to 12-month DAPT (random-effects model: HR 0.63, 95% 0.45-0.86). No significant differences between groups were observed in terms of stent thrombosis (random-effects model: HR 1.19, 95% CI 0.86-1.65) and the secondary endpoints of all-cause death (random-effects model: HR 0.85, 95% CI 0.70-1.03), myocardial infarction (random-effects model: HR 1.05, 95% CI 0.89-1.23), and stroke (random-effects model: HR 1.08, 95% CI 0.68-1.74). Sensitivity analyses showed overall consistent results. By comparing trials testing ≤3 months of DAPT followed by P2Y12 inhibitor SAPT vs. 12 months of DAPT with trials testing ≤3 months of DAPT followed by aspirin SAPT vs. 12-month of DAPT, there was no treatment-by-subgroup interaction for each endpoint. By combining all these trials, regardless of the type of SAPT, short DAPT was associated with lower major bleeding (random-effects model: HR 0.63, 95% CI 0.48-0.83) and no differences in stent thrombosis, all-cause death, myocardial infarction, and stroke were observed between regimens.

CONCLUSION

After second-generation DES implantation, 1-3 months of DAPT followed by P2Y12 inhibitor SAPT is associated with lower major bleeding and similar stent thrombosis, all-cause death, myocardial infarction, and stroke compared with prolonged DAPT. Whether P2Y12 inhibitor SAPT is preferable to aspirin SAPT needs further investigation.

Prognostic and Practical Validation of ESC/EACTS High Ischemic Risk Definition on Long-Term Thrombotic and Bleeding Events in Contemporary PCI Patients

Aims: The ESC/EACTS myocardial revascularization guidelines recently standardized the definition of patients at high ischemic risk (HIR). However, the ability of ESC/EACTS–HIR criteria to stratify ischemic and bleeding risk in a contemporary real-world East Asian cohort remains unexplored.

Methods: A total of 10,167 consecutive patients undergoing PCI from prospective Fuwai PCI Registry (January 2013 to December 2013) were reviewed. ESC/EACTS–HIR features was defined as having at least one of the eight clinical and angiographic characteristics. The primary ischemic endpoint was target vessel failure (cardiac death, target vessel myocardial infarction [MI], or target vessel revascularization [TVR]); bleeding outcome was assessed using the BARC type 2, 3, or 5 bleeding. Median follow-up was 29 months.

Results: Compared with non-HIR patients, HIR patients ( n =5,149, 50.6%) were associated with increased risk for target vessel failure (adjusted hazard ratio [HR _adjust ]: 1.48 [1.25–1.74]) and patient-oriented composite outcome (HR _adjust : 1.44 [1.28–1.63]), as well as cardiac death, MI, and TVR. By contrast, the risk of clinically relevant bleeding was not significantly different between the two groups. (HR _adjust : 0.84 [0.66–1.06]). Greater than or equal to three implanted stents and diabetic patients with diffuse multivessel coronary disease emerged as independent predictors for long-term adverse outcomes. There was no significant interaction between high bleeding risk (HBR) status and clinical outcomes associated with ESC/EACTS–HIR criteria (all P _interaction ＞0.05).

Conclusion: The ESC/EACTS–HIR features identified patients at increased risk of thrombotic events, including cardiac death, but not for clinically relevant bleeding. Importantly, HBR did not modify cardiovascular risk subsequent to patients with ESC/EACTS–HIR features, suggesting its potential clinical applicability in tailoring antithrombotic therapy.

Dual antiplatelet therapy duration after percutaneous coronary intervention with drug-eluting stents: how short can we go?

Current guidelines recommend a duration of dual antiplatelet therapy (DAPT) with aspirin and oral P2Y<inf>12</inf> receptor inhibitors following percutaneous coronary intervention (PCI) with second-generation drug-eluting stents (DES) of 6 months for most patients with stable coronary disease and of 12 months for most patients with acute coronary syndromes. Large evidence from randomised clinical trials of shorter DAPT regimens after PCI with newer-generation DES is now emerging in heterogenous patient population not selected on the basis of high bleeding risk as well as in patients at high bleeding risk. The scope of this review is to provide an update on the benefits and harms of these short DAPT regimens and to discuss future directions in DAPT strategies after PCI with newer generation DES.

Novel Perspective for Antithrombotic Therapy in TAVI

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While surgical aortic valve replacement (SAVR) was for years the only available treatment for symptomatic aortic stenosis, the introduction of transcatheter aortic valve implantation (TAVI) in 2002 and the improvement of its technical aspects in the following years, has holistically changed the synchronous therapeutic approach of aortic valve stenosis. Recent evidence has expanded the indication of TAVI from high to lower surgical risk populations with symptomatic aortic stenosis. The administration of antithrombotic therapy periprocedurally and its maintenance after a successful TAVI is crucial for the prevention of complications and affects postprocedural survival. Randomized controlled trials investigating the appropriate combination and the duration of antithrombotic treatment after TAVI are for the moment scarce. This review article sheds light on the underlying pathogenetic mechanisms contributing in periprocedural TAVI thrombotic complications and discuss the efficacy of current antithrombotic policies as evaluated in randomized trials.

Determinants and Clinical Outcomes of Extended Dual Antiplatelet Therapy over 3 Years after Drug-Eluting Stent Implantation: A Retrospective Analysis

PURPOSE

Although current guidelines recommend the administration of dual antiplatelet therapy (DAPT) for up to 12 months after the implantation of a drug-eluting stent (DES), extended DAPT is frequently used in real-world practice.

MATERIALS AND METHODS

From the Korean Multicenter Angioplasty Team registry, we identified a total of 1414 patients who used DAPT for >3 years after DES implantation (extended-DAPT group) and conducted a landmark analysis at 36 months after the index procedure. We evaluated the determinants for and long-term outcomes of extended DAPT and compared the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE), defined as the composite of all-cause death, myocardial infarction, stent thrombosis, and stroke, between the extended-DAPT group and the guideline-DAPT group [DAPT <1 year after DES implantation (n=1273)].

RESULTS

Multivariate analysis indicated the occurrence of acute coronary syndrome as the most significant clinical determinant of the use of extended DAPT. Bifurcation, stent diameter ≤3.0 mm, total stented length ≥28 mm, and use of first-generation DESs were also significant angiographic and procedural determinants. MACCE rates were similar between the extended-DAPT group and the guideline-DAPT group in crude analysis [hazard ratio (HR), 1.08; 95% confidence interval (CI), 0.69-1.68; p=0.739] and after propensity matching (HR, 1.22; 95% CI, 0.72-2.07; p=0.453). Major bleeding rates were comparable between the two groups.

CONCLUSION

In patients undergoing percutaneous coronary intervention, indefinite use of DAPT does not show superior outcomes to those of guideline-DAPT. Major bleeding rates are also similar.

One-year efficacy and safety of prasugrel and ticagrelor in patients with acute coronary syndromes: Results from a prospective and multicentre ACHILLES registry

BACKGROUND

Prasugrel and ticagrelor have demonstrated higher efficacy than clopidogrel in their main clinical trials for patients with acute coronary syndrome (ACS). However, the long-term prognosis and different clinical characteristics related to the type of antiplatelet prescription in current clinical practice ACS patients have not been analysed in depth. The objective of this study was to analyse the clinical profile of ACS and the efficacy and safety of novel oral P2Y₁₂ inhibitors in current clinical practice patients discharged afterACS.

METHODS

We collected data from the ACHILLES registry, and an observational, prospective and multicentre registry of patients discharged after ACS. We analysed baseline characteristics, clinical profile and therapy during ACS admission and compared with the different treatments at discharge. After 1 year of follow-up, ischaemic and major bleeding events were analysed. Multivariate Cox regression analysis and Kaplan Meier curves were also plotted.

RESULTS

Of 1717 consecutive patients, 1294 (75.4%) were discharged with a P2Y12 inhibitor without oral anticoagulation. Novel oral P2Y₁₂ inhibitors were indicated in 47%. Patients treated with clopidogrel were elderly (69.1 ± 13.4 vs 60.4 ± 11.5 years; P < .001) and had a higher prevalence of cardiovascular risk factors. GRACE and CRUSADE scores were higher in the clopidogrel than in novel oral P2Y₁₂ inhibitors group (P < .001). After 1 year of follow-up, 64(5.0%/year) patients had a new myocardial infarction, 127(10.0%/year) had a major adverse cardiovascular event (MACE) and 78(6.1%/year) died. Patients treated with clopidogrel had a significantly higher annual rate of cardiovascular mortality, MACE and all-cause mortality (allP < .001) without differences in major bleeding (P = .587) compared with novel oral P2Y₁₂ inhibitors. After multivariate adjustment for the main clinical variables related to adverse prognosis in ACS patients, the discharge with novel oral P2Y₁₂ inhibitors therapy was independently associated with lower risk of all-cause mortality (HR0.49, 95% CI [0.24-0.98], P = .044) and lower risk of MACE (HR0.64, 95% CI [0.41-0.98], P = .044).

CONCLUSIONS

In this prospective, observational and current clinical practice ACS registry, the use of novel oral P2Y₁₂ inhibitors was associated with a reduction in adverse events compared with clopidogrel in patients with ACS. Novel oral P2Y₁₂ inhibitors prescription at discharge was independently associated with lower all-cause mortality and MACE without differences in bleeding events. However, clopidogrel remained the most common P2Y12 inhibitor employed for ACS, especially in older and high-risk patients.

Use of PRECISE-DAPT Score and Admission Platelet Count to Predict Mortality Risk in Patients With Acute Coronary Syndrome

The PREdicting bleeding Complications In patients undergoing Stent implantation and subsEquent Dual Antiplatelet Therapy (PRECISE-DAPT) score has been validated to predict bleeding complications in patients undergoing stent implantation and dual antiplatelet therapy. This score does not include the platelet count (PC), which has been shown to be an independent marker of mortality in patients with acute coronary syndrome (ACS). We assessed the role of the PRECISE-DAPT score calculated on admission for mortality risk prediction and evaluated whether the predictive accuracy of this score improved by adding the PC. In a retrospective cohort study of 1000 patients with ACS, after adjustment for relevant covariates, a PRECISE-DAPT score ≥25 was independently associated with mortality (hazard ratio [HR]: 7.91; 95% confidence interval [CI]: 4.37-14.30). When this score was combined with PC, compared to patients with PRECISE-DAPT <25 and PC ≥150 × 10⁹/L, the adjusted HR was 7.2 (95% CI 2.4-21.6) for those with PRECISE-DAPT <25 and PC <150 × 10⁹/L; 10.7 (95% CI: 5.2-21.9) for those with PRECISE-DAPT ≥25 and PC ≥150 × 10⁹/L; and 17.9 (95% CI 7.0-45.4) for those with PRECISE-DAPT ≥25 and PC <150 × 10⁹/L. Selecting thresholds for high-risk designation, the PRECISE-DAPT score integrated with PC had a higher prediction value, compared to the PRECISE-DAPT and Global Registry of Acute Coronary Events scores.

Duration of Dual Antiplatelet Therapy in Patients with CKD and Drug-Eluting Stents: A Meta-Analysis

BACKGROUND AND OBJECTIVES

Whether prolonged dual antiplatelet therapy (DAPT) is more protective in patients with CKD and drug-eluting stents compared with shorter DAPT is uncertain. The purpose of this meta-analysis was to examine whether shorter DAPT in patients with drug-eluting stents and CKD is associated with lower mortality or major adverse cardiovascular event rates compared with longer DAPT.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A Medline literature research was conducted to identify randomized trials in patients with drug-eluting stents comparing different DAPT duration strategies. Inclusion of patients with CKD was also required. The primary outcome was a composite of all-cause mortality, myocardial infarction, stroke, or stent thrombosis (definite or probable). Major bleeding was the secondary outcome. The risk ratio (RR) was estimated using a random-effects model.

RESULTS

Five randomized trials were included (1902 patients with CKD). Short DAPT (≤6 months) was associated with a similar incidence of the primary outcome, compared with 12-month DAPT among patients with CKD (48 versus 50 events; RR, 0.93; 95% confidence interval [95% CI], 0.64 to 1.36; P=0.72). Twelve-month DAPT was also associated with a similar incidence of the primary outcome compared with extended DAPT (≥30 months) in the CKD subgroup (35 versus 35 events; RR, 1.04; 95% CI, 0.67 to 1.62; P=0.87). Numerically lower major bleeding event rates were detected with shorter versus 12-month DAPT (9 versus 13 events; RR, 0.69; 95% CI, 0.30 to 1.60; P=0.39) and 12-month versus extended DAPT (9 versus 12 events; RR, 0.83; 95% CI, 0.35 to 1.93; P=0.66) in patients with CKD.

CONCLUSIONS

Short DAPT does not appear to be inferior to longer DAPT in patients with CKD and drug-eluting stents. Because of imprecision in estimates (few events and wide confidence intervals), no definite conclusions can be drawn with respect to stent thrombosis.

Design and rationale of the Management of High Bleeding Risk Patients Post Bioresorbable Polymer Coated Stent Implantation With an Abbreviated Versus Standard DAPT Regimen (MASTER DAPT) Study

BACKGROUND

The optimal duration of antiplatelet therapy in high-bleeding risk (HBR) patients with coronary artery disease treated with newer-generation drug-eluting bioresorbable polymer-coated stents remains unclear.

DESIGN

MASTER DAPT (clinicaltrial.govNCT03023020) is an investigator-initiated, open-label, multicenter, randomized controlled trial comparing an abbreviated versus a standard duration of antiplatelet therapy after bioresorbable polymer-coated Ultimaster (TANSEI) sirolimus-eluting stent implantation in approximately 4,300 HBR patients recruited from ≥100 interventional cardiology centers globally. After a mandatory 30-day dual-antiplatelet therapy (DAPT) run-in phase, patients are randomized to (a) a single antiplatelet regimen until study completion or up to 5 months in patients with clinically indicated oral anticoagulation (experimental 1-month DAPT group) or (b) continue DAPT for at least 5 months in patients without or 2 in patients with concomitant indication to oral anticoagulation, followed by a single antiplatelet regimen (standard antiplatelet regimen). With a final sample size of 4,300 patients, this study is powered to assess the noninferiority of the abbreviated antiplatelet regimen with respect to the net adverse clinical and major adverse cardiac and cerebral events composite end points and if satisfied for the superiority of abbreviated as compared to standard antiplatelet therapy duration in terms of major or clinically relevant nonmajor bleeding. Study end points will be adjudicated by a blinded Clinical Events Committee.

CONCLUSIONS

The MASTER DAPT study is the first randomized controlled trial aiming at ascertaining the optimal duration of antiplatelet therapy in HBR patients treated with sirolimus-eluting bioresorbable polymer-coated stent implantation.

Thromboembolic and Bleeding Complications in Transcatheter Aortic Valve Implantation: Insights on Mechanisms, Prophylaxis and Therapy

Transcatheter aortic valve implantation (TAVI) has emerged as an important alternative to surgical aortic valve repair (SAVR) for patients with severe aortic stenosis. This rapidly advancing field has produced new-generation devices being delivered with small delivery sheaths, embolic protection devices and improved retrieval features. Despite efforts to reduce the rate of thrombotic complications associated with TAVI, valve thrombosis and cerebral ischaemic events post-TAVI continue to be a significant issue. However, the antithrombotic treatments utilised to prevent these dreaded complications are based on weak evidence and are associated with high rates of bleeding, which in itself is associated with adverse clinical outcomes. Recently, experimental data has shed light on the unique mechanisms, particularly the complex haemodynamic changes at sites of TAVI, that underpin the development of post-TAVI thrombosis. These new insights regarding the drivers of TAVI-associated thrombosis, coupled with the ongoing development of novel antithrombotics which do not cause bleeding, hold the potential to deliver newer, safer therapeutic paradigms to prevent post-TAVI thrombotic and bleeding complications. This review highlights the major challenge of post-TAVI thrombosis and bleeding, and the significant issues surrounding current antithrombotic approaches. Moreover, a detailed discussion regarding the mechanisms of post-TAVI thrombosis is provided, in addition to an appraisal of current antithrombotic guidelines, past and ongoing clinical trials, and how novel therapeutics offer the hope of optimizing antithrombotic strategies and ultimately improving patient outcomes.

Impact of angiographic coronary artery disease complexity on ischemic and bleeding risks and on the comparative effectiveness of zotarolimus-eluting vs. bare-metal stents in uncertain drug-eluting stent candidates

BACKGROUND

The impact of coronary artery disease (CAD) extension/complexity on outcomes and on the comparative benefits/risks of zotarolimus-eluting stent (ZES) versus bare-metal stents (BMS) remains unclear in patients at high risk of bleeding or thrombosis or at low restenosis risk.

METHODS

We performed a post-hoc analysis of the ZEUS trial. The impact of coronary anatomic complexity measured by the SYNTAX score on the differences in outcomes following ZES and BMS was assessed at 1 year.

RESULTS

The mean SYNTAX score was 16.3 ± 13.1 with a median of 12 (IQR: 7 to 22). We stratified patients according to SYNTAX tertiles (0-8: n = 563; >8-19 n = 532; >19: n = 511), and observed that the higher the score, the correspondingly higher was the rate of the primary endpoint of major adverse cardiovascular events (MACE) and other ischemic events, but not bleeding after adjustment. The superior efficacy of ZES versus BMS for MACE was consistent across SYNTAX tertiles (tertile 1: HR 0.71, 95% CI 0.44-1.13; tertile 2: HR 0.71, 95% CI 0.46-1.09; tertile 3: HR 0.83, 95% CI 0.61-1.10) without significant heterogeneity (p for trend = 0.55). This between-groups difference mainly reflected a reduction in MI and TVR without effect on mortality. There was no significant interaction between the SYNTAX score and allocated stent type with respect to ischemic and bleeding endpoints.

CONCLUSIONS

The SYNTAX score was predictor of major adverse cardiovascular events but not bleeding and ZES provided superior efficacy and safety than BMS across the whole spectrum of CAD complexity. SYNTAX score may be routinely used for the assessment of the ischemic risk (but not bleeding) after PCI and should not guide the decision-making for DES versus BMS in patients undergoing PCI.

Effects of Carvedilol Versus Metoprolol on Platelet Aggregation in Patients With Acute Coronary Syndrome: The PLATE-BLOCK Study

Platelet aggregation plays a pivotal role in acute coronary syndrome (ACS). In this setting, β-blockers (BBs) are used to counteract the effects of catecholamines on heart. Circulating catecholamines can also potentiate platelet reactivity, mainly through α₂- and β₂-adrenoceptors on human platelets' surface, thus BB may affect platelet aggregation; however, the effects of different BBs on platelet aggregation in contemporary-treated patients with ACS have been poorly investigated. One hundred patients with ACS on dual antiplatelet therapy with aspirin and ticagrelor were randomized to receive treatment with carvedilol, a nonselective BB (n = 50), or metoprolol, a selective β₁-blocker (n = 50), at maximum tolerated dose. Light transmission aggregometry was performed at randomization (T0) and at 30-day follow-up (T30), and the results were expressed as a percentage of maximum platelet aggregation (MPA). The primary end point was epinephrine-induced MPA at 30 days. Patients were predominantly men (80%), and mean age was 57.3 ± 9.7 years. The 2 randomized groups were well balanced for baseline characteristics. At T0, mean MPA was similar between the groups (18.96 ± 9.05 vs 18.32 ± 9.21 with 10 µM epinephrine, 14.42 ± 9.43 vs 15.98 ± 10.08 with 20 µM adenosine diphophate (ADP), and 13.26 ± 9.83 vs 14.30 ± 9.40 with 10 µM ADP for carvedilol and metoprolol, respectively, all p = NS). At 30 days, platelet aggregation induced by epinephrine was significantly lower in the carvedilol group than in the metoprolol group (23.52 ± 10.25 vs 28.72 ± 14.37, p = 0.04), with a trend toward the lower values of ADP-induced MPA (20 µM ADP 19.42 ± 13.84 vs 24.16 ± 13.62, p = 0.09; 10 µM ADP 19.12 ± 12.40 vs 22.57 ± 13.59, p = 0.19). In conclusion, carvedilol, a nonselective BB, reduces residual platelet reactivity in patients with ACS compared with the selective BB, metoprolol.