Abnormal Wall Shear Stress Area is Correlated to Coronary Artery Bypass Graft Remodeling 1 Year After Surgery

Coronary artery bypass graft surgery is a common intervention for coronary artery disease; however, it suffers from graft failure, and the underlying mechanisms are not fully understood. To better understand the relation between graft hemodynamics and surgical outcomes, we performed computational fluid dynamics simulations with deformable vessel walls in 10 study participants (24 bypass grafts) based on CT and 4D flow MRI one month after surgery to quantify lumen diameter, wall shear stress (WSS), and related hemodynamic measures. A second CT acquisition was performed one year after surgery to quantify lumen remodeling. Compared to venous grafts, left internal mammary artery grafts experienced lower abnormal WSS (< 1 Pa) area one month after surgery (13.8 vs. 70.1%, p = 0.001) and less inward lumen remodeling one year after surgery (- 2.4% vs. - 16.1%, p = 0.027). Abnormal WSS area one month post surgery correlated with percent change in graft lumen diameter one year post surgery (p = 0.030). This study shows for the first time prospectively a correlation between abnormal WSS area one month post surgery and graft lumen remodeling 1 year post surgery, suggesting that shear-related mechanisms may play a role in post-operative graft remodeling and might help explain differences in failure rates between arterial and venous grafts.

Qualitative and Quantitative Stress Perfusion Cardiac Magnetic Resonance in Clinical Practice: A Comprehensive Review

Stress cardiovascular magnetic resonance (CMR) imaging is a well-validated non-invasive stress test to diagnose significant coronary artery disease (CAD), with higher diagnostic accuracy than other common functional imaging modalities. One-stop assessment of myocardial ischemia, cardiac function, and myocardial viability qualitatively and quantitatively has been proven to be a cost-effective method in clinical practice for CAD evaluation. Beyond diagnosis, stress CMR also provides prognostic information and guides coronary revascularisation. In addition to CAD, there is a large body of literature demonstrating CMR's diagnostic performance and prognostic value in other common cardiovascular diseases (CVDs), especially coronary microvascular dysfunction (CMD). This review focuses on the clinical applications of stress CMR, including stress CMR scanning methods, practical interpretation of stress CMR images, and clinical utility of stress CMR in a setting of CVDs with possible myocardial ischemia.

Empagliflozin and Left Ventricular Remodeling in People Without Diabetes: Primary Results of the EMPA-HEART 2 CardioLink-7 Randomized Clinical Trial

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors have been demonstrated to promote reverse cardiac remodeling in people with diabetes or heart failure. Although it has been theorized that sodium-glucose cotransporter 2 inhibitors might afford similar benefits in people without diabetes or prevalent heart failure, this has not been evaluated. We sought to determine whether sodium-glucose cotransporter 2 inhibition with empagliflozin leads to a decrease in left ventricular (LV) mass in people without type 2 diabetes or significant heart failure.

METHODS

Between April 2021 and January 2022, 169 individuals, 40 to 80 years of age, without diabetes but with risk factors for adverse cardiac remodeling were randomly assigned to empagliflozin (10 mg/d; n=85) or placebo (n=84) for 6 months. The primary outcome was the 6-month change in LV mass indexed (LVMi) to baseline body surface area as measured by cardiac magnetic resonance imaging. Other measures included 6-month changes in LV end-diastolic and LV end-systolic volumes indexed to baseline body surface area and LV ejection fraction.

RESULTS

Among the 169 participants (141 men [83%]; mean age, 59.3±10.5 years), baseline LVMi was 63.2±17.9 g/m² and 63.8±14.0 g/m² for the empagliflozin- and placebo-assigned groups, respectively. The difference (95% CI) in LVMi at 6 months in the empagliflozin group versus placebo group adjusted for baseline LVMi was -0.30 g/m² (-2.1 to 1.5 g/m²; P=0.74). Median baseline (interquartile range) NT-proBNP (N-terminal-pro B-type natriuretic peptide) was 51 pg/mL (20-105 pg/mL) and 55 pg/mL (21-132 pg/mL) for the empagliflozin- and placebo-assigned groups, respectively. The 6-month treatment effect of empagliflozin versus placebo (95% CI) on blood pressure and NT-proBNP (adjusted for baseline values) were -1.3 mm Hg (-5.2 to 2.6 mm Hg; P=0.52), 0.69 mm Hg (-1.9 to 3.3 mm Hg; P=0.60), and -6.1 pg/mL (-37.0 to 24.8 pg/mL; P=0.70) for systolic blood pressure, diastolic blood pressure, and NT-proBNP, respectively. No clinically meaningful between-group differences in LV volumes (diastolic and systolic indexed to baseline body surface area) or ejection fraction were observed. No difference in adverse events was noted between the groups.

CONCLUSIONS

Among people with neither diabetes nor significant heart failure but with risk factors for adverse cardiac remodeling, sodium-glucose cotransporter 2 inhibition with empagliflozin did not result in a meaningful reduction in LVMi after 6 months.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04461041.

Relationship Between Left Ventricular Strain Assessment by Cardiac Magnetic Resonance Imaging and Response to Cardiac Resynchronization Therapy

Although cardiac resynchronization therapy (CRT) is an established treatment for heart failure with reduced ejection fraction, 30 to 50% patients are non-responders. In this retrospective single-centre study, 19 patients underwent cardiac MRI pre-CRT, and global left ventricular (LV) strain and late gadolinium enhancement (LGE) were measured by a blinded reader. LV reverse remodeling was independently assessed using transthoracic echocardiogram before and after CRT implant. Both LV strain and extent of LGE correlated significantly with measures of reverse LV remodeling (reduction in LV volume and improvement in LV ejection fraction). These findings suggest that CMR derived strain analysis and scar evaluation may be useful preimplant predictors of response to CRT. Larger prospective multi-center studies are needed to confirm these findings and to further evaluate the role of CMR strain imaging in guiding CRT treatment decisions.

Objective risk assessment vs standard care for acute coronary syndromes-The Australian GRACE Risk tool Implementation Study (AGRIS): a process evaluation

Background

Structured risk-stratification to guide clinician assessment and engagement with evidence-based therapies may reduce care variance and improve patient outcomes for Acute Coronary Syndrome (ACS). The Australian Grace Risk score Intervention Study (AGRIS) explored the impact of the GRACE Risk Tool for stratification of ischaemic and bleeding risk in ACS. While hospitals in the active arm had a higher overall rate of invasive ACS management, there was neutral impact on important secondary prevention prescriptions/referrals, hospital performance measures, myocardial infarction and 12-month mortality leading to early trial cessation. Given the Grace Risk Tool is under investigation internationally, this process evaluation study provides important insights into the possible contribution of implementation fidelity on the AGRIS study findings.

Methods

Using maximum variation sampling, five hospitals were selected from the 12 centres enrolled in the active arm of AGRIS. From these facilities, 16 local implementation stakeholders (Cardiology advanced practice nurses, junior and senior doctors, study coordinators) consented to a semi-structured interview guided by the Theoretical Domains Framework. Directed Content Analysis of qualitative data was structured using the Capability/Opportunity/Motivation-Behaviour (COM-B) model.

Results

Physical capability was enhanced by tool usability. While local stakeholders supported educating frontline clinicians, non-cardiology clinicians struggled with specialist terminology. Physical opportunity was enhanced by the paper-based format but was hampered when busy clinicians viewed risk-stratification as one more thing to do, or when form visibility was neglected. Social opportunity was supported by a culture of research/evidence yet challenged by clinical workflow and rotating medical officers. Automatic motivation was strengthened by positive reinforcement. Reflective motivation revealed the GRACE Risk Tool as supporting but potentially overriding clinical judgment. Divergent professional roles and identity were a major barrier to integration of risk-stratification into routine Emergency Department practice. The cumulative result revealed poor form completion behaviors and a failure to embed risk-stratification into routine patient assessment, communication, documentation, and clinical practice behaviors.

Conclusions

Numerous factors negatively influenced AGRIS implementation fidelity. Given the prominence of risk assessment recommendations in United States, European and Australian guidelines, strategies that strengthen collaboration with Emergency Departments and integrate automated processes for risk-stratification may improve future translation internationally.

Assessments of right ventricular strain using cardiac magnetic resonance imaging following kidney transplantation

Although kidney transplantation (KT) has been shown to ameliorate adverse left ventricular (LV) remodelling associated with end stage kidney disease, its effects on the right ventricle have not been well studied. Recently, strain imaging has been shown to be a sensitive measure of early subclinical myocardial dysfunction. Using cardiac magnetic resonance imaging (MRI), we examined the effects of KT on right ventricular (RV) strain parameters. In a cohort of 81 patients (39 patients underwent KT and 42 patients remained on dialysis as control group), cardiac MRI studies were obtained at baseline and at 1 year follow-up. There were no significant differences in RV strain values between the groups at baseline. After 1 year, RV strain values did not significantly change in patients who received KT, and changes in RV strain over 1 year were not significantly different between the KT and the dialysis groups. Given the previously demonstrated improvement in LV strain post-KT, the current study suggests that RV and LV remodelling post-KT may have different mechanisms. Further studies elucidating the effects of KT on RV remodelling are needed.

The Increase in Paraoxonase 1 Is Associated With Decrease in Left Ventricular Volume in Kidney Transplant Recipients

Background: Patients on dialysis have impaired cardiac function, in part due to increased fluid volume and ventricular stress. Restored kidney function through transplantation reduces left ventricular volume in both systole and diastole. We previously reported that the decrease in NT-proB-type natriuretic peptide (NT-proBNP) was associated with a decrease in adiponectin. Paraoxonase 1 (PON1) has been inversely associated with cardiovascular outcomes. We now report the association of changes in PON1 with changes in left ventricular volume and left ventricular mass after kidney transplantation.

Design: Patients on dialysis were assessed at baseline and 12 months after kidney transplantation (n = 38). A comparison group of patients on dialysis who were not expected to receive a transplant in the next 24 months were studied (n = 43) to determine if the change of PON1 with kidney transplantation achieved a significance greater than that due to biologic variation. Left ventricular volume and mass were determined by cardiac magnetic resonance imaging. PON1 was measured by arylesterase activity and by mass.

Results: PON1 mass and activity were not different between the groups at baseline. Both PON1 mass and activity were increased post-kidney transplantation (p < 0.0001 for change). The change in PON1 mass (p = 0.0062) and PON1 arylesterase activity (p = 0.0254) were inversely correlated with the change in NT-proBNP for patients receiving a kidney transplant. However, only the change in the PON1 mass, and not the change in PON1 arylesterase, was inversely correlated with the change in left ventricular volume (ml/m2.7) (p = 0.0146 and 0.0114 for diastolic and systolic, respectively) and with the change in hemoglobin (p = 0.0042).

Conclusion: Both PON1 mass and arylesterase activity are increased by kidney transplantation. The increase in PON1 mass is consistent with a novel relationship to the increase in hemoglobin and decrease in left ventricular volume and NT-proBNP seen when kidney function is restored.

Antithrombotic Therapy After Percutaneous Coronary Intervention in Patients With Atrial Fibrillation: Findings From the CONNECT AF+PCI Study

Background

In patients with atrial fibrillation (AF) undergoing percutaneous coronary intervention (PCI), selecting an antithrombotic regimen requires balancing risks of ischemic cardiac events, stroke, and bleeding.

Methods

We studied 467 patients with AF undergoing PCI in the time period from December 2015 to July 2018 identified via a chart audit by 47 Canadian cardiologists in the CONNECT AF+PCI (the Coordinated National Network to Engage Interventional Cardiologists in the Antithrombotic Treatment of Patients With Atrial Fibrillation Undergoing Percutaneous Coronary Intervention) study, to determine patterns of initial antithrombotic therapy selection.

Results

The median (25th, 75th percentile) CHADS₂ score was 2 (1, 3), and PCI was performed in the setting of acute coronary syndrome in 62.1%. Triple antithrombotic therapy (TAT) was the initial treatment in 62.7%, dual-pathway therapy in 25.7%, and dual antiplatelet therapy in 11.6%, with a temporal increase in use of dual-pathway therapy during the course of the study; median intended TAT duration was 1 (1, 3) month. Compared with patients selected for TAT, patients selected for dual-pathway therapy were less likely to have prior myocardial infarction (35.8% vs 25.8%, P = 0.045) and prior PCI (33.8% vs 23.3%, P = 0.03), and they received shorter total length of stents (38 [23, 56] vs 30 [20, 46] mm, P = 0.03). Patients selected for dual-pathway therapy had a higher prevalence of prior stroke/transient ischemic attack (13.0% vs 23.3%, P = 0.01). There was no difference in prevalence of anemia (21.5% vs 25.8%, P = 0.30). Use of dual-pathway therapy was similar among patients with acute coronary syndrome and those with stable disease (24.1% vs 28.2%, P = 0.32).

Conclusions

Approximately one-quarter of AF patients undergoing PCI are treated with dual-pathway therapy in Canadian practice, with its use increasing during the studied period. Patients selected for dual-pathway therapy have less-complex coronary disease history and intervention.

Provision of a DAPT Score to Cardiologists and Extension of Dual Antiplatelet Therapy Beyond 1 Year After ACS: Randomized Substudy of the Prospective Canadian ACS Reflective II Study

Background

Extension of dual antiplatelet therapy (DAPT) beyond 1 year after acute coronary syndrome is associated with a reduction in ischemic events but also increased bleeding. The DAPT score identifies individuals likely to derive overall benefit or harm from DAPT extension. We sought to evaluate the impact of providing the DAPT score to treating physicians on the decision to extend DAPT beyond 1 year after non–ST-segment elevation myocardial infarction.

Methods

Moderate to high-risk non–ST-segment elevation myocardial infarction patients were enrolled from July 2016 to May 2018 in 13 Canadian hospitals by 52 cardiologists. Participating cardiologists were randomly assigned 1:1 to receive their individual patients’ DAPT scores before the 1-year follow-up visit vs not receiving their patients’ DAPT scores. Rates of DAPT extension were compared among the randomized groups.

Results

At 1 year, 370 of the 585 (63.2%) patients discharged on DAPT were receiving DAPT. Among patients on DAPT at 1 year, the median (25th, 75th percentile) DAPT score was 2 (1,3). DAPT was extended beyond 1 year in 36.2% randomly assigned to provision of DAPT score vs 35.7% in the control group (P = 0.93). In the subgroup of patients with DAPT score ≥ 2, DAPT extension was 49.5% in the DAPT score provision arm vs 40.4% in the control arm (P = 0.22); among patients with DAPT score < 2, DAPT termination was 78.6% in the DAPT score provision arm vs 70.6% in the control arm (P = 0.26) (P value for interaction = 0.1).

Conclusions

In this exploratory randomized trial, provision of the DAPT score to treating physicians had no impact on the duration of DAPT treatment beyond 1 year.

Determinants of long-term dual antiplatelet therapy use in post myocardial infarction patients: Insights from the TIGRIS registry

BACKGROUND

Patterns of dual antiplatelet therapy (DAPT) use beyond 1 year post-myocardial infarction (MI) have not been well studied.

METHODS

TIGRIS (NCT01866904) was a prospective, multi-center (369 centers in 24 countries), observational study of patients 1 to 3 years post-MI. We sought to identify the prevalence and determinants of DAPT use ≥1 year post-MI in patients enrolled in TIGRIS. We used multivariable logistic regression to identify determinants of DAPT use at 396 days post-MI (365 days plus a 31day overrun period to account for intended DAPT discontinuation at 1 year). Patients treated with an oral anticoagulant were excluded.

RESULTS

Of 7708 patients (median age 67 years, women 25%, ST-elevation MI 50%), 39% and 16% were on DAPT at 396 days and 5 years post-MI, respectively. DAPT use at 396 days post-MI was more prevalent in patients <65 years of age, treated with percutaneous coronary intervention (versus coronary artery bypass grafting or medical therapy), and with multivessel disease or a history of angina. Additional clinical determinants of ischemic and/or bleeding events following MI (diabetes, second prior MI, hypertension, peripheral artery disease, heart failure, smoking, and renal insufficiency) were not independently associated with DAPT use at 396 days. There were geographic variations in the use of DAPT at 396 days (p<0.001), with the lowest use in Europe and the highest in Asia and Australia.

CONCLUSION

In a contemporary patient cohort, DAPT use beyond 1 year post MI was prevalent and associated with patient and index event characteristics. There were marked geographical variations in DAPT use beyond 1 year post MI.

Right Ventricular Mass 12 Years after Osteosarcoma: Multimodality Imaging with Pathologic Correlation

The authors report a 27-year-old woman with a remote left femoral osteosarcoma and amputation above the left knee who presented with a large right ventricular mass. Initial evaluation with thoracic CT was inconclusive regarding thrombus versus tumor, but metastatic osteosarcoma was suggested by findings at transthoracic echocardiography, cardiac CT, and cardiac MRI. The patient underwent tumor debulking, and osteosarcoma was confirmed with pathologic examination. She responded to chemotherapy, which resulted in reduction in size of the residual right ventricular tumor and of a few pulmonary metastases. Following induction chemotherapy, patient remains well undergoing maintenance therapy with an oral tyrosine kinase inhibitor. Keywords: CT, Echocardiography, MR Imaging, Intraoperative, Cardiac, Heart, Right Ventricle, Imaging Sequences, Metastases, Oncology Supplemental material is available for this article. © RSNA, 2021.

Comparison of Prasugrel and Ticagrelor for Patients with Acute Coronary Syndrome: A Systematic Review and Meta-analysis

INTRODUCTION

There has been inconsistent data on the direct comparison of prasugrel and ticagrelor. This meta-analysis was conducted to summarise the current available evidence.

METHODS

We performed a meta-analysis (PROSPERO-registered CRD42020166810) of randomized trials up to Feb 2020 that compared prasugrel and ticagrelor in acute coronary syndrome with respect to the composite endpoint of myocardial infarction (MI), stroke or cardiovascular death, and secondary endpoints including MI, stroke, cardiovascular death, major bleeding (Bleeding Academic Research Consortium (BARC) type 2 or above), stent thrombosis, all-cause death and other safety outcomes.

RESULTS

Of the 11 eligible RCTs with 6098 patients randomized to prasugrel (n=3050) or ticagrelor (n=3048), 180 and 207 had the composite endpoint events in the prasugrel arm and the ticagrelor arm respectively over a weighted mean follow up period of 11±2 months. Compared with prasugrel, the ticagrelor group had similar risk in the primary composite endpoint (Risk Ratio (RR)= 1.17; 95% CI=0.96-1.42; p=0.12, I2=0%). Compared to prasugrel, there was no significant difference associated with the use of ticagrelor groups with respect to stroke (RR=1.05; 95% CI=0.66-1.67; p=0.84, I2=0%); cardiovascular death (RR=1.01; 95% CI=0.75-1.36; p=0.95, I2=0%); BARC type 2 or above bleeding (RR=1.16; 95% CI =0.89-1.52; p=0.26, I2=0%); stent thrombosis (RR=1.58; 95% CI =0.90-2.76; p=0.11, I2=0%); all cause death (RR=1.10; 95% CI =0.86-1.43; p=0.45, I2=0%) except MI (RR=1.38; 95% CI=1.05-1.81; p=0.02, I2=0%) Conclusion: Compared with prasugrel, ticagrelor did not reduce the primary composite endpoint of MI, stroke and cardiovascular death at a weighted mean follow up of 11 months. There was no significant difference between the secondary outcomes except myocardial infarction.

Myocardial strain assessment using cardiovascular magnetic resonance imaging in recipients of implantable cardioverter defibrillators

BACKGROUND

Cardiovascular magnetic resonance (CMR) is increasingly used in the evaluation of patients who are potential candidates for implantable cardioverter-defibrillator (ICD) therapy to assess left ventricular (LV) ejection fraction (LVEF), myocardial fibrosis, and etiology of cardiomyopathy. It is unclear whether CMR-derived strain measurements are predictive of appropriate shocks and death among patients who receive an ICD. We evaluated the prognostic value of LV strain parameters on feature-tracking (FT) CMR in patients who underwent subsequent ICD implant for primary or secondary prevention of sudden cardiac death.

METHODS

Consecutive patients from 2 Canadian tertiary care hospitals who underwent ICD implant and had a pre-implant CMR scan were included. Using FT-CMR, a single, blinded, reader measured LV global longitudinal (GLS), circumferential (GCS), and radial (GRS) strain. Cox proportional hazards regression was performed to assess the associations between strain measurements and the primary composite endpoint of all-cause death or appropriate ICD shock that was independently ascertained.

RESULTS

Of 364 patients (mean 61 years, mean LVEF 32%), 64(17.6%) died and 118(32.4%) reached the primary endpoint over a median follow-up of 62 months. Univariate analyses showed significant associations between GLS, GCS, and GRS and appropriate ICD shocks or death (all p < 0.01). In multivariable Cox models incorporating LVEF, GLS remained an independent predictor of both the primary endpoint (HR 1.05 per 1% higher GLS, 95% CI 1.01-1.09, p = 0.010) and death alone (HR 1.06 per 1% higher GLS, 95% CI 1.02-1.11, p = 0.003). There was no significant interaction between GLS and indication for ICD implant, presence of ischemic heart disease or late gadolinium enhancement (all p > 0.30).

CONCLUSIONS

GLS by FT-CMR is an independent predictor of appropriate shocks or mortality in ICD patients, beyond conventional prognosticators including LVEF. Further study is needed to elucidate the role of LV strain analysis to refine risk stratification in routine assessment of ICD treatment benefit.

The Risk of Acute Kidney Injury with Oral Anticoagulants in Elderly Adults with Atrial Fibrillation

BACKGROUND AND OBJECTIVES

Anticoagulation with either a vitamin K antagonist or a direct oral anticoagulant may be associated with AKI. Our objective was to assess the risk of AKI among elderly individuals with atrial fibrillation newly prescribed a direct oral anticoagulant (dabigatran, rivaroxaban, or apixaban) versus warfarin.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our population-based cohort study included 20,683 outpatients in Ontario, Canada, ≥66 years with atrial fibrillation who were prescribed warfarin, dabigatran, rivaroxaban, or apixaban between 2009 and 2017. Inverse probability of treatment weighting on the basis of derived propensity scores for the treatment with each direct oral anticoagulant was used to balance baseline characteristics among patients receiving each of the three direct oral anticoagulants compared with warfarin. Cox proportional hazards regression was performed in the weighted population to compare the association between the prescribed anticoagulant and the outcomes of interest. The exposure was an outpatient prescription of warfarin or one of the direct oral anticoagulants. The primary outcome was a hospital encounter with AKI, defined using Kidney Disease Improving Global Outcomes thresholds. Prespecified subgroup analyses were conducted by eGFR category and by the percentage of international normalized ratio measurements in range, a validated marker of anticoagulation control.

RESULTS

Each direct oral anticoagulant was associated with a significantly lower risk of AKI compared with warfarin (weighted hazard ratio, 0.65; 95% confidence interval, 0.53 to 0.80 for dabigatran; weighted hazard ratio, 0.85; 95% confidence interval, 0.73 to 0.98 for rivaroxaban; and weighted hazard ratio, 0.81; 95% confidence interval, 0.72 to 0.93 for apixaban). In the subgroup analysis, the lower risk of AKI associated with each direct oral anticoagulant was consistent across each eGFR strata. The risk of AKI was significantly lower among users of each of the direct oral anticoagulants compared with warfarin users who had a percentage of international normalized ratio measurements ≤56%.

CONCLUSIONS

Direct oral anticoagulants were associated with a lower risk of AKI compared with warfarin.

Cardiovascular risk factor management in patients with diabetes: Does management differ with disease duration?

AIMS

Our objective was to examine risk factor modification targets and treatment in relation to duration of diabetes.

METHODS

The Diabetes Mellitus Status in Canada (DM-SCAN) study collected data on 5109 patients with type 2 diabetes mellitus (T2DM) in 2012 in primary care. We compared the prevalence of vascular complications, treatment targets, and interventions between patients with diagnosed diabetes duration ≤10 and > 10 years.

RESULTS

Physicians more frequently assigned HbA1c (glycated hemoglobin) targets of 7.1-8.5% (54-69 mmol/mol) to patients with longer duration of diabetes (n = 1647) (19.8% vs 9.5%, p < 0.001). Patients with longer duration of diabetes were less likely to achieve HbA1c targets of ≤7.0% (53 mmol/mol) (39% vs. 55%, p < 0.001), had similar likelihood of achieving blood pressure targets of ≤130/80 mmHg (38% vs. 36%, p = 0.26) and were more likely to achieve LDL-C targets of ≤2.0 mmol/L (≤77.3 mg/dL) (63% vs. 53%, p < 0.001) compared to patients with shorter duration of diabetes (n = 3462). Achievement of all three targets between both groups were similar (13% vs. 13%, p = 0.82). Overall, patients with longer duration of diabetes were more likely to be prescribed anti-hyperglycemic, anti-hypertensive, lipid-lowering medications and referred for diabetes education.

CONCLUSIONS

Only 13% of patients achieved glycemic, blood pressure, and LDL-C targets irrespective of duration of diabetes. Despite being managed with more medications, patients with longer duration of diabetes were less likely to achieve glycemic targets. More focus is needed on developing methods to bridge best care and real-world practice.

Development of Acute Myocardial Infarction Mortality and Readmission Models for Public Reporting on Hospital Performance in Canada

Background

Given changes in the care and outcomes of acute myocardial infarction (AMI) patients over the past several decades, we sought to develop prediction models that could be used to generate accurate risk-adjusted mortality and readmission outcomes for hospitals in current practice across Canada.

Methods

A Canadian national expert panel was convened to define appropriate AMI patients for reporting and develop prediction models. Preliminary candidate variable evaluation was conducted using Ontario patients hospitalized with a most responsible diagnosis of AMI from April 1, 2015 to March 31, 2018. National data from the Canadian Institute for Health Information was used to develop AMI prediction models. The main outcomes were 30-day all-cause in-hospital mortality and 30-day urgent all-cause readmission. Discrimination of these models (measured by c-statistics) was compared with that of existing Canadian Institute for Health Information models in the same study cohort.

Results

The AMI mortality model was assessed in 54,240 Ontario AMI patients and 153,523 AMI patients across Canada. We observed a 30-day in-hospital mortality rate of 6.3%, and a 30-day all-cause urgent readmission rate of 10.7% in Canada. The final Canadian AMI mortality model included 12 variables and had a c-statistic of 0.834. For readmission, the model had 13 variables and a c-statistic of 0.679. Discrimination of the new AMI models had higher c-statistics compared with existing models (c-statistic 0.814 for mortality; 0.673 for readmission).

Conclusions

In this national collaboration, we developed mortality and readmission models that are suitable for profiling performance of hospitals treating AMI patients in Canada.

Atrial structure and function in middle-aged, physically-active males and females: A cardiac magnetic resonance study

Recent studies have reported on an association between endurance sport, atrial enlargement and the development of lone atrial fibrillation in younger, male cohorts. The atrial morphology and function of middle‐aged, physically‐active males and females have not been well studied. We hypothesized that middle‐aged males would demonstrate larger left atrium (LA) and right atrium (RA) volumes compared to females, but atrial function would not differ. LA and RA volume and function were evaluated at rest in healthy adults, using a standardized 3.0Tesla cardiac magnetic resonance protocol. Physical activity, medical history, and maximal oxygen consumption (V˙O2peak) were also assessed. Physically‐active, middle‐aged men (n = 60; 54 ± 5 years old) and women (n = 30; 54 ± 5 years old) completed this study. Males had a higher body mass index, systolic blood pressure, and V˙O2peak than females (p < .05 for all), despite similar reported physical activity levels. Absolute and BSA and height‐indexed LA and RA maximum volumes were higher in males relative to females, despite no differences in ejection fractions (p < .05 for all). In multivariable regression, male sex p < .001) and V˙O2peak (p = .004) were predictors of LA volume (model R² = 0.252), whereas V˙O2peak (p < .001), male sex (p = .03), and RV EF (p < .05) were predictors of RA volume (model R² = 0.377). While middle‐aged males exhibited larger atrial volumes relative to females, larger, prospective studies are needed to explore the magnitude of physiologic atrial remodeling and functional adaptations in relation to phenotypic factors.

Right Ventricular Function at Cardiac MRI Predicts Cardiovascular Events in Patients with an Implantable Cardioverter-Defibrillator

Background Right ventricular ejection fraction (RVEF) is an independent predictor of death and adverse cardiovascular outcomes in patients with various cardiac conditions. Purpose To investigate whether RVEF, measured with cardiac MRI, is a predictor of appropriate shock or death in implantable cardioverter-defibrillator (ICD) recipients for primary and secondary prevention of sudden cardiac death. Materials and Methods This retrospective, multicenter, observational study included patients who underwent cardiac MRI before ICD implantation between January 2007 and May 2017. Right ventricular end-diastolic and end-systolic volumes and RVEF were measured with cardiac MRI. The primary end point was a composite of all-cause mortality or appropriate ICD shock. The secondary end point was all-cause mortality. The association between RVEF and primary and secondary outcomes was evaluated by using multivariable Cox regression analysis. Potential interactions were tested between primary prevention, ischemic cause, left ventricular ejection fraction (LVEF), and RVEF. Results Among 411 patients (mean age ± standard deviation, 60 years; 315 men) during a median follow-up of 63 months, 143 (35%) patients experienced an appropriate ICD shock or died. In univariable analysis, lower RVEF was associated with greater risks for appropriate ICD shock or death and for death alone (log-rank trend test, P = .003 and .005 respectively). In multivariable Cox regression analysis adjusting for age at ICD implantation, LVEF, ICD indication (primary vs secondary), ischemic heart disease, and late gadolinium enhancement, RVEF was an independent predictor of the primary outcome (hazard ratio [HR], 1.21 per 10% lower RVEF; 95% CI: 1.04, 1.41; P = .01) and all-cause mortality (HR, 1.25 per 10% lower RVEF; 95% CI: 1.01, 1.55; P = .04). No evidence of significant interactions was found between RVEF and primary or secondary prevention (HR, 1.11 ± 0.17 [standard deviation]; P = .49), ischemic heart disease (HR, 1.02 ± 0.15; P = .78), and LVEF (HR, 0.91 ± 0.8; P = .29). Conclusion Right ventricular ejection fraction measured with cardiac MRI was a predictor of appropriate implantable cardioverter-defibrillator shock or death. © RSNA, 2021 See also the editorial by Nazarian and Zghaib in this issue.