Search PubMed⌕ Search

Biomedical subjects

D S Berman

Publications and source records attributed to D S Berman.

At least 55 records · Page 3Linked to original sources
PubMed1998

Comparative prognostic value of automatic quantitative analysis versus semiquantitative visual analysis of exercise myocardial perfusion single-photon emission computed tomography.

OBJECTIVES: The purpose of this study was to determine the prognostic value of automatic quantitative analysis in exercise dual-isotope myocardial perfusion single-photon emission computed tomography (SPECT) and to compare the prognostic value of quantitative analysis to semiquantitative visual SPECT analysis. BACKGROUND: Extent, severity and reversibility of exercise myocardial perfusion defects have been shown to correlate with prognosis. However, most studies examining the prognostic value of SPECT in chronic coronary artery disease (CAD) have been based on visual analysis by experts. METHODS: We studied 1,043 consecutive patients with known or suspected CAD who underwent rest Tl-201/exercise Tc-99m sestamibi dual-isotope myocardial perfusion SPECT and were followed up for at least 1 year (mean 20.0+/-3.7 months). After censoring 59 patients with early coronary artery bypass grafting or percutaneous transluminal coronary angioplasty, <60 days after nuclear testing, the final population consisted of 984 patients (36% women, mean age 63+/-12 years). RESULTS: During the follow-up period, 28 hard events (14 cardiac deaths, 14 nonfatal myocardial infarctions) occurred. Patients with higher defect extent (>10%), severity (>150) and reversibility (>5%) by quantitative SPECT defect analysis, as well as those with an abnormal scan (>2 abnormal segments, summed stress score >4 and summed difference score >2) by semiquantitative visual SPECT analysis, had a significantly higher hard event rate compared to patients with a normal scan (p < 0.001). With both visual and quantitative analyses, hard event rates of approximately 1% with normal scans and 5% with abnormal scans (p > 0.05) were observed over the 20-month follow-up period. A Cox proportional hazards regression model showed that chi-square increased similarly with the addition of quantitative defect extent and visual summed stress score variables after considering both clinical and exercise variables (improvement chi-square = 11 for both, p < 0.0007). There were no significant differences in the areas under receiver operating characteristic curves between quantitative and visual analysis (p > 0.70). Linear regression analysis also indicated that quantitative assessments correlated well with visual semiquantitative assessments. CONCLUSIONS: The findings of this study indicate that automatic quantitative analysis of exercise stress myocardial perfusion SPECT is similar to semiquantitative expert visual analysis for prognostic stratification. These findings may be of particular clinical importance in laboratories with less experienced visual interpreters.

Aged↗
PubMed1997

Automatic quantitation of regional myocardial wall motion and thickening from gated technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography.

OBJECTIVES: We developed an automatic quantitative algorithm for the measurement of regional myocardial wall motion and wall thickening from three-dimensional gated technetium-99m sestamibi myocardial perfusion single-photon emission computed tomographic images. BACKGROUND: The algorithm measures the motion of the three-dimensional endocardial surface using a modification of the centerline method, as well as wall thickening using both geometry (gaussian fit) and partial volume (counts). METHODS: The algorithm was tested using a "variable thickness" heart phantom, and the quantitative results were compared with visual segmental assessment of myocardial motion and thickening in 79 clinical patients with a wide range of ejection fractions (6% to 87%). RESULTS: Phantom measurements of simulated motion and thickening were accurate regardless of the camera used (dual or triple detector), the angular span of reconstructed data (180 degrees or 360 degrees), the amount of motion (3 or 6 mm) or the amount of thickening (33%, 50% or 100%). Quantitative measurements of segmental motion and thickening in the patients were correlated with visual scores (r = 0.668, exact agreement 72.6%, kappa 0.433 and r = 0.550, exact agreement 74.7%, kappa 0.408, respectively). Significant inverse linear relations exist between the global (summed) visual motion score and the average quantitative motion, and between the global (summed) visual thickening score and the average quantitative thickening. Automatic quantitative ejection fraction measurements correlated extremely well with average quantitative motion (r = 0.929) and thickening (r = 0.959). CONCLUSIONS: Our algorithm is accurate and may be the first automatic technique for the quantitative three-dimensional assessment of regional ventricular function in cardiology.

Aged↗
PubMed1997

Incremental prognostic value of adenosine stress myocardial perfusion single-photon emission computed tomography and impact on subsequent management in patients with or suspected of having myocardial ischemia.

We examined 1,159 consecutive patients who underwent adenosine stress dual isotope single-photon emission computed tomography (SPECT) and had follow-up performed at a mean of 27.5 +/- 9.1 months (94% complete) for hard events (cardiac death and myocardial infarction) and referral to cardiac catheterization after nuclear testing. During follow-up, 120 hard events occurred (11.0% hard event rate; 72 cardiac deaths [6.7% cardiac death rate] and 57 myocardial infarctions [5.3% myocardial infarction rate]). Cox proportional hazards analysis revealed that nuclear testing added incremental value after adjusting for clinical and historical variables (global chi-square increased 13 to 98 for cardiac death as the end point, global chi-square increased 19 to 105 for hard events as the end point; p <0.0001 for both). Kaplan-Meier analysis demonstrated that after clinical risk stratification of the patient population, the results of nuclear testing were further able to significantly stratify both low- and intermediate- to high-risk patients. Patients with both normal and mildly abnormal scans were at low risk of cardiac death (<1% cardiac death per year of follow-up) and the risk of events increased significantly with worsening scan result. Multivariable analysis revealed that the only predictor of referral to catheterization was the extent and severity of reversible defect present on the scan. Referral rates to early catheterization were very low in patients with normal scans and increased significantly as a function of worsening scan results. In patients who underwent myocardial perfusion SPECT using adenosine stress, the results of nuclear testing yielded incremental prognostic information and clinically relevant risk stratification. Referring physicians predominantly utilized nuclear information when referring patients to catheterization after nuclear testing and do so at rates comparable with those after exercise SPECT despite the higher risk of events in patients undergoing pharmacologic stress.

Adenosine↗
PubMed1997

Identification of severe or extensive coronary artery disease in women by adenosine technetium-99m sestamibi SPECT.

To assess the ability of adenosine technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography (SPECT) to identify high-risk women with severe or extensive coronary artery disease (CAD), we studied 130 consecutive women who underwent adenosine sestamibi myocardial perfusion SPECT and catheterization within 2 months. Severe (> or = 50% stenosis of left main coronary artery, > or = 90% stenosis in the proximal left anterior descending or in > or = 2 coronary arteries) or extensive (> or = 70% stenosis in 3 vessels) CAD was present in 54 patients, whereas 76 had no CAD or mild to moderate CAD. Semiquantitative visual SPECT analysis used 20 segments and a 5-point scoring system (0 = normal, 4 = absent uptake). Among the clinical, hemodynamic and nuclear variables analyzed, univariate predictors of severe or extensive CAD included a higher prescan likelihood of CAD, history of myocardial infarction, a higher heart rate at rest, a lower increase in heart rate during adenosine infusion, a higher summed stress score, summed reversibility score, and multivessel scan abnormality. Multivariate logistic analysis of the most predictive clinical (prescan likelihood of CAD), hemodynamic (increase in heart rate during adenosine infusion), and scan variables (summed stress score) revealed summed stress score (chi-square = 32; p <0.0001) and prescan likelihood of CAD (chi-square = 6.4; p <0.05) as the only independent predictors of severe or extensive CAD. Based on these logistic models, we determined the probability for the presence of severe or extensive CAD in patients with low, intermediate, and high prescan likelihood of CAD across the range of values of a summed stress score. This revealed that there were incremental increases in the probability for severe or extensive CAD both as a function of prescan likelihood of CAD and summed stress score. A severely abnormal scan (summed stress score > 8) during adenosine technetium-99m sestamibi myocardial perfusion SPECT had a high sensitivity of 91% and a moderately high specificity of 70% for identifying high-risk women with severe or extensive CAD. These results coupled with the previously defined prognostic significance of these findings suggest this test to be a useful diagnostic tool for the evaluation of CAD in women.

Adenosine↗
PubMed1997

Achieving sustained improvement in myocardial perfusion: role of isosorbide mononitrate.

The efficacy of antianginal agents in the treatment of patients with chronic stable angina has traditionally been evaluated by performance measures, such as the exercise treadmill test (ETT). Although reliable and reproducible, ETT is not a sensitive measure of changes in myocardial ischemia. The effects of antianginal agents on coronary blood flow and myocardial perfusion have been less frequently studied. Angiographic studies have demonstrated that nitrates may operate by preferentially directing blood flow to ischemic regions of the myocardium. These investigations have been limited, however, by the invasive nature of the evaluation. Measurements of regional myocardial perfusion may also be made with noninvasive tests. Both quantitative single-photon emission computed tomography (SPECT) and positron emission tomography (PET) have been employed, but few studies have used these techniques to assess the effects of antianginal drugs (in general) and nitrates (in particular) on changes in reversible myocardial perfusion defects. Studies that have evaluated the direct effects of nitrate treatment on coronary blood flow and myocardial perfusion defects in patients with chronic stable angina are reviewed, and preliminary data from a study of the effects of long-term nitrate treatment on myocardial perfusion are discussed.

Angina Pectoris↗
PubMed1997

Usefulness of hemodynamic changes during adenosine infusion in predicting the diagnostic accuracy of adenosine technetium-99m sestamibi single-photon emission computed tomography (SPECT).

Whether adenosine myocardial perfusion single-photon emission computed tomography (SPECT) remains accurate for detecting coronary artery disease (CAD) in the absence of peripheral hemodynamic changes is unknown. To assess the hemodynamic correlates of perfusion defects, we studied 222 consecutive patients (age 71 +/- 11 years) without prior myocardial infarction or revascularization who underwent adenosine technetium (Tc)-99m sestamibi myocardial perfusion SPECT and cardiac catheterization within 6 months of adenosine study. The SPECT protocol used separate acquisition of rest thallium-201 and adenosine Tc-99m sestamibi, which was semiquantitatively analyzed in 20 segments with a visual 5-point scoring system (0 = normal, 4 = absent uptake). The overall sensitivity, specificity, and predictive accuracy of adenosine Tc-99m sestamibi SPECT for detecting significant CAD were 93% (159 of 171), 73% (37 of 51), and 88% (196 of 222), respectively. The study population was grouped into 6 categories as a function of peripheral hemodynamic changes: (1) increase in heart rate by < or = 10 beats/min (n = 135); (2) increase in heart rate by > 10 beats/min (n = 87); (3) decrease in systolic blood pressure by < or = 10 mm Hg (n = 108); (4) decrease in systolic blood pressure by > 10 mm Hg (n = 114); (5) increase in heart rate by < or = 10 beats/min and decrease in systolic blood pressure by < or = 10 mm Hg (n = 72); and (6) increase in heart rate by > 10 beats/min or decrease in systolic blood pressure by > 10 mm Hg (n = 150). The sensitivity, specificity, and predictive accuracy of adenosine sestamibi SPECT were similar in all 6 categories. The prevalence of left main or multivessel CAD and extent of scan abnormality were also similar among all groups. Thus, the diagnostic accuracy of adenosine Tc-99m sestamibi SPECT is high in patients with or without peripheral hemodynamic evidence of adenosine effect.

Adenosine↗
PubMed1997

Imaging techniques for coronary artery disease: current status and future directions.

We review the current status and future directions of sestamibi single-photon emission-computed tomography (SPECT), position emission tomography (PET), magnetic resonance imaging (MRI), and contrast perfusion echocardiography (CPE) for coronary artery disease evaluation. Diagnostic accuracy and adjunctive assessment of ventricular function make sestamibi SPECT the currently favored stress imaging radioisotope technique. Tissue attenuation correction will likely enhance these capabilities of SPECT in the near future. PET potentially offers valuable diagnostic information, as it may be a superior technique where body habitus limits cardiac imaging. We project that it is unlikely to become routinely used for cardiac imaging because of improvements in routine radionuclide imaging and the lack of evidence that the small resolution gain with PET is of importance, given the much larger cost. Cardiac MRI for assessing cardiac function, perfusion, and coronary angiography is an exciting new modality at an early stage of development. The possible comprehensive nature of MRI for coronary artery disease evaluation, potential cost savings related to utilization of a single, noninvasive test, and availability of scanning equipment in current community settings all project an important role for MRI in the future. Contrast perfusion echocardiography is also a relatively new and untested imaging modality which offers great future promise. The recent development of intravenous contrast agents and the current widespread availability of echocardiographic expertise and equipment throughout the country suggest that the speed of development as well as the dispersion of technologic advances will be rapid. We project that these techniques will play important roles in future coronary artery disease testing and will result in improved diagnostic efficacy and possibly cost utility.

Coronary Disease↗
PubMed1997

The differing prognostic utility of exercise radionuclide ventriculography in coronary artery disease patients with and without prior myocardial infarction.

UNLABELLED: Previous studies have documented the prognostic utility of left ventricular ejection fraction response to exercise primarily in populations without prior myocardial infarction. We undertook a study to assess the prognostic utility of exercise left ventricular ejection fraction and segmental wall motion response during exercise radionuclide ventriculography in coronary artery disease patients with and without prior myocardial infarction. METHODS: We examined the comparative prognostic utility of left ventricular ejection fraction and segmental wall motion response during upright bicycle exercise radionuclide ventriculography in 419 coronary artery disease patients with (n = 217) and without (n = 202) prior myocardial infarction using univariate and multivariate hierarchical regression analyses. RESULTS: During an average followup period of 61 months, 96 patients (23%) suffered cardiac events, including 55/217 (25%) of the patients with prior myocardial infarction and 41/200 (21%) of the patients without prior myocardial infarction (p = ns). Both cumulative Kaplan-Meier survival analyses and stepwise hierarchical Cox survival analyses demonstrated that peak left ventricular ejection fraction < 55% was a significant predictor of cardiac events in patients without prior myocardial infarction (p = 0.04), whereas an exercise wall motion worsening score > or = 2 was a significant predictor in patients with a prior myocardial infarction (p = 0.0001). CONCLUSIONS: The prognostic utility of exercise radionuclide ventriculography variables differ according to the presence or absence of prior myocardial infarction. Global function, assessed by peak left ventricular ejection fraction, adds the greatest prognostic information in patients without prior myocardial infarction, whereas regional function, assessed by exercise wall motion worsening, is the best predictor among patients with prior myocardial infarction.

Adult↗
PubMed1997

An automatic approach to the analysis, quantitation and review of perfusion and function from myocardial perfusion SPECT images.

UNLABELLED: We have developed a software suite that automatically selects, analyses, quantitates and displays all the key image data in a myocardial perfusion SPECT study. METHODS: The files automatically selected (upon specification of the patient name) are rest and stress projections, rest and stress short axis and gated short axis files, and all 'snapshot' files. The projection data sets are presented in cine mode for evaluation of patient motion, while the lung/heart ratio at rest and stress is calculated from regions of interest (ROIs) that are automatically derived and overlayed on the LAO 45 images. Left ventricular (LV) cavity volumes at rest and stress are calculated from the short axis data sets, and the related transient ischemic dilation (TID) ratio derived and displayed. Quantitative measurements of global (ejection fraction) and regional function parameters are performed from the gated short axis dataset. All algorithms use the C++, X-Windows and OSF-Motif standards. The overall suite executes in less than 1 minute on a SunSPARC5 with 32 Mb of RAM and no proprietary hardware. RESULTS: The software was validated on 144 patients (118 rest 201T1/post-stress 99mTc-sestamibi, 18 post-stress 99mTC-sestamibi, 8 rest 201Tl) acquired on a 90 degrees dual detector (ADAC Vertex, 91 patients) and a triple detector camera (Picker Prism 3000, 53 patients). Overall, the individual algorithms for the analysis of projection, short axis and gated short axis images were successful in 622/660 (94.2%) of the images. In 80.5% of the patients (73/91 + 43/53) all algorithms executed successfully, without significant difference in success rates for 201Tl versus 99mTc-sestamibi images. CONCLUSION: Our automated approach to myocardial perfusion SPECT analysis and review is highly successful, intrinsically reproducible, and can produce time and cost savings while improving accuracy in a clinical or teleradiology-type environment.

Algorithms↗
PubMed1997

Cost implications of selective preoperative risk screening in the care of candidates for peripheral vascular operations.

The preoperative identification that patients are at high risk for adverse postoperative outcomes is the first step toward preventing costly in-hospital complications. The economic implications of noninvasive screening strategies in the care of patients undergoing peripheral vascular operations must be clarified. A decision model was developed from the peer-reviewed literature on patients undergoing preoperative screening by means of dipyridamole myocardial perfusion imaging, dobutamine echocardiography, or cardiac catheterization before vascular operations (n = 23 studies). Routine versus selective screening strategies were compared for patients with an intermediate likelihood of having coronary artery disease on the basis of clinical history of coronary disease or typical symptoms. Median costs (1994 US dollars) of preoperative screening strategies were derived with two microcosting approaches: adjusted Medicare charges (top-down approach) and a bottom-up approach with Duke University Center direct cost estimate data. In-hospital cost was 11% higher for preoperative screening by means of routine cardiac catheterization ($27,760) than for routine pharmacologic stress imaging ($24,826, P = 0.001). The total cost of a do-nothing strategy, that is, no preoperative testing, was 5.9% less than that of routine preoperative pharmacologic stress imaging and 15.9% lower than that of cardiac catheterization (P = 0.001). Selective screening among patients with a history of coronary disease or typical angina resulted in further reduction of the cost of care to a level comparable with that of a do-nothing strategy (52.5% reduction in cost with pharmacologic stress imaging, P > 0.20). Use of noninvasive testing for preoperative risk stratification was cost effective for patients 60 to 80 years of age. Cost per life saved ranged from $33,338 to $21,790. However, coronary revascularization after an abnormal noninvasive test was cost effective only for patients older than 70 years. In this economic decision model, substantial cost savings were predicted when selective noninvasive stress imaging was added to preoperative screening for patients about to undergo vascular operations. With a selective screening approach, the economic impact of initial diagnostic testing may be minimized without compromising patient outcomes.

Decision Trees↗
PubMed1997

Quantitative LVEF and qualitative regional function from gated thallium-201 perfusion SPECT.

UNLABELLED: This study investigates the feasibility of routine clinical 201Tl gated perfusion SPECT (gated Tl), and compares quantitative left ventricular ejection fraction (LVEF) and visually-assessed regional wall motion and thickening to analogous values obtained from 99mTc-sestamibi gated perfusion SPECT (gated MIBI). METHODS: We studied 121 patients with a rest gated Tl (3-3.5 mCi, 35 sec/ projection/poststress gated MIBI (25-30 mCi, 25 sec/projection) separate dual-isotope protocol on a 90 degrees dual-detector camera. Automatic quantitation of LVEFs was accomplished using previously developed and validated software, while visual scoring of motion and thickening was performed using four-point scales. RESULTS: Average myocardial counts were lower in gated Tl images (306 +/- 81 counts/pixel) compared to gated MIBI images (789 +/- 237 counts/pixel). The quality of gated Tl images was ranked as excellent, good, fair and poor in 24.0%, 42.1%, 24.8% and 9.1%, respectively, of the patients, compared to 43.0%, 43.8%, 9.1% and 4.1%, respectively, for gated MIBI images. Quantitative-gated Tl and gated MIBI LVEFs correlated well (y = 0.11 + 1.05x, r = 0.918, SEE = 6.35). Possible poststress myocardial stunning may have caused gated Tl LVEFs to overestimate gated MIBI LVEFs by a larger (p = 0.03) amount in ischemic patients (n = 47, y = -0.69 + 1.09x, r = 0.914, s.e.e. = 6.44) compared to nonischemic patients (n = 64, y = -1.58 + 1.05x, r = 0.919, s.e.e. = 5.93), the residual difference in LVEFs for this latter group being likely due to different isotope resolution in conjunction with small left ventricles. Exact agreement between gated Tl and gated MIBI segmental myocardial function in 41 nonischemic patients was 92.2% (kappa = 0.619) and 95.4% (kappa = 0.586) for motion and thickening scores, respectively. CONCLUSION: Thallium-201 gated SPECT imaging can be effectively performed on the majority of patients in our clinical environment and offers the opportunity to assess both myocardial perfusion and function using one injection and one imaging sequence, similarly to what is done with 99mTc-based agents.

Aged↗
PubMed1997

Clinical validation of automatic quantitative defect size in rest technetium-99m-sestamibi myocardial perfusion SPECT.

UNLABELLED: We examined the relationships of automatic quantitative perfusion defect size and defect severity to rest left ventricular ejection fraction and semiquantitative visual sestamibi defect size in rest 99mTc-sestamibi SPECT in 40 consecutive patients with a history of myocardial infarction more than 30 days prior to testing. The purpose of this investigation was to validate the use of automatic quantitative rest sestamibi SPECT as a clinical measure of assessing relative infarction size. METHODS: All patients received 20-30 mCi of 99mTc-sestamibi followed by SPECT imaging. Quantitative defect analysis used previously developed resting normal limits and an automatic version of a commercially available quantitative program (CEqual). Semiquantitative visual defect interpretation used a 20 segment/scan and five-point scoring analysis. First-pass (FP) radionuclide ventriculography (RVG) and gated sestamibi perfusion SPECT were each performed in 31 patients. RESULTS: LVEF assessed by FP RVG was 37% +/- 15% (range 14%-62%) and 37% +/- 16% (range 12%-63%) by gated perfusion SPECT with high linear correlation (r = 0.96, n = 22) between the two methods. Myocardial perfusion defect size was 24% +/- 15% of LV (range 0%-50%) and defect severity was 1103 +/- 864 (range 0 to 2825) by automatic quantitative rest sestamibi. Perfusion defect size and defect severity both had close correlations with LVEF by FP RVG (r = -0.78, r = -0.86) and by gated perfusion SPECT (r = -0.75, r = -0.79). High linear correlations were observed between quantitative defect size and summed visual score of segments with score > or = 2 (r = 0.82) and the number of visually abnormal segments (r = 0.77), as well as between defect severity and visual summed rest score (r = 0.86) and the number of visually abnormal segments (r = 0.76). CONCLUSION: Quantitation of rest sestamibi SPECT defect extent and severity using automatic CEqual correlates well with rest LVEF and with semiquantitative expert visual analysis. Results of this study define a strong relationship between measurements of 99mTc-sestamibi perfusion defect as measured by an automatic software program and global left ventricular function. The automatic quantitative program appears to be a useful measure of assessing infarct size in patients with remote myocardial infarction.

Adult↗
PubMed1996

Adenosine technetium-99m sestamibi myocardial perfusion SPECT in women: diagnostic efficacy in detection of coronary artery disease.

OBJECTIVES: This study sought to assess the diagnostic efficacy of adenosine technetium-99m sestamibi myocardial perfusion single-photon emission computed tomography (SPECT) in a consecutive series of female patients. BACKGROUND: The utility of adenosine myocardial perfusion SPECT for the detection of coronary artery disease is not well defined in women because most studies have described a predominantly male population with a high prevalence of coronary artery disease. METHODS: Of the 201 consecutive female patients in the study group who had undergone adenosine Tc-99m sestamibi myocardial perfusion SPECT, 130 had coronary angiography within 2 months of the nuclear test, and the other 71 had a low likelihood (<10%, mean [+/-SD] 5 +/- 3%) of coronary artery disease. The SPECT protocol used separate acquisition of rest thallium-201 and adenosine Tc-99m sestamibi and was visually analyzed in 20 segments with a semiquantitative five-point scoring system (0=normal; 4=absent uptake). RESULTS: The normalcy rate in patients with a low likelihood of coronary artery disease was 93% (66 of 71). Among the catheterized group, the overall sensitivity, specificity and predictive accuracy of adenosine sestamibi SPECT for detecting coronary artery disease (> or = to 50% diameter stenosis) were 93% (87 of 94), 78% (28 of 36) and 88% (115 of 130), respectively. In the 103 patients without a prior myocardial infarction, the sensitivity, specificity and predictive accuracy were 91% (61 of 67), 78% (28 of 36) and 86% (89 of 103), respectively, for detecting > or = to 50% diameter stenosis. Of particular interest, the sensitivity and specificity were as high in patients with nonanginal symptoms (93% and 69%, respectively) as in patients with angina (92% and 83%, respectively, p=NS). The sensitivity and specificity among patients with a relatively low (<25%), intermediate (between 25% and 75%) or high prescan likelihood of coronary artery disease (>75%) were similar: 82% and 82%, 93% and 73%, and 95% and 100%, respectively. The sensitivity and specificity for detecting individual diseased vessels (> or = to 50% diameter stenosis) were, respectively, 76% and 81% for the left anterior descending coronary artery, 44% and 90% for the left circumflex coronary artery and 75% and 77% for the right coronary artery. CONCLUSIONS: Adenosine Tc-99m sestamibi SPECT is an efficient protocol with high sensitivity and specificity for the detection of coronary artery disease in women irrespective of presenting symptoms or pretest likelihood of coronary artery disease and a high normalcy rate. These findings are of particular clinical relevance because chest pain, anginal or otherwise, has been shown to be a frequent but a less specific marker for coronary artery disease among female patients.

Adenosine↗
PubMed1996

Exercise myocardial perfusion SPECT in patients without known coronary artery disease: incremental prognostic value and use in risk stratification.

BACKGROUND: We evaluated the incremental prognostic value, the role in risk stratification, and the impact on patient management of myocardial perfusion single-photon emission computed tomography (SPECT) in a population of patients without prior myocardial infarction, catheterization, or revascularization. METHODS AND RESULTS: We examined 2200 consecutive patients who at the time of their dual-isotope SPECT had not undergone catheterization, coronary artery bypass surgery, or percutaneous transluminal coronary angioplasty and had no known history of previous myocardial infarction. Follow-up was performed at a mean of 566 +/- 142 days (97% complete) for hard events (cardiac death and myocardial infarction) and for referral to cardiac catheterization or revascularization within 60 days after nuclear testing. Examination of clinical, exercise, and nuclear models by use of pre-exercise tolerance test (ETT), post-ETT, and nuclear information using a stepwise Cox proportional hazards model and receiver-operating characteristic curve analysis revealed that nuclear testing added incremental prognostic value after inclusion of the most predictive clinical and exercise variables (global chi2 = 12 for clinical variables; 31 for clinical + exercise variables; 169 for nuclear variables; gain in chi2, P < .0001 for all; receiver-operating characteristic areas: 0.66 +/- 0.04 for clinical, 0.73 +/- 0.04 for clinical + exercise variables, 0.87 +/- 0.03 for nuclear variables, P = .03 for gain in area with exercise variables; P < .001 for increase with nuclear variables). Multiple logistic regression analysis revealed that scan information contributed 95% of the information regarding referral to catheterization with further additional information provided by presenting symptoms and exercise-induced ischemia. Referral rates to early catheterization and revascularization paralleled the hard event rates in all scan categories - very low referral rates in patients with normal scans and significant increases in referral rates as a function of worsening scan results. Even after stratification by clinical and exercise variables such as the Duke treadmill score, pre- and post-ETT likelihood of coronary artery disease, presenting symptoms, sex, and age, the nuclear scan results further risk-stratified the patient subgroups, thus demonstrating clinical incremental value. CONCLUSIONS: In a patient population with no evidence of previous coronary artery disease at overall low risk (1.8% hard event rate), myocardial perfusion SPECT adds incremental prognostic information and risk-stratifies patients even after clinical and exercise information is known. It appears that referring physicians use this test in an appropriate manner in selecting patients to be referred to catheterization or revascularization.

Cardiac Catheterization↗
PubMed1996

Identification of severe and extensive coronary artery disease by automatic measurement of transient ischemic dilation of the left ventricle in dual-isotope myocardial perfusion SPECT.

OBJECTIVES: This study sought to assess whether a transient ischemic dilation ratio, determined from automatically derived stress and rest left ventricular volumes during stress technetium-99m (Tc-99m) sestamibi/rest thallium-201 dual-isotope myocardial perfusion single-photon emission computed tomography (SPECT), is useful for the identification of patients with severe and extensive coronary artery disease. BACKGROUND: Transient ischemic dilation of the left ventricle on stress/redistribution thallium-201 scintigraphy has been shown to be a clinically useful marker of severe and extensive coronary artery disease. However, in practice, its assessment is highly subjective. This study automatically assessed the transient ischemic dilation ratio on the basis of a previously described algorithm to estimate three-dimensional ventricular boundaries. METHODS: Normal limits for the transient ischemic dilation ratio were developed using data from 54 patients with a low likelihood (< 5%) of coronary artery disease, and criteria for abnormality were developed based on data from 97 who under-went catheterization, of whom 34 had severe and extensive coronary artery disease, defined as > or = 90% stenosis in the proximal left anterior descending coronary artery or in two or more coronary arteries, and 63 had no coronary artery disease (15 patients) or mild to moderate coronary artery disease (48 patients). The criteria were then tested in a validation cohort of 77 additional patients who underwent catheterization, of whom 36 had severe and extensive coronary artery disease. The quantitative results of the dilation ratio were compared with the visual results of the dilation ratio and perfusion defect analysis. RESULTS: For normal limits, receiver operating characteristic curve analysis showed that abnormal transient ischemic dilation ratio values corresponded to left ventricular endocardial volume ratios > 1.22 (mean +/- 2 SD). Transient ischemic dilation assessment using these criteria for abnormality showed high sensitivity (24 [71%] of 34) and very high specificity (60 [95%] of 63) for severe and extensive coronary artery disease. When the analysis was applied to the prospective catheterization group, similar sensitivity and specificity for severe and extensive coronary artery disease were observed (77% and 92%, respectively). Significant agreement (p = 0.0001) was found between the degree of transient ischemic dilation and the Tc-99m sestamibi defect extent, the latter assessed by semiquantitative visual analysis (summed stress score). CONCLUSIONS: The automatic measurement of transient ischemic dilation in dual-isotope myocardial perfusion SPECT is a clinically useful marker that is sensitive and highly specific for detection of severe and extensive coronary artery disease.

Aged↗
PubMed1996

Effective risk stratification using exercise myocardial perfusion SPECT in women: gender-related differences in prognostic nuclear testing.

OBJECTIVES: This study was designed to evaluate the incremental prognostic value over clinical and exercise variables of rest thallium-201/exercise technetium-99m sestamibi single-photon emission computed tomography (SPECT) in women compared with men and to determine whether this test can be used to effectively risk stratify patients of both genders. BACKGROUND: To minimize the previously described gender-related bias in the evaluation of coronary artery disease in women, there is a need to identify a noninvasive testing strategy that is able to accurately and effectively risk stratify women. METHODS: We identified 4,136 consecutive patients (2,742 men, 1,394 women) who underwent dual-isotope SPECT. The incremental value of nuclear testing was determined using both a stepwise Cox proportional hazards model and Kaplan-Meier survival analysis. Receiver operating characteristic curve analysis was performed to determine test discrimination for high risk patients in men and women. RESULTS: The patient population was followed up for 20 +/- 5 months for events (cardiac death or nonfatal myocardial infarction). During this time, 63 myocardial infarctions and 32 cardiac deaths occurred in the men, and 31 myocardial infarctions and 14 cardiac deaths occurred in the women. Nuclear testing significantly stratified both men and women irrespective of their rest electrocardiogram. Cox proportional hazards analysis revealed that nuclear testing added incremental prognostic value in both men and women after inclusion of the most predictive clinical exercise variables (overall chi-square 89 in men vs. 120 in women, p < 0.005). Kaplan-Meier survival analysis demonstrated that nuclear testing further stratified men and women with both intermediate to high and low prescan likelihoods of coronary artery disease (p < 0.005 for all). Receiver operating characteristic curve analysis demonstrated superior discrimination for the nuclear scan results in identifying high risk women than men (area under the curve: 0.84 +/- 0.03 vs 0.71 +/- 0.03 in men, p < 0005). The odds ratio comparing event rates in patients with women than in men, suggesting superior stratification using nuclear testing in women. CONCLUSIONS: Dual-isotope myocardial perfusion imaging yields incremental prognostic value in both men and women. This modality identifies low risk women and men equally well but relatively high risk women more accurately than relatively high risk men and, thus, is able to stratify women more effectively than men.

Bias↗
PubMed1996

Impact of myocardial perfusion single-photon emission computed tomography on referral to catheterization of the very elderly. Is there evidence of gender-related referral bias?

OBJECTIVES: This study sought to assess the impact of myocardial perfusion studies on subsequent management in the very elderly with respect to referral to catheterization or revascularization. BACKGROUND: The very elderly are a rapidly growing segment of the U.S. population, and myocardial perfusion studies are frequently performed in this patient subset for evaluation of coronary artery disease. METHODS: The study utilized 1,006 consecutive patients > or = 80 years old (511 men, 495 women) who underwent stress myocardial perfusion single-photon emission computed tomography (SPECT) using pharmacologic stress (n = 605) or treadmill exercise (n = 401). Referral to catheterization or revascularization within 60 days of the nuclear scan was correlated with clinical and nuclear variables. RESULTS: Catheterization and revascularization were performed in 119 and 77 patients, respectively. Stratification of referral rates showed a low rate in normal and mildly abnormal scan categories and significantly higher rates in patients with severely abnormal scan results irrespective of the presenting symptoms or pretest likelihood of coronary artery disease. Multiple logistic regression analysis of clinical and nuclear variables revealed that extent and severity of reversibility by SPECT and the final scan result were the two most powerful predictors of referral to catheterization and revascularization in men and women (catheterization: chi-square 65 and 78; revascularization: chi-square 37 and 68, respectively). Overall, referral rates to catheterization and revascularization were similar in men and women (catheterization: 13% vs. 11%; revascularization: 8% vs. 8%, respectively). However, women with severely abnormal scan results were more frequently referred to catheterization (28% vs. 18%, p < 0.03) and revascularization (21% vs. 12%, p < 0.01) than men. CONCLUSIONS: In patients > or = 80 years old, myocardial perfusion SPECT had a significant impact on patient management. The apparent discrepancy in referral rates for interventional management in men and women is unexplained but may be appropriate in light of our previous observations that women with severely abnormal scan results are at increased risk for hard cardiac events than are men with severely abnormal scan results.

Age Factors↗