Association of Age, Sex, Body Size and Ethnicity with Electrocardiographic Values in Community-based Older Asian Adults.

BACKGROUND: Existing electrocardiographic (ECG) reference values were derived in middle-aged Caucasian adults. We aimed to assess the association of age, sex, body size and ethnicity on ECG parameters in a multi-ethnic Asian population. METHODS: Resting 12-lead ECG and anthropometric measurements were performed in a community-based cohort of 3777 older Asians (age 64.7±9.1 years, 1467 men, 88.8% Chinese, 7.7% Malay, 3.5% Indian, body mass index [BMI] 24.0±3.9kg/m(2)). RESULTS: Men had longer PR interval, wider QRS, shorter QTc interval and taller SV3. In both sexes, older age was associated with longer PR interval, wider QRS, larger R aVL and more leftward QRS axis, while higher BMI was associated with longer PR interval, wider QRS, larger RaVL and more negative QRS axis. There were significant inter-ethnic differences in QRS duration among men, as well as in PR and QTc intervals among women (all adjusted p<0.05). Findings were similar in a healthy subset of 1158 adults (age 61.2±9.1 years, 365 men) without cardiovascular risk factors. CONCLUSIONS: These first community-based ECG data in multi-ethnic older Asians highlight the independent effects of age, sex, body size and ethnicity on ECG parameters.

The influence of atrial fibrillation on the levels of NT-proBNP versus GDF-15 in patients with heart failure.

BACKGROUND: In heart failure (HF), levels of NT-proBNP are influenced by the presence of concomitant atrial fibrillation (AF), making it difficult to distinguish between HF versus AF in patients with raised NT-proBNP. It is unknown whether levels of GDF-15 are also influenced by AF in patients with HF. In this study we compared the plasma levels of NT-proBNP versus GDF-15 in patients with HF in AF versus sinus rhythm (SR). METHODS: In a post hoc analysis of the index cohort of BIOSTAT-CHF (n = 2516), we studied patients with HF categorized into three groups: (1) AF at baseline (n = 733), (2) SR at baseline with a history of AF (n = 183), and (3) SR at baseline and no history of AF (n = 1025). The findings were validated in the validation cohort of BIOSTAT-CHF (n = 1738). RESULTS: Plasma NT-proBNP levels of patients who had AF at baseline were higher than those of patients in SR (both with and without a history of AF), even after multivariable adjustment (3417 [25th-75th percentile 1897-6486] versus 1788 [682-3870], adjusted p < 0.001, versus 2231 pg/mL [902-5270], adjusted p < 0.001). In contrast, after adjusting for clinical confounders, the levels of GDF-15 were comparable between the three groups (3179 [2062-5253] versus 2545 [1686-4337], adjusted p = 0.36, versus 2294 [1471-3855] pg/mL, adjusted p = 0.08). Similar patterns of both NT-proBNP and GDF-15 were found in the validation cohort. CONCLUSION: These data show that in patients with HF, NT-proBNP is significantly influenced by underlying AF at time of measurement and not by previous episodes of AF, whereas the levels of GDF-15 are not influenced by the presence of AF. Therefore, GDF-15 might have additive value combined with NT-proBNP in the assessment of patients with HF and concomitant AF.

Combining Circulating MicroRNA and NT-proBNP to Detect and Categorize Heart Failure Subtypes.

BACKGROUND: Clinicians need improved tools to better identify nonacute heart failure with preserved ejection fraction (HFpEF). OBJECTIVES: The purpose of this study was to derive and validate circulating microRNA signatures for nonacute heart failure (HF). METHODS: Discovery and validation cohorts (N = 1,710), comprised 903 HF and 807 non-HF patients from Singapore and New Zealand (NZ). MicroRNA biomarker panel discovery in a Singapore cohort (n = 546) was independently validated in a second Singapore cohort (Validation 1; n = 448) and a NZ cohort (Validation 2; n = 716). RESULTS: In discovery, an 8-microRNA panel identified HF with an area under the curve (AUC) 0.96, specificity 0.88, and accuracy 0.89. Corresponding metrics were 0.88, 0.66, and 0.77 in Validation 1, and 0.87, 0.58, and 0.74 in Validation 2. Combining microRNA panels with N-terminal pro-B-type natriuretic peptide (NT-proBNP) clearly improved specificity and accuracy from AUC 0.96, specificity 0.91, and accuracy 0.90 for NT-proBNP alone to corresponding metrics of 0.99, 0.99, and 0.93 in the discovery and 0.97, 0.96, and 0.93 in Validation 1. The 8-microRNA discovery panel distinguished HFpEF from HF with reduced ejection fraction with AUC 0.81, specificity 0.66, and accuracy 0.72. Corresponding metrics were 0.65, 0.41, and 0.56 in Validation 1 and 0.65, 0.41, and 0.62 in Validation 2. For phenotype categorization, combined markers achieved AUC 0.87, specificity 0.75, and accuracy 0.77 in the discovery with corresponding metrics of 0.74, 0.59, and 0.67 in Validation 1 and 0.72, 0.52, and 0.68 in Validation 2, as compared with NT-proBNP alone of AUC 0.71, specificity 0.46, and accuracy 0.62 in the discovery; with corresponding metrics of 0.72, 0.44, and 0.57 in Validation 1 and 0.69, 0.48, and 0.66 in Validation 2. Accordingly, false negative (FN) (81% Singapore and all NZ FN cases were HFpEF) as classified by a guideline-endorsed NT-proBNP ruleout threshold, were correctly reclassified by the 8-microRNA panel in the majority (72% and 88% of FN in Singapore and NZ, respectively) of cases. CONCLUSIONS: Multi-microRNA panels in combination with NT-proBNP are highly discriminatory and improved specificity and accuracy in identifying nonacute HF. These findings suggest potential utility in the identification of nonacute HF, where clinical assessment, imaging, and NT-proBNP may not be definitive, especially in HFpEF.

Growth differentiation factor 15 in heart failure with preserved vs. reduced ejection fraction.

AIM: Growth differentiation factor 15 (GDF15) is a cytokine highly expressed in states of inflammatory stress. We aimed to study the clinical correlates and prognostic significance of plasma GDF15 in heart failure with preserved ejection fraction (HFpEF) vs. reduced ejection fraction(HFrEF), compared with N-terminal pro-brain natriuretic peptide (NT-proBNP), an indicator of haemodynamic wall stress. METHODS: Plasma GDF15 and NT-proBNP were prospectively measured in 916 consecutive patients with HFrEF (EF <50%; n = 730) and HFpEF (EF ≥50%; n = 186), and measured again at 6 months in 488 patients. Patients were followed up for a composite outcome of death or first HF rehospitalization. RESULTS: Median GDF15baseline values were similarly elevated in HFpEF [2862 (1812 represent the 25th percentile and 4176 represent the 75th percentile) ng/L] and HFrEF [2517 (1555, 4030) ng/L] (P = 0.184), whereas NT-proBNP was significantly lower in HFpEF than HFrEF (1119 ng/L vs. 2335 ng/L, P < 0.001). Independent correlates of GDF15baseline were age, systolic blood pressure, New York Heart Association (NYHA) class, diabetes, atrial fibrillation, sodium, haemoglobin, creatinine, diuretic therapy, high sensitivity troponin T (hsTnT) and NT-proBNP (all P < 0.05). During a median follow-up of 23 months, there were 379 events (307 HFrEF, 72 HFpEF). GDF15 remained a significant independent predictor for composite outcome even after adjusting for important clinical predictors including hsTnT and NT-proBNP (adjusted hazard ratio 1.76 per 1 Ln U, 95% confidence interval 1.39-2.21; P < 0.001), regardless of HF group (Pinteraction = 0.275). GDF15baseline provided incremental prognostic value when added to clinical predictors, hsTnT and NT-proBNP (area under receiver operating characteristic curve increased from 0.720 to 0.740, P < 0.019), with a net reclassification improvement of 0.183 (P = 0.004). Patients with ≥20% GDF156months increase had higher risk for composite outcome (adjusted hazard ratio 1.68, 95% confidence interval 1.15-2.45; P = 0.007) compared with those with GDF156months within ± 20% of baseline. CONCLUSIONS: The similarly elevated levels and independent prognostic utility of GDF15 in HFrEF and HFpEF suggest that beyond haemodynamic stress (NT-proBNP), inflammatory injury (GDF15) may play an important role in both HF syndromes.

Electrocardiographic Criteria for Left Ventricular Hypertrophy in Asians Differs from Criteria Derived from Western Populations--Community-based Data from an Asian Population.

INTRODUCTION: Electrocardiographic (ECG) criteria for left ventricular hypertrophy (LVH), such as the Cornell and Sokolow-Lyon voltage criteria were derived from Western populations. However, their utility and accuracy for diagnosing echocardiographic LVH in Asian populations is unclear. The objective of this study was to assess the accuracy of ECG criteria for LVH in Asians and to determine if alternative gender-specific ECG cut-offs may improve its diagnostic accuracy. MATERIALS AND METHODS: ECG and echocardiographic assessments were performed on 668 community-dwelling Asian adults (50.9% women; 57 ± 10 years) in Singapore. The accuracy of ECG voltage criteria was compared to echocardiographic LVH criteria based on the American Society of Echocardiography guidelines, and Asian ethnicity and gender-specific partition values. RESULTS: Echocardiographic LVH was present in 93 (13.6%) adults. Cornell criteria had low sensitivity (5.5%) and high specificity (98.9%) for diagnosing LVH. Modified gender specific cut-offs (18 mm in women, 22 mm in men) improved sensitivity (8.8% to 17.5%, 0% to 14.7%, respectively) whilst preserving specificity (98.2% to 94.2%, 100% to 95.8%). Similarly, Sokolow-Lyon criteria had poor sensitivity (7.7%) and high specificity (96.1%) for diagnosing LVH. Lowering the cut-off value from 35 mm to 31 mm improved the sensitivity in women from 3.5% to 14% while preserving specificity at 94.2%. A cut-off of 36 mm was optimal in men (sensitivity of 14.7%, specificity of 95.5%). CONCLUSION: Current ECG criteria for LVH derived in Western cohorts have limited sensitivity in Asian populations. Our data suggests that ethnicity- and gender-specific ECG criteria may be needed.

Circulating microRNAs in heart failure with reduced and preserved left ventricular ejection fraction.

AIM: The potential diagnostic utility of circulating microRNAs in heart failure (HF) or in distinguishing HF with reduced vs. preserved left ventricular ejection fraction (HFREF and HFPEF, respectively) is unclear. We sought to identify microRNAs suitable for diagnosis of HF and for distinguishing both HFREF and HFPEF from non-HF controls and HFREF from HFPEF. METHODS AND RESULTS: MicroRNA profiling performed on whole blood and corresponding plasma samples of 28 controls, 39 HFREF and 19 HFPEF identified 344 microRNAs to be dysregulated among the three groups. Further analysis using an independent cohort of 30 controls, 30 HFREF and 30 HFPEF, presented 12 microRNAs with diagnostic potential for one or both HF phenotypes. Of these, miR-1233, -183-3p, -190a, -193b-3p, -193b-5p, -211-5p, -494, and -671-5p distinguished HF from controls. Altered levels of miR-125a-5p, -183-3p, -193b-3p, -211-5p, -494, -638, and -671-5p were found in HFREF while levels of miR-1233, -183-3p, -190a, -193b-3p, -193b-5p, and -545-5p distinguished HFPEF from controls. Four microRNAs (miR-125a-5p, -190a, -550a-5p, and -638) distinguished HFREF from HFPEF. Selective microRNA panels showed stronger discriminative power than N-terminal pro-brain natriuretic peptide (NT-proBNP). In addition, individual or multiple microRNAs used in combination with NT-proBNP increased NT-proBNP's discriminative performance, achieving perfect intergroup distinction. Pathway analysis revealed that the altered microRNAs expression was associated with several mechanisms of potential significance in HF. CONCLUSIONS: We report specific microRNAs as potential biomarkers in distinguishing HF from non-HF controls and in differentiating between HFREF and HFPEF.

How do patients with heart failure with preserved ejection fraction die?

Understanding how patients with heart failure with preserved ejection fraction (HFPEF) die provides insight into the natural history and pathophysiology of this complex syndrome, thereby allowing better prediction of response to therapy in designing clinical trials. This review summarizes the current state of knowledge surrounding mortality rates, modes of death, and prognostic factors in HFPEF. Despite the lack of uniform reporting, the following conclusions may be drawn from previous studies. The mortality burden of HFPEF is substantial, ranging from 10% to 30% annually, and higher in epidemiological studies than in clinical trials. Mortality rates compared with heart failure with reduced ejection fraction (HFREF) appear to be strongly influenced by the type of study, but are clearly elevated compared with age- and co-morbidity-matched controls without heart failure. The majority of deaths in HFPEF are cardiovascular deaths, comprising 51-60% of deaths in epidemiological studies and ∼70% in clinical trials. Among cardiovascular deaths, sudden death and heart failure death are the leading cardiac modes of death in HFPEF clinical trials. Compared with HFREF, the proportions of cardiovascular deaths, sudden death, and heart failure deaths are lower in HFPEF. Conversely, non-cardiovascular deaths constitute a higher proportion of deaths in HFPEF than in HFREF, particularly in epidemiological studies, where this difference may be related to fewer coronary heart deaths in HFPEF. Key mortality risk factors, including age, gender, body mass index, burden of co-morbidities, and coronary artery disease, offer some explanation for the differences in mortality rates observed across studies.