Antithrombotic therapies in Canadian atrial fibrillation patients with concomitant coronary artery disease: Insights from the CONNECT AF + PCI-II program.

BACKGROUND: Selecting the appropriate antithrombotic regimen for patients with atrial fibrillation (AF) who have undergone percutaneous coronary intervention (PCI) or have had medically managed acute coronary syndrome (ACS) remains complex. This multi-centre observational study evaluated patterns of antithrombotic therapies utilized among Canadian patients with AF post-PCI or ACS. METHODS AND RESULTS: By retrospective chart audit, 611 non-valvular AF patients [median (interquartile range) age 76 (69-83) years, CHADS2 score 2 (1-3)] who underwent PCI or had medically managed ACS between August 2018 and December 2020 were identified by 68 cardiologists across eight provinces in Canada. Overall, triple antithrombotic therapy [TAT: combined oral anticoagulation (OAC) and dual antiplatelet therapy (DAPT)] was the most common initial antithrombotic strategy, with use in 53.8 % of patients, followed by dual pathway therapy (32.7 % received OAC and a P2Y12 inhibitor, and 4.1 % received OAC and aspirin) and DAPT (9.3 %). Median duration of TAT was 30 (7, 30) days. Compared to the previous CONNECT AF + PCI-I program, there was an increased use of dual pathway therapy relative to TAT over time (P-value <.0001). DOACs (direct oral anticoagulants) represented 90.3 % of all OACs used overall, with apixaban being the most utilized (50.5 %). Proton pump inhibitors were used in 57.0 % of all patients, and 70.1 % of patients on ASA. Planned antithrombotic therapies at 1 year were: 76.2 % OAC monotherapy, 8.3 % OAC + ASA, 7.9 % OAC + P2Y12 inhibitor, 4.3 % DAPT, 1.3 % ASA alone, and <1 % triple therapy. CONCLUSION: In accordance with recent Canadian Cardiovascular Society guideline recommendations, we observed an increased use of dual pathway therapy relative to TAT over time in both AF patients post-PCI (elective and emergent) and in those with medically managed ACS. Additionally, DOACs have become the prevailing form of anticoagulation across all antithrombotic regimens. Our findings suggest that Canadian physicians are integrating evidence-based approaches to optimally manage the bleeding and thrombotic risks of AF patients post-PCI and/or ACS.

Effectiveness of medical therapy for treatment of idiopathic frequent premature ventricular complexes.

INTRODUCTION: The relative effectiveness of medical therapy compared with a conservative approach of monitoring in patients with idiopathic frequent premature ventricular complexes (PVCs) is uncertain. We evaluated the effectiveness of medical versus conservative therapy for frequent PVCs. METHODS: Patients with frequent PVCs (≥5%) were prospectively enrolled in this cohort study between 2016 and 2020. In patients with normal cardiac function and no structural heart disease, those receiving medical therapy were compared with controls without therapy. Patients were followed longitudinally for change in PVC burden and with serial echocardiography. RESULTS: Overall, 120 patients met inclusion criteria (mean: 56.5 ± 14.6 years, 54.2% female) with 53 on beta-blockers or calcium channel blockers (BBs/CCBs), 27 on Class I or III antiarrhythmic drugs (AADs), and 40 patients treated conservatively. Median initial PVC burden ranged from 15.5% to 20.6%. The median relative reduction of PVCs was 32.7%, 30.5%, and 81.3%, in the conservative therapy, BBs/CCBs, and AADs cohorts, respectively. AADs had greater PVC reduction compared with BBs/CCBs (p = 0.017) and conservative therapy (p = 0.045). PVC reduction to <1% was comparable across groups at 35.0%, 17.0%, 33.3%, respectively. Four patients (4/120, 3.3%) developed left ventricular dysfunction. Rates of adverse drug reactions and medication discontinuation were similar between groups, with no serious adverse events noted. CONCLUSION: In patients with idiopathic frequent PVCs, BB, and CCB have limited effectiveness in PVC reduction. Class I and III AADs have superior effectiveness for medical therapy in symptomatic patients, but only achieved complete PVC resolution suppression in one-third of patients.

Establishing reference ranges for ambulatory electrocardiography parameters: meta-analysis.

OBJECTIVE: Despite the widespread and increasing use of ambulatory electrocardiography (ECG), there is no consensus on reference ranges for ambulatory electrocardiogram parameters to guide interpretation. We sought to determine population distribution-based reference ranges for parameters measured during ambulatory electrocardiogram in healthy adults, based on existing literature. METHODS: We searched multiple databases from 1950 to 2020. Articles reporting original data from ≥24-hour ambulatory electrocardiogram monitoring in healthy adults were included. Data extraction and synthesis were performed according to Meta-analysis of Observational Studies in Epidemiology guidelines. The prevalence/mean and SD for common parameters (sinus pauses, conduction abnormalities and ectopy) were extracted by age group (18-39, 40-59, 60-79 and 80+ years). RESULTS: We identified 33 studies involving 6466 patients. Sinus pauses of >3 s were rare (pooled prevalence <1%) across all ages. Supraventricular ectopy of >1000/24 hours increased with age, from 0% (95% CI 0% to 0%) in those aged 18-39 years to 6% (95% CI 0% to 17%) in those aged 60-79 years. Episodes of supraventricular tachycardia increased from 3% (95% CI 1% to 6%) in those aged 18-39 years to 28% (95% CI 9% to 52%) in those aged 60-79 years. Ventricular ectopy of >1000/24 hours also increased with age, from 1% (95% CI 0% to 2%) in those aged 18-39 years to 5% (95% CI 1% to 10%) in those aged 60-79 years. Episodes of non-sustained ventricular tachycardia ranged from 0% (95% CI 0% to 1%) in those aged 18-39 years to 2% (95% CI 0% to 5%) in those aged 60-79 years. CONCLUSION: Despite the limitations of existing published data, this meta-analysis provides evidence-based reference ranges for ambulatory electrocardiogram parameters and highlights significant age-dependent differences that should be taken into account during interpretation.

Association Between Patient and Physician Sex and Physician-Estimated Stroke and Bleeding Risks in Atrial Fibrillation.

BACKGROUND: Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain. METHODS: We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male). RESULTS: Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians. CONCLUSIONS: Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation.

Assessment of cardiovascular risk and preparticipation screening protocols in masters athletes: the Masters Athlete Screening Study (MASS): a cross-sectional study.

BACKGROUND: Underlying coronary artery disease (CAD) is the primary cause of sudden cardiac death in masters athletes (>35 years). Preparticipation screening may detect cardiovascular disease; however, the optimal screening method is undefined in this population. The Physical Activity Readiness Questionnaire for Everyone (PAR-Q+) and the American Heart Association (AHA) Preparticipation Screening Questionnaire are often currently used; however, a more comprehensive risk assessment may be required. We sought to ascertain the cardiovascular risk and to assess the effectiveness of screening tools in masters athletes. METHODS: This cross-sectional study performed preparticipation screening on masters athletes, which included an ECG, the AHA 14-element recommendations and Framingham Risk Score (FRS). If the preparticipation screening was abnormal, further evaluations were performed. The effectiveness of the screening tools was determined by their positive predictive value (PPV). RESULTS: 798 athletes were included in the preparticipation screening analysis (62.7% male, 54.6±9.5 years, range 35-81). The metabolic equivalent task hours per week was 80.8±44.0, and the average physical activity experience was 35.1±14.8 years. Sixty-four per cent underwent additional evaluations. Cardiovascular disease was detected in 11.4%, with CAD (7.9%) being the most common diagnosis. High FRS (>20%) was seen in 8.5% of the study population. Ten athletes were diagnosed with significant CAD; 90% were asymptomatic. A high FRS was most indicative of underlying CAD (PPV 38.2%). CONCLUSION: Masters athletes are not immune to elevated cardiovascular risk and cardiovascular disease. Comprehensive preparticipation screening including an ECG and FRS can detect cardiovascular disease. An exercise stress test should be considered in those with risk factors, regardless of fitness level.

Implementation of an emergency department atrial fibrillation and flutter pathway improves rates of appropriate anticoagulation, reduces length of stay and thirty-day revisit rates for congestive heart failure.

OBJECTIVES: An evidence-based emergency department (ED) atrial fibrillation and flutter (AFF) pathway was developed to improve care. The primary objective was to measure rates of new anticoagulation (AC) on ED discharge for AFF patients who were not AC correctly upon presentation. METHODS: This is a pre-post evaluation from April to December 2013 measuring the impact of our pathway on rates of new AC and other performance measures in patients with uncomplicated AFF solely managed by emergency physicians. A standardized chart review identified demographics, comorbidities, and ED treatments. The primary outcome was the rate of new AC. Secondary outcomes were ED length of stay (LOS), referrals to AFF clinic, ED revisit rates, and 30-day rates of return visits for congestive heart failure (CHF), stroke, major bleeding, and death. RESULTS: ED AFF patients totalling 301 (129 pre-pathway [PRE]; 172 post-pathway [POST]) were included; baseline demographics were similar between groups. The rates of AC at ED presentation were 18.6% (PRE) and 19.7% (POST). The rates of new AC on ED discharge were 48.6 % PRE (95% confidence interval [CI] 42.1%-55.1%) and 70.2% POST (62.1%-78.3%) (20.6% [p<0.01; 15.1-26.3]). Median ED LOS decreased from 262 to 218 minutes (44 minutes [p<0.03; 36.2-51.8]). Thirty-day rates of ED revisits for CHF decreased from 13.2% to 2.3% (10.9%; p<0.01; 8.1%-13.7%), and rates of other measures were similar. CONCLUSIONS: The evidence-based pathway led to an improvement in the rate of patients with new AC upon discharge, a reduction in ED LOS, and decreased revisit rates for CHF.

Use of Evidence-Based Therapy for Cardiovascular Risk Factors in Canadian Outpatients With Atrial Fibrillation: From the Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation (FREEDOM AF) and Co-ordinated National Network to Engage Physicians in the Care and Treatment of Patients With Atrial Fibrillation (CONNECT AF).

Using data collected from 2 national atrial fibrillation (AF) primary care physician chart audits (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation [FREEDOM AF] and Co-ordinated National Network to Engage Physicians in the Care and Treatment of Patients With Atrial Fibrillation [CONNECT AF]), we evaluated the frequency of, and factors associated with, the use of cardiovascular (CV) evidence-based therapies in Canadian AF outpatients with at least 1 CV risk factor or co-morbidity. Of the 11,264 patients enrolled, 9,495 (84.3%) were eligible for one or more CV evidence-based therapies. The proportions of patients with AF receiving all eligible guideline-recommended therapies were 40.8% of patients with coronary artery disease, 48.9% of patients with diabetes mellitus, 40.2% of patients with heart failure, 96.7% of patients with hypertension, and 55.1% of patients with peripheral arterial disease. Factors that were independently associated with nonreceipt of all indicated evidence-based therapies included sinus rhythm rather than AF at baseline and liver disease. In conclusion, although most Canadian outpatients with AF have CV risk factors or co-morbidities, a substantial portion of these patients did not receive all guideline-recommended therapies. These findings suggest that there is an opportunity to improve the quality of care for patients with AF in Canada.

Detecting Underlying Cardiovascular Disease in Young Competitive Athletes.

BACKGROUND: Sudden cardiac death (SCD) is frequently the first manifestation of underlying cardiovascular disease in young competitive athletes (YCAs), yet there are no Canadian guidelines for preparticipation screening in this population. The goal of this study was to determine the prevalence of potentially lethal cardiovascular disease in a sample of Canadian YCAs by comparing 2 screening strategies. METHODS: We prospectively screened 1419 YCAs in British Columbia, Canada (age 12-35 years). We initially screened 714 YCAs using the American Heart Association 12-element recommendations, physical examination, and electrocardiogram (ECG) examination (phase 1). This strategy yielded a high number of false positive results; 705 YCAs were subsequently screened using a novel SportsCardiologyBC (SCBC) questionnaire and ECG examination in the absence of a physical examination (phase 2). RESULTS: Overall, 7 YCAs (0.52%) were found to have clinically significant diagnoses associated with SCD (4 pre-excitation, 1 long QT syndrome, 1 mitral valve prolapse, 1 hypertrophic cardiomyopathy). Six of the 7 athletes (85.7%) with disease possessed an abnormal ECG. Conversely, only 2 had a positive personal or family history (1 athlete had an abnormal ECG and family history). The SCBC questionnaire and protocol (phase 2) was associated with fewer false positive screens; 3.7% (25 of 679) compared with 8.1% (55 of 680) in phase 1 (P = 0.0012). CONCLUSIONS: The prevalence of conditions associated with SCD in a cohort of Canadian YCAs was comparable with American and European populations. The SCBC questionnaire and protocol were associated with fewer false positive screens. The ECG identified most of the positive cases irrespective of screening strategy used.

Comparison of Rates of Coronary Angiography and Combined Testing Procedures in Patients Seen in the Emergency Room With Chest Pain (But No Objective Acute Coronary Syndrome Findings) Having Coronary Computed Tomography Versus Exercise Stress Testing.

Coronary computed tomography angiography (CCTA) appears comparable to standard care, including exercise stress testing (EST), in diagnosing acute coronary syndrome in emergency department (ED) patients with chest pain but may increase downstream testing. The objective of this study was to investigate rates of post-CCTA versus post-EST testing for (1) invasive angiography and (2) all combined cardiac testing. This was a retrospective cohort study performed at 2 urban Canadian EDs involving patients aged up to 65 years with chest pain but no objective ACS findings that were evaluated with CCTA or EST at the physician's discretion. The primary outcome was the proportion of patients who had 30-day invasive angiography in each group; secondary outcomes included all subsequent 30-day cardiac testing, including nuclear medicine scanning. From July 1, 2012, to June 30, 2014, we collected 1,700 patients: 521 CCTA and 1,179 EST. Demographics and risk factors were similar in both cohorts. In the following 30 days, 30 CCTA (5.8%) and 297 EST (25.2%) patients underwent any type of additional cardiac testing (difference 19.4%, 95% CI 16.0 to 22.6), whereas 12 CCTA (2.3%) and 20 EST patients (1.7%) underwent angiography (difference 0.6%, 95% CI -0.8% to 2.6%). No patients in either group died or had a myocardial infarction within 30 days. For ED patients with chest pain who underwent brief observation, CCTA and EST had similar 30-day angiography rates, but CCTA patients underwent significantly less overall cardiac investigations.

Safety and efficiency of outpatient versus emergency department-based coronary CT angiography for evaluation of patients with potential ischemic chest pain.

BACKGROUND: While coronary CT angiography (coronary CTA) may be comparable to standard care in diagnosing acute coronary syndrome (ACS) in emergency department (ED) chest pain patients, it has traditionally been obtained prior to ED discharge and a strategy of delayed outpatient coronary CTA following an ED visit has not been evaluated. OBJECTIVE: To investigate the safety of discharging stable ED patients and obtaining outpatient CCTA. METHODS: At two urban Canadian EDs, patients up to 65 years with chest pain but no findings indicating presence of ACS were further evaluated depending upon time of presentation: (1) ED-based coronary CTA during normal working hours, (2) or outpatient coronary CTA within 72 hours at other times. All data were collected prospectively. The primary outcome was the proportion of patients who had an outpatient coronary CTA ordered and had a predefined major adverse cardiac event (MACE) between ED discharge and outpatient CT; secondary outcome was the ED length of stay in both groups. RESULTS: From July 1, 2012 to June 30, 2014, we enrolled 521 consecutive patients: 350 with outpatient CT and 171 with ED-based CT. Demographics and risk factors were similar in both cohorts. No outpatient CT patients had a MACE prior to coronary CTA. (0.0%, 95% CI 0 to 0.9%) The median length of stay for ED-based evaluation was 6.6 hours (interquartile range 5.4 to 8.3 hours) while the outpatient group had a median length of stay of 7.0 hours (IQR 6.0 to 9.8 hours, n.s.). CONCLUSIONS: In ED chest pain patients with a low risk of ACS, performing coronary CTA as an outpatient may be a safe strategy.

There Are Sex Differences in the Demographics and Risk Profiles of Emergency Department (ED) Patients With Atrial Fibrillation and Flutter, but no Apparent Differences in ED Management or Outcomes.

OBJECTIVES: In non-emergency department (ED) settings, women with atrial fibrillation and flutter (AFF) have different presentations, treatments, and outcomes than men: they are older, less likely to be treated with rhythm control strategies or appropriate anticoagulation, and more likely to have strokes. This has not been investigated in ED patients. METHODS: Records from consecutive ED patients from January 1 to December 31, 2009, with electrocardiogram-proven AFF at two urban hospitals were collected. Review of administrative and clinical data identified patient demographics, clinical characteristics, comorbidities, and ED treatments. The regional ED database was queried to determine 30-day and 1-year follow-up visits, and the provincial vital statistics database was referenced to obtain 30-day and 1-year mortality; all outcomes were stratified by sex. The primary outcome, which reflected overall appropriateness of ED care, was the proportion of patients who were discharged home at their index ED visits, who then had unscheduled 30-day ED revisits. Secondary outcomes included the proportion of eligible patients who underwent acute rhythm control strategies and the proportion of high-risk patients who had previously inadequately anticoagulation strategies corrected by the emergency physician. Additional outcomes included the ED length of stay (LOS) and 30-day and 1-year rates of stroke and death. RESULTS: A total of 1,112 records were reviewed: 470 women (42.3%) and 642 men. Women were a median 8 years (interquartile range = 3 to 13 years) older than men, had higher rates of cardiovascular comorbidities, and were more likely to present with atypical symptoms such as weakness or dyspnea. On their index ED visits, 50.2% of women and 41.3% of men were admitted. At 30 days, 39 of 234 (16.7%) women and 55 of 377 (14.6%) men who were discharged at their index ED visits had made revisits, for a risk difference of 2.1% (95% confidence interval = -3.9% to 8.5%). There were no apparent sex differences in the use of acute rhythm control or in the appropriateness of anticoagulation decisions. ED LOS was similar between women and men, as were 30-day and 1-year stroke or death rates. CONCLUSIONS: Female ED AFF patients were older, had more comorbidities, and were more likely to be admitted. However, the overall management and outcomes, including 30-day revisits, appeared to be similar to that of males, indicating that there appeared to be little sex-based discrepancy in ED care and outcomes.

Risk stratification and stroke prevention therapy care gaps in Canadian atrial fibrillation patients (from the Co-ordinated National Network to Engage Physicians in the Care and Treatment of Patients With Atrial Fibrillation chart audit).

The objectives of this national chart audit (January to June 2013) of 6,346 patients with atrial fibrillation (AF; ≥18 years without a significant heart valve disorder) from 647 primary care physicians were to (1) describe the frequency of stroke and bleed risk assessments in patients with nonvalvular AF by primary care physicians, including the accuracy of these assessments relative to established predictive indexes; (2) outline contemporary methods of anticoagulation used; and (3) report the time in the therapeutic range among patients prescribed warfarin. An annual stroke risk assessment was not undertaken in 15% and estimated without a formal risk tool in 33%; agreement with CHADS2 score estimation was seen in 87% of patients. Major bleeding risk assessment was not undertaken in 25% and estimated without a formal risk tool in 47%; agreement with HAS-BLED score estimation was observed in 64% with physician overestimation in 26% of patients. Antithrombotic therapy included warfarin (58%), dabigatran (22%), rivaroxaban (14%), and apixaban (<1%). Among warfarin-treated patients, the median international normalized ratio was 2.4 and time in therapeutic range (TTR) was 73%; however, the TTR was <50% in 845 (25%), 50% to 69% in 674 (20%), and ≥70% in 1,827 (55%) patients. In conclusion, we describe a contemporary real-world elderly population with AF at important risk for stroke. There is apparent overestimation of bleeding risk in many patients. Warfarin was the dominant stroke prevention treatment; however, the suggested TTR target was achieved in only 55% of these patients.

Emergency Department Patients With Atrial Fibrillation or Flutter and an Acute Underlying Medical Illness May Not Benefit From Attempts to Control Rate or Rhythm.

STUDY OBJECTIVE: Although the management and outcomes of emergency department (ED) patients with atrial fibrillation or flutter have been explored, such studies have typically excluded patients with acute underlying medical illnesses. We seek to describe the ED treatment and outcomes of these complex patients with atrial fibrillation or flutter. METHODS: This retrospective descriptive cohort study used an ECG database from 2 urban EDs to identify consecutive ED patients with an ECG demonstrating atrial fibrillation or flutter from January 1, 2009, to December 31, 2009. We categorized patients with atrial fibrillation or flutter as "complex" according to prespecified criteria and then grouped them as being managed with rate or rhythm control attempts, or not. The primary outcome was safety of rate or rhythm control, measured by whether patients had a predefined adverse event or not. The secondary outcome was the success of rate or rhythm control, defined as rate control decreasing the pulse rate by 20 beats/min and successful rhythm control, both within 4 hours of treatment initiation. Descriptive statistics were used to compare the 2 groups. RESULTS: Four hundred sixteen complex patients with atrial fibrillation or flutter were identified. Patients managed with rate or rhythm control were similar in all baseline characteristics and illness distribution to patients who were not managed in this manner. The 135 patients with attempted rate control (105) or rhythm control (30) had 55 adverse events (40.7%; 95% confidence interval [CI] 32.5% to 49.5%), whereas the 281 patients not managed with rate or rhythm control had 20 adverse events (7.1%; 95% CI 4.5% to 10.9%), for a risk difference of 33.6% (95% CI 24.3% to 42.5%) and a relative risk of 5.7 (95% CI 3.6 to 9.1). Twenty of 105 patients (19.1%; 95% CI 12.3% to 28.1%) were successfully rate controlled, whereas 4 of 30 (13.3%; 95% CI 4.4% to 31.6%) were successfully rhythm controlled. CONCLUSION: In ED patients with complex atrial fibrillation or flutter, attempts at rate and rhythm control are associated with a nearly 6-fold higher adverse event rate than that for patients who are not managed with rate or rhythm control. Success rates of rate or rhythm control attempts appear low.

Reduced iodine load with CT coronary angiography using dual-energy imaging: a prospective randomized trial compared with standard coronary CT angiography.

BACKGROUND: There is concern regarding the administration of iodinated contrast to patients with impaired renal function because of the increased risk of contrast-induced nephropathy. OBJECTIVE: Evaluate image quality and feasibility of a protocol with a reduced volume of iodinated contrast and utilization of dual-energy coronary CT angiography (DECT) vs a standard iodinated contrast volume coronary CT angiography protocol (SCCTA). METHODS: A total of 102 consecutive patients were randomized to SCCTA (n = 53) or DECT with rapid kVp switching (n = 49). Eighty milliliters and 35 mL of iodinated contrast were administered in the SCCTA and DECT cohorts, respectively. Two readers measured signal and noise in the coronary arteries; signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. A 5-point signal/noise Likert scale was used to evaluate image quality; scores of <3 were nondiagnostic. Agreement was assessed through kappa analyses. RESULTS: Demographics and radiation dose were not significantly different; there was no difference in CNR between both cohorts (P = .95). A significant difference in SNR between the groups (P = .02) lost significance (P = .13) when adjusted for body mass index. The median Likert score was inferior for DECT for reader 1 (3.6 ± 0.6 vs 4.3 ± 0.6; P < .001) but not reader 2 (4.1 ± 0.6 vs 4.3 ± 0.5; P = .06). Agreement in diagnostic interpretability in the DECT and SCCTA groups was 91% (95% confidence interval, 86%-100%) and 96% (95% confidence interval, 90%-100%), respectively. CONCLUSION: DECT resulted in inferior image quality scores but demonstrated comparable SNR, CNR, and rate of diagnostic interpretability without a radiation dose penalty while allowing for >50% reduction in contrast volume compared with SCCTA.

Assessment of sex differences in plaque morphology by coronary computed tomography angiography--are men and women the same?

PURPOSE: The objective of this study was to assess whether sex differences exist in plaque burden and plaque subtype as assessed by coronary computed tomography angiography (CCTA). METHODS: The study cohort included 937 consecutive patients who underwent CCTA between 2008 and 2010. Stenosis was quantified using the Society of Cardiovascular Computed Tomography stenosis grading scale and a total stenosis score (TSS) was generated. Plaque morphology (PM) was reported as predominantly calcified (CP), noncalcified (NCP), or mixed (MP) plaque, and CP, NCP, and MP percentages were calculated. RESULTS: On multivariate analysis, men were significantly more likely to have plaque (65.9% of men vs. 44.6% of women, p<0.001), at least one segment with ≥50% stenosis (22.7% of men vs. 10.3% of women, p<0.001) and higher TSS (mean score=2.81 for men vs. 1.58 for women, p<0.001). Sex was the strongest predictor in all models (odds ratio [OR]=2.55, 95% confidence interval [CI] 1.78-3.67, p<0.001 for any plaque; OR=2.48, 95% CI 1.48-4.16, p<0.01 for segments with ≥50% stenosis; ß=1.46, 95% CI 0.69-2.22, p<0.001 for TSS). Among patients with coronary plaque present, no significant sex differences in PM were found. CONCLUSIONS: Sex was the strongest risk factor for the presence and extent of plaque. Significant sex differences in PM did not exist.

Early atherosclerosis detection in asymptomatic patients: a comparison of carotid ultrasound, coronary artery calcium score, and coronary computed tomography angiography.

BACKGROUND: Detailed multimodality assessment of subclinical atherosclerosis in asymptomatic subjects referred for risk stratification has not been performed. We analyzed the detection of early atherosclerosis using 3 imaging modalities: coronary artery calcium (CAC) scoring, carotid ultrasound (US), and coronary computed tomography angiography (CCTA). METHODS: Asymptomatic subjects free of known vascular disease scheduled to undergo a carotid US for risk stratification were invited to undergo CCTA/CAC. Subjects taking lipid-lowering medication were excluded. All images were assessed by experienced core laboratory personnel. Carotid intima media thickness ≥ 75th percentile for age and sex, CAC > 0, and detection of either carotid or coronary artery plaque were indicators of atherosclerosis. RESULTS: Fifty patients were included with a median age of 53 years. Atherosclerosis was observed in 28%, 78%, and 90% of subjects using CAC, CCTA, and carotid US, respectively. All subjects showed atherosclerosis on at least 1 modality. In 36 patients with a CAC score = 0, 69% and 86% had atherosclerosis on CCTA and carotid US, respectively. CONCLUSIONS: In this detailed analysis, all subjects identified to warrant further risk stratification had subclinical atherosclerosis on at least 1 imaging modality. Concordance between modalities was highly variable, dependent on the specific definition of atherosclerosis used. Carotid US and CCTA detection of plaque were significantly more sensitive than CAC > 0 in this middle-aged population. Considering the prevalence of subclinical disease on carotid US and CCTA, the threshold at which to treat warrants further research.

Missed opportunities for appropriate anticoagulation among emergency department patients with uncomplicated atrial fibrillation or flutter.

STUDY OBJECTIVE: Emergency department (ED) patients with atrial fibrillation or flutter are at risk of stroke, and guidelines recommend anticoagulation for patients with increased cardiovascular risk. Emergency physicians have a unique opportunity to provide appropriate anticoagulation for such patients, and we wished to investigate whether this was accomplished. METHODS: This retrospective cohort study used a database from 2 urban EDs to identify consecutive patients with an ED discharge diagnosis of atrial fibrillation or flutter from April 1, 2006, to March 31, 2010, who were managed solely by the emergency physician. Comorbidities, rhythms, and management were obtained by chart review, and complicated patients (those with an acute underlying medical condition) were excluded by predefined criteria. Patient medications on ED presentations were obtained through the provincial Pharmanet database. Patients were stratified into CHADS 2 (congestive heart failure, hypertension, age > 75, diabetes, stroke/transient ischemic attack) scores, and the primary outcome was the proportion of higher-risk (CHADS 2 score >0) patients who were discharged home with the incorrect anticoagulation by the emergency physician. The secondary outcome was the number of lower-risk (CHADS 2=0) patients who began receiving warfarin by the emergency physician orders. The regional ED database was interrogated to ascertain the number of patients who had a stroke at 30 days. RESULTS: Consecutive patients (1,090) were enrolled and 732 were discharged home with no cardiology consultation (657 fibrillation and 75 flutter). Of 151 higher-risk (CHADS 2 score >0) patients who should have been anticoagulated, 80 (53.0%; 95% confidence interval 44.7% to 61.0%) were discharged home from the ED without appropriate anticoagulation. In this group, 1 patient had an ischemic stroke at 24 days. Among 300 lower-risk patients (CHADS 2 score=0), 25 (8.3%; 95% confidence interval 5.6% to 12.2%) had warfarin initiated. CONCLUSION: In this cohort of ED patients with uncomplicated atrial fibrillation or flutter who were discharged without cardiology involvement, many were not appropriately anticoagulated before ED arrival, and more than half of such patients did not appear to have corrective measures initiated by the emergency physician. This may represent a potential opportunity to improve patient care and outcomes.

A prospective randomized trial comparing image quality, study interpretability, and radiation dose of narrow acquisition window with widened acquisition window protocols in prospectively ECG-triggered coronary computed tomography angiography.

BACKGROUND: Prospectively triggered coronary computed tomography angiography (CTA) is commonly performed with a widened acquisition window to provide flexibility in image reconstruction. OBJECTIVE: We conducted a randomized controlled trial to determine whether the use of a narrow acquisition window in prospectively triggered coronary CTA would allow lower radiation dose while preserving image quality and interpretability. METHODS: Prospective 2-center 2- platform randomized trial that evaluated 205 consecutive patients 96 with widened acquisition (WA) and 109 narrow acquisition (NA) referred for coronary CTA in sinus rhythm and heart rate <65 beats/min. Patients scanned with WA had phases reconstructed at 5% intervals, and each phase was assigned an individual study ID. Images were reviewed with individual phase reconstructions interpreted randomly by 2 level 3 readers with a third for consensus. Images were evaluated with a 5-point Likert scale on a per-vessel basis (best score on any phase). Scores were then dichotomized into diagnostic (score 3-5) compared with nondiagnostic (score 1-2). Readers also reported obstructive coronary artery disease on a per-patient basis. Agreement for the diagnosis of obstructive disease and per-artery interpretability was performed. Signal and noise measurements were also performed. RESULTS: No difference in demographics between groups (P = NS). The signal-to-noise ratio was comparable 12.99 ± 3.4 NA and 12.53 ± 4.13 for the WA (P = 0.45). The median effective dose was 1.78 mSv for NA compared with 3.26 mSv for WA (P < 0.001). Image quality, diagnostic interpretability, interreader agreement, and downstream testing were not significantly different between the 2 groups (P= NS for all). CONCLUSIONS: Coronary CTA with NA resulted in a 47% lower radiation dose without significant difference in study interpretability or image quality or increased downstream resource use or testing.

Safety and efficiency of calcium channel blockers versus beta-blockers for rate control in patients with atrial fibrillation and no acute underlying medical illness.

OBJECTIVES: Many patients with atrial fibrillation (AF) are not candidates for rhythm control and may require rate control, typically with beta-blocking (BB) or calcium channel blocking (CCB) agents. Although these patients appear to have a low 30-day rate of stroke or death, it is unclear if one class of agent is safer or more effective. The objective was to determine whether BBs or CCBs would have a lower hospital admission rate and to measure 30-day safety outcomes including stroke, death, and emergency department (ED) revisits. METHODS: This retrospective cohort study used a database from two urban EDs to identify consecutive patients with ED discharge diagnoses of AF from April 1, 2006, to March 31, 2010. Comorbidities, rhythms, management, and immediate outcomes were obtained by manual chart review, and patients with acute underlying medical conditions were excluded by predefined criteria. Patients managed only with rate control agents were eligible for review, and patients receiving BB agents were compared to those receiving CCB agents. The primary outcome was the proportion of patients requiring hospital admission; secondary outcomes included the ED length of stay (LOS), the proportion of patients having adverse events, the proportion of patients returning within 7 or 30 days, and the number of patients having a stroke or dying within 30 days. RESULTS: A total of 259 consecutive patients were enrolled, with 100 receiving CCBs and 159 receiving BBs. Baseline demographics and comorbidities were similar. Twenty-seven percent of BB patients were admitted, and 31.0% of CCB patients were admitted (difference = 4.0%, 95% confidence interval [CI] = -7.7% to 16.1%), and there were no significant differences in ED LOS, adverse events, or 7- or 30-day ED revisits. One patient who received metoprolol had a stroke, and one patient who received diltiazem died within 30 days. CONCLUSIONS: In this cohort of ED patients with AF and no acute underlying medical illness who underwent rate control only, patients receiving CCBs had similar hospital admission rates to those receiving BBs, while both classes of medications appeared equally safe at 30 days. Both CCBs and BBs are acceptable options for rate control.

Cardiovascular risk among stable individuals suspected of having coronary artery disease with no modifiable risk factors: results from an international multicenter study of 5262 patients.

PURPOSE: To assess the prevalence, extent, severity, and risk of coronary artery disease (CAD) in patients suspected of having CAD but with no medically modifiable risk factors. MATERIALS AND METHODS: Institutional review board approval or waiver of consent was obtained at each center. This study was HIPAA compliant. From an international multicenter cohort study of 27 125 subjects undergoing coronary computed tomographic (CT) angiography from 12 centers, 5262 patients without known CAD and without modifiable risk factors were identified. CAD severity was defined as none (0%), mild (1%-49%), or obstructive (≥ 50%) on a per-patient, per-vessel, and per-segment basis. CAD presence, extent, and severity were related to incidence of major adverse cardiovascular event (MACE) by using Cox proportional hazards models. RESULTS: At a mean follow-up of 2.3 years ± 1.2 (standard deviation), MACE occurred in 106 patients. CAD was common for nonobstructive (n = 1452, 27%) and obstructive (n = 629, 12%) CAD. In risk-adjusted analysis, per-patient obstructive CAD (hazard ratio [HR], 6.64; 95% confidence interval [CI]: 3.68, 12.00; P ≤ .001) was related to MACE. MACE was associated with a dose-response relationship to the number of vessels exhibiting obstructive CAD, increasing risk for obstructive one-vessel (HR, 6.11; 95% CI: 3.22, 11.6; P ≤ .001), two-vessel (HR, 5.86; 95% CI: 2.75, 12.5; P ≤ .0001), or three-vessel or left main (HR, 11.69; 95% CI: 5.38, 25.4; P ≤ .001) CAD. The increased hazard for MACE of obstructive disease holds true for symptomatic (HR, 11.9; 95% CI: 4.81, 29.6; P ≤ .001) and asymptomatic (HR, 6.3; 95% CI: 2.4, 16.7; P ≤ .001) patients. No CAD at coronary CT angiography was associated with a low annualized MACE rate: 0.31% versus 2.06% with obstructive disease. CONCLUSION: Among individuals suspected of having CAD but without modifiable risk factors, CAD is common, with significantly increased hazards for MACE and mortality.