Both stress and rest imaging are usually performed to diagnose ischemia or infarction in the left ventricle. If the stress study is performed first and the images indicate normal findings, it might be unnecessary to perform the rest study. The current study determines whether nuclear medicine technologists can assess the necessity of a rest study. METHODS: The results of gated SPECT performed using a 2-d nongated stress and gated rest (99m)Tc-sestamibi protocol for 532 consecutive patients were studied. Myocardial perfusion imaging was performed for diagnosing coronary artery disease (CAD) in 421 patients and for managing known CAD in 107 patients; 4 patients were examined for other reasons. Seventy-nine patients had previous myocardial infarction. Visual interpretation by 1 experienced physician at the time of clinical reporting was used as the gold standard for determining the scintigraphic presence of myocardial infarction or ischemia; rest, stress, and gated rest images and clinical information were available to this physician. All cases categorized as infarction or ischemia present or probably present were categorized as the group requiring a rest study (i.e., the "rest-study-required group"), whereas all other cases were categorized as the group not requiring a rest study (i.e., the "no-rest-study-required group"). A total of 3 physicians and 3 technologists independently interpreted the nongated stress images (slice images and polar plots) and decided whether a rest study was required. RESULTS: In the rest-study-required group, the 3 technologists correctly classified on average 171 of the 172 cases, and the 3 physicians correctly classified 169 (a difference that was not statistically significant). In the no-rest-study-required group, the physicians correctly classified 32% and the technologists 21% of the cases (P = 0.001). The risk that a patient sent home without a rest study would have been diagnosed with infarction or ischemia using the combined stress-rest interpretation was 1.3% (1/75) for the technologists and 2.6% (3/115) for the physicians. CONCLUSION: The nuclear medicine technologists were able to assess whether a rest study was needed; the risk that this assessment would be incorrect was not higher for the technologists than it was for the physicians. This type of assessment by a nuclear medicine technologist could be of value in efforts to improve effectiveness at a nuclear medicine clinic.
OBJECTIVES We wanted to evaluate whether preoperative myocardial perfusion scintigraphy (MPS) could predict changes in cardiac symptoms and postoperative myocardial perfusion and left ventricular function after coronary artery bypass grafting (CABG). METHODS Ninety-two patients with stable angina pectoris (and at least one occluded coronary artery) underwent MPS before, and 6 months after, undergoing CABG. The result of the MPS was kept secret from the surgeons. RESULTS Before CABG, 90% of the patients had angina. After CABG, 97% of the patients were without symptoms. Overall graft patency was 84%. Before CABG, one patient had normal perfusion; in the rest of them the defects were classified as follows: reversible (60%), partly reversible (27%) and irreversible (12%). Following CABG, 33% had normal perfusion; in the rest the defects were reversible in 29%, partly reversible in 12% and irreversible in 26%. Left ventricular ejection fraction (LVEF), which was normal before operation in 45%, improved in 40% of all patients. The increase in LVEF was not related to the preoperative pattern of perfusion defects. Of 30 patients with normalized perfusion after CABG, 29 (97%) had reversible defects and one patient had partly reversible defects. Of 83 perfusion defects, which were normalized after CABG, 67 were reversible (81%) or partly reversible (12%). Seventy-five percent of all reversible coronary artery territories before CABG were normalized after operation. CONCLUSIONS Our results indicate that reversible or partly reversible perfusion defects at a preoperative MPS have a high chance of normalized myocardial perfusion assessed by MPS 6 months after operation. Normal perfusion is obtained almost exclusively in territories with reversible ischaemia. Symptoms improved in nearly all patients and LVEF in a significant fraction of the patients, not related to preoperative MPS.
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In patients with heart failure (HF) due to coronary disease, a combined evaluation of perfusion and glucose metabolism by cardiac single photon emission computed tomography (SPECT)/positron emission tomography (PET) can be used to distinguish viable from non-viable myocardium, and current guidelines recommend cardiac SPECT and fluorodeoxyglucose (FDG) PET for viability assessment. Takotsubo cardiomyopathy (TTC) is a disease characterized by acute but reversible HF leaving no scarring. To explore how robust the semi-quantitative viability criteria used in cardiac SPECT and FDG PET stands their ground in a population with TTC. From 1 September 2009 to 1 October 2012, 24 patients suspected of TTC were enrolled in a multimodality cardiac imaging research project. Echocardiography, (99m)Tc SPECT, and (18)F FDG PET were performed during the acute admission and at follow-up 4 months later. Nineteen patients had a final diagnosis of TTC consistent with Mayo Clinic Diagnostic Criteria. Three of these patients were excluded from further analysis, since wall motion abnormalities were not persistent at the time of nuclear imaging. The remaining sixteen patients exhibited a distinct pattern with HF, "apical ballooning" and a perfusion-metabolism defect in the midventricular/apical region. When viability criteria were applied, they identified significant scarring/limited hibernation in the akinetic part of the left ventricle. However, full recovery was found in all TTC patients on follow-up. Using the current guideline-endorsed viability criteria for semiquantitative cardiac SPECT and FDG PET, these modalities failed to demonstrate the presence of viability in the acute state of TTC.
OBJECTIVES. Changes in the electrical activity of the heart reflecting the infarct process can be recorded by continuous vector-ECG, a method which is now clinically available for cardiac supervision. Shifts of the ST-segment and QRS-vector reflect ischaemia and necrosis of the myocardium. Continuous vector-ECG changes were evaluated against myocardial scintigraphy in 18 patients with acute myocardial infarction treated with streptokinase in order to study the impact of improved myocardial perfusion. DESIGN. Myocardial perfusion was analysed with 99Tcm-Sestamibi (Cardiolite, DuPont Scandinavia AB, Kista, Sweden) single photon emission computerized tomography (SPECT). Registrations were performed before and after thrombolysis in order to estimate the amount of myocardium with impaired perfusion initially (threatened myocardium) and the degree of perfusion improvement in this myocardial area. X, Y, Z vectors were registered continuously by Frank leads (Ortivus Medical, Täby, Sweden). QRS-vector difference, and the time to plateau phase and the ST-vector magnitude were used as a measurement of ischaemia and size of the myocardial infarction. RESULTS. In seven out of 11 patients treated within 3 h of onset of symptoms, an improvement in myocardial perfusion in the initially hypoperfused areas was achieved in contrast to none of the seven patients treated > 3 h after onset of pain (P
BACKGROUND: Assessments of compromised myocardium and infarct size early after thrombolytic treatment in acute myocardial infarction (AMI) are important for risk stratification and for treatment management. We have therefore evaluated the clinical usefulness of myocardial perfusion scintigraphy (MIBI-SPECT) for the assessment of myocardial viability early after AMI. METHODS: Seventy-one patients [53 men and 18 women, aged 64 +/- 9 years (range 45-75 years)] with AMI treated by thrombolysis took part in this prospective study at University Hospital, Stockholm, Sweden. Sixty of them underwent adenosine-stress and resting MIBI-SPECT 2-4 days after AMI, and 11 were examined only at rest. Six months after the AMI, a repeat MIBI-SPECT at rest was obtained for comparison. RESULTS: All patients had significant perfusion defects compared with an age- and sex-matched healthy reference population. Seventy-six percent of the patients able to undergo a complete adenosine-stress and rest SPECT showed signs of reversible perfusion defects. Defect size (extent) and severity at rest decreased between the tests at 2-5 days and 6 months after AMI (P
Stress dipyridamole technetium-99(m) sestamibi single photon emission computed tomographic imaging was used to study myocardial perfusion in 1116 hypertensive patients without known coronary artery disease (CAD). The test confirmed the presence of CAD in 28.9% of patients. As expected, patients with diabetes mellitus (DM) had a significantly higher prevalence of myocardial perfusion abnormalities (35.9% vs 23.9%; odds ratio, 1.79; 95% confidence interval [CI], 1.38-2.33; P
This study presents the outcome of myocardial scintigraphy performed before and after thrombolytic treatment in 16 patients with acute myocardial infarction using 99Tcm-Sestamibi (Cardiolite, Du Pont Scandinavia AB, Kista, Sweden). The patients were given 99Tcm-Sestamibi intravenously as soon as possible after the decision to give thrombolytic treatment. When the patients were in a clinically stable state after the thrombolytic treatment, myocardial perfusion was analysed with the gamma camera using single photon emission computerized tomography (SPECT). A second 99Tcm-Sestamibi tomography was carried out on the second to fourth day after the myocardial infarction. Data reconstruction was done with the 'Bull's eye technique'. Nine patients received thrombolysis 10% after treatment, while all seven patients who received treatment > or = 3 h after the onset of pain improved their myocardial perfusion by
OBJECTIVE: To assess reproducibility and validity of clinical classification of angina pectoris (AP) patients. DESIGN: Fifty-six patients scheduled for coronary angiography because of stable AP were classified by two independent observers with regard to (i) type and (ii) severity of chest pain (Canadian Cardiovascular Society, CCS) and (iii) cardiac functional status (New York Heart Association, NYHA). Myocardial perfusion imaging (MPI) was performed in 55 including measurement of ejection fraction in 46, angiography was undertaken in 51. RESULTS: Observers agreed 100% on the presence (n = 45) or absence (n = 11) of angina. They agreed in 52 (93%), 48 (86%), and 42 (75%) patients with regard to type of pain, CCS grade, and NYHA class, respectively. In the remaining patients, they disagreed by one class only. The positive and negative predictive values of typical/atypical angina for perfusion abnormalities and coronary disease were 55%/82% and 53%/ 82%, respectively. CONCLUSIONS: Observer agreement was excellent for presence, type, and severity of chest pain but moderate with regard NYHA class. Clinical judgment could not predict with reasonable accuracy abnormal perfusion or coronary artery disease.
BACKGROUND: Observer variability of dual-isotope myocardial perfusion imaging (MPI) with single photon emission computed tomography has rarely been investigated. The aim of our study was to evaluate the interpretive reproducibility with this technique. METHODS AND RESULTS: We report on 507 patients with known or suspected stable angina who were studied before coronary angiography. A 1-day thallium 201/technetium 99m sestamibi rest/stress MPI protocol was used. MPI was interpreted by 2 independent observers without knowledge of clinical data, using a 20-segment scoring model. By consensus, the overall rate of abnormal MPI was 49% (59% in men and 34% in women). The interobserver agreement for the whole group (kappa = 0.85) and for men and women separately (kappa = 0.86 and 0.82, respectively) was excellent with regard to the overall diagnosis (normal, reversible, or fixed defects) as well as left anterior descending and left circumflex artery vascular territories (kappa = 0.85 and 0.82, respectively). However, in the right coronary artery territory, agreement was excellent in men (kappa = 0.83) but moderate in women (kappa = 0.57). CONCLUSIONS: In a relatively large group of men and women with stable angina pectoris, interpretive reproducibility (overall and individual vessel diagnosis) was excellent, except in the right coronary artery territory of women, in which it was moderate.