Comparison of radionuclide ventriculography and 2D echocardiography for the measurement of left ventricular ejection fraction following acute myocardial infarction

Comparison of contrast agent-enhanced versus non-contrast agent-enhanced real-time three-dimensional echocardiography for analysis of left ventricular systolic function

Ultrasound contrast has shown to improve endocardial border definition. The purpose of this study was to evaluate the value of contrast agent-enhanced versus non-contrast agent-enhanced real-time 3-dimensional echocardiography (RT3DE) for the assessment of left ventricular (LV) volumes and ejection fraction. Thirty-nine unselected patients underwent RT3DE with and without SonoVue contrast agent enhancement and magnetic resonance imaging (MRI) on the same day. An image quality index was calculated by grading all 16 individual LV segments on a scale of 0 to 4: 0, not visible; 1, poor; 2, moderate; 3, good; and 4, excellent. The 3-dimensional data sets were analyzed offline using dedicated TomTec analysis software. By manual tracing, LV end-systolic volume, LV end-diastolic volume, and LV ejection fraction were calculated. After contrast agent enhancement, mean image quality index improved from 2.4 +/- 1.0 to 3.0 +/- 0.9 (p <0.001). Contrast agent-enhanced RT3DE measurements showed better correlation with MRI (LV end-diastolic volume, r = 0.97 vs 0.86; LV end-systolic volume, r = 0.96 vs 0.94; LV ejection fraction, r = 0.94 vs 0.81). The limits of agreement (Bland-Altman analysis) showed a similar bias for RT3DE images with and without contrast agent but with smaller limits of agreement for contrast agent-enhanced RT3DE. Also, inter- and intraobserver variabilities decreased. In a subgroup, patients with poor to moderate image quality showed an improvement in agreement after administration of contrast agent (+/-24.4% to +/-12.7%) to the same level as patients with moderate to good image quality without contrast agent (+/-10.4%). In conclusion, contrast agent-enhanced RT3DE is more accurate in assessment of LV function as evidenced by better correlation and narrower limits of agreement compared with MRI, as well as lower intra- and interobserver variabilities.

Prognostic value of myocardial viability detected by myocardial contrast echocardiography early after acute myocardial infarction

OBJECTIVES

This study sought to determine whether residual myocardial viability determined by myocardial contrast echocardiography (MCE) after acute myocardial infarction (AMI) can predict hard cardiac events.

BACKGROUND

Myocardial viability detected by MCE has been shown to predict recovery of left ventricular (LV) function in patients with AMI. However, to date no study has shown its value in predicting major adverse outcomes in AMI patients after thrombolysis.

METHODS

Accordingly, 99 stable patients underwent low-power MCE at 7 +/- 2 days after AMI. Contrast defect index (CDI) was obtained by adding contrast scores (1 = homogenous; 2 = reduced; 3 = minimal/absent opacification) in all 16 LV segments divided by 16. At discharge, 65 (68%) patients had either undergone or were scheduled for revascularization independent of the MCE result. The patients were subsequently followed up for cardiac death and nonfatal AMI.

RESULTS

Of the 99 patients, 95 were available for follow-up. Of these, 86 (87%) underwent thrombolysis. During the follow-up time of 46 +/- 16 months, there were 15 (16%) events (8 cardiac deaths and 7 nonfatal AMIs). Among the clinical, biochemical, electrocardiographic, echocardiographic, and coronary arteriographic markers of prognosis, the extent of residual myocardial viability was an independent predictor of cardiac death (p = 0.01) and cardiac death or AMI (p = 0.002). A CDI of < or = 1.86 and < or = 1.67 predicted survival and survival or absence of recurrent AMI in 99% and 95% of the patients, respectively.

CONCLUSIONS

The extent of residual myocardial viability predicted by MCE is a powerful independent predictor of hard cardiac events in patients after AMI.

Comparison of the clinical utility of atrial and B type natriuretic peptide measurement for the diagnosis of systolic dysfunction in a low-risk population

BACKGROUND

Measurement of B type natriuretic peptide and its N terminal prohormone (NTproBNP) can now be performed routinely by automated high-throughput immunoassays. The study compared measurement of NTproBNP with measurement of N terminal pro-atrial natriuretic peptide (NTproANP) for detection of ventricular systolic dysfunction in primary care.

METHODS

734 subjects aged >45 years (349 men and 385 women, median age 58 years, range 45-89, interquartile range 51-67 years) from seven representative general practices attended for echocardiography with determination of ejection fraction and completed a questionnaire. Blood samples were collected into gel serum separation tubes (Becton-Dickinson, Franklin Lakes, New Jersey, USA), the serum separated and aliquots stored frozen at -70 degrees C until analyses. Samples were analysed for NTproBNP (Roche Diagnostics, Lewes, UK; coefficient of variation (CV) 3.2-2.4%) and for NTproANP (Biomedica, Vienna, Austria; CV 5.6-10.1%). Echocardiography was used as the diagnostic "gold standard", with ventricular systolic dysfunction defined as abnormal when there was an ejection fraction of <or=40%. Patients were dichotomised by ejection fraction from 50% to 30%, and receiver operating characteristic curves constructed and the area under the curve (AUC) compared.

RESULTS

At 40% ejection fraction, NTproANP and NTproBNP showed AUCs of, respectively, 0.738 (0.601-0.875) and 0.973 (0.958-0.989), p<0.004.

CONCLUSION

NTproBNP is superior to NTproANP for detection of systolic dysfunction.

The expanding role of left ventricular functional assessment using gated myocardial perfusion SPECT: the supporting actor is stealing the scene

BACKGROUND

Gating of single-photon emission computed tomography (SPECT) has significantly improved the reliability and diagnostic accuracy of myocardial perfusion imaging. The functional parameters derived from this technique, mainly left ventricular volumes and ejection fraction, have been demonstrated to be accurate and reproducible. They are able to increase the detection of severe and extensive coronary artery disease and show a significant incremental prognostic power over perfusion abnormalities. Therefore, the importance given to gated SPECT functional data has progressively grown.

DISCUSSION

This circumstance has further expanded the indications for myocardial perfusion imaging and strengthened its position among the different imaging modalities. Moreover, several studies show that the evaluation of ventricular function may have a leading part in justifying the execution of perfusion scintigraphy in various clinical conditions.

AIM

Aim of this review is to describe this evolution of gated SPECT functional assessment from a supporting rank with respect to perfusion, to a main actor position in the field of cardiac imaging.

Changes in echocardiographic variables of left ventricular size and function in a model of canine normovolemic anemia

The objective of this study was to document changes in echocardiographic variables of left ventricular size and function noninvasively during acute normovolemic anemia. This model was developed as a pilot study with the purpose of providing baseline information to investigate the pathophysiology, and more specifically the effect on the heart, of canine babesiosis-induced anemia. The study group comprised of 11 mature healthy Beagle dogs that weighed between 9 and 15 kg. Severe normovolemic anemia was induced over a 3-4-day period by serial bleeding while maintaining normovolemia by autotransfusing plasma and infusing crystalloids. The dogs were then allowed to recover. Preanemic (mean Hct 46.7%, standard deviation [SD] 2.4%) echocardiographic variables of left ventricular performance (Fractional shortening, ejection fraction, end-systolic and end-diastolic ventricular volumes, cardiac index, and heart rate) were compared with those in the severely (mean Hct 15.3%, SD 1.1%), moderately (Hct mean 24.7%, SD 1.5%), and mildly (mean Hct 33.5%, SD 2.5%) anemic states, and between the anemic states. With the exception of end diastolic volume, there was a statistically significant (P < 0.05) increase in all variables in the severely anemic state vs. the preanemic and the mild and moderate anemic states. In concordance with previous invasive models, a hyperdynamic state of the left ventricle develops in response to experimentally induced acute canine normovolemic anemia in the conscious dog. Echocardiography has promise as a noninvasive technique of evaluating the cardiac changes in dogs having canine babesiosis.

Improved assessment of left ventricular volumes and ejection fraction by contrast enhanced harmonic color Doppler echocardiography

AIMS

Test the accuracy of contrast enhanced harmonic color Doppler technique (CHCD) to determine left ventricular volumes and ejection fraction (LVEF) compared to equilibrium radionuclide ventriculography (MUGA).

METHODS AND RESULTS

A total of 35 patients were enrolled (male 74.3%) with the mean age of 64.5 +/- 10 years and 6.8 +/- 4.9 days between echo and MUGA scans. The correlation of LVEF by CHCD with MUGA was better (R2 = 0.89) than that of harmonic 2D (H2D) and of contrast enhanced harmonic 2D (CH2D) (R2 = 0.74, R2 = 0.82, respectively). The RMS residual of CHCD (0.056) was smaller than that of H2D and CH2D (0.079, 0.067, respectively). The LVED and LVES volumes by H2D, CH2D and CHCD correlate well with MUGA but there was a significant over estimation of LVED and LVES volumes by H2D and CH2D as compared to MUGA. Also, the RMS residuals were the lowest for the CHCD method. The CHCD had the highest mean inter-observer agreement (90.9%) for LVEF compared with H2D and CH2D (78.9% and 88.1%, respectively).

CONCLUSIONS

CHCD has been feasible in all patients in the present study and it has shown a good concordance with ejection fraction and volumes provided by MUGA.

Is echocardiography a valid tool to screen for left ventricular systolic dysfunction in chronic survivors of acute myocardial infarction? A comparison with radionuclide ventriculography

OBJECTIVE

To assess the accuracy of echocardiography with Simpson's apical biplane method in screening for left ventricular systolic dysfunction (LVSD) in patients six months after acute myocardial infarction (AMI) as compared with radionuclide ventriculography by assessing the proportion of clinically significant errors that occur with echocardiography.

DESIGN

Comparison of results of echocardiography and radionuclide ventriculography in assessing left ventricular ejection fraction among patients six months after AMI.

SETTING

District general hospital.

PATIENTS

86 patients thrombolysed for AMI at six month follow up.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Correlation coefficients, mean differences, 95% limits of agreement, and differences of clinical significance between left ventricular ejection fraction on echocardiography and on radionuclide ventriculography.

RESULTS

The correlation coefficient between techniques was 0.90, mean difference 1% (p = 0.04), and 95% limits of agreement -13.0% to 10.3%. Only one patient (1.2%, 0.0% to 6.3%) was classified as having normal systolic function on one imaging modality but significant LVSD on the other. Overall accuracy between the two techniques was 86%, kappa value of agreement 0.78.

CONCLUSION

Echocardiography is a valid tool to screen for LVSD in patients six months after AMI, accurately differentiating normal from abnormal systolic function and showing excellent agreement with radionuclide ventriculography. This study supports the use of echocardiography in screening for LVSD in chronic stable patients after AMI or alternative high risk patients, with few differences of major clinical significance likely to occur.

Usefulness of left atrial volume as a predictor of mortality in patients with ischemic cardiomyopathy

Left atrial (LA) volume is a load-independent marker of left ventricular diastolic function. To determine the value of LA volume to predict mortality in patients with ischemic cardiomyopathy, clinical and echocardiographic variables, including Doppler parameters, were evaluated in 109 patients with ischemic cardiomyopathy. LA volume was the only independent predictor of mortality (hazard ratio 1.03, 95% confidence interval 1.001 to 1.057, p = 0.03).

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.

Reliability of reporting left ventricular systolic function by echocardiography: a systematic review of 3 methods

BACKGROUND

An accurate assessment of left ventricular (LV) systolic function is of central importance to the diagnosis and management of heart failure. Echocardiography is currently the technique most widely used for this purpose.

METHODS

A systematic review was performed of the evidence for the accuracy of 3 echocardiographic methods--Simpson's rule, wall motion index (WMI), and subjective visual assessment--compared with radionuclide or contrast ventriculography for the assessment of LV ejection fraction (LVEF).

RESULTS

Twenty-five studies were identified in which data on agreement between echocardiography and reference methods were obtainable. A further 18 studies provided correlation data alone. For Simpson's rule, Bland-Altman limits of agreement (95% CI) ranged from LVEF +/-7% to +/-25% (median +/-18%); for WMI +/-13% to +/-20% (median +/-16%); and for subjective visual assessment +/-16% to +/-24% (median +/-19%). Subject echogenicity, the nature of underlying disease, and the use of additional imaging technology, including secondary harmonic imaging and contrast agents, is likely to influence the accuracy of different methods. No method appears to systematically under- or overestimate LVEF to any major extent.

CONCLUSION

These findings have important implications for the investigation of heart failure and for the practice and reporting of echocardiography.

Prognostication and risk stratification by assessment of left atrioventricular plane displacement in patients with myocardial infarction

BACKGROUND

Mean left atrioventricular plane displacement is strongly related to prognosis in patients with heart failure. We aimed to examine its value for prognostication and risk stratification in patients hospitalised for acute myocardial infarction.

METHODS AND RESULTS

Left atrioventricular plane displacement was assessed by echocardiography in 271 consecutive patients with acute myocardial infarction. Mean prospective follow-up was 628 days. Atrioventricular plane displacement was readily assessed in all patients and was significantly lower in patients who died (n=41, 15.1%) compared to the survivors: 8.2(5.6) v. 10.0(5.5) mm, P<0.0001. Overall mortality was 31.3% in the lowest quartile with regard to atrioventricular plane displacement (<8.00 mm) and 10.1% in the combined upper three quartiles. Thus, the hazard ratio for an atrioventricular plane displacement <8.0 mm compared to 8 mm or more was 3.1, P=0.0001. The combined mortality/heart failure hospitalisation incidence was 43.8% in the lowest and 14.6% in the combined upper three quartiles: Risk ratio 3.0, P<0.0001. In multivariate analysis, including age and history of atrial fibrillation, left atrioventricular plane displacement was an independent prognostic marker.

CONCLUSION

In post-myocardial infarction patients, echocardiographic assessment of atrioventricular plane displacement showed a strong, independent prognostic value. Determination of left atrioventricular plane displacement can be readily performed in virtually all patients, and may in clinical practice facilitate identification of high-risk patients.

A prospective comparison of echocardiographic wall motion score index and radionuclide ejection fraction in predicting outcome following acute myocardial infarction

OBJECTIVE

To characterise echocardiographic wall motion score index (WMSI) as a surrogate measure of left ventricular ejection fraction (EF) following acute myocardial infarction (AMI) and to compare its prognostic value with that of EF measured by radionuclide ventriculography (RNV).

DESIGN

A prospective study to compare baseline echocardiographic WMSI with RNV EF in consecutive patients thrombolysed for AMI, both performed on the same day before discharge, and their relative prognostic values in predicting cardiac events.

SETTING

District general hospital coronary care unit and cardiology department.

PATIENTS

120 consecutive patients free of exclusion criteria thrombolysed for AMI and followed up for a mean (SD) of 13 (10) months.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Correlation coefficients and receiver operating characteristic curve analyses plus cardiac event rates at follow up between RNV EF and echocardiographic WMSI.

RESULTS

WMSI correlated well with RNV EF. The best corresponding WMSIs for EFs 45%, 40%, and 35% were 0.6, 0.8, and 1.1, respectively. There were 42 cardiac events during follow up. Although both RNV EF and WMSI were strong univariate predictors of cardiac events, only WMSI independently predicted outcome in a multivariate model. All three WMSI cut offs significantly predicted events, while an RNV EF cut off of </= 45% v > 45% failed to reach significance.

CONCLUSIONS

Although both RNV and echocardiographic WMSI strongly predicted cardiac outcome, WMSI, a cheaper and more readily available technique, is more discriminatory, especially in cases of mild left ventricular dysfunction following AMI.

Comparison of four echocardiographic techniques for measuring left ventricular ejection fraction

Accurate quantitative measurement of left ventricular (LV) ejection fraction (EF) by 2-dimensional echocardiography is limited by subjective visual endocardial border detection. Both harmonic and precision contrast microbubbles provide better delineation of endocardial borders than fundamental imaging. The aim of this study was to correlate 2-dimensional echocardiographic quantification of LVEF measured by 4 currently available techniques with radionuclide angiography. A total of 50 patients who underwent radionuclide (EF) measurement (47 of 50 had technically difficult echocardiograms by fundamental imaging) underwent echocardiography by 4 methods: fundamental alone, fundamental with contrast, harmonic alone, and harmonic with contrast. Three echocardiologists measured the biplane 2-dimensional echocardiographic LVEF independently and were blinded to radionuclide angiography. The correlation of echocardiographic EF with radionuclide EF improved incrementally with each method. However, contrast with harmonic imaging provided the closest correlation (r = 0.95, 0.96, and 0.95 as assessed by the 3 independent analysts.

Enhanced left ventricular endocardial border delineation with an intravenous injection of SonoVue, a new echocardiographic contrast agent: A European multicenter study

The safety and efficacy of SonoVue (also referred to as BR1), a new contrast agent for delineating endocardial border of the left ventricle after intravenous administration, was assessed. Two hundred and eighteen patients with suspected coronary artery disease undergoing fundamental echocardiography for the assessment of left ventricle were enrolled in a prospective multicenter, single blind, cross-over study with random sequence allocation of four different doses of SonoVue. Endocardial border definition in the apical and parasternal views was scored as 0 = not visible, 1 = barely visible, and 2 = well visualized before and after contrast enhancement. Analysis was performed by two pairs of off-site observers. Safety of SonoVue was also assessed. Results of our study indicated that the mean improvements in the endocardial border visualization score were as follows: 3.1 +/- 7.8 (95% CI, 2.5 and 3.7) for 0.5 ml, 3.4 +/- 8.0 (95% CI, 2.8 and 4.0) for 1 ml, 3.4 +/- 7.9 (95% CI, 2.8 and 4.0) for 2 ml, and 3.7 +/- 8.0 (95% CI, 3.1 and 4.3) for 4 ml (P < 0.05 for all doses from baseline). Changes from baseline in endocardial visualization scores were also seen in the apical views (P < 0.05) and they were dose-dependent (P < 0.001). Similar enhancements of endocardial visualization scores were observed in the apical views in patients with suboptimal baseline echocardiographic images. Diagnostic confidence for assigning a score and image quality also were significantly better following contrast enhancement. No significant changes in the laboratory parameters and vital signs were noted following contrast enhancement, and the side effects were minimal. It was concluded that SonoVue is safe and effective in delineating endocardial border, including in patients with suboptimal baseline images.

Accurate measures of left ventricular ejection fraction using electron beam tomography: a comparison with radionuclide angiography, and cine angiography

BACKGROUND

Quantitative determination of ejection fraction is predicated on precise measurement of end-diastolic and end-systolic volumes of the left ventricle. Contrast enhanced electron beam tomography (EBT), with excellent temporal and spatial resolution, has the potential for highly accurate measures of ejection fraction.

METHODS

EBT protocol used a short axis scan of the left ventricle (8-12 levels, apex to base) during infusion of iodinated contrast. To assess the accuracy of the measured left ventricular ejection fraction (LVEF), we compared EBT with first-pass radionuclide angiography (RNA) and cine angiography (CINE).

RESULTS

A total of 41 patients (26 men and 15 women) underwent all three tests within 1 week. Resting ejection fraction using each modality was assessed in a linear regression model to assess inter-test correlation with the other two modalities. Correlation between CINE and EBT was high (r = 0.90, intercept 4.67, p < 0.001). Similarly, correlation of CINE and RNA (r = 0.87, intercept -5.48, p < 0.001) and between EBT and RNA (r = 0.87, intercept -4.6, p < 0.001) were high. In a subset of those patients with LVEF < or = 40%, correlation was consistently high between EBT and CINE. However, correlations were poor for the comparisons between RNA and CINE (r = 0.40), and between the RNA and EBT (r = 0.47). The mean differences of measured ejection fractions between each of the imaging modality were small. However, there was only modest agreement between each of the comparisons as measured using 95% confidence interval (CI) on Bland-Altman plots.

CONCLUSION

These data indicate that the LVEF results are comparable among EBT, RNA, and CINE and can be used interchangeably to assess ventricular function for LVEF > 40%. For LVEF < or = 40%, we demonstrated some disparate results between cine angiography and RNA and between EBT and RNA, indicating that CINE or EBT may provide more accurate assessment.

Diagnostic efficacy of SonoVue

SonoVue is a second-generation ultrasound contrast agent consisting of phospholipid-stabilized microbubbles filled with sulfur hexafluoride, with outstanding stability and resistance to pressure. The efficacy of SonoVue (0.5, 1, 2, 4 mL) was compared with Albunex (doses 0.08 and 0.22 mL/kg) in patients with suspected ischemic disease and suboptimal endocardial-border delineation on unenhanced echocardiography at rest. All the doses resulted in significantly greater increases compared with Albunex in left-ventricular endocardial-border delineation score as well as in the duration of clinically useful contrast effect. The utility of SonoVue in diagnosing ischemic heart disease was also evaluated during pharmacologic stress (arbutamine or dobutamine). SonoVue produced significant increases from baseline in endocardial-border delineation score both at rest and during pharmacologic stress. The possibility of detecting myocardial perfusion defects using SonoVue-enhanced power Doppler and gray-scale harmonic contrast echocardiography associated with continuous and intermittent imaging was assessed in patients with coronary artery disease. The results obtained were comparable with corresponding 99mTc sestamibi single-photon emission computed tomography images. An effective cardiovascular assessment of a patient should also include the evaluation of carotid vessels, intracranial circulation, and renal arteries. SonoVue provided significant improvements in the evaluation of the Doppler signal in terms of diagnosis agreement with reference imaging modality especially for intracranial vessels. The safety profile of SonoVue was evaluated in 1,406 patients. The incidence of adverse events was 10.4%, the great majority of which were of mild intensity and resolved without consequences.

Dobutamine echocardiography predicts functional outcome after revascularisation in patients with dysfunctional myocardium irrespective of the perfusion pattern on resting thallium-201 imaging

OBJECTIVE

To evaluate whether the predictive value of dobutamine echocardiography for assessing contractile reserve was altered by differing patterns of regional myocardial perfusion.

PATIENTS

31 consecutive patients with symptomatic congestive heart failure (left ventricular ejection fraction < 35%) caused by coronary artery disease.

SETTING

A district general hospital.

METHODS

Thallium-201 perfusion imaging and low dose dobutamine (5-15 microg/kg/min) echocardiography were performed and resting echocardiography was repeated three months after revascularisation. Perfusion pattern and systolic wall thickening were compared using a 12 segment left ventricular model.

RESULTS

Of the 273 severely dysfunctional segments, 106 (39%) showed a normal perfusion and 167 (61%) an abnormal pattern. After revascularisation, recovery occurred in 71 of the segments with a normal perfusion pattern, and in these a dobutamine response was observed in 61 (86%); recovery also occurred in 56 segments with a mild to moderate abnormality of perfusion, and in these a dobutamine response was seen in 46 (81%) (NS). After revascularisation, the positive and negative predictive values for recovery of dysfunctional segments, where the majority were abnormally perfused, were 88% and 86%, respectively. Systolic wall thickening score indices improved from (mean (SD)) 3.21 (0.58) to 2. 6 (0.66) (p < 0.001) after revascularisation in dobutamine responsive patients (n = 24) compared with patients who did not show a dobutamine response (2.86 (0.65) and 3.13 (0.56), p = 0.61, respectively).

CONCLUSIONS

Dobutamine echocardiography predicted improvement of dysfunctional myocardium after revascularisation irrespective of the resting perfusion pattern seen.

Role of Contrast Echocardiography for the Assessment of Left Ventricular Function

The endocardial border of the left ventricle is incompletely identified in at least 30% of patients at rest or during stress echocardiography during fundamental imaging. This may lead to inaccurate assessment of regional and global left ventricular function or may lead to further diagnostic imaging with another modality resulting in a higher cost of healthcare. The recent development of second generation ultrasound contrast agents has resulted in improved detection of endocardial border at rest and during stress fundamental echocardiography. This has been consistently shown in various clinical trials involving 702 patients using a new contrast agent, SonoVuetrade mark. Other studies with contrast agents have also shown improved accuracy for determining left ventricular ejection fraction and volumes. Although unenhanced tissue harmonic imaging itself improved the assessment of left ventricular function, contrast enhanced harmonic imaging has recently been shown to be more accurate; however, larger clinical studies are required to establish the value of harmonic contrast imaging for the assessment of left ventricular function.

Myocardial viability on echocardiography predicts long-term survival after revascularization in patients with ischemic congestive heart failure

OBJECTIVES

This study was conducted to evaluate the effect of revascularization on survival in patients with congestive heart failure (CHF) due to ischemic left ventricular (LV) systolic dysfunction based on the presence of myocardial viability (MV).

BACKGROUND

There are insufficient data regarding the survival benefit of revascularization in patients with CHF due to ischemic LV systolic dysfunction.

METHODS

Follow-up was obtained in 87 consecutive patients with CHF due to ischemic LV systolic dysfunction (New York Heart Association [NYHA] class II-IV; LV ejection fraction <0.35) who underwent low-dose dobutamine echocardiography (DE). MV within each of 12 myocardial segments representing the LV was defined as having either: 1) normal function or mild dyssynergy at rest; 2) severe resting dyssynergy that improved on DE, or 3) worsening of function on DE except in the case of akinesia.

RESULTS

At a mean follow-up of 40+/-17 months, 37 patients had received revascularization on the basis of clinical grounds, and there were 22 (25%) cardiac-related deaths. Multivariate Cox regression analysis revealed that when patients with at least five segments showing MV underwent revascularization, mortality was reduced by an average of 93% (confidence interval of 22% to 99%), which was associated with improvement in NYHA class as well as LV ejection fraction. Patients with less than five segments showing MV who underwent revascularization (and thus, showing mostly scar), and those with at least 5 segments demonstrating MV who were treated medically, had a much higher mortality.

CONCLUSIONS

Revascularization produces a clear survival benefit in patients with CHF due to ischemic LV systolic dysfunction who have a significant region of the LV demonstrating MV. These data may have wide-ranging implications in the management of patients with coronary artery disease whose main clinical presentation is CHF.

Independent prognostic value of the extent and severity of systolic wall thickening abnormality at infarct site after thrombolytic therapy

BACKGROUND

The prognostic value of systolic wall thickening abnormality after acute myocardial infarction in the thrombolytic era is not clearly known.

METHODS AND RESULTS

Accordingly, 119 consecutive patients with acute myocardial infarction who underwent thrombolysis were investigated with exercise electrocardiography and rest echocardiography at predischarge evaluation and were followed up for cardiac events. During a mean follow-up period of 19 months, 43 patients had cardiac events. Multivariate analysis with clinical, exercise electrocardiographic, and rest echocardiographic parameters showed that the independent predictors of cardiac events were systolic wall thickening score at the site of infarct (p = 0.02), end-systolic volume (p = 0.03), and exercise time (p = 0.02). The only independent predictor for both recurrent ischemic (death, unstable angina, and reinfarction) and nonischemic events (congestive heart failure and ventricular tachycardia) was systolic wall thickening score at the site of infarct (p = 0.02 and p = 0.007, respectively).

CONCLUSIONS

Systolic wall thickening abnormality at rest is an important independent predictor of cardiac events in patients who have undergone thrombolysis after acute myocardial infarction.

Left ventricular atrioventricular plane displacement: an echocardiographic technique for rapid assessment of prognosis in heart failure

OBJECTIVE

To assess the prognostic value of atrioventricular plane displacement in heart failure patients.

DESIGN

Patients were followed prospectively for one year after atrioventricular plane displacement determination.

SETTING

Malmö University Hospital, with a primary catchment area of 250,000 inhabitants.

PATIENTS

181 patients with a clinical diagnosis of heart failure; age 75.7 (SD 5.2) years, duration of heart failure 2.7 (5.7) years; 100 men, 81 women.

MAIN OUTCOME MEASURES

Mortality in relation to atrioventricular plane displacement.

RESULTS

Total mortality was 22.7% (41/181), and was highly significantly (P = 0.001) related to atrioventricular plane displacement. Mortality within prospectively defined categories of displacement was: > or = 10.0 mm, 0% (0/19); 8.2 to 9.9 mm, 10.3% (3/29); 6.4 to 8.1 mm, 19.4% (12/62); and < 6.4 mm, 36.6% (26/71). The groups were similar in age, sex, angiotensin converting enzyme inhibitor and beta blocker treatment, and cause and duration of heart failure.

CONCLUSIONS

Mortality in heart failure is strongly related to atrioventricular plane displacement.

Beneficial effects of intravenous and oral carvedilol treatment in acute myocardial infarction. A placebo-controlled, randomized trial

BACKGROUND

Evidence of efficacy and safety of beta-blockers after thrombolysis for acute myocardial infarction (AMI) is equivocal. Newer beta-blockers such as carvedilol have not been tested in this setting.

METHODS AND RESULTS

This study investigated the effects of acute (intravenous) and long-term (6 months, oral) treatment with carvedilol versus placebo in 151 consecutive patients with AMI. Exercise ECG, ambulatory monitoring, and two-dimensional echocardiography were performed before hospital discharge and at 3 and 6 months. All patients were followed up and cardiovascular events recorded. The Cox proportional hazards model was used to compare time from randomization with the occurrence of a cardiovascular event, and Kaplan-Meier survival curves were calculated. Carvedilol was found to be safe, and it significantly reduced cardiac events compared with placebo (18 on carvedilol and 31 on placebo, P < .02). Fifty-four patients had heart failure at study entry; 34 received carvedilol. There were no adverse effects of carvedilol therapy and no excess events in this subgroup. Carvedilol produced significant reductions in heart rate (P < .0001), blood pressure (P < .005) at rest, and rate-pressure product at peak exercise (P < .003), but exercise capacity was unchanged. Left ventricular ejection fraction was not altered significantly by carvedilol, but stroke volume was higher at pre-hospital discharge examination (63 versus 53 mL; P < .01). Diastolic filling of the left ventricle (E/A ratio) was also improved (1.2 versus 0.9; P < .001). In a subgroup with left ventricular ejection fraction < 45% (n = 49 patients; 24 on carvedilol and 25 on placebo), carvedilol showed attenuation of remodeling.

CONCLUSIONS

Carvedilol was well tolerated and safe to use in patients immediately after AMI, including those with heart failure, and significantly improved outcome.

Prevalence, clinical features and prognosis of diastolic heart failure: an epidemiologic perspective

Numerous reports suggest that about one-third of patients with congestive heart failure do not have any abnormality of left ventricular systolic function. These patients presumably have heart failure on the basis of ventricular diastolic dysfunction. Our objective was to develop a comprehensive overview of published reports of the prevalence, clinical features and prognosis of diastolic heart failure and to offer recommendations for future studies. Thirty-one studies of patients with congestive heart failure with normal left ventricular systolic function were published in the time period from January 1970 through March 1995. These studies were identified with the use of computer-based searches in relevant data bases. Among patients with congestive heart failure, the prevalence of normal ventricular systolic performance in the published reports varies widely from 13% to 74%; the reported annual mortality rate also varies from 1.3% to 17.5%. The criteria for congestive heart failure, its chronicity and the age of the study sample affect the reported prevalence and prognosis of the disorder. The clinical signs and symptoms of diastolic heart failure are similar to those of patients with systolic heart failure, underscoring the need for evaluation of ventricular systolic function in patients with congestive heart failure. In the absence of any large-scale randomized clinical trial targeting these patients, the optimal treatment of diastolic heart failure is unclear. We conclude that the heterogeneity in previous studies of diastolic heart failure hinders the comparison of published reports. There is a need to conduct prospective, community-based investigations to better characterize the incidence, prevalence and natural history of diastolic heart failure. Randomized clinical trials are needed to determine optimal treatment strategies.