A microcosting study of diagnostic tests for the detection of coronary artery disease in The Netherlands.

OBJECTIVE: The primary aim of the present study was to calculate the actual costs of four diagnostic tests for the detection of coronary artery disease in the Netherlands using a microcosting methodology. As a secondary objective, the cost effectiveness of eight diagnostic strategies was examined, using microcosting and reimbursement fees subsequently as the cost estimate. DESIGN: A multicenter, retrospective cost analysis from a hospital perspective. SETTING: The study was conducted in three general hospitals in the Netherlands for 2006. INTERVENTIONS: Exercise electrocardiography (exECG), stress echocardiography (sECHO), single-photon emission computed tomography (SPECT) and coronary angiography (CA). RESULTS: The actual costs of exECG, sECHO, SPECT and CA were 33, 216, 614 and 1300 euro respectively. For all diagnostic tests, labour and indirect cost components (overheads and capital) together accounted for over 75% of the total costs. Consumables played a relatively important role in SPECT (14%). Hotel and nutrition were only applicable to SPECT and CA. Diagnostic services were solely performed for CA, but their costs were negligible (2%). Using microcosting estimates, exECG-sECHO-SPECT-CA was the most and CA the least cost effective strategy (397 and 1302 euro per accurately diagnosed patient). Using reimbursement fees, exECG-sECHO-CA was most and SPECT-CA least cost effective (147 and 567 euro per accurately diagnosed patient). CONCLUSIONS: The use of microcosting estimates instead of reimbursement fees led to different conclusions regarding the relative cost effectiveness of alternative strategies.

Clinical utility and cost effectiveness of a personal ultrasound imager for cardiac evaluation during consultation rounds in patients with suspected cardiac disease.

OBJECTIVE: To assess the clinical utility and cost effectiveness of a personal ultrasound imager (PUI) during consultation rounds for cardiac evaluation of patients with suspected cardiac disease. METHODS: 107 unselected patients from non-cardiac departments (55% men) were enrolled in the study. After the physical examination the consultant cardiologist performed an echocardiographic study with a PUI. The final report was given instantly to the referring physician. All patients subsequently underwent a study with a standard echocardiographic device (SED). For each patient the consultant cardiologist noted whether the findings of the PUI were adequate for final diagnosis. The total cost when full echocardiography was used was compared with the cost when the PUI was used. The time interval from request to diagnosis was also compared. RESULTS: In 84 (78.5%) patients no further examination with an SED was regarded as necessary. Twenty three patients (21.5%) required a further detailed examination with the SED because of the need for haemodynamic information. There was an excellent agreement for the detection of abnormalities between the two devices (96%). The total cost was euro;132 per patient with the SED and euro;75 per patient with the PUI. According to this study, the use of the PUI can lead to a 33.4% reduction of total cost. The mean time from request to diagnosis at the authors' institution was four days for the SED and instantly for the PUI, for additional potential cost savings. CONCLUSIONS: Immediate echocardiographic assessment during consultation rounds can lead to significant cost savings and can shorten the time to diagnosis.

The apical long-axis rather than the two-chamber view should be used in combination with the four-chamber view for accurate assessment of left ventricular volumes and function.

BACKGROUND: Most biplane methods for the echocardiographic calculation of left ventricular volumes assume orthogonality between paired views from the apical window. Our aim was to study the accuracy of biplane left ventricular volume calculations when either the apical two-chamber or long-axis views are combined with the four-chamber view. The left ventricular volumes calculated from three-dimensional echocardiographic data sets were used as a reference. Twenty-seven patients underwent precordial three-dimensional echocardiography using rotational acquisition of planes at 2-degree intervals, with ECG and respiratory gating. End-diastolic and end-systolic left ventricular volumes and ejection fraction on three-dimensional echocardiography were calculated by (1) Simpson's methods (3DS) at 3 mm short-axis slice thickness (reference method) and by (2) biplane ellipse from paired views using either apical four- and two-chamber views (BE-A) or apical four- and long-axis views (BE-B). Observer variabilities were studied by the standard error of the estimate % (SEE) in 19 patients for all methods. RESULTS: The spatial angles (mean +/- SD) between the apical two-chamber, long-axis and four-chamber views were 63.3 degrees +/- 19.7 and 99.1 degrees +/- 25.6, respectively. The mean +/- SD of end-diastolic and end-systolic left ventricular volumes (ml) and ejection fraction (%) by 3DS were 142.2 +/- 60.9, 91.8 +/- 59.6 and 39.6 +/- 17.5, while that by BE-A were 126.7 +/- 60.4, 84.0 +/- 57.9 and 39 +/- 17 and by BE-B were 134.3 +/- 62.4, 88.6 +/- 59.7 and 39.1 +/- 16.7, respectively. BE-B intra-observer (8.4, 6.7 and 3.5) and inter-observer (9.8, 11.5 and 5.4) SEE for end-diastolic and end-systolic left ventricular volumes (ml) and ejection fraction (%), respectively, were smaller than that for BE-A (10.8, 8.8 and 4.1 and 11.4, 14.7 and 6.1, respectively). There was excellent correlation between 3DS and BE-A (r = 0.99, 0.98 and 0.98) and BE-B (0.98, 0.98 and 0.98) for calculating end-diastolic and end-systolic left ventricular volume and ejection fractions, respectively. There were no significant differences between BE-A and BE-B with 3DS for end-diastolic and end-systolic left ventricular volume and ejection fraction calculations (P = 0.2, 0.3 and 0.4 and P = 0.5, 0.5 and 0.4, respectively). There were closer limits of agreement (mean +/- 2 SD) between 3DS and BE-B 7.9 +/- 18.8, 3.2 +/- 14.2 and 0.8 +/- 5.8 than that between 3DS and BE-A 15.5 +/- 19.6, 7.8 +/- 16.2 and 1.1 +/- 7.4 for calculating end-diastolic and end-systolic left ventricular volume and ejection fractions, respectively. CONCLUSION: Both apical two-chamber and apical long-axis views are not orthogonal to the apical four-chamber view. Observer variabilities of BE-B were smaller than that for BE-A. BE-A and BE-B have excellent correlation and non-significant differences with 3DS for left ventricular volume and ejection fraction calculations. There were closer limits of agreement between BE-B with 3DS for left ventricular volume and ejection fraction calculations than that between BE-A and 3DS. Therefore, we recommend the use of the apical long-axis rather than the two-chamber view in combination with the four-chamber view for accurate biplane left ventricular volume and ejection fraction calculations.

Quantitative assessment of myocardial blood flow by contrast two-dimensional echocardiography: initial clinical observations.

Myocardial contrast two-dimensional echocardiography (MC-2DE) is a new technique to study myocardial perfusion imaging. Whether quantitative analysis of MC-2DE has any clinical significance is not known. We studied 12 patients during cardiac catheterization and coronary arteriography by MC-2DE, using sonicated iopamidol (microbubble size 12 +/- 4 micron) as the echocontrast agent. Selective intracoronary injections of 4 cc were performed into the left and right coronary artery. Two-dimensional echocardiograms were made before, during, and after injection from the apical four-chamber view. The coronary artery stenosis was calculated by automated boundary detection from the digitized cine arteriograms and expressed as percentage area stenosis (%S); also the absolute minimal luminal area (L) was calculated. From the MC-2DE video images, end-diastolic frames were chosen for digitization and videointensity measured from a region of interest at basal or midseptal level. This analysis reveals a curve of echo intensity versus time. From these curves, total curve area (A), curve duration (T), and time from peak intensity to 50% intensity decay (T50) were measured. Multiple regression analysis reveals the best correlation between %S and A (A = 52.48. e0.02%S; P less than .0001; r = 0.89). Correlations between %S, L, and T and T50, respectively, were less. Thus MC-2DE quantitative analysis shows a good agreement with anatomical size of coronary artery stenosis. These findings might have important clinical implications for future follow-up of various therapeutic procedures such as transluminal angioplasty thrombolysis.