Effect of Low-Sodium versus Conventional Sodium Dialysate on Left Ventricular Mass in Home and Self-Care Satellite Facility Hemodialysis Patients: A Randomized Clinical Trial.

BACKGROUND: Fluid overload in patients undergoing hemodialysis contributes to cardiovascular morbidity and mortality. There is a global trend to lower dialysate sodium with the goal of reducing fluid overload. METHODS: To investigate whether lower dialysate sodium during hemodialysis reduces left ventricular mass, we conducted a randomized trial in which patients received either low-sodium dialysate (135 mM) or conventional dialysate (140 mM) for 12 months. We included participants who were aged >18 years old, had a predialysis serum sodium ≥135 mM, and were receiving hemodialysis at home or a self-care satellite facility. Exclusion criteria included hemodialysis frequency >3.5 times per week and use of sodium profiling or hemodiafiltration. The main outcome was left ventricular mass index by cardiac magnetic resonance imaging. RESULTS: The 99 participants had a median age of 51 years old; 67 were men, 31 had diabetes mellitus, and 59 had left ventricular hypertrophy. Over 12 months of follow-up, relative to control, a dialysate sodium concentration of 135 mmol/L did not change the left ventricular mass index, despite significant reductions at 6 and 12 months in interdialytic weight gain, in extracellular fluid volume, and in plasma B-type natriuretic peptide concentration (ratio of intervention to control). The intervention increased intradialytic hypotension (odds ratio [OR], 7.5; 95% confidence interval [95% CI], 1.1 to 49.8 at 6 months and OR, 3.6; 95% CI, 0.5 to 28.8 at 12 months). Five participants in the intervention arm could not complete the trial because of hypotension. We found no effect on health-related quality of life measures, perceived thirst or xerostomia, or dietary sodium intake. CONCLUSIONS: Dialysate sodium of 135 mmol/L did not reduce left ventricular mass relative to control, despite improving fluid status. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: The Australian New Zealand Clinical Trials Registry, ACTRN12611000975998.

Clinical Characteristics and Outcomes of Patients with Amphetamine-Associated Cardiomyopathy in South Auckland, New Zealand.

BACKGROUND: Amphetamine-associated cardiomyopathy (AAC) is becoming an increasingly recognised entity. The characteristics and outcomes of these patients are poorly understood. METHODS: Thirty patients admitted with heart failure and echocardiographic evidence of cardiomyopathy between 2005 and 2014 and who had a documented history of amphetamine abuse that was considered an important factor in the causation of their cardiomyopathy were retrospectively identified. RESULTS: Mean age at presentation was 40±10 years with a male predominance (n=25, 83%). The majority were of indigenous Maori ethnicity. At presentation, four patients were in cardiogenic shock. Five patients required intensive care unit (ICU) admission for inotropic support and mechanical ventilation. Fifteen had severe left ventricular (LV) dilation (mean LV end-diastolic dimension 6.8±1.0cm) and all patients had severe LV dysfunction (mean LV ejection fraction 22±8%). Despite optimal heart failure therapy, LV size remained significantly dilated with minimal improvement in LV function. During median follow-up of 18 months, five patients died from end-stage heart failure and 17 had at least one readmission with decompensated heart failure. CONCLUSION: Amphetamine-associated cardiomyopathy was seen predominantly in young indigenous Maori men. They presented with severe cardiomyopathy, often requiring ICU admission. Severe LV dilation and significant LV dysfunction persisted despite treatment and mortality was high.

Update: Rationale and design of the Sodium Lowering In Dialysate (SoLID) trial: a randomised controlled trial of low versus standard dialysate sodium concentration during hemodialysis for regression of left ventricular mass.

After the publication of our paper Dunlop et al. "Rationale and design of the Sodium Lowering In Dialysate (SoLID) trial: a randomised controlled trial of low versus standard dialysate sodium concentration during hemodialysis for regression of left ventricular mass", we became aware of further data correlating left ventricular (LV) mass index at baseline and their corresponding mass at 12 months, using cardiac magnetic resonance imaging (MRI) in patients on hemodialysis. The original published sample size for the SoLID trial of 118 was a conservative estimate, calculated using analysis of covariance and a within person Pearson's correlation for LV mass index of 0.75. New data communicated to the SoLID trial group has resulted in re-calcuation of the sample size, based upon a within person Pearson's correlation of 0.8 but otherwise unchanged assumptions. As a result, the SoLID trial will now recruit 96 participants.

Rationale and design of the Myocardial Microinjury and Cardiac Remodeling Extension Study in the Sodium Lowering in Dialysate trial (Mac-SoLID study).

BACKGROUND: The Sodium Lowering in Dialysate (SoLID) trial is an ongoing a multi-center, prospective, randomised, single-blind (assessor), controlled, parallel assignment clinical trial, enrolling 96 home and self-care hemodialysis (HD) patients from 7 centers in New Zealand. The trial will evaluate the hypothesis that lower dialysate [Na+] during HD results in lower left ventricular (LV) mass. Since it's inception, observational evidence has suggested increased mortality risk with lower dialysate [Na+], possibly due to exacerbation of intra-dialytic hypotension and subsequent myocardial micro-injury. The Myocardial Micro-injury and Cardiac Remodeling Extension Study in the Sodium Lowering In Dialysate Trial (Mac-SoLID study) aims to determine whether lower dialysate [Na+] results in (i) increased levels of high-sensitivity Troponin T (hsTnT), a well-established marker of intra-dialytic myocardial micro-injury in HD populations, and (ii) increased fixed LV segmental wall motion abnormalities, a marker of recurrent myocardial stunning and micro-injury, and (iii) detrimental changes in LV geometry due to maladaptive homeostatic mechanisms. METHODS/DESIGN: The SoLID trial and the Mac-SoLID study are funded by the Health Research Council of New Zealand. Key exclusion criteria: patients who dialyse > 3.5 times per week, pre-dialysis serum sodium <135 mM, and maintenance haemodiafiltration. In addition, some medical conditions, treatments or participation in other dialysis trials that contraindicate the study intervention or confound its effects, will be exclusion criteria. The intervention and control groups will receive dialysate sodium 135 mM and 140 mM respectively, for 12 months. The primary outcome measure for the Mac-SOLID study is repeated measures of [hsTnT] at 0, 3, 6, 9, and 12 months. The secondary outcomes will be assessed using cardiac magnetic resonance imaging (MRI), and comprise LV segmental wall motion abnormality scores, LV mass to volume ratio and patterns of LV remodeling at 0 and 12 months. DISCUSSION: The Mac-SoLID study enhances and complements the SoLID trial. It tests whether potential gains in cardiovascular health (reduced LV mass) which low dialysate [Na+] is expected to deliver, are counteracted by deterioration in cardiovascular health through alternative mechanisms, namely repeated LV stunning and micro-injury. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry number: ACTRN12611000975998.

Two causes of ventricular tachycardia in a 26 year-old male.

We present the case of a 26 year-old man who presented to hospital with monomorphic ventricular tachycardia (VT) at a rate of 170bpm after exercising on a treadmill. Multimodality imaging with transthoracic echocardiogram (TTE), cardiac magnetic resonance imaging (CMRI) and computed tomography coronary angiogram (CTCA) demonstrated two causes for ventricular tachycardia; hypertrophic cardiomyopathy (HCM) and an anomalous right coronary artery (RCA) arising from the left coronary sinus, with a potentially malignant interarterial course. Both conditions can be associated with sudden cardiac death (SCD). We discuss the management dilemmas in this unique patient.

Rationale and design of the Sodium Lowering In Dialysate (SoLID) trial: a randomised controlled trial of low versus standard dialysate sodium concentration during hemodialysis for regression of left ventricular mass.

BACKGROUND: The current literature recognises that left ventricular hypertrophy makes a key contribution to the high rate of premature cardiovascular mortality in dialysis patients. Determining how we might intervene to ameliorate left ventricular hypertrophy in dialysis populations has become a research priority. Reducing sodium exposure through lower dialysate sodium may be a promising intervention in this regard. However there is clinical equipoise around this intervention because the benefit has not yet been demonstrated in a robust prospective clinical trial, and several observational studies have suggested sodium lowering interventions may be deleterious in some dialysis patients. METHODS/DESIGN: The Sodium Lowering in Dialysate (SoLID) study is funded by the Health Research Council of New Zealand. It is a multi-centre, prospective, randomised, single-blind (outcomes assessor), controlled parallel assignment 3-year clinical trial. The SoLID study is designed to study what impact low dialysate sodium has upon cardiovascular risk in dialysis patients. The study intends to enrol 118 home hemodialysis patients from 6 sites in New Zealand over 24 months and follow up each participant over 12 months. Key exclusion criteria are: patients who dialyse more frequently than 3.5 times per week, pre-dialysis serum sodium of <135 mM, and maintenance hemodiafiltration. In addition, some medical conditions, treatments or participation in other dialysis trials, which contraindicate the SoLID study intervention or confound its effects, will be exclusion criteria. The intervention and control groups will be dialysed using dialysate sodium 135 mM and 140 mM respectively, for 12 months. The primary outcome measure is left ventricular mass index, as measured by cardiac magnetic resonance imaging, after 12 months of intervention. Eleven or more secondary outcomes will be studied in an attempt to better understand the physiologic and clinical mechanisms by which lower dialysate sodium alters the primary end point. DISCUSSION: The SoLID study is designed to clarify the effect of low dialysate sodium upon the cardiovascular outcomes of dialysis patients. The study results will provide much needed information about the efficacy of a cost effective, economically sustainable solution to a condition which is curtailing the lives of so many dialysis patients. TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry number: ACTRN12611000975998.

Cardiac Computed Tomography to exclude left atrial appendage thrombus in atrial arrhythmias prior to electrical cardioversion during the COVID-19 pandemic.

Nil.

Cardiac MR assessment of aortic regurgitation: holodiastolic flow reversal in the descending aorta helps stratify severity.

PURPOSE: To assess the utility of holodiastolic flow reversal (HDR) in the descending aorta on velocity-encoded cardiac magnetic resonance (MR) images in the stratification of aortic regurgitation (AR) severity. MATERIALS AND METHODS: This study was approved by the institutional review board, with waiver of informed consent. A total of 80 patients (overall mean age, 49 years ± 18 [standard deviation]; 22 women and 58 men) with clinical indication for cardiac MR imaging of the aorta were analyzed retrospectively. Velocity-encoded MR imaging was used to quantify AR and assess for HDR at the level of the middescending aorta. These indexes were compared with a qualitative integrated echocardiographic evaluation of AR severity. Sensitivity and specificity for HDR in the prediction of substantial AR were determined, and logistic regression analysis (with associated odds ratios and C statistics) was performed, with HDR and regurgitant fraction as independent predictors. An additional 42 patients (overall mean age, 48 years ± 21; 12 female and 30 male) were then prospectively evaluated in similar fashion to evaluate a decision model derived from analysis of the first group. RESULTS: HDR predicted severe AR (echo grade, 4) with high sensitivity (100%) and specificity (93%). HDR was highly specific (100%) but had lower sensitivity (61%) for moderate to severe AR (echo grade, 3-4). Integration of HDR and direct AR quantification into a combined stratification model based on analysis of the primary group showed good predictive results in the validation group, with a C statistic of 0.94 for moderate to severe AR and 0.93 for severe AR. CONCLUSION: HDR in the middescending thoracic aorta observed at cardiac MR is indicative of severe AR and can be used in conjunction with quantified regurgitant values obtained from velocity-encoded MR imaging to stratify AR severity.

An NP-led pilot telehealth programme to facilitate guideline-directed medical therapy for heart failure with reduced ejection fraction during the COVID-19 pandemic.

AIMS: Heart failure with reduced ejection fraction (HFrEF) is associated with poor outcomes. While several medications are beneficial, achieving optimal guideline-directed medical therapy (GDMT) is challenging. COVID-19 created a need to explore new ways to deliver care. METHODS: Fifty consecutive patients were taught to identify fluid congestion and monitor their vital signs using BP monitors and electronic scales with NP-led telephone support. Quantitative data were collected and a patient experience interview was performed. RESULTS: The majority (76%) of the cohort (male, 76%; Maori/Pacific, 58%) had a new diagnosis of HFrEF, with 90% having severe left ventricular (LV) dysfunction. There were 216 contacts (129 (60%) by telephone), which eliminated travelling, (time saved, 2.12 hours per patient), petrol costs ($58.17 per patient), traffic pollution (607 Kg of CO2) and time off work. Most (75%) received contact within two weeks and 75% were optimally titrated within two months. Improvements in systolic BP (SBP) (124mmHg to 116mmHg), pulse (78 bpm to 70 bpm) and N-terminal pro-brain natriuretic peptide (NT-proBNP) (292 to 65) were identified. Of the 43 patients who had a follow-up transthoracic echocardiogram (TTE), 33 (77%) showed important improvement in left ventricular ejection fraction (LVEF). CONCLUSIONS: Patients found the process acceptable and experienced rapid titration with less need for clinic review with titration rates comparable with most real-world reports.

Pilot study to assess the influence of beta-blockade on mitral regurgitant volume and left ventricular work in degenerative mitral valve disease.

BACKGROUND: A medical treatment that decreases the likelihood of left ventricular (LV) dysfunction or symptoms would benefit patients with moderate to severe degenerative mitral regurgitation. The aim of this pilot study was to determine the short-term effects of a beta-blocker on mitral regurgitant volume and LV work in these patients. METHODS AND RESULTS: Twenty-five patients with moderate or severe degenerative mitral regurgitation were randomized in a double-blind crossover study to the beta(1)-selective adrenergic blocker metoprolol (mean daily dose, 119 mg; range 23.75 to 190 mg) and placebo for 14+/-3 days. At the end of each treatment period, ascending aortic flow and LV stroke volume were measured by cardiac magnetic resonance imaging, and mitral regurgitant volume was calculated. On beta-blocker, heart rate decreased from 65+/-10 by 10+/-7 bpm (mean+/-SD) and systolic blood pressure decreased from 138+/-18 by 16+/-12 mm Hg (P<0.0001 for both). No significant change occurred in LV ejection fraction (from 65+/-5%; change, -0.6+/-2.7%; P=0.3) or mitral regurgitant volume (from 59+/-36 mL; change, 3+/-13 mL; P=0.3), but forward stroke volume increased from 89+/-21 by 5+/-11 mL (P=0.03). Because heart rate was lower on metoprolol, cardiac output decreased from 5.68+/-1.04 by 0.56+/-0.78 L/min (P=0.001), but a greater decrease occurred in LV output, from 9.51+/-2.22 by 1.30+/-1.08 L/min (P<0.0001). Mitral regurgitant volume per minute decreased from 3.83+/-2.41 by 0.74+/-1.00 L/min (P=0.001). The decrease in LV work on beta-blocker (mean, 21%; 95% confidence interval, 15 to 27) was greater (P=0.001) than the decrease in cardiac output (mean, 9%; 95% confidence interval, 3 to 15). CONCLUSIONS: In this pilot study, short-term treatment with a beta-blocker did not change mitral regurgitant volume per beat but decreased LV work in patients with moderate to severe degenerative mitral regurgitation. Further research is needed to determine whether longer-term treatment with beta-blockers will decrease progressive LV dysfunction and symptomatic deterioration.

Aortic valve stenotic area calculation from phase contrast cardiovascular magnetic resonance: the importance of short echo time.

BACKGROUND: Cardiovascular magnetic resonance (CMR) can potentially quantify aortic valve area (AVA) in aortic stenosis (AS) using a single-slice phase contrast (PC) acquisition at valve level: AVA = aortic flow/aortic velocity-time integral (VTI). However, CMR has been shown to underestimate aortic flow in turbulent high velocity jets, due to intra-voxel dephasing. This study investigated the effect of decreasing intra-voxel dephasing by reducing the echo time (TE) on AVA estimates in patients with AS. METHOD: 15 patients with moderate or severe AS, were studied with three different TEs (2.8 ms/2.0 ms/1.5 ms), in the main pulmonary artery (MPA), left ventricular outflow tract (LVOT) and 0 cm/1 cm/2.5 cm above the aortic valve (AoV). PC estimates of stroke volume (SV) were compared with CMR left ventricular SV measurements and PC peak velocity, VTI and AVA were compared with Doppler echocardiography. CMR estimates of AVA obtained by direct planimetry from cine acquisitions were also compared with the echoAVA. RESULTS: With a TE of 2.8 ms, the mean PC SV was similar to the ventricular SV at the MPA, LVOT and AoV0 cm (by Bland-Altman analysis bias +/- 1.96 SD, 1.3 +/- 20.2 mL/-6.8 +/- 21.9 mL/6.5 +/- 50.7 mL respectively), but was significantly lower at AoV1 and AoV2.5 (-29.3 +/- 31.2 mL/-21.1 +/- 35.7 mL). PC peak velocity and VTI underestimated Doppler echo estimates by approximately 10% with only moderate agreement. Shortening the TE from 2.8 to 1.5 msec improved the agreement between ventricular SV and PC SV at AoV0 cm (6.5 +/- 50.7 mL vs 1.5 +/- 37.9 mL respectively) but did not satisfactorily improve the PC SV estimate at AoV1 cm and AoV2.5 cm. Agreement of CMR AVA with echoAVA was improved at TE 1.5 ms (0.00 +/- 0.39 cm2) versus TE 2.8 (0.11 +/- 0.81 cm2). The CMR method which agreed best with echoAVA was direct planimetry (-0.03 cm2 +/- 0.24 cm2). CONCLUSION: Agreement of CMR AVA at the aortic valve level with echo AVA improves with a reduced TE of 1.5 ms. However, flow measurements in the aorta (AoV 1 and 2.5) are underestimated and 95% limits of agreement remain large. Further improvements or novel, more robust techniques are needed in the CMR PC technique in the assessment of AS severity in patients with moderate to severe aortic stenosis.

Modern evaluation of left ventricular diastolic function using Doppler echocardiography.

The evaluation of left ventricular (LV) diastolic function is an essential component of the echocardiographic examination for dyspneic patients with impaired or preserved LV systolic function. Doppler echocardiography in combination with two-dimensional echocardiographic findings can assist the diagnosis of underlying cardiac dysfunction, give an estimate of LV filling pressures, guide heart failure treatment, and provide important prognostic information. This article reviews the essentials of modern Doppler assessment of diastolic function and highlights recent updates, areas of controversy, and future applications.

Poor outcomes in methamphetamine-associated cardiomyopathy-a growing health issue in New Zealand.

BACKGROUND: Methamphetamine-associated cardiomyopathy (MAC) is increasingly recognised as a serious consequence of chronic metamphetamine use. Evidence to guide management and prognostication of patients with MAC compared to other cardiomyopathies remain limited. METHODS: Clinical characteristics, in-hospital and post-discharge outcomes were collected in consecutive MAC patients at Middlemore Hospital from 2006-2018, and compared with a 1:1 age-range matched cohort with non-ischaemic cardiomyopathy (NCM). RESULTS: Sixty-two patients (eight females, median age 41 years) with MAC were included. MAC patients were younger than the NCM cohort, and the majority were of indigenous Maori ethnicity. MAC patients had higher peak N-terminal pro B-type natriuretic peptide (NT-proBNP) and lower left ventricular (LV) ejection fraction at presentation. No patients died during index admission. However, there were more MAC patients (10 versus two, P=0.030) with cardiogenic shock at presentation. There were 15 deaths in the MAC patients and seven deaths in the NCM patients during follow-up. MAC patients were at increased mortality risk (HR 2.7, 95% confidence interval 1.1-6.2, P=0.029), and had a trend to more heart failure re-admissions. (HR 1.6, 95% CI 1.0-2.8, P=0.075) compared to NCM patients. Baseline LV end diastolic diameter and failure of improvement in right ventricular systolic function during follow-up were independent predictors of mortality, while failure of improvement in LV ejection fraction predicted heart failure readmission in MAC patients. CONCLUSIONS: MAC patients were more likely to be younger, male, of Maori ethnicity and have a worse prognosis when compared to patients with other non-ischaemic cardiomyopathies.

Early direct current cardioversion or ablation for atrial fibrillation or atrial flutter and acute decompensated heart failure.

AIMS: Guidelines recommend initial rate control in haemodynamically stable patients with atrial fibrillation (AF) or atrial flutter (AFL) and acute decompensated heart failure (ADHF). There is limited data on early inpatient rhythm control. We investigated the outcomes of patients managed with early TOE-guided DC cardioversion (DCCV) or ablation. METHODS: We retrospectively analysed patients admitted to a single centre with AF or AFL and ADHF with LVEF≤40% that underwent inpatient TOE-guided DCCV or ablation. The primary endpoint was the one year composite outcome of mortality or rehospitalisation for heart failure. RESULTS: We identified 79 patients, including 33 with AF (32 DCCV, one ablation) and 46 with AFL (22 DCCV, 24 ablation). The primary endpoint occurred in 20%. One-year mortality was 2.5%. There were significantly fewer rehospitalisations for arrhythmia or heart failure with AFL-ablation compared to AFL-DCCV (21% vs 64%, p=<0.01). Clinical recurrence of AF or AFL was 43%. At follow-up LV assessment, LVEF>40% was found in 75% (p=<0.01), including 87% of patients without known cardiomyopathy and 82% of patients in sinus rhythm. CONCLUSION: Early inpatient DCCV or ablation for AF or AFL and ADHF had low mortality rates and rehospitalisation for heart failure with substantial improvement in LV function at follow-up.

Mapping of mitral regurgitant defects by cardiovascular magnetic resonance in moderate or severe mitral regurgitation secondary to mitral valve prolapse.

PURPOSE: In mitral valve prolapse, determining whether the valve is suitable for surgical repair depends on the location and mechanism of regurgitation. We assessed whether cardiovascular magnetic resonance (CMR) could accurately identify prolapsing or flail mitral valve leaflets and regurgitant jet direction in patients with known moderate or severe mitral regurgitation. METHODS: CMR of the mitral valve was compared with trans-thoracic echocardiography (TTE) in 27 patients with chronic moderate to severe mitral regurgitation due to mitral valve prolapse. Contiguous long-axis high temporal resolution CMR cines perpendicular to the valve commissures were obtained across the mitral valve from the medial to lateral annulus. This technique allowed systematic valve inspection and mapping of leaflet prolapse using a 6 segment model. CMR mapping was compared with trans-oesophageal echocardiography (TOE) or surgical inspection in 10 patients. RESULTS: CMR and TTE agreed on the presence/absence of leaflet abnormality in 53 of 54 (98%) leaflets. Prolapse or flail was seen in 36 of 54 mitral valve leaflets examined on TTE. CMR and TTE agreed on the discrimination of prolapse from flail in 33 of 36 (92%) leaflets and on the predominant regurgitant jet direction in 26 of the 27 (96%) patients. In the 10 patients with TOE or surgical operative findings available, CMR correctly classified presence/absence of segmental abnormality in 49 of 60 (82%) leaflet segments. CONCLUSION: Systematic mitral valve assessment using a simple protocol is feasible and could easily be incorporated into CMR studies in patients with mitral regurgitation due to mitral valve prolapse.

Managing catheter ablation for atrial fibrillation: the role of echocardiography.

Atrial fibrillation (AF) is a common arrhythmia associated with the serious clinical consequences of systemic thrombo-embolism and heart failure. Catheter ablation for AF is an evolving treatment option for patients with drug-refractory paroxysmal and persistent AF. The ablation procedure relies on precise knowledge of the left atrium, left atrial appendage, and pulmonary venous anatomy and function. Echocardiography is an integral component of multiple imaging modalities which contribute to its success. Both transoesophageal echocardiography and transthoracic echocardiography provide essential anatomical and functional information to guide all aspects of management. This article reviews the role of echocardigraphy in AF ablation, from appropriate patient selection and pre-procedural screening, to evaluating complications and determining the need for long-term anticoagulation.

Estimation of myocardial strain from non-rigid registration and highly accelerated cine CMR.

Sparsely sampled cardiac cine accelerated acquisitions show promise for faster evaluation of left-ventricular function. Myocardial strain estimation using image feature tracking methods is also becoming widespread. However, it is not known whether highly accelerated acquisitions also provide reliable feature tracking strain estimates. Twenty patients and twenty healthy volunteers were imaged with conventional 14-beat/slice cine acquisition (STD), 4× accelerated 4-beat/slice acquisition with iterative reconstruction (R4), and a 9.2× accelerated 2-beat/slice real-time acquisition with sparse sampling and iterative reconstruction (R9.2). Radial and circumferential strains were calculated using non-rigid registration in the mid-ventricle short-axis slice and inter-observer errors were evaluated. Consistency was assessed using intra-class correlation coefficients (ICC) and bias with Bland-Altman analysis. Peak circumferential strain magnitude was highly consistent between STD and R4 and R9.2 (ICC = 0.876 and 0.884, respectively). Average bias was -1.7 ± 2.0 %, p < 0.001, for R4 and -2.7 ± 1.9 %, p < 0.001 for R9.2. Peak radial strain was also highly consistent (ICC = 0.829 and 0.785, respectively), with average bias -11.2 ± 18.4 %, p < 0.001, for R4 and -15.0 ± 21.2 %, p < 0.001 for R9.2. STD circumferential strain could be predicted by linear regression from R9.2 with an R2 of 0.82 and a root mean squared error of 1.8 %. Similarly, radial strain could be predicted with an R2 of 0.67 and a root mean squared error of 21.3 %. Inter-observer errors were not significantly different between methods, except for peak circumferential strain R9.2 (1.1 ± 1.9 %) versus STD (0.3 ± 1.0 %), p = 0.011. Although small systematic differences were observed in strain, these were highly consistent with standard acquisitions, suggesting that accelerated myocardial strain is feasible and reliable in patients who require short acquisition durations.

Plasma brain natriuretic peptide concentrations in patients with valvular heart disease.

OBJECTIVE: Plasma brain natriuretic peptide (BNP) concentrations predict prognosis in patients with valvular heart disease (VHD), but it is unclear whether this directly relates to disease severity. We assessed the relationship between BNP and echocardiographic measures of disease severity in patients with VHD. METHODS: Plasma BNP concentrations were measured in patients with normal left ventricular (LV) systolic function and isolated VHD (mitral regurgitation (MR), n=33; aortic regurgitation (AR), n=39; aortic stenosis (AS), n=34; mitral stenosis (MS), n=30), and age-matched and sex-matched controls (n=39) immediately prior to exercise stress echocardiography. RESULTS: Compared with controls, patients with VHD had elevated plasma BNP concentrations (MR median 35 (IQR 23-52), AR 34 (22-45), AS 31 (22-60), MS 58 (34-90); controls 24 (16-33) pg/mL; p<0.01 for all). LV end diastolic volume index varied by valve lesion; (MR (mean 77±14), AR (91±28), AS (50±17), MS (43±11), controls (52±13) mL/m(2); p<0.0001). There were no associations between LV volume and BNP. Left atrial (LA) area index varied (MR (18±4 cm(2)/m(2)), AR (12±2), AS (11±3), MS (19±6), controls (11±2); p<0.0001), but correlated with plasma BNP concentrations: MR (r=0.42, p=0.02), MS (r=0.86, p<0.0001), AR (r=0.53, p=0.001), AS (r=0.52, p=0.002). Higher plasma BNP concentrations were associated with increased pulmonary artery pressure and reduced exercise capacity. Despite adverse cardiac remodelling, 81 (60%) patients had a BNP concentration within the normal range. CONCLUSIONS: Despite LV remodelling, plasma BNP concentrations are often normal in patients with VHD. Conversely, mild elevations of BNP occur with LA dilatation in the presence of normal LV. Plasma BNP concentrations should be interpreted with caution when assessing patients with VHD.