Biogas recovery from a state-of-the-art Italian landfill.

The Fossetto landfill has operated in the municipality of Monsummano Terme (Tuscany, Italy) since 1988, being considered a state-of-the-art landfill for 35 years. Initially, Fossetto acted as a conventional sanitary landfill for mixed municipal solid waste. With changes in regulations and technology, the Fossetto landfill was gradually equipped with a biogas recovery and valorisation system, a mechanical-biological treatment (MBT) plant in 2003 and a reverse osmosis leachate treatment plant, so the concentrated leachate has been recirculated back into the landfill body since 2006. Long-term biogas monitoring, enables the calculation of the efficiency of biogas recovery using a rather simplified methodology, which was assessed as being approximately 40% over the prior ten-years period. This value was lower than expected, confirming the results of previous studies and indicating the need of attributes. Applying the USEPA LandGEM model showed that the adoption of MBT substantially reduced biogas generation yields and rates by up to approximately 90% which was facilitated by the adoption of landfill leachate recirculation transforming the conventional landfill into a bioreactor. Detailed fugitive emission monitoring has allowed the evaluation of the impact of the cover type (final or temporary) and the emissions hotspots. From these results, possible remedial actions have been suggested including the more frequent monitoring of the fugitive emissions using simple and cost-effective methods (e.g., UAVs). Approximately 50% of fugitive emissions can be attributed to emissions hotspots, which reduce biogas recovery and the efficiency of temporary covers.

Impact of Tafamidis on Delaying Clinical, Functional, and Structural Cardiac Changes in Patients with Wild-Type Transthyretin Amyloid Cardiomyopathy.

Background: This study aimed to evaluate the effect of treatment with tafamidis on clinical, laboratory, functional, and structural cardiovascular imaging parameters at the 12-month follow-up timepoint in patients with wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) and to assess the response to treatment in terms of disease progression. Methods: Patients with ATTRwt-CM undergoing treatment with tafamidis for >12 months were included. The patients underwent a comprehensive evaluation (including echocardiography, cardiac magnetic resonance imaging, six-minute walking test, assessment of quality of life, and laboratory tests) at baseline and the 12-month follow-up timepoint. Disease progression was assessed using a set of tools proposed by an international panel of experts, evaluating three main domains (clinical, biochemical, and structural). Results: The study cohort consisted of 25 patients (mean age of 75.9 ± 6.1 years, with 92% males). At the 12-month follow-up timepoint, an improvement in quality of life calculated with the KCCQ overall score (64 ± 20 vs. 75 ± 20, p = 0.002) and a reduction in pulmonary artery pressure (34 ± 10 mmHg vs. 30 ± 5 mmHg, p-value = 0.008) and in native T1 time were observed (1162 ± 66 ms vs. 1116 ± 52 ms, p-value = 0.001). Clinical, biochemical, and structural disease progression was observed in 6 (24%), 13 (52%), and 7 (28%) patients, respectively. Overall disease progression was observed in two patients (8%). Conclusions: This study described the impact of tafamidis treatment on clinical, laboratory, and functional parameters. Disease progression, assessed using a multiparametric tool recommended by a recent position paper of experts, was observed in a minority of patients.

Patterns of Left Ventricular Remodelling in Children and Young Patients with Hypertrophic Cardiomyopathy.

Introduction: The aim of this study was to evaluate the age at onset, clinical course, and patterns of left ventricular (LV) remodelling during follow-up in children and young patients with hypertrophic cardiomyopathy (HCM). Methods: We included consecutive patients with sarcomeric or non-syndromic HCM below 18 years old. Three pre-specified patterns of LV remodelling were assessed: maximal LV wall thickness (MLVWT) thickening; MLVWT thinning with preserved LV ejection fraction; and MLVWT thinning with progressive reduction in LV ejection fraction (hypokinetic end-stage evolution). Results: Fifty-three patients with sarcomeric/non-syndromic HCM (mean age 9.4 ± 5.5 years, 68% male) fulfilled the inclusion criteria. In total, 32 patients (60%) showed LV remodelling: 3 patients (6%) exhibited MLVWT thinning; 16 patients (30%) showed MLVWT thickening; and 13 patients (24%) progressed to hypokinetic end-stage HCM. Twenty-one patients (40%) had no LV remodelling during follow-up. In multivariate analysis, MLVWT was a predictor of the hypokinetic end-stage remodelling pattern during follow-up (OR 1.17 [95%CI 1.01-1.36] per 1 mm increase, p-value 0.043), regardless of sarcomeric variants and New York Heart Association class. Two patients with sarcomeric HCM, showing a pattern of MLVWT regression during childhood, experienced progression during adolescence. Conclusions: Different patterns of LV remodelling were observed in a cohort of children with sarcomeric/non-syndromic HCM. Interestingly, a pattern of progressive MLVWT thinning during childhood, with new progression of MLVWT during adolescence, was noted. A better understanding of the remodelling mechanisms in children with sarcomeric HCM may be relevant to defining the timing and possible efficacy of new targeted therapies in the preclinical stage of the disease.

Management of patients treated with oral anticoagulant therapy undergoing percutaneous coronary intervention with stent implantation: the PERSEO Registry.

In patients on oral anticoagulant (OAC) therapy undergoing percutaneous coronary intervention with stent (PCI), international guidelines endorse the use of direct oral anticoagulants (DOAC) rather than vitamin K antagonists (VKA) and dual antithrombotic therapy (DAT) rather than triple antithrombotic therapy (TAT). Aim of this study was to evaluate contemporary real-world data on antithrombotic regimens and outcome in patients on OAC undergoing PCI with stent. Consecutive patients on OAC undergoing PCI were enrolled in the multicentre, prospective, observational PERSEO registry (NCT03392948). Primary end-point was net adverse clinical events (NACE) with VKA vs DOAC, whereas a secondary pre-specified end-point was NACE with DAT vs TAT both at 1-year follow-up. From February 2018 to February 2022, 1234 consecutive patients were included. The main indication for OAC was atrial fibrillation (86%) and the mean CHA2DS2VASc and HAS-BLED scores were 4±2 and 3.6±1, respectively. Of the 1228 patients discharged alive, 222 (18%) were on VKA and 1006 (82%) on DOAC (p<0.01). DAT was employed in 197 patients whereas TAT in 1028. At follow-up, NACE rate was significantly higher with VKA compared to DOAC (23% vs 16%, p=0.013) and confirmed after propensity score adjustment. TAT and DAT did not differ as regards NACE rate (17% vs 19%, p=0.864) even though, compared to TAT, DAT was associated with less major bleedings (2% vs 5%, p= 0.014), confirmed after propensity score adjustment. In conclusion, in patients on OAC undergoing PCI, DOAC, compared to VKA, was associated with a significantly lower occurrence of NACE and DAT reduced bleedings compared to TAT.

Insulin Resistance/Hyperinsulinemia as an Independent Risk Factor That Has Been Overlooked for Too Long.

Unfortunately, cardiovascular diseases and cancers are still the leading causes of death in developed and developing countries despite the considerable progress made in the prevention and treatment of diseases. Maybe we missed something? Insulin resistance (IR) with associated hyperinsulinemia (Hypein) is a silent pandemic whose prevalence is continually growing in developed and developing countries, now exceeding 51% of the general population. IR/Hypein, despite the vast scientific literature supporting its adverse action on the development of type 2 diabetes, cardiovascular alterations, tumors, neurological disorders, and cellular senescence, is not yet considered an independent risk factor and, therefore, is not screened in the general population and adequately treated. There are now numerous substances, drugs, and natural substances that, in association with the correction of a wrong lifestyle, can help to reduce IR/Hypein. We are convinced that the time has come to implement a prevention plan against this critical risk factor. Therefore, this manuscript aims to highlight IR/Hypein as an independent risk factor for type 2 diabetes, cardiovascular diseases, cancers, cellular senescence, and neuropsychiatric disorders, supporting our conviction with the available scientific literature on the topic.

[SIC Position paper: Treat to prevent the first event - intensive LDL cholesterol lowering in patients at very high cardiovascular risk without a previous cardiovascular event. From ESC guidelines to clinical practice]. / Position paper SIC: Trattare per prevenire ­ la riduzione intensiva del colesterolo LDL nel paziente a rischio cardiovascolare molto alto senza pregresso evento. Dalle linee guida ESC alla pratica clinica.

Cardiovascular (CV) diseases account for over 4 million deaths every year in Europe and over 220 000 deaths in Italy, representing the leading cause of morbidity and mortality worldwide. The European Society of Cardiology (ESC) guidelines have visionary included in the at very high CV risk group patients without previous acute ischemic events, such as those with subclinical atherosclerosis, chronic coronary syndrome or peripheral arterial disease, familial hypercholesterolemia, diabetes mellitus with target organ damage or multiple associated risk factors, and those with high calculated CV risk score, recommending to consider them and to achieve the same LDL-cholesterol targets as for secondary prevention patients. The aim of this position paper is to provide an updated overview of ESC guidelines that focuses on these patient categories to raise awareness within the clinical community regarding CV risk reduction in this specific epidemiological context.

Low platelet count at admission has an adverse impact on outcome in patients with acute coronary syndromes: from the START Antiplatelet registry.

Some previous observations suggest that a low platelet count is associated with an increased risk of adverse outcomes in patients with acute coronary syndromes (ACS). However, most of the data come from post-hoc analyses of randomized controlled trials and from studies including thrombocytopenia developed during hospital stay. Our aim was to assess the impact of low platelet count at admission on cardiovascular outcomes and treatment approach in patients hospitalized for ACS in a current real-life setting in Italy. Patients admitted to Italian coronary care units for ACS were enrolled in the START-ANTIPLATELET registry. Baseline clinical characteristics and treatment at discharge were recorded. Patients were followed-up at 6 months, 1 year and yearly thereafter. Low platelet count was defined as a count at admission < 150 > 100 k/µl or < 100 k/µL. Among 1894 enrolled patients, 157 (8.3%) had a platelet count < 150 > 100 k/µl and 30 (1.6%) < 100 k/µl. The median follow-up was 12.3 months (0.4-50.1). patients with low platelets were older (72 ± 10.4 vs 66 ± 12.4 years, p = 0.006), more frequently males (82.9 vs 72.1%, p = 0.001), hypertensive (90.0% vs 70.4%, p = 0.03), with non-valvular atrial fibrillation (NVAF) (17.1 vs 8.6%, p = 0.02), and peripheral arterial disease (11.5 vs 6.2% p = 0.01) and/or had a previous myocardial infarction (40 vs 18.7%, p = 0.008) and/or a PCI (14.6 vs 7.8%, p = 0.001) than patients with normal platelets. A slightly, but significantly, lower percentage of thrombocytopenic patients were treated with primary PCI (78.1 vs 84.4%, p = 0.04) and they were more frequently discharged on aspirin plus clopidogrel rather than aspirin plus newer P2Y12 antagonists (51.9 vs 65.4%, p = 0.01). MACE-free survival was significantly shorter in thrombocytopenic patients compared to patients with normal platelets (< 150 > 100 k/µl: 37.6 vs 41.8 months, p = 0.002; HR = 2.7, 95% CIs 1.4-5.2; < 100 k/µl: 31.7 vs 41.8 months, p = 0.01; HR = 6.5, 95% CIs 1.5-29.1). At multivariate analysis, low platelet count, age at enrollment, low glomerular filtration rate, low ejection fraction, a previous ischemic stroke and NVAF were independent predictors of MACE. A low platelet count at admission identifies a subgroup of ACS patients with a significantly increased risk of MACE and these patients should be managed with special care to prevent excess adverse outcomes.

Strike early-strike strong lipid-lowering strategy with PCSK9i in ACS patients. Real-world evidence from AT-TARGET-IT registry.

AIMS: No data are available on early initiation of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) in patients with acute coronary syndrome (ACS) in real-world. This study investigates the effects of PCSK9i started at time of ACS hospitalization on lipid control and major CV events in real-world. METHODS: The lipid control outcome was the percentage of patients reaching the LDL-C target of < 55 mg/dL at first lipid control. The clinical outcome was the incidence of composite major CV events (all cause death, non-fatal MI, non-fatal stroke, and ischemia-driven revascularization) during follow-up in relation to quartiles of LDL-C at first lipid control. RESULTS: We included 771 patients with ACS from AT-TARGET-IT registry, receiving PCSK9i prescription during hospitalization or at discharge. Median LDL-C was 137 mg/dL and decreased to 43 mg/dL at first lipid control. 527 (68.3%) patients achieved LDL-C target at the first lipid control at a median time of 37 days from hospitalization; of them, 404 (76.8%) were discharged on statin plus ezetimibe background therapy. Event curves through a median follow-up of 11 months across quartiles of LDL-C showed a stepwise lower risk of 4P-MACE, 3P-MACE, all-cause mortality, and ischemia-driven revascularization in lower quartile of LDL-C values at first lipid control (<23 mg/dL) and in patients reaching LDL-C <55 mg/dL. CONCLUSIONS: Intensive and early lipid-lowering therapy using PCSK9i in patients with ACS (strike early strike strong strategy) is safe and effective in clinical practice and associated with a reduction of residual CV risk.

This study, from AT-TARGET-IT registry, investigates the effects of PCSK9i started at time of ACS hospitalization on lipid control and major CV events in real-world. Intensive and early PCSK9i therapy reduce composite major cardiovascular (CV) events in patients in reaching LDL-C target values. A strike early-strike strong strategy is safe and effective.

Wastewater treatment in lagoons: A systematic review and a meta-analysis.

This study has carried out a systematic review of 36 scientific papers (reporting 63 case studies) published in the last 15 years about the treatment of industrial, agri-food and municipal wastewater in lagoons. A concentration of studies from a few countries (Italy, Algeria and Iran) and about municipal wastewater (70% of papers) was revealed by the bibliographic analysis. Aeration was supplied in more than 50% of case studies; the storage capacity of lagoons (adopted as a measure of size) was extremely variable (over seven orders of magnitude), while their depth was generally lower than a few metres. The efficiency of lagoon treatments at removing COD was in a wide range (25-98%). Very few studies analysed the energy intensity of treatments in lagoons. The meta-analysis applied to a further selection of 10 papers with 29 case studies revealed significant differences in pH and dissolved oxygen concentration, due to aeration or type of treated wastewater. Treatment efficiency was higher in aerated lagoons compared to non-aerated systems, and did not depend on the type of treated wastewater. Based on the analysis of the reviewed papers, an urgent research need on this topic arises, mainly due to the oldness of most analysed studies. Practical suggestions are given to optimise the depuration performances of lagoons: (i) application of intermittent and night aeration; (ii) reduced air flow rates; (iii) adaptation of microbial biomass to high contents of inhibiting compounds in wastewater; (iv) construction of baffles to keep the planned hydraulic retention time avoiding short-circuit; (v) integration of lagoons with other treatments (e.g., constructed wetlands); (vi) ferti-irrigation of crops with lagoon effluents rather than disposal into water bodies.

A short bibliographic review concerning biomethane production from wastewater sludge.

Biomethane production by anaerobic digestion (AD) of sludge from municipal wastewater treatment is a viable practice to valorise the residues of these plants. However, although the relevant literature is abundant, no comprehensive reviews have been recently published on this topic. Detailed information concerning the factors influencing the AD process and values of biomethane production from the sludge from municipal wastewater treatment plants (MWWTPs) on the global scale may support technicians and researchers in both the planning and the design steps of an AD process. This study proposes a systematic review and a meta-analysis of the factors that noticeably influence biomethane yield deriving from AD of sludge from MWWTP. The reported values were systematically analysed compared to the main factors driving AD, including publication year, geographical area of each study, type of digested sludge, treatment in the water line of the MWWTP, possible sludge pre-treatments, type of digestion process, hydraulic retention time (HRT) and temperature regime of the AD process. A higher biomethane production was registered in North American plants compared to countries in other continents. Older studies published between 2001 and 2005 reported lower mean values compared to the more recent experiments. A gradient of 'primary sludge' > 'mixed sludge' > 'wastewater activated sludge' was found for the mean biomethane yield in relation to the digested sludge type. The mean biomethane yields for different types of sludge on a global scale are 0.425, 0.296 and 0.176 Nm3 kg VS-1 for primary sludge, mixed sludge and waste activated sludge, respectively. Overall, the study demonstrates: (i) the very large variability of biomethane yields from AD of the residues from MWWTPs (mainly due to the different characteristics of sludge) and (ii) the non-significance of some factors (i.e. treatment in the water line, pre-treatments, type of process, HRT and temperature regime) on energy yields from the AD process.

Intravenous antiplatelet therapy in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention : A report from the INVEST-STEMI group.

The use of intravenous antiplatelet therapy during primary percutaneous coronary intervention (PPCI) is not fully standardized. The aim is to evaluate the effectiveness and safety of periprocedural intravenous administration of cangrelor or tirofiban in a contemporary ST-segment elevation myocardial infarction (STEMI) population undergoing PPCI. This was a multicenter prospective cohort study including consecutive STEMI patients who received cangrelor or tirofiban during PPCI at seven Italian centers. The primary effectiveness measure was the angiographic evidence of thrombolysis in myocardial infarction (TIMI) flow < 3 after PPCI. The primary safety outcome was the in-hospital occurrence of BARC (Bleeding Academic Research Consortium) 2-5 bleedings. The study included 627 patients (median age 63 years, 79% males): 312 received cangrelor, 315 tirofiban. The percentage of history of bleeding, pulmonary edema and cardiogenic shock at admission was comparable between groups. Patients receiving cangrelor had lower ischemia time compared to tirofiban. TIMI flow before PPCI and TIMI thrombus grade were comparable between groups. At propensity score-weighted regression analysis, the risk of TIMI flow < 3 was significantly lower in patients treated with cangrelor compared to tirofiban (adjusted OR: 0.40; 95% CI: 0.30-0.53). The risk of BARC 2-5 bleeding was comparable between groups (adjusted OR:1.35; 95% CI: 0.92-1.98). These results were consistent across multiple prespecified subgroups, including subjects stratified for different total ischemia time, with no statistical interaction. In this real-world multicenter STEMI population, the use of cangrelor was associated with improved myocardial perfusion assessed by coronary angiography after PPCI without increasing clinically-relevant bleedings compared to tirofiban.

A real-world multicenter study on left atrial appendage occlusion: The Italian multi-device experience.

Background: Transcatheter left atrial appendage occlusion (LAAO) has emerged as an alternative treatment for stroke prevention in patients with atrial fibrillation (AF) at high risk of thromboembolism, who cannot tolerate long-term oral anticoagulation (OAC). Questions persist regarding effectiveness and safety of this treatment and the optimal post-interventional antithrombotic regimen after LAAO. Methods: We retrospectively gathered data from 428 patients who underwent percutaneous LAAO in 6 Italian high-volume centres, aimed at describing the real-world utilization, safety, and effectiveness of LAAO procedures, also assessing the clinical outcomes associated with different antithrombotic strategies. Results: Among the entire population, 20 (4.7 %) patients experienced a combination of pericardial effusion and periprocedural major bleeding: 8 (1.9 %) pericardial effusion, 1 (0.3 %) fatal bleeding, and 3 (0.7 %) non-fatal procedural major bleeding. Patients were discharged with different antithrombotic regimens: dual (DAPT) (27 %) or single (SAPT) (26 %) antiplatelet therapy, OAC (27 %), other antithrombotic regimens (14 %). Very few patients were not prescribed with antithrombotic drugs (6 %). At a medium 523 ± 58 days follow-up, 14 patients (3.3 %) experienced all-cause death, 6 patients (1.4 %) cardiovascular death, 3 patients (0.7 %) major bleeding, 10 patients (2.6 %) clinically relevant non-major bleeding, and 3 patients (0.7 %) ischemic stroke. At survival analysis, with DAPT as the reference group, OAC therapy was associated with better outcomes. Conclusions: Our findings confirm that LAAO is a safe procedure. Different individualized post-discharge antithrombotic regimens are now adopted, likely driven by the perceived thrombotic and hemorrhagic risk. The incidence of both ischemic and bleeding events tends to be low.

Effects of carbon-based conductive materials on semi-continuous anaerobic co-digestion of organic fraction of municipal solid waste and waste activated sludge.

Organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS) are the most produced organic waste streams in urban centres. Their anaerobic co-digestion (AcoD) allows to generate methane (CH4) and digestate employable as renewable energy source and soil amendment, respectively, fully in accordance with circular bioeconomy principles. However, the widespread adoption of such technology is limited by relatively low CH4 yields that fail to bridge the gap between benefits and costs. Among strategies to boost AcoD of OFMSW and WAS, use of conductive materials (CMs) to promote interspecies electron transfer has gained increasing attention. This paper presents one of the few experimental attempts of investigating the effects of four different carbon(C)-based CMs (i.e., granular activated carbon - GAC, graphite - GR, graphene oxide - GO, and carbon nanotubes - CNTs) separately added in semi-continuous AcoD of OFMSW and thickened WAS. The presence of C-based CMs has been observed to improve CH4 yield of the control process. Specifically, after 63 days of operation (concentrations of GAC and GR of 10.0 g/L and of GO and CNTs of 0.2 g/L), 0.186 NL/gVS, 0.191 NL/gVS, 0.203 NL/gVS, and 0.195 NL/gVS of CH4 were produced in reactors supplemented with GAC, GR, GO, and CNTs, respectively, compared to 0.177 NL/gVS produced in the control process. Likewise, at the end of the test (i.e., after 105 days at concentrations of C-based CMs half of the initial ones), CH4 yields were 0.193 NL/gVS, 0.201 NL/gVS, 0.211 NL/gVS, and 0.206 NL/gVS in reactors supplemented with GAC, GR, GO, and CNTs, respectively, compared to 0.186 NL/gVS of the control process. Especially with regard to GR, GO, and CNTs, results obtained in the present study represent a significant advance of the knowledge on the effects of such C-based CMs to realistic and scalable AD process conditions respect to previous literature.

[Optimizing the care management pathway of patients with ischemia and non-obstructive coronary arteries]. / Ottimizzazione del percorso clinico-gestionale del paziente con ischemia in assenza di malattia coronarica ostruttiva.

Ischemia with non-obstructive coronary arteries (INOCA) is defined by the coexistence of anginal symptoms and demonstrable ischemia, with no evidence of obstructive coronary arteries. The underlying mechanism of INOCA is coronary microvascular dysfunction with or without associated vasospasm. INOCA patients have recurrent symptoms, functional limitations, repeated access to the emergency department, impaired quality of life and a higher incidence of cardiovascular events than the general population. Although well described in chronic coronary syndrome guidelines, INOCA remains underdiagnosed in clinical practice because of insufficient awareness, lack of accurate diagnostic tools, and poorly standardized and consistent definitions to diagnose, both invasively and non-invasively, coronary microvascular dysfunction.To disseminate current scientific evidence on INOCA as a distinct clinical entity, during 2022 we conducted at 30 cardiology units all over the country a clinical practice improvement initiative, with the aim of developing uniform and shared management pathways for INOCA patients across different operational settings. The present document highlights the outcomes of this multidisciplinary initiative.

Ticagrelor or Clopidogrel Monotherapy vs Dual Antiplatelet Therapy After Percutaneous Coronary Intervention: A Systematic Review and Patient-Level Meta-Analysis.

Importance: Among patients undergoing percutaneous coronary intervention (PCI), it remains unclear whether the treatment efficacy of P2Y12 inhibitor monotherapy after a short course of dual antiplatelet therapy (DAPT) depends on the type of P2Y12 inhibitor. Objective: To assess the risks and benefits of ticagrelor monotherapy or clopidogrel monotherapy compared with standard DAPT after PCI. Data Sources: MEDLINE, Embase, TCTMD, and the European Society of Cardiology website were searched from inception to September 10, 2023, without language restriction. Study Selection: Included studies were randomized clinical trials comparing P2Y12 inhibitor monotherapy with DAPT on adjudicated end points in patients without indication to oral anticoagulation undergoing PCI. Data Extraction and Synthesis: Patient-level data provided by each trial were synthesized into a pooled dataset and analyzed using a 1-step mixed-effects model. The study is reported following the Preferred Reporting Items for Systematic Review and Meta-Analyses of Individual Participant Data. Main Outcomes and Measures: The primary objective was to determine noninferiority of ticagrelor or clopidogrel monotherapy vs DAPT on the composite of death, myocardial infarction (MI), or stroke in the per-protocol analysis with a 1.15 margin for the hazard ratio (HR). Key secondary end points were major bleeding and net adverse clinical events (NACE), including the primary end point and major bleeding. Results: Analyses included 6 randomized trials including 25 960 patients undergoing PCI, of whom 24 394 patients (12 403 patients receiving DAPT; 8292 patients receiving ticagrelor monotherapy; 3654 patients receiving clopidogrel monotherapy; 45 patients receiving prasugrel monotherapy) were retained in the per-protocol analysis. Trials of ticagrelor monotherapy were conducted in Asia, Europe, and North America; trials of clopidogrel monotherapy were all conducted in Asia. Ticagrelor was noninferior to DAPT for the primary end point (HR, 0.89; 95% CI, 0.74-1.06; P for noninferiority = .004), but clopidogrel was not noninferior (HR, 1.37; 95% CI, 1.01-1.87; P for noninferiority > .99), with this finding driven by noncardiovascular death. The risk of major bleeding was lower with both ticagrelor (HR, 0.47; 95% CI, 0.36-0.62; P < .001) and clopidogrel monotherapy (HR, 0.49; 95% CI, 0.30-0.81; P = .006; P for interaction = 0.88). NACE were lower with ticagrelor (HR, 0.74; 95% CI, 0.64-0.86, P < .001) but not with clopidogrel monotherapy (HR, 1.00; 95% CI, 0.78-1.28; P = .99; P for interaction = .04). Conclusions and Relevance: This systematic review and meta-analysis found that ticagrelor monotherapy was noninferior to DAPT for all-cause death, MI, or stroke and superior for major bleeding and NACE. Clopidogrel monotherapy was similarly associated with reduced bleeding but was not noninferior to DAPT for all-cause death, MI, or stroke, largely because of risk observed in 1 trial that exclusively included East Asian patients and a hazard that was driven by an excess of noncardiovascular death.