Utility of prehospital electrocardiogram interpretation in ST-segment elevation myocardial infarction utilizing computer interpretation and transmission for interventional cardiologist consultation.

OBJECTIVES: We examined the appropriateness of prehospital cardiac catheter laboratory activation (CCL-A) in ST-segment elevation myocardial infarction (STEMI) utilizing the University of Glasgow algorithm (UGA) and remote interventional cardiologist consultation. BACKGROUND: The incremental benefit of prehospital electrocardiogram (PH-ECG) transmission on the diagnostic accuracy and appropriateness of CCL-A has been examined in a small number of studies with conflicting results. METHODS: We identified consecutive PH-ECG transmissions between June 2, 2010 and October 6, 2016. Blinded adjudication of ECGs, appropriateness of CCL-A, and index diagnoses were performed using the fourth universal definition of MI. The primary outcome was the appropriate CCL-A rate. Secondary outcomes included rates of false-positive CCL-A, inappropriate CCL-A, and inappropriate CCL nonactivation. RESULTS: Among 1088 PH-ECG transmissions, there were 565 (52%) CCL-As and 523 (48%) CCL nonactivations. The appropriate CCL-A rate was 97% (550 of 565 CCL-As), of which 4.9% (n = 27) were false-positive. The inappropriate CCL-A rate was 2.7% (15 of 565 CCL-As) and the inappropriate CCL nonactivation rate was 3.6% (19 of 523 CCL nonactivations). Reasons for appropriate CCL nonactivation (n = 504) included nondiagnostic ST-segment elevation (n = 128, 25%), bundle branch block (n = 132, 26%), repolarization abnormality (n = 61, 12%), artefact (n = 72, 14%), no ischemic symptoms (n = 32, 6.3%), severe comorbidities (n = 26, 5.2%), transient ST-segment elevation (n = 20, 4.0%), and others. CONCLUSIONS: PH-ECG interpretation utilizing UGA with interventional cardiologist consultation accurately identified STEMI with low rates of inappropriate and false-positive CCL-As, whereas using UGA alone would have almost doubled CCL-As. The benefits of cardiologist consultation were identifying "masquerading" STEMI and avoiding unnecessary CCL-As.

Supporting anticoagulant treatment decision making to optimise stroke prevention in complex patients with atrial fibrillation: a cluster randomised trial.

BACKGROUND: Anticoagulation for preventing stroke in atrial fibrillation is under-utilised despite evidence supporting its use, resulting in avoidable death and disability. We aimed to evaluate an intervention to improve the uptake of anticoagulation. METHODS: We carried out a national, cluster randomised controlled trial in the Australian primary health care setting. General practitioners received an educational session, delivered via telephone by a medical peer and provided information about their patients selected either because they were not receiving anticoagulation or for whom anticoagulation was considered challenging. General practitioners were randomised to receive feedback from a medical specialist about the cases (expert decisional support) either before or after completing a post-test audit. The primary outcome was the proportion of patients reported as receiving oral anticoagulation. A secondary outcome assessed antithrombotic treatment as appropriate against guideline recommendations. RESULTS: One hundred and seventy-nine general practitioners participated in the trial, contributing information about 590 cases. At post-test, 152 general practitioners (84.9%) completed data collection on 497 cases (84.2%). A 4.6% (Adjusted Relative Risk = 1.11, 95% CI = 0.86-1.43) difference in the post-test utilization of anticoagulation between groups was not statistically significant (p = 0.42). Sixty-one percent of patients in both groups received appropriate antithrombotic management according to evidence-based guidelines at post-test (Adjusted Relative Risk = 1.0; 95% CI = 0.85 to 1.19) (p = 0.97). CONCLUSIONS: Specialist feed-back in addition to an educational session did not increase the uptake of anticoagulation in patients with AF. TRIAL REGISTRATION: ANZCTRN12611000076976 Retrospectively registered.

Assessing Coronary Microvascular Dysfunction in Ischaemic Heart Disease: Little Things Can Make a Big Difference.

The role of coronary microvascular dysfunction (CMD) in the pathogenesis of ischaemic heart disease and in determining long-term prognosis is increasingly recognised. In selected patients, a comprehensive coronary assessment including an assessment of microvascular function may help refine risk stratification and improve patient outcomes. Various non-invasive and invasive techniques have been developed to assess the coronary microcirculation. Many of these tests utilise the indicator-dilution principle to determine coronary or myocardial blood flow. However, these techniques are often limited by their variability and lack of specificity for the coronary microvasculature. Consequently, there is still paucity of data on targeted therapies for CMD and their implications on long-term clinical outcomes, particularly in the setting of non-ST elevation acute coronary syndromes. Recent technical advancements, such as the index of microcirculatory resistance, have largely overcome these limitations and are able to provide novel insights into the assessment and treatment of CMD. This review summarises the currently available techniques for the assessment of CMD and provides an overview of its clinical implications.

Left atrial function to identify patients with atrial fibrillation at high risk of stroke: new insights from a large registry.

Aims: Atrial fibrillation (AF) is an independent risk factor for ischaemic stroke. The CHA2DS2-VASc is the most widely used risk stratification model; however, echocardiographic refinement may be useful, particularly in low risk AF patients. The present study examined the association between advanced echocardiographic parameters and ischaemic stroke, independent of CHA2DS2-VASc score. Methods and results: One thousand, three hundred and sixty-one patients (mean age 65±12 years, 74% males) with first diagnosis of AF and baseline transthoracic echocardiogram were followed by chart review for the occurrence of stroke over a mean of 7.9 years. Left atrial (LA) volumes, LA reservoir strain, P-wave to A' duration on tissue Doppler imaging (PA-TDI, reflecting total atrial conduction time), and left ventricular (LV) global longitudinal strain (GLS) were evaluated in patients with and without stroke. The independent association of these echocardiographic parameters with the occurrence of ischaemic stroke was evaluated with Cox proportional hazard models. One-hundred patients (7%) developed an ischaemic stroke, representing an annualized stroke rate of 0.9%. The incident stroke rate in the year following the first diagnosis of AF was 2.6% in the entire population and higher than the remainder of the follow-up period. Left atrial reservoir (14.5% vs. 18.9%, P = 0.005) and conduit strains were reduced (10.5% vs. 13.5%, P = 0.013), and PA-TDI lengthened (166 ms vs. 141 ms, P < 0.001) in the stroke compared with non-stroke group, despite similar LV dimensions, LV ejection fraction, GLS, and LA volumes. Left atrial reservoir strain and PA-TDI were independently associated with risk of stroke in a model including CHA2DS2-VASc score, age, and anticoagulant use. Conclusion: The assessment of LA reservoir strain and PA-TDI on echocardiography after initial CHA2DS2-VASc scoring provides additional risk stratification for stroke and may be useful to guide decisions regarding anticoagulation for patients upon first diagnosis of AF.

3D Echo in Routine Clinical Practice - State of the Art in 2019.

Three-dimensional (3D) echo has been around for almost five decades. Recent advances in ultrasound, electronic and computing technologies have moved 3D echo from the research environment to everyday clinical practice. Real time 3D echo and full volume acquisition are now possible with transthoracic as well as transoesophageal probes. The main advantages of 3D echo are the infinite cut planes possible, allowing direct, en face, and anatomical views of cardiac structures, avoiding foreshortening and circumventing the geometric assumptions of the cardiac chambers inherent in any 2D echo techniques. Three-dimensional echo is still dependent on image quality, subjected to ultrasound artifacts and faces the compromise between spatial and temporal resolution. In routine clinical practice in 2019, we recommend a focussed 3D examination after a full 2D echo study. The area where 3D echo has been consistently shown to have superior accuracy and reproducibility over 2D echo is in the assessment of left ventricular (LV) volumes and ejection fraction. We recommend obtaining a full volume 3D echo data set from the apical window, from which LV volumes and LV global longitudinal strain can be measured. Further 3D examination can be performed depending on the pathologies identified on 2D examination. Three-dimensional echo is superior to 2D echo in the assessment of mitral valve pathologies and atrial septal defects. Furthermore, real time 3D transoesophageal echo is a very useful technique in guiding structural cardiac intervention, both before, during and after the procedure. While 3D echo is not the holy grail of echocardiography, it does represent a useful technique in selected areas of cardiac imaging.

Left atrial function: Correlation with left ventricular function and contractile reserve in patients with hypertension.

AIMS: Alterations in left atrial (LA) and left ventricular (LV) function have been documented in hypertensive patients. However, the correlation of LA with LV functional changes has not been established. Using normotensive controls, we examined LA functional changes in hypertensive patients by strain deformation analysis, and their relationship to LV functional changes including contractile reserve (CR). METHODS: One hundred and sixteen patients (61 men, aged 57.6 ± 9.1 years, 67 with hypertension) underwent dobutamine echocardiography. Patients with significant coronary or valvular disease, previous myocardial infarction or coronary revascularization, and diabetes were excluded. LA reservoir (Ɛs), conduit (Ɛe), and atrial contractile (Ɛa) strain were measured at rest. LV global longitudinal strain (GLS) and ejection fraction (LVEF) were measured at rest and at low-dose dobutamine. LV CR was calculated as the difference in GLS and LVEF between the low dose and their corresponding resting values. RESULTS: Hypertensive patients, compared with controls, had significantly impaired LA Ɛs (30.7 ± 3.9% vs 42.4 ± 4.9%), Ɛe (16.2 ± 4.1% vs 22.5 ± 5.5%), and Ɛa (14.5 ± 4.1% vs 19.9 ± 5.0%, all P < .001) strain. All LA phasic strain correlated with LV GLS at rest, at low-dose dobutamine, and LV CR. There was no correlation between LA strain and LVEF or LV CR assessed by LVEF. LV GLS and LAVImax were the strongest independent determinants for LA Ɛs/Ɛe and LA Ɛa, respectively. CONCLUSION: Compared to controls, hypertensive patients had impaired LA strain, which correlated with LV GLS and CR. LV GLS and LAVImax were the strongest independent determinants for LA Ɛs/Ɛe and LA Ɛa, respectively, independent of BP and LVMi.

Differential Myocardial Fibre Involvement by Strain Analysis in Patients With Aortic Stenosis.

BACKGROUND: Aortic stenosis (AS) is the most common valvular heart disease and can result in left ventricular (LV) systolic impairment. LV myocardial fibres are organised in layers: the subendocardial layer is orientated longitudinally and the subepicardial layer circumferentially. We hypothesised that there is differential involvement of myocardial fibres in patients with aortic stenosis. METHODS: We performed multi-directional, multi-layered systolic strain analysis in 70 patients (aged 72±10.7years) with varying grades of AS severity (mean gradient 32.3±20mmHg, aortic valve area 1.1±0.6cm2) and in 30 controls. Clinical, demographic and resting echocardiographic data were recorded. Left ventricular subendocardial and subepicardial systolic strains were measured in the longitudinal, radial and circumferential axes. RESULTS: Systolic subendocardial strain was significantly higher than subepicardial strain in all three axes in patients and in controls. There were significant differences in longitudinal, but not in circumferential and radial strain, or left ventricular ejection fraction (LVEF), between patient groups. Aortic valve mean gradient (MG) and valve area (AVA) correlated better with subendocardial longitudinal strain (r=0.548, p<0.001; r=-0.54, p<0.001 respectively) than with subepicardial longitudinal strain (r=0.496, p<0.001, r=-0.544, p<0.001 respectively). Correlations between circumferential and radial strain and MG or AVA were poor. CONCLUSIONS: There was differential impairment in LV systolic strain in all three cardiac axes in patients with AS. Left ventricular longitudinal strain impairment was proportional to AS severity. Subendocardial longitudinal strain correlated better with AS severity than subepicardial longitudinal strain while correlations between circumferential and radial strain and AS severity were weak.

Evaluation of Serial High Sensitivity Troponin T Levels in Individuals Without Overt Coronary Heart Disease Following Exercise Stress Testing.

BACKGROUND: Detectable levels of high sensitivity (cardiac) troponin T (HsTnT), occur in the majority of patients with stable coronary heart disease (CHD), and often in 'healthy' individuals. Extreme physical activity may lead to marked elevations in creatine kinase MB and TnT levels. However, whether HsTnT elevations occur commonly after exercise stress testing (EST), and if so, whether this has clinical significance, needs clarification. METHODS: To determine whether HsTnT levels become elevated after EST (Bruce protocol) to ≥95% of predicted maximum heart rate in presumed healthy subjects without overt CHD, we assayed HsTnT levels for ∼5h post-EST in 105 subjects (median age 37 years). RESULTS: Pre-EST HsTnT levels <5 ng/L were present in 31/32 (97%) of females and 52/74 (70%) of males. Post-EST, 13 (12%) subjects developed HsTnT levels >14 ng/L, with troponin elevation occurring at least three hours post-EST. Additionally, a detectable ≥ 50% increase in HsTnT levels (4.9→9ng/L) occurred in 28 (27%) of subjects who during EST achieved ≥ 95% of their predicted target heart rate. The median age of the subjects with HsTnT elevations to > 14ng/L post-EST was higher than those without such elevation (42 and 36 years respectively; p=0.038). At a median follow-up of 13 months no adverse events were recorded. CONCLUSION: The current study demonstrates that detectable elevations occur in HsTnT post-EST in 'healthy' subjects without overt CHD. Future studies should evaluate the clinical significance of detectable elevations in post-EST HsTnT with long-term follow-up for adverse cardiac events.

The value of serial echocardiography in risk assessment of patients with paroxysmal atrial fibrillation.

Progression from paroxysmal to persistent atrial fibrillation (AF) is associated with increased morbidity and mortality. We examined the association of left atrial (LA) remodeling by serial echocardiography, and AF progression over an extended follow-up period. Two-hundred ninety patients (mean age 61  ±  11 years, 73% male) who underwent transthoracic echocardiography performed at first presentation for non-valvular paroxysmal AF (PAF) and repeat echocardiogram 1-year later, were followed for progression to persistent AF. LA and left ventricular (LV) dimensions, volumes, LA reservoir, conduit and booster pump strains, LV global longitudinal systolic strain (GLS) assessed by 2D speckle tracking, and PA-TDI (time delay between electrical and mechanical LA activation- reflecting the extent of LA fibrosis) were compared on serial echocardiography. Sixty-nine (24%) patients developed persistent AF over a mean follow-up period of 6.3 years. At baseline, patients with subsequent persistent AF had larger LA dimensions (46 mm vs. 42 mm, p < 0.001), indexed LA volumes (41 ml/m2 vs. 34 ml/m2, p < 0.001), lower LA reservoir and conduit strain (17.6% vs. 27.6%, p < 0.001; 10.5% vs. 16.3%, p < 0.001; respectively) and longer PA-TDI (155 ms vs. 132 ms, p < 0.001) compared to the PAF group. Patients with subsequent persistent AF showed over time significant enlargement in LA volumes (from 37.7 ml/m2 to 42.4 ml/m2, p < 0.001), lengthening of PA-TDI (from 142.2 ms to 162.2 ms, p = 0.002), and decline in LA reservoir function (from 21.9% to 18.1%, p = 0.024) after adjusting for age, gender, diabetes and LV GLS. There were no changes in LA diameter, LA conduit or booster pump function. Conversely, the PAF group showed no decline in LA function. Patients who developed persistent AF had larger LA size and impaired LA function and atrial conduction times at baseline, compared to patients who remained PAF. Over the 1-year time course of serial echocardiographic evaluation, there was progression of LA remodeling in patients who subsequently developed persistent AF, but not in patients who remained in PAF.

Rationale and design of a randomized trial on the impact of aldosterone antagonism on cardiac structure and function in diabetic cardiomyopathy.

UNLABELLED: Development of a cardiomyopathy in diabetes mellitus is independent of traditional risk factors, with no clinical trials targeting specific therapeutic interventions. Myocardial fibrosis is one of the key mechanisms and aldosterone is a key mediator of myocardial fibrosis. We propose that aldosterone antagonism will improve cardiac function. We aim to evaluate the efficacy of selective aldosterone receptor antagonism with eplerenone added to optimal medical treatment in improving cardiac structure and function in diabetic cardiomyopathy. We will randomize 130 patients with type 2 diabetes mellitus, stable metabolic control and impaired left ventricular (LV) systolic or diastolic function, to either eplerenone (target dose 50mg) or matching placebo, in addition to optimal medical therapy for 12 months. The primary endpoints are changes in LV systolic and diastolic function, measured by echocardiographic 2-dimensional speckle tracking strain and strain rate and tissue Doppler imaging. The secondary endpoints include changes in echocardiographic markers and plasma biomarkers of collagen turnover; left atrial dimensions and function, incidence of atrial fibrillation and changes in exercise capacity and dyspnea score. The present study will assess whether specific aldosterone antagonism with eplerenone in addition to standard therapy will prevent progression or reverse cardiac dysfunction in diabetic cardiomyopathy using sensitive, robust and quantifiable echocardiographic measures that allow early detection of change. The study may offer a new direction in the management of this condition. TRIAL REGISTRATION: ACTRN12610001063000.

Early Effects of Ticagrelor Versus Clopidogrel on Peripheral Endothelial Function After Non-ST-Elevation Acute Coronary Syndrome and Assessment of Its Relationship With Coronary Microvascular Function.

Peripheral endothelial dysfunction is an independent predictor of adverse long-term prognosis after acute coronary syndrome. Data are lacking on the effects of oral P2Y12-inhibitors on peripheral endothelial function in non-ST-elevation acute coronary syndrome (NSTEACS). Furthermore, the relation between peripheral endothelial function and invasive indexes of coronary microvascular function in NSTEACS is unclear. Between March 2018 and July 2020, hospitalized patients with NSTEACS were randomized (1:1) to ticagrelor or clopidogrel. Peripheral endothelial function was assessed with brachial artery flow-mediated vasodilation (FMD). Invasive indexes of coronary microvascular function were obtained using an intracoronary pressure-temperature sensor-tipped wire. In 70 patients included, mean age was 58.6 years, 78.6% (n = 55) were male and 20% (n = 14) had diabetes mellitus. Compared with clopidogrel, ticagrelor significantly improved FMD (14.2 ± 5.4% vs 8.9 ± 5.3%, p <0.001) after a median treatment time of 41.2 hours. The FMD was significantly correlated with the index of microcirculatory resistance (IMR) measured in the infarct-related artery (r = -0.38, p = 0.001), with a stronger correlation found in those who did not have percutaneous coronary intervention (r = -0.52, p = 0.03). Using receiver operating characteristic curve analysis, an FMD of 8.2% identified an IMR of >34 as the threshold, with 77.6% sensitivity and 52.4% specificity. In patients who did not have a percutaneous coronary intervention, an FMD of 11.49% identified an IMR of >34 with 84.6% sensitivity and 80% specificity. In conclusion, ticagrelor significantly improved peripheral endothelial function compared with clopidogrel in patients with NSTEACS. There was a significant correlation between brachial artery FMD and IMR of the infarct-related artery.

Influence of left ventricular geometry and function on aortic annular dimensions as assessed with multi-detector row computed tomography: implications for transcatheter aortic valve implantation.

AIMS: Evaluate changes in aortic annular dimensions in relation to severe aortic stenosis (AS) and left ventricular (LV) dysfunction. METHODS AND RESULTS: Mean aortic annular diameters and geometries were compared between 90 severe AS patients and 111 controls by multi-detector row computed tomography (MDCT). All severe AS patients were also dichotomized into two groups based on the presence of preserved (≥ 50%) or impaired (<50%) LV ejection fraction (EF). The influence of LV geometry and function on changes in aortic annular dimensions was examined. Patients with severe AS had similar aortic annular dimensions and geometries compared with controls even after correcting for baseline differences in age and body surface area (BSA). However, severe AS patients with LV dysfunction (LVEF <50%) had significantly larger mean aortic annular diameter (26.4 ± 1.9 vs. 24.5 ± 2.1 mm, P < 0.001) compared with patients with preserved LVEF. The presence of LV dysfunction, male gender, and larger BSA were independent determinants of a larger aortic annulus on MDCT. CONCLUSION: In severe AS patients, the presence of LV dysfunction, not the presence of severe AS, was an independent determinant of a larger aortic annular diameter.

Alterations in multidirectional myocardial functions in patients with aortic stenosis and preserved ejection fraction: a two-dimensional speckle tracking analysis.

AIMS: To identify changes in multidirectional strain and strain rate (SR) in patients with aortic stenosis (AS). METHODS AND RESULTS: A total of 420 patients (age 66.1 ± 14.5 years, 60.7% men) with aortic sclerosis, mild, moderate, and severe AS with preserved left ventricular (LV) ejection fraction [(EF), ≥50%] were included. Multidirectional strain and SR imaging were performed by two-dimensional speckle tracking. Patients were more likely to be older (P < 0.001) and at a worse New York Heart Association functional class (P < 0.001) with increasing AS severity. There was a progressive stepwise impairment in longitudinal, circumferential, and radial strain and SR with increasing AS severity (all P < 0.001). The myocardial dysfunction appeared to start in the subendocardium with mild AS, to mid-wall dysfunction with moderate AS, and eventually transmural dysfunction with severe AS. Aortic valve area, as a measure of AS severity, was an independent determinant of multidirectional strain and SR on multiple linear regressions. CONCLUSIONS: Patients with AS have evidence of subclinical myocardial dysfunction early in the disease process despite normal LVEF. The myocardial dysfunction appeared to start in the subendocardium and progressed to transmural dysfunction with increasing AS severity. Symptomatic moderate and severe AS patients had more impaired multidirectional myocardial functions compared with asymptomatic patients.

Late Outcomes of Patients With Prehospital ST-Segment Elevation and Appropriate Cardiac Catheterization Laboratory Nonactivation.

Background Patients with suspected ST-segment-elevation myocardial infarction (STEMI) and cardiac catheterization laboratory nonactivation (CCL-NA) or cancellation have reportedly similar crude and higher adjusted risks of death compared with those with CCL activation, though reasons for these poor outcomes are not clear. We determined late clinical outcomes among patients with prehospital ECG STEMI criteria who had CCL-NA compared with those who had CCL activation. Methods and Results We identified consecutive prehospital ECG transmissions between June 2, 2010 to October 6, 2016. Diagnoses according to the Fourth Universal Definition of myocardial infarction (MI), particularly rates of myocardial injury, were adjudicated. The primary outcome was all-cause death. Secondary outcomes included cardiovascular death/MI/stroke and noncardiovascular death. To explore competing risks, cause-specific hazard ratios (HRs) were obtained. Among 1033 included ECG transmissions, there were 569 (55%) CCL activations and 464 (45%) CCL-NAs (1.8% were inappropriate CCL-NAs). In the CCL activation group, adjudicated index diagnoses included MI (n=534, 94%, of which 99.6% were STEMI and 0.4% non-STEMI), acute myocardial injury (n=15, 2.6%), and chronic myocardial injury (n=6, 1.1%). In the CCL-NA group, diagnoses included MI (n=173, 37%, of which 61% were non-STEMI and 39% STEMI), chronic myocardial injury (n=107, 23%), and acute myocardial injury (n=47, 10%). At 2 years, the risk of all-cause death was higher in patients who had CCL-NA compared with CCL activation (23% versus 7.9%, adjusted risk ratio, 1.58, 95% CI, 1.24-2.00), primarily because of an excess in noncardiovascular deaths (adjusted HR, 3.56, 95% CI, 2.07-6.13). There was no significant difference in the adjusted risk for cardiovascular death/MI/stroke between the 2 groups (HR, 1.23, 95% CI, 0.87-1.73). Conclusions CCL-NA was not primarily attributable to missed STEMI, but attributable to "masquerading" with high rates of non-STEMI and myocardial injury. These patients had worse late outcomes than patients who had CCL activation, mainly because of higher rates of noncardiovascular deaths.

Impact of Ticagrelor Versus Clopidogrel on Coronary Microvascular Function After Non-ST-Segment-Elevation Acute Coronary Syndrome.

BACKGROUND: Coronary microvascular dysfunction after acute coronary syndrome is an important predictor of long-term prognosis. Data is lacking on the effects of oral P2Y12-inhibitors on coronary microvascular function in non-ST-segment-elevation acute coronary syndrome. The aim of this study was to compare the acute effects of ticagrelor versus clopidogrel pretreatment on coronary microvascular function in non-ST-segment-elevation acute coronary syndrome patients. METHODS: Hospitalized non-ST-segment-elevation acute coronary syndrome patients were randomized (1:1) to ticagrelor or clopidogrel. The index of microcirculatory resistance, coronary flow reserve, and resistive reserve ratio were obtained using an intracoronary pressure-temperature sensor-tipped wire. RESULTS: In total, 128 patients were randomized between March 2018 and July 2020. Mean age 59.2±11.8 years, 84% were male, mean Global Registry of Acute Coronary Events score was 93.7±24.5. Intracoronary physiological measurements were obtained in 118 patients (60 ticagrelor, 58 clopidogrel). In the infarct-related artery, the ticagrelor group had lower baseline index of microcirculatory resistance (22.0 [13.0-34.9] versus 27.7 [19.3-29.8]; P=0.02) and higher baseline resistive reserve ratio (3.0 [2.3-4.4] versus 2.4 [1.7-3.4]; P=0.01) compared with the clopidogrel group. A total of 88 patients underwent percutaneous coronary intervention (PCI; 45 ticagrelor, 43 clopidogrel). The ticagrelor group had lower post-PCI index of microcirculatory resistance (22.0 [15.0-29.0] versus 27.0 [18.5-47.5]; P=0.02) and higher post-PCI resistive reserve ratio (3.0 [1.8-3.8] versus 1.8 [1.5-3.4]; P=0.006) compared with the clopidogrel group. The coronary flow reserve was not significantly different between the 2 groups at baseline or post-PCI. No between-group differences were seen in any of the indices in the non-infarct-related artery. CONCLUSIONS: In non-ST-segment-elevation acute coronary syndrome patients, ticagrelor significantly improved coronary microvascular function before and after PCI compared with clopidogrel. REGISTRATION: URL: https://www.anzctr.org.au; Unique identifier: ACTRN12618001610224.

Myocardial steatosis and biventricular strain and strain rate imaging in patients with type 2 diabetes mellitus.

BACKGROUND: Magnetic resonance spectroscopy can quantify myocardial triglyceride content in type 2 diabetic patients. Its relation to alterations in left (LV) and right (RV) ventricular myocardial functions is unknown. METHODS AND RESULTS: A total of 42 men with type 2 diabetes mellitus were recruited. Exclusion criteria included hemoglobin A(1c) >8.5, known cardiovascular disease, diabetes-related complications, or blood pressure >150/85 mm Hg. Myocardial ischemia was excluded by a negative dobutamine stress test. LV and RV volumes and ejection fraction were quantified by magnetic resonance imaging. LV global longitudinal and RV free wall longitudinal strain, systolic strain rate, and diastolic strain rate were quantified by echocardiographic speckle tracking analyses. Myocardial triglyceride content was quantified by magnetic resonance spectroscopy and dichotomized on the basis of the median value of 0.76. The median age was 59 years (25th and 75th percentiles, 54 and 62 years). Median diabetes diagnosis duration was 4 years, and median glycohemoglobin level was 6.2 (25th and 75th percentiles, 5.9 and 6.8). There were no differences in LV and RV end-diastolic and end-systolic volume indexes and ejection fraction between patients with high (≥0.76) and those with low (<0.76) myocardial triglyceride content. However, patients with high myocardial triglyceride content had greater impairment of LV and RV myocardial strain and strain rate. The myocardial triglyceride content was an independent correlate of LV and RV longitudinal strain, systolic strain rate, and diastolic strain rate. CONCLUSIONS: High myocardial triglyceride content is associated with more pronounced impairment of LV and RV functions in men with uncomplicated type 2 diabetes mellitus.

Prognostic implications of left ventricular dyssynchrony early after non-ST elevation myocardial infarction without congestive heart failure.

AIMS: To determine independent predictors of left ventricular (LV) dyssynchrony after non-ST elevation myocardial infarction (NSTEMI) and prognostic value of combining dyssynchrony parameters for long-term LV dysfunction. METHODS AND RESULTS: Left ventricular dyssynchrony assessments were performed in 100 NSTEMI patients followed-up for 1 year using a composite dyssynchrony score. Early LV dyssynchrony was independently predicted by the presence of significant proximal left circumflex artery (LCx) stenosis and global systolic dysfunction. Left ventricular end-diastolic volume index decreased with time and was independently determined by a lower number of diseased vessels and the absence of early dyssynchrony. Left ventricular end-systolic volume index decreased with time and was independently determined by the absence of early dyssynchrony, lower number of diseased vessels, and revascularization. Left ventricular ejection fraction increased with time and was independently determined by the absence of early dyssynchrony, lower number of diseased vessels, and revascularization. The composite dyssynchrony score was an independent determinant of a persistently dilated LV and low LVEF at follow-up. CONCLUSION: After NSTEMI, proximal LCx stenosis and impaired LV function independently predicted LV dyssynchrony. The composite dyssynchrony score had prognostic value and identified patients with persistently dilated and impaired LV on follow-up.

An Unexpected Cause of Heart Failure in a Young Woman With Treated Lymphoma.

Arteriovenous fistula is a rare complication of lumbar surgery that may cause high-output cardiac failure. We describe the case of a patient with treated lymphoma and recent spinal surgery who presented with heart failure. Logical deduction from clinical and imaging findings helped us arrive at this unusual diagnosis. (Level of Difficulty: Intermediate.).

Impact of Targeted Therapies for Coronary Microvascular Dysfunction as Assessed by the Index of Microcirculatory Resistance.

Coronary microvascular dysfunction (CMD) has emerged as an important therapeutic target in the contemporary management of ischemic heart disease. However, due to a lack of a reliable traditional "gold standard" test for CMD, optimal treatment remains undefined. The index of microcirculatory resistance (IMR) is an intra-coronary wire-based technique that provides a more reliable and quantitative assessment of CMD and has been increasingly used as a preferred endpoint for evaluating CMD treatment strategies in recent studies. IMR can help diagnose CMD in angina patients with non-obstructive epicardial coronary disease, predict peri-procedural myocardial infarction in stable patients undergoing coronary stenting, and predict long-term prognosis after acute myocardial infarction. Studies of IMR in the setting of non-ST-elevation acute coronary syndromes are still lacking. This review critically appraises the current published literature evaluating targeted therapies for CMD using IMR as the assessment tool and provides insights into evidence gaps in this important field. The index of microcirculatory resistance has rapidly evolved from a research tool to being the new "gold standard" test for evaluating coronary microvascular dysfunction.