Low-dose Dobutamine Echocardiography Research Articles

Assessment of myocardial viability using echocardiographic strain imaging in patients with ST-elevation myocardial infarction: comparison with cardiac PET imaging.

A speckle tracking echocardiographic (STE) strain imaging can predict myocardial viability. The study compared the STE strain imaging using low-dose dobutamine stress with 18fluoro-deoxyglucose positron emission tomographic (18FDG-PET) imaging for the detection of myocardium viability. We studied 57 patients with ST-elevation myocardial infarction (STEMI) having angiographic evidence of total arterial cut off and akinetic myocardium. These patients underwent low-dose dobutamine echocardiography and 18FDG-PET imaging. The STE was used to measure the peak systolic longitudinal and circumferential strain and strain rate at rest and after low-dose dobutamine stress. A total of 298 akinetic segments were evaluated. The viable myocardium showed an increased strain and strain rate values following the dobutamine stress in comparison to the nonviable myocardium. The peak longitudinal strain rate [AUC 0.83 (95% confidence interval (CI) 0.67-0.99], p = 0.001; optimal cutoff - 0.64s-1 for sensitivity 0.87 and specificity 0.81), post-dobutamine peak longitudinal strain rate [AUC 0.94 (95% CI 0.87-1.00), p = 0.001; optimal cutoff - 0.85s-1 for sensitivity 0.89 and specificity 0.77), change in peak longitudinal strain rate [AUC 0.93 (95% CI 0.86-1), p = 0.001; optimal cutoff - 0.2s-1 for sensitivity 0.87 and specificity 0.87] predicted viability. The post-dobutamine peak circumferential strain rate [AUC 0.92 (95% CI 0.81-1.0), p = 0.001; optimal cutoff - 1.1s-1 for sensitivity and specificity 0.86], were predictor of viability. Both resting and post-dobutamine longitudinal and circumferential strain rate had better accuracy for the prediction of viability. The resting and post-dobutamine stress STE strain and strain rate parameters can assess the viability in akinetic segments.

Comparison of Contrast Enhanced Low-Dose Dobutamine Stress Echocardiography with 99mTc-Sestamibi Single-Photon Emission Computed Tomography in Assessment of Myocardial Viability.

INTRODUCTION:Dobutamine stress echocardiography (DSE) and myocardial perfusion scan are the commonly used modalities to detect viable myocardium. DSE is comparatively cheaper and widely available but has a lower sensitivity.AIM:We aimed to compare contrast-enhanced low-dose dobutamine echocardiography (LDDE) and gated 99mTc-sestamibi myocardial perfusion scan (MPS) for the degree of agreement in the detection of myocardial viability.METHODS:We studied 850 left ventricular segments from 50 patients (42 men, mean age 55.5 years), with coronary artery disease and left ventricular systolic dysfunction (ejection fraction < 40%), using contrast-enhanced LDDE and 99mTc-Sestamibi gated SPECT. Segments were assessed for the presence of viability by both techniques and head to head comparisons were made.RESULTS:Adequate visualisation increased from 80% in unenhanced segments to 96% in contrast-enhanced segments. Of the total 850 segments studied, 290 segments (34.1%) had abnormal contraction (dysfunctional). Among these, 138 were hypokinetic (16.2% of total), 144 were severely hypokinetic or akinetic (16.9% of total), and 8 segments were dyskinetic or aneurismal (0.9% of total). Among 151 segments considered viable by technetium, 137 (90.7%) showed contractile improvement with dobutamine; in contrast, only 8 of the 139 segments (5.7%) considered nonviable by technetium had a positive dobutamine response. The per cent of agreement between technetium uptake and a positive response to dobutamine was 78.6% with kappa = 0.63, suggestive of a substantial degree of agreement between the two modalities.CONCLUSION:Use of contrast-enhanced LDDE significantly increased the adequate endocardial border visualisation. Furthermore, this study showed a strong degree of agreement between the modalities in the detection of viable segments. So, contrast-enhanced LDDE appears to be a safe and comparable alternative to MPS in myocardial viability assessment.

Erratum to: Intra-procedural determination of viability by myocardial deformation imaging: a randomized prospective study in the cardiac catheter laboratory.

The benefit of revascularization for functional recovery depends on the presence of viable myocardial tissue. Myocardial deformation imaging allows determination of myocardial viability. In a first approach, we assessed the optimal cutoff value to determine preserved viability by layer-specific echocardiographic myocardial deformation imaging at rest and low-dose dobutamine (DSE) echocardiography: regional endocardial circumferential strain (eCS) <−19% at rest was as accurate as eCS at DSE. In a main study, 123 patients (66% men, age 59 ± 6 years) with relevant coronary stenoses and corresponding severe regional myocardial dysfunction were included and randomized in 2 groups after coronary angiography: group A: intra-procedural myocardial deformation imaging in the cardiac catheter laboratory (CLab), determination of myocardial viability by regional eCS <−19%, in case of positive viability immediate coronary intervention in the same session. Group B: two-step determination of myocardial viability by cardiovascular magnetic resonance (CMR), in case of positive viability coronary intervention. After 18 months follow-up an analysis of the endpoints regarding cardiovascular events, left ventricular (LV) function, and comparison of cost was performed. Group A (N = 61) and group B (N = 62) showed no differences concerning localization of the coronary stenosis, comorbidities, or medical therapy. Cardiovascular events at 18-month follow-up were as follows: group A 13% (N = 10) vs. group B 14% (N = 9, p = 0.288); improvement of LV function: group A: +7 ± 2% vs. group B: +7 ± 3%, p = 0.963; costs: group A: 3096 Dollar vs. group B: 6043 Dollar, p < 0.001. Intra-procedural determination of myocardial viability by myocardial deformation imaging in the CLab is feasible, safe, and cost effective and may become an emerging alternative to the current practice of two-stage viability diagnostics.

124 Stroke volume determined flow reserve does not predict the true severity of low-flow low-gradient aortic stenosis and is not a robust marker of contractile reserve in patients undergoing low-dose dobutamine echocardiography

BackgroundDuring low-dose dobutamine stress echocardiography (LDDSE) in low-flow low-gradient aortic stenosis (LFLGAS), both the aortic stenosis (AS) severity and the presence of contractile reserve (CR) are conventionally assessed based on...

Intra-procedural determination of viability by myocardial deformation imaging: a randomized prospective study in the cardiac catheter laboratory.

The benefit of revascularization for functional recovery depends on the presence of viable myocardial tissue. Myocardial deformation imaging allows determination of myocardial viability. In a first approach, we assessed the optimal cutoff value to determine preserved viability by layer-specific echocardiographic myocardial deformation imaging at rest and low-dose dobutamine (DSE) echocardiography: regional endocardial circumferential strain (eCS) <-19% at rest was as accurate as eCS at DSE. In a main study, 123 patients (66% men, age 59 ± 6 years) with relevant coronary stenoses and corresponding severe regional myocardial dysfunction were included and randomized in 2 groups after coronary angiography: group A: intra-procedural myocardial deformation imaging in the cardiac catheter laboratory (CLab), determination of myocardial viability by regional eCS <-19%, in case of positive viability immediate coronary intervention in the same session. Group B: two-step determination of myocardial viability by cardiovascular magnetic resonance (CMR), in case of positive viability coronary intervention. After 18 months follow-up an analysis of the endpoints regarding cardiovascular events, left ventricular (LV) function, and comparison of cost was performed. Group A (N = 61) and group B (N = 62) showed no differences concerning localization of the coronary stenosis, comorbidities, or medical therapy. Cardiovascular events at 18-month follow-up were as follows: group A 13% (N = 10) vs. group B 14% (N = 9, p = 0.288); improvement of LV function: group A: +7 ± 2% vs. group B: +7 ± 3%, p = 0.963; costs: group A: 3096 Dollar vs. group B: 6043 Dollar, p < 0.001. Intra-procedural determination of myocardial viability by myocardial deformation imaging in the CLab is feasible, safe, and cost effective and may become an emerging alternative to the current practice of two-stage viability diagnostics.

Galectin-3 and fibulin-1 in systolic heart failure - relation to glucose metabolism and left ventricular contractile reserve

BackgroundHeart failure (HF) patients with diabetes (DM) have an adverse prognosis and reduced functional capacity, which could be associated with cardiac fibrosis, increased chamber stiffness and reduced left ventricular (LV) contractile reserve. Galectin-3 (Gal-3) and fibulin-1 are circulating biomarkers potentially reflecting cardiac fibrosis. We hypothesize that plasma levels of Gal-3 and fibulin-1 are elevated in HF patients with DM and are associated with reduced LV contractile reserve in these patients.MethodsA total of 155 patients with HF with reduced ejection fraction underwent a low-dose dobutamine echocardiography and blood sampling for biomarker measurements. Patients were classified according to history of DM and an oral glucose tolerance test (OGTT) as: normal glucose tolerance (NGT) (n = 70), impaired glucose tolerance (IGT) (n = 25) and DM (n = 60).ResultsGalectin-3 levels were elevated in DM patients as compared to non-diabetic patients (P = 0.02), while higher fibulin-1 levels were observed in HF patients with IGF and DM (P = 0.07). Reduced LV contractile reserve was associated with increasing Gal-3 levels (β = −0.19, P = 0.03) although, this association was attenuated after adjustment for estimated glomerular filtration rate (P = 0.66). Fibulin-1 was not associated with LV contractile reserve (P = 0.71).ConclusionsGalectin-3 and fibulin-1 levels were elevated in HF patients with impaired glucose metabolism. However, reduced LV contractile reserve among HF patients with DM does not to have an independent impact on plasma Gal-3 and fibulin-1 levels.

Differentiation between Clinical and Academic Myocardial Viability. Complementary Myocardial Perfusion SPECT and Low Dose Dobutamine Echocardiography Role vs. Histopathological Study

Background: Rest-Redistribution thallium(R-RD Tl) imaging has high negative predictive value (NPV) but low positive predictive value (ppv) for the prediction of recovery of regional myocardial dysfunction after revascularization (Rev). Combining myocardial perfusion (MP) and functional data with nitrate-enhanced gated SPECT MIBI (GSM) at rest appears to be a promising approach for viability detection. Aim of the Study: Differentiate between clinical and academic viability. Methods: Total of 66 patients with CAD underwent R-RD Tl,2 sets of resting GSM using 2 MIBI injections, and echocardiography at rest andafter low dose dobutamine (LDD). One hour before GSM2, trimetazidine (TMZ) andnitrate, had been given. All pts had their echo repeated after (Rev) as a golden standard for clinical viability one year later. Myocardial biopsy was taken for mitochondrial assessment as a golden standard for academic viability. Results: 389/1122 segments were found to have abnormal resting wall motion (RWM) on echo. 165/217 hypokinetic, 48/102 akinetic and 6/66 dyskinetic showed contractile response for LDD echo. The MP images showed normal uptake, complete, partial reversibility and poor uptake in Tl, GSM1 and GSM2 images as following:(58,31,47), (36,22,35), (198,119,190) and (32,148,50) of segments respectively. Sensitivity and specificity of Tl, GSM1 and GSM2 and LDD echo for clinical viability had been found respectively to be (94.9%,74.1%), (59.9%,93.6%), (93.5%, 90%) and (78.5%,100%). Mitochondrial degeneration had been found to be more in the segments with partial reversibility and those with poor uptake with sensitivity and specificity of (90,85.6%), (57.2%,94.2%), (89.4%,98%) and (75%, 88.2%) respectively. From this data we can grade viability into 4 grades. Conclusion: Clinical definition of viability is better looked for in GSM2. Viability could be assessed into 4 grades.

Utility and safety of three-dimensional contrast low-dose dobutamine echocardiography in the evaluation of myocardial viability early after an acute myocardial infarction.

IntroductionThe aim of the study was to determine the utility and safety of three-dimensional contrast low-dose dobutamine echocardiography (3DCLDDE) in the evaluation of myocardial viability early after ST-elevation myocardial infarction (STEMI).Material and methodsWe prospectively evaluated a group of 100 consecutive patients. Myocardial viability was assessed using dobutamine echocardiography in 76 patients with segmental wall motion abnormalities, including 37 patients evaluated using 3DCLDDE and 39 patients evaluated using a standard low-dose dobutamine echocardiography protocol (LDDE), alternately.ResultsSingle ventricular ectopic beats were observed during the test in 1 (2.5%, 1, p = 1) patient in the 3DCLDDE group, while pain (1, p = 1) dyspnea (1, p = 1), single ventricular beats (2, p = 1), and complex ventricular arrhythmia (2, p = 0.49) were noted in 4 (10%) patients in the LDDE group. Five-year survival was 89% in the 3DCLDDE group and 87% in the LDDE group.Conclusions3DCLDDE and LDDE are equally safe and useful in patients after STEMI.

The Value of Using Pulsed Tissue Doppler Mitral Annulus Velocity during Dobutamine Stress Echocardiography for Assessment of Myocardial Viability in Patients with Coronary Artery Disease before Revasularization

Background: Assessment of viability could be of significance in ischemic and heart failure patients before deciding for revascularization. The use of Dobutamine stress echocardiography has the disadvantage of subjective visual evaluation of regional wall motion, so, new technologies have been modified; one of these is to assess mitral annular velocity using tissue Doppler imaging. Aim: The aim of this study was to evaluate the value of Pulsed wave tissue Doppler mitral annulus velocity with dobutamine echocardiography in assessment of myocardial viability and prediction of functional recovery of wall motion abnormalities after revasularization in patients with coronary artery disease. Patients and methods: The study group included 40 patients, selected consecutively from patients presented to Ain Shams university Hospitals with coronary artery disease as proved by diagnostic coronary angiography and recommended for potential coronary revascularization. Each patient underwent baseline transthoracic echocardiography, in addition to low dose dobutamine echocardiography using TDI at mitral annulus in 6 different walls. All patients were subjected to revascularization (30 by PCI and 10 by CABG) then followed up after 6 months by transthoracic echocardiography to assess improvement in EF and SWMA. Results: Using the 16 segment method, a total of 640 segments were studied: 250 Segments were considered nondysfunctional (39%), 390 Segments were dysfunctional: of which, severely hypokinetc (216, 55.4 % of abnormal), 158 segments akinetic (40.5% of abnormal), and 16 Segments were dyskinetic (4.1% of abnormal). The mean SWM index at rest was 1.9 (0.39).Using low dose dobutamine echocardiography, 220 segments were detected to be viable (56.4%), while 170 were non-viable (43.6%). In order to relate the results of TDI, The 16 segments were reevaluated into 6 walls per patient. Using this method, 240 walls were studied. 19 walls were excluded due to technical difficulties in assessment of TDI. Pulsed wave TDI demonstrated that dysfunctional areas had lower systolic velocities compared to areas considered as normal. Similarly, the increase from baseline to DSE (ΔTDI) was higher in nondysfunctional areas vs. dysfunctional areas. However, there was no significant difference in the mean TDI at rest for viable and non-viable walls as detected by dobutamine stress echocardiography. But the increase in TDI velocity with peak dobutamine was significantly more in viable (1.97±0.44) vs. nonviable (1.14±0.54) walls, with p<0.0001.The ejection fraction improved from 39.87±8.22 (mean + STD) at baseline to 46.13±8.58 (mean + STD) at follow-up. The score index of the segmental wall motion during follow up after revascularization was 1.45±0.29 (mean+STD). Among the total dysfunctional segments detected at baseline echocardiography, follow-up echo postoperatively showed improvement by ≥1 score in 239 segments (61.3 %).In the 220 dobutamine positive segments, 182 segments improved postrevacsularization (82.7%) while 38 did not show improvement (17.3%), whereas in the segments designated as dobutamine non-viable, 122 segments were not improved (71.8%) and 48 segments (28.2%) improved post revascularization. Taking improvement as the gold standard for viability, sensitivity of dobutamine is: 82.7%, specificity 71.8%, PPV 79.1%, NPV 76.3%. Using TDI method, 115 (79.3%) walls were diagnosed as viable by this method, while 30 walls were nonviable (20.7%). 80 walls (55.2% of total studied walls) were detected to be viable by both dobutamine conventional 2D echocardiography and dobutamine TDI echocardiography (systolic wave), On the other hand, 27 walls (18.6% of total studied walls) were detected to be non-viable by both methods. However, 38 walls (26.2% of total abnormal walls) showed discordance between the two methods. The improvement of 74 walls of 80 combined TDI& DSE positive walls, making a sensitivity of 90.2%, similarly 24 of 27 concordant TDI & DSE negative walls did not improve, making a specificity of 92.3%. Conclusion: The current study confirmed the importance of using TDI in different mitral annular sites, as an objective tool in detecting myocardial viability, and to improve the sensitivity and specificity of DSE.

LOW FLOW, LOW GRADIENT AORTIC STENOSIS IN THE CARDIAC CATHETERIZATION LAB

Low-Flow, Low-Gradient (LF, LG) aortic stenosis (AS) is diagnosed based on a high degree of suspicion and can be confirmed non-invasively by low dose Dobutamine echocardiography (echo). Invasive hemodynamic study of the aortic valve may be necessary in certain circumstances. 82 year old man

Left ventricular remodeling after acute myocardial infarction: the influence of viability and revascularization - an echocardiographic substudy of the VIAMI-trial.

BackgroundViability seems to be important in preventing ventricular remodeling after acute myocardial infarction (AMI). We investigated the influence of viability, as demonstrated with low-dose dobutamine echocardiography, and the role of early revascularization on the process of left ventricular (LV) remodeling after AMI.MethodsWe retrospectively investigated 224 patients who were initially included in the viability-guided angioplasty after acute myocardial infarction-trial (VIAMI-trial). Patients in the VIAMI-trial did not undergo a primary or rescue percutaneous coronary intervention and were stable in the early in-hospital phase. Patients underwent viability testing within 72 hours after AMI. Patients with viability were randomized to an invasive strategy or an ischemia-guided strategy. Follow-up echocardiography was performed at a mean of 205 days. In this echocardiographic substudy, patients were divided into three new groups: group 1, viable and revascularized before follow-up echocardiogram; group 2, viable, but medically treated; and group 3, non-viable patients.ResultsGroup 1 showed preservation of LV volume indices. The ejection fraction (EF) increased significantly from 54.0% to 57.5% (P = 0.047). Group 2 showed a significant increase in LV volume indices with no improvement in EF (53.3% versus 53.0%, P = 0.86). Group 3 showed a significant increase in LV volume indices, with a decrease in EF from 53.5% to 49.1% (P = 0.043). Multivariate logistic regression analysis indicated the number of viable segments and revascularization during follow-up as independent predictors for EF improvement, especially in patients with lower EF at baseline.ConclusionViability early after AMI is associated with improvement in LV function after revascularization. When viable myocardium is not revascularized, the LV tends to remodel with increased LV volumes, without improvement of EF. Absence of viability results in ventricular dilatation and deterioration of EF, irrespective of revascularization status.Trial registrationNCT00149591 (assigned: 6 September 2005).Electronic supplementary materialThe online version of this article (doi:10.1186/1745-6215-15-329) contains supplementary material, which is available to authorized users.

Evaluation of coronary microvascular function by left ventricular contractile reserve with low-dose dobutamine echocardiography

Coronary microvascular function has important diagnostic and prognostic implications but routine assessment is difficult. The index of microcirculatory resistance (IMR) is a reliable but invasive measure. We evaluated whether left ventricular contractile reserve (CR), measured with strain imaging on dobutamine echocardiography (DSE), is a reliable non-invasive measure of coronary microvascular function. Forty-five patients underwent low-dose DSE and invasive coronary angiography with IMR measurement in the left anterior descending artery. Global mean peak systolic longitudinal strain was measured in three apical views at rest, and with low-dose DSE. CR was the difference between the resting and low-dose values. Mean IMR was 19.8 (range 6-104): mean peak global systolic strain at rest was -17.90% and at low-dose was -21.46%, giving a mean CR of +3.6% (20% relative increase). IMR and CR were significantly correlated, IMR(-1)=(0.0014×CR+0.05), r=0.64, p<0.001. CR of ≥10% relative increase identified IMR <25 (100% sensitivity and specificity) and <16 (93% sensitivity, 50% specificity [AUC=0.84]). CR ≥20% identified IMR of <16 (78% sensitivity, 82% specificity) with CR ≥ 41% having 100% specificity. LV CR with low-dose DSE may be used to estimate IMR non-invasively. An impaired CR indicates coronary microvascular dysfunction.

The role of echocardiography in the management of interventional valve repair

The prevalence of valve disease rises with advanced age, and about 1 in 8 individuals aged 75 or older have moderate or severe valvular disease. A proportion of these patients is at high or prohibitive risk for surgical valve replacement and is now considered for interventional valve repair as transcatheter aortic valve implantation (TAVI) or percutaneous mitral valve repair e.g. with the MitraClip device (MitraClip). 2D echocardiography is the method of choice for the diagnosis and quantification of valve disease. In patients with aortic valve stenosis, 2D TTE and 2D TEE allow for a detailed analysis of valve function and morphologic characteristics of the aortic valve apparatus. Furthermore, low-dose dobutamine echocardiography can help to confirm the diagnosis of true severe stenosis in patients with low transaortic gradients. The exact quantification of the aortic annulus diameter is crucial for the planning and success rate of TAVI. Due to the elliptic shape of the aortic annulus, 2D measurements may underestimate dimensions. 3D TEE can overcome these limitations and allows for a correct measurement of the aortic annulus with high correlation to other methods like computer tomography. The MitraClip procedure reproduces the double orifice open heart surgical technique using a clip to join the opposing leaflets at the location of the mitral regurgitation origin. Anatomic suitability of the mitral valve is assessed by TEE and the whole device application is done under echocardiographic guidance. The critical step in this procedure is the correct positioning of the clip device above the origin of the regurgitant jet, with the clip arms perpendicular to the line of coaptation. Only 3D TEE is able to provide real-time imaging to guide the clip device in the left ventricle and to ensure the exact alignment within the mitral leaflets.

Haemodynamic response during low-dose dobutamine infusion in patients with chronic systolic heart failure: comparison of echocardiographic and invasive measurements

To investigate whether left ventricular (LV) systolic shortening velocity (s'), diastolic lengthening velocity (e'), and non-invasively estimated LV filling pressure (E/e') during low-dose dobutamine echocardiography (LDDE) reflect invasive measures of cardiac output and pulmonary capillary wedge pressure (PCWP) in stable patients with chronic systolic heart failure. Fourteen patients with heart failure (aged 65 ± 8 years, LVEF 36 ± 8%) underwent simultaneous tissue Doppler echocardiography and invasive measurements of cardiac output and PCWP by right heart catheterization at rest and during dobutamine infusion at rates of 10 and 20 µg/kg/min. Cardiac output increased from rest to peak dobutamine (4.9 ± 1.2 to 6.6 ± 2.0 L/min, P < 0.001) and correlated with the peak systolic tissue velocity (s') at rest (R = 0.61, P = 0.02) and during dobutamine stimulation (R = 0.79, P < 0.001). Increases in early diastolic mitral inflow (E, 74.9 ± 29.0-90.8 ± 29.5 cm/s) and LV lengthening (e', 6.5 ± 2.4-8.2 ± 2.8 cm/s) velocities were observed during LDDE leaving the E/e' ratio unchanged. Although a mean PCWP was also unchanged from rest to peak dobutamine (16.6 ± 8.3-14.2 ± 9.2, P = 0.25), E/e' and PCWP only correlated at rest (R = 0.64, P = 0.014). The LV systolic shortening velocity is closely associated with cardiac output during LDDE in CHF patients. Dobutamine stimulation increases early diastolic mitral inflow and lengthening velocities, but the E/e' ratio does not reflect the PCWP during LDDE, which warrants some caution in converting changes in E/e' into changes in LV filling pressure. The sample size is, however, small and the observation need to be confirmed in a larger population.

Percutaneous coronary intervention in patients with ischemic cardiomyopathy and viable myocardium: A high dose dobutamine stress echocardiography study

Background The treatment of patients with ischaemic cardiomyopathy is still problematic. The choice of revascularization of these patients – especially who have substantial viability – is not widely implemented due to confusion about its benefit. Objectives This work aimed to evaluate prospectively the response of left ventricular function to low as well as high dose dobutamine in patients with ischaemic cardiomyopathy showing substantial viability, with and without improved resting left ventricular ejection fraction after coronary angioplasty. Methods Fifty patients with ischaemic cardiomyopathy (LVEF ⩽40%) and substantial viability (⩾2 segments) underwent low and high dose dobutamine echocardiography before and 3 months after percutaneous coronary intervention. Patients were divided into group 1, patients with, and group 2, patients without significant improvement in resting LVEF (5% by echocardiography) after revascularisation. The response of LVEF during dobutamine stress echocardiography was compared in these two groups. Results Patients were matched for baseline characteristics except for the history of myocardial infarction which was more in group 2. The CCS functional class for angina and the NYHA functional class for heart failure were both improved after PCI in both groups but with a remarkable improvement in group 1. Myocardial viability increased much more in group 1 than group 2 after PCI (6.3 vs. 4 viable segments before and 6.8 vs. 4.4 viable segments respectively after, p 34% vs. 31%, 46% vs. 41% and 34% vs. 32% respectively, p So, the improvement in LVEF (⩾5%) was only found in group 1 and not in group 2. Conclusion The LV function was improved only in patients with improved resting LVEF and improved myocardial viability after PCI.

Abnormal glucose metabolism is associated with reduced left ventricular contractile reserve and exercise intolerance in patients with chronic heart failure

To investigate the associations between glucose metabolism, left ventricular (LV) contractile reserve, and exercise capacity in patients with chronic systolic heart failure (HF). From an outpatient HF clinic, 161 patients with systolic HF were included (mean age 70 ± 10 years, 69% male, 59% had ischaemic heart disease, mean LV ejection fraction (LVEF) 37 ± 9%). Thirty-four (21%) patients had known diabetes mellitus (DM). Oral glucose tolerance testing (OGTT) classified patients without a prior DM diagnosis as normal glucose tolerance (NGT), impaired glucose tolerance or new DM. All patients completed low-dose dobutamine echocardiography (LDDE) and 154 patients a 6-min walking distance test (6MWD). Compared with patients with NGT, patients with known DM had lower resting LVEF (33.4 vs. 39.1%, P < 0.05) and higher E/e' (13.9 vs. 11.4, P < 0.05). During LDDE, an increase in LVEF could be observed in all glycemic groups (mean 8.2% absolute increase), but the contractile reserve was lower in patients with known DM (-5.4%, P = 0.001) and new DM (-3.5%, P = 0.035) compared to patients with NGT. 6MWD was lower in known DM (349 m) and new DM (379 m) compared with NGT (467 m) (P < 0.001). Differences in clinical variables, resting echocardiographic parameters or contractile reserve, did not explain the exercise intolerance related to diabetes. Diabetes, known or newly detected by OGTT, is independently associated with reduced LV contractile reserve and exercise intolerance in outpatients with systolic HF. These findings may offer one explanation for the excess mortality related to diabetes in HF.

Improved clinical outcome after invasive management of patients with recent myocardial infarction and proven myocardial viability: primary results of a randomized controlled trial (VIAMI-trial)

BackgroundPatients with ST-elevation myocardial infarction (STEMI) not treated with primary or rescue percutaneous coronary intervention (PCI) are at risk for recurrent ischemia, especially when viability in the infarct-area is present. Therefore, an invasive strategy with PCI of the infarct-related coronary artery in patients with viability would reduce the occurrence of a composite end point of death, reinfarction, or unstable angina (UA).MethodsPatients admitted with an (sub)acute myocardial infarction, who were not treated by primary or rescue PCI, and who were stable during the first 48 hours after the acute event, were screened for the study. Eventually, we randomly assigned 216 patients with viability (demonstrated with low-dose dobutamine echocardiography) to an invasive or a conservative strategy. In the invasive strategy stenting of the infarct-related coronary artery was intended with abciximab as adjunct treatment. Seventy-five (75) patients without viability served as registry group. The primary endpoint was the composite of death from any cause, recurrent myocardial infarction (MI) and unstable angina at one year. As secondary endpoint the need for (repeat) revascularization procedures and anginal status were recorded.ResultsThe primary combined endpoint of death, recurrent MI and unstable angina was 7.5% (8/106) in the invasive group and 17.3% (19/110) in the conservative group (Hazard ratio 0.42; 95% confidence interval [CI] 0.18-0.96; p = 0.032). During follow up revascularization-procedures were performed in 6.6% (7/106) in the invasive group and 31.8% (35/110) in the conservative group (Hazard ratio 0.18; 95% CI 0.13-0.43; p < 0.0001). A low rate of recurrent ischemia was found in the non-viable group (5.4%) in comparison to the viable-conservative group (14.5%). (Hazard-ratio 0.35; 95% CI 0.17-1.00; p = 0.051).ConclusionWe demonstrated that after acute MI (treated with thrombolysis or without reperfusion therapy) patients with viability in the infarct-area benefit from a strategy of early in-hospital stenting of the infarct-related coronary artery. This treatment results in a long-term uneventful clinical course. The study confirmed the low risk of recurrent ischemia in patients without viability.Trial registrationClinicalTrials.gov: NCT00149591.

Viability Tested with Dobutamine Stress Echocardiography and Prognosis Early after Acute Myocardial Infarction: A Meta-Analysis

In non-high risk patients treated without primary PCI for acute myocardial infarction (AMI), the updated American Heart Association/American College of Cardiology guidelines recommend a selective pharmacoinvasive strategy (IIb, level C). Early risk assessment is essential to select patients with an increased risk for ischemic events or cardiac death. A potential prognostic value has been ascribed to viability in the infarct region. Viability-testing with Low Dose Dobutamine echocardiography (LDDE) can safely be performed in the early phase after AMI. Since the prognostic value of viability after acute myocardial infarction remains unclear and is still debated, we performed a meta-analysis of post-infarction studies to elucidate the importance and prognostic value of viability early after AMI. The literature was scanned by formal searches of electronic databases from 1966 to June 2010. We used the following selection criteria for inclusion in this meta-analysis: a) viability testing with LDDE within 14 days after Acute Myocardial Infarction (AMI), b) preserved left ventricular function (ejection fraction(EF) ≥40% or wall motion score index (WMSI) ≤1.9), c) prognosis scored by clinical endpoints (death, AMI or unstable angina (UA)). Eight observational studies were included in the meta-analysis (2301 patients). Results: The presence of viability was strongly associated with an increase in ischemic cardiac events [OR 5.0 (1.53 - 16.36), p=0.008]. No predictive value was found for mortality [OR 0.91 (0.38 - 2.18), p=0.84]. In conclusion, patients with preserved left ventricular function and proven viability early after AMI are at risk for ischemic cardiac events, without any difference in mortality (Metaanalysis, acute myocardial infarction, viability, echocardiography).

Usefulness of Low-Dose Dobutamine Echocardiography to Predict Response and Outcome in Patients Undergoing Cardiac Resynchronization Therapy

A substantial proportion of patients who meet the current guidelines for cardiac resynchronization therapy (CRT) fail to respond to this pacing modality. Although appropriate patient selection and left ventricular (LV) lead location have been ascribed as determinants of CRT response, the interaction among contractile reserve, dynamics of dyssynchrony, and lead location is not well understood. The present study prospectively evaluated the effect of contractile reserve and dobutamine-induced changes in LV synchrony, in relation to the LV lead location, as predictors of the response to CRT. In the present study, 31 patients were prospectively evaluated and underwent low-dose dobutamine echocardiography. The dobutamine-induced increase in ejection fraction (contractile reserve [CR]) was measured, and the most mechanically delayed segment was identified to classify patients into 2 groups. Group 1 had a CR of >20% and a LV lead position concordant with the mechanically delayed segment. Group 2 included the remaining patients (i.e., low CR, discordant LV lead position, or both). Patients in group 1 were significantly more likely to have an echocardiographic response at 6 months (80% of group 1 vs 29% of group 2, p = 0.018) and had an improved 2-year heart failure hospitalization-free survival rate (90% in group 1 vs 33% in group 2, p = 0.006). In conclusion, low-dose dobutamine echocardiography provides information that can help to predict responders to CRT. The response rates and heart failure hospitalization-free survival were improved in those patients with a CR >20% and an LV lead tip concordant with the most delayed mechanical segment.

Réunion commune : Société française neurovasculaire (SFNV) – Société française d’hypertension artérielle (SFHTA)

This study assesses the prognostic value of myocardial viability recognized as a contractile response to inotropic stimulation in patients with left ventricular (LV) dysfunction in a large-scale prospective, multicenter, observational study. Four hundred twenty-five patients (mean age 61 ± 10 years) with angiographically proven coronary artery disease, previous (>3 months) myocardial infarction, and severe LV dysfunction (ejection fraction <35%; mean 28 ± 6%) were enrolled in the study. Each patient underwent low-dose dobutamine echocardiography (up to 10 μg/kg/min). Myocardial viability was identified as a rest–stress variation (Δ) in the wall motion score index (WMSI), in which each segment was scored from 1 = normal to 4 = dyskinetic in a 16-segment model of the left ventricle. Myocardial viability was identified as an improvement of ≥0.40 in WMSI. All patients were followed for a median of 3.1 years. One hundred eighty-eight were revascularized either by coronary artery bypass grafting (n = 118) or coronary angioplasty (n = 70). The only end point analyzed was cardiac death. In the revascularized group, cardiac death occurred in 4 of the 52 patients with and in 37 of the 136 patients without myocardial viability (7.7% vs 27.2%, p <0.003). Kaplan-Meier survival estimates showed a better outcome for those patients with compared to patients without myocardial viability who underwent coronary revascularization (90.1% vs 62%, p <0.0078). Thus, in severe LV ischemic dysfunction, myocardial viability by low-dose dobutamine echocardiography is associated with improved survival in revascularized patients.