Dobutamine stress myocardial perfusion imaging

Liver transplantation: Do you have the heart for it?

Incremental value of combining 64-slice computed tomography angiography with stress nuclear myocardial perfusion imaging to improve noninvasive detection of coronary artery disease

Improved Accuracy of the Exercise Electrocardiogram in Detection of Coronary Artery and Three-Vessel Coronary Disease

We sought to investigate the utility of stress single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) for the identification of coronary artery disease (CAD) in the distribution of first-order branch vessels. We evaluated 135 consecutive patients with coronary angiography and stress SPECT MPI. We anatomically matched angiography and SPECT to assess the sensitivity, specificity and accuracy of SPECT MPI for the detection of CAD in the distribution of first-order branches. Subgroup analysis for stress test performance and previous coronary artery bypass grafting (CABG) was also performed. The sensitivity, specificity and accuracy of stress SPECT MPI for the detection of CAD in the distribution of first-order branch vessels were all 67%. For isolated branch vessel CAD, stress SPECT MPI had a sensitivity of 44%. In patients without CABG, the sensitivity, specificity and accuracy for the detection of CAD in the distribution of first-order branch vessels were 71%, 67% and 68%, compared with 60%, 67% and 64% for patients with CABG. The sensitivity for isolated branch vessel CAD was 50% for patients without CABG, but only 29% for patients with CABG. The sensitivity and specificity for CAD in the distribution of branch vessels were similar for all patients for all stress test modalities and heart rate response (sensitivity, 64-69%; specificity, 61-69%). Stress SPECT MPI offers intermediate sensitivity, specificity and accuracy for the detection of CAD in the distribution of first-order coronary artery branch vessels. However, for isolated branch vessel CAD, stress SPECT has a lower sensitivity, particularly in patients with previous CABG.

This study was done to evaluate the quantification of thallium-201 myocardial perfusion imaging (MPI) for the detection of coronary artery disease (CAD). Segmental analysis of stress and delayed MPI was performed in 33 patients with angiographically proved CAD. They were divided into two groups : 22 patients without previous infarction (Group 1) and 11 patients with prior myocardial infarction (Group 2). Using computer analysis of MPI, 9 region-of-interests (ROIs) were set on the left ventricular image. We defined 3 indices as follows : initial uptake (%) = a ratio of ROI counts to the highest ROI counts on the exercise image ; washout rate (WR) = a ratio of [(ROI counts of the exercise image) - (those on the delayed image)] to those on the exercise image : redistribution index (ROI)= a ratio of the maximal WR to WR. Coronary arteriograms were evaluated according to Pujadas' method. In group 1, the region supplied by the coronary artery with significant stenosis showed a lower initial uptake (p < 0.005) and a higher ROI (p < 0.001) than the region supplied by the coronary artery without significant stenosis. If an initial uptake less than 83% and/or a RDI greater than 1.15 are defined as abnormal, the sensitivity for detecting CAD, including the detection of a stenosis site, was 76% and the specificity was 84%. In group 2, the sensitivity was 76% and the specificity was 80%. The mean WR could also indicate the severity of CAD. In all patients studied., the average of mean WR was 0.451 in one-vessel disease (n=18), 0.446 in two-vessel disease (n=6) and 0.305 in three-vessel disease (n=8). In conclusion, the quantitative evaluation of stress MPI using initial uptake, RDI and WR appear to be useful for noninvasive and objective diagnosis of CAD, particularly in detecting the severity and location of stenotic coronary arteries.

*Corresponding author: Ali Hosseinsabet, Cardiology Department, Tehran Heart Center, North Karegar Street, Tehran, IR Iran, Tel/Fax: +98-2188029731, E-mail: ali_hosseinsabet@yahoo.com Dear Editor, Dobutamine stress echocardiography is one of the several noninvasive methods for detection of coronary artery disease (1). New regional wall motion abnormalities have been reported in dobutamine stress echocardiograpghy after intravenous beta blocker administration (2, 3) Thus, this method has been recommended for increasing the test sensitivity (4). The sensitivity, specificity, accuracy, and positive and negative predictive values of dobutamin stress echocardiography without beta blocker have been reported to be 84%, 92%, 87%, 95%, and 77%, respectively. Using beta blocker, on the other hand, these measures have been reported as 92%, 89%, 91%, 94%, and 87%, respectively (3). In theory, beta blocker induced false positive dobutamine stress echocardiography can occur (5). In this study, a 49 year old woman with the history of abnormal uterine bleeding was candidate for abdominal hysterectomy. The patient complained about atypical chest pain without any defined coronary artery disease risk factors, and was referred for dobutamine stress echocardiography evaluation for preoperative risk stratification. In physical examinations, the patient’s heart and lung had unremarkable findings and other cardiovascular examinations were normal. The vital signs before dobutamine stress echocardiography were heart rate = 88 bpm, blood pressure = 135 / 80 mmHg, and respiratory rate = 15. Besides, electrocardiography showed normal sinus rhythm with no ST-T changes. Additionally, resting echocardiography showed normal Left Ventricular Ejection Fraction (LVEF) (LVEF = 55%) with no regional wall motion abnormalities, mild LV diastolic dysfunction, and no significant valvular diseases. Dobutamine doses were increased step by step to 40 mic / Kg / min and the heart rate increased to 145 bpm (90% maximal predicted heart rate), blood pressure increased to 140 / 80 mmHg with no regional wall motion abnormalities, and LVEF increased to 65%. Then, Esmolol 0.5 mg / Kg was administrated in one minute (6). Thereafter, the heart rate decreased to 77 bpm, blood pressure decreased to 130 / 80 mmHg, inferior and inferoseptal walls appeared to be hypokinetic, and LVEF decreased to 45 50%. It should be mentioned that the patient was asymptomatic during the procedure without any ST segment changes. According to dobutamine stress echocardiography results, the patient was referred for selective coronary angiography.

This study was performed to evaluate whether left ventricular hypertrophy (LVH) can influence the diagnostic accuracy of coronary artery disease (CAD) using the dobutamine stress echocardiography (DSE) in hypertensive patients. In addition to the detection of CAD, the relationship between systolic dysfunction and the quantitation wall motion scoring system of DSE was studied also. DSE was performed in 101 patients. There were 45 (45%) patients with a history of acute myocardial infarction. Twenty-eight patients (28%) had electrocardiographic LVH and 59 patients (58%) had echocardiographic LVH. A total of 74 patients (73%) had angiographically documented CAD defined as > or = 50% diameter stenosis. For the 56 patients without history of myocardial infarction, the diagnostic sensitivity, specificity, and accuracy in detecting CAD were not influenced by LVH defined by either electrocardiography or echocardiography. For the total patients, the diagnostic sensitivity, specificity, and accuracy in detecting multivessel disease were also not influenced by LVH defined by either method. The resting global wall motion score was correlated well with the left ventricular ejection fraction in patients with and without LVH (r = -0.70, p < 0.001 vs. r = -0.70, p < 0.001). When using the resting wall motion score of 24 as a cutoff value, the diagnostic sensitivity, specificity, and accuracy of systolic dysfunction (defined by left ventricular ejection fraction <40%) were 79, 86 and 85%, respectively. In conclusion, the diagnostic accuracy of CAD using the DSE was not affected by LVH in hypertensive patients. In addition to detection of coronary artery disease, the resting wall motion score of DSE was able to detect systolic dysfunction in patients with and without LVH.

Transesophageal dobutamine stress echocardiography in the evaluation of coronary artery disease

PET/CT imaging of myocardial blood flow and arterial calcium: Putting the pieces together

Objectives: Dobutamine stress echocardiography (DSE) and contrast-enhanced electron beam tomography (EBCT) both have the potential to noninvasively detect coronary artery disease (CAD). We compared the accuracy of both methods to detect significant CAD in a direct comparison. Methods: 79 patients (32 women, 47 men, mean age 62 years) who were admitted for coronary angiography due to suspected CAD were studied. By EBCT coronary calcification (CAC) as well as angiography (CTA) was assessed. Presence of significant CAD was assumed if the calcium score exceeded 400 or the contrast-enhanced images displayed significant lumen reduction. DSE was performed using a standard protocol (5–40 µg/kg/min dobutamine plus 0.25–1.0 mg atropine if necessary). DSE and EBCT were independently evaluated concerning the presence of signficant CAD. Results were compared to invasive, quantitative coronary angiography. Results: 6 patients (8%) in DSE and 2 patients (3%) in EBCT were unevaluable for various reasons and therefore excluded from further analysis. In the remaining 71 patients, 33 patients (46%) showed significant CAD. DSE demonstrated a sensitivity of 70% (23/33) and a specificity of 84% (32/38). EBCT showed a sensitivity of 91% (30/33) and a specificity of 74% (28/38). By combining DSE and EBCT sensitivity increased to 97% with a specificity of 63%. Conclusions: In a blinded comparison, DSE demonstrated lower sensitivity but higher specificity than EBCT for the detection of significant CAD. Sensitivity was improved by combining both modalities.

BackgroundThe purpose of this study was to evaluate whether performing an assessment of myocardial deformation using speckle tracking imaging during the recovery period after dobutamine stress echocardiography (DSE) allows detection of significant coronary artery disease (CAD) in patients with chest discomfort.MethodsDSE and coronary angiography were performed in 44 patients with chest discomfort. The mean global longitudinal peak systolic strain (GLS) was measured at rest, at low stress (dobutamine infusion rate of 10 µg/kg/min) and at recovery (5 min after cessation of dobutamine infusion) of DSE using automated function imaging with apical views. Fractional flow reserve (FFR) was also performed in patients with intermediate coronary stenosis. CAD was defined as having a ≥ 70% diameter stenosis on coronary angiography or as having a FFR < 0.8. Patients were divided two groups based on the absence or presence of CAD [CAD (-) group vs. CAD (+) group].ResultsThere were no significant differences in the clinical characteristics and results of conventional echocardiography between the two groups. GLS at recovery was lower in the CAD (+) group than in the CAD (-) group (-18.0 ± 3.4% vs. -21.0 ± 1.9%, p = 0.003). The optimal cutoff of GLS at recovery for detection of CAD was -19% (sensitivity of 70.6%, specificity of 83.3%).ConclusionAssessment of GLS at recovery of DSE is a reliable and objective method for detection of CAD. This finding may suggest that systolic myocardial stunning remains even after recovery of wall motion abnormalities in patients with CAD.

Dobutamine stress echocardiography in the detection of coronary artery disease in a clinical practice setting

Dynamic 3-Dimensional Stress Cardiac Magnetic Resonance Perfusion Imaging: Detection of Coronary Artery Disease and Volumetry of Myocardial Hypoenhancement Before and After Coronary Stenting

The purpose of the present study was to evaluate the feasibility and diagnostic accuracy of same day short rest-dobutamine stress Tetrofosmin (TF) SPECT imaging protocol and to compare TF SPECT results with MIBI SPECT in the same subjects who were unable to perform treadmill exercise or were unsuitable for pharmacological vasodilator stress. The study group consisted of 19 patients (2 female and 17 male, with a mean age of 53.8 +/- 7.9 yrs) in whom coronary artery disease (CAD) had been proven or excluded at coronary angiography (CA). MIBI SPECT imaging was performed first. TF SPECT images were obtained one week after MIBI imaging. Immediately after the rest SPECT imaging in both of the MIBI and TF studies, patients underwent dobutamine stress tests. Rest-stress radiotracer doses and dobutamine doses were the same for both TF and MIBI studies. While 60 min waiting periods were applied for MIBI study, only 30 min waiting periods were applied for TF study after the rest and stress injections. Images were evaluated by visual and quantitative analysis. Dobutamine stress parameters were similar for both studies. Although in TF study, the time between radiopharmaceutical injection and imaging was shorter than in MIBI study, there was no significant difference between heart-to-liver (H/Li) and heart-to-lung (H/Lu) ratios. According to CA results, diagnostic accuracy was similar for TF and MIBI. While sensitivity, specificity and accuracy for TF study were calculated as 82%, 84% and 82%, respectively, the corresponding values for MIBI were 82%, 88% and 84%, respectively. This clinical study has shown comparable diagnostic performance for the detection of CAD between MIBI and TF. Good correlation was found between segmental analysis for both studies. MIBI and TF showed similar perfusion defects and good segmental correlation during dobutamine stress with the same quality images. Both radiopharmaceuticals may be acceptable with this imaging protocol. Besides this, TF study showed better reversibility degree (55%) in a shorter time when compared to MIBI study (25%) in perfusion defects (especially in segments with severely decreased perfusion or no uptake).

Determination of the quantitative thallium imaging variables that optimize detection of coronary artery disease