A comparison of the effects of indexation on standard echocardiographic measurements of the left heart in a healthy multi-racial population.

Accurate reference ranges for measurements from echocardiography rely on an understanding of the distribution of each measurement in the diverse, multi-racial world population. The aim of this study was to determine the influence of gender, age and ethnicity on common echocardiographic measures of the left heart, and to evaluate the effect of different methods of indexation on measurements from healthy, non-Caucasian populations. Standard echocardiographic measurements of left heart size and left ventricular mass (LVM) were assessed in 341 healthy volunteers. Indexation was performed using height, body surface area, and fat free mass (FFM). Quantile regression was used to derive age-adjusted values at the 5th, 50th and 95th‰ of each measurement, by gender, within Caucasians. The effect of indexation method across ethnic groups could then be compared. Indexation of m-mode dimensions may overcompensate for body size, resulting in people of smaller build (women and those of South or East Asian descent) developing higher indexed values than those of larger build (men and people of Maori or Pacific descent). Indexation of 2D volumes by any method improves the integration of values across ethnic groups, with FFM yielding the greatest integration. LVM increases with age, suggesting that the static reference values currently recommended for this measurement may not be appropriate. There are important differences in the distribution of measurements of left heart size by gender, ethnicity and age.

Prognostic role of echocardiography and brain natriuretic peptide in symptomatic breathless patients in the community.

AIMS: Brain natriuretic peptide (BNP), left ventricular (LV) systolic function, and mitral filling pattern (MFP) are prognostic indicators in patients with heart failure (HF). This study evaluated the potential role of E/Ea for predicting cardiovascular (CV) events in patients with suspected HF. This non-invasive measure of LV filling pressure has been shown to predict outcome in more advanced HF, but not in mild HF in the community. METHODS AND RESULTS: Two hundred and twenty-eight elderly symptomatic general practice patients (dyspnoea/oedema) were recruited and underwent clinical evaluation, NT-proBNP assay, and comprehensive echocardiography. The Kaplan-Meier analysis of time to first CV hospitalization or CV death was performed for 1 year after presentation according to nominated thresholds of LV systolic function, NT-proBNP, MFP, and E/Ea ratio. Mean age was 70.3 +/- 7.3 years, mean NT-proBNP was 111.4 +/- 185.8, and 148 (65%) were female. Twenty-six patients (11%) experienced a CV event within 18 months of baseline (6 deaths and 20 admissions). Time to first CV event predicted by NT-proBNP (P < 0.0001), MFP (P = 0.009), and E:Ea (P = 0.0076), but not EF (P = 0.098). When NT-proBNP was elevated, E:Ea >15 identified a group of patients with lower survival (P < 0.0001). CONCLUSION: Both E/Ea and NT-proBNP predicted hospitalization and when used in a two-step approach (NT-proBNP first, followed by E/Ea), the combination of both (elevated NT-proBNP and elevated E/Ea) identified those patients at highest risk, thus supporting a complementary approach for echocardiography and NT-proBNP in patients with HF symptoms.

Comparison of different methods for detection of diastolic filling abnormalities.

OBJECTIVE: Heart failure is associated with poor prognosis and the differentiation of patients on the basis of diastolic filling patterns helps to identify several groups of patients with incrementally higher risk. However, this is reliant on accurate definition of filling patterns. The aim of this study was to compare preload reduction with contrast-enhanced pulmonary venous Doppler recordings for the correct assessment of diastolic filling pattern. METHODS: In all, 20 patients with heart failure and 25 healthy volunteers were studied on 2 separate days. Preload reduction was achieved with the Valsalva maneuver (nonstandardized and standardized) and sublingual nitroglycerin. Responses were compared among the 3 methods and the filling patterns obtained on each day with the various methods compared. RESULTS: Although pulmonary venous Doppler improved the diastolic classification over mitral Doppler, preload reduction resulted in better classification and improved sensitivity, specificity, and positive and negative predictive values. No advantage was observed for either the standardized Valsalva or pharmacologic preload reduction. CONCLUSION: Preload reduction is an essential part of the assessment of diastolic filling grade in patients with heart failure as it can identify pseudonormal filling (mildly increased filling pressures), reversible restrictive filling (high filling pressures), and nonreversible restrictive filling pattern (very high filling pressures).

Quantitative evaluation of regional endocardial visualisation with second harmonic imaging and contrast left ventricular opacification in heart failure patients.

AIMS: Wall motion score index (WMSI) is an important prognostic indicator in heart failure (HF) patients but requires endocardial visualisation. This study evaluated the role tissue harmonic imaging (THI) and contrast opacification (LVO) for improving endocardial visualisation and the determination of WMSI in HF patients. METHODS AND RESULTS: Thirty-one HF patients and 30 controls underwent apical echocardiography with fundamental imaging (FUND), THI and THI with contrast agent (Levovist). Visualisation and motion were graded in the six segments from each of the apical two and four chamber views. Both THI and LVO reduced the percentage of non-visualised segments (FUND 13.6%, THI 5.6%, LVO 2.8%, p=0.01) in the controls, but in HF patients, only THI improved visualisation (% segments not visualised FUND 9.7%, THI 3.5%, LVO 4.8%, p=0.06). The anterior and lateral walls were the least well visualised with FUND, but improved with LVO (anterior p=0.0026, lateral p=0.0003). No improvement was seen in the inferior wall (p=0.30) or septum (p=0.2). WMSI was similar by all methods and negatively correlated with ejection fraction (FUND r=-0.69, THI r=-0.74, LVO r=-0.77, all p<0.001). CONCLUSION: THI improved endocardial visualisation in all subjects and LVO offered additional benefit in the controls, but not in HF patients. Regional endocardial visualisation was inconsistent. Thus, both patient factors and wall segment site need to be considered when using contrast agents for endocardial visualisation.

Association of fat-free mass and training status with left ventricular size and mass in endurance-trained athletes.

OBJECTIVES: We sought to study the relationship between left ventricular (LV) size and body composition in male endurance athletes and age-matched control subjects. BACKGROUND: Endurance training is associated with increases in both left ventricular mass (LVM) and left ventricular end-diastolic dimension (LVEDD) in athletes. In other populations, LVM is independently predicted by fat-free mass (FFM). We hypothesized that the increase in LV size and mass observed with training may be a normal response to increased FFM. METHODS: Twelve young and 18 older male endurance athletes and 10 young and 18 older untrained men underwent exercise testing, echocardiography, and dual-photon x-ray absorptiometry body composition analysis. Univariate correlates (Spearman) and multivariate determinants of LVM and LVEDD were sought from: height, height(1.4), height(2.7), height(3.0), body surface area (BSA), FFM, weight, and body mass index. Un-indexed and indexed LVM and LVEDD were then compared. RESULTS: Athletes were of a similar age, weight, and height, but had higher FFM and maximum oxygen uptake than untrained men. Both LVM and LVEDD were correlated with body size, including FFM, BSA, weight, and height (all p < 0.05). On multivariate analysis, FFM was the only independent predictor of both LVM (R(2) = 0.36, p < 0.001) and LVEDD (R(2) = 0.35, p < 0.001). Furthermore, LVM and LVEDD (un-indexed and indexed to BSA and height) were different between athletes and non-athletes, but not when indexed to height(2.7) or FFM. CONCLUSIONS: Both LVM and LVEDD are predicted by FFM in endurance athletes, and when indexed to FFM, no training-related differences were observed. Thus, the extent of LV remodeling (athletic heart) in trained individuals may reflect a normal physiologic response to increased FFM induced by training.

Effect of tissue harmonic imaging and contrast upon between observer and test-retest reproducibility of left ventricular ejection fraction measurement in patients with heart failure.

AIMS: To investigate the effects of tissue harmonic imaging (THI) and contrast chamber opacification (LVO) upon measurement variability and reproducibility of echocardiographic left ventricular (LV) volume and ejection fraction (EF) measurements in patients with heart failure (HF). BACKGROUND: Echocardiography is often used in HF patients to determine LV volumes and EF. However, current echo methods are variable and may not be applicable for repeat testing in individual patients. THI and LVO have both been shown to improve endocardial visualisation, but it remains to be determined whether this results in better measurement reproducibility. METHODS: Thirty-one HF patients and 30 control subjects underwent echocardiography on two separate days. LV volumes were measured under four different imaging conditions: fundamental, THI, LVO and LVO with ECG-triggered Power Doppler. Chamber opacification, pulmonary transit time (PTT), endocardial enhancement, reproducibility and bias were assessed. RESULTS: Chamber opacification was inferior and the PTT longer in the HF patients. PTT was related to LV volumes, EF, jugular venous pressure and mitral filling pattern. THI improved endocardial visualisation, and although LVO improved endocardial visualisation in the controls, it offered no benefit over THI in the HF patients. LV volumes and EF were different for each method and THI was the least variable method for repeat measurements. CONCLUSIONS: THI improved endocardial visualisation and was the least variable of the techniques. LVO offered no further advantage in patients with HF and thus cannot be routinely advocated and since LV volumes and EF were different for each, these methods are neither comparable nor interchangeable for follow-up assessments.

Plasma amino-terminal pro-brain natriuretic peptide and accuracy of heart-failure diagnosis in primary care: a randomized, controlled trial.

OBJECTIVES: The purpose of this study was to determine the effect of amino-terminal pro-brain natriuretic peptide (N-BNP) on the diagnostic accuracy of heart failure (HF) in primary care. BACKGROUND: The accurate diagnosis of patients with suspected HF presenting in primary care is difficult. Amino-terminal pro-brain natriuretic peptide is present in high levels in cardiac dysfunction and may improve the diagnostic accuracy of HF in primary care. METHODS: The Natriuretic Peptides in the Community Study was a prospective, randomized controlled trial of the effect of N-BNP on the accuracy of HF diagnosis. Patients presenting to their general practitioner (GP) with symptoms of dyspnea and/or peripheral edema were included. The GPs formulated an initial diagnosis based on clinical assessment. All patients underwent a full cardiologic assessment that included echocardiography and N-BNP. Each patient was randomized to the BNP group (GP received the N-BNP result) or the control group (GP did not receive the N-BNP result). Patients were then reviewed by their GP, and their diagnosis was reviewed. The primary end point was the accuracy of the GPs' diagnoses compared with the panel standard. RESULTS: A total of 305 patients were included; mean age was 72 years, 65% were female. Seventy-seven patients met the panel criteria for HF. The diagnostic accuracy improved 21% in the BNP group and 8% in the control group (p = 0.002). The main impact of N-BNP measurement on diagnostic accuracy was the GPs' correctly ruling out HF. The number needed to diagnose by N-BNP measurement was seven patients. CONCLUSION: This study demonstrates that N-BNP measurement significantly improves the diagnostic accuracy of HF by GPs over and above customary clinical review.

Left ventricular diastolic filling and systolic function of young and older trained and untrained men.

Aging is associated with impaired early diastolic filling; however, the effect of endurance training on resting diastolic function in older subjects is unclear. Heart rate and ventricular loading conditions affect mitral inflow velocities measured by Doppler echocardiography; therefore, tissue Doppler imaging of mitral annular velocity, which is relatively preload independent, was combined with mitral inflow velocity and maximal oxygen consumption (V(o2 max)) in young (20-35 yr) and older (60-80 yr) trained and untrained men to determine whether endurance training is associated with an attenuation of age-associated changes in diastolic filling. As expected, V(o2 max) was higher in trained men (P < 0.01) and lower in older men (P < 0.01). Peak early mitral inflow velocity (E) and early-to-late mitral inflow velocity ratios were lower in older vs. young men (P < 0.01); however, there was no training effect (P > 0.05). Peak early mitral annular velocity (E') was higher and peak late mitral annular velocity (A') was lower in young vs. older men (P < 0.01). A significant interaction effect was found for A', E'/A', and peak systolic mitral annular velocity (S'). Training was associated with lower A' in young and higher A' in older men. S' was greater in trained vs. untrained older men (P < 0.05), but it was similar in trained and untrained young men. These findings suggest that early diastolic filling is not affected by training in older men, and the effect of training on A' and S' is different in young and older men.

The effect of an integrated care approach for heart failure on general practice.

BACKGROUND: Recent studies have investigated specific strategies for heart failure management. None has involved collaboration between primary and secondary care. Potential gains for patients may result from collaborative strategies. OBJECTIVE: To assess the effect of an integrated management approach for patients with heart failure on general practice. METHODS: The study design was a cluster randomized controlled trial of integrated primary/ secondary care compared with usual care for heart failure patients. The study took place at Auckland Hospital, New Zealand and involved 197 patients admitted with an episode of heart failure. Patients were randomized to management group or control group (who received "usual" care). Management group patients received early clinical review, education sessions, a personal diary for medications and weight, and regular clinical follow-up alternating between GP and hospital clinic. Follow-up was for 12 months. RESULTS: Patients visited GPs frequently (median 14 visits, range 0-40), with no statistical difference between the two groups. Heart failure was the most common reason for consulting the GP. There was no relationship between GP consultations and patients' attendance at the study clinic, or hospital admissions. Management group GPs and patients expressed a high level of satisfaction. CONCLUSION: GP consultation rates were not affected by the programme. Further research will determine if general practice based programmes result in further gains.

Pseudonormal mitral filling pattern predicts hospital re-admission in patients with congestive heart failure.

OBJECTIVES: We sought to investigate whether pseudonormal (PN) filling was associated with death or hospital admission in patients with congestive heart failure (CHF). BACKGROUND: The high mortality rate associated with CHF is related to many clinical and echocardiographic variables. In particular, a short mitral deceleration time and restrictive diastolic filling predict death and/or hospital admission. We hypothesized that differentiating patients with nonrestrictive filling might identify an intermediate PN group that may be associated with intermediate risk. METHODS: A total of 115 patients admitted to the hospital for exacerbation of CHF symptoms underwent pre-discharge Doppler echocardiography to determine mitral inflow (before and after preload reduction) and pulmonary venous return. Patients were followed up for one year, and all-cause mortality and re-admission data were analyzed. RESULTS: The classification of filling patterns was: abnormal relaxation (AR) in 46 (40%) patients, pseudonormal (PN) filling in 42 (36.5%) patients and restrictive filling pattern (RFP) in 27 (23.4%) patients. When comparing the RFP group with the AR group, all-cause mortality was higher (38.4% vs. 17.4%, p = 0.033), hospital admission was higher (70.3% vs. 54.3%, p = 0.073), death/hospital admission was higher (77.8% vs. 56.5%, p = 0.02), CHF hospital admission was higher (40.7% vs. 15.2%, p = 0.01) and death/CHF hospital admission was higher (62.9% vs. 26.1%, p = 0.0005). Mortality in the PN group was not significantly different from that in the two other groups, but re-admissions were higher than the AR group (76.2% vs. 54.3%, p = 0.006), as was death/re-admission (78.6% vs. 56.5%, p = 0.004) and death/CHF re-admission (47.6% vs. 26.1%, p = 0.03). Re-admissions in the PN and RFP groups were comparable. CONCLUSIONS: In a general hospital population of older patients with CHF, PN filling was associated with hospital admission rates similar to those seen with restrictive filling. The combined end point of death/CHF hospital admission was similar for restrictive filling and AR. Measurement of these variables is easy to add to routine clinical echocardiography and may provide important prognostic information in a wide range of patients with CHF.