Association of Coronary Anatomical Complexity With Clinical Outcomes After Percutaneous or Surgical Revascularization in the Veterans Affairs Clinical Assessment Reporting and Tracking Program

Sex Disparities in the Management of Acute Coronary Syndromes: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

BACKGROUND

Previous work has demonstrated disparities in the management of cardiovascular disease among men and women. We sought to evaluate these disparities and their associations with clinical outcomes among patients admitted with acute coronary syndromes to the Veterans Affairs Healthcare System.

METHODS AND RESULTS

We identified all patients that were discharged with acute coronary syndromes within the Veterans Affairs Healthcare System from October 1, 2015 to September 30, 2022. Medical and procedural management of patients was subsequently assessed, stratified by sex. In doing so, we identified 76 454 unique admissions (2327 women, 3.04%), which after propensity matching created an analytic cohort composed of 6765 men (74.5%) and 2295 women (25.3%). Women admitted with acute coronary syndromes were younger with fewer cardiovascular comorbidities and a lower prevalence of preexisting prescriptions for cardiovascular medications. Women also had less coronary anatomic complexity compared with men (5 versus 8, standardized mean difference [SMD]=0.40), as calculated by the Veterans Affairs SYNTAX score. After discharge, women were significantly less likely to receive cardiology follow-up at 30 days (hazard ratio [HR], 0.858 [95% CI, 0.794-0.928]) or 1 year (HR, 0.891 [95% CI, 0.842-0.943]), or receive prescriptions for guideline-indicated cardiovascular medications. Despite this, 1-year mortality rates were lower for women compared with men (HR, 0.841 [95% CI, 0.747-0.948]).

CONCLUSIONS

Women are less likely to receive appropriate cardiovascular follow-up and medication prescriptions after hospitalization for acute coronary syndromes. Despite these differences, the clinical outcomes for women remain comparable. These data suggest an opportunity to improve the posthospitalization management of cardiovascular disease regardless of sex.

Real-World Experience and Outcomes With Percutaneous Coronary Intervention for Protected Versus Unprotected Left Main Coronary Artery Disease: Insights from the Veteran Affairs Clinical Assessment Reporting and Tracking Program

The practice patterns and outcomes of protected left main (PLM) and unprotected left main (ULM) percutaneous coronary intervention (PCI) are not well defined in contemporary US clinical practice. Data were collected from all Veteran Affairs catheterization laboratories participating in the Clinical Assessment Reporting and Tracking Program between 2009 and 2019. The analysis included 4,351 patients who underwent left main PCI, of whom 1,306 pairs of PLM and ULM PCI were included in a propensity-matched cohort. Selected temporal trends were also assessed. The primary outcome was major adverse cardiovascular event (MACE) outcomes at 1 year, which was defined as a composite of all-cause mortality, rehospitalization for myocardial infarction (MI), rehospitalization for stroke, or urgent revascularization. Patients who underwent ULM PCI compared with patients who underwent PLM PCI were older (age 71.5 vs 69.2 years, p <0.001), more clinically complex, and more likely to present with acute coronary syndrome. In the propensity-matched cohort, radial access was used more often for ULM PCI (21% [273] vs 14% [185], p <0.001) and ULM PCI was more likely to involve the left main bifurcation (22% vs 14%, p = 0.003) and require mechanical circulatory support (10% [134] vs 1% [17], p <0.001). The 1-year MACEs occurred more frequently with ULM PCI than PLM PCI (22% [289] vs 16% [215], p ≤0.001) and all-cause mortality was also higher (16% [213] vs 10% [125], p ≤0.001). In the matched cohort, there was a low incidence of rehospitalization for MI (4% [48] ULM vs 4% [48] PLM, p = 1.000) or revascularization (7% [94] ULM vs 6% [84] PLM, p = 0.485). In this real-world experience, patients who underwent PLM PCI had better 1-year outcomes than those who underwent ULM PCI; however, in both groups, there was a high rate of mortality and MACEs at 1 year despite a relatively low rate of MI or revascularization.

Contemporary Risk Models for In-Hospital and 30-Day Mortality After Percutaneous Coronary Intervention

PURPOSE OF REVIEW

Risk models for mortality after percutaneous coronary intervention (PCI) are underutilized in clinical practice though they may be useful during informed consent, risk mitigation planning, and risk adjustment of hospital and operator outcomes. This review analyzed contemporary risk models for in-hospital and 30-day mortality after PCI.

RECENT FINDINGS

We reviewed eight contemporary risk models. Age, sex, hemodynamic status, acute coronary syndrome type, heart failure, and kidney disease were consistently found to be independent risk factors for mortality. These models provided good discrimination (C-statistic 0.85-0.95) for both pre-catheterization and comprehensive risk models that included anatomic variables. There are several excellent models for PCI mortality risk prediction. Choice of the model will depend on the use case and population, though the CathPCI model should be the default for in-hospital mortality risk prediction in the United States. Future interventions should focus on the integration of risk prediction into clinical care.

Outcomes of Percutaneous Coronary Intervention for Protected versus Unprotected Left Main Coronary Artery Disease: Insights from the VA CART Program

Background

Practice patterns and outcomes of protected left main (PLM) and unprotected left main (ULM) percutaneous coronary intervention (PCI), as well as the differences between these types of PCI, are not well defined in real-world clinical practice.

Methods

Data collected from all Veteran Affairs (VA) catheterization laboratories participating in the Clinical Assessment Reporting and Tracking Program between 2009 and 2019. The analysis included 4,351 patients undergoing left main PCI, of which 1,306 pairs of PLM and ULM PCI were included in a propensity matched cohort. Patients and procedural characteristics were compared between PLM and ULM PCI. Temporal trends were also assessed. Peri-procedural and one-year major adverse cardiovascular events (MACE) were compared using cumulative incidence plots. The primary outcome was MACE outcomes at 1-year, which was defined as a composite of all-cause mortality, rehospitalization for myocardial infarction (MI), rehospitalization for stroke or urgent revascularization.

Results

ULM PCI patients in comparison to PLM PCI were older (71.5 vs 69.2; P < 0.001), more clinically complex and more likely to present with ACS. In the propensity matched cohort, radial access was used more often for ULM PCI (21% [273] vs. 14% [185], P < 0.001), and ULM PCI was more likely to involve the LM bifurcation (22% vs 14%; P = 0.003) and require mechanical circulatory support (10% [134] vs 1% [17]; P <0.001). One-year MACE occurred more frequently with ULM PCI compared to PLM PCI (22% [289] vs. 16% [215]; P = < 0.001) and all-cause mortality was also higher (16% [213] vs. 10% [125]; P = < 0.001). In the matched cohort there was a low incidence of rehospitalization for MI (4% [48] ULM vs. 4% [48] PLM; P = 1.000) or revascularization (7% [94] ULM vs. 6% [84] PLM; P = 0.485).

Conclusions

Veterans undergoing PLM PCI had better one-year outcomes than those undergoing ULM PCI, but in both groups there was a high rate of mortality and MACE at one-year despite a relatively low rate of MI or revascularization.

Trends and Outcomes in Patients With Coronary Artery Disease Undergoing TAVR: Insights From VA CART

Background

Obstructive coronary artery disease (CAD) is common in patients with severe symptomatic aortic stenosis. The management and impact of obstructive CAD in patients undergoing transcatheter aortic valve replacement (TAVR) have not been fully evaluated. We aimed to determine the patient characteristics and clinical outcomes among veterans undergoing TAVR with and without obstructive CAD and to determine temporal trends and association of pre-TAVR percutaneous coronary intervention (PCI) with clinical outcomes.

Methods

We identified all patients who underwent TAVR from 2012 to 2021 in the VA Health Care System. The sample population was divided into patients with and without obstructive CAD and further stratified by coronary intervention status 1 year prior to TAVR. The primary outcome was 1-year all-cause mortality, and the secondary outcome was major bleeding.

Results

During the study period, 759 patients underwent TAVR, and 282 (37%) had obstructive CAD. Obstructive CAD was associated with higher 1-year mortality (15.6% vs 7.1%; P < .01) after TAVR. The rate of PCI prior to TAVR increased from 2012 until 2016, after which it steadily declined such that 144 patients (51%) underwent PCI pre-TAVR during the entire study period. There was no difference in 1-year mortality (16.0% vs 15.2%; P = .89) or bleeding (16.7% vs 12.3%; P = .33) between patients who underwent or did not undergo pre-TAVR PCI.

Conclusions

Among veterans undergoing TAVR, the presence of obstructive CAD is associated with higher mortality though pre-TAVR coronary intervention is not associated with improved outcomes. Further studies could identify a subset of patients who may benefit from coronary revascularization prior to TAVR.

Projected Outcomes of Optimized Statin and Ezetimibe Therapy in US Military Veterans with Coronary Artery Disease

Importance

Many patients with coronary artery disease (CAD) do not achieve the guideline-directed goals for low-density lipoprotein cholesterol (LDL-C) levels.

Objective

To estimate reductions in the rates of adverse events associated with CAD in a large US military veteran population that may be achieved through use of optimized statin therapy alone or with ezetimibe compared with the prevailing lipid-lowering therapy (LLT).

Design, Setting, and Participants

In this observational cohort study, US military veterans with CAD were identified by coronary angiography between June 2015 and September 2020 across 82 US Department of Veterans Affairs health care facilities.

Exposures

The exposures were observed LLT, LLT with an optimized statin regimen, and LLT with optimized statin and ezetimibe.

Main Outcomes and Measures

Observed rates of death, myocardial infarction, stroke, and coronary revascularization, and potential reductions in those outcomes with optimized LLT based on expected further reductions in LDL-C levels and application of formulas from The Cholesterol Treatment Trialists' Collaboration.

Results

The analysis cohort comprised 111 954 veterans (mean [SD] age, 68.4 [8.8] years; 109 390 men [97.7%]; 91 589 White patients [81.8%]; 17 592 Black patients [15.7%]). The median (IQR) observation period for this study was 3.4 (2.1-4.0) years. At the time of index angiography, 66 877 patients (59.7%) were treated with statin therapy, and 623 patients (0.6%) were treated with ezetimibe. At 6 months, the number of patients with statin prescriptions increased to 74 400 (68.7%), but the number of patients with high-intensity statin prescriptions was only 57 297 (52.9%). At 6 months, ezetimibe use remained low (n = 1168 [1.1%]), and LDL-C levels were 70 mg/dL or more in 56 405 patients (52.1%). At 4 years, observed incidences of death, myocardial infarction, stroke, and coronary revascularization were 21.6% (95% CI, 21.3%-21.8%), 5.0% (95% CI, 4.9%-5.2%), 2.2% (95% CI, 2.1%-2.3%), and 15.4% (95% CI, 15.2%-15.7%), respectively. With optimized statin treatment, projected absolute reductions in these incidences were 1.3% (95% CI, 0.9%-1.7%), 0.8% (95% CI, 0.7%-1.0%), 0.2% (95% CI, 0.1%-0.3%), and 2.3% (95% CI, 2.0%-2.7%), respectively. With optimized statin and ezetimibe treatment, projected absolute reductions were 1.8% (95% CI, 1.2%-2.4%), 1.1% (95% CI, 0.9%-1.3%), 0.3% (95% CI, 0.2%-0.4%), and 3.1% (95% CI, 2.6%-3.6%), respectively.

Conclusions and Relevance

In this cohort study of veterans with CAD, suboptimal LLT was prevalent in the clinical setting. Optimization of statin therapy was projected to produce clinically relevant reductions in the risks of death and cardiovascular events. Despite a lesser lipid-lowering efficacy of ezetimibe, its widespread use on a population level in conjunction with optimized statin therapy may be associated with further meaningful reductions in cardiovascular risk.

Association between Surgical Technical Skills and Clinical Outcomes: A Systematic Literature Review and Meta-Analysis

Background

A systematic literature review and meta-analysis was conducted to assess the association between intraoperative surgical skill and clinical outcomes.

Methods

Peer-reviewed, original research articles published through August 31, 2021 were identified from PubMed and Embase. From the 1,513 potential articles, seven met eligibility requirements, reporting on 151 surgeons and 17,932 procedures. All included retrospective assessment of operative videos. Associations between surgical skill and outcomes were assessed by pooling odds ratios (OR) using random-effects models with the inverse variance method. Eligible studies included pancreaticoduodenectomy, gastric bypass, laparoscopic gastrectomy, prostatectomy, colorectal, and hemicolectomy procedures.

Results

Meta-analytic pooling identified significant associations between the highest vs. lowest quartile of surgical skill and reoperation (OR: 0.44; 95% confidence interval [CI]: 0.23, 0.83), hemorrhage (OR: 0.66; 95% CI, 0.65, 0.68), obstruction (OR: 0.33; 95% CI, 0.30, 0.35), and any medical complication (OR: 0.23, 95% CI, 0.19, 0.27). Nonsignificant inverse associations were noted between skill and readmission, emergency department visit, mortality, leak, infection, venous thromboembolism, and cardiac and pulmonary complications.

Conclusions

Overall, surgeon technical skill appears to predict clinical outcomes. However, there are surprisingly few articles that evaluate this association. The authors recommend a thoughtful approach for the development of a comprehensive surgical quality infrastructure that could significantly reduce the challenges identified by this study.

Addressing unmeasured confounding bias with a prior knowledge guided approach: coronary artery bypass grafting (CABG) versus percutaneous coronary intervention (PCI) in patients with stable ischemic heart disease

Unmeasured confounding undermines the validity of observational studies. Although randomized clinical trials (RCTs) are considered the "gold standard" of study types, we often observe divergent findings between RCTs and empirical settings. We present the "L-table", a simulation-based, prior knowledge (e.g., RCTs) guided approach that estimates the true effect adjusting for the potential influence of unmeasured confounders when using observational data. Using electronic health record data from Kaiser Permanente Southern California, we compare the effectiveness of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) on endpoints at 1, 3, 5, and 10 years for patients with stable ischemic heart disease. We applied the L-table approach to the propensity score adjusted cohort to derive the omitted-confounder-adjusted estimated effects. After the L-table adjustment, CABG patients are 57.6% less likely to encounter major adverse cardiac and cerebrovascular event (MACCE) at 1 year (OR [95% CI] 0.424 [0.396, 0.517]), 56.4% less likely at 3 years (OR [95% CI] 0.436 [0.369, 0.527]), and 48.9% less likely at 5 years (OR [95% CI] 0.511 [0.451, 0.538]). CABG patients are also 49.5% less likely to die by the end of 10 years than PCI patients (OR [95% CI] 0.505 [0.446, 0.582]). We found the estimated true effects all shifted towards CABG as a more effective procedure that led to better health outcomes compared to PCI. Unlike existing sensitivity tools, the L-table approach explicitly lays out probable values and can therefore better support clinical decision-making. We recommend using L-table as a supplement to available techniques of sensitivity analysis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10742-022-00282-y.

Association of Residual Ischemic Disease With Clinical Outcomes After Percutaneous Coronary Intervention

BACKGROUND

Anatomical scoring systems have been used to assess completeness of revascularization but are challenging to apply to large real-world datasets.

OBJECTIVES

The aim of this study was to assess the prevalence of complete revascularization and its association with longitudinal clinical outcomes in the U.S. Department of Veterans Affairs (VA) health care system using an automatically computed anatomic complexity score.

METHODS

Patients undergoing percutaneous coronary intervention (PCI) between October 1, 2007, and September 30, 2020, were identified, and the burden of prerevascularization and postrevascularization ischemic disease was quantified using the VA SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) score. The association between residual VA SYNTAX score and long-term major adverse cardiovascular events (MACE; death, myocardial infarction, repeat revascularization, and stroke) was assessed.

RESULTS

A total of 57,476 veterans underwent PCI during the study period. After adjustment, the highest tertile of residual VA SYNTAX score was associated with increased hazard of MACE (HR: 2.06; 95% CI: 1.98-2.15) and death (HR: 1.50; 95% CI: 1.41-1.59) at 3 years compared to complete revascularization (residual VA SYNTAX score = 0). Hazard of 1- and 3-year MACE increased as a function of residual disease, regardless of baseline disease severity or initial presentation with acute or chronic coronary syndrome.

CONCLUSIONS

Residual ischemic disease was strongly associated with long-term clinical outcomes in a contemporary national cohort of PCI patients. Automatically computed anatomic complexity scores can be used to assess the longitudinal risk for residual ischemic disease after PCI and may be implemented to improve interventional quality.

Dip-coating electromechanically active polymer actuators with SIBS from midblock-selective solvents to achieve full encapsulation for biomedical applications

Soft and compliant ionic electromechanically active polymer actuators (IEAPs) are a promising class of smart materials for biomedical and soft robotics applications. These materials change their shape in response to external stimuli like the electrical signal. This shape-change results solely from the ion flux inside the composite and hence the material can be miniaturized below the centimeter and millimeter levels-something that still poses a challenge for many other conventional actuation mechanisms in soft robotics (e.g., pneumatic, hydraulic, or tendon-based systems). However, the components used to prepare IEAPs are typically not safe for the biological environment, nor is the environment safe for the actuator. Safety concerns and unreliable operation in foreign liquid environments have been some of the main obstacles for the widespread adoption of IEAPs in many areas, e.g., in biomedical applications. Here we show a novel approach to fully encapsulate IEAP actuators with the biocompatible block copolymer SIBS (poly(styrene-block-isobutylene-block-styrene)) dissolved in block-selective solvents. Reduction in the bending amplitude due to the added passive layers, a common negative side-effect of encapsulating IEAPs, was not observed in this work. In conclusion, the encapsulated actuator is steered through a tortuous vasculature mock-up filled with a viscous buffer solution mimicking biological fluids.

Impact of the Dual Antiplatelet Therapy Score on Clinical Outcomes in Acute Coronary Syndrome Patients Receiving P2Y12 Inhibitor Monotherapy

Background

Dual antiplatelet therapy (DAPT) score is used to stratify ischemic and bleeding risk for antiplatelet therapy after percutaneous coronary intervention (PCI). This study assessed the association between the DAPT score and clinical outcomes in acute coronary syndrome (ACS) patients who were treated with P2Y12 inhibitor monotherapy.

Methods

A total of 498 ACS patients, with early aspirin discontinuation for various reasons and who received P2Y12 inhibitor monotherapy after PCI, were enrolled during the period from January 1, 2014 to December 31, 2018. The efficacy and safety between those with low (<2) and high (≥2) DAPT scores were compared during a 12-month follow-up after PCI. Inverse probability of treatment weighting was used to balance the covariates between the two groups. The primary endpoint was a composite outcome of all-cause mortality, recurrent ACS or unplanned revascularization, and stroke within 12 months. The safety endpoint was major bleeding, defined as Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding.

Results

The primary composite endpoint occurred in 11.56 and 14.38% of the low and high DAPT score groups, respectively. Although there was no significant difference in the primary composite endpoint between the two groups in the multivariate Cox proportional hazards models, the risk of recurrent ACS or unplanned revascularization was significantly higher in the high DAPT score group (adjusted hazard ratio [HR]: 1.900, 95% confidence interval [CI]: 1.095-3.295). The safety outcome for BARC 3 or 5 bleeding was similar between the two groups.

Conclusions

Our results indicate that ACS patients receiving P2Y12 monotherapy with high DAPT score had an increased risk of recurrent ACS or unplanned revascularization.

Contemporary Clinical and Coronary Anatomic Risk Model for 30-Day Mortality After Percutaneous Coronary Intervention

BACKGROUND

Percutaneous coronary intervention (PCI) procedures are increasing in clinical and anatomic complexity, likely increasing the calculated risk of mortality. There is need for a real-time risk prediction tool that includes clinical and coronary anatomic information that is integrated into the electronic medical record system.

METHODS

We assessed 70 503 PCIs performed in 73 Veterans Affairs hospitals from 2008 to 2019. We used regression and machine-learning strategies to develop a prediction model for 30-day mortality following PCI. We assessed model performance with and without inclusion of the Veterans Affairs SYNTAX score (Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery), an assessment of anatomic complexity. Finally, the discriminatory ability of the Veterans Affairs model was compared with the CathPCI mortality model.

RESULTS

The overall 30-day morality rate was 1.7%. The final model included 14 variables. Presentation status (salvage, emergent, urgent), ST-segment-elevation myocardial infarction, cardiogenic shock, age, congestive heart failure, prior valve disease, chronic kidney disease, chronic lung disease, atrial fibrillation, elevated international normalized ratio, and the Veterans Affairs SYNTAX score were all associated with increased risk of death, while increasing body mass index, hemoglobin level, and prior coronary artery bypass graft surgery were associated with lower risk of death. C-index for the development cohort was 0.93 (95% CI, 0.92-0.94) and for the 2019 validation cohort and the site validation cohort was 0.87 (95% CI, 0.83-0.92) and 0.86 (95% CI, 0.83-0.89), respectively. The positive likelihood ratio of predicting a mortality event in the top decile was 2.87% more accurate than the CathPCI mortality model. Inclusion of anatomic information in the model resulted in significant improvement in model performance (likelihood ratio test P<0.01).

CONCLUSIONS

This contemporary risk model accurately predicts 30-day post-PCI mortality using a combination of clinical and anatomic variables. This can be immediately implemented into clinical practice to promote personalized informed consent discussions and appropriate preparation for high-risk PCI cases.

Clinical Characteristics and Outcomes Among Patients Undergoing High-Risk Percutaneous Coronary Interventions by Single or Multiple Operators: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

Background High-risk percutaneous coronary intervention (HR-PCI) is increasingly common among contemporary patients with coronary artery disease. Experts have advocated for a collaborative 2-operator approach to support intraprocedural decision-making for these complex interventions. The impact of a second operator on patient and procedural outcomes is unknown. Methods and Results Patients who underwent HR-PCI from 2015 to 2018 within the Veterans Affairs Healthcare System were identified. Propensity-matched cohorts were generated to compare the outcomes following HR-PCI performed by a single or multiple (≥2) operators. The primary end point was the 12-month rate of major adverse cardiovascular events. We identified 6672 patients who underwent HR-PCI during the study period; 6211 (93%) were treated by a single operator, and 461 (7%) were treated by multiple operators, with a nonsignificant trend toward increased multioperator procedures over time. A higher proportion of patients treated by multiple operators underwent left main (10% versus 7%, P=0.045) or chronic total occlusion intervention (11% versus 5%, P<0.001). Lead interventionalists participating in multioperator procedures practiced at centers with higher annual HR-PCI volumes (124±71.3 versus 111±69.2; standardized mean difference, 0.197; P<0.001) but otherwise performed a similar number of HR-PCI procedures per year (34.4±35.3 versus 34.7±30.7; standardized mean difference, 0.388; P=0.841) compared with their peers performing single-operator interventions. In a propensity-matched cohort, there was no significant difference in major adverse cardiovascular events (32% versus 30%, P=0.444) between patients who underwent single-operator versus multioperator HR-PCI. Adjusted analyses accounting for site-level variance showed no significant differences in outcomes. Conclusions Patients who underwent multioperator HR-PCI had similar outcomes compared with single-operator procedures. Further studies are needed to determine if the addition of a second operator offers clinical benefits to a subset of HR-PCI patients undergoing left main or chronic total occlusion intervention.

Recommendations for strengthening the role of embedded researchers to accelerate implementation in health systems: Findings from a state-of-the-art (SOTA) conference workgroup

BACKGROUND

Traditional research approaches do not promote timely implementation of evidence-based innovations (EBIs) to benefit patients. Embedding research within health systems can accelerate EBI implementation by blending rigorous methods with practical considerations in real-world settings. A state-of-the-art (SOTA) conference was convened in February 2019 with five workgroups that addressed five facets of embedded research and its potential to impact healthcare. This article reports on results from the workgroup focused on how embedded research programs can be implemented into heath systems for greatest impact.

METHODS

Based on a pre-conference survey, participants indicating interest in accelerating implementation were invited to participate in the SOTA workgroup. Workgroup participants (N = 26) developed recommendations using consensus-building methods. Ideas were grouped by thematic clusters and voted on to identify top recommendations. A summary was presented to the full SOTA membership. Following the conference, the workgroup facilitators (LJD, CDH, NR) summarized workgroup findings, member-checked with workgroup members, and were used to develop recommendations.

RESULTS

The workgroup developed 12 recommendations to optimize impact of embedded researchers within health systems. The group highlighted the tension between "ROI vs. R01" goals-where health systems focus on achieving return on their investments (ROI) while embedded researchers focus on obtaining research funding (R01). Recommendations are targeted to three key stakeholder groups: researchers, funders, and health systems. Consensus for an ideal foundation to support optimal embedded research is one that (1) maximizes learning; (2) aligns goals across all 3 stakeholders; and (3) implements EBIs in a consistent and timely fashion.

CONCLUSIONS

Four cases illustrate a variety of ways that embedded research can be structured and conducted within systems, by demonstrating key embedded research values to enable collaborations with academic affiliates to generate actionable knowledge and meaningfully accelerate implementation of EBIs to benefit patients.

IMPLICATIONS

Embedded research approaches have potential for transforming health systems and impacting patient health. Accelerating embedded research should be a focused priority for funding agencies to maximize a collective return on investment.

Heart Team/Guidelines Discordance Is Associated With Increased Mortality: Data From a National Survey of Revascularization in Patients With Complex Coronary Artery Disease

BACKGROUND

Practice guidelines emphasize the role of the SYNTAX score (SS; Synergy Between PCI With TAXUS and Cardiac Surgery) in choosing between percutaneous coronary intervention and coronary artery bypass graft surgery in cases of complex coronary artery disease. There is paucity of data on the implementation of these recommendations in daily practice, and on the consequences of guideline discordant revascularization.

METHODS

This was a retrospective analysis of a prospective national survey of consecutive real world patients undergoing coronary revascularization for complex coronary artery disease according to decisions of local heart team at each center. SS was calculated at a dedicated CoreLab, and patients were classified as heart team/guidelines agreement/discordant.

RESULTS

Nine hundred seventy-nine patients (571 percutaneous coronary intervention and 408 coronary artery bypass graft) were included. Mean age was 65 years and the mean SS was 22. Heart team/guidelines discordance occurred in 170 (17.3%) patients. Independent predictors of heart team/guidelines discordance were age, admission to a center with no cardiac surgery service, SS, and previous percutaneous coronary intervention/myocardial infarction. A multivariate model based on these characteristics had a C statistic of 0.83. Thirty-day outcomes were similar in the agreement/discordance groups, however, heart team/guidelines discordance was associated with a significant increase in 3 year mortality (17.6% versus 8.4%; hazard ratio, 2.05; P=0.002) after multivariate adjustment.

CONCLUSIONS

Heart team/guidelines discordance is not infrequent in real world patients with complex coronary artery disease undergoing revascularization. This is more likely to occur in elderly patients, those with more complex coronary disease (as determined by the SS), and those treated at centers with no cardiac surgery service. These patients have a higher risk for mid-term mortality.

Clinical and Anatomic Complexity of Patients Undergoing Coronary Intervention With and Without On-Site Surgical Capabilities: Insights From the Veterans Affairs Clinical Assessment, Reporting and Tracking (CART) Program

BACKGROUND

Professional society consensus statements articulate the clinical and anatomic complexity of patients that may undergo percutaneous coronary intervention (PCI) without on-site cardiothoracic surgery, although compliance with these recommendations has not been assessed. We sought to evaluate the clinical and anatomic complexity of patients undergoing PCI with and without cardiothoracic surgery on-site.

METHODS

We identified all patients undergoing PCI in the Veterans Affairs health care system between October 2009 and September 2017. The clinical and anatomic complexity of patients treated at sites with or without cardiothoracic surgery was evaluated with a comparative interrupted time series, and mortality was ascertained in a propensity-matched cohort.

RESULTS

We identified 75 564 patients who underwent PCI, with the majority (53 708, 71%) treated at sites with cardiothoracic surgery. The overall clinical complexity was statistically greater for those treated at sites with cardiothoracic surgery (National Cardiovascular Data Registries CathPCI: 18.4) compared with those at sites without (17.8, P<0.001) throughout the study, with similar annual increases in complexity before (2% versus 3%; P=0.107) and after (3% versus 3%; P=0.704) January 2014. The anatomic complexity of patients treated was also statistically greater (Veterans Affairs SYNTAX: 11.0 versus 10.2; P<0.001) and increased at comparable rates (2% versus 1%, P=0.731) before 2014. After publication of the consensus statement, anatomic complexity declined at sites with cardiothoracic surgery (-2%) but increased at sites without on-site surgery (5%, P=0.025) such that it was similar at the end of the study (P=0.622). Referrals for emergent cardiothoracic surgery were rare regardless of treatment venue (61, 0.08%) and the hazard for mortality was similar (hazard ratio, 0.883 [95% CI, 0.662-1.176]) after propensity matching.

CONCLUSIONS

There are minor differences in complexity of patients undergoing coronary intervention at sites with and without cardiothoracic surgery. Clinical outcomes are similar regardless of treatment venue, suggesting an opportunity to improve access to complex interventional care without sacrificing quality.

Effect of Lesion Complexity and Clinical Risk Factors on the Efficacy and Safety of Dabigatran Dual Therapy Versus Warfarin Triple Therapy in Atrial Fibrillation After Percutaneous Coronary Intervention

Background:

The REDUAL PCI trial (Evaluation of Dual Therapy With Dabigatran vs Triple Therapy With Warfarin in Patients With AF That Undergo a PCI With Stenting) demonstrated that, in patients with atrial fibrillation following percutaneous coronary intervention, bleeding risk was lower with dabigatran plus clopidogrel or ticagrelor (dual therapy) than warfarin plus clopidogrel or ticagrelor and aspirin (triple therapy). Dual therapy was noninferior for risk of thromboembolic events. Whether these results apply equally to patients at higher risk of ischemic events due to lesion complexity or clinical risk factors is unclear.

Methods:

The primary end point was time to first major or clinically relevant nonmajor bleeding event. The composite efficacy end point was death, thromboembolic event, or unplanned revascularization. Our prespecified subgroup analysis categorized patients by presence of procedural complexity and/or clinical complexity factors at baseline. A modified dual antiplatelet therapy score categorized patients according to degree of clinical risk.

Results:

Of 2725 patients, 43.1% had clinical complexity factors alone, 9.9% procedural factors alone, 10.0% both, and 37.0% neither. Risk of the primary bleeding end point was lower in both dabigatran dual therapy groups than warfarin triple therapy groups, regardless of procedural and/or clinical lesion complexity (interaction P values: 0.90 and 0.37, respectively). Importantly, a similar risk of the efficacy end point was observed between dabigatran dual and warfarin triple therapy, regardless of the presence of clinical or procedural complexity factors (interaction P values: 0.67 and 0.54, dabigatran 110 and 150 mg dual therapy, respectively). Similar benefit was seen for each dose of dabigatran dual therapy for bleeding events regardless of dual antiplatelet therapy score (interaction P values: 0.53 and 0.54, respectively), with similar risk of thromboembolic events (interaction P values: 0.20 and 0.08, respectively).

Conclusions:

In patients with atrial fibrillation undergoing percutaneous coronary intervention, dabigatran 110 and 150 mg dual therapy reduced bleeding risk compared with warfarin triple therapy, with a similar risk of thromboembolic outcomes, irrespective of procedural and/or clinical complexity and modified dual antiplatelet therapy score.

Registration:

URL: https://clinicaltrials.gov/ ; Unique identifier: NCT02164864.

Mitochondrial 8-hydroxy-2'-deoxyguanosine and coronary artery disease in patients with type 2 diabetes mellitus

Background

Little is known about whether mitochondria 8-hydroxy-2′-deoxyguanosine (8-OHdG), a biomarker of mitochondrial DNA (mtDNA) oxidative damage, contributes to the development of coronary artery disease (CAD) in diabetic patients. Here, we explored the associations of mtDNA 8-OHdG in leukocytes with obstructive CAD, coronary stenosis severity, cardiovascular biomarkers, and 1-year adverse outcomes after coronary revascularization in patients with type 2 diabetes mellitus (T2DM).

Methods

In a total of 1920 consecutive patients with T2DM who underwent coronary angiography due to symptoms of angina or angina equivalents, the presence of obstructive CAD, the number of diseased vessels with ≥ 50% stenosis, and modified Gensini score were cross-sectionally evaluated; the level of mtDNA 8-OHdG was quantified by quantitative PCR. Then, 701 of 1920 diabetic patients who further received coronary revascularization completed 1-year prospective follow-up to document major adverse cardiovascular and cerebral events (MACCEs). In vitro experiments were also performed to observe the effects of mtDNA oxidative damage in high glucose-cultured human umbilical vein endothelial cells (HUVECs).

Results

Cross-sectionally, greater mtDNA 8-OHdG was associated with increased odds of obstructive CAD (odds ratio [OR] 1.38, 95% CI confidence interval 1.24–1.52), higher degree of coronary stenosis (number of diseased vessels: OR 1.29, 95% CI 1.19–1.41; modified Gensini scores: OR 1.28, 95% CI 1.18–1.39), and higher levels of C-reactive protein (β 0.18, 95% CI 0.06–0.31) after adjusting for confounders. Sensitivity analyses using propensity score matching yielded similar results. Stratification by smoking status showed that the association between mtDNA 8-OHdG and obstructive CAD was most evident in current smokers (P_interation < 0.01). Prospectively, the adjusted hazards ratio per 1-SD increase in mtDNA 8-OHdG was 1.59 (95% CI 1.33–1.90) for predicting 1-year MACCEs after revascularization. In HUVECs, exposure to antimycin A, an inducer for mtDNA oxidative damage, led to adverse alterations in markers of mitochondrial and endothelia function.

Conclusion

Greater mtDNA 8-OHdG in leukocytes may serve as an independent risk factor for CAD in patients with T2DM.

Temporal Trends and Site Variation in High-Risk Coronary Intervention and the Use of Mechanical Circulatory Support: Insights From the Veterans Affairs Clinical Assessment Reporting and Tracking (CART) Program

Background Patients undergoing percutaneous coronary intervention (PCI) are older with greater medical comorbidities and anatomical complexity than ever before, resulting in an increased frequency of nonemergent high-risk PCI (HR-PCI). We thus sought to evaluate the temporal trends in performance of HR-PCI and utilization of mechanical circulatory support in the largest integrated healthcare system in the United States. Methods and Results A cohort of high-risk adult patients that underwent nonemergent PCI in the Veterans Affairs Healthcare System between January 2008 and June 2018 were identified by objective clinical, hemodynamic, and anatomic criteria. Temporal trends in the performance of HR-PCI, utilization of mechanical circulatory support, and site-level variation were assessed. Of 111 548 patients assessed during the study period, 554 met 3 high-risk criteria whereas 4414 met at least 2 criteria for HR-PCI. There was a significant linear increase in the proportion of interventions that met 3 (P<0.001) or at least 2 (P<0.001) high-risk criteria over time, with rates approaching 1.9% and 11.2% in the last full calendar year analyzed. A minority of patients who met all high-risk criteria received PCI with mechanical support (15.7%) without a significant increase over time (P=0.193). However, there was significant site-level variation in the probability of performing HR-PCI (4.0-fold higher likelihood) and utilizing mechanical circulatory support (1.9-fold higher likelihood) between high and low utilization sites. Conclusions The proportion of cases categorized as HR-PCI has increased over time, with significant site-level variation in performance. The majority of HR-PCI cases did not utilize mechanical support, highlighting a discrepancy between current recommendations and clinical practice in an integrated healthcare system.

Same-day discharge among patients undergoing elective PCI: Insights from the VA CART Program

BACKGROUND

Available data suggest that same-day discharge (SDD) after elective percutaneous coronary intervention (PCI) is safe in select patients. Yet, little is known about contemporary adoption rates, safety, and costs in a universal health care system like the Veterans Affairs Health System.

METHODS

Using data from the Veterans Affairs Clinical Assessment Reporting and Tracking Program linked with Health Economics Resource Center data, patients undergoing elective PCI for stable angina between October 1, 2007 and Sepetember 30, 2016, were stratified by SDD versus overnight stay. We examined trends of SDD, and using 2:1 propensity matching, we assessed 30-day rates of readmission, mortality, and total costs at 30 days.

RESULTS

Of 21,261 PCIs from 67 sites, 728 were SDDs (3.9% of overall cohort). The rate of SDD increased from 1.6% in 2008 to 9.7% in 2016 (P < .001). SDD patients had lower rates of atrial fibrillation, peripheral arterial disease, and prior coronary artery bypass grafting and were treated at higher-volume centers. Thirty-day readmission and mortality did not differ significantly between the groups (readmission: 6.7% SDD vs 5.6% for overnight stay, P = .24; mortality: 0% vs. 0.07%, P = .99). The mean (SD) 30-day cost accrued by patients undergoing SDD was $23,656 ($15,480) versus $25,878 ($17,480) for an overnight stay. The accumulated median cost savings for SDD was $1503 (95% CI $738-$2,250).

CONCLUSIONS

Veterans Affairs Health System has increasingly adopted SDD for elective PCI procedures, and this is associated with cost savings without an increase in readmission or mortality. Greater adoption has the potential to reduce costs without increasing adverse outcomes.