Omega-3 fatty acids and cardiovascular prevention: is the jury still out?

The cardiovascular benefits of omega-3 polyunsaturated fatty acids (O3FA) remain a point of confusion in clinical medicine. Recently two large, randomised trials were published with discordant findings regarding the overall benefits of omega-3 supplementation, resulting in unnecessary confusion and therapeutic nihilism. Epidemiological studies clearly show high intake of fish and measured O3FA (mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) in tissues are inversely associated with cardiovascular events and total mortality. These fatty acids are 'essential' and depend almost entirely on intake with very little production from within the body. The efficacy of supplementation depends on background tissue levels, in contradistinction to drug therapy. Insufficient dosing of omega-3 supplementation using less than 1 g/day and lack of titration to target by failing to measure O3FA levels in the blood may explain these conflicting trial outcomes. We review the current evidence regarding O3FA supplementation and cardiovascular outcomes, describe possible reasons for the discrepant results in the literature including recent controversial data around the mineral oil comparator used in REDUCE-IT and discuss the potential use of the omega-3 index to guide management and optimise supplementation in those at greatest risk.

Stress Perfusion Cardiac Magnetic Resonance vs SPECT Imaging for Detection of Coronary Artery Disease.

BACKGROUND: GadaCAD2 was 1 of 2 international, multicenter, prospective, Phase 3 clinical trials that led to U.S. Food and Drug Administration approval of gadobutrol to assess myocardial perfusion and late gadolinium enhancement (LGE) in adults with known or suspected coronary artery disease (CAD). OBJECTIVES: A prespecified secondary objective was to determine if stress perfusion cardiovascular magnetic resonance (CMR) was noninferior to single-photon emission computed tomography (SPECT) for detecting significant CAD and for excluding significant CAD. METHODS: Participants with known or suspected CAD underwent a research rest and stress perfusion CMR that was compared with a gated SPECT performed using standard clinical protocols. For CMR, adenosine or regadenoson served as vasodilators. The total dose of gadobutrol was 0.1 mmol/kg body weight. The standard of reference was a 70% stenosis defined by quantitative coronary angiography (QCA). A negative coronary computed tomography angiography could exclude CAD. Analysis was per patient. CMR, SPECT, and QCA were evaluated by independent central core lab readers blinded to clinical information. RESULTS: Participants were predominantly male (61.4% male; mean age 58.9 ± 10.2 years) and were recruited from the United States (75.0%), Australia (14.7%), Singapore (5.7%), and Canada (4.6%). The prevalence of significant CAD was 24.5% (n = 72 of 294). Stress perfusion CMR was statistically superior to gated SPECT for specificity (P = 0.002), area under the receiver operating characteristic curve (P < 0.001), accuracy (P = 0.003), positive predictive value (P < 0.001), and negative predictive value (P = 0.041). The sensitivity of CMR for a 70% QCA stenosis was noninferior and nonsuperior to gated SPECT. CONCLUSIONS: Vasodilator stress perfusion CMR, as performed with gadobutrol 0.1 mmol/kg body weight, had superior diagnostic accuracy for diagnosis and exclusion of significant CAD vs gated SPECT.

Cardiovascular Disease Implementation and Policy Priorities for Australia: Recommendations From an Australian Stakeholder Roundtable.

The Australian Cardiovascular Alliance (ACvA), the Cardiac Society of Australia and New Zealand (CSANZ) and the National Heart Foundation of Australia (NHFA) recently joined forces to bring the cardiovascular and stroke community together to convene and document a national discussion and propose a national CVD Implementation and Policy agenda and action plan. This includes prevention and screening, acute care and secondary prevention.

Evaluation of Image Quality for High Heart Rates for Coronary Computed Tomographic Angiography with Advancement in CT Technology: The CONVERGE Registry.

OBJECTIVE: This study aims to evaluate image quality in patients with heart rates above or equal to 70 beats per minute (bpm), performed on a 16 cm scanner (256-slice General Electric Revolution) in comparison to a CT scanner with only 4 cm of coverage (64 slice Volume CT). BACKGROUND: Recent advancements in image acquisition, such as whole-heart coverage in a single rotation and post-processing methods in coronary computed tomographic angiography (CCTA), include motion-correction algorithms, such as SnapShot Freeze (SSF), which improve temporal resolution and allow for the assessment of coronary artery disease (CAD) with lower motion scores and better image qualities. Studies from the comprehensive evaluation of high temporal- and spatial-resolution cardiac CT using a wide coverage system (CONVERGE) registry (a multicenter registry at four centers) have shown the 16 cm CT scanner having a better image quality in comparison to the 4 cm scanner. However, these studies failed to include patients with undesirable or high heart rates due to well-documented poor image acquisition on prior generations of CCTA scanners. METHODS: A prospective, observational, multicenter cohort study comparing image quality, quantitively and qualitatively, on scans performed on a 16 cm CCTA in comparison to a cohort of images captured on a 4 cm CCTA at four centers. Participants were recruited based on broad inclusion criteria, and each patient in the 16 cm CCTA arm of the study received a CCTA scan using a 256-slice, whole-heart, single-beat scanner. These patients were then matched by age, gender, and heart rate to patients who underwent CCTA scans on a 4 cm CT scanner. Image quality was graded based on the signal-to-noise ratio, contrast-to-noise ratio, and on a Likert scale of 0-4: 0, very poor-4, excellent. RESULTS: 104 patients were evaluated for this study. The mean heart rate was 75 ± 7 in the 4 cm scanner and 75 ± 7 in the 16 cm one (p = 0.426). The signal-to-noise and contrast-to-noise ratios were higher in the 16 cm scanner (p = 0.0001). In addition, more scans were evaluated as having an excellent quality on the 16 cm scanner than on the 4 cm scanner (p < 0.0001) based on a 4-point Likert scale. CONCLUSIONS: The 16 cm scanner has a superior image quality for fast heart rates compared to the 4 cm scanner. This study shows that there is a significantly higher frequency of excellent and good studies showing better contrast-to-noise and signal-to-noise ratios with the 16 cm scanner compared to the 4 cm scanner.

Pre-stenting residual thrombotic volume assessed by dual quantitative coronary angiography predicts microvascular obstruction in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: Microvascular obstruction (MVO) is a frequent occurrence after primary percutaneous coronary intervention (pPCI), and is associated with adverse left ventricular remodeling and worse clinical outcome. Distal embolization of thrombotic material is one of the most important underlying mechanisms. The aim of this study was to investigate the relation between the thrombotic volume evaluated by dual quantitative coronary angiography (QCA) prior to stenting and the occurrence of MVO as assessed by cardiac magnetic resonance (CMR). METHODS: Forty-eight patients with ST-segment elevation myocardial infarction (STEMI) undergoing pPCI and receiving CMR within 7 days from admission were included. Pre-stenting residual thrombus volume at the site of the culprit lesion was measured by applying automated edge detection and video-assisted densitometry techniques (i.e., dual-QCA), and patients were categorized into tertiles of thrombus volume. The presence of delayed-enhancement MVO, as well as its extent (MVO mass), were assessed by CMR. RESULTS: Pre-stenting dual-QCA thrombus volume was significantly greater in patients with MVO than in those without (5.85 mm3 [2.05-16.71] vs. 1.88 mm3 [1.03-6.92], P=0.009). Patients in the highest tertile showed greater MVO mass compared to those in the mid and lowest tertiles (113.3 gr [0.0-203.8] vs. 58.5 g [0.00-144.4] vs. 0.0 g [0.0-60.225], respectively; P=0.031). The best cut-off value of dual-QCA thrombus volume for prediction of MVO was 2.07 mm3 (AUC: 0.720). The addition of dual-QCA thrombus volume to the traditional angiographic indices of no-reflow enhanced the prediction of MVO by CMR (R=0.752). CONCLUSIONS: Pre-stenting dual-QCA thrombus volume is associated with the presence and extent of MVO detected by CMR in patients with STEMI. This methodology may aid the identification of patients at higher risk of MVO and guide adoption of preventive strategies.

Contemporary Chest Pain Evaluation: The Australian Case for Cardiac CT.

Computed tomography coronary angiography (CTCA) is a non-invasive diagnostic modality that provides a comprehensive anatomical assessment of the coronary arteries and coronary atherosclerosis, including plaque burden, composition and morphology. The past decade has witnessed an increase in the role of CTCA for evaluating patients with both stable and acute chest pain, and recent international guidelines have provided increasing support for a first line CTCA diagnostic strategy in select patients. CTCA offers some advantages over current functional tests in the detection of obstructive and non-obstructive coronary artery disease, as well as for ruling out obstructive coronary artery disease. Recent randomised trials have also shown that CTCA improves prognostication and guides the use of guideline-directed preventive therapies, leading to improved clinical outcomes. CTCA technology advances such as fractional flow reserve, plaque quantification and perivascular fat inflammation potentially allow for more personalised risk assessment and targeted therapies. Further studies evaluating demand, supply, and cost-effectiveness of CTCA for evaluating chest pain are required in Australia. This discussion paper revisits the evidence supporting the use of CTCA, provides an overview of its implications and limitations, and considers its potential role for chest pain evaluation pathways in Australia.

Australian Atherosclerosis Society Position Statement on Lipoprotein(a): Clinical and Implementation Recommendations.

This position statement provides guidance to cardiologists and related specialists on the management of adult patients with elevated lipoprotein(a) [Lp(a)]. Elevated Lp(a) is an independent and causal risk factor for atherosclerotic cardiovascular disease (ASCVD) and calcific aortic valve disease (CAVD). While circulating Lp(a) levels are largely determined by ancestry, they are also influenced by ethnicity, hormones, renal function, and acute inflammatory events, such that measurement should be done after accounting for these factors. Further, circulating Lp(a) concentrations should be estimated using an apo(a)-isoform independent assay that employs appropriate calibrators and reports the results in molar units (nmol/L). Selective screening strategies of high-risk patients are recommended, but universal screening of the population is currently not advised. Testing for elevated Lp(a) is recommended in all patients with premature ASCVD and those considered to be at intermediate-to-high risk of ASCVD. Elevated Lp(a) should be employed to assess and stratify risk and to enable a decision on initiation or intensification of preventative treatments, such as cholesterol lowering therapy. In adult patients with elevated Lp(a) at intermediate-to-high risk of ASCVD, absolute risk should be reduced by addressing all modifiable behavioural, lifestyle, psychosocial and clinical risk factors, including maximising cholesterol-lowering with statin and ezetimibe and, where appropriate, PCSK9 inhibitors. Apheresis should be considered in patients with progressive ASCVD. New ribonucleic acid (RNA)-based therapies which directly lower Lp(a) are undergoing clinical trials.

2022 use of coronary computed tomographic angiography for patients presenting with acute chest pain to the emergency department: An expert consensus document of the Society of cardiovascular computed tomography (SCCT): Endorsed by the American College of Radiology (ACR) and North American Society for cardiovascular Imaging (NASCI).

Coronary computed tomography angiography (CTA) improves the quality of care for patients presenting with acute chest pain (ACP) to the emergency department (ED), particularly in patients with low to intermediate likelihood of acute coronary syndrome (ACS). The Society of Cardiovascular Computed Tomography Guidelines Committee was formed to develop recommendations for acquiring, interpreting, and reporting of coronary CTA to ensure appropriate, safe, and efficient use of this modality. Because of the increasing use of coronary CTA testing for the evaluation of ACP patients, the Committee has been charged with the development of the present document to assist physicians and technologists. These recommendations were produced as an educational tool for practitioners evaluating acute chest pain patients in the ED, in the interest of developing systematic standards of practice for coronary CTA based on the best available data or broad expert consensus. Due to the highly variable nature of medical care, approaches to patient selection, preparation, protocol selection, interpretation or reporting that differs from these guidelines may represent an appropriate variation based on a legitimate assessment of an individual patient's needs.

Stress perfusion cardiovascular magnetic resonance imaging: a guide for the general cardiologist.

Stress cardiovascular magnetic resonance (CMR) is an emerging non-invasive imaging technique for the assessment of known or suspected ischaemic heart disease (IHD). Stress CMR provides information on myocardial perfusion, wall motion, ventricular dimensions and volumes, as well as late gadolinium enhancement (LGE) scar imaging in a single test without ionising radiation. Data from numerous multicentre randomised studies show high diagnostic and prognostic utility, its efficacy as a gatekeeper to invasive coronary angiography and use for guiding coronary revascularisation decisions. Stress CMR is cost-effective across multiple healthcare settings, yet its uptake and usage varies worldwide and is an underutilised technology. New developments include rapid acquisition protocols, automated quantification of perfusion and myocardial blood flow, and artificial intelligence-aided automated analysis and reporting. Stress CMR is becoming more accessible and standardised around the globe and is ready for 'prime time' use in the non-invasive assessment of patients with suspected IHD.

Noninvasive Plaque Imaging to Accelerate Coronary Artery Disease Drug Development.

Coronary artery disease (CAD) remains the leading cause of adult mortality globally. Targeting known modifiable risk factors has had substantial benefit, but there remains a need for new approaches. Improvements in invasive and noninvasive imaging techniques have enabled an increasing recognition of distinct quantitative phenotypes of coronary atherosclerosis that are prognostically relevant. There are marked differences in plaque phenotype, from the high-risk, lipid-rich, thin-capped atheroma to the low-risk, quiescent, eccentric, nonobstructive calcified plaque. Such distinct phenotypes reflect different pathophysiologic pathways and are associated with different risks for acute ischemic events. Noninvasive coronary imaging techniques, such as computed tomography, positron emission tomography, and coronary magnetic resonance imaging, have major potential to accelerate cardiovascular drug development, which has been affected by the high costs and protracted timelines of cardiovascular outcome trials. This may be achieved through enrichment of high-risk phenotypes with higher event rates or as primary end points of drug efficacy, at least in phase 2 trials, in a manner historically performed through intravascular coronary imaging studies. Herein, we provide a comprehensive review of the current technology available and its application in clinical trials, including implications for sample size requirements, as well as potential limitations. In its effort to accelerate drug development, the US Food and Drug Administration has approved surrogate end points for 120 conditions, but not for CAD. There are robust data showing the beneficial effects of drugs, including statins, on CAD progression and plaque stabilization in a manner that correlates with established clinical end points of mortality and major adverse cardiovascular events. This, together with a clear mechanistic rationale for using imaging as a surrogate CAD end point, makes it timely for CAD imaging end points to be considered. We discuss the importance of global consensus on these imaging end points and protocols and partnership with regulatory bodies to build a more informed, sustainable staged pathway for novel therapies.

Type-2 Diabetes and the Clinical Importance of Exaggerated Exercise Blood Pressure.

BACKGROUND: Exaggerated exercise blood pressure (EEBP) during clinical exercise testing is associated with poor blood pressure (BP) control and cardiovascular disease (CVD). Type-2 diabetes (T2DM) is thought to be associated with increased prevalence of EEBP, but this has never been definitively determined and was the aim of this study. METHODS: Clinical exercise test records were analyzed from 13 268 people (aged 53±13 years, 59% male) who completed the Bruce treadmill protocol (stages 1-4, and peak) at 4 Australian public hospitals. Records (including BP) were linked to administrative health datasets (hospital and emergency admissions) to define clinical characteristics and classify T2DM (n=1199) versus no T2DM (n=12 069). EEBP was defined as systolic BP ≥90th percentile at each test stage. Exercise BP was regressed on T2DM history and adjusted for CVD and risk factors. RESULTS: Prevalence of EEBP (age, sex, preexercise BP, hypertension history, CVD history and aerobic capacity adjusted) was 12% to 51% greater in T2DM versus no T2DM (prevalence ratio [95% CI], stage 1, 1.12 [1.02-1.24]; stage 2, 1.51 [1.41-1.61]; stage 3, 1.25 [1.10-1.42]; peak, 1.18 [1.09-1.29]). At stages 1 to 3, 8.6% to 15.8% (4.8%-9.7% T2DM versus 3.5% to 6.1% no-T2DM) of people with 'normal' preexercise BP (<140/90 mm Hg) were identified with EEBP. Exercise systolic BP relative to aerobic capacity (stages 1-4 and peak) was higher in T2DM with adjustment for all CVD risk factors. CONCLUSIONS: People with T2DM have higher prevalence of EEBP and exercise systolic BP independent of CVD and many of its known risk factors. Clinicians supervising exercise testing should be alerted to increased likelihood of EEBP and thus poor BP control warranting follow-up care in people with T2DM.

Colchicine and Quality of Life in Patients With Acute Coronary Syndromes: Results From the COPS Randomized Trial.

BACKGROUND: Recent data suggest that colchicine may reduce cardiovascular events among patients presenting with acute coronary syndromes. This sub-study of the Australian COPS trial aimed to assess whether colchicine affects health status outcomes. METHODS: Health status was assessed at baseline and 12-months using the EuroQol-5 Dimension 5-level (EQ-5D-5L) score and the full 19-question Seattle Angina Questionnaire (SAQ). Data were available for 786 patients (388 randomized to colchicine, 398 to placebo). RESULTS: Baseline characteristics were well matched between groups; mean age was 60.1 (SD 14.8) years, and 20 % were female. Baseline health status scores were impaired, and most parameters demonstrated significant improvement from baseline to 12-months (EQ-5D-5L Visual Analogue Score [VAS] 69.3 to 77.7; SAQ angina frequency score 83.0 to 95.3, both p < 0.001). No significant differences in adjusted mean score change among any of the EQ-5D-5L or SAQ dimensions were observed between treatment groups in either intention-to-treat or per-protocol analysis. There were borderline interactions in EQ-5D-5L scores for those with previous MI vs not, and in SAQ scores for those with obesity vs not. In categorical analysis using observed data, patients treated with colchicine were more likely to have clinically significant improvement in physical limitation score over the period (36 % improved vs. 28 %, p < 0.05). Baseline health status scores were not associated with the primary endpoint at 12 months. CONCLUSIONS: Treatment with colchicine did not appear to affect change in measures of health status following acute coronary syndromes, but it did lead to a greater likelihood of improvement in physical limitation scores. TRIAL REGISTRATION: ACTRN, ACTRN12615000861550. Registered 18/08/2015, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368973.

Text Messages to Improve Medication Adherence and Secondary Prevention After Acute Coronary Syndrome: The TEXTMEDS Randomized Clinical Trial.

BACKGROUND: TEXTMEDS (Text Messages to Improve Medication Adherence and Secondary Prevention After Acute Coronary Syndrome) examined the effects of text message-delivered cardiac education and support on medication adherence after an acute coronary syndrome. METHODS: TEXTMEDS was a single-blind, multicenter, randomized controlled trial of patients after acute coronary syndrome. The control group received usual care (secondary prevention as determined by the treating clinician); the intervention group also received multiple motivational and supportive weekly text messages on medications and healthy lifestyle with the opportunity for 2-way communication (text or telephone). The primary end point of self-reported medication adherence was the percentage of patients who were adherent, defined as >80% adherence to each of up to 5 indicated cardioprotective medications, at both 6 and 12 months. RESULTS: A total of 1424 patients (mean age, 58 years [SD, 11]; 79% male) were randomized from 18 Australian public teaching hospitals. There was no significant difference in the primary end point of self-reported medication adherence between the intervention and control groups (relative risk, 0.93 [95% CI, 0.84-1.03]; P=0.15). There was no difference between intervention and control groups at 12 months in adherence to individual medications (aspirin, 96% vs 96%; ß-blocker, 84% vs 84%; angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, 77% vs 80%; statin, 95% vs 95%; second antiplatelet, 84% vs 84% [all P>0.05]), systolic blood pressure (130 vs 129 mm Hg; P=0.26), low-density lipoprotein cholesterol (2.0 vs 1.9 mmol/L; P=0.34), smoking (P=0.59), or exercising regularly (71% vs 68%; P=0.52). There were small differences in lifestyle risk factors in favor of intervention on body mass index <25 kg/m2 (21% vs 18%; P=0.01), eating ≥5 servings per day of vegetables (9% vs 5%; P=0.03), and eating ≥2 servings per day of fruit (44% vs 39%; P=0.01). CONCLUSIONS: A text message-based program had no effect on medical adherence but small effects on lifestyle risk factors. REGISTRATION: URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=364448; Unique identifier: ANZCTR ACTRN12613000793718.

Radiation Doses in Patients Undergoing Computed Tomographic Coronary Artery Calcium Evaluation With a 64-Slice Scanner Versus a 256-Slice Scanner.

Computed tomographic coronary artery calcium scanning enables cardiovascular risk stratification; however, exposing patients to high radiation levels is an ongoing concern. New-generation computed tomographic systems use lower radiation doses than older systems do. To quantify comparative doses of radiation exposure, we prospectively acquired images from 220 patients with use of a 64-slice GE LightSpeed VCT scanner (control group, n=110) and a 256-slice GE Revolution scanner (study group, n=110). The groups were matched for age, sex, and body mass index; statistical analysis included t tests and linear regression. The mean dose-length product was 21% lower in the study group than in the control group (60.2 ± 27 vs 75.9 ± 22.6 mGy·cm; P <0.001) and also in each body mass index subgroup. Similarly, the mean effective radiation dose was 21% lower in the study group (0.84 ± 0.38 vs 1.06 ± 0.32 mSv) and lower in each weight subgroup. After adjustment for sex, women in the study group had a lower dose-length product (50.4 ± 23.4 vs 64.7 ± 27.6 mGy·cm) than men did and received a lower effective dose (0.7 ± 0.32 vs 0.9 ± 0.38 mSv) (P=0.009). As body mass index and waist circumference increased, so did doses for both scanners. Our study group was exposed to radiation doses lower than the previously determined standard of 1 mSv, even after adjustment for body mass index and waist circumference. In 256-slice scanning for coronary artery calcium, radiation doses are now similar to those in lung cancer screening and mammography.

Impact of inter-vendor variability on evaluation of left ventricular mechanical dispersion.

PURPOSE: Left ventricular mechanical dispersion (LVMD) is a novel speckle tracking parameter for prognostic assessment of arrhythmic risk prediction. There is growing evidence to support its use in a variety of cardiomyopathic processes. There is paucity of data addressing any presence of inter-vendor discrepancies for LVMD. The aim of this study was to assess inter-vendor variability of LVMD in vendor specific software (VSS) and vendor independent software (VIS) in subjects with preserved and reduced left ventricular function. METHODS: Fifty-nine subjects (14 normal subjects and 45 subjects with cardiac disease) were recruited and 2D speckle tracking echocardiographic images were acquired on two different ultrasound machines (GE and Philips). LVMD was measured by two different VSS (EchoPac GE and QLAB Philips) and one VIS (TomTec Arena). RESULTS: There was significant bias and wide limits of agreement (LOA) in the overall cohort observed between two different VSS (17.6 ms; LOA: -29.6 to 64.8; r: .47). There was acceptable bias and narrower LOA with good agreement for LVMD between images obtained on different vendors when performed on VIS (-3.1 ms; LOA: -27.6 to 21.4; r: .75). QLAB LVMD was consistently higher than GE LVMD and TomTec LVMD in both preserved and reduced left ventricular function. LVMD measurements have high intra-vendor reproducibility with excellent inter and intra-observer agreement. CONCLUSIONS: There was acceptable bias and narrower LOA for LVMD assessment on a VIS. Inter-vendor variability exists for LVMD assessment between VSS. Serial measurements of LVMD should be performed using a single vendor for consistent and reliable results.

Global longitudinal strain as a prognostic marker in cardiac resynchronisation therapy: A systematic review.

PURPOSE: Cardiac resynchronisation therapy (CRT) has proven mortality benefits for heart failure patients with moderate to severe systolic left ventricular dysfunction and evidence of a left bundle branch block. Determining responders to this therapy can be difficult due to the presence of myocardial fibrosis and scar. Left ventricular global longitudinal strain (LV GLS) is a robust and sensitive measure of myocardial function and fibrosis that has significant prognostic value for a plethora of cardiac pathologies. Our aim was to perform a systematic review of the value of LV GLS for predicting outcomes in patients undergoing CRT. METHODS: A systematic review of the literature was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol for reporting on systematic reviews and meta-analyses. An electronic search of all English, adult publications in EMBASE, MEDLINE/PubMed and the Cochrane Database of Systematic reviews was undertaken. RESULTS: The search yielded, 9 studies that included 3,981 patients with symptomatic heart failure, undergoing CRT implantation with LV GLS utilised as a predictor of all-cause mortality, cardiovascular death, rehospitalisation, LVAD implantation/ heart transplantation or left ventricular reverse remodelling. Significant heterogeneity was observed in study outcome measures, included populations, LV-GLS cut-offs and follow-up definitions, resulting in the inability to reliably conduct a meta-analyses. Overall, pre-CRT LV GLS was found to be a predictor of outcome post CRT insertion. CONCLUSIONS: In conclusion, all studies implied that incrementally abnormal baseline LV GLS pre-CRT implantation was associated with a long term poorer outcome.

Examining the Potential for Coronary Artery Calcium (CAC) Scoring for Individuals at Low Cardiovascular Risk.

Atherosclerosis is the commonest cause of death in Australia. Cardiovascular (CV) risk calculators have an important role in preventative cardiology, although they are are strongly age-dependent and designed to identify individuals at high risk of an imminent event. The imprecision around "intermediate" or "low" risk generates therapeutic uncertainty, and a significant proportion of patients presenting with myocardial infarction come from these groups, often with no warning. This highlights a conundrum: "Low" risk does not mean "no" risk. A fresh approach may be required to address the clinical conundrum around CV preventative approaches in non-high-risk individuals. While probabilistic calculators do not measure atherosclerosis, calculation of Coronary Artery Calcium (CAC) scores by low-dose computed tomography (CT) can provide a snapshot of atherosclerotic burden. In intermediate-risk individuals, CAC is well-established as an aid to CV risk prediction. Although CAC scoring in low-risk asymptomatic people may be considered controversial, CAC has emerged as the single best predictor of CV events in asymptomatic individuals, independent of traditional risk factor calculators. Therefore, apart from the contribution of age and sex, the somewhat arbitrary distinction between "intermediate" and "low" CV risk using probabilistic calculators may need to be reconsidered. A zero CAC score has a very low future event rate and non-zero CAC scores are associated with a progressive, graded increase in risk as the CAC score rises. Here, we examine the evidence for CAC screening in low-risk individuals, and propose more widespread use of CAC using simple new model intended to enhance established CV risk prediction equations.

7-Tesla Functional Cardiovascular MR Using Vectorcardiographic Triggering-Overcoming the Magnetohydrodynamic Effect.

Objective: Ultra-high-field B0 ≥ 7 tesla (7T) cardiovascular magnetic resonance (CMR) offers increased resolution. However, electrocardiogram (ECG) gating is impacted by the magneto-hydrodynamic effect distorting the ECG trace. We explored the technical feasibility of a 7T magnetic resonance scanner using an ECG trigger learning algorithm to quantitatively assess cardiac volumes and vascular flow. Methods: 7T scans were performed on 10 healthy volunteers on a whole-body research MRI MR scanner (Siemens Healthineers, Erlangen, Germany) with 8 channel Tx/32 channels Rx cardiac coils (MRI Tools GmbH, Berlin, Germany). Vectorcardiogram ECG was performed using a learning phase outside of the magnetic field, with a trigger algorithm overcoming severe ECG signal distortions. Vectorcardiograms were quantitatively analyzed for false negative and false positive events. Cine CMR was performed after 3rd-order B0 shimming using a high-resolution breath-held ECG-retro-gated segmented spoiled gradient echo, and 2D phase contrast flow imaging. Artefacts were assessed using a semi-quantitative scale. Results: 7T CMR scans were acquired in all patients (100%) using the vectorcardiogram learning method. 3,142 R-waves were quantitatively analyzed, yielding sensitivity of 97.6% and specificity of 98.7%. Mean image quality score was 0.9, sufficient to quantitate both cardiac volumes, ejection fraction, and aortic and pulmonary blood flow. Mean left ventricular ejection fraction was 56.4%, right ventricular ejection fraction was 51.4%. Conclusion: Reliable cardiac ECG triggering is feasible in healthy volunteers at 7T utilizing a state-of-the-art three-lead trigger device despite signal distortion from the magnetohydrodynamic effect. This provides sufficient image quality for quantitative analysis. Other ultra-high-field imaging applications such as human brain functional MRI with physiologic noise correction may benefit from this method of ECG triggering.

Electrophysiologic and imaging evidence for an occult myopathic substrate in patients with idiopathic ventricular arrhythmias.

BACKGROUND: Idiopathic VA are traditionally considered benign, although occasional patients develop an ectopy-mediated cardiomyopathy (EMC). It is unclear whether patients with idiopathic VA in the absence of left ventricular (LV) dysfunction harbor a subclinical cardiomyopathy. We aim to assess for cardiomyopathic substrate in patients with idiopathic ventricular arrhythmias (VA) using imaging and electrophysiologic markers of early fibrosis. METHODS: Cardiac magnetic resonance (CMR) imaging and ventricular electroanatomic mapping was performed in 3 groups: patients undergoing ablation for idiopathic VA without (Group 1, n = 17) and with LV dysfunction (Group 2 [presumed EMC], n = 12) plus a control group undergoing ablation of supraventricular tachycardia (Group 3, n = 16). Global LV strain, T1 mapping and extended electrogram (EGM) characteristics were compared. RESULTS: Global strain was impaired in patients with presumed EMC (Group 2, p < 0.001). Native T1 times did not differ between groups, however patients in both idiopathic VA groups (Groups 1 and 2) had shorter post-contrast T1 times at 8 min compared to SVT controls (Group 3, p = 0.04). Similarly, the duration of the bipolar EGM was subtly prolonged in both Group 1 and 2 compared to Group 3 (p = 0.002). There were no between group differences in unipolar or bipolar voltage, the no. of bipolar EGM deflections or the maximal unipolar EGM dV/dt. CONCLUSION: Patients with idiopathic VAs and apparently structurally normal hearts may have subtle CMR and electrophysiologic changes similar in magnitude to that seen in frank presumed EMC, possibly suggestive of an occult cardiomyopathic process.