Widening ethnic inequities in heart failure incidence in New Zealand

OBJECTIVE

Ethnic inequities in heart failure (HF) have been documented in several countries. This study describes New Zealand (NZ) trends in incident HF hospitalisation by ethnicity between 2006 and 2018.

METHODS

Incident HF hospitalisations in ≥20-year-old subjects were identified through International Classification of Diseases, 10th Revision-coded national hospitalisation records. Incidence was calculated for different ethnic, sex and age groups and were age standardised. Trends were estimated with joinpoint regression.

RESULTS

Of 116 113 incident HF hospitalisations, 12.8% were Māori, 5.7% Pacific people, 3.0% Asians and 78.6% Europeans/others. 64% of Māori and Pacific patients were aged <70 years, compared with 37% of Asian and 19% of European/others. In 2018, incidence rate ratios compared with European/others were 6.0 (95% CI 4.9 to 7.3), 7.5 (95% CI 6.0 to 9.4) and 0.5 (95% CI 0.3 to 0.8) for Māori, Pacific people and Asians aged 20-49 years; 3.7 (95% CI 3.4 to 4.0), 3.6 (95% CI 3.2 to 4.1) and 0.5 (95% CI 0.4 to 0.6) for Māori, Pacific people and Asians aged 50-69 years; and 1.5 (95% CI 1.4 to 1.6), 1.5 (95% CI 1.3 to 1.7) and 0.5 (95% CI 0.5 to 0.6) for Māori, Pacific people and Asians aged ≥70 years. Between 2006 and 2018, ethnicity-specific rates diverged in ≥70-year-old subjects due to a decline in European/others (annual percentage change (APC) -2.0%, 95% CI -2.5% to -1.6%) and Asians (APC -3.3%, 95% CI -4.4% to -2.1%), but rates remained unchanged for Māori and Pacific people. In contrast, regardless of ethnicity, rates either increased or remained unchanged in <70-year-old subjects.

CONCLUSION

Ethnic inequities in incident HF hospitalisation have widened in NZ over the past 13 years. Urgent action is required to address the predisposing factors that lead to development of HF in Maori and Pacific people.

Titration of medications and outcomes in multi-ethnic heart failure cohorts (with reduced ejection fraction) from Singapore and New Zealand

AIMS

We investigated titration patterns of angiotensin-converting enzyme inhibitors (ACEis)/angiotensin receptor blockers (ARBs) and beta-blockers, quality of life (QoL) over 6 months, and associated 1 year outcome [all-cause mortality/heart failure (HF) hospitalization] in a real-world population with HF with reduced ejection fraction (HFrEF).

METHODS AND RESULTS

Participants with HFrEF (left ventricular ejection fraction <40%) from a prospective multi-centre study were examined for use and dose [relative to guideline-recommended maintenance dose (GRD)] of ACEis/ARBs and beta-blockers at baseline and 6 months. 'Stay low' was defined as <50% GRD at both time points, 'stay high' as ≥50% GRD, and 'up-titrate' and 'down-titrate' as dose trajectories. Among 1110 patients (mean age 63 ± 13 years, 16% women, 26% New York Heart Association Class III/IV), 714 (64%) were multi-ethnic Asians from Singapore and 396 were from New Zealand (mainly European ethnicity). Baseline use of either ACEis/ARBs or beta-blockers was high (87%). Loop diuretic was prescribed in >80% of patients, mineralocorticoid receptor antagonist in about half of patients, and statins in >90% of patients. At baseline, only 11% and 9% received 100% GRD for each drug class, respectively, with about half (47%) achieving ≥50% GRD for ACEis/ARBs or beta-blockers. At 6 months, a large majority remained in the 'stay low' category, one third remained in 'stay high', whereas 10-16% up-titrated and 4-6% down-titrated. Patients with lower (vs. higher) N-terminal pro-beta-type natriuretic peptide levels were more likely to be up-titrated or be in 'stay high' for ACEis/ARBs and beta-blockers (P = 0.002). Ischaemic aetiology, prior HF hospitalization, and enrolment in Singapore (vs. New Zealand) were independently associated with higher odds of 'staying low' (all P < 0.005) for prescribed doses of ACEis/ARBs and beta-blockers. Adjusted for inverse probability weighting, ≥100% GRD for ACEis/ARBs [hazard ratio (HR) = 0.42; 95% confidence interval (CI) 0.24-0.73] and ≥50% GRD for beta-blockers (HR = 0.58; 95% CI 0.37-0.90) (vs. Nil) were associated with lower hazards for 1 year composite outcome. Country of enrolment did not modify the associations of dose categories with 1 year composite outcome. Higher medication doses were associated with greater improvements in QoL.

CONCLUSIONS

Although HF medication use at baseline was high, most patients did not have these medications up-titrated over 6 months. Multiple clinical factors were associated with changes in medication dosages. Further research is urgently needed to investigate the causes of lack of up-titration of HF therapy (and its frequency), which could inform strategies for timely up-titration of HF therapy based on clinical and biochemical parameters.

Identifying Candidate Circulating RNA Markers for Coronary Artery Disease by Deep RNA-Sequencing in Human Plasma

Advances in RNA sequencing (RNA-Seq) have facilitated transcriptomic analysis of plasma for the discovery of new diagnostic and prognostic markers for disease. We aimed to develop a short-read RNA-Seq protocol to detect mRNAs, long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in plasma for the discovery of novel markers for coronary artery disease (CAD) and heart failure (HF). Circulating cell-free RNA from 59 patients with stable CAD (half of whom developed HF within 3 years) and 30 controls was sequenced to a median depth of 108 paired reads per sample. We identified fragments from 3986 messenger RNAs (mRNAs), 164 long non-coding RNAs (lncRNAs), 405 putative novel lncRNAs and 227 circular RNAs in plasma. Circulating levels of 160 mRNAs, 10 lncRNAs and 2 putative novel lncRNAs were altered in patients compared with controls (absolute fold change >1.2, p < 0.01 adjusted for multiple comparisons). The most differentially abundant transcripts were enriched in mRNAs encoded by the mitochondrial genome. We did not detect any differences in the plasma RNA profile between patients who developed HF compared with those who did not. In summary, we show that mRNAs, lncRNAs and circular RNAs can be reliably detected in plasma by deep RNA-Seq. Multiple coding and non-coding transcripts were altered in association with CAD, including several mitochondrial mRNAs, which may indicate underlying myocardial ischaemia and oxidative stress. If validated, circulating levels of these transcripts could potentially be used to help identify asymptomatic individuals with established CAD prior to an acute coronary event.

An automated method for BRISQUE quantification of image quality in echocardiography

Background

Echocardiography (echo) remains the most widely used imaging modality for the assessment, monitoring, and prognostication of the heart. Despite its prevalence, standardisation efforts for echo chamber quantification are ongoing, with challenges owing to subjectivity during acquisition and analysis. Furthermore, the confidence in derived functional indices is often dependent on the quality of the acquired images. However, few studies have investigated the accuracy of echo measurements compared to a reference modality such as cardiac magnetic resonance (CMR) imaging, when stratified by image quality.

Purpose

To develop an objective and automated method to quantify echo image quality, and subsequently to investigate the relationship between image quality and patient demographics, as well as the magnitude of bias in left ventricular (LV) functional indices compared with CMR.

Methods

Transthoracic apical 2D echo (2DE) and 3D echo (3DE) data from 128 participants (72 healthy controls and 56 patients with acquired heart disease) were used to train a BRISQUE (Blind/Referenceless Image Spatial Quality Evaluator) algorithm [1]. Briefly, feature extraction was performed by fitting pixel luminances to a generalised Gaussian distribution (GGD), followed by support vector regression to correlate features (i.e., shape, variance, and mean parameters of the GGD) to quality scores (Fig. 1). Independent BRISQUE models were trained on 580 2DE images (consisting of 2-, 3-, and 4-chamber views) and 128 targeted LV 3DE acquisitions at end-diastole, each assigned a subjective perceived quality score between 1 (poor) and 9 (excellent) by a single observer. LV indices including end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), and global longitudinal strain (GLS), were assessed according to standard guidelines. Resultant BRISQUE scores were plotted against patient demographics (age, height, weight) and the measurement bias by comparison to CMR (acquired within 1 hour of echo).

Results

Several linear relationships (where P-value of slope &lt;0.05) were observed between demographics, cardiac indices, and BRISQUE scores. Increasing patient weight (and height in 3DE) were found to be associated with poorer image quality. There was no apparent relationship between image quality and age. Of interest, EF exhibited a relationship with image quality in both 2DE and 3DE (Fig. 2), whereby higher quality images tended to overestimate EF, while lower quality images underestimated EF. For 3DE, image quality dependency was also observed for ESV and GLS biases.

Conclusions

BRISQUE can objectively quantify image quality to produce scores which correlate to those of an expert observer, with potential utility for the standardised quantification of echo image quality. Using this method, it may be possible to predict patient characteristics which adversely impact echo quality, as well as the magnitude of measurement biases for certain functional indices.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council (HRC) of New Zealand; National Heart Foundation (NHF) of New Zealand

Right ventricular quantification using 3D echocardiography: a comparison with CMR

Background

Volumetric and functional right ventricular (RV) indices such as ejection fraction (EF) and global strains are known independent predictors of adverse cardiovascular events. While cardiac magnetic resonance (CMR) imaging remains the reference standard for volume quantification, echocardiography is more accessible and allows for rapid ventricular assessment. Compared to conventional 2D echocardiography, 3D echocardiography (3DE) enables full volume acquisitions and the ability to circumvent geometric assumptions. Given the complexity of RV geometry and sensitivity to image plane positioning, this advantage offers the potential to obtain more accurate diagnostic measurements.

Purpose

Tools for RV analysis in 3DE have been less extensively studied compared to those for the left ventricle (LV). We sought to quantify discrepancies in RV indices derived from 3DE and CMR.

Methods

Transthoracic real-time 3DE and cine CMR imaging were performed in 20 prospectively recruited participants (12 patients with acquired cardiac disease and 8 healthy controls), &lt;1 hour apart. Dynamic 3D biventricular models were constructed semi-automatically from CMR by identifying fiducial landmarks, correcting in-plane breath-hold mis-registrations, and interactively fitting contours to the endocardial and epicardial borders on long- and short-axis slices. For 3DE, right ventricular endocardial models were created by fitting contours on 2D image planes resampled from the 3D volume at end-diastole and end-systole, which were subsequently tracked over one cardiac cycle (Figure 1). RV indices including end-diastolic volume (EDV), end-systolic volume (ESV), EF, global longitudinal strain (GLS), and global circumferential strain (GCS) were calculated from the 3DE- and CMR-derived 3D geometric models and compared. Paired-sample t-tests were performed to identify statistically significant differences (where P&lt;0.05), and intraclass correlation coefficients (ICC) for absolute agreement were computed to assess the reliability for each measurement.

Results

Differences (mean ± SD) in RV indices between 3DE and CMR, with corresponding ICCs are presented in Table 1. Statistically significant differences in RV EDV, ESV, EF, and GLS were observed, with 3DE consistently underestimating volumes and overestimating function when compared to CMR. Although a statistically significant difference in RV GCS was not observed, a low ICC score indicated poor reliability.

Conclusions

Volume underestimation in RV indices between 3DE and CMR were found to be larger than those previously reported for the LV, which is likely due to the increased geometric complexity and surface area to volume ratio for the RV. Moreover, 3DE tends to overestimate RV function in terms of EF and GLS, which may impact treatment pathways if used in a clinical setting. Recognising systematic differences between modalities reinforces the need to further develop 3DE technologies for more accurate RV quantification.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council (HRC) of New Zealand;National Heart Foundation (NHF) of New Zealand

Leveraging CMR for 3D echocardiography: an annotated multimodality dataset for AI

Funding Acknowledgements: Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council of New Zealand (HRC)

National Heart Foundation of New Zealand (NHF)

Segmentation of the left ventricular myocardium and cavity in 3D echocardiography (3DE) is a critical task for the quantification of systolic function in heart disease. Continuing advances in 3DE have considerably improved image quality, prompting increased clinical uptake in recent years, particularly for volumetric measurements. Nevertheless, analysis of 3DE remains a difficult problem due to inherently complex noise characteristics, anisotropic image resolution, and regions of acoustic dropout.

One of the primary challenges associated with the development of automated methods for 3DE analysis is the requirement of a sufficiently large training dataset. Historically, ground truth annotations have been difficult to obtain due to the high degree of inter- and intra-observer variability associated with manual 3DE segmentation, thus, limiting the scope of AI-based solutions. To address the lack of expert consensus, we instead used labels derived from cardiac magnetic resonance (CMR) images of the same subjects. By spatiotemporally registering CMR labels to corresponding 3DE image data on a per subject basis (Figure 1), we collated 520 annotated 3DE images from a mixed cohort of 130 human subjects (2 independent single-beat acquisitions per subject at end-diastole and end-systole) consisting of healthy controls and patients with acquired cardiac disease. Comprising images acquired across a range of patient demographics, this curated dataset exhibits variation in image quality, 3DE acquisition parameters, as well as left ventricular shape and pose within the 3D image volume.

To demonstrate the utility of such a dataset, nn-UNet, a self-configuring deep learning method for semantic segmentation was employed. An 80/20 split of the dataset was used for training and testing, respectively, and data augmentations were applied in the form of scaling, rotation, and reflection. The trained network was capable of reproducing measurements derived from CMR for end-diastolic volume, end-systolic volume, ejection fraction, and mass, while outperforming an expert human observer in terms of accuracy as well as scan-rescan reproducibility (Table I).

As part of ongoing efforts to improve the accuracy and efficiency of 3DE analysis, we have leveraged the high resolution and signal-to-noise-ratio of CMR (relative to 3DE), to create a novel, publicly available benchmark dataset for developing and evaluating 3DE labelling methods. This approach not only significantly reduces the effects of observer-specific bias and variability in training data arising from conventional manual 3DE analysis methods, but also improves the agreement between cardiac indices derived from 3DE and CMR.

Figure 1. Data annotation workflow Table I. Results

Left ventricular dimensions and mass measurement from 3D echocardiography: are we there yet?

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council (HRC) of New Zealand and National Heart Foundation (NHF) of New Zealand

Introduction—Echocardiographic measures of left ventricular (LV) structure and size, including LV wall thickness and LV end-diastolic dimension (LVID), provide important information in the assessment of patients with heart disease. For example, LV mass is a predictor of outcome for patients with hypertension and LVID is a predictor of cardiac resynchronisation response in patients with heart failure. Advances in 3D echocardiography (3DE) have enabled full-volume acquisitions, which overcome geometric assumptions present in conventional 2D echocardiography (2DE), providing a more accurate representation of cardiac geometry. Although numerous validation studies have been performed for 3DE-derived LV volumes, comparisons of LV dimension by 3DE against established methods are limited.

Purpose—We sought to compare routine LV dimension measurements between 3DE and 2DE, with validation using cardiac magnetic resonance (CMR) imaging.

Methods—Transthoracic echocardiography (2D and 3D) and cine CMR imaging were performed in 62 prospectively recruited participants (47 healthy controls, 9 patients with LVH, 6 patients with aortic regurgitation), &lt;1 h apart. 2DE LV dimension measurements (interventricular septum [IVS], posterior wall thickness [PWT], and LVID) were taken at end-diastole from the parasternal long axis, and mass was calculated using the linear method based on ASE/EACVI guidelines. For 3DE, 3D geometric models of the LV were constructed by interactively fitting surfaces to the endocardium and epicardium using previously validated software, from which corresponding LV dimension measurements and mass were extracted. Measurements were obtained from CMR by a similar 3D geometric modelling process.

Results—Differences (mean ± SD) in LV dimension measurements between the three modalities and intraclass correlation coefficients (ICC) are presented in Table I. When compared with CMR, 3DE exhibited higher agreement in terms of LVID and mass than 2DE, but lower agreement in wall thickness measurements. Statistically significant differences were found between 2DE and 3DE for PWT, LVID, and mass, as well as 2DE and CMR for LVID and mass (where P &lt; 0.01 for a paired sample t­-test, marked with an asterisk). Meanwhile, there were no statistically significant differences between 3DE and CMR for IVS, PWT, LVID, or mass.

Conclusions—Our results demonstrate that 3DE is superior to 2DE in terms of LVID and mass quantification, exhibiting good agreement with CMR. 3DE exhibited moderate and poor agreement for IVS and PWT, respectively, with both 2DE and CMR, likely due to the lower spatial resolution of 3DE. Further advances in 3DE image quality and analysis tools are therefore needed to improve accuracy of wall thickness measurements. Since 2DE imaging plane and probe positioning can result in oblique measurement and underestimation of LVID, the assessment of LVID and mass by 3DE is likely to lead to more accurate diagnostic and prognostic outcomes. Abstract Table 1

Contrasting trends in heart failure incidence in younger and older New Zealanders, 2006-2018

OBJECTIVE

Studies indicate that age-standardised heart failure (HF) incidence has been decreasing internationally; however, contrasting trends in different age groups have been reported, with rates increasing in younger people and decreasing in the elderly. We aimed to describe age-specific trends in HF incidence in New Zealand (NZ).

METHODS

In this nationwide data linkage study, we used routinely collected hospitalisation data to identify incident HF hospitalisations in NZ residents aged ≥20 years between 2006 and 2018. Age-specific and age-standardised incidence rates were calculated for each calendar year. Joinpoint regression was used to compare incidence trends.

RESULTS

116 113 incident HF hospitalisations were identified over the 13-year study period. Between 2006 and 2013, age-standardised incidence decreased from 403 to 323 per 100 000 (annual percentage change (APC) -2.6%, 95% CI -3.6 to -1.6%). This reduction then plateaued between 2013 and 2018 (APC 0.8%, 95% CI -0.8 to 2.5%). Between 2006 and 2018, rates in individuals aged 20-49 years old increased by 1.5% per year (95% CI 0.3 to 2.7%) and decreased in those aged ≥80 years old by 1.2% per year (95% CI -1.7 to -0.7%). Rates in individuals aged 50-79 years old initially declined from 2006 to 2013, and then remained stable or increased from 2013 to 2018. The proportion of HF hospitalisations associated with ischaemic heart disease decreased from 35.1% in 2006 to 28.0% in 2018.

CONCLUSION

HF remains an important problem in NZ. The decline in overall incidence has plateaued since 2013 due to increasing rates of HF in younger age groups despite an ongoing decline in the elderly.

Longitudinal strain measurement by 3D modelling from cine CMR: feasibility and comparison to 2D speckle tracking echocardiography

Background

Global longitudinal strain (GLS) has emerged as a sensitive index of left ventricular (LV) systolic function with greater prognostic value than LV ejection fraction (LVEF) in a variety of cardiac disorders. While GLS is routinely derived from 2D speckle tracking echocardiography (STE) and feature tracking in cardiac magnetic resonance (CMR) imaging, calculation of strain via 3D geometric modelling enables analyses of deformation that are independent of 2D image plane constraints.

Purpose

We sought to compare longitudinal strain measurements extracted from geometric 3D analysis of CMR against values obtained from conventional 2D-STE.

Methods

Consecutive 2D-echocardiography (2D-echo) and steady-state free precession multiplanar cine CMR scans were performed in 80 prospectively recruited participants (48 healthy controls with LVEF range 53–74%, 30 patients with non-ischaemic cardiac disease with LVEF range 25–77%, and 2 heart transplant recipients with LVEF 53% and 58%), &lt;1 hour apart. Average endocardial peak GLS from 2D-STE was calculated offline using vendor-independent clinical software from apical triplane (2, 3 and 4-chamber) images for each of the standardised LV walls (anterior, anteroseptal, inferoseptal, inferior, inferolateral, anterolateral). Dynamic 3D geometric models of the LV were reconstructed from 3 long- and 6 short-axis CMR slices over one cardiac cycle. Corresponding longitudinal strain measurements were then evaluated by extracting analogous endocardial arc lengths (apex to base of each LV wall) from the 3D LV model. Finally, an average peak GLS was calculated as the mean of the peak longitudinal strains in each LV wall.

Results

GLS measured by 2D-STE ranged between −6.5% and −27.9% for the study population. A two-way mixed-effects intraclass correlation coefficient (ICC) for absolute agreement of 0.820 (95% CI: [0.720, 0.885]) demonstrated good correlation between average GLS obtained from 2D-STE and CMR. A Bland-Altman analysis revealed a minimal bias (&lt;1%) and 95% limits of agreement (LOA) between −6.3% and 5.5% (Fig. 1), with no apparent proportional bias. Comparatively lower correlation and wider LOA between longitudinal strains from 2D-STE and CMR were observed for each LV wall (Table I).

Conclusions

Fully automated calculation of LV GLS can be obtained from geometric 3D CMR analysis. Average peak GLS from cine CMR exhibits good agreement with 2D-STE, despite showing only moderate agreement at each LV wall. The increased discrepancy in regional longitudinal strain may be attributed to subjective plane positioning in 2D-echo, which can be expected to improve with advances in 3D-STE. The calculation of GLS by 3D geometric modelling may enhance the diagnostic value of routine cine CMR examinations for LV systolic function assessment.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Health Research Council (HRC) of New Zealand and National Heart Foundation (NHF) of New Zealand Figure 1. Bland-Altman analysisTable I. Regional correlations

Temporal trends in the burden of heart failure

Heart failure is a common healthcare problem associated with high morbidity and mortality. The burden of heart failure is changing; increases secondary to an ageing population may be offset by improved primary cardiovascular prevention and advances in heart failure therapies. In this review, we evaluate recent international trends in heart failure incidence, morbidity and mortality. Although the age-standardised incidence of heart failure has been decreasing since 2000, the incidence in those age groups <55 years is increasing with patients being diagnosed at younger ages. Despite improvements in therapies for heart failure, prognosis still remains poor with up to one-third of patients not surviving beyond 1 year following diagnosis and no improvements in mortality over the past 10 years. The case-mix of heart failure patients is changing with a greater proportion having non-ischaemic aetiology and preserved ejection fraction, and a higher prevalence of non-cardiovascular comorbidity and mortality.

Automated analysis of 3D-echocardiography using spatially registered patient-specific CMR meshes

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Heart Foundation (NHF) of New Zealand Health Research Council (HRC) of New Zealand

Artificial intelligence shows considerable promise for automated analysis and interpretation of medical images, particularly in the domain of cardiovascular imaging. While application to cardiac magnetic resonance (CMR) has demonstrated excellent results, automated analysis of 3D echocardiography (3D-echo) remains challenging, due to the lower signal-to-noise ratio (SNR), signal dropout, and greater interobserver variability in manual annotations. As 3D-echo is becoming increasingly widespread, robust analysis methods will substantially benefit patient evaluation. 

We sought to leverage the high SNR of CMR to provide training data for a convolutional neural network (CNN) capable of analysing 3D-echo. We imaged 73 participants (53 healthy volunteers, 20 patients with non-ischaemic cardiac disease) under both CMR and 3D-echo (&lt;1 hour between scans). 3D models of the left ventricle (LV) were independently constructed from CMR and 3D-echo, and used to spatially align the image volumes using least squares fitting to a cardiac template. The resultant transformation was used to map the CMR mesh to the 3D-echo image. Alignment of mesh and image was verified through volume slicing and visual inspection (Fig. 1) for 120 paired datasets (including 47 rescans) each at end-diastole and end-systole.

100 datasets (80 for training, 20 for validation) were used to train a shallow CNN for mesh extraction from 3D-echo, optimised with a composite loss function consisting of normalised Euclidian distance (for 290 mesh points) and volume. Data augmentation was applied in the form of rotations and tilts (&lt;15 degrees) about the long axis. The network was tested on the remaining 20 datasets (different participants) of varying image quality (Tab. I). For comparison, corresponding LV measurements from conventional manual analysis of 3D-echo and associated interobserver variability (for two observers) were also estimated.

Initial results indicate that the use of embedded CMR meshes as training data for 3D-echo analysis is a promising alternative to manual analysis, with improved accuracy and precision compared with conventional methods. Further optimisations and a larger dataset are expected to improve network performance.

(n = 20) LV EDV (ml) LV ESV (ml) LV EF (%) LV mass (g) Ground truth CMR 150.5 ± 29.5 57.9 ± 12.7 61.5 ± 3.4 128.1 ± 29.8 Algorithm error -13.3 ± 15.7 -1.4 ± 7.6 -2.8 ± 5.5 0.1 ± 20.9 Manual error -30.1 ± 21.0 -15.1 ± 12.4 3.0 ± 5.0 Not available Interobserver error 19.1 ± 14.3 14.4 ± 7.6 -6.4 ± 4.8 Not available Tab. 1. LV mass and volume differences (means ± standard deviations) for 20 test cases. Algorithm: CNN – CMR (as ground truth). Abstract Figure. Fig 1. CMR mesh registered to 3D-echo.

Development and validation of a cardiovascular risk score for patients in the community after acute coronary syndrome

OBJECTIVE

Following acute coronary syndrome (ACS), patients are managed long-term in the community, yet few tools are available to guide patient-clinician communication about risk management in that setting. We developed a score for predicting cardiovascular disease (CVD) risk among patients managed in the community after ACS.

METHODS

Adults aged 30-79 years with prior ACS were identified from a New Zealand primary care CVD risk management database (PREDICT) with linkage to national mortality, hospitalisation, pharmaceutical dispensing and regional laboratory data. A Cox model incorporating clinically relevant factors was developed to estimate the time to a subsequent fatal or non-fatal CVD event and transformed into a 5-year risk score. External validation was performed in patients (Coronary Disease Cohort Study) assessed 4 months post-ACS.

RESULTS

The PREDICT-ACS cohort included 13 703 patients with prior hospitalisation for ACS (median 1.9 years prior), 69% men, 58% European, median age 63 years, who experienced 3142 CVD events in the subsequent 5 years. Median estimated 5 year CVD risk was 24% (IQR 17%-35%). The validation cohort consisted of 2014 patients, 72% men, 92% European, median age 67 years, with 712 CVD events in the subsequent 5 years. Median estimated 5-year risk was 33% (IQR 24%-51%). The risk score was well calibrated in the derivation and validation cohorts, and Harrell's c-statistic was 0.69 and 0.68, respectively.

CONCLUSIONS

The PREDICT-ACS risk score uses data routinely available in community care to predict the risk of recurrent clinical events. It was derived and validated in real-world contemporary populations and can inform management decisions with patients living in the community after experiencing an ACS.

Convalescent troponin and cardiovascular death following acute coronary syndrome

OBJECTIVES

High-sensitivity cardiac troponin testing is used in the diagnosis of acute coronary syndromes but its role during convalescence is unknown. We investigated the long-term prognostic significance of serial convalescent high-sensitivity cardiac troponin concentrations following acute coronary syndrome.

METHODS

In a prospective multicentre observational cohort study of 2140 patients with acute coronary syndrome, cardiac troponin I concentrations were measured in 1776 patients at 4 and 12 months following the index event. Patients were stratified into three groups according to the troponin concentration at 4 months using the 99th centile (women>16 ng/L, men>34 ng/L) and median concentration of those within the reference range. The primary outcome was cardiovascular death.

RESULTS

Troponin concentrations at 4 months were measurable in 99.0% (1759/1776) of patients (67±12 years, 72% male), and were ≤5 ng/L (median) and >99th centile in 44.8% (795) and 9.3% (166), respectively. There were 202 (11.4%) cardiovascular deaths after a median of 4.8 years. After adjusting for the Global Registry of Acute Coronary Events score, troponin remained an independent predictor of cardiovascular death (HR 1.4, 95% CI 1.3 to 1.5 per doubling) with the highest risk observed in those with increasing concentrations at 12 months. Patients with 4-month troponin concentrations >99th centile were at increased risk of cardiovascular death compared with those ≤5 ng/L (29.5% (49/166) vs 4.3% (34/795); adjusted HR 4.9, 95% CI 3.8 to 23.7).

CONCLUSIONS

Convalescent cardiac troponin concentrations predict long-term cardiovascular death following acute coronary syndrome. Recognising this risk by monitoring troponin may improve targeting of therapeutic interventions.

TRIAL REGISTRATION NUMBER

ACTRN12605000431628;Results.

P5719Plasma proteomics identify plaque-related proteins that predict long-term recurrent coronary events in patients with acute coronary syndrome

Background

Coronary plaque burden and composition drive recurrent ischaemic events in coronary artery disease.

Purpose

We first investigated the association between plasma proteins and coronary plaque characteristics in a cohort of asymptomatic individuals with low-intermediate Framingham Risk Score. Plaque-related proteins were further evaluated in a second cohort of patients with acute coronary syndrome (ACS) to determine their prognostic value for predicting future myocardial infarction (MI).

Methods

We profiled 1305 plasma proteins using an aptamer-based array (SOMAscan) in asymptomatic individuals who had undergone 384-slice coronary computed tomography angiography. Plaques were categorized by composition as calcified or non-calcified. First, we identified proteins that were different (based on multiple testing adjusted p-values: q-value <0.05) between 250 ACS patients who suffered a recurrent MI event on follow-up compared with another 250 ACS patients who remained event-free using Mann-Whitney U test. Next, protein candidates that also correlated (Pearson's p<0.05) with specific categories of plaque composition were evaluated using a cox proportional hazards model to determine the risk of recurrent MI, adjusting for potential confounders in the second cohort.

Results

A total of 65 and 120 plasma proteins were significantly associated with calcified and non-calcified plaques respectively in the asymptomatic cohort (N=79). Of these 185 proteins, 23 proteins were differentially expressed (DE) between ACS patients with and without recurrent MI events (median follow-up 1811 days). The top three up-and down-regulated proteins in the recurrent MI group were macrophage-capping protein, trefoil factor 3 and cystatin-SN (median FC 1.22, 1.17 and 1.17; q-value 4.34x10–6, 2.18x10–4, 3.17x10–3 respectively) and fibroblast growth factor 20, lymphotoxin a2/b1 and vascular endothelial growth factor receptor 2 (median FC 0.92, 0.94 and −0.090; q-value 1.31x10–3, 9.45x10–3 and 3.90x10–3) respectively. The quartiles of these protein concentrations were also associated with risk of recurrent MI, (log-rank test p-value range from 2.71x10–7 to 0.04). Of the DE proteins, the adjusted hazards ratio (HR) of cystatin-SN in the highest quartile (Q4) was 1.44 times that of the first quartile (Q1) (adjusted HR: 1.44, 95% CI: 0.93–2.2) and higher plasma concentration of cystatin-SN was associated with increasing risk of recurrent MI events (Trend test p=0.004). On the other hand, the highest quartile of fibroblast growth factor 20 was associated with 44% reduction in risks of recurrent MI adjusted HR: 0.56, 95% CI of HR: 0.35–0.87), with significant trend test (p=0.0096).

Conclusions

Large-scale plasma proteomics identified novel plaque-related proteins predictive of recurrent coronary events in patients with ACS. Further studies may help unravel the biological underpinnings of these circulating proteins and their potential as novel prognostic biomarkers.

Acknowledgement/Funding

This work was supported by grant NMRC/CSA-INV/0001/2016 from the National Medical Research Council, Singapore.

Patterns of multi-morbidity and prediction of hospitalisation and all-cause mortality in advanced age

Background

multi-morbidity is associated with poor outcomes and increased healthcare utilisation. We aim to identify multi-morbidity patterns and associations with potentially inappropriate prescribing (PIP), subsequent hospitalisation and mortality in octogenarians.

Methods

life and Living in Advanced Age; a Cohort Study in New Zealand (LiLACS NZ) examined health outcomes of 421 Māori (indigenous to New Zealand), aged 80-90 and 516 non-Māori, aged 85 years in 2010. Presence of 14 chronic conditions was ascertained from self-report, general practice and hospitalisation records and physical assessments. Agglomerative hierarchical cluster analysis identified clusters of participants with co-existing conditions. Multivariate regression models examined the associations between clusters and PIP, 48-month hospitalisations and mortality.

Results

six clusters were identified for Māori and non-Māori, respectively. The associations between clusters and outcomes differed between Māori and non-Māori. In Māori, those in the complex multi-morbidity cluster had the highest prevalence of inappropriately prescribed medications and in cluster 'diabetes' (20% of sample) had higher risk of hospitalisation and mortality at 48-month follow-up. In non-Māori, those in the 'depression-arthritis' (17% of the sample) cluster had both highest prevalence of inappropriate medications and risk of hospitalisation and mortality.

Conclusions

in octogenarians, hospitalisation and mortality are better predicted by profiles of clusters of conditions rather than the presence or absence of a specific condition. Further research is required to determine if the cluster approach can be used to target patients to optimise resource allocation and improve outcomes.

Developing and validating a cardiovascular risk score for patients in the community with prior cardiovascular disease

OBJECTIVE

Patients with atherosclerotic cardiovascular disease (CVD) vary significantly in their risk of future CVD events; yet few clinical scores are available to aid assessment of risk. We sought to develop a score for use in primary care that estimates short-term CVD risk in these patients.

METHODS

Adults aged <80 years with prior CVD were identified from a New Zealand primary care cohort study (PREDICT), and linked to national mortality, hospitalisation and dispensing databases. A Cox model with an outcome of myocardial infarction, stroke or CVD death within 2 years was developed. External validation was performed in a cohort from the UK.

RESULTS

24 927 patients, 63% men, 63% European, median age 65 years (IQR 58-72 years), experienced 1480 CVD events within 2 years after a CVD risk assessment. A risk score including ethnicity, comorbidities, body mass index, creatine creatinine and treatment, in addition to established risk factors used in primary prevention, predicted a median 2-year CVD risk of 5.0% (IQR 3.5%-8.3%). A plot of actual against predicted event rates showed very good calibration throughout the risk range. The score performed well in the UK cohort but overestimated risk for those at highest risk, who were predominantly patients defined as having heart failure.

CONCLUSIONS

The PREDICT-CVD secondary prevention score uses routine measurements from clinical practice that enable it to be implemented in a primary care setting. The score will facilitate risk communication between primary care practitioners and patients with prior CVD, particularly as a resource to show the benefit of risk factor modification.

Management and Long-Term Outcome of Acute Coronary Syndrome Patients Presenting with Heart Failure in a Contemporary New Zealand Cohort (ANZACS-QI 4)

BACKGROUND

Acute heart failure (HF) associated with an acute coronary syndrome (ACS) predicts adverse outcome. There have been important recent improvements in ACS management. Our aim was to describe the management and outcomes in those with and without HF in a contemporary ACS cohort.

METHODS

Consecutive patients presenting with ACS between 2007 and 2011 were enrolled in the All New Zealand Acute Coronary Syndrome Quality Improvement (ANZACS-QI) registry. Outcomes and medication dispensing were obtained using anonymised linkage to national data sets. A summary pharmacotherapy measure of "quadruple therapy" was defined as dispensing of at least one agent from each of the four evidence-based classes - anti-platelet, statin, angiotensin converting enzyme inhibitor/angiotensin receptor blocker and beta blocker.

RESULTS

Of 3743 ACS patients 14% had acute HF. Acute heart failure patients were older (69.2±12.6 vs 62.3±12.8 years, p<0.001), less likely to have coronary angiography (66% vs 86%, p<0.001) and revascularisation (46% vs 62%, p<0.001). Immediate post-discharge quadruple therapy was higher for those with than without HF (61% vs 55%, p=0.02) but fell to similar levels by one-year (45% vs 53%, p=0.55). At four years follow-up nearly half of those presenting with ACS and HF had died. After adjustment, HF remained a strong predictor of death within 28 days (OR 2.9, 95%CI 1.5 - 5.5) and beyond 28 days (HR 1.8, 95%CI 1.5 - 2.3).

CONCLUSION

Acute heart failure complicating ACS is associated with heightened risk of short-term and long-term mortality. One in three ACS patients with HF did not have coronary angiography and less than half received quadruple therapy a year after presentation.

A new approach to assessment of the left ventricle

Cardiac motion is a continuous process; however most measurements to assess cardiac function are taken at brief moments in the cardiac cycle. Using functional data analysis, repeated measurements of left ventricular volume recorded at each frame of a continuous image measured with cardiac ultrasound (echocardiography) were turned into a function of volume over time. The first derivative of the displacement of volume with respect to time is velocity; the second derivative is acceleration. Plotting volume, velocity, and acceleration against each other in a 3-dimensional plot results in a closed loop. The area within the loop is defined by the kinematics of volume change and so may represent ventricular function.

•

We have developed an approach to analyzing images of the left ventricle that incorporates information from throughout the cardiac cycle.

•

Comparing systolic and diastolic areas within a loop defined by volume, velocity, and acceleration of left ventricular volume highlights imbalances in the kinematics of the two phases, potentially indicating early sub-clinical disease.

•

Substantially more information about left ventricular function may be derived from a non-invasive clinically available tool such as echocardiography.

Is heart rate a risk marker in patients with chronic heart failure and concomitant atrial fibrillation? Results from the MAGGIC meta-analysis

AIM

To investigate the relationship between heart rate and survival in patients with heart failure (HF) and coexisting atrial fibrillation (AF).

METHODS AND RESULTS

Patients with AF included in the Meta-analysis Global Group in Chronic Heart Failure (MAGGIC) meta-analysis were the main focus of this analysis (3259 patients from 17 studies). The outcome was all-cause mortality at 3 years. Heart rate was analysed as a categorical (tertiles; T1 ≤77 b.p.m., T2 78-98 b.p.m., T3 ≥98 b.p.m.) and continuous variable. Cox proportional hazard models were used to compare the risk of all-cause death between tertiles of baseline heart rate. Patients in the highest tertile were more often female, less likely to have an ischaemic aetiology or diabetes, had a lower ejection fraction but higher blood pressure and New York Heart Association (NYHA) class. Higher heart rate was associated with higher mortality in patients with sinus rhythm (SR) but not in those in AF. In patients with heart failure and reduced ejection fraction (HF-REF) and AF, death rates per 100 patient years were lowest in the highest heart rate tertile (T1 18.9 vs. T3 15.9) but this difference was not statistically significant (P = 0.10). In patients with heart failure and preserved ejection fraction (HF-PEF), death rates per 100 patient years were highest in the highest heart rate tertile (T1 14.6 vs. T3 16.0, P = 0.014). However, after adjustment for other important prognostic variables, higher heart rate was no longer associated with higher mortality in HF-PEF (or HF-REF).

CONCLUSIONS

In this meta-analysis of patients with HF, heart rate does not have the same prognostic significance in patients in AF as it does in those in SR, irrespective of ejection fraction or treatment with beta-blocker.

Genetic markers of repolarization and arrhythmic events after acute coronary syndromes

BACKGROUND

There is a genetic contribution to the risk of ventricular arrhythmias in survivors of acute coronary syndromes (ACS). We wished to explore the role of 33 candidate single nucleotide polymorphisms (SNPs) in prolonged repolarization and sudden death in patients surviving ACS.

METHODS

A total of 2,139 patients (1680 white ethnicity) surviving an admission for ACS were enrolled in the prospective Coronary Disease Cohort Study. Extensive clinical, echocardiographic, and neurohormonal data were collected for 12 months, and clinical events were recorded for a median of 5 years. Each SNP was assessed for association with sudden cardiac death (SCD)/cardiac arrest (CA) and prolonged repolarization at 3 time-points: index admission, 1 month, and 12 months postdischarge.

RESULTS

One hundred six SCD/CA events occurred during follow-up (6.3%). Three SNPs from 3 genes (rs17779747 [KCNJ2], rs876188 [C14orf64], rs3864180 [GPC5]) were significantly associated with SCD/CA in multivariable models (after correction for multiple testing); the minor allele of rs17779747 with a decreased risk (hazard ratio [HR] 0.68 per copy of the minor allele, 95% CI 0.50-0.92, P = .012), and rs876188 and rs386418 with an increased risk (HR 1.52 [95% CI 1.10-2.09, P = .011] and HR 1.34 [95% CI 1.04-1.82, P = .023], respectively). At 12 months postdischarge, rs10494366 and rs12143842 (NOS1AP) were significant predictors of prolonged repolarization (HR 1.32 [95% CI 1.04-1.67, P = .022] and HR 1.30 [95% CI 1.01-1.66, P = .038], respectively), but not at earlier time-points.

CONCLUSION

Three SNPs were associated with SCD/CA. Repolarization time was associated with variation in the NOS1AP gene. This study demonstrates a possible role for SNPs in risk stratification for arrhythmic events after ACS.

Atrial fibrillation and cycling: six year follow-up of the Taupo bicycle study

BACKGROUND

Atrial Fibrillation (AF) is the most common sustained cardiac arrhythmia, and the incidence of AF is increased markedly among elite athletes. It is not clear how lesser levels of physical activity in the general population influence AF. We asked whether participation in the Taupo Cycle Challenge was associated with increased hospital admissions due to AF, and within the cohort, whether admissions for AF were related to frequency and intensity of cycling.

METHODS

Participants in the 2006 Lake Taupo Cycle Challenge, New Zealand's largest mass cycling event, were invited to complete an on-line questionnaire. Those who agreed (n = 2590, response rate = 43.1%) were followed up by record linkage via the National Minimum Health Database from December 1 2006 until June 30 2013, to identify admissions to hospital due to AF.

RESULTS

The age and gender standardized admission rate for AF was similar in the Taupo cohort (19.60 per 10,000 per year) and the national population over the same period (2006-2011) (19.45 per 10,000 per year). Within the study cohort (men only), for every additional hour spent cycling per week the risk changed by 0.90 (95% confidence interval 0.79 - 1.01). This result did not change appreciably after adjustment for age and height.

CONCLUSIONS

Hospital admission due to AF was not increased above the national rate in this group of non-elite cyclists, and within the group the rate of AF did not increase with amount of cycling. The level of activity undertaken by this cohort of cyclists was, on average, not sufficient to increase the risk of hospitalization for AF.

Higher prevalence of left ventricular hypertrophy in two Māori cohorts: findings from the Hauora Manawa/Community Heart Study

OBJECTIVES

Cardiovascular disease (CVD) is the leading cause of mortality in New Zealand with a disproportionate burden of disease in the Māori population. The Hauora Manawa Project investigated the prevalence of cardiovascular risk factors and CVD in randomly selected Māori and non-Māori participants. This paper reports the prevalence of structural changes in the heart.

METHODS

A total of 252 rural Māori, 243 urban Māori; and 256 urban non-Māori underwent echocardiography to assess cardiac structure and function. Multivariable logistic regression was used to determine variables associated with heart size.

RESULTS

Left ventricular (LV) mass measurements were largest in the rural Māori cohort (183.5,sd 61.4), intermediate in the urban Māori cohort (169.7,sd 57.1) and smallest in the non-Māori cohort (152.6,sd 46.7; p<0.001). Similar patterns were observed for other measurements and indexation had no impact. One-third (32.3%) met the gender-based ASE criteria for LV hypertrophy (LVH) with higher prevalence in both Maori cohorts (highest in the rural cohort). There were three significant predictors of LVH: rural Māori (p=0.0001); age (p<0.0001); and gender (p=0.0048).

CONCLUSION

Structural and functional heart abnormalities are more prevalent in Māori compared to non-Māori, and especially rural Māori. Early identification should lead to better management, ultimately improving life expectancy and quality of life.

Self-rated health, health-related behaviours and medical conditions of Maori and non-Maori in advanced age: LiLACS NZ

AIMS

To establish self-rated health, health-related behaviours and health conditions of Maori and non-Maori in advanced age.

METHOD

LiLACS NZ is a longitudinal study. A total of 421 Maori aged 80-90 years and 516 non-Maori aged 85 years living in the Bay of Plenty and Rotorua district were recruited at baseline (2010). Socioeconomic-demographic characteristics and health-related behaviours were established using interviewer administered questionnaire. Self-rated health was obtained from the SF-12. Medical conditions were established from a combination of self-report, review of general practitioner and hospital discharge records, and analyses of fasting blood samples.

RESULTS

61% Maori and 59% non-Maori rated their health from good to excellent. Eleven percent of Maori and 5% of non-Maori smoked; 23% Maori and 47% non-Maori had alcohol on at least 2 occasions per week. Physical activity was higher in Maori than non-Maori (p=0.035) and the relationship was attenuated when adjusted for age. More Maori (49%) than non-Maori (38%) were at high nutrition risk (p=0.005); and more non-Maori (73%) than Maori (59%) were driving (p<0.01). The three most common health conditions were hypertension (83%), eye diseases (58%) and coronary artery disease (44%). The health profile differed by gender and ethnicity. Overall, participants had a median of five health conditions.

CONCLUSION

Self-rated health is high in this sample considering the number of comorbidities. There are differences in health behaviours and health conditions between genders and by ethnicity in advanced age. The significance of health conditions in men and women, Maori and non-Maori in advanced age will be examined longitudinally.

Genetic polymorphism rs6922269 in the MTHFD1L gene is associated with survival and baseline active vitamin B12 levels in post-acute coronary syndromes patients

Background and Aims

The methylene-tetrahydrofolate dehydrogenase (NADP+ dependent) 1-like (MTHFD1L) gene is involved in mitochondrial tetrahydrofolate metabolism. Polymorphisms in MTHFD1L, including rs6922269, have been implicated in risk for coronary artery disease (CAD). We investigated the association between rs6922269 and known metabolic risk factors and survival in two independent cohorts of coronary heart disease patients.

Methods and Results

DNA and plasma from 1940 patients with acute coronary syndromes were collected a median of 32 days after index hospital admission (Coronary Disease Cohort Study, CDCS). Samples from a validation cohort of 842 patients post-myocardial infarction (PMI) were taken 24–96 hours after hospitalization. DNA samples were genotyped for rs6922269, using a TaqMan assay. Homocysteine and active vitamin B12 were measured by immunoassay in baseline CDCS plasma samples, but not PMI plasma. All cause mortality was documented over follow-up of 4.1 (CDCS) and 8.8 (PMI) years, respectively. rs6922269 genotype frequencies were AA n = 135, 7.0%; GA n = 785, 40.5% and GG n = 1020, 52.5% in the CDCS and similar in the PMI cohort. CDCS patients with AA genotype for rs6922269 had lower levels of co-variate adjusted baseline plasma active vitamin B12 (p = 0.017) and poorer survival than patients with GG or GA genotype (mortality: AA 19.6%, GA 12.0%, GG 11.6%; p = 0.007). In multivariate analysis, rs6922269 genotype predicted survival, independent of established covariate predictors (p = 0.03). However the association between genotype and survival was not validated in the PMI cohort.

Conclusion

MTHFD1L rs6922269 genotype is associated with active vitamin B12 levels at baseline and may be a marker of prognostic risk in patients with established coronary heart disease.

Hyperuricaemia and gout in New Zealand rural and urban Māori and non-Māori communities

BACKGROUND

There are few current data on the prevalence of hyperuricaemia and gout in New Zealand, particularly among the indigenous Māori population.

AIMS

To determine the prevalence of gout and hyperuricaemia in rural and urban Māori and non-Māori community samples and describe the treatment and comorbidities of participants with gout.

METHODS

Participants aged 20-64 years were recruited by random selection from the electoral roll. Māori samples were selected from among those identified as being of Māori descent on the roll and who self-identified as being of Māori ethnicity at interview. Personal medical history, blood pressure, anthropometrics, fasting lipids, glucose, HbA1c and urate were recorded.

RESULTS

There were 751 participants. Mean serum urate (SU) was 0.30 mmol/L (0.06-0.69 mmol/L). Māori had a significantly higher prevalence of hyperuricaemia (SU > 0.40 mmol/L) compared with non-Māori (17.0% vs 7.5%, P = 0.0003). A total of 57 participants had a history of gout, with a higher prevalence in Māori compared with non-Māori (10.3% vs 2.3%, P < 0.0001). Of the participants, 18/57 (31.6%) with gout were receiving urate-lowering therapy, but in 38.9%, SU was >0.36 mmol/L. Participants with gout were more likely to have metabolic syndrome, diabetes, cardiac disease or hypertension.

CONCLUSIONS

Gout and hyperuricaemia were more prevalent in Māori, and participants with gout were more likely to have comorbidities. There was not a higher overall adjusted cardiovascular disease risk in Māori participants with gout. Despite the high prevalence of gout, management remains suboptimal.

Predicting survival in heart failure: a risk score based on 39 372 patients from 30 studies

AIMS

Using a large international database from multiple cohort studies, the aim is to create a generalizable easily used risk score for mortality in patients with heart failure (HF).

METHODS AND RESULTS

The MAGGIC meta-analysis includes individual data on 39 372 patients with HF, both reduced and preserved left-ventricular ejection fraction (EF), from 30 cohort studies, six of which were clinical trials. 40.2% of patients died during a median follow-up of 2.5 years. Using multivariable piecewise Poisson regression methods with stepwise variable selection, a final model included 13 highly significant independent predictors of mortality in the following order of predictive strength: age, lower EF, NYHA class, serum creatinine, diabetes, not prescribed beta-blocker, lower systolic BP, lower body mass, time since diagnosis, current smoker, chronic obstructive pulmonary disease, male gender, and not prescribed ACE-inhibitor or angiotensin-receptor blockers. In preserved EF, age was more predictive and systolic BP was less predictive of mortality than in reduced EF. Conversion into an easy-to-use integer risk score identified a very marked gradient in risk, with 3-year mortality rates of 10 and 70% in the bottom quintile and top decile of risk, respectively.

CONCLUSION

In patients with HF of both reduced and preserved EF, the influences of readily available predictors of mortality can be quantified in an integer score accessible by an easy-to-use website www.heartfailurerisk.org. The score has the potential for widespread implementation in a clinical setting.

Genetic variation in the renin-angiotensin-aldosterone system is associated with cardiovascular risk factors and early mortality in established coronary heart disease

This study examined renin-angiotensin-aldosterone (RAAS) system gene variants for associations with cardiovascular risk factors and outcomes in coronary heart disease. Coronary disease patients (n=1186) were genotyped for 21 single-nucleotide polymorphisms (SNPs) within angiotensinogen (AGT), angiotensin-converting enzyme (ACE), angiotensin-II type-1 receptor (AGTR1) and aldosterone synthase (CYP11B2). Associations with all-cause mortality and cardiovascular readmissions were assessed over a median of 3.0 years. The AGT M235T 'T' allele was associated with a younger age of clinical coronary disease onset (P=0.006), and the AGT rs2478545 minor allele was associated with lower circulating natriuretic peptides (P=0.0001-P=0.001) and E/E(1) (P=0.018). Minor alleles of AGT SNPs rs1926723 and rs11122576 were associated with more frequent history of renal disease (P0.04) and type-2 diabetes (P0.02), higher body mass index (P0.02) and greater mortality (P0.007). AGT rs11568054 minor allele carriers had more frequent history of renal disease (P=0.04) and higher plasma creatinine (P=0.033). AGT rs6687360 minor allele carriers exhibited worse survival (P=0.02). ACE rs4267385 was associated with older clinical coronary disease onset (P=0.008) and hypertension (P=0.013) onset, increased plasma creatinine (P=0.01), yet greater mortality (P=0.044). Less history of hypertension was observed with the AGTR1 rs12685977 minor allele (P=0.039). Genetic variation within the RAAS was associated with cardiovascular risk factors and accordingly poorer survival.

Association between endothelin type A receptor haplotypes and mortality in coronary heart disease

AIMS

The endothelin type A receptor, encoded by EDNRA, mediates the effects of endothelin-1 to promote vasoconstriction, vascular cell growth, adhesion, fibrosis and thrombosis. We investigated the association between EDNRA haplotype and cardiovascular outcomes in patients with coronary artery disease.

METHODS

Coronary disease patients (n = 1007) were genotyped for the His323His (rs5333) variant and one tag SNP from each of the major EDNRA haplotype blocks (rs6537484, rs1568136, rs5335 and rs10003447). EDNRA haplotype associations with clinical history, natriuretic peptides cardiac function and cardiovascular outcomes were tested over a median 3.8 years.

RESULTS

Univariate analysis identified a 'low-risk' EDNRA haplotype associated with later age of Type 2 diabetes onset (p = 0.004) smaller BMI (p = 0.021), and reduced mortality (log rank p = 0.001). Cox proportional hazards analysis including established cardiovascular risk factors revealed an independent association between haplotype and mortality (p < 0.0001).

CONCLUSION

These data highlight the potential importance of the endothelin system, and in particular EDNRA in coronary disease.

A cohort study comparing cardiovascular risk factors in rural Maori, urban Maori and non-Maori communities in New Zealand

OBJECTIVES

To understand health disparities in cardiovascular disease (CVD) in the indigenous Māori of New Zealand, diagnosed and undiagnosed CVD risk factors were compared in rural Māori in an area remote from health services with urban Māori and non-Māori in a city well served with health services.

DESIGN

Prospective cohort study.

SETTING

Hauora Manawa is a cohort study of diagnosed and previously undiagnosed CVD, diabetes and risk factors, based on random selection from electoral rolls of the rural Wairoa District and Christchurch City, New Zealand.

PARTICIPANTS

Screening clinics were attended by 252 rural Māori, 243 urban Māori and 256 urban non-Māori, aged 20-64 years.

MAIN OUTCOME MEASURES

The study documented personal and family medical history, blood pressure, anthropometrics, fasting lipids, insulin, glucose, HbA1c and urate to identify risk factors in common and those that differ among the three communities.

RESULTS

Mean age (SD) was 45.7 (11.5) versus 42.6 (11.2) versus 43.6 (11.5) years in rural Māori, urban Māori and non-Māori, respectively. Age-adjusted rates of diagnosed cardiac disease were not significantly different across the cohorts (7.5% vs 5.8% vs 2.8%, p=0.073). However, rural Māori had significantly higher levels of type-2 diabetes (10.7% vs 3.7% vs 2.4%, p<0.001), diagnosed hypertension (25.0% vs 14.9% vs 10.7%, p<0.001), treated dyslipidaemia (15.7% vs 7.1% vs 2.8%, p<0.001), current smoking (42.8% vs 30.5% vs 15.2%, p<0.001) and age-adjusted body mass index (30.7 (7.3) vs 29.1 (6.4) vs 26.1 (4.5) kg/m(2), p<0.001). Similarly high rates of previously undocumented elevated blood pressure (22.2% vs 23.5% vs 17.6%, p=0.235) and high cholesterol (42.1% vs 54.3% vs 42.2%, p=0.008) were observed across all cohorts.

CONCLUSIONS

Supporting integrated rural healthcare to provide screening and management of CVD risk factors would reduce health disparities in this indigenous population.

Genomic Risk Variants at 1p13.3, 1q41, and 3q22.3 Are Associated With Subsequent Cardiovascular Outcomes in Healthy Controls and in Established Coronary Artery Disease

Background—

Genome-wide association studies have identified gene variants associated with coronary artery disease risk; however, whether they affect disease progression is largely unknown. This study investigated associations between polymorphisms at 1p13.3 (rs599839), 1q41 (rs17465637), and 3q22.3 (rs9818870) and cardiovascular outcomes in healthy volunteers and in patients with established heart disease.

Methods and Results—

Canterbury Healthy Volunteer study (HV) (n=1649), Coronary Disease Cohort Study (CDCS) (n=1797), and Post-Myocardial Infarction study (PMI) (n=906) participants (New Zealand), were genotyped for rs599839, rs9818870, and rs17465637. Associations between genotype and anthropometric characteristics, neurohormonal analysis, echocardiography, and clinical outcomes over medium-long-term follow-up (median HV, 5.9 years; CDCS, 3.7 years; PMI, 11.3 years) were tested. At 1p13.3, HV and CDCS participants carrying 1 or more rs599839 G allele had a lower prevalence of dyslipidemia ( P ≤0.005) or lower levels of low-density lipoprotein ( P =0.031) and total ( P =0.004) cholesterol and/or less history of myocardial infarction ( P ≤0.04) compared with AA participants. Moreover, CDCS and PMI AG/GG participants had better cardiac function as indicated by echocardiography ( P ≤0.026), and fewer CDCS AG/GG participants were readmitted for a non-ST-segment elevation MI ( P =0.012) during follow-up. The polymorphism at 1q41 (rs17465637) was associated with better cardiovascular outcomes in the HV ( P =0.028) and PMI ( P =0.008) cohorts, and 3q22.3 (rs9818870) was a predictor of death/admission in the HV cohort ( P =0.045).

Conclusions—

These data suggest that coronary artery disease genomic risk variants at 1p13.3 and 1q41 are associated with subsequent clinical outcome in heart patients and confirm rs9818870 at 3q22.3 as a predictor of cardiovascular risk in individuals free of overt heart disease.

Community screening for cardiovascular risk factors and levels of treatment in a rural Māori cohort

OBJECTIVES

To document levels of cardiovascular disease (CVD), diagnosed and undiagnosed risk factors and clinical management of CVD risk in rural Māori.

METHODS

Participants (aged 20-64 years), of Māori descent and self-report, were randomly sampled to be representative of age and gender profiles of the community. Screening clinics included health questionnaires, fasting blood samples, blood pressure and anthropometric measures. Data were obtained from participants' primary care physicians regarding prior diagnoses and current clinical management. New Zealand Cardiovascular Guidelines were used to identify new diagnoses at screening and Bestpractice electronic-decision support software used to estimate 5-year CVD risk.

RESULTS

Mean age of participants (n=252) was 45.7 ± 0.7, 8% reported a history of cardiac disease, 43% were current smokers, 22% had a healthy BMI, 30% were overweight and 48% obese. Hypertension was previously diagnosed in 25%; an additional 22% were hypertensive at screening. Dyslipidaemia was previously diagnosed in 14% and an additional 43% were dyslipidaemic at screening. Type-2 diabetes was previously diagnosed in 11%. Glycaemic control was achieved in only 21% of those with type-2 diabetes. Blood pressure and cholesterol were above recommended targets in more than half of those with diagnosed CVD risk factors.

CONCLUSIONS

High levels of diagnosed and undiagnosed CVD risk factors, especially hypertension, dyslipidaemia and diabetes were identified in this rural Māori community.

IMPLICATIONS

There is a need for opportunistic screening and intensified management of CVD risk factors in this indigenous population group.

KCNE5 polymorphism rs697829 is associated with QT interval and survival in acute coronary syndromes patients

INTRODUCTION

The KCNE family is a group of small transmembrane channel proteins involved in potassium ion (K(+)) conductance. The X-linked KCNE5 gene encodes a regulator of the K(+) current mediated by the potassium channel KCNQ1. Polymorphisms in KCNE5 have been associated with altered cardiac electrophysiological properties in human studies. We investigated associations of the common rs697829 polymorphism from KCNE5 with baseline characteristics, baseline electrocardiographic (ECG) measurements, and patient survival in a cohort of post-acute coronary syndromes (ACS) patients (the Coronary Disease Cohort Study cohort).

METHODS AND RESULTS

DNA samples (n = 1,740) were genotyped for rs697829 using a TaqMan assay. Baseline ECG data revealed corrected QT (QTc) interval was associated with rs697829 in male, but not female, patients, being extended in the G genotype group (A 416 ± 1.71; G 431 ± 4.25 ms, P = 0.002). Covariate-adjusted survival was poorest in G genotype patients in Cox proportional hazard modeling of mortality data of males (P(overall) = 0.020). Male patients with G genotype had a hazard ratio of 1.44 (1.11-2.33) for death when compared to the A genotype male patients (P = 0.048) after adjustment for age, baseline log-transformed N-terminal pro-B-type natriuretic peptide (NTproBNP), β-blocker and insulin treatment, QTc interval, history of myocardial infarction, and physical activity score.

CONCLUSION

This study suggests an association between rs697829, a common single nucleotide polymorphism (SNP) from KCNE5, and ECG measurements and survival in postacute ACS patients. Prolonged subclinical QT interval may be a marker of adverse outcome in this group of patients. 

Screening for left ventricular hypertrophy in patients with type 2 diabetes mellitus in the community

BACKGROUND

Left ventricular hypertrophy (LVH) is a strong predictor of cardiovascular disease and is common among patients with type 2 diabetes. However, no systematic screening for LVH is currently recommended for patients with type 2 diabetes. The purpose of this study was to determine whether NT-proBNP was superior to 12-lead electrocardiography (ECG) for detection of LVH in patients with type 2 diabetes.

METHODS

Prospective cross-sectional study comparing diagnostic accuracy of ECG and NT-proBNP for the detection of LVH among patients with type 2 diabetes. Inclusion criteria included having been diagnosed for > 5 years and/or on treatment for type 2 diabetes; patients with Stage 3/4 chronic kidney disease and known cardiovascular disease were excluded. ECG LVH was defined as either the Sokolow-Lyon or Cornell voltage criteria. NT-proBNP level was measured using the Roche Diagnostics Elecsys assay. Left ventricular mass was assessed from echocardiography. Receiver operating characteristic curve analysis was carried out and area under the curve (AUC) was calculated.

RESULTS

294 patients with type 2 diabetes were recruited, mean age 58 (SD 11) years, BP 134/81 ± 18/11 mmHg, HbA 1c 7.3 ± 1.5%. LVH was present in 164 patients (56%). In a logistic regression model age, gender, BMI and a history of hypertension were important determinants of LVH (p < 0.05). Only 5 patients with LVH were detected by either ECG voltage criteria. The AUC for NT-proBNP in detecting LVH was 0.68.

CONCLUSIONS

LVH was highly prevalent in asymptomatic patients with type 2 diabetes. ECG was an inadequate test to identify LVH and while NT-proBNP was superior to ECG it remained unsuitable for detecting LVH. Thus, there remains a need for a screening tool to detect LVH in primary care patients with type 2 diabetes to enhance risk stratification and management.

Association of genetic variation in the natriuretic peptide system with cardiovascular outcomes

Polymorphisms within individual natriuretic peptide genes have been associated with risk factors for cardiovascular disease, but their association with clinical outcomes was previously unknown. This study aimed to investigate the association between genetic variants in key genes of the natriuretic peptide system with cardiovascular outcomes in patients with coronary artery disease. Coronary disease patients (n=1810) were genotyped for polymorphisms within NPPA, NPPB, NPPC, NPR1 and NPR2. Clinical history, natriuretic peptide concentrations, echocardiography, all-cause mortality and cardiovascular hospital readmissions were recorded over a median 2.8 years. Minor alleles of NPPA rs5068, rs5065 and rs198358 were associated with less history of hypertension; minor alleles of NPPA rs5068 and rs198358 was also associated with higher circulating natriuretic peptide levels (p=0.003 to p=0.04). Minor alleles of NPPB rs198388, rs198389, and rs632793 were associated with higher circulating BNP and NT-proBNP (p=0.001 to p=0.03), and reduced E/E(1) (p=0.011), or LVESVI (p=0.001) and LVEDVI (p=0.004). Within NPPC, both rs11079028 and rs479651 were associated with higher NT-proBNP and CNP (p=0.01 to p=0.03), and rs479651 was associated with lower LVESVI (p=0.008) and LVEDVI (p=0.018). NPR2 rs10758325 was associated with smaller LVMI (p<0.02). A reduced rate of cardiovascular readmission was observed for minor alleles of NPPA rs5065 (p<0.0001), NPPB rs632793 (p<0.0001), rs198388 (p<0.0001), rs198389 (p<0.0001), and NPR2 rs10758325 (p<0.0001). There were no associations with all-cause mortality. In established cardiovascular disease, natriuretic peptide system polymorphisms were associated with natriuretic peptide levels, hypertension, echocardiographic indices and the incidence of hospital readmission for cardiovascular events.

How is the risk of undernutrition associated with cardiovascular disease among individuals of advanced age?

BACKGROUND

The oldest old (85+) are the fastest growing population segment in New Zealand. Cardiovascular disease (CVD) is the main cause of death and is associated with various risk factors including risk of undernutrition.

OBJECTIVES

To determine if there is an association between CVD and nutrition risk in advanced age.

SETTING

Three North Island locations (rural and urban areas) in New Zealand.

PARTICIPANTS

108 participants aged 85 years (75-79 for Maori).

MEASUREMENTS

Comprehensive health assessments were undertaken. Clinically manifest CVD was pre-defined and ascertained from interviews and hospitalisation records. Nutrition risk was assessed using a validated questionnaire-Seniors in the Community: Risk evaluation for eating and nutrition, Version II (SCREEN II).

RESULTS

72 participants (67%) had CVD (49% men); 52% of participants had a SCREEN II score < 50. Those with CVD had lower HDL level [median(IQR)] [1.4(0.7) vs. 1.6(0.6)] (p=0.041), and higher waist circumference [97.5(19.1) vs. 89.3(20.6)] (p=0.043) compared to those without CVD. Those with CVD were at no greater nutrition risk than those without CVD (SCREEN II score: [49(7) vs. 51(10)] (p=0.365). Using logistic regression controlling for confounders, SCREEN II scores trended towards an inverse association with CVD (p=0.10).

CONCLUSION

Two thirds of the study participants had CVD and half were at risk of undernutrition. Nutrition risk was mildly associated with CVD. This study provides further evidence that those in advanced age are at risk of undernutrition. Further research is needed to establish how the causes and consequences of CVD are related to nutrition risk.

Role of echocardiographic left ventricular mass and carotid intima-media thickness in the cardiovascular risk assessment of asymptomatic patients with type 2 diabetes mellitus

BACKGROUND

Standard cardiovascular (CV) risk assessment may underestimate risk in people with type 2 diabetes mellitus (T2DM). Cardiac and vascular imaging to detect subclinical disease may augment risk prediction. This study investigated the association between CV risk, left ventricular hypertrophy (LVH) and carotid intima-media thickness (CIMT) in patients with T2DM free of CV symptoms.

METHODS

People with T2DM without known CV disease were recruited from general practice. The 5-year risk of CV events was calculated using an adjusted Framingham equation and the prevalence of LVH and abnormal CIMT across bands of CV risk assessed. In those at intermediate risk, the number needed to scan (NNS) to reclassify one person to high risk was calculated across the group and compared in those above and below 55 years. The association between LV mass and CIMT was also assessed.

RESULTS

Mean age 57 years (SD11), 51% female. Median 5-year CV risk 14.3% (interquartile range 10.3, 19.5), 51% had LVH (American Society of Echocardiography criteria) and 31% an abnormal CIMT (age and sex criteria). In the 52% at intermediate risk, 37% had LVH and 36% an abnormal CIMT. The NNS was 1.7 using both imaging techniques, 2.7 using cardiac imaging alone or 2.8 using vascular imaging alone. Almost twice as many people >55 years had an abnormal CIMT than those <55 years.

CONCLUSIONS

Cardiac and vascular imaging to detect subclinical disease can be used to augment prediction of CV risk in people with T2DM at intermediate risk. The value of reclassifying risk is as yet unproven and requires outcome data from intervention studies.

A Common Variant at Chromosome 9P21.3 Is Associated With Age of Onset of Coronary Disease but Not Subsequent Mortality

Background—

Chromosome 9p21.3 (chr9p21.3) recently was identified by several genome-wide association studies as the genomic region most strongly associated with the risk of coronary artery disease. Within the chr9p21.3 locus, the single-nucleotide polymorphism rs1333049 has been demonstrated to be most strongly associated with susceptibility to developing coronary artery disease. However, the effect of rs1333049 on clinical outcomes in patients with established coronary disease has yet to be determined.

Methods and Results—

Coronary Disease Cohort Study (CDCS) (n=1054) and Post-Myocardial Infarction (PMI) (n=816) study participants were genotyped for rs1333049. Clinical history, circulating lipids, neurohormones, cardiac function, and discharge medications were documented. All-cause mortality and cardiovascular hospital readmissions were recorded over a median follow-up period of 4.0 years for the CDCS cohort and 9.1 years for the PMI cohort. The CDCS patients homozygous for the high-risk C allele had an age of onset 2 to 5 years earlier for coronary disease ( P =.005), angina ( P =.025), myocardial infarction ( P =.022), and percutaneous transluminal coronary angioplasty ( P =.009). Patients with the CC genotype also had higher levels of total cholesterol ( P =.033) and triglycerides ( P =.003). The PMI participants with the CC genotype were 3 years younger on admission ( P =.009). Cox proportional hazards analysis adjusting for established predictors of increased risk showed no significant association between rs1333049 genotype and mortality in either the CDCS ( P =.214) or the PMI ( P =.696) cohorts.

Conclusions—

The chr9p21.3 polymorphism rs1333049 was associated with an earlier age of disease onset in 2 coronary disease cohorts but not with poorer clinical outcome in either cohort.

Atrial fibrillation and the risk of death in patients with heart failure: a literature-based meta-analysis

BACKGROUND

Heart failure (HF) and atrial fibrillation (AF) are common, associated with significant morbidity and mortality, and frequently coexist. It is uncertain from published data if the presence of AF in patients with HF is associated with an incremental adverse outcome. The aim of this study was to combine the results of all studies investigating prognosis for patients with HF and AF compared with those in sinus rhythm (SR) to asses the mortality risk associated with this arrhythmia.

METHODS

Electronic databases were searched (Biological Abstracts, Current Contents, EMBASE, Medline, Medline In-progress, PubMed and Scopus), to 31 December 2006, using the key words congestive heart failure, heart failure, ventricular dysfunction, atrial fibrillation, atrial flutter, sinus rhythm, prognosis, outcome, death and hospitalization. Bibliographies of retrieved publications were hand searched. Studies were eligible if they included a HF population and if outcomes were reported by cardiac rhythm (AF or SR). Studies were reviewed by predetermined protocol (including quality assessment). Data were pooled using a random effects model.

RESULTS

Twenty studies were included (from 3380 initially identified) representing 32946 patients (10819 deaths). Nine randomized controlled trials (RCT) were included. The prevalence of AF was 15%, crude mortality rates were 46% (AF) and 33% (SR). The odds ratio for death was 1.33 (95% confidence interval (CI) 1.12-1.59) for AF compared with SR. Eleven observational studies were included. The prevalence of AF was 23%, crude mortality rates were 38% (AF) and 25% (SR). The odds ratio for death was 1.57 (95% CI 1.20-2.05) for AF compared with SR.

CONCLUSION

This meta-analysis demonstrates that AF is associated with worse outcomes for patients with HF compared with those with SR. Further research is required to determine whether the adverse outcome associated with AF is related to the arrhythmia itself, or to variables, such as HF severity, patient age and comorbidity.

A copper(II)-selective chelator ameliorates left-ventricular hypertrophy in type 2 diabetic patients: a randomised placebo-controlled study

AIMS/HYPOTHESIS

Cu(II)-selective chelation with trientine ameliorates cardiovascular and renal disease in a model of diabetes in rats. Here, we tested the hypothesis that Cu(II)-selective chelation might improve left ventricular hypertrophy (LVH) in type 2 diabetic patients.

METHODS

We performed a 12 month randomised placebo-controlled study of the effects of treatment with the Cu(II)-selective chelator trientine (triethylenetetramine dihydrochloride, 600 mg given orally twice daily) on LVH in diabetic patients (n = 15/group at baseline) in an outpatient setting wherein participants, caregivers and those assessing outcomes were blinded to group assignment. Using MRI, we measured left ventricular variables at baseline, and at months 6 and 12. The change from baseline in left ventricular mass indexed to body surface area (LVM(bsa)) was the primary endpoint variable.

RESULTS

Diabetic patients had LVH with preserved ejection fraction at baseline. Trientine treatment decreased LVM(bsa) by 5.0 +/- 7.2 g/m(2) (mean +/- SD) at month 6 (when 14 trientine-treated and 14 placebo-treated participants were analysed; p = 0.0056 compared with placebo) and by 10.6 +/- 7.6 g/m(2) at month 12 (when nine trientine-treated and 13 placebo-treated participants were analysed; p = 0.0088), whereas LVM(bsa) was unchanged by placebo treatment. In a multiple-regression model that explained ~75% of variation (R (2) = 0.748, p = 0.001), cumulative urinary Cu excretion over 12 months was positively associated with trientine-evoked decreases in LVM(bsa).

CONCLUSIONS/INTERPRETATION

Cu(II)-selective chelation merits further exploration as a potential pharmacotherapy for diabetic heart disease.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry ACTRN 12609000053224 FUNDING: The Endocore Research Trust; Lottery Health New Zealand; the Maurice and Phyllis Paykel Trust; the Foundation of Research, Science and Technology (New Zealand); the Health Research Council of New Zealand; the Ministry of Education (New Zealand) through the Maurice Wilkins Centre for Molecular Biodiscovery; and the Protemix Corporation.