Two-dimensional echocardiographic measurement of left ventricular ejection fraction: Prospective analysis of what constitutes an adequate determination
2DE is increasingly being used to determine LVEF. There remain, however, important questions about the 2DE determination of EF: (1) which 2DE formulae correlate best with contrast ventriculography; (2) how often can a particular formula be applied to a large group of patients; and (3) what effect does 2DE quality or the presence of segmental wall motion abnormalities have on the accuracy of echo determined EF? To answer these questions, we prospectively determined the 2DE EF utilizing 10 differen formulae in 65 consecutive patients undergoing contrast ventriculogram within the following 24 hours. We also sought to examine the ability of trained observers to estimate EF from 2DE. The 2DE EF formulae that utilized biplane areas were generally more accurate than single-plane area or diameter only formulae, but were obtainable in fewer patients. The biplane Simpson's rule yielded a correlation with ventriculogram of r = 0.89, but was available in only 34 patients. While the single-plane formulae were slightly less accurate, they were measured in more patients; ellipsoid single-plane apical four-chamber r = 0.80, N = 56, and short ellipse r = 0.86, N = 47. The measured EF in patients with akinetic segments yielded a greater standard error of the mean, although correlations remained adequate when compared to the normal patient population. The EF from patients with poor quality as compared to good quality echo studies had a slightly greater standard error, but correlations were little affected. Thus biplane formulae for calculating EF yield better correlations, but are available from fewer patients than single-plane formulae. An estimate of EF was sufficiently accurate for most clinical situations and was available in 98% of the patients. The presence of abnormal wall motion or a poor quality 2DE study increased the standard error slightly, but had little effect on correlation with contrast ventriculogram.
Background: Exercise echocardiography (ExE) may assess left ventricular (LV) systolic and diastolic function, LV outflow tract (LVOT) obstruction, and mitral regurgitation (MR). We aimed to evaluate the prognostic value of these assessments during exercise in patients with hypertrophic cardiomyopathy (HCM).
Methods: LV systolic function, LV-derived filling pressures, LVOT gradients, and MR were prospectively evaluated during treadmill ExE in 285 patients with HCM and preserved LV ejection fraction (EF) (≥50%). Recordings were obtained at rest and peak exercise for LV systolic function and at rest and post-exercise for LVOT gradients, MR, and ratio of early LV inflow velocity to early tissue Doppler annulus velocity (E/e´).
Results: Thirty-seven patients (13%) had LVOT obstruction at rest, and 76 (27%) developed exercise-induced LVOT obstruction. New wall motion abnormalities were detected in 38 patients (13%). E/e´>14 was observed in 129 patients at rest (45%) and in 134 at post-exercise (47%). Corresponding figures for significant MR (moderate or severe) were 21 (7%) and 17 (6%). During follow-up (3.9 ± 2.5 years), 27 patients had a hard event, 39 a combined event (hard plus new atrial fibrillation or syncope), and 58 a combined event or intervention. Exercise electrocardiographic testing, exercise LVEF, and the combination of positive ExE and increased E/e´ with exercise predicted outcome. The worst event rate corresponded to patients with raised E/e’ values at post-exercise and positive ExE (annualized hard event-rate of 5.9%).
Conclusions: A comprehensive assessment during ExE is feasible for patients with HCM and preserved LV systolic function, and provides significant incremental prognostic information.
The role of exercise echocardiography (ExE) for the assessment of patients with dyspnea is promising. We aimed to analyze the clinical characteristics and outcome of patients with this condition referred for ExE.
A total of 505 patients (66 ± 11 years, 57% women) referred for evaluation of dyspnea were considered. Mitral regurgitation, ratio of early left ventricular inflow wave to early diastolic annulus wave (E/e′), and wall motion abnormalities (WMAs) were measured at rest and at exercise. Considered events were overall mortality, non-fatal myocardial infarction, late revascularization, and admission for heart failure.
Ischemia was observed in 102 patients (20%), whereas WMAs were already present at rest in 55 patients (11%). A percent achieved of predicted metabolic equivalents >100% was found for most of the patients (70%). During a median follow-up of 3.50 years, 66 patients had events (annualized event rate 3.5%). An E/e′ value of 13 at post-exercise was the best cut-off value to predict events. After adjustment by clinical and ExE variables, the combination of an abnormal ExE and E/e′ values at post-exercise ≥13 was an independent predictor of events (hazard ratio = 3.67, 95% confidence interval = 2.11–6.38, p < 0.001). The worse outcome corresponded to patients with abnormal ExE and raised E/e′ values at post-exercise (annualized event rate 17.2%). Patients with normal E/e′ values at post-exercise had better outcome irrespective of the ExE results (annualized event rate 2.2% with normal ExE and 2.9% with abnormal ExE), whereas patients with high E/e′ values at post-exercise but normal ExE results were at intermediate risk (annualized event rate 5.0%).
Despite favorable ExE results, event rate remains high among patients with dyspnea referred for ExE, which may have a role to predict outcome in this setting. Patients with both raised E/e′ values at post-exercise and abnormal ExE results are at the highest event risk.
We compared the incidence of left ventricular systolic dysfunction (LVSD) among patients with left bundle branch block (LBBB) to a matched cohort of patients with a narrow QRS duration <120 ms (NQRS). We hypothesized patients with preserved ejection fraction (EF) ≥50% and LBBB would have higher incidence of LVSD compared with a matched population of NQRS patients. Patients with LBBB on electrocardiogram within 30 days of a baseline echocardiogram with EF ≥50%, who had at least 1 follow-up echocardiogram ≥6 months later, were matched 1:1 on risk factors for cardiomyopathy to patients with NQRS. Incident LVSD was defined as a decline in EF to ≤45% on follow-up echocardiogram, or heart transplant, receipt of a cardiac device for LVSD (defibrillator or biventricular pacemaker), or implantation of a left ventricular assist device ≥6 months post baseline echocardiogram. Relative risk was calculated using conditional Poisson regression techniques. The final study cohort consisted of 188 patients, 94 with LBBB and 94 with NQRS. On follow-up, progression to LVSD was noted in 36% of LBBB patients and 10% of NQRS patients. The relative risk for LVSD in patients with LBBB was 3.78 (95% confidence interval = 1.98 to 7.19). In conclusion, there is a strong association between LBBB and the subsequent development of LVSD independent of common risk factors for cardiomyopathy.
The complex interaction between pulmonary function, cardiac function and adverse cardiovascular events has only been partially described. We sought to describe the association between pulmonary function with left heart structure and function, all-cause mortality and incident cardiovascular hospitalization.
This study is a retrospective analysis of patients evaluated in a single tertiary care medical center. We used multivariable linear regression analyses to examine the relationship between FVC and FEV1 with left ventricular ejection fraction (LVEF), left ventricular internal dimension in systole and diastole (LVIDS, LVIDD) and left atrial diameter, adjusting for baseline characteristics, right ventricular function and lung hyperinflation. We also used Cox proportional hazards models to examine the relationship between FVC and FEV1 with all-cause mortality and cardiac hospitalization.
A total of 1807 patients were included in this analysis with a median age of 61 years and 50% were female. Decreased FVC and FEV1 were both associated with decreased LVEF. In individuals with FVC less than 2.75 L, decreased FVC was associated with increased all-cause mortality after adjusting for left and right heart echocardiographic variables (hazard ratio [HR] 0.49, 95% CI 0.29, 0.82, respectively). Decreased FVC was associated with increased cardiac hospitalization after adjusting for left heart size (HR 0.80, 95% CI 0.67, 0.96), even in patients with normal LVEF (HR 0.75, 95% CI 0.57, 0.97).
In a tertiary care center reduced pulmonary function was associated with adverse cardiovascular events, a relationship that is not fully explained by left heart remodeling or right heart dysfunction.
2016, Journal of the American Society of Echocardiography
Recommendations for testing in patients with low pretest probability of coronary artery disease differ in guidelines from no testing at all to different tests. The aim of this study was to assess the value of exercise echocardiography (ExE) to define outcome in this population.
A retrospective analysis was conducted of 1,436 patients with low pretest probability of coronary artery disease (<15%) who underwent initial ExE. Overall mortality, major adverse cardiac events (MACEs), defined as cardiac death or nonfatal myocardial infarction, and revascularization during follow-up, were assessed. Ischemia (development of new wall motion abnormalities with exercise) and fixed wall motion abnormalities were measured.
The mean age was 50 ± 12 years. Resting wall motion abnormalities were seen in 13 patients (0.9%) and ischemia in 108 (7.5%). During follow-up, 38 patients died, 10 of cardiac death (annualized death rate, 0.39%); 20 patients had MACEs (annualized MACE rate, 0.21%); and 48 patients (29 with ischemia) underwent revascularization (annualized revascularization rate, 0.51%). The number and percentage of MACEs in the abnormal and normal ExE groups were similar (two [1.7%] vs 18 [1.4%], P = .70), as was the annualized MACE rate (0.31% vs 0.21%, P = .50). Peak left ventricular ejection fraction exhibited a nonsignificant trend for predicting MACEs (P = .11). The number of studies needed to detect an abnormal finding was 12.6 and to detect a patient with extensive ischemia was 26.1.
ExE offers limited prognostic information in patients with low pretest probability of coronary artery disease. The small number of abnormal findings on ExE and low event rates and the large number of studies needed to detect an abnormal finding limit further the value of imaging in this population.
El propósito de este estudio es evaluar el valor pronóstico de la disfunción sistólica ventricular izquierda inducida por el ejercicio en pacientes hipertensos con ecocardiograma en reposo normal y sin enfermedad arterial coronaria.
De nuestra base de datos de pacientes referidos a ecocardiografía de ejercicio, se identificó a 93 pacientes hipertensos, con fracción de eyección del ventrículo izquierdo en reposo normal (≥ 50%), sin cardiopatía estructural ni evidencia de enfermedad arterial coronaria en la angiografía. Del total, 39 pacientes desarrollaron disfunción sistólica ventricular izquierda inducida por el ejercicio (definida como caída de la fracción de eyección del ventrículo izquierdo por debajo de 50% en el máximo ejercicio) y 54 mostraron una respuesta normal de la fracción de eyección del ventrículo izquierdo al ejercicio. El seguimiento medio fue 6,1 ± 3,7 años. Los objetivos primarios fueron muerte por cualquier causa, muerte cardiaca, aparición de insuficiencia cardiaca y el evento combinado de muerte cardiaca o insuficiencia cardiaca.
La aparición de disfunción sistólica ventricular izquierda inducida por el ejercicio se asoció con mayor riesgo de muerte por cualquier causa (hazard ratio = 3,4; intervalo de confianza del 95%, 1,1-10,3), muerte cardiaca (hazard ratio = 5,6; intervalo de confianza del 95%, 1,1-29,4), insuficiencia cardiaca (hazard ratio = 8,9; intervalo de confianza del 95%, 1,8-44,2) y del evento combinado (hazard ratio = 5,7; intervalo de confianza del 95%, 1,7-19,0). En un análisis multivariable, la disfunción sistólica ventricular izquierda inducida por el ejercicio continuó asociándose de manera independiente con mayor riesgo de insuficiencia cardiaca (hazard ratio = 6,9; intervalo de confianza del 95%, 1,3-37,4) y del evento combinado de muerte cardiaca o insuficiencia cardiaca (hazard ratio = 4,5; intervalo de confianza del 95%, 1,2-16,0).
La aparición de disfunción sistólica ventricular izquierda inducida por el ejercicio en pacientes hipertensos con fracción de eyección del ventrículo izquierdo normal en reposo y ausencia de enfermedad arterial coronaria es un potente predictor de eventos cardiacos y podría ser un marcador precoz de cardiopatía hipertensiva.
We sought to assess the prognostic value of exercise-induced left ventricular systolic dysfunction in hypertensive patients with normal resting echocardiography and absence of coronary artery disease.
From our database of patients referred for treadmill exercise echocardiography, we identified 93 hypertensive patients with preserved resting left ventricular ejection fraction (≥ 50%), no evidence of structural heart disease, and absence of coronary artery disease on angiography. Overall, 39 patients developed exercise-induced left ventricular systolic dysfunction (defined as a decrease in left ventricular ejection fraction below 50% at peak exercise) and 54 exhibited a normal left ventricular ejection fraction response to exercise. The mean follow-up was 6.1 (3.7) years. End points were all-cause mortality, cardiac death, heart failure, and the composite event of cardiac death or heart failure.
Patients who developed exercise-induced left ventricular systolic dysfunction were at higher risk of death from any cause (hazard ratio = 3.4; 95% confidence interval, 1.1-10.3), cardiac death (hazard ratio = 5.6; 95%CI, 1.1-29.4), heart failure (hazard ratio = 8.9; 95% confidence interval, 1.8-44.2), and the composite end point (hazard ratio = 5.7; 95% confidence interval, 1.7-19.0). In the multivariate analysis, exercise-induced left ventricular systolic dysfunction remained an independent predictor of both heart failure (hazard ratio = 6.9; 95% CI, 1.3-37.4) and the composite event of cardiac death or heart failure (hazard ratio = 4.5; 95% confidence interval, 1.2-16.0).
In hypertensive patients with preserved resting left ventricular ejection fraction and absence of coronary artery disease, exercise-induced left ventricular systolic dysfunction is a strong predictor of cardiac events and may represent early hypertensive heart disease.
