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.

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.

Cardiac MRI assessment of the right ventricle pre-and post-kidney transplant.

Worsening renal function in chronic kidney disease correlates with worsening right ventricular (RV) systolic function. We evaluated the association between kidney transplantation (KT) and RV structure and systolic function, and the relationships between RV and left ventricular (LV) changes, blood pressure, and specific cardiac biomarkers, in patients with end-stage kidney disease using cardiac magnetic resonance imaging (CMR). In this prospective, multi-centre, cohort study, 39 adult patients on dialysis receiving KT and 42 patients eligible for, but not yet receiving KT, were recruited. CMR was performed at baseline, and repeated at 12 months. Among 81 patients (mean age 51 years, 30% female), RV end-diastolic volume index (RVEDVi), end-systolic volume index (RVESVi), mass index (RVMi), and ejection fraction (RVEF) did not change significantly within either the dialysis or KT group over 12 months (all p ≥ 0.10). There were no significant differences in the 12-month changes of these parameters between the dialysis and KT groups (all p ≥ 0.10). RVMI demonstrated positive correlations with NT-proBNP and systolic blood pressure, but not GDF-15, at baseline and at 12 months. Changes in RVEDVi, RVESVi, and RVEF were positively correlated with changes in LVEDVi, LVESVi, and LVEF, respectively over 12 months (Spearman r = 0.72, 0.52, and 0.41; all p < 0.001), but not mass index (Spearman r = 0.20, p = 0.078). In conclusion, there were no significant changes in RV mass, volumes, or systolic function 12 months after KT, as compared with continuation of dialysis. The associations between RV and LV remodeling may suggest similar underlying pathophysiologic mechanisms.

Objective Risk Assessment vs Standard Care for Acute Coronary Syndromes: A Randomized Clinical Trial.

Importance: Although international guidelines recommend use of the Global Registries of Acute Coronary Events (GRACE) risk score (GRS) to guide acute coronary syndrome (ACS) treatment decisions, the prospective utility of the GRS in improving care and outcomes is unproven. Objective: To assess the effect of routine GRS implementation on guideline-indicated treatments and clinical outcomes of hospitalized patients with ACS. Design, Setting, and Participants: Prospective cluster (hospital-level) randomized open-label blinded end point (PROBE) clinical trial using a multicenter ACS registry of acute care cardiology services. Fixed sampling of the first 10 patients within calendar month, with either ST-segment elevation or non-ST-segment elevation ACS. The study enrolled patients from June 2014 to March 2018, and data were analyzed between February 2020 and April 2020. Interventions: Implementation of routine risk stratification using the GRS and guideline recommendations. Main Outcomes and Measures: The primary outcome was a performance score based on receipt of early invasive treatment, discharge prescription of 4 of 5 guideline-recommended pharmacotherapies, and cardiac rehabilitation referral. Clinical outcomes included a composite of all-cause death and/or myocardial infarction (MI) within 1 year. Results: This study enrolled 2318 patients from 24 hospitals and was stopped prematurely owing to futility. Of the patients enrolled, median age was 65 years (interquartile range, 56-74 years), 29.5% were women (n = 684), and 62.9% were considered high risk (n = 1433). Provision of all 3 measures among high-risk patients did not differ between the randomized arms (GRS: 424 of 717 [59.9%] vs control: 376 of 681 [55.2%]; odds ratio [OR], 1.04; 95% CI, 0.63-1.71; P = .88). The provision of early invasive treatment was increased compared with the control arm (GRS: 1042 of 1135 [91.8%] vs control: 989 of 1183 [83.6%]; OR, 2.26; 95% CI, 1.30-3.96; P = .004). Prescription of 4 of 5 guideline-recommended pharmacotherapies (GRS: 864 of 1135 [76.7%] vs control: 893 of 1183 [77.5%]; OR, 0.97; 95% CI, 0.68-1.38) and cardiac rehabilitation (GRS: 855 of 1135 [75.1%] vs control: 861 of 1183 [72.8%]; OR, 0.68; 95% CI, 0.32-1.44) were not different. By 12 months, GRS intervention was not associated with a significant reduction in death or MI compared with the control group (GRS: 96 of 1044 [9.2%] vs control: 146 of 1087 [13.4%]; OR, 0.66; 95% CI, 0.38-1.14). Conclusions and Relevance: Routine GRS implementation in cardiology services with high levels of clinical care was associated with an increase in early invasive treatment but not other aspects of care. Low event rates and premature study discontinuation indicates the need for further, larger scale randomized studies. Trial Registration: anzctr.org.au Identifier: ACTRN12614000550606.

Assessment of left ventricular function by CMR versus MUGA scans in breast cancer patients receiving trastuzumab: a prospective observational study.

Little is known about the comparison of multiple-gated acquisition (MUGA) scanning with cardiovascular magnetic resonance (CMR) for serial monitoring of HER2+ breast cancer patients receiving trastuzumab. The association of cardiac biomarkers with CMR left ventricular (LV) function and volume is also not well studied. Our objectives were to compare CMR and MUGA for left ventricular ejection fraction (LVEF) assessment, and to examine the association between changes in brain natriuretic peptide (NT-BNP) and troponin-I and changes in CMR LV function and volume. This prospective longitudinal two-centre cohort study recruited HER2+ breast cancer patients between January 2010 and December 2013. MUGA, CMR, NT-BNP and troponin-I were performed at baseline, 6, 12, and 18 months after trastuzumab initiation. In total, 41 patients (age 51.7 ± 10.8 years) were enrolled. LVEF comparison between MUGA and CMR demonstrated weak agreement (Lin's correlation coefficient r = 0.46, baseline; r = 0.29, 6 months; r = 0.42, 12 months; r = 0.39, 18 months; all p < 0.05). Bland-Altman plots demonstrated wide LVEF agreement limits (pooled agreement limits 3.0 ± 6.2). Both modalities demonstrated significant LVEF decline at 6 and 12 months from baseline, concomitant with increased LV volumes on CMR. Changes in NT-BNP correlated with changes in LV diastolic volume at 12 and 18 months (p < 0.05), and LV systolic volume at 18 months (p < 0.05). Changes in troponin-I did not correlate with changes in LV function or volume at any timepoint. In conclusion, CMR and MUGA LVEF are not interchangeable, warranting selection and utility of one modality for serial monitoring. CMR is useful due to less radiation exposure and accuracy of LV volume measurements. Changes in NT-BNP correlated with changes in LV volumes.

Multimorbidity and survival for patients with acute myocardial infarction in England and Wales: Latent class analysis of a nationwide population-based cohort.

BACKGROUND: There is limited knowledge of the scale and impact of multimorbidity for patients who have had an acute myocardial infarction (AMI). Therefore, this study aimed to determine the extent to which multimorbidity is associated with long-term survival following AMI. METHODS AND FINDINGS: This national observational study included 693,388 patients (median age 70.7 years, 452,896 [65.5%] male) from the Myocardial Ischaemia National Audit Project (England and Wales) who were admitted with AMI between 1 January 2003 and 30 June 2013. There were 412,809 (59.5%) patients with multimorbidity at the time of admission with AMI, i.e., having at least 1 of the following long-term health conditions: diabetes, chronic obstructive pulmonary disease or asthma, heart failure, renal failure, cerebrovascular disease, peripheral vascular disease, or hypertension. Those with heart failure, renal failure, or cerebrovascular disease had the worst outcomes (39.5 [95% CI 39.0-40.0], 38.2 [27.7-26.8], and 26.6 [25.2-26.4] deaths per 100 person-years, respectively). Latent class analysis revealed 3 multimorbidity phenotype clusters: (1) a high multimorbidity class, with concomitant heart failure, peripheral vascular disease, and hypertension, (2) a medium multimorbidity class, with peripheral vascular disease and hypertension, and (3) a low multimorbidity class. Patients in class 1 were less likely to receive pharmacological therapies compared with class 2 and 3 patients (including aspirin, 83.8% versus 87.3% and 87.2%, respectively; ß-blockers, 74.0% versus 80.9% and 81.4%; and statins, 80.6% versus 85.9% and 85.2%). Flexible parametric survival modelling indicated that patients in class 1 and class 2 had a 2.4-fold (95% CI 2.3-2.5) and 1.5-fold (95% CI 1.4-1.5) increased risk of death and a loss in life expectancy of 2.89 and 1.52 years, respectively, compared with those in class 3 over the 8.4-year follow-up period. The study was limited to all-cause mortality due to the lack of available cause-specific mortality data. However, we isolated the disease-specific association with mortality by providing the loss in life expectancy following AMI according to multimorbidity phenotype cluster compared with the general age-, sex-, and year-matched population. CONCLUSIONS: Multimorbidity among patients with AMI was common, and conferred an accumulative increased risk of death. Three multimorbidity phenotype clusters that were significantly associated with loss in life expectancy were identified and should be a concomitant treatment target to improve cardiovascular outcomes. TRIAL REGISTRATION: ClinicalTrials.gov NCT03037255.

Longitudinal assessment of right ventricular structure and function by cardiovascular magnetic resonance in breast cancer patients treated with trastuzumab: a prospective observational study.

BACKGROUND: There are limited data on the effects of trastuzumab on the right ventricle (RV). Therefore, we sought to evaluate the temporal changes in right ventricular (RV) structure and function as measured by cardiovascular magnetic resonance (CMR), and their relationship with left ventricular (LV) structure and function in breast cancer patients treated with trastuzumab. METHODS: Prospective, longitudinal, observational study involving 41 women with HER2+ breast cancer who underwent serial CMR at baseline, 6, 12, and 18 months after initiation of trastuzumab. A single blinded observer measured RV parameters on de-identified CMRs in a random order. Linear mixed models were used to investigate temporal changes in RV parameters. RESULTS: Of the 41 women (age 52 ± 11 years), only one patient experienced trastuzumab-induced cardiotoxicity. Compared to baseline, there were small but significant increases in the RV end-diastolic volume at 6 months (p = 0.002) and RV end-systolic volume at 6 and 12 months (p < 0.001 for both), but not at 18 months (p = 0.82 and 0.13 respectively). RV ejection fraction (RVEF), when compared to baseline (58.3%, 95% CI 57.1-59.5%), showed corresponding decreases at 6 months (53.9%, 95% CI 52.5-55.4%, p < 0.001) and 12 months (55%, 95% CI 53.8-56.2%, p < 0.001) that recovered at 18 months (56.6%, 95% CI 55.1-58.0%, p = 0.08). Although the temporal pattern of changes in LVEF and RVEF were similar, there was no significant correlation between RVEF and LVEF at baseline (r = 0.29, p = 0.07) or between their changes at 6 months (r = 0.24, p = 0.17). CONCLUSION: In patients receiving trastuzumab without overt cardiotoxicity, there is a subtle but significant deleterious effect on RV structure and function that recover at 18 months, which can be detected by CMR. Furthermore, monitoring of LVEF alone may not be sufficient in detecting early RV injury. These novel findings provide further support for CMR in monitoring early cardiotoxicity. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01022086 . Date of registration: November 27, 2009.

A cluster randomized trial of objective risk assessment versus standard care for acute coronary syndromes: Rationale and design of the Australian GRACE Risk score Intervention Study (AGRIS).

BACKGROUND: Assessing risk and weighing the potential benefits from evidence-based therapies are essential in the clinical decision making process of optimizing care and outcomes for patients presenting with acute coronary syndromes (ACS). Such practices are advocated in international clinical guidelines of ACS care. While the GRACE risk score (GRS) is a guideline advocated, well-validated risk stratification tool, its utility in improving care and outcomes remains unproven, and its application has been limited in routine clinical practice. OBJECTIVE: This study will assess the effectiveness using the GRS tool and treatment recommendations during patient assessment on improving the application of guideline-recommended therapies in ACS care. DESIGN: This study employs a PROBE (prospective cluster [hospital-level] randomized open-label, blinded endpoint) design to evaluate objective measures of hospital performance, with clinical events adjudicated by a blinded event committee. This randomized study is nested within the established CONCORDANCE registry of ACS patients, with existing methods for data collection and monitoring of care and clinical outcomes. The hospital-level intervention is the integration of the GRS into routine ACS patient assessment process. The study will assess the use of early invasive management, prescription of guideline recommended pharmacology and referral to cardiac rehabilitation by hospital discharge; with the key composite clinical endpoint of cardiovascular death, new or recurrent myocardial infarction, in-hospital heart failure or cardiovascular readmission at 12 months. Health economic impacts of risk stratification implementation will also be evaluated. The study will recruit 3000 patients from 30 hospitals. SUMMARY: The AGRIS trial will establish the effect of routine objective risk stratification using the GRACE risk score on ACS care and clinical outcomes.

Relationship between time to invasive assessment and clinical outcomes of patients undergoing an early invasive strategy after fibrinolysis for ST-segment elevation myocardial infarction: a patient-level analysis of the randomized early routine invasive clinical trials.

OBJECTIVES: This study investigated the relationship between time to invasive assessment and outcomes among ST-segment elevation myocardial infarction patients randomized to early angiography after fibrinolysis. BACKGROUND: The optimal timing of coronary angiography after fibrinolysis and the association with clinical outcomes is uncertain. METHODS: Patient-level data from 6 randomized trials, with a median time to angiography <12 h after fibrinolysis, were pooled. The primary endpoint was 30-day death or reinfarction. The key secondary endpoint was in-hospital major bleeding. The relationship between fibrinolysis to angiography time and symptom onset to angiography time with outcomes was studied using 2- and 4-h intervals, respectively, and in multivariable models. RESULTS: Among 1,238 patients, the median fibrinolysis to angiography time was 165 min, and the median symptom onset to angiography time was 5.33 h. The primary and key secondary endpoints occurred in 5.7% and 4.7%, respectively. These main endpoints did not vary significantly with increasing fibrinolysis to angiography time. Early angiography (<2 h) after fibrinolysis was not associated with increased bleeding. Recurrent ischemia increased with increasing fibrinolysis to angiography time (3.7% to 7.9%, p for trend = 0.02). Thirty-day and 1-year death/reinfarction and 30-day recurrent ischemia increased significantly with increasing symptom onset to angiography time. Neither fibrinolysis to angiography time nor symptom onset to angiography time was an independent predictor of the primary endpoint. Only symptom onset to angiography time was an independent predictor of 1-year death/reinfarction (hazard ratio: 1.07, 95% confidence interval: 1.02 to 1.12, p = 0.01). CONCLUSIONS: Very early angiography (<2 h) after fibrinolysis was not associated with an increased risk of 30-day death/reinfarction or in-hospital major bleeding, and angiography within 4 h after fibrinolysis was associated with reduced 30-day recurrent ischemia. A shorter symptom onset to angiography time (<4 h) was associated with reduced 30-day and 1-year death/reinfarction and 30-day recurrent ischemia. In the current environment of regional networks of 24/7 primary percutaneous coronary intervention (PCI) centers, the clinical implication of these findings is that patients initially treated with fibrinolysis should also be promptly transferred to the nearest PCI center for immediate angiography and PCI. (Early Percutaneous Coronary Intervention [PCI] After Fibrinolysis Versus Standard Therapy in ST Segment Elevation Myocardial Infarction [STEMI] Patients; NCT01014182).

Primary prevention of cardiovascular disease: global cardiovascular risk assessment and management in clinical practice.

AIMS: For the primary prevention of cardiovascular disease, the Framingham Risk Score (FRS) is the most well-known risk prediction method. However, there are limited data regarding physicians' method of risk assessment and guideline adherence in clinical practice. METHODS AND RESULTS: In the PARADIGM (Primary cARe AuDIt of Global risk Management) study (March 2009-10), 105 primary care physicians across Canada prospectively collected data for 3015 patients (mean age 56 years, 59% men) without known cardiovascular disease, diabetes, or lipid-lowering medications at baseline. For each patient, the treating physician determined their cardiovascular risk, and reported the risk stratification method and subsequent treatment decisions. Kappa statistics assessed the agreement between the study-calculated FRS and the treating physician's reported risk assessment. The FRS was the most commonly reported risk assessment method, but was used in only 34.0% of patients. Regardless of the method used (even if the FRS was reportedly used), there was only fair agreement between the risk stratification as reported by the physician and the study-calculated FRS. Moreover, physicians recommended statin initiation in 92% of all patients that they identified as high risk; however, according to the study-calculated FRS, only 56% of the truly high-risk patients were recommended statin therapy. CONCLUSION: For the primary prevention of cardiovascular disease, these findings indicate a need to improve risk assessment and stratification, as misclassification directly contributes to suboptimal risk factor management in real-world clinical practice. Future studies should establish the optimal risk stratification method with quality improvement strategies for its subsequent implementation. CLINICAL TRIAL REGISTRATION: http://clinicaltrials.gov/ct2/show/NCT00950703; NCT00950703.

Comparative assessment of 2-dimensional echocardiography vs cardiac magnetic resonance imaging in measuring left ventricular mass in patients with and without end-stage renal disease.

BACKGROUND: While echocardiography (ECHO)-measured left ventricular mass (LVM) predicts adverse cardiovascular events that are common in hemodialysis (HD) recipients, cardiac magnetic resonance imaging (CMR) is now considered the reference standard for determination of LVM. This study aimed to evaluate concordance between LVM measurements across ECHO and CMR among chronic HD recipients and matched controls. METHODS: A single-centre, cross-sectional study of 41 chronic HD patients and 41 matched controls with normal kidney function was performed to compare LVM measurements and left ventricular hypertrophy (LVH) designation by ECHO and CMR. RESULTS: In both groups, ECHO, compared with CMR, overestimated LVM. Bland-Altman analysis demonstrated wider agreement limits in LVM measurements by ECHO and CMR in the chronic HD group (mean difference, 60.8 g; limits -23 g to 144.6 g) than in the group with normal renal function (mean difference, 51.4 g; limits -10.5 g to 113.3 g). LVH prevalence by ECHO and CMR in the chronic HD group was 37.5% and 22.5%, respectively, while 17.5% and 12.5% had LVH by ECHO and CMR, respectively, in the normal kidney function group. Intermodality agreement in the designation of LVH was modest in the chronic HD patients (κ = 0.42, P = 0.005) but strong (κ = 0.81, P < 0.001) in the patients with preserved kidney function. Agreement was strong in assessing LVH by ECHO and CMR only in those with normal kidney function. CONCLUSIONS: Our results suggest that the limitations of LVM measurement by ECHO may be more pronounced in patients receiving HD, and provide additional support for the use of CMR in research and clinical practice when rigourous assessment of LVM is essential.

Assessment of right ventricular volumes and function using cardiovascular magnetic resonance cine imaging after atrial redirection surgery for complete transposition of the great arteries.

Cardiovascular magnetic resonance (CMR) imaging is the reference standard for measurement of right ventricular (RV) volumes and function. To date, no study has compared methods of data acquisition and analysis by CMR for adults with a systemic RV. Our objective was to evaluate RV size and function using axial and short axis views in adults post atrial switch (Mustard) surgery. A total of 34 adults (20 male, mean age at CMR 32 ± 6 years) were identified at our centre. Volumes, RV end-diastolic (EDV) and end-systolic (ESV) were measured in short axis and axial orientations by two independent experienced readers, blinded to clinical and CMR data. Intra and interobserver measurements in each view were compared using Bland-Altman plots and intraclass correlation coefficients (ICC). Although mean volumes were larger in the axial as compared with the short axis view [RVEDV 247 ± 67 vs. 233 ± 54 ml (p = 0.002) and RVESV 148 ± 54 vs. 136 ± 50 ml (p = 0.001)], mean RV ejection fractions (EF) were similar [41 ± 9 % vs. 43 ± 12 % (p = 0.13)]. Bland-Altman plots demonstrated better agreement for axial measures of RVEDV and right ventricular ejection fraction (RVEF) within and between observers. Similarly, ICC values were stronger for axial as compared with short axis volumes and function-intraobserver RVEDV 0.99 (0.98-0.99) versus 0.96 (0.92-0.98) and RVEF 0.96 (0.93-0.98) versus 0.90 (0.82-0.95); interobserver RVEDV 0.97 (0.94-0.98) versus 0.90 (0.73-0.95) and RVEF 0.85 (0.53-0.94) versus 0.82 (0.67-0.90). Axially derived measurements of RV volumes and function have better agreement and reproducibility as compared with short axis values; whereas axial volumes tend to be larger, RVEF is not significantly different between the two methods.

Potential clinical impact of cardiovascular magnetic resonance assessment of ejection fraction on eligibility for cardioverter defibrillator implantation.

BACKGROUND: For the primary prevention of sudden cardiac death, guidelines provide left ventricular ejection fraction (EF) criteria for implantable cardioverter defibrillator (ICD) placement without specifying the technique by which it should be measured. We sought to investigate the potential impact of performing cardiovascular magnetic resonance (CMR) for EF on ICD eligibility. METHODS: The study population consisted of patients being considered for ICD implantation who were referred for EF assessment by CMR. Patients who underwent CMR within 30 days of echocardiography were included. Echocardiographic EF was determined by Simpson's biplane method and CMR EF was measured by Simpson's summation of discs method. RESULTS: Fifty-two patients (age 62±15 years, 81% male) had a mean EF of 38 ± 14% by echocardiography and 35 ± 14% by CMR. CMR had greater reproducibility than echocardiography for both intra-observer (ICC, 0.98 vs 0.94) and inter-observer comparisons (ICC 0.99 vs 0.93). The limits of agreement comparing CMR and echocardiographic EF were - 16 to +10 percentage points. CMR resulted in 11 of 52 (21%) and 5 of 52 (10%) of patients being reclassified regarding ICD eligibility at the EF thresholds of 35 and 30% respectively. Among patients with an echocardiographic EF of between 25 and 40%, 9 of 22 (41%) were reclassified by CMR at either the 35 or 30% threshold. Echocardiography identified only 1 of the 6 patients with left ventricular thrombus noted incidentally on CMR. CONCLUSIONS: CMR resulted in 21% of patients being reclassified regarding ICD eligibility when strict EF criteria were used. In addition, CMR detected unexpected left ventricular thrombus in almost 10% of patients. Our findings suggest that the use of CMR for EF assessment may have a substantial impact on management in patients being considered for ICD implantation.

Patient age, ethnicity, medical history, and risk factor profile, but not drug insurance coverage, predict successful attainment of glycemic targets: Time 2 Do More Quality Enhancement Research Initiative (T2DM QUERI).

OBJECTIVE: To identify factors in patients with type 2 diabetes and A1C >7.0% associated with attainment of A1C ≤ 7.0%. RESEARCH DESIGN AND METHODS: We used a prospective registry of 5,280 Canadian patients in primary care settings enrolled in a 12-month glycemic pharmacotherapy optimization strategy based on national guidelines. RESULTS: At close out, median A1C was 7.1% (vs. 7.8% at baseline) with 48% of subjects achieving A1C ≤ 7.0% (P < 0.0001). Older patients of Asian or black origin, those with longer diabetes duration, those with lower baseline A1C, BMI, LDL cholesterol, and blood pressure, and those on angiotensin receptor blockers and a lower number of antihyperglycemic agents, were more likely to achieve A1C ≤ 7.0% at some point during the study (all P < 0.0235). Access to private versus public drug coverage did not impact glycemic target realization. CONCLUSIONS: Patient demography, cardiometabolic health, and ongoing pharmacotherapy, but not access to private drug insurance coverage, contribute to the care gap in type 2 diabetes.

Bleeding and outcome in acute coronary syndrome: insights from continuous electrocardiogram monitoring in the Integrilin and Enoxaparin Randomized Assessment of Acute Coronary Syndrome Treatment (INTERACT) Trial.

BACKGROUND: Bleeding is associated with adverse outcome in acute coronary syndromes. However, the precise pathophysiologic mechanisms have not been elucidated. We sought to determine the relationship between bleeding and myocardial ischemia detected by concurrent continuous electrocardiogram (ECG) monitoring and their independent long-term prognostic significance. METHODS: The INTERACT trial was a randomized controlled trial of enoxaparin versus unfractionated heparin in patients with high-risk non-ST-elevation acute coronary syndromes. Continuous ECG monitoring, performed after enrollment up to 96 hours, was analyzed by an automated algorithm and reviewed by a blinded cardiologist. We centrally adjudicated all bleeding and clinical events in a blinded fashion and calculated the Global Registry of Acute Coronary Events risk score (a validated predictor of mortality) for each patient. RESULTS: Of the 746 patients enrolled, 34 (4.6%) developed major bleeding within 96 hours. After a median follow-up of 2.4 years, patients with bleeding had a higher risk of death (28.4% vs 7.3%, P < .001) and death/myocardial infarction (38.0% vs 12.9%, P < .001) compared with those without bleeding. Overall, 619 patients survived the first 96 hours with complete data on continuous ECG monitoring. Bleeding was associated with the simultaneous presence of ST-segment shifts on continuous ECG monitoring (P = .03). After adjusting for Global Registry of Acute Coronary Events risk score and myocardial ischemia detected by continuous ECG monitoring, major bleeding remained an independent predictor of death (adjusted hazard ratio = 3.48, 95% confidence interval 1.51-8.03, P = .003) and death/myocardial infarction (adjusted hazard ratio = 2.85, 95% confidence interval 1.40-5.78, P = .004). CONCLUSIONS: Bleeding is a powerful independent predictor of poor long-term outcome, even after adjusting for other associated prognostic factors such as advanced age and renal dysfunction. Although bleeding is associated with concurrent myocardial ischemia, its adverse prognostic impact may be mediated by complex pathophysiologic mechanisms rather than myocardial ischemia alone. Our findings suggest that future investigations should focus on other biologically plausible mechanisms.

Management patterns in relation to risk stratification among patients with non-ST elevation acute coronary syndromes.

BACKGROUND: Randomized clinical trials have established the efficacy of an early invasive management strategy for high-risk non-ST elevation acute coronary syndromes (ACSs). We examined the use of in-hospital cardiac catheterization and medications in relation to risk across the broad spectrum of non-ST elevation ACSs. METHODS: We evaluated 4414 patients with non-ST elevation ACSs in the prospective, multicenter, Canadian ACS 1 (September 1, 1999-June 30, 2001) and ACS 2 (October 1, 2002-December 31, 2003) Registries. Patients were stratified into low-, intermediate-, and high-risk groups based on tertiles of the calculated Global Registry of Acute Coronary Events risk score (a validated predictor of in-hospital mortality). RESULTS: Although in-hospital mortality rates were similar, the in-hospital use of cardiac catheterization increased significantly over time (38.8% in the ACS 1 Registry vs 63.5% in the ACS 2 Registry; P<.001). The rates of cardiac catheterization in the low-, intermediate-, and high-risk groups were 48.0%, 41.1%, and 27.3% in the ACS 1 Registry, and 73.8%, 66.9%, and 49.7% in the ACS 2 Registry, respectively (P<.001 for trend for both). After adjusting for other confounders, intermediate-risk (adjusted odds ratio, 0.75; 95% confidence interval, 0.63-0.90; P<.001) and high-risk (adjusted odds ratio, 0.35; 95% confidence interval, 0.28-0.45; P<.001) patients remained less likely to undergo cardiac catheterization compared with low-risk patients. Furthermore, there existed a similar inverse relationship between risk and the use of in-hospital revascularization and medications. CONCLUSIONS: Despite temporal increases in the use of cardiac catheterization and revascularization in the management of non-ST elevation ACSs, evidence-based invasive and pharmacological therapies remain paradoxically targeted toward low-risk patients. Strategies to eliminate this treatment-risk paradox must be implemented to fully realize the benefits and optimize the cost-effectiveness of invasive management.