Stress echocardiography in the district hospital setting: a cost-saving analysis

AIMS

Accurate and cost-effective techniques are required for investigating patients experiencing chest pain, given the significant workload this patient cohort represents. We determined the cost impact of stress echocardiography compared with myocardial perfusion scintigraphy and coronary angiography in the investigation of patients with chest pain deemed unsuitable for exercise treadmill testing.

METHODS AND RESULTS

A total of 200 patients with chest pain-with a low-intermediate probability of coronary artery disease-consecutively referred for stress echocardiography were recruited. Referring clinicians were asked which management strategy they would have chosen were the stress echocardiography service unavailable. The cost saving of stress echocardiography, an accuracy analysis, and adverse outcomes at 6 and 24 months follow-up were determined. The total cost attributable to the stress echocardiography service was Pound Sterling 58 368. If unavailable, 78 (39%) patients would have been referred for angiography and 122 (61%) for perfusion scintigraphy at a cost of Pound Sterling 56 316 and Pound Sterling 42 090, respectively, with a total cost of Pound Sterling 98 406. This represents a cost saving of Pound Sterling 40 038.

CONCLUSION

Stress echocardiography is a cost saving method for the investigation of chest pain in patients with low-intermediate risk of flow limiting coronary artery disease in the district hospital setting.

Temporo-mandibular joint dislocation: an unusual complication of transoesophageal echocardiography

Temporo-mandibular joint (TMJ) dislocation is an unusual complication of transoesophageal echocardiography (TEE). We report a rare case of bilateral TMJ dislocation in an 84-year-old man prior to DC cardioversion (DCCV) for atrial flutter. Shortly after TEE and DCCV, the patient complained of bilateral facial pain. An orthopantomogram revealed bilateral TMJ dislocation. A closed reduction was performed by maxillo-facial surgeons under intravenous anaesthesia. Although very uncommon, the physician should be aware of the complication and its management.

The utility of volunteer home-visiting support to prevent maternal depression in the first year of life

BACKGROUND

Maternal depression can be detrimental to infant development. Structured home visiting initiated either in pregnancy or soon after the birth by a professional has led to better outcomes for mothers and their children but some vulnerable families may respond more favourably to a local volunteer. The value of volunteer support provided in the UK by Home-Start for maternal well-being is noted in qualitative studies, but there is no evidence of its impact from trials. The support is not structured and both the frequency and content of visits may vary.

METHODS

A cluster randomized study allocated Home-Start local schemes to intervention or control conditions. Mothers in all areas were screened at routine health checks in late pregnancy. In intervention areas names of those scoring 9+ on the Social Disadvantage Screening Index were passed to Home-Start to be offered a volunteer. Not all those offered the support accepted the offer. In control areas no support was offered. Research assessments were conducted at 2 and 12 months. The outcomes were major or minor depression occurring between 2 and 12 months (Structured Clinical Interview for Diagnostic and Statistical Manual - Third Edition - Revised) and depression symptoms at 12 months (Edinburgh Postnatal Depression Scale). Three groups were compared: supported, case-matched controls and those offered but not receiving support.

RESULTS

Almost one-third experienced depression during the time period. Volunteer support had no identifiable impact on the emergence of maternal depression from 2 to 12 months or on depression symptoms when infants were 12 months. The major predictor of both was depression identified at 2 months.

CONCLUSIONS

It was not found that informal support initiated following screening for disadvantage in pregnancy reduced the likelihood of depression for mothers with infants.

Comparison between myocardial contrast echocardiography and (99m)technetium sestamibi single photon emission computed tomography determined myocardial viability in predicting hard cardiac events following acute myocardial infarction

The extent of residual myocardial viability (MV) after acute myocardial infarction (AMI) is an important determinant of the outcome. Single photon emission computed tomography (SPECT) is widely used to assess MV after an AMI. However, myocardial contrast echocardiography (MCE), a relatively new technique for the assessment of MV, has better spatial and temporal resolution than SPECT. The present study evaluated whether MV determined by MCE is comparable to that determined using SPECT for the prediction of hard cardiac events after an AMI. Accordingly, 99 patients who had undergone simultaneous rest low-power MCE and nitrate-enhanced SPECT 7 days after an AMI were followed up for cardiac death and AMIs. Both MCE perfusion (1 = normal; 2 = reduced; and 3 = absent) and SPECT tracer uptake (0 = normal; 1 = mildly reduced; 2 = moderately reduced; 3 = severely reduced; and 4 = absent) were scored on a 16-segment left ventricular model. The contrast perfusion index and SPECT perfusion index were calculated by adding the respective scores in the 16 segments and dividing by 16. The contrast perfusion index and SPECT perfusion index were used as a measure of the residual MV on MCE and SPECT, respectively. Of the 99 patients recruited, 95 were available for the follow-up examination (follow-up 46 +/- 16 months). A total of 15 events (16%) occurred (8 cardiac deaths and 7 AMIs). Of the clinical, biochemical, echocardiographic, and SPECT markers of prognosis, the only independent predictors of cardiac death and cardiac death or AMI were age and MV as determined by MCE (p = 0.01 and p = 0.002, respectively). In conclusion, MV determined by MCE at rest was superior to nitrate-enhanced SPECT for the prediction of hard cardiac events after AMI.

Myocardial fibrosis in an veteran endurance athlete

This study reports the cardiac structure and function of a lifelong male endurance athlete, who has run over 148 000 miles, who presented with symptoms of chest discomfort, dyspnoea and loss of competitive running performance. Importantly, the athlete documented several periods of regular intensive endurance activity while suffering with flu-like symptoms. Cardiovascular MRI demonstrated a pattern of late gadolinium enhancement, which indicated myocardial scarring as a result of previous myocarditis.Myocarditis is a non-ischaemic inflammatory disease of the myocardium associated with cardiac dysfunction and arrhythmogenic substrate. The clinical course of viral myocarditis is mostly insidious with limited cardiac inflammation and dysfunction. However, as in the present case, overwhelming inflammation may occur in a subset of patients leading to myocardial fibrosis due to recurrent inflammation.

An update on contrast echocardiography

Ultrasound contrast agents, used with contrast-specific imaging techniques, have an established role for diagnostic cardiovascular imaging in the echocardiography laboratory. The advent of tissue harmonic imaging, albeit a significant advancement in ultrasound technology, still fail to produce diagnostically useful images in a significant proportion of patients. This therefore, often leads to inaccurate assessment of left ventricular function, neccesitating the use of other more laborious and expensive imaging techniques purely for diagnostic purposes. Historically, contrast agents have not been an integral component of the echocardiography imaging laboratory. However the need for a more robust method for the assessment of left ventricular function facilitated the developement of a unique class of contrast agents composed of microbubbles, which together with ultrasound, produce opacification of the left ventricular cavity, thus enabling accurate quantification of its function. The use of these contrast agents have now gone beyond the assessment of wall motion and function to the assessment of myocardial perfusion. Myocardial contrast echocardiography has enabled the assessment of cardiac anatomy, function and perfusion, all in one sitting, by the bedside. Contrast ultrasound imaging has now been applied to even newer techniques such as real-time three-dimensional echocardiography and is also showing promise in the assessment of carotid ultrasound for intima-media thickness. Contrast agents therefore have a significant role in cardiovascular diagnostics and its use can only improve patient care.

Ethnicity-related differences in left ventricular function, structure and geometry: a population study of UK Indian Asian and European white subjects

OBJECTIVES

The authors studied healthy UK Indian Asian and European white subjects to assess whether functional, structural and geometrical properties of the left heart are intrinsically related to ethnicity.

BACKGROUND

Quantitative assessment of cardiac function and structure is necessary to diagnose heart failure syndromes and is validated to refine risk prediction. A better understanding of the demographic factors that influence these variables is required.

METHODS

458 healthy subjects were recruited from the London Life Sciences Prospective Population (LOLIPOP) study. They underwent 2-D and tissue Doppler echocardiography for quantification of left ventricular (LV) function, LV volumes, left atrial volume index (LAVI), left ventricular mass index (LVMI) and relative wall thickness (RWT).

RESULTS

Indian Asians had attenuated mitral annular systolic velocity (8.9 cm/s vs 9.5 cm/s, p<0.001), lower mitral annular early diastolic velocity (10.3 cm/s vs 11.0 cm/s, p<0.001) and higher E/Ea ratio (7.9 vs 7.0, p<0.001) compared to European white subjects. Although Indian Asians had significantly smaller left heart volumes and LVMI, they had a significantly higher RWT (0.37 vs 0.35, p<0.001). After adjustment for covariates, these ethnicity-related differences remained highly significant (p<0.001).

CONCLUSION

Compared to European white people, Indian Asians had attenuated longitudinal LV function, higher LV filling pressure and demonstrated a greater degree of concentric remodelling independent of other demographic and clinical parameters.

Safety of contrast in stress echocardiography in stable patients and in patients with suspected acute coronary syndrome but negative 12-hour troponin

Limited studies are available demonstrating the safety of contrast agents in patients undergoing stress echocardiography and none in patients with suspected acute coronary syndrome (ACS). Therefore, we sought to assess the safety profile of contrast agents in patients with stable chest pain and in those with suspected ACS (nondiagnostic electrocardiogram and negative initial 12-hour cardiac troponin test results). During a 4-year period, 3,704 patients underwent stress echocardiography (exercise or dobutamine), of whom, 929 (25%) had suspected ACS. Contrast agents (SonoVue 46%, Luminity 54%) were used in 1,150 patients (31%). No patients died with or without contrast administration. No nonfatal acute myocardial infarction occurred in patients administered contrast agents compared with 3 cases of acute myocardial infarction in the noncontrast group (p = 0.24). Two cases of sustained ventricular tachycardia developed, one in each group (p = 0.98). Compared with those who did not receive contrast, patients in both the stable chest pain and the suspected ACS groups had a greater burden of cardiovascular risk factors. The left ventricular function at rest was significantly worse in the patients who received contrast than in those who did not in the suspected ACS group. Also, a greater ischemic burden was present in those receiving contrast than in those not receiving it in both the stable chest pain and the suspected ACS groups. In conclusion, despite the presence of greater risk features compared with patients undergoing unenhanced stress echocardiography, the administration of ultrasound contrast agents (SonoVue and Luminity) in those with stable chest pain and those with suspected ACS was not associated with excess adverse events.

Quantitative myocardial contrast echocardiography during pharmacological stress for diagnosis of coronary artery disease: a systematic review and meta-analysis of diagnostic accuracy studies

AIMS

We conducted a meta-analysis to evaluate the accuracy of quantitative stress myocardial contrast echocardiography (MCE) in coronary artery disease (CAD).

METHODS AND RESULTS

Database search was performed through January 2008. We included studies evaluating accuracy of quantitative stress MCE for detection of CAD compared with coronary angiography or single-photon emission computed tomography (SPECT) and measuring reserve parameters of A, beta, and Abeta. Data from studies were verified and supplemented by the authors of each study. Using random effects meta-analysis, we estimated weighted mean difference (WMD), likelihood ratios (LRs), diagnostic odds ratios (DORs), and summary area under curve (AUC), all with 95% confidence interval (CI). Of 1443 studies, 13 including 627 patients (age range, 38-75 years) and comparing MCE with angiography (n = 10), SPECT (n = 1), or both (n = 2) were eligible. WMD (95% CI) were significantly less in CAD group than no-CAD group: 0.12 (0.06-0.18) (P < 0.001), 1.38 (1.28-1.52) (P < 0.001), and 1.47 (1.18-1.76) (P < 0.001) for A, beta, and Abeta reserves, respectively. Pooled LRs for positive test were 1.33 (1.13-1.57), 3.76 (2.43-5.80), and 3.64 (2.87-4.78) and LRs for negative test were 0.68 (0.55-0.83), 0.30 (0.24-0.38), and 0.27 (0.22-0.34) for A, beta, and Abeta reserves, respectively. Pooled DORs were 2.09 (1.42-3.07), 15.11 (7.90-28.91), and 14.73 (9.61-22.57) and AUCs were 0.637 (0.594-0.677), 0.851 (0.828-0.872), and 0.859 (0.842-0.750) for A, beta, and Abeta reserves, respectively.

CONCLUSION

Evidence supports the use of quantitative MCE as a non-invasive test for detection of CAD. Standardizing MCE quantification analysis and adherence to reporting standards for diagnostic tests could enhance the quality of evidence in this field.

Contrast echocardiography: an update

Despite the advent of tissue harmonic imaging, echocardiography fails to produce diagnostically useful images in a significant proportion of patients. This often leads to inaccurate assessment of left ventricular function, necessitating the use of other, more expensive and laborious imaging techniques, purely for diagnostic purposes. This has facilitated the development of microbubbles, which together with ultrasound, produce opacification of the left ventricular cavity, thus enabling clear visualization and accurate quantification of left ventricular function. Contrast agents have also facilitated the development of myocardial contrast echocardiography. This allows assessment of cardiac anatomy, function, and perfusion, all in one sitting, by the bedside. Contrast ultrasound imaging also has now been applied to newer techniques (eg, real-time three-dimensional echocardiography) and is also showing promise in other cardiovascular scans (eg, carotid ultrasound for intima-media thickness). Thus, contrast agents play a pivotal role in noninvasive cardiovascular imaging and its use worldwide is likely to increase.