Effects of a culturally informed model of care for Aboriginal and Torres Strait Islander patients with acute coronary syndrome in a tertiary hospital in Australia: a pre-post, quasi-experimental, interventional study.

BACKGROUND: Aboriginal and Torres Strait Islander (Indigenous) peoples with cardiac disease in Australia have worse outcomes than non-Indigenous people with cardiac disease. We hypothesised that the implementation of a culturally informed model of care for Indigenous patients hospitalised with acute coronary syndrome (ACS) would improve their clinical outcomes. METHODS: For this pre-post, quasi-experimental, interventional study, cohorts of Indigenous patients before and after the implementation of a model of care were compared. The novel, culturally informed, multidisciplinary-team model of care was a local programme of care developed to reduce morbidity and mortality from cardiac conditions among Indigenous Australians. All index admissions in the 24-month pre-implementation period (Jan 1 2013, to Dec 31, 2014) were analysed, as were all index admissions in the 12-month post-implementation period (Oct 1, 2015, to Sept 30, 2016). Comparisons were also made with non-Indigenous cohorts in the same timeframes. Admissions were excluded if the patient did not survive to hospital discharge. The study was conducted at Princess Alexandra Hospital, a tertiary hospital in metropolitan Brisbane (QLD, Australia). Data on presentation, comorbidities, investigations, treatment, and for outcomes were manually collected from a consolidated clinical information application. Mortality data were obtained from the Queensland Registry of Births, Deaths, and Marriages. The primary outcome was a composite of death, acute myocardial infarction, unplanned revascularisation, and cardiac readmission at 90 days after index admission, assessed in all patients. FINDINGS: The Indigenous cohorts included 199 patients admitted with ACS before the model of care was implemented (85 [43%] were female and 114 [57%] were male) and 119 admitted post-implementation (62 [52%] were female and 57 [48%] were male). The non-Indigenous cohorts included 440 patients with ACS before the model of care was implemented (140 [32%] were female and 300 [68%] were male) and 467 admitted post-implementation (143 [31%] were female and 324 [69%] were male). Compared with the pre-implementation group, Indigenous patients admitted post-implementation had a significant reduction in the primary outcome (67 [34%] of 199 vs 24 [20%] of 119; hazard ratio 0·60, 95% CI 0·40-0·90; p=0·012), which was driven by a reduction in unplanned cardiac readmissions (64 [32%] of 199 vs 21 [18%] of 119; 0·55, 0·35-0·85; p=0·0060). There was no significant change in non-Indigenous patients between the pre-implementation and post-implementation timeframes in the composite endpoint at 90 days (81 [18%] of 440 vs 93 [20%] of 467; 1·08, 0·83-1·41; p=0·54). Pre-implementation, there was significantly more incidence of the primary outcome in Indigenous patients than non-Indigenous patients (p<0·0001), with no significant difference in the post-implementation period (p=0·92). INTERPRETATION: Clinical outcomes for Indigenous patients admitted to a tertiary hospital in Australia improved after implementation of a culturally informed model of care, with a reduction in the disparity in incidence of primary endpoints that existed between Indigenous and non-Indigenous patients before implementation. FUNDING: Queensland Department of Health Aboriginal and Torres Strait Islander Health Division (now First Nations Health Office).

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.

Cardiac "hypertrophy" phenotyping: differentiating aetiologies with increased left ventricular wall thickness on echocardiography.

Aims: Differentiating phenotypes of cardiac "hypertrophy" characterised by increased wall thickness on echocardiography is essential for management and prognostication. Transthoracic echocardiography is the most commonly used screening test for this purpose. We sought to identify echocardiographic markers that distinguish infiltrative and storage disorders that present with increased left ventricular (LV) wall thickness, namely, cardiac amyloidosis (CA) and Anderson-Fabry disease (AFD), from hypertensive heart disease (HHT). Methods: Patients were retrospectively recruited from Westmead Hospital, Sydney, and Princess Alexandra Hospital, Brisbane. LV structural, systolic, and diastolic function parameters, as well as global (LVGLS) and segmental longitudinal strains, were assessed. Previously reported echocardiographic parameters including relative apical sparing ratio (RAS), LV ejection fraction-to-strain ratio (EFSR), mass-to-strain ratio (MSR) and amyloidosis index (AMYLI) score (relative wall thickness × E/e') were evaluated. Results: A total of 209 patients {120 CA [58 transthyretin amyloidosis (ATTR) and 62 light-chain (AL) amyloidosis], 31 AFD and 58 HHT patients; mean age 64.1 ± 13.7 years, 75% male} comprised the study cohort. Echocardiographic measurements differed across the three groups, The LV mass index was higher in both CA {median 126.6 [interquartile range (IQR) 106.4-157.9 g/m2]} and AFD [median 134 (IQR 108.8-152.2 g/m2)] vs. HHT [median 92.7 (IQR 79.6-102.3 g/m2), p < 0.05]. LVGLS was lowest in CA [median 12.29 (IQR 10.33-15.56%)] followed by AFD [median 16.92 (IQR 14.14-18.78%)] then HHT [median 18.56 (IQR 17.51-19.97%), p < 0.05]. Diastolic function measurements including average e' and E/e' were most impaired in CA and least impaired in AFD. Indexed left atrial volume was highest in CA. EFSR and MSR differentiated secondary (CA + AFD) from HHT [receiver operating curve-area under the curve (ROC-AUC) of 0.80 and 0.91, respectively]. RAS and AMYLI score differentiated CA from AFD (ROC-AUC of 0.79 and 0.80, respectively). A linear discriminant analysis with stepwise variable selection using linear combinations of LV mass index, average e', LVGLS and basal strain correctly classified 79% of all cases. Conclusion: Simple echocardiographic parameters differentiate between different "hypertrophic" cardiac phenotypes. These have potential utility as a screening tool to guide further confirmatory testing.

Prevalence and Prognostic Implications of Moderate or Severe Mitral Regurgitation in Patients with Bicuspid Aortic Valve.

BACKGROUND: Significant (moderate or greater) mitral regurgitation (MR) could augment the hemodynamic effects of aortic valvular disease in patients with bicuspid aortic valve (BAV), imposing a greater hemodynamic burden on the left ventricle and atrium, possibly culminating in a faster onset of left ventricular dilation and/or symptoms. The aim of this study was to determine the prevalence and prognostic implications of significant MR in patients with BAV. METHODS: In this large, multicenter, international registry, a total of 2,932 patients (mean age, 48 ± 18 years; 71% men) with BAV were identified. All patients were evaluated for the presence of significant primary or secondary MR by transthoracic echocardiography and were followed up for the end points of all-cause mortality and event-free survival. RESULTS: Overall, 147 patients (5.0%) had significant primary (1.5%) or secondary (3.5%) MR. Significant MR was associated with all-cause mortality (hazard ratio [HR], 2.80; 95% CI, 1.91-4.11; P < .001) and reduced event-free survival (HR, 1.97; 95% CI, 1.58-2.46; P < .001) on univariable analysis. MR was not associated with all-cause mortality (adjusted HR, 1.33; 95% CI, 0.85-2.07; P = .21) or event-free survival (adjusted HR, 1.10; 95% CI, 0.85-1.42; P = .49) after multivariable adjustment. However, sensitivity analyses demonstrated that significant MR not due to aortic valve disease retained an independent association with mortality (adjusted HR, 1.81; 95% CI, 1.04-3.15; P = .037). Subgroup analyses demonstrated an independent association between significant MR and all-cause mortality for individuals with significant aortic regurgitation (HR, 2.037; 95% CI, 1.025-4.049; P = .042), although this association was not observed for subgroups with significant aortic stenosis or without significant aortic valve dysfunction. CONCLUSIONS: Significant MR is uncommon in patients with BAV. Following adjustment for important confounding variables, significant MR was not associated with adverse prognosis in this large study of patients with BAV, except for the patient subgroup with moderate to severe aortic regurgitation. In addition, significant MR not due to aortic valve disease demonstrated an independent association with all-cause mortality.

Long-Term Changes in Cardiac Structure and Function Following Bariatric Surgery.

BACKGROUND: Studies with short-term follow-up have demonstrated favorable effects of weight loss (WL) on the heart, but little information is available regarding long-term effects or effects of visceral fat reduction. OBJECTIVES: The purpose of this study was to evaluate the effects of long-term WL following bariatric surgery on cardiac structure, function, ventricular interaction, and body composition, including epicardial adipose thickness and abdominal visceral adipose tissue (VAT). METHODS: A total of 213 obese patients underwent echocardiography before and >180 days following bariatric surgery. Abdominal VAT area was measured by computed tomography in 52 of these patients. RESULTS: After 5.3 years (IQR: 2.9-7.9 years), body mass index (BMI) decreased by 22%, with favorable reductions in blood pressure, fasting glucose, and left ventricular (LV) remodeling in the full sample. In the subgroup of patients with abdominal computed tomography, VAT area decreased by 30%. In all subjects, epicardial adipose thickness was reduced by 14% (both P < 0.0001) in tandem with reductions in ventricular interdependence. LV and right ventricular longitudinal strain improved following WL, but left atrial (LA) strain deteriorated, while LA volume and estimated LA pressures increased. In subgroup analysis, LV wall thickness and strain correlated more strongly with VAT than BMI at baseline, and reductions in LV mass following surgery were correlated with decreases in VAT, but not BMI. CONCLUSIONS: In this observational study, weight loss following bariatric surgery was associated with epicardial fat reduction, reduced ventricular interaction, LV reverse remodeling, and improved longitudinal biventricular mechanics, but LA myopathy and hemodynamic congestion still progressed. Reduction in visceral fat was associated with favorable cardiac effects, suggesting this might be a key target of WL interventions.

Impact of Left Ventricular Ejection Fraction on Clinical Outcomes in Bicuspid Aortic Valve Disease.

BACKGROUND: The prognostic impact of left ventricular ejection fraction (LVEF) in patients with bicuspid aortic valve (BAV) disease has not been previously studied. OBJECTIVES: The purpose of this study was to determine the prognostic impact of LVEF in BAV patients according to the type of aortic valve dysfunction. METHODS: We retrospectively analyzed the data collected in 2,672 patients included in an international registry of patients with BAV. Patients were classified according to the type of aortic valve dysfunction: isolated aortic stenosis (AS) (n = 749), isolated aortic regurgitation (AR) (n = 554), mixed aortic valve disease (MAVD) (n = 190), or no significant aortic valve dysfunction (n = 1,179; excluded from this analysis). The study population was divided according to LVEF strata to investigate its impact on clinical outcomes. RESULTS: The risk of all-cause mortality and the composite endpoint of aortic valve replacement or repair (AVR) and all-cause mortality increased when LVEF was <60% in the whole cohort as well as in the AS and AR groups, and when LVEF was <55% in MAVD group. In multivariable analysis, LVEF strata were significantly associated with increased rate of mortality (LVEF 50%-59%: HR: 1.83 [95% CI: 1.09-3.07]; P = 0.022; LVEF 30%-49%: HR: 1.97 [95% CI: 1.13-3.41]; P = 0.016; LVEF <30%: HR: 4.20 [95% CI: 2.01-8.75]; P < 0.001; vs LVEF 60%-70%, reference group). CONCLUSIONS: In BAV patients, the risk of adverse clinical outcomes increases significantly when the LVEF is <60%. These findings suggest that LVEF cutoff values proposed in the guidelines to indicate intervention should be raised from 50% to 60% in AS or AR and 55% in MAVD.

Left ventricular remodelling in bicuspid aortic valve disease.

AIMS: Characterization of left ventricular (LV) geometric pattern and LV mass could provide an important insight into the pathophysiological adaptations of the LV to pressure and/or volume overload in patients with bicuspid aortic valve (BAV) and significant (≥moderate) aortic valve (AV) disease. This study aimed to characterize LV remodelling and its prognostic impact in patients with BAV according to the predominant type of valvular dysfunction. METHODS AND RESULTS: In this international, multicentre BAV registry, 1345 patients [51.0 (37.0-63.0) years, 71% male] with significant AV disease were identified. Patients were classified as having isolated aortic stenosis (AS) (n = 669), isolated aortic regurgitation (AR) (n = 499) or mixed aortic valve disease (MAVD) (n = 177). LV hypertrophy was defined as a LV mass index >115 g/m2 in males and >95 g/m2 in females. LV geometric pattern was classified as (i) normal geometry: no LV hypertrophy, relative wall thickness (RWT) ≤0.42, (ii) concentric remodelling: no LV hypertrophy, RWT >0.42, (iii) concentric hypertrophy: LV hypertrophy, RWT >0.42, and (iv) eccentric hypertrophy: LV hypertrophy, RWT ≤0.42. Patients were followed-up for the endpoints of event-free survival (defined as a composite of AV repair/replacement and all-cause mortality) and all-cause mortality. Type of AV dysfunction was related to significant variations in LV remodelling. Higher LV mass index, i.e. LV hypertrophy, was independently associated with the composite endpoint for patients with isolated AS [hazard ratio (HR) 1.08 per 25 g/m2, 95% confidence interval (CI) 1.00-1.17, P = 0.046] and AR (HR 1.19 per 25 g/m2, 95% CI 1.11-1.29, P < 0.001), but not for those with MAVD. The presence of concentric remodelling, concentric hypertrophy and eccentric hypertrophy were independently related to the composite endpoint in patients with isolated AS (HR 1.54, 95% CI 1.06-2.23, P = 0.024; HR 1.68, 95% CI 1.17-2.42, P = 0.005; HR 1.59, 95% CI 1.03-2.45, P = 0.038, respectively), while concentric hypertrophy and eccentric hypertrophy were independently associated with the combined endpoint for those with isolated AR (HR 2.49, 95% CI 1.35-4.60, P = 0.004 and HR 3.05, 95% CI 1.71-5.45, P < 0.001, respectively). There was no independent association observed between LV remodelling and the combined endpoint for patients with MAVD. CONCLUSIONS: LV hypertrophy or remodelling were independently associated with the composite endpoint of AV repair/replacement and all-cause mortality for patients with isolated AS and isolated AR, although not for patients with MAVD.

Prognostic Implications of Associated Cardiac Abnormalities Detected on Echocardiography in Patients With Moderate Aortic Stenosis.

OBJECTIVES: This study aimed to evaluate the prevalence and prognostic value of the extent of extra-aortic valvular cardiac abnormalities in a large multicenter registry of patients with moderate AS. BACKGROUND: The prognostic significance of a new classification system that incorporates the extent of cardiac injury (beyond the aortic valve) has been proposed in patients with severe aortic stenosis (AS). Whether this can be applied to patients with moderate AS is unclear. METHODS: Based on the echocardiographic findings at the time of diagnosis of moderate AS (aortic valve area between 1.0 and 1.5 cm2 and dimensionless velocity index ratio of ≥0.25), a total of 1,245 patients were included and analyzed retrospectively. They were recategorized into 5 groups according to the extent of extra-aortic valvular cardiac abnormalities: none (Group 0), involving the left ventricle (Group 1), the left atrial or mitral valve (Group 2), the pulmonary artery vasculature or tricuspid valve (Group 3), or the right ventricle (Group 4). Patients were followed for all-cause mortality and combined endpoint (all-cause mortality, stroke, heart failure, or myocardial infarction). RESULTS: The distribution of patients according to the proposed classification was 13.1%, 26.8%, 42.6%, 10.6%, and 6.9% in Groups 0, 1, 2, 3, and 4, respectively. During a median follow-up of 4.3 (2.4 to 6.9) years, 564 (45.3%) patients died. There was a significant higher mortality rates with increasing extent of extra-aortic valvular cardiac abnormalities (log-rank p < 0.001). On multivariable analysis, the presence of extra-aortic valvular cardiac abnormalities remained independently associated with all-cause mortality and combined outcome, adjusted for aortic valve replacement as a time-dependent covariable. In particular, Group 2 and above were independently associated with all-cause mortality. CONCLUSIONS: In patients with moderate AS, the presence of extra-aortic valvular cardiac abnormalities is associated with poor outcome.

Diabesity: the combined burden of obesity and diabetes on heart disease and the role of imaging.

Diabesity is a term used to describe the combined adverse health effects of obesity and diabetes mellitus. The worldwide dual epidemic of obesity and type 2 diabetes is an important public health issue. Projections estimate a sixfold increase in the number of adults with obesity in 40 years and an increase in the number of individuals with diabetes to 642 million by 2040. Increased adiposity is the strongest risk factor for developing diabetes. Early detection of the effects of diabesity on the cardiovascular system would enable the optimal implementation of effective therapies that prevent atherosclerosis progression, cardiac remodelling, and the resulting ischaemic heart disease and heart failure. Beyond conventional imaging techniques, such as echocardiography, CT and cardiac magnetic resonance, novel post-processing tools and techniques provide information on the biological processes that underlie metabolic heart disease. In this Review, we summarize the effects of obesity and diabetes on myocardial structure and function and illustrate the use of state-of-the-art multimodality cardiac imaging to elucidate the pathophysiology of myocardial dysfunction, prognosticate long-term clinical outcomes and potentially guide treatment strategies.

Leaflet immobility and thrombosis in transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) has grown exponentially worldwide in the last decade. Due to the higher bleeding risks associated with oral anticoagulation and in patients undergoing TAVR, antiplatelet therapy is currently considered first-line antithrombotic treatment after TAVR. Recent studies suggest that some patients can develop subclinical transcatheter heart valve (THV) thrombosis after the procedure, whereby thrombus forms on the leaflets that can be a precursor to leaflet dysfunction. Compared with echocardiography, multidetector computed tomography is more sensitive at detecting THV thrombosis. Transcatheter heart valve thrombosis can occur while on dual antiplatelet therapy with aspirin and thienopyridine but significantly less with anticoagulation. This review summarizes the incidence and diagnostic criteria for THV thrombosis and discusses the pathophysiological mechanisms that may lead to thrombus formation, its natural history, potential clinical implications and treatment for these patients.

Incremental value of left ventricular global longitudinal strain in a newly proposed staging classification based on cardiac damage in patients with severe aortic stenosis.

AIMS: Cardiac damage in severe aortic stenosis (AS) can be classified according to a recently proposed staging classification. The present study investigated the incremental prognostic value of left ventricular (LV) global longitudinal strain (GLS) over stages of cardiac damage in patients with severe AS. METHODS AND RESULTS: From an ongoing registry, a total of 616 severe symptomatic AS patients with available LV GLS by speckle tracking echocardiography were selected and retrospectively analysed. Patients were categorized according to cardiac damage on echocardiography: Stage 0 (no damage), Stage 1 (LV damage), Stage 2 (mitral valve or left atrial damage), Stage 3 (tricuspid valve or pulmonary artery vasculature damage), or Stage 4 (right ventricular damage). LV GLS was divided by quintiles and assigned to the different stages. The endpoint was all-cause mortality. Over a median follow-up of 44 [24-89] months, 234 (38%) patients died. LV GLS was associated with all-cause mortality independent of stage of cardiac damage. After incorporation of LV GLS by quintiles into the staging classification, Stages 2-4 were independently associated with outcome. LV GLS showed incremental prognostic value over clinical characteristics and stages of cardiac damage. CONCLUSION: In this large single-centre cohort of severe AS patients, incorporation of LV GLS by quintiles in a novel proposed staging classification resulted in refinement of risk stratification by identifying patients with more advanced cardiac damage. LV GLS was shown to provide incremental prognostic value over the originally proposed staging classification.