aims: The Family Heart Study (FHS) aims to identify genetic risk factors associated with strong personal and familial premature cardiovascular disease (CVD) in Māori and non-Māori families in Aotearoa New Zealand, and to compare this high-risk cohort with heart-healthy controls. methods: Participants were recruited from Christchurch Hospital cardiology wards and Christchurch Heart Institute research cohorts. Clinical data included blood pressure, anthropometry and questionnaires on medical history and lifestyle. Blood samples were collected for genetic and biomarker analyses. Genotyping and deoxyribonucleic acid (DNA) methylation profiling were performed using commercial cardiovascular arrays. results: To date, 472 individuals have been screened, with 28 meeting strict inclusion criteria for documented personal and family history of early-onset CVD. The cohort includes 25 NZ European and three Māori participants, with a mean CVD onset age of 46.6 years. Most participants (75%) had a history of myocardial infarction, and the median number of affected first-degree relatives was two. After quality control, 185,514 single-nucleotide polymorphisms and 454,608 DNA methylation sites were retained for downstream analyses. conclusion: The FHS represents a rare cohort with strong inherited susceptibility to premature CVD. Ongoing recruitment will support investigation of genetic and epigenetic contributors to early-onset CVD in New Zealand.

INTRODUCTION:The prognostic value of cardiac troponins in revascularized patients with myocardial infarction (MI) is uncertain. This study examined the relationship between peak troponin levels and adverse outcomes in a revascularized cohort from the Multi-Ethnic New Zealand Study of Acute Coronary Syndromes (MENZACS). METHODS:MENZACS enrolled patients with a first-time acute coronary syndrome from 2015 to 2019. Peak high sensitivity troponin was standardized by dividing the observed peak troponin by the upper limit of normal. The primary outcome was a composite of all-cause death or cardiovascular readmission, determined through national datasets. Troponin's relationship with outcomes was analysed using penalized spline Cox regression. RESULTS:Among 1,645 revascularized patients (81% male, mean age 61, 74% European, 14% Māori, 5% Pacific, 5% Indian, 3% Other; 46% ST-elevation MI (STEMI), 54% non-STEMI), higher peak troponin was associated with male sex, STEMI, current smoking, and elevated N-terminal pro-B-type natriuretic peptide levels. Over a median of 4.9 years, 402 (24%) people experienced the primary outcome. Peak troponin levels were not significantly associated with this outcome. CONCLUSION:In this revascularized cohort surviving a first-time MI, the magnitude of peak troponin elevation was not associated with all-cause death or cardiovascular readmission.

BACKGROUND AND AIMS:Lipoprotein(a) (Lp[a]) is an established predictor of cardiovascular risk but associations with secondary events are less certain, and data on understudied ethnic groups are scarce. This study aimed to assess the association between Lp(a) and secondary events and explore variation in Lp(a) levels by ethnicity in first-time acute coronary syndrome (ACS) patients, to inform future risk prediction models. METHODS:The Multi-Ethnic New Zealand Study of Acute Coronary Syndromes (MENZACS) is a longitudinal multi-centre cohort study of 1900 patients enrolled during their ACS admission. Baseline plasma Lp(a) concentrations were measured using an isoform-insensitive assay measured in nmol/L. The primary outcome was a composite of all-cause mortality or cardiovascular readmission, ascertained through national health datasets. Cox regression models were used to assess the association between Lp(a) levels and outcomes, adjusted for clinical risk factors. RESULTS:The mean age was 61 years, 20 % were female, and 73 % were European, 14 % Māori, 5 % Pacific peoples, 4 % Indian and 3 % other ethnicities. Of 1890 alive at discharge, 493 (26 %) experienced the primary outcome over a median follow-up of 4.9 years. Higher Lp(a) levels were associated with increased risk of secondary events. Compared to the lowest quartile (≤7 nmol/L), the adjusted hazard ratio for the highest quartile (>92 nmol/L) was 1.46 (95 %CI 1.12-1.89, p = 0.004). In this ACS cohort, Lp(a) concentrations varied by ethnicity, being highest amongst Indian participants (median 27 nmol/L) and lowest amongst Māori participants (median 12 nmol/L). CONCLUSIONS:Elevated Lp(a) concentrations are associated with secondary events following ACS. Further research is needed to define optimal thresholds for increased risk and explore ethnic-specific implications for secondary prevention.

Epigenetic research, particularly DNA methylation (DNAm), holds significant potential for improving cardiovascular disease (CVD) risk prediction, yet its application must be guided by ethical and culturally responsive considerations. This paper examines the integration of a values-based framework to ensure the culturally safe conduct of DNAm research within the Multi-Ethnic New Zealand Study of Acute Coronary Syndromes (MENZACS) cohort. Grounded in Te Tiriti o Waitangi principles and kaupapa Māori methodologies, this study emphasises equity, social accountability, and indigenous data sovereignty. This study was not designed as a discovery epigenome wide analysis, but rather performed, as an exemplar, a SWOT analysis that identified both the potential of DNAm markers, such as cg05575921 in AHRR for smoking exposure assessment, and key risks, including genetic confounding, population-specific variation, and the potential for individual and transgenerational stigma. Findings underscore the importance of ensuring multi-ethnic validation of DNAm markers to prevent exacerbation of health inequities. This paper advocates for the adoption of ethical, culturally attuned research frameworks in epigenetics to enhance equitable health outcomes and support Māori health advancement.

Abstract Background Pacific Peoples living in Aotearoa New Zealand (NZ) have higher rates of type 2 diabetes (T2D) and have benefited less from improvements in cardiovascular health outcomes when compared with other populations in NZ. DNA methylation markers of T2D have been identified in non-Pacific populations and could be used to monitor the cumulative effects of T2D on cardiovascular disease risk. However, no study has yet investigated the relationships between T2D and DNA methylation in Pacific Peoples living in NZ. Purpose This study aimed to quantify the relationship between DNA methylation and T2D in two cohorts of Pacific Peoples living in NZ. Methods Whole-blood DNA methylation at over 850,000 loci was measured on Illumina MethylationEPIC arrays in 288 Pacific participants from the Pasifika Heart Study (PHS, n=191), a community cohort, and the Multi-Ethnic NZ Study of Acute Coronary Syndromes (MENZACS, n=97), a cohort of patients with acute coronary syndromes. In the PHS, the median age was 41 years, and 98 (51%) participants were female. In MENZACS, the median age was 53 years, and 18 (19%) participants were female. In both cohorts, T2D cases were defined by either previous diagnosis (n=58) or had an HbA1c measurement >58 mmol/mol (n=7). We compared 65 participants with T2D and 223 participants without T2D of Samoan (n=116), Tongan (n=66), Fijian (n=61), Cook Island Māori (n=22), Niuean (n=9), or of Other/Multiple Pacific (n=14) ethnicity in a meta epigenome-wide association study (EWAS). EWAS comparisons were adjusted for age, sex, and imputed blood cell composition. We compared the difference in means at differentially methylated loci between the European and Pacific MENZACS participants using a two-sample z statistic. For the 525 European participants, 85 had T2D, the median age was 57 years, and 149 (28%) were female. Results One locus cg19693031, in the thioredoxin interacting protein (TXNIP) gene, exhibited differential methylation between those with T2D and those without in the meta EWAS (false discovery rate =6.9x10-9). In the PHS we observed a mean reduction in cg19693031 methylation of 7.0% (95% CI, 5.0, 8.9) between those with T2D and those without. Similarly in the MENZACS Pacific participants we observed a mean reduction in cg19693031 methylation of 10.9% (95% CI, 7.6, 12.4) between those with T2D and those without. The MENZACS European participants with T2D had a mean reduction in cg19693031 methylation of 6.5% (95% CI, 5.3, 7.7, p<0.001) compared to those without T2D. The difference in means in T2D cases and controls between MENZACS Pacific and European participants was non-significant (p =0.08). Conclusion DNA methylation at cg19693031 is associated with T2D in Pacific Peoples living in NZ and may be a sensitive marker of T2D in Pacific Peoples with acute coronary syndromes. DNA methylation at this locus may provide valuable information on the relationship between T2D and cardiovascular disease.Miami plot of Pacific T2D EWAST2D methylation by population in MENZACS

Aims Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF), components of the vascular endothelial growth factor (VEGF) system, play key roles in angiogenesis. Reports of elevated plasma levels of sFlt-1 and PlGF in coronary heart disease and heart failure (HF) led us to investigate their utility, and VEGF system gene single nucleotide polymorphisms (SNPs), as prognostic biomarkers in HF. Methods and results ELISA assays for sFlt-1, PlGF and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were performed on baseline plasma samples from the PEOPLE cohort (n = 890), a study of outcomes among patients after an episode of acute decompensated HF. Eight SNPs potentially associated with sFlt-1 or PlGF levels were genotyped. sFlt-1 and PlGF were assayed in 201 subjects from the Canterbury Healthy Volunteers Study (CHVS) matched to PEOPLE participants. All-cause death was the major endpoint for clinical outcome considered. In PEOPLE participants, mean plasma levels for both sFlt-1 (125 +/- 2.01 pg/ml) and PlGF (17.5 +/- 0.21 pg/ml) were higher (both p < 0.044) than in the CHVS cohort (81.2 +/- 1.31 pg/ml and 15.5 +/- 0.32 pg/ml, respectively). sFlt-1 was higher in HF with reduced ejection fraction compared to HF with preserved ejection fraction (p = 0.005). The PGF gene SNP rs2268616 was univariately associated with death (p = 0.016), and was also associated with PlGF levels, as was rs2268614 genotype. Cox proportional hazards modelling (n = 695, 246 deaths) showed plasma sFlt-1, but not PlGF, predicted survival (hazard ratio 6.44, 95% confidence interval 2.57-16.1; p < 0.001) in PEOPLE, independent of age, NT-proBNP, ischaemic aetiology, diabetic status and beta-blocker therapy. Conclusions Plasma sFlt-1 concentrations have potential as an independent predictor of survival and may be complementary to established prognostic biomarkers in HF.

Abstract Background Approximately 10% of people develop heart failure (HF) within 5 years after an acute coronary event. Once ischaemic damage has occurred, the heart undergoes remodeling, which can lead to subclinical dysfunction and HF. However, remodeling varies considerably between patients and is difficult to predict. Purpose To assess whether adding genetic information to clinical factors improves the accuracy of predicting incident non-fatal/fatal HF within 5 years in people with coronary artery disease (CAD). Methods In the UK Biobank (UKB) [1], we developed a clinical risk model (predictors age, sex, ethnicity, body mass index, social deprivation, smoking, personal medical history, time since most recent CAD admission, lipids, HbA1C, creatinine, medications). Separately, we performed a genome-wide association meta-analysis of 13,360 (6,315 + 7,045) cases and 58,126 (37,245 + 20,881) non-cases from the UKB and deCODE [2] cohorts, relating common genetic variants to non-fatal/fatal HF or cardiomyopathy in people with CAD. For the current analysis of the UKB cohort, we derived a polygenic risk score using summary statistics from deCODE alone. We then compared risk estimates and assessed reclassification of 5-year risk using the clinical risk model with and without polygenic risk score, in UKB. Risk groups were <5%, 5-9.9%, 10-14.9%, ≥15%. Results Among people with CAD in the 5 years prior to assessment in UKB (n=8,880, mean age 61y, 27% women) or deCODE (n=10,113, mean age 66y, 34% women), 377 (4%) and 915 (9%) developed non-fatal/fatal HF over 5 years follow-up, respectively. In the UKB cohort, median 5-year risk with the clinical model was 3.2% (IQR 2-5.4%, C-statistic 0.72, 95% CI 0.70–0.74, Table 1) and plots of predicted versus observed risk showed very good calibration across deciles. The polygenic risk score was predictive of non-fatal/fatal HF in the UKB (hazard ratio 1.03, 95% CI 1.00 to 1.05 per standard deviation) with significance decreasing after adjusting for the prognostic index of the clinical risk model (hazard ratio 1.02, 95% CI 0.99 to 1.05 per standard deviation). Median 5-year risk by the clinical+polygenic model was 3.0% (IQR 1.9-5.0%). Net reclassification with the addition of the polygenic score improved accuracy of risk prediction for 3.6% of non-cases but deteriorated accuracy of risk prediction for 6% of cases. Overall net reclassification was deterioration of -0.025. Conclusion Our data suggest that common genetic variants may be associated with progression from CAD to HF, but that adding genetic data did not improve the accuracy of predicting progression from CAD to HF beyond established clinical predictors in the UKB cohort. Confirmation of these findings in deCODE and other large cohorts is warranted.

Background Individuals born very low birthweight (VLBW) are at increased risk of impaired cardiovascular and respiratory function in adulthood. To identify markers to predict future risk for VLBW individuals, we analyzed DNA methylation at birth and at 28 years in the New Zealand (NZ) VLBW cohort (all infants born < 1500 g in NZ in 1986) compared with age-matched, normal birthweight controls. Associations between neonatal methylation and cardiac structure and function (echocardiography), vascular function and respiratory outcomes at age 28 years were documented. Results Genomic DNA from archived newborn heel-prick blood ( n = 109 VLBW, 51 controls) and from peripheral blood at ~ 28 years ( n = 215 VLBW, 96 controls) was analyzed on Illumina Infinium MethylationEPIC 850 K arrays. Following quality assurance and normalization, methylation levels were compared between VLBW cases and controls at both ages by linear regression, with genome-wide significance set to p < 0.05 adjusted for false discovery rate (FDR, Benjamini-Hochberg). In neonates, methylation at over 16,400 CpG methylation sites differed between VLBW cases and controls and the canonical pathway most enriched for these CpGs was Cardiac Hypertrophy Signaling ( p = 3.44E −11 ). The top 20 CpGs that differed most between VLBW cases and controls featured clusters in ARID3A , SPATA33 , and PLCH1 and these 3 genes, along with MCF2L , TRBJ2 -1 and SRC , led the list of 15,000 differentially methylated regions (DMRs) reaching FDR-adj significance. Fifteen of the 20 top CpGs in the neonate EWAS showed associations between methylation at birth and adult cardiovascular traits (particularly LnRHI). In 28-year-old adults, twelve CpGs differed between VLBW cases and controls at FDR-adjusted significance, including hypermethylation in EBF4 (four CpGs), CFI and UNC119B and hypomethylation at three CpGs in HIF3A and one in KCNQ1 . DNA methylation GrimAge scores at 28 years were significantly greater in VLBW cases versus controls and weakly associated with cardiovascular traits. Four CpGs were identified where methylation differed between VLBW cases and controls in both neonates and adults, three reversing directions with age (two CpGs in EBF4, one in SNAI1 were hypomethylated in neonates, hypermethylated in adults). Of these, cg16426670 in EBF4 at birth showed associations with several cardiovascular traits in adults. Conclusions These findings suggest that methylation patterns in VLBW neonates may be informative about future adult cardiovascular and respiratory outcomes and have value in guiding early preventative care to improve adult health.

The prognostic value of cardiac troponin following myocardial infarction (MI) is well documented; however, the benefit in a predominantly revascularised cohort is less certain. This study reported the prognostic role of peak cardiac troponin in the Multi-Ethnic New Zealand Study of Acute Coronary Syndromes (MENZACS).

Objective The Multi-Ethnic New Zealand Study of Acute Coronary Syndromes (MENZACS) was established to investigate the drivers of secondary events after first-time acute coronary syndrome (ACS), including addressing inequitable outcomes by ethnicity. Herein, the first clinical outcomes and prognostic modelling approach are reported. Methods First, in 28 176 New Zealanders with first-time ACS from a national registry, a clinical summary score for predicting 1-year death/cardiovascular readmission was created using Cox regression of 20 clinical variables. This score was then calculated in the 2015 participant MENZACS study to represent clinical risk. In MENZACS, Cox regression was used to assess N-terminal pro-B-type natriuretic peptide (NT-proBNP) as a prognostic marker for death/cardiovascular readmission in four models, adjusting for (1) age and sex; (2) age, sex, ethnicity; (3) clinical summary score; (4) clinical summary score and ethnicity. Results Of the 2015 MENZACS participants (mean age 61 years, 79% male, 73% European, 14% Māori, 5% Pacific people), 2003 were alive at discharge. Of the 2003, 416 (20.8%) experienced all-cause death/cardiovascular readmission over a median of 3.5 years. In a simple model, age, male sex, Māori ethnicity and NT-proBNP levels were significant predictors of outcome. After adjustment for the clinical summary score, which includes age and sex, NT-proBNP and ethnicity were no longer statistically significant: log2(NT-proBNP) hazard ratio (HR) 1.03, 95% confidence interval (95% CI) 0.98 to 1.08, p=0.305; Māori ethnicity HR 1.26, 95% CI 0.97 to 1.62, p=0.084. Conclusions In 2015 patients with first-time ACS, recurrent events were common (20.8%). Increasing NT-proBNP levels and Māori ethnicity were predictors of death/cardiovascular readmission, but not after adjustment for the 20 clinical risk factors represented by the clinical summary score. Trial registration number ACTRN12615000676516.

Mass spectrometry is a powerful technique for investigating renal pathologies and identifying biomarkers, and efficient protein extraction from kidney tissue is essential for bottom-up proteomic analyses. Detergent-based strategies aid cell lysis and protein solubilization but are poorly compatible with downstream protein digestion and liquid chromatography-coupled mass spectrometry, requiring additional purification and buffer-exchange steps. This study compares two well-established detergent-based methods for protein extraction (in-solution sodium deoxycholate (SDC); suspension trapping (S-Trap)) with the recently developed sample preparation by easy extraction and digestion (SPEED) method, which uses strong acid for denaturation. We compared the quantitative performance of each method using label-free mass spectrometry in both sheep kidney cortical tissue and plasma. In kidney tissue, SPEED quantified the most unique proteins (SPEED 1250; S-Trap 1202; SDC 1197). In plasma, S-Trap produced the most unique protein quantifications (S-Trap 150; SDC 148; SPEED 137). Protein quantifications were reproducible across biological replicates in both tissue (R2 = 0.85–0.90) and plasma (SPEED R2 = 0.84; SDC R2 = 0.76, S-Trap R2 = 0.65). Our data suggest SPEED as the optimal method for proteomic preparation in kidney tissue and S-Trap or SPEED as the optimal method for plasma, depending on whether a higher number of protein quantifications or greater reproducibility is desired.

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.

One-quarter of patients with acute decompensated heart failure (ADHF) experience acute kidney injury (AKI)—an abrupt reduction or loss of kidney function associated with increased long-term mortality. There is a critical need to identify early and real-time markers of AKI in ADHF; however, to date, no protein biomarkers have exhibited sufficient diagnostic or prognostic performance for widespread clinical uptake. We aimed to identify novel protein biomarkers of AKI associated with ADHF by quantifying changes in protein abundance in the kidneys that occur during ADHF development and recovery in an ovine model. Relative quantitative protein profiling was performed using sequential window acquisition of all theoretical fragment ion spectra–mass spectrometry (SWATH–MS) in kidney cortices from control sheep (n = 5), sheep with established rapid-pacing-induced ADHF (n = 8), and sheep after ~4 weeks recovery from ADHF (n = 7). Of the 790 proteins quantified, we identified 17 candidate kidney injury markers in ADHF, 1 potential kidney marker of ADHF recovery, and 2 potential markers of long-term renal impairment (differential abundance between groups of 1.2–2.6-fold, adjusted p < 0.05). Among these 20 candidate protein markers of kidney injury were 6 candidates supported by existing evidence and 14 novel candidates not previously implicated in AKI. Proteins of differential abundance were enriched in pro-inflammatory signalling pathways: glycoprotein VI (activated during ADHF development; adjusted p < 0.01) and acute phase response (repressed during recovery from ADHF; adjusted p < 0.01). New biomarkers for the early detection of AKI in ADHF may help us to evaluate effective treatment strategies to prevent mortality and improve outcomes for patients.

Hydrogen sulfide (H2S) and substance P (SP) are known from animal models and in vitro studies as proinflammatory mediators. In this study, peripheral blood concentrations of H2S and SP were measured in patients with Escherichia coli or Klebsiella pneumoniae bacteraemia. Fifty patients were recruited from general wards at Christchurch Hospital, during 2020–2021. Samples from age- and sex-matched healthy subjects previously recruited as controls for studies of cardiovascular disease were used as controls. The concentrations of H2S were higher than controls on day 0, day 1, and day 2, and SP was higher than controls on all 4 days. The concentrations of H2S were highest on day 0, whereas SP concentrations were higher on day 2 than other days. Interleukin-6 and C-reactive protein were significantly higher on day 0 and day 1, respectively. The concentrations of H2S and SP did not differ between 15 non-septic (SIRS 0-1) and the 35 septic subjects (SIRS ≥ 2). Substance P concentrations were higher in subjects with abdominal infection than urinary tract infections on day 0 (p = 0.0002) and day 1 (p = 0.0091). In conclusion, the peak H2S concentrations precede the SP peak in patients with Gram-negative bacteraemia, but this response varies with the site of infection.