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Biomedical subjects

Roxy Senior

Publications and source records attributed to Roxy Senior.

At least 37 records · Page 2Linked to original sources
PubMed2005

Myocardial contrast echocardiography for the detection of coronary artery stenosis: a prospective multicenter study in comparison with single-photon emission computed tomography.

OBJECTIVES: The purpose of this study was to compare myocardial contrast echocardiography (MCE) with single-photon emission computed tomography (SPECT) for the detection of significant coronary artery disease (CAD) in patients with symptoms suggestive of CAD. BACKGROUND: Single-photon emission computed tomography is a well-established method of assessing patients with CAD. Myocardial contrast echocardiography is a new technique allowing bedside assessment of myocardial perfusion. We hypothesized that MCE was comparable to SPECT in the assessment of patients with known or suspected CAD. METHODS: A total of 123 patients scheduled for coronary angiography underwent intermediate (mechanical index 0.5) triggered replenishment MCE and SPECT imaging at rest and after vasodilator stress. Coronary angiography was performed within four weeks of stress imaging. RESULTS: In total, 96 of 123 (78%) patients demonstrated CAD (stenosis >/=50%). There was no difference in the sensitivity of MCE compared with SPECT in the detection of CAD (84% vs. 82%; p = NS), and both demonstrated similar specificity (56% vs. 52%, respectively). In patients with multivessel disease, MCE and SPECT also demonstrated similar sensitivity (91% and 88%, respectively) for the detection of CAD. Agreement between MCE and SPECT for the presence or absence of CAD was 73%. CONCLUSIONS: Myocardial contrast echocardiography is comparable to SPECT in the detection of CAD not only on a patient basis but also in the localization of disease by vascular territory in a relatively high-risk population.

Contrast Media↗
PubMed2005

What is the most cost-effective strategy to screen for left ventricular systolic dysfunction: natriuretic peptides, the electrocardiogram, hand-held echocardiography, traditional echocardiography, or their combination?

AIMS: To assess the screening characteristics and cost-effectiveness of screening for left ventricular systolic dysfunction (LVSD) in community subjects. METHODS AND RESULTS: A total of 1392 members of the general public and 928 higher risk subjects were randomly selected from seven community practices. Attending subjects underwent an ECG, N-terminal pro-brain natriuretic peptide (NTproBNP) serum levels, and traditional echocardiography (TE). A total of 533 consecutive subjects underwent hand-held echocardiography (HE). The screening characteristics and cost-effectiveness (cost per case of LVSD diagnosed) of eight strategies to predict LVSD (LVSD <45% on TE) were compared. A total of 1205 subjects attended. Ninety six per cent of subjects with LVSD in the general population had identifiable risk factors. All screening strategies gave excellent negative predictive value. Screening high-risk subjects was most cost-effective, screening low-risk subjects least cost-effective. TE screening was the least cost-effective strategy. NTproBNP screening gave similar cost savings to ECG screening; HE screening greater cost-savings, and HE screening following NTproBNP or ECG pre-screening the greatest cost-savings, costing approximately 650 Euros per case of LVSD diagnosed in high-risk subjects (63% cost-savings vs.TE). CONCLUSION: Thus several different modalities allow cost-effective community-based screening for LVSD, especially in high-risk subjects. Such programmes would be cost-effective and miss few cases of LVSD in the community.

Adolescent↗
PubMed2005

Myocardial contrast echocardiography for distinguishing ischemic from nonischemic first-onset acute heart failure: insights into the mechanism of acute heart failure.

BACKGROUND: Distinguishing ischemic from nonischemic origin in patients presenting with acute heart failure (AHF) not resulting from acute myocardial infarction has both therapeutic and prognostic implications. The aim of the study was to assess whether myocardial contrast echocardiography (MCE) can identify underlying coronary artery disease (CAD) as the cause of AHF. METHODS AND RESULTS: Fifty-two consecutive patients with AHF with no prior clinical history of CAD and no clinical evidence of acute myocardial infarction underwent resting echocardiography and MCE both at rest and after dipyridamole stress at a mean of 9+/-2 days after admission. All patients underwent coronary arteriography before discharge. Of the 52 patients, 22 demonstrated flow-limiting CAD (>50% luminal diameter narrowing). Sensitivity, specificity, and positive and negative predictive values of MCE for the detection of CAD were 82%, 97%, 95%, and 88%, respectively. Among clinical, ECG, biochemical, resting echocardiographic, and MCE markers of CAD, MCE was the only independent predictor of CAD (P<0.0001). Quantitative MCE demonstrated significantly (P<0.0001) lower myocardial blood flow velocity reserve in vascular territories subtended by >50% CAD (0.59+/-0.46) compared with patients with normal coronary arteries (1.99+/-1.00). However, myocardial blood flow velocity reserve in patients with no significant CAD was significantly (P=0.03) lower compared with control (2.91+/-0.41). Myocardial blood flow velocity reserve correlated significantly (P<0.0001) with increasing severity of CAD. CONCLUSIONS: MCE, which is a bedside technique, may be used to detect CAD in patients presenting with AHF without a prior history of CAD or evidence of acute myocardial infarction. Quantitative MCE may further risk-stratify patients with AHF but no CAD.

Acute Disease↗
PubMed2005

Increased left atrial volume index is an independent predictor of raised serum natriuretic peptide in patients with suspected heart failure but normal left ventricular ejection fraction: Implication for diagnosis of diastolic heart failure.

BACKGROUND: Left atrial volume index (LAVI) is increasingly recognised as a relatively load-independent marker of left ventricular (LV) filling pressures. We assessed the capacity of LAVI to predict LV diastolic dysfunction in comparison with N-terminal pro B-type natriuretic peptide (NTproBNP) in patients with suspected heart failure and a normal ejection fraction (EF). METHODS: 137 patients with suspected heart failure (HF), referred from the community for echocardiography, prospectively underwent Doppler echocardiography, LAVI and NTproBNP estimation. Raised LAVI and reduced LV systolic function were defined as >26 ml/m2 and LV EF <50% respectively. RESULTS: Of 137 patients, 21 were excluded (2 with significant mitral valve disease and 19 with atrial fibrillation). Of the remaining 116 subjects, 92 showed normal LV systolic function. The univariate predictors of serum log NTproBNP were age (p < 0.001), LA dimension (p = 0.001), LAVI (p < 0.001), A wave (p = 0.001), E:A (p = 0.07) and septal wall thickness (p = 0.004). However on multivariate analysis, LAVI was found to be the most consistent and significant predictor of NTproBNP. The area under the curve of the receiver operating characteristic (ROC) curve for NTproBNP in detecting patients with LVEF > or = 50% and LAVI >26 ml/m2 was 0.81 (p < 0.0001) and for patients with LAVI > 26 ml/m2 with and without LVEF > or = 50% was 0.82 (p < 0.0001). CONCLUSION: This data confirms that LAVI on resting echocardiography, specifically in patients with suspected HF and normal LV systolic function is a powerful independent predictor of LV diastolic dysfunction as predicted by serum NTproBNP. In a population with a high suspicion of diastolic heart failure, LAVI may significantly contribute to diagnostic precision.

Aged↗
PubMed2005

What is the normal range for N-terminal pro-brain natriuretic peptide? How well does this normal range screen for cardiovascular disease?

AIMS: To define the N-terminal pro-brain natriuretic peptide (NTpBNP) normal range, assessing its cardiovascular screening characteristics in general population and higher risk subjects. METHODS AND RESULTS: A total of 2320 subjects (1392 general population and 928 high-risk) > or =45 years old, selected randomly from seven community practices, were invited to undergo clinical assessment and echocardiography and to assess NTpBNP serum levels. Of these, 1205 attended. The NTpBNP normal range was calculated and its cardiovascular screening characteristics were assessed. Age (P<0.0001) and female gender (P<0.0001) independently predicted NTpBNP levels in normal subjects. In the general population, age- and gender-stratified normal NTpBNP levels gave a negative-predictive value (NPV) of 99% in excluding left ventricular systolic dysfunction, atrial fibrillation, and valvular heart disease, and a positive predictive value of 56% in detecting any cardiovascular disease assessed. In high-risk subjects, these values were 98 and 62%, respectively. Ninety-five per cent of subjects with NTpBNP levels over four times the normal had significant cardiovascular disease with the others having renal dysfunction. CONCLUSION: Normal NTpBNP levels should be stratified by age and gender. Normal NTpBNP levels give high NPV in excluding significant cardiovascular disease. Most subjects with raised NTpBNP levels and almost all subjects with NTpBNP levels over four times the normal have significant cardiovascular disease.

Age Distribution↗
PubMed2005

Stress echocardiography is superior to exercise ECG in the risk stratification of patients presenting with acute chest pain with negative Troponin.

OBJECTIVE: To compare exercise electrocardiography (ExECG) and stress echocardiography (SE) in the risk stratification of patients presenting to hospital with cardiac-sounding chest pain, non-diagnostic ECGs and negative cardiac Troponin. METHODS: Patients presenting with acute chest pain were prospectively randomised to early ExECG or SE. A post-test likelihood of CAD was determined by the pre-test likelihood and the result of the stress test. Patients with a low post-test likelihood of CAD were discharged; those with a high post-test probability were considered for coronary angiography. All others were managed according to standard hospital protocols. RESULTS: A total of 302 patients underwent either ExECG or SE. SE identified significantly more patients with a low post-test probability of CAD (80% vs 31%, p<0.0001) and significantly fewer patients with an intermediate post-test likelihood of CAD compared to ExECG (3% vs 47%; p<0.0001). Significantly fewer patients undergoing SE were referred for further tests to exclude or refute the diagnosis of CAD (16% vs 52%; p<0.0001). In total, 36 (12%) had flow limiting CAD demonstrated by coronary angiography. Significant CAD was seen in fewer patients with a positive ExECG than with a positive SE (56% vs 84% (p=0.12)). Event rates were low for both modalities in patients with low post-test probability (3.5% for SE vs 5.1% for ExECG; p=ns) though the number of patients identified as low risk was higher if SE was performed. CONCLUSION: Despite negative cardiac Troponin, 12% of patients with acute chest pain had significant CAD. SE is superior to ExECG in discriminating between those patients with a low and intermediate risk of CAD and correctly identified patients with significant CAD, as well as conferring an excellent prognosis in those considered low risk. SE significantly reduces the requirement for further tests to diagnose CAD compared to ExECG.

Analysis of Variance↗
PubMed2005

Myocardial contrast echocardiography accurately reflects transmurality of myocardial necrosis and predicts contractile reserve after acute myocardial infarction.

BACKGROUND: Both myocardial contrast echocardiography (MCE) and cardiovascular magnetic resonance (CMR) can identify myocardial necrosis after acute myocardial infarction (AMI). However, transmural extent of infarction (TEI) correlates of myocardial perfusion by MCE after AMI are unknown. We sought to ascertain the ability of MCE to (1) predict TEI as defined by contrast-enhanced CMR and (2) to compare the relative accuracy of these techniques to predict contractile reserve late after AMI. METHODS: MCE and CMR were performed in 42 patients with AMI 7 to 10 days after thrombolysis. Contractile reserve with low-dose dobutamine was evaluated 12 weeks after revascularization. RESULTS: Both qualitative (myocardial contrast intensity) and quantitative MCE [peak contrast intensity, microbubble velocity (beta), and myocardial blood flow] showed a significant (P < .0001) inverse relationship with increasing TEI. However, beta was the single best predictor of TEI (P = .002). Both qualitative MCE and CMR predicted contractile reserve similarly (area under receiver operating characteristic curve were 0.84 and 0.80, respectively). Qualitative and quantitative MCE parameters as well as CMR correlated significantly with the degree of contractile reserve (P < .001). Multiple logistic regression analysis using clinical, electrocardiographic, MCE, and CMR parameters showed that both MCE (OR = 0.03, 95% CI 0.01-0.10, P < .001) and CMR (OR = 0.11, 95% CI 0.04-0.26, P < .001) are independent predictors of contractile reserve. The most discriminative quantitative parameters for prediction of contractile reserve were microbubble velocity (P < .001) and myocardial blood flow (P = .001) assessed by MCE. CONCLUSION: MCE reflects the transmural extent of AMI as assessed by CMR. Both techniques predict contractile reserve.

Echocardiography↗
PubMed2005

The use of hand-carried ultrasound in the hospital setting--a cost-effective analysis.

OBJECTIVES: We sought to assess the accuracy of hand-carried ultrasound (HCU) in the prediction of a normal study, and its cost-effectiveness in reducing the number of standard departmental echocardiograms (SDE) performed on hospital inpatients. METHODS: The setting was a district general hospital. Participants were 157 consecutive inpatients, mean age 68 (range: 18-97) years, 95 men (61%), referred for SDE. HCU was performed at the bedside as part of the clinical assessment. SDE was performed routinely. Main outcome measures were: (1) assessment of the accuracy of HCU in detection of a normal or abnormal study as determined by SDE; and (2) a cost-effectiveness analysis. RESULTS: Indications for echocardiography were: left ventricular (LV) function assessment, n = 101 (64.3%); valvular abnormalities, n = 11 (7%); arrhythmia, n = 4 (2.6%); miscellaneous, n = 10 (6.4%); and no reason stated, 31 (19.7%). The sensitivity, specificity, and positive and negative predictive values of HCU predicting a completely normal scan were 74%, 96%, 94%, and 81%, respectively, and of predicting normal LV function in requests specific for LV function assessment were 81%, 100%, 100%, and 77%, respectively. If either all inpatients or those with requests for LV function assessment underwent HCU initially, and only those with abnormal scans underwent further SDE, there would be a 29% and 22% reduction in departmental workload and a cost saving of pound sterling 23,000 and pound sterling 30,000, respectively. CONCLUSION: HCU is an accurate method of identifying patients with normal hearts as determined by SDE. Its routine use is cost-effective and can significantly reduce the number of SDE that need be performed.

Adolescent↗
PubMed2005

Improved accuracy of low-power contrast echocardiography for the assessment of left ventricular remodeling compared with unenhanced harmonic echocardiography after acute myocardial infarction: comparison with cardiovascular magnetic resonance imaging.

BACKGROUND: Assessment of left ventricular (LV) remodeling after acute myocardial infarction (AMI) has both therapeutic and prognostic implications. Low-power contrast echocardiography (CE) has the advantage of simultaneously assessing myocardial perfusion and LV remodeling. OBJECTIVE: This study aimed to evaluate the accuracy of low-power CE to assess LV remodeling after AMI compared with unenhanced harmonic echocardiography (HE). METHODS: A total of 36 consecutive patients underwent HE, CE (SonoVue), and cardiovascular magnetic resonance (CMR) imaging 7 to 10 days after AMI. Left ventricular ejection fraction (LVEF), end-systolic volume (LVESV), and end-diastolic volume (LVEDV) were assessed. RESULTS: Absolute differences for LVESV and LVEDV between CMR and CE were significantly smaller than those between CMR and HE. CE estimate of LVEF more accurately classified patients into LVEF < 35%, 35% to 45%, and > 45% (agreement, 83%; kappa = 0.66 with CMR) compared with HE (agreement, 69%; kappa = 0.33 with CMR). CONCLUSIONS: Low-power CE is more accurate than HE for estimating LV remodeling after AMI.

Echocardiography↗
PubMed2005

Safety: the heart of the matter.

An integral part of evaluation of cardiac disease in modern day medicine is echocardiography. It has made great strides since the initial collaboration of Dr. Helmut Hertz and Dr. Inge Edler. In its modern day form, echocardiography maintains a legacy of a bedside utility while adopting many of the technologic advances ushered in by the digital era. As a result, it boasts a broad and growing spectrum of application including routine use in primary cardiac diagnosis and screening, therapeutic assessment, and guidance of interventional and surgical procedures. With the advent of ultrasound contrast agents it is now arguably the most complete 'one-stop' investigational tool to assess cardiac structure, function and perfusion. However, has it maintained its safety profile? The familiar and oft quoted dictum in medicine of "first do no harm" is of great importance for any diagnostic tool and patient safety should remain a primary consideration for any new investigational technique. In this issue Cosyns' et al. have examined whether some of the theoretical and in vitro experimental concerns surrounding myocardial injury during and following contrast echocardiography result in any detectable change in cardiac function.

Cardiomyopathies↗
PubMed2005

Clinical benefits of contrast-enhanced echocardiography during rest and stress examinations.

Despite the recent introduction of tissue harmonic imaging in echocardiography, 10-15% of patients have poor endocardial border definition. This may lead to erroneous assessment of regional and global left ventricular (LV) function or to further diagnostic imaging with another modality thus increasing the costs for the healthcare system. The recent development of second generation contrast echocardiography agents such as SonoVue has resulted in several studies showing the value of these agents to outline endocardium clearly, thereby improving assessment of LV function. The use of these contrast agents has also opened the possibility of automated and quantitative LV function assessment, making it more accurate and reproducible. Other major clinical uses of these contrast agents are evaluation of LV masses such as thrombus and tumors, and better definition of LV structure such as delineating LV aneurysm, pseudoaneurysm; and non-compaction of LV and apical cardiomyopathy. Furthermore, the use of these contrast agents during stress not only improved the assessment of wall motion but also made possible the evaluation of myocardial perfusion, thereby increasing diagnostic accuracy for the detection of coronary artery disease.

Echocardiography↗
PubMed2004

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).

Cardiomyopathy, Dilated↗
PubMed2004

The pathologic basis of Q-wave and non-Q-wave myocardial infarction: a cardiovascular magnetic resonance study.

OBJECTIVES: The purpose of this study was to determine the pathologic basis of Q-wave (QW) and non-Q-wave (NQW) myocardial infarction (MI). BACKGROUND: The QW/NQW distinction remains in wide clinical use but the meaning of the difference remains controversial. We hypothesized that measurement of total MI size and transmural extent by late gadolinium enhancement cardiovascular magnetic resonance (CMR) would identify the pathologic basis of QWs. METHODS: A total of 100 consecutive patients with documented previous MI had electrocardiogram and CMR on the same day. Patients with acute MI within seven days were excluded. Left ventricular function and the size and transmural extent of MI were quantified in the three major arterial territories and correlated with the presence of QW. RESULTS: Subendocardial MI showed QW in 28%. Transmural MI showed NQW in 29%. Of all MIs, 48% were at some point transmural, and 99% of these were at some point non-transmural. As MI size and number of transmural segments increased, the probability of QW increased (anterior: total size chi-square = 53, p < 0.0001, transmural extent chi-square = 36, p < 0.0001; inferior: total size chi-square = 16, p = 0.001, transmural extent chi-square = 10, p = 0.001). These findings did not hold for lateral MI. In a multivariate model, the transmural extent of MI was not an independent predictor of QW when total size of MI was removed. The QW/NQW classification was a good test for size of MI (area under receiver operating characteristic curve: anterior 0.90, inferior 0.77). CONCLUSIONS: The QW/NQW distinction is useful, but it is determined by the total size rather than transmural extent of underlying MI.

Adult↗
PubMed2004

Accuracy of dipyridamole myocardial contrast echocardiography for the detection of residual stenosis of the infarct-related artery and multivessel disease early after acute myocardial infarction.

OBJECTIVES: We aimed to evaluate the ability of vasodilator myocardial contrast echocardiography (MCE) to detect significant infarct-related artery (IRA) stenosis and multivessel disease (MVD) after thrombolysis. BACKGROUND: The detection of residual IRA stenosis subtending significant viable myocardium and the identification of MVD may help to triage patients who may benefit from mechanical revascularization after acute myocardial infarction (AMI) and thrombolysis. METHODS: Patients with AMI underwent low-power MCE at rest and after dipyridamole stress during SonoVue infusion seven to 10 days after thrombolysis. RESULTS: Of the 73 patients, 61 demonstrated significant myocardial viability, of whom 57 (93%) showed significant IRA stenosis. Sensitivities to detect >50% IRA stenosis and MVD were 88% and 72%, respectively. The accuracy of detecting significant coronary stenosis in the anterior (left anterior descending coronary artery) versus inferoposterior (right coronary artery/left circumflex artery) circulation was similar for both IRA (85% vs. 91%) and remote territories (91% vs. 81%). Quantitative peak contrast intensity (p = 0.02), microbubble velocity (p = 0.0001), and myocardial blood flow (p < 0.0001) were significantly lower in patients with significant coronary stenosis during dipyridamole compared with rest. Only beta reserve discriminated various grades of coronary stenosis. CONCLUSIONS: Use of MCE accurately predicted significant IRA stenosis and MVD after thrombolysis. This information is valuable for identifying patients who may benefit from mechanical revascularization.

Aged↗
PubMed2004

Usefulness of myocardial contrast echocardiography in predicting collateral blood flow in the presence of a persistently occluded acute myocardial infarction-related coronary artery.

Adequate collateral blood flow at rest can sustain myocardial viability despite persistent occlusion of the infarct-related artery (IRA) in acute myocardial infarction (AMI). This has therapeutic and prognostic implications. Studies addressing the value of intravenous myocardial contrast echocardiography (MCE) to detect collateral blood flow after AMI in humans are limited. Accordingly, 70 consecutive patients with AMI underwent low-power intravenous MCE using a Sonovue infusion 7 to 10 days after thrombolysis. Myocardial perfusion detected by MCE was analyzed (qualitatively and quantitatively) in the akinetic segments in 20 patients (29%) with an occluded IRA who subsequently underwent revascularization. Contractile reserve, which is a marker of myocardial viability, was assessed with low-dose dobutamine 12 weeks after mechanical revascularization. Of the 102 akinetic segments (32%), 37 (36%) showed contractile reserve. Contractile reserve was present in 24 of the 29 segments (83%) with homogenous contrast opacification and absent in 60 of the 73 segments (82%) with reduced/absent opacification. Quantitative peak contrast intensity, microbubble velocity, and myocardial blood flow were significantly higher (p <0.0001) in the segments with contractile reserve than in those without contractile reserve. Multiple logistic regression analysis using electrocardiographic, biochemical, and myocardial contrast echocardiographic markers of collateral blood flow showed that MCE (odds ratio 26.0, 95% confidence interval 6.3 to 108.0, p <0.001) was the only independent predictor of collateral blood flow as demonstrated by the presence of contractile reserve. MCE may thus be used as a reliable bedside technique for the accurate evaluation of collateral blood flow in the presence of an occluded IRA after AMI.

Collateral Circulation↗