Balancing the risks of bleeding and stent thrombosis: a decision analytic model to compare durations of dual antiplatelet therapy after drug-eluting stents

Classification tree obtained by artificial intelligence for the prediction of heart failure after acute coronary syndromes

BACKGROUND

Coronary heart disease is the leading cause of heart failure (HF), and tools are needed to identify patients with a higher probability of developing HF after an acute coronary syndrome (ACS). Artificial intelligence (AI) has proven to be useful in identifying variables related to the development of cardiovascular complications.

METHODS

We included all consecutive patients discharged after ACS in two Spanish centers between 2006 and 2017. Clinical data were collected and patients were followed up for a median of 53months. Decision tree models were created by the model-based recursive partitioning algorithm.

RESULTS

The cohort consisted of 7,097 patients with a median follow-up of 53months (interquartile range: 18-77). The readmission rate for HF was 13.6% (964 patients). Eight relevant variables were identified to predict HF hospitalization time: HF at index hospitalization, diabetes, atrial fibrillation, glomerular filtration rate, age, Charlson index, hemoglobin, and left ventricular ejection fraction. The decision tree model provided 15 clinical risk patterns with significantly different HF readmission rates.

CONCLUSIONS

The decision tree model, obtained by AI, identified 8 leading variables capable of predicting HF and generated 15 differentiated clinical patterns with respect to the probability of being hospitalized for HF. An electronic application was created and made available for free.

Predictive Value of HAS-BLED and HEMORR2HAGES Bleeding Risk Scores After Percutaneous Coronary Intervention

BACKGROUND

Various scoring systems have been developed to assess the risk of bleeding in medical settings. HAS-BLED and HEMORR2HAGES risk scores are commonly used to estimate bleeding risk in patients receiving anticoagulation for atrial fibrillation, but data on their predictive value in patients undergoing percutaneous coronary intervention (PCI) are limited.

METHODS

This study evaluated and compared the predictive abilities of the HAS-BLED and HEMORR2HAGES bleeding risk scores in all-comer patients undergoing PCI. The PARIS score, specifically designed for patients undergoing PCI, was used as a comparator. The scores were calculated at baseline and compared with the occurrence of events during a 2-year clinical follow-up period. Between 2015 and 2017, all consecutive patients undergoing PCI we re prospectively enrolled and divided into risk tertiles based on bleeding risk scores. The primary end points were hierarchical major bleeding events, defined by Bleeding Academic Research Consortium types 3 through 5, and patient-oriented composite end points according to Bleeding Academic Research Consortium classification, which were assessed during the 2-year follow-up period.

RESULTS

A total of 1,080 patients completed the follow-up period. Two years after index, 189 patients (17.5%) had experienced any bleeding, with 48 events (4.4%) classified as Bleeding Academic Research Consortium types 3 to 5. All bleeding risk scores showed statistically significant predictive ability for bleeding events. The HEMORR2HAGES score (C statistic, 0.73) was more effective than the HAS-BLED score (C statistic, 0.66; P = .07) and the PARIS score (C statistic, 0.66; P = .06) in predicting risk of major bleeding. Patients in high-risk bleeding groups also experienced a higher incidence of patient-oriented composite end points.

CONCLUSIONS

The HEMORR2HAGES, HAS-BLED, and PARIS risk scores exhibited good predictive abilities for bleeding events following PCI. Patients at high risk of bleeding also demonstrated increased ischemic risk and higher mortality during the 2-year follow-up period.

Non-vitamin-K-antagonist oral anticoagulants (NOACs) after acute myocardial infarction: a network meta-analysis

BACKGROUND

Balancing the risk of bleeding and thrombosis after acute myocardial infarction (AMI) is challenging, and the optimal antithrombotic therapy remains uncertain. The potential of non-vitamin K antagonist oral anticoagulants (NOACs) to prevent ischaemic cardiovascular events is promising, but the evidence remains limited.

OBJECTIVES

To evaluate the efficacy and safety of non-vitamin-K-antagonist oral anticoagulants (NOACs) in addition to background antiplatelet therapy, compared with placebo, antiplatelet therapy, or both, after acute myocardial infarction (AMI) in people without an indication for anticoagulation (i.e. atrial fibrillation or venous thromboembolism).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, the Conference Proceedings Citation Index - Science, and two clinical trial registers in September 2022 with no language restrictions. We checked the reference lists of included studies for any additional trials.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) that evaluated NOACs plus antiplatelet therapy versus placebo, antiplatelet therapy, or both, in people without an indication for anticoagulation after an AMI.

DATA COLLECTION AND ANALYSIS

Two review authors independently checked the results of searches to identify relevant studies, assessed each included study, and extracted study data. We conducted random-effects pairwise analyses using Review Manager Web, and network meta-analysis using the R package 'netmeta'. We ranked competing treatments by P scores, which are derived from the P values of all pairwise comparisons and allow ranking of treatments on a continuous 0-to-1 scale.

MAIN RESULTS

We identified seven eligible RCTs, including an ongoing trial that we could not include in the analysis. Of the six RCTs involving 33,039 participants, three RCTs compared rivaroxaban with placebo, two RCTs compared apixaban with placebo, and one RCT compared dabigatran with placebo. All participants in the six RCTs received concomitant antiplatelet therapy. The available evidence suggests that rivaroxaban compared with placebo reduces the rate of all-cause mortality (risk ratio (RR) 0.82, 95% confidence interval (CI) 0.69 to 0.98; number needed to treat for an additional beneficial outcome (NNTB) 250; 3 studies, 21,870 participants; high certainty) and probably reduces cardiovascular mortality (RR 0.83, 95% CI 0.69 to 1.01; NNTB 250; 3 studies, 21,870 participants; moderate certainty). There is probably little or no difference between apixaban and placebo in all-cause mortality (RR 1.09, 95% CI 0.88 to 1.35; number needed to treat for an additional harmful outcome (NNTH) 334; 2 studies, 8638 participants; moderate certainty) and cardiovascular mortality (RR 0.99, 95% CI 0.77 to 1.27; number needed to treat not applicable; 2 studies, 8638 participants; moderate certainty). Dabigatran may reduce the rate of all-cause mortality compared with placebo (RR 0.57, 95% CI 0.31 to 1.06; NNTB 63; 1 study, 1861 participants; low certainty). Dabigatran compared with placebo may have little or no effect on cardiovascular mortality, although the point estimate suggests benefit (RR 0.72, 95% CI 0.34 to 1.52; NNTB 143; 1 study, 1861 participants; low certainty). Two of the investigated NOACs were associated with an increased risk of major bleeding compared to placebo: apixaban (RR 2.41, 95% CI 1.44 to 4.06; NNTH 143; 2 studies, 8544 participants; high certainty) and rivaroxaban (RR 3.31, 95% CI 1.12 to 9.77; NNTH 125; 3 studies, 21,870 participants; high certainty). There may be little or no difference between dabigatran and placebo in the risk of major bleeding (RR 1.74, 95% CI 0.22 to 14.12; NNTH 500; 1 study, 1861 participants; low certainty). The results of the network meta-analysis were inconclusive between the different NOACs at all individual doses for all primary outcomes. However, low-certainty evidence suggests that apixaban (combined dose) may be less effective than rivaroxaban and dabigatran for preventing all-cause mortality after AMI in people without an indication for anticoagulation.

AUTHORS' CONCLUSIONS

Compared with placebo, rivaroxaban reduces all-cause mortality and probably reduces cardiovascular mortality after AMI in people without an indication for anticoagulation. Dabigatran may reduce the rate of all-cause mortality and may have little or no effect on cardiovascular mortality. There is probably no meaningful difference in the rate of all-cause mortality and cardiovascular mortality between apixaban and placebo. Moreover, we found no meaningful benefit in efficacy outcomes for specific therapy doses of any investigated NOACs following AMI in people without an indication for anticoagulation. Evidence from the included studies suggests that rivaroxaban and apixaban increase the risk of major bleeding compared with placebo. There may be little or no difference between dabigatran and placebo in the risk of major bleeding. Network meta-analysis did not show any superiority of one NOAC over another for our prespecified primary outcomes. Although the evidence suggests that NOACs reduce mortality, the effect size or impact is small; moreover, NOACs may increase major bleeding. Head-to-head trials, comparing NOACs against each other, are required to provide more solid evidence.

Artificial Intelligence and Neurosurgery: Tracking Antiplatelet Response Patterns for Endovascular Intervention

Platelets play a critical role in blood clotting and the development of arterial blockages. Antiplatelet therapy is vital for preventing recurring events in conditions like coronary artery disease and strokes. However, there is a lack of comprehensive guidelines for using antiplatelet agents in elective neurosurgery. Continuing therapy during surgery poses a bleeding risk, while discontinuing it before surgery increases the risk of thrombosis. Discontinuation is recommended in neurosurgical settings but carries an elevated risk of ischemic events. Conversely, maintaining antithrombotic therapy may increase bleeding and the need for transfusions, leading to a poor prognosis. Artificial intelligence (AI) holds promise in making difficult decisions regarding antiplatelet therapy. This paper discusses current clinical guidelines and supported regimens for antiplatelet therapy in neurosurgery. It also explores methodologies like P2Y12 reaction units (PRU) monitoring and thromboelastography (TEG) mapping for monitoring the use of antiplatelet regimens as well as their limitations. The paper explores the potential of AI to overcome such limitations associated with PRU monitoring and TEG mapping. It highlights various studies in the field of cardiovascular and neuroendovascular surgery which use AI prediction models to forecast adverse outcomes such as ischemia and bleeding, offering assistance in decision-making for antiplatelet therapy. In addition, the use of AI to improve patient adherence to antiplatelet regimens is also considered. Overall, this research aims to provide insights into the use of antiplatelet therapy and the role of AI in optimizing treatment plans in neurosurgical settings.

Bleeding risk in patients prescribed dual antiplatelet therapy and triple therapy after coronary interventions: the ADAPTT retrospective population-based cohort studies

Background

Bleeding among populations undergoing percutaneous coronary intervention or coronary artery bypass grafting and among conservatively managed patients with acute coronary syndrome exposed to different dual antiplatelet therapy and triple therapy (i.e. dual antiplatelet therapy plus an anticoagulant) has not been previously quantified.

Objectives

The objectives were to estimate hazard ratios for bleeding for different antiplatelet and triple therapy regimens, estimate resources and the associated costs of treating bleeding events, and to extend existing economic models of the cost-effectiveness of dual antiplatelet therapy.

Design

The study was designed as three retrospective population-based cohort studies emulating target randomised controlled trials.

Setting

The study was set in primary and secondary care in England from 2010 to 2017.

Participants

Participants were patients aged ≥ 18 years undergoing coronary artery bypass grafting or emergency percutaneous coronary intervention (for acute coronary syndrome), or conservatively managed patients with acute coronary syndrome.

Data sources

Data were sourced from linked Clinical Practice Research Datalink and Hospital Episode Statistics.

Interventions

Coronary artery bypass grafting and conservatively managed acute coronary syndrome: aspirin (reference) compared with aspirin and clopidogrel. Percutaneous coronary intervention: aspirin and clopidogrel (reference) compared with aspirin and prasugrel (ST elevation myocardial infarction only) or aspirin and ticagrelor.

Main outcome measures

Primary outcome: any bleeding events up to 12 months after the index event. Secondary outcomes: major or minor bleeding, all-cause and cardiovascular mortality, mortality from bleeding, myocardial infarction, stroke, additional coronary intervention and major adverse cardiovascular events.

Results

The incidence of any bleeding was 5% among coronary artery bypass graft patients, 10% among conservatively managed acute coronary syndrome patients and 9% among emergency percutaneous coronary intervention patients, compared with 18% among patients prescribed triple therapy. Among coronary artery bypass grafting and conservatively managed acute coronary syndrome patients, dual antiplatelet therapy, compared with aspirin, increased the hazards of any bleeding (coronary artery bypass grafting: hazard ratio 1.43, 95% confidence interval 1.21 to 1.69; conservatively-managed acute coronary syndrome: hazard ratio 1.72, 95% confidence interval 1.15 to 2.57) and major adverse cardiovascular events (coronary artery bypass grafting: hazard ratio 2.06, 95% confidence interval 1.23 to 3.46; conservatively-managed acute coronary syndrome: hazard ratio 1.57, 95% confidence interval 1.38 to 1.78). Among emergency percutaneous coronary intervention patients, dual antiplatelet therapy with ticagrelor, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.47, 95% confidence interval 1.19 to 1.82), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.06, 95% confidence interval 0.89 to 1.27). Among ST elevation myocardial infarction percutaneous coronary intervention patients, dual antiplatelet therapy with prasugrel, compared with dual antiplatelet therapy with clopidogrel, increased the hazard of any bleeding (hazard ratio 1.48, 95% confidence interval 1.02 to 2.12), but did not reduce the incidence of major adverse cardiovascular events (hazard ratio 1.10, 95% confidence interval 0.80 to 1.51). Health-care costs in the first year did not differ between dual antiplatelet therapy with clopidogrel and aspirin monotherapy among either coronary artery bypass grafting patients (mean difference £94, 95% confidence interval -£155 to £763) or conservatively managed acute coronary syndrome patients (mean difference £610, 95% confidence interval -£626 to £1516), but among emergency percutaneous coronary intervention patients were higher for those receiving dual antiplatelet therapy with ticagrelor than for those receiving dual antiplatelet therapy with clopidogrel, although for only patients on concurrent proton pump inhibitors (mean difference £1145, 95% confidence interval £269 to £2195).

Conclusions

This study suggests that more potent dual antiplatelet therapy may increase the risk of bleeding without reducing the incidence of major adverse cardiovascular events. These results should be carefully considered by clinicians and decision-makers alongside randomised controlled trial evidence when making recommendations about dual antiplatelet therapy.

Limitations

The estimates for bleeding and major adverse cardiovascular events may be biased from unmeasured confounding and the exclusion of an eligible subgroup of patients who could not be assigned an intervention. Because of these limitations, a formal cost-effectiveness analysis could not be conducted.

Future work

Future work should explore the feasibility of using other UK data sets of routinely collected data, less susceptible to bias, to estimate the benefit and harm of antiplatelet interventions.

Trial registration

This trial is registered as ISRCTN76607611.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 8. See the NIHR Journals Library website for further project information.

Exploring the potential cost-effectiveness of a novel platelet assay for guiding dual antiplatelet therapy duration in acute coronary syndrome patients following percutaneous coronary intervention

OBJECTIVE

Duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) influences ischemic and bleeding events. Platelet expression of constant fragment of immunoglobulin, low affinity IIa, receptor (FcγRIIa) independently predicts risk of ischemic complications and is proposed as a tool to guide individualized care.

METHODS

We used a Markov model to predict lifetime ischemic and bleeding events and healthcare costs in acute myocardial infarction (MI) patients treated with PCI and DAPT and to project cost-effectiveness of platelet FcγRIIa-assay-guided care (30:3 months DAPT for patients at high: low ischemic risk) versus current standard care (12 months DAPT) from the perspective of the US healthcare system. Model inputs included assay sensitivity and specificity, ischemic and bleeding event rates, and impacts on quality of life, mortality, and costs. Assay cost was $90. Sensitivity analyses were conducted over a range of plausible clinical and cost assumptions.

RESULTS

Under base case assumptions, platelet FcγRIIa-assay-guided DAPT duration was projected to increase lifetime costs by $19 versus standard care, with an associated incremental cost-effectiveness ratio (ICER) of $436 per quality-adjusted life-year (QALY) gained. Assay-guided DAPT duration was consistent with high-value care (ICER < $50 000/QALY gained) over a broad range of alternative assumptions.

CONCLUSION

Based on a decision-analytic model, for patients with MI treated with PCI, the additional costs of the platelet FcγRIIa assay for guiding DAPT duration would be largely offset by reductions in downstream event-related costs, and assay-guided care would be highly cost-effective by current standards. These findings require confirmation in prospective studies and in a randomized clinical trial of assay-guided versus nonassay-guided DAPT duration.

Economic evaluation of deep brain stimulation compared with vagus nerve stimulation and usual care for patients with refractory epilepsy: A lifetime decision analytic model

OBJECTIVES

This study was undertaken to estimate the cost-effectiveness of deep brain stimulation (DBS) compared with vagus nerve stimulation (VNS) and care as usual (CAU) for adult patients with refractory epilepsy from a health care perspective using a lifetime decision analytic model.

METHODS

A Markov decision analytic model was constructed to estimate the lifetime cost-effectiveness of DBS compared with VNS and CAU. Transition probabilities were estimated from a randomized controlled trial, and assumptions were made in consensus with an expert panel. Primary outcomes were expressed as incremental costs per quality-adjusted life-year (QALY) and per responder. Univariate and probabilistic sensitivity analyses were conducted to characterize parameter uncertainty.

RESULTS

In DBS, 28.4% of the patients were responders, with an average of 21.38 QALYs per patient and expected lifetime health care costs of €187 791. VNS had fewer responders (22.3%), fewer QALYs (20.70), and lower lifetime costs (€156 871). CAU had the fewest responders (6.2%), fewest QALYs (18.74), and lowest total health care costs (€64 670). When comparing with CAU, incremental cost-effectiveness ratios (ICERs) showed that costs per QALY gained were slightly lower for DBS (€46 640) than for VNS (€47 155). When comparing DBS with VNS, an incremental cost per additional QALY gained of €45 170 was found for DBS. Sensitivity analyses showed that ICERs were heavily dependent on assumptions regarding loss to follow-up in the respective clinical trial.

SIGNIFICANCE

This study suggests that, given current limited evidence, VNS and DBS are potentially cost-effective treatment strategies compared to CAU for patients with refractory epilepsy. However, results for DBS were heavily impacted by assumptions made to extrapolate nonresponse from the original trial. More stringent assumptions regarding nonresponse resulted in an ICER just above an acceptable willingness to pay threshold. Given the uncertainty surrounding the effectiveness of DBS and the large impact of assumptions related to nonresponse, further empirical research is needed to reduce uncertainty.

Ischemic and Bleeding Outcomes According to the Academic Research Consortium High Bleeding Risk Criteria in All Comers Treated by Percutaneous Coronary Interventions

Background: The Academic Research Consortium have identified a set of major and minor risk factors in order to standardize the definition of a High Bleeding Risk (ACR-HBR). Aims: The aim of this study is to stratify the bleeding risk in patients included in the Cardio-Fribourg registry, according to the Academic Research Consortium for High Bleeding Risk (ACR-HBR) definition, and to report ischemic and hemorrhagic events at 2-year of clinical follow-up. Methods: Between 2015 and 2017, consecutive patients undergoing percutaneous coronary intervention were prospectively included in the Cardio-Fribourg registry. Patients were considered high (HBR) or low (LBR) bleeding risk depending on the ARC-HBR definition. Primary endpoints were hierarchical major bleeding events as defined by the Bleeding Academic Research Consortium (BARC) grade 3-5, and ARC patient-oriented major adverse cardiac events (POCE) at 2-year follow-up. Results: Follow-up was complete in 1,080 patients. There were 354 patients in the HBR group (32.7%) and 726 patients in the low-bleeding risk (LBR) group (67.2%). At 2-year follow-up, cumulative BARC 3-5 bleedings were higher in HBR (10.5%) compared to LBR patients (1.5%, p < 0.01) and the impact of HBR risk factors was incremental. At 2-year follow-up, POCE were more frequent in HBR (27.4%) compared to LBR group (18.2%, <0.01). Overall mortality was higher in HBR (14.0%) vs. LBR (2.9%, p < 0.01). Conclusions: ARC-HBR criteria appropriately identified a population at a higher risk of bleeding after percutaneous coronary intervention. An increased risk of bleeding is also associated with an increased risk of ischemic events at 2-year follow-up.

Weighing the potential late benefits versus early hazard associated with bioresorbable vascular scaffolds in percutaneous coronary interventions: a Markov decision analytic model

OBJECTIVE

Use of poly-L-lactic acid-based bioresorbable scaffolds (BRS) has been associated with increased risk of device thrombosis during the first 3 years after implantation as compared to metallic everolimus-eluting stents (EES). The long-term performance of BRS relative to EES remains unknown.

METHODS

We used a Markov decision analysis model to evaluate the effectiveness of BRS vs. EES over a lifetime horizon. In addition to one-way sensitivity analyses of key variables, we evaluated the impact of optimal implantation technique and limiting procedures to larger vessels (>2.6 mm in diameter) on model results.

RESULTS

Assuming no risk of target lesion revascularization for BRS after 3 years, we found a small increment in quality-adjusted life expectancy (QALE) of 0.02 with the use of BRS relative to EES, with benefit being observed after 21.8 years. Optimal implantation technique and limiting to larger vessels resulted in larger gains in QALE (0.08 and 0.06, respectively) with BRS and shorter times to equipoise (6.7 and 8.3 years, respectively). Model results were highly sensitive to variations in the relative risk of stent thrombosis (BRS vs. EES).

CONCLUSIONS

Based on currently available data, it would take approximately 21.8 years for the presumed late benefits of current BRS relative to EES to overcome the early hazard associated with their use under favorable assumptions. Optimal implantation technique and limiting procedures to larger vessels improved BRS performance and reduced time to equipoise. Eliminating the higher BRS thrombosis risk is necessary in developing future generations of BRS as an acceptable alternative to EES.

The Development of Magnesium-Based Resorbable and Iron-Based Biocorrodible Metal Scaffold Technology and Biomedical Applications in Coronary Artery Disease Patients

In the treatment of atherosclerotic disease patients, the adoption of second-generation drug-eluting stents (DES) in percutaneous coronary intervention reduced the occurrence of in-stent restenosis (ISR) and acute stent thrombosis (ST) when compared to bare metal stents and 1st generation DES. However, the permanent encaging of the vessel wall by any of the metallic stents perpetuates the inflammation process and prevents vasomotion in the treated segment. Aiming to overcome this issue, the bioresorbable scaffold (BRS) concept was developed by providing transient vascular radial support to the target segment during the necessary time to heal and disappearing after a period of time. Close to 20 years since BRS technology was first reported, the interventional cardiology field saw the rise and fall of several BRS devices. Although iron-based BRS is an emerging technology, currently, magnesium-alloy resorbable scaffolds devices are supported with the most robust data. This manuscript aims to review the concept of magnesium-based BRS devices, as well as their bioresorption mechanisms and the status of this technology, and the clinical outcomes of patients treated with magnesium BRS and to review the available evidence on iron-based BRS technology.

Impact of Clopidogrel Therapy on Mortality and Cancer in Patients With Cardiovascular and Cerebrovascular Disease: A Patient-Level Meta-Analysis

BACKGROUND

Clinical trial data associate extended clopidogrel therapy with increased mortality and cancer. We sought to determine the impact of continued clopidogrel use on mortality and cancer within a patient-level meta-analysis of randomized clinical trials.

METHODS AND RESULTS

Meta-analytic clinical event rates for all-cause, cardiovascular, noncardiovascular, and cancer-related mortality; cancer; myocardial infarction; stroke; and fatal and major nonfatal bleeding were generated using patient-level data from 6 randomized trials comparing prolonged versus no or short-duration clopidogrel on a background of aspirin in patients with cardiovascular and cerebrovascular disease. Among 48 817 randomized patients (median follow-up 546 days), there was no difference in all-cause (7.23% versus 7.26%; P=0.97), cardiovascular (5.25% versus 5.22%; P=0.86), noncardiovascular (1.98% versus 2.03%; P=0.73), and cancer-related (0.93% versus 0.99%; P=0.59) mortality or in new cancer diagnoses (2.97% versus 2.96%; P>0.99). Rates of myocardial infarction (3.21% versus 4.05%; P<0.0001) and stroke (3.04% versus 3.75%; P<0.0001) were significantly lower in patients receiving continued clopidogrel. Fatal bleeding was more common with continued clopidogrel use (0.39% versus 0.27%; P=0.03), as were major nonfatal bleeding (4.06% versus 2.68%; P<0.0001) and intracranial hemorrhage (0.43% versus 0.30%; P=0.02).

CONCLUSIONS

Across trials of cardiovascular and cerebrovascular disease, extended-duration clopidogrel on a background of aspirin has no overall effect on mortality or cancer but does reduce rates of myocardial infarction and stroke and increase rates of bleeding. These findings emphasize the need for selective use of extended clopidogrel therapy in patients in whom the risks of ischemia are not fully counterbalanced by the risks of bleeding.

Effects of Cangrelor as Adjunct Therapy to Percutaneous Coronary Intervention

Percutaneous coronary intervention (PCI) in patients with angiographic evidence of intracoronary thrombus is associated with in-hospital and 30-day adverse clinical outcomes. Cangrelor, a direct, rapid-onset acting intravenous P2Y₁₂ receptor inhibitor, has been proved to be effective by reducing peri-PCI ischemic complications in subjects who underwent PCI. This study aimed to assess the angiographic and in-hospital clinical outcomes in all-comer patients receiving cangrelor immediately before PCI at a tertiary care center. The study analyzed consecutive unselected subjects treated with cangrelor at the time the decision was made to proceed with PCI. At the end of the procedure, all patients were transitioned to oral antiplatelet therapy. The target lesion angiographic assessment of Thrombolysis in myocardial infarction flow grade (TIMI-Flow), TIMI-thrombus grade (TIMI-Thrombus), myocardial blush grade, and TIMI-myocardial perfusion grade (TMPG) was performed before and post-PCI. Clinical events were recorded during the procedure and at discharge. In total, 223 patients (244 lesions) were included in the analysis (106, 97, and 20 patientswith TIMI-Flow 0/1, TIMI-Flow 2/3, and cardiogenic shock, respectively). The overall mean age was 63 ± 12 years, 70% men and 38% with diabetes mellitus. Acute myocardial infarction was the main presentation (72%). The use of cangrelor improved TIMI-Flow, MGB, TMPG, and TIMI-Thrombus in patients with initial TIMI-Flow 0 to 2. Major bleeding rate was 2.0%. In conclusion, cangrelor was effective and safe in restoring TIMI-Flow 3, reducing thrombus burden and improving myocardial blush grade and TMPG when administered to unselected subjects who underwent PCI. Therefore, cangrelor should be considered in patients presenting with intracoronary thrombus before intervention.

Cost-effectiveness analysis of short-duration dual antiplatelet therapy with newer drug-eluting stent platforms versus longer-duration dual antiplatelet therapy with a second-generation drug-eluting stent in elective percutaneous coronary intervention

BACKGROUND

The cost-effectiveness of newer drug-eluting stents (DES) such as biodegradable-polymer or polymer-free stents with shorter dual antiplatelet therapy (DAPT) duration is unknown. We evaluated the cost-effectiveness of treatment with newer DES that may allow for shorter DAPT duration.

PATIENTS AND METHODS

We performed a cost-effectiveness analysis of treatment with newer DES platforms followed by 1 or 3 months of DAPT compared with standard second-generation DES followed by 6 or 12 months of DAPT in patients with stable coronary disease. A Markov model simulated distinct health states over a lifetime. Probabilistic sensitivity analysis and one-way sensitivity analyses were performed. A high-risk bleeding scenario was also evaluated.

RESULTS

Among patients with typical bleeding risk, second-generation DES and 6 months of DAPT was less expensive and resulted in marginally higher quality-adjusted life years compared with other strategies. A newer DES platform and 3 months of DAPT was preferred when the risk of fatal bleeding was two times greater than baseline, or when bleeding increased long-term mortality by a factor of 1.5. In a probabilistic sensitivity analysis, second-generation DES and 6 months of DAPT was preferred in 58% of iterations, whereas in a high-risk bleeding patient scenario, a newer DES and 3 months of DAPT was preferred in 52% of iterations.

CONCLUSION

A DES that allows 3 months of DAPT without increasing stent-related events is likely to be cost-effective among patients at elevated risk of bleeding, but not in patients with average bleeding risk.

Oral Antiplatelet Therapy for Secondary Prevention of Acute Coronary Syndrome

Patients surviving an acute coronary syndrome (ACS) remain at increased risk of ischemic events long term. This paper reviews current evidence and guidelines for oral antiplatelet therapy for secondary prevention following ACS, with respect to decreased risk of ischemic events versus bleeding risk according to individual patient characteristics and risk factors. Specifically, data are reviewed from clinical studies of clopidogrel, prasugrel, ticagrelor and vorapaxar, as well as the results of systematic reviews and meta-analyses looking at the benefits and risks of oral antiplatelet therapy, and the relative merits of shorter versus longer duration of dual antiplatelet therapy, in different patient groups.

Health-related quality of life impact of minor and major bleeding events during dual antiplatelet therapy: a systematic literature review and patient preference elicitation study

Background

Dual antiplatelet therapy (DAPT) is the recommended preventative treatment for secondary ischaemic events, but increases the risk of bleeding, potentially affecting patients’ health-related quality-of-life (HRQoL). Varied utility decrements have been used in cost-effectiveness models assessing alternative DAPT regimens, but it is unclear which of these decrements are most appropriate. Therefore, we reviewed existing sources of utility decrements for bleeds in patients receiving DAPT and undertook primary research to estimate utility decrements through a patient elicitation exercise using vignettes and the EuroQol EQ-5D.

Methods

MEDLINE, PubMed and references of included studies were searched. Primary research and decision analytic modelling studies reporting utility decrements for bleeds related to DAPT were considered. For the primary research study, 21 participants completed an elicitation exercise involving vignettes describing minor and major bleeds and the EQ-5D-3 L and EQ-5D-5 L. Utility decrements were derived using linear regression and compared to existing estimates.

Results

Four hundred forty-two citations were screened, of which 12 studies were included for review. Reported utility decrements ranged from − 0.002 to − 0.03 for minor bleeds and − 0.007 to − 0.05 for major bleeds. Data sources used to estimate the decrements, however, lacked relevance to our population group and few studies adequately reported details of their measurement and valuation approaches. No study completely adhered to reimbursement agency requirements in the UK according to the National Institute for Health and Care Excellence reference case. Our primary research elicited utility decrements overlapped existing estimates, ranging from − 0.000848 to − 0.00828 for minor bleeds and − 0.0187 to − 0.0621 for major bleeds. However, the magnitude of difference depended on the instrument, estimation method and valuation approach applied.

Conclusions

Several sources of utility decrements for bleeds are available for use in cost-effectiveness analyses, but are of limited quality and relevance. Our elicitation exercise has derived utility decrements from a relevant patient population, based on standardised definitions of minor and major bleeding events, using a validated HRQoL instrument and have been valued using general population tariffs. We suggest that our utility decrements be used in future cost-effectiveness analyses of DAPT.

Electronic supplementary material

The online version of this article (10.1186/s12955-018-1019-3) contains supplementary material, which is available to authorized users.

Decision Analytic Markov Model Weighting Expected Benefits and Current Limitations of First-Generation Bioresorbable Vascular Scaffolds: Implications for Manufacturers and Next Device Iterations

BACKGROUND

Relative benefits of bioresorbable vascular scaffolds (BVS) compared with everolimus-eluting stents (EES) are expected to accrue after complete bioresorption.

METHODS AND RESULTS

We built a decision analytic Markov model comparing BVS and EES for a contemporary percutaneous coronary intervention population. Procedure-related morbidity and outcome data from the available literature were used to derive model probabilities. The net benefit of BVS and EES was estimated in terms of quality-adjusted life expectancy. Under the assumption of no risk for device thrombosis and target lesion revascularization with BVS beyond 3 years, the equipoise in quality-adjusted life expectancy (12.86) between BVS and EES was achieved 19 years after implantation. The maximum tolerable excess risk of 3-year BVS thrombosis equalizing the model-predicted quality-adjusted life expectancy of BVS and EES at 10 years was 1.40, corresponding to an absolute tolerable rate of 1.45%.

CONCLUSIONS

At the currently observed relative increase in device thrombosis and under the extreme hypothesis of no scaffold thrombosis and target lesion revascularization beyond 3 years, the incremental benefit of BVS over EES becomes apparent only after 19 years. This simulation suggests that there is a small degree of benefit that clinicians and decision-makers may expect from the first-generation BVS at the current risk of device thrombosis. Manufacturers should target scaffold thrombosis rates <1.45% at 3 years to make their technologies attractive during a 10-year horizon.

Cost-effectiveness analysis of 30-month vs 12-month dual antiplatelet therapy with clopidogrel and aspirin after drug-eluting stents in patients with acute coronary syndrome

Continuation of dual antiplatelet therapy (DAPT) beyond 1 year reduces late stent thrombosis and ischemic events after drug-eluting stents (DES) but increases risk of bleeding. We hypothesized that extending DAPT from 12 months to 30 months in patients with acute coronary syndrome (ACS) after DES is cost-effective. A lifelong decision-analytic model was designed to simulate 2 antiplatelet strategies in event-free ACS patients who had completed 12-month DAPT after DES: aspirin monotherapy (75-162 mg daily) and continuation of DAPT (clopidogrel 75 mg daily plus aspirin 75-162 mg daily) for 18 months. Clinical event rates, direct medical costs, and quality-adjusted life-years (QALYs) gained were the primary outcomes from the US healthcare provider perspective. Base-case results showed DAPT continuation gained higher QALYs (8.1769 vs 8.1582 QALYs) at lower cost (USD42 982 vs USD44 063). One-way sensitivity analysis found that base-case QALYs were sensitive to odds ratio (OR) of cardiovascular death with DAPT continuation and base-case cost was sensitive to OR of nonfatal stroke with DAPT continuation. DAPT continuation remained cost-effective when the ORs of nonfatal stroke and cardiovascular death were below 1.241 and 1.188, respectively. In probabilistic sensitivity analysis, DAPT continuation was the preferred strategy in 74.75% of 10 000 Monte Carlo simulations at willingness-to-pay threshold of 50 000 USD/QALYs. Continuation of DAPT appears to be cost-effective in ACS patients who were event-free for 12-month DAPT after DES. The cost-effectiveness of DAPT for 30 months was highly subject to the OR of nonfatal stroke and OR of death with DAPT continuation.

Personalising the decision for prolonged dual antiplatelet therapy: development, validation and potential impact of prognostic models for cardiovascular events and bleeding in myocardial infarction survivors

Aims

The aim of this study is to develop models to aid the decision to prolong dual antiplatelet therapy (DAPT) that requires balancing an individual patient's potential benefits and harms.

Methods and results

Using population-based electronic health records (EHRs) (CALIBER, England, 2000-10), of patients evaluated 1 year after acute myocardial infarction (MI), we developed (n = 12 694 patients) and validated (n = 5613) prognostic models for cardiovascular (cardiovascular death, MI or stroke) events and three different bleeding endpoints. We applied trial effect estimates to determine potential benefits and harms of DAPT and the net clinical benefit of individuals. Prognostic models for cardiovascular events (c-index: 0.75 (95% CI: 0.74, 0.77)) and bleeding (c index 0.72 (95% CI: 0.67, 0.77)) were well calibrated: 3-year risk of cardiovascular events was 16.5% overall (5.2% in the lowest- and 46.7% in the highest-risk individuals), while for major bleeding, it was 1.7% (0.3% in the lowest- and 5.4% in the highest-risk patients). For every 10 000 patients treated per year, we estimated 249 (95% CI: 228, 269) cardiovascular events prevented and 134 (95% CI: 87, 181) major bleeding events caused in the highest-risk patients, and 28 (95% CI: 19, 37) cardiovascular events prevented and 9 (95% CI: 0, 20) major bleeding events caused in the lowest-risk patients. There was a net clinical benefit of prolonged DAPT in 63-99% patients depending on how benefits and harms were weighted.

Conclusion

Prognostic models for cardiovascular events and bleeding using population-based EHRs may help to personalise decisions for prolonged DAPT 1-year following acute MI.

Genetic Polymorphism of CYP2C19 and Inhibitory Effects of Ticagrelor and Clopidogrel Towards Post-Percutaneous Coronary Intervention (PCI) Platelet Aggregation in Patients with Acute Coronary Syndromes

Background

The aim of this study was to observe the effects of genetic polymorphism of CYP2C19 on inhibitory effects of ticagrelor (Tic) and clopidogrel (Clo) towards post-percutaneous coronary intervention (PCI) platelet aggregation (IPA) and major cardiovascular events (MACE) in patients with acute coronary syndromes (ACS).

Material/Methods

From August 2013 to March 2014, 166 patients with ACS undergoing PCI were selected. The patients were randomly grouped into the Tic group and the Clo group. IPA was detected by thromboelastography (TEG) at 1 week after taking the pills. Genotyping of CYP2C19 gene was determined by analysis of gene sequence detection. Patients were followed up for 1 month and MACE was observed.

Results

The total IPA in the Clo group was significantly increased compared with the Tic group (P<0.05). The IPAs in the 3 subgroups of Clo group were all significantly increased compared with the 3 subgroups of the Tic group (all P<0.05). MACE was not significantly different between Clo and Tic groups (P>0.05). MACE had no significant difference among the 3 subgroups of the Tic group (P>0.05). MACE in the low metabolism subgroup of the Clo group was significantly increased compared with the fast metabolism subgroup and middle metabolism subgroup of Clo group (P<0.05). MACE was not significant different between the fast metabolism subgroup and the middle metabolism subgroup of the Clo group (P>0.05). MACE in the low metabolism subgroup of the Tic group was significantly decreased compared with the low metabolism subgroup of the Clo group (P<0.05).

Conclusions

Ticagrelor has a better effect on inhibition platelet aggregation than Clopidogrel in ACS patients undergoing PCI.

Extended duration dual antiplatelet therapy in patients with myocardial infarction: A study-level meta-analysis of controlled randomized trials

BACKGROUND

Whether dual antiplatelet therapy (DAPT) is beneficial beyond 1 year after myocardial infarction (MI) is not demonstrated; in particular, available studies may be individually underpowered for end points at low incidence, that is, major and fatal bleeding or mortality. We thus assessed the effectiveness and safety of prolonged DAPT after MI over the long term.

METHODS

We conducted a systematic search to identify randomized trials on the topic; 3 studies and 21,534 post-MI patients receiving placebo or aspirin plus P2Y12 inhibition for ≥2 years were included. Incidence of the following outcome measures was evaluated: major adverse cardiac events (MACE), major bleeding, fatal bleeding, and cardiovascular and noncardiovascular death.

RESULTS

Occurrence of MACE was lower in patients treated with prolonged DAPT: 6.3% vs 7.9% in those without prolonged DAPT (odds ratios 0.74, 95% CI 0.60-0.91, P = .005); in the former, there was also a significant 16% reduction in cardiovascular mortality. Increase in major bleeding with extended duration DAPT was not significant in the overall analysis (1.5% vs 1.0%; P = .10), but became significant in the analysis restricted to patients receiving ticagrelor or prasugrel as second antiplatelet agent (odds ratios 2.16, 95% CI 1.63-2.86); prolonged use of DAPT did not raise rates of fatal bleeding or noncardiovascular mortality.

CONCLUSION

Prolonged DAPT after MI reduces MACE and cardiovascular mortality over the long term; this was paralleled by higher risk of nonfatal major bleeding mainly with the newer, more potent P2Y12 antagonists. Tailoring duration of DAPT after MI on the comparative evaluation of both ischemic and bleeding risk is mandatory in this setting.

Optimal duration of dual antiplatelet therapy after coronary stent implantation

Dual antiplatelet pharmacotherapy reduces ischemic events at the cost of excess bleeding in patients who underwent coronary stenting. The currently recommended treatment period is based on trials held some 20 years ago and not relevant to current clinical practice. In recent years, numerous clinical trials have tried to answer the question of what is the optimal duration of therapy to maximize clinical benefit. These trials showed 2 seemingly conflicting answers-on one hand, shorter treatment duration seems to be safer in reducing bleeding while not increasing ischemic events, and on the other hand, longer duration is superior in terms of preventing ischemic events albeit at the cost of increased bleeding rates. In this review, we summarize the evidence favoring each approach, highlight the limitations of the various pivotal clinical trials in this field, review future directions of research and changes in practice that may influence the duration of antiplatelet therapy, and attempt to propose a personalized approach to achieve maximal benefit for the individual patient.

Balancing Long-Term Risks of Ischemic and Bleeding Complications After Percutaneous Coronary Intervention With Drug-Eluting Stents

Although trials comparing antiplatelet strategies after percutaneous coronary intervention report average risks of bleeding and ischemia in a population, there is limited information to guide choices based on individual patient risks, particularly beyond 1 year after treatment. Patient-level data from Patient Related Outcomes With Endeavor vs Cypher Stenting Trial (PROTECT), a broadly inclusive trial enrolling 8,709 subjects treated with drug-eluting stents (sirolimus vs zotarolimus-eluting stent), and PROTECT US, a single-arm study including 1,018 subjects treated with a zotarolimus-eluting stent, were combined. The risk of ischemic events, cardiovascular death/non-periprocedural myocardial infarction (MI)/definite or probable stent thrombosis, and bleeding events, Global Use of Strategies to Open Occluded Arteries moderate or severe bleed, were predicted using logistic regression. At median follow-up of 4.1 years, major bleeding occurred in 260 subjects (2.8%) and ischemic events in 595 (6.3%). Multivariate predictors of bleeding were older age, smoking, diabetes mellitus, congestive heart failure, and chronic kidney disease (all p <0.05). Ischemic events shared all the same predictors with bleeding events and gender, body mass index, previous MI, previous coronary artery bypass graft surgery, ST-segment elevation MI on presentation, stent length, and sirolimus-eluting stent use (all p <0.05). Within individual subjects, bleeding and ischemic risks were strongly correlated; 97% of subjects had a greater risk of ischemic events than bleeding. In conclusion, individual patient risks of ischemia and bleeding are related to many common risk factors, yet the predicted risks of ischemic events are greater than those of major bleeding in the large majority of patients in long-term follow-up.

Optimal Duration of Dual Antiplatelet Therapy After DES Implantation: A Meta-Analysis of 11 Randomized Trials

Despite new-generations of drug-eluting stents (DESs), the optimal duration of dual antiplatelet therapy (DAPT) remains controversial. We performed a meta-analysis of randomized trials (RTs) evaluating the effectiveness and safety of shorter versus longer DAPT duration strategies in patients undergoing percutaneous coronary interventions with DES. Literature and main scientific session abstracts were searched. The primary end point was mortality. Secondary end points were (1) cardiovascular mortality, (2) nonfatal myocardial infarction, (3) definite/probable stent thrombosis (ST), and (4) major bleedings. We included 11 RTs (n = 32 372 patients). Shorter DAPT duration reduced mortality (odds ratio, OR [95% confidence interval, CI] = 0.85 [0.71-1], P = .05; p heterogeneity = 0.91). Similar results were observed when comparing 3 to 6 versus 12 months DAPT, while a significant increase in recurrent ischemic events was found for 6 to 12 months DAPT versus extended treatment (myocardial infarction: OR [95%CI] = 1.66 [1.37-2], P < .00001; phet = 0.13 and ST: OR [95%CI] = 2.47 [1.72-3.45], P < .00001; phet = 0.12), however, counterbalanced by a significant reduction in major bleeding (OR [95%CI] = 0.60 [0.47-0.76], P < .0001; phet = 0.38) and a trend in lower mortality. Thus, among selected patients undergoing DES implantation, a shorter DAPT strategy is associated with reduction in mortality and major bleeding but a higher risk of myocardial infarction and ST. A short duration (3-6 months) of DAPT appears as the safest strategy, while a prolonged duration (24-36 months) reduces thrombotic complications but with an excess in major bleeding complications.

Benefits and Risks of Extended Duration Dual Antiplatelet Therapy After PCI in Patients With and Without Acute Myocardial Infarction

BACKGROUND

The benefits and risks of prolonged dual antiplatelet therapy may be different for patients with acute myocardial infarction (MI) compared with more stable presentations.

OBJECTIVES

This study sought to assess the benefits and risks of 30 versus 12 months of dual antiplatelet therapy among patients undergoing coronary stent implantation with and without MI.

METHODS

The Dual Antiplatelet Therapy Study, a randomized double-blind, placebo-controlled trial, compared 30 versus 12 months of dual antiplatelet therapy after coronary stenting. The effect of continued thienopyridine on ischemic and bleeding events among patients initially presenting with versus without MI was assessed. The coprimary endpoints were definite or probable stent thrombosis and major adverse cardiovascular and cerebrovascular events (MACCE). The primary safety endpoint was GUSTO (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Arteries) moderate or severe bleeding.

RESULTS

Of 11,648 randomized patients (9,961 treated with drug-eluting stents, 1,687 with bare-metal stents), 30.7% presented with MI. Between 12 and 30 months, continued thienopyridine reduced stent thrombosis compared with placebo in patients with and without MI at presentation (MI group, 0.5% vs. 1.9%, p < 0.001; no MI group, 0.4% vs. 1.1%, p < 0.001; interaction p = 0.69). The reduction in MACCE for continued thienopyridine was greater for patients with MI (3.9% vs. 6.8%; p < 0.001) compared with those with no MI (4.4% vs. 5.3%; p = 0.08; interaction p = 0.03). In both groups, continued thienopyridine reduced MI (2.2% vs. 5.2%, p < 0.001 for MI; 2.1% vs. 3.5%, p < 0.001 for no MI; interaction p = 0.15) but increased bleeding (1.9% vs. 0.8%, p = 0.005 for MI; 2.6% vs. 1.7%, p = 0.007 for no MI; interaction p = 0.21).

CONCLUSIONS

Compared with 12 months of therapy, 30 months of dual antiplatelet therapy reduced the risk of stent thrombosis and MI in patients with and without MI, and increased bleeding. (The Dual Antiplatelet Therapy Study [The DAPT Study]; NCT00977938).

Twelve or 30 months of dual antiplatelet therapy after drug-eluting stents

BACKGROUND

Dual antiplatelet therapy is recommended after coronary stenting to prevent thrombotic complications, yet the benefits and risks of treatment beyond 1 year are uncertain.

METHODS

Patients were enrolled after they had undergone a coronary stent procedure in which a drug-eluting stent was placed. After 12 months of treatment with a thienopyridine drug (clopidogrel or prasugrel) and aspirin, patients were randomly assigned to continue receiving thienopyridine treatment or to receive placebo for another 18 months; all patients continued receiving aspirin. The coprimary efficacy end points were stent thrombosis and major adverse cardiovascular and cerebrovascular events (a composite of death, myocardial infarction, or stroke) during the period from 12 to 30 months. The primary safety end point was moderate or severe bleeding.

RESULTS

A total of 9961 patients were randomly assigned to continue thienopyridine treatment or to receive placebo. Continued treatment with thienopyridine, as compared with placebo, reduced the rates of stent thrombosis (0.4% vs. 1.4%; hazard ratio, 0.29 [95% confidence interval {CI}, 0.17 to 0.48]; P<0.001) and major adverse cardiovascular and cerebrovascular events (4.3% vs. 5.9%; hazard ratio, 0.71 [95% CI, 0.59 to 0.85]; P<0.001). The rate of myocardial infarction was lower with thienopyridine treatment than with placebo (2.1% vs. 4.1%; hazard ratio, 0.47; P<0.001). The rate of death from any cause was 2.0% in the group that continued thienopyridine therapy and 1.5% in the placebo group (hazard ratio, 1.36 [95% CI, 1.00 to 1.85]; P=0.05). The rate of moderate or severe bleeding was increased with continued thienopyridine treatment (2.5% vs. 1.6%, P=0.001). An elevated risk of stent thrombosis and myocardial infarction was observed in both groups during the 3 months after discontinuation of thienopyridine treatment.

CONCLUSIONS

Dual antiplatelet therapy beyond 1 year after placement of a drug-eluting stent, as compared with aspirin therapy alone, significantly reduced the risks of stent thrombosis and major adverse cardiovascular and cerebrovascular events but was associated with an increased risk of bleeding. (Funded by a consortium of eight device and drug manufacturers and others; DAPT ClinicalTrials.gov number, NCT00977938.).