Timothy M. Bateman

ACCF/ASNC/ACR/AHA/ASE/SCCT/SCMR/SNM 2009 Appropriate Use Criteria for Cardiac Radionuclide Imaging

Peter Alagona, JR, MD, FACC* Timothy M. Bateman, MD, FACC† Manuel D. Cerqueira, MD, FACC, FAHA, FASNC† James R. Corbett, MD, FACC‡ Anthony J. Dean, MD, FACEP§ Gregory J. Dehmer, MD, FACC, FAHA* Peter Goldbach, MD, FACC Leonie Gordon, MB, CHB¶ Frederick G. Kushner, MD, FACC# Raymond Y. Kwong, MD, MPH, FACC** James Min, MD, FACC†† Miguel A. Quinones, MD, FACC‡‡ R. Parker Ward, MD, FACC† Michael J. Wolk, MD, MACC* Scott H. Yang, MD, PHD, FACC*

Guidelines for clinical use of cardiac radionuclide imaging report of the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (Committee on Radionuclide Imaging), developed in collaboration with the American Society of Nuclear Cardiology☆

Abstract It is becoming more apparent each day that despite a strong national commitment to excellence in health care, the resources and personnel are finite. It is therefore appropriate that the medical profession examine the impact of developing technology and new therapeutic modalities on the practice of cardiology. Such analysis, carefully conducted, could potentially affect the cost of medical care without diminishing the effectiveness of that care. To this end, the American College of Cardiology and the American Heart Association in 1980 established a Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures with the following charge: The Task Force of the American College of Cardiology and the American Heart Association shall develop guidelines relative to the role of new therapeutic approaches and of specific noninvasive and invasive procedures in the diagnosis and management of cardiovascular disease. The Task Force shall address, when appropriate, the contribution, uniqueness, sensitivity, specificity, indications, contra-indications and cost-effectiveness of such diagnostic procedures and therapeutic modalities. The Task Force shall emphasize the role and values of the developed guidelines as an educational resource. The Task Force shall include a Chairman and six members, three representatives from the American Heart Association and three representatives from the American College of Cardiology. The Task Force may select ad hoc members as needed upon the approval of the Presidents of both organizations. Recommendations of the Task Force are forwarded to the President of each organization.

Anatomic versus physiologic assessment of coronary artery disease. Role of coronary flow reserve, fractional flow reserve, and positron emission tomography imaging in revascularization decision-making.

Angiographic severity of coronary artery stenosis has historically been the primary guide to revascularization or medical management of coronary artery disease. However, physiologic severity defined by coronary pressure and/or flow has resurged into clinical prominence as a potential, fundamental change from anatomically to physiologically guided management. This review addresses clinical coronary physiology-pressure and flow-as clinical tools for treating patients. We clarify the basic concepts that hold true for whatever technology measures coronary physiology directly and reliably, here focusing on positron emission tomography and its interplay with intracoronary measurements.

Metabolic Imaging With β-Methyl-p-[123I]-Iodophenyl-Pentadecanoic Acid Identifies Ischemic Memory After Demand Ischemia

Background— After myocardial ischemia, prolonged suppression of fatty acid metabolism may persist despite restoration of blood flow, which is called metabolic stunning. We hypothesized that a branched-chain fatty acid, &bgr;-methyl-p-[123I]-iodophenyl-pentadecanoic acid (BMIPP), might identify the presence of myocardial ischemia late after demand ischemia at rest up to 30 hours later. Methods and Results— In 32 patients with exercise-induced ischemia on thallium SPECT, BMIPP was injected at rest within 30 hours of ischemia. SPECT images were acquired beginning 10 minutes after injection (early) and again 30 minutes after injection (delayed). Thallium and BMIPP SPECT data were read separately by 3 observers blinded to other imaging and clinical data. Agreement between BMIPP and thallium data for the presence of an abnormality on the patient level was 91% (95% CI, 75 to 98) for the early BMIPP data and 94% (95% CI, 79 to 99) for the delayed BMIPP data. Agreement between delayed BMIPP and thallium was 95% among 21 patients studied on the same day, a mean of 6.2±1.4 hours after exercise-induced ischemia, and 91% among the 11 patients studied on the next calendar day, a mean of 24.9±2.6 hours after ischemia (P=NS). The magnitude of resting BMIPP metabolic defect by semiquantitative visual analysis was correlated to the magnitude of exercise-induced thallium perfusion defect (r=0.6, P<0.001 for early BMIPP; r=0.5, P=0.005 for delayed BMIPP). Conclusions— Metabolic imaging with BMIPP identifies patients with recent exercise-induced myocardial ischemia. These findings support the concept that BMIPP imaging can successfully demonstrate the metabolic imprint of a stress-induced ischemic episode, also known as ischemic memory.

Treatment of severe platelet dysfunction and hemorrhage after cardiopulmonary bypass: reduction in blood product usage with desmopressin.

Impairment of platelet function commonly occurs after cardiopulmonary bypass, and may result in substantial bleeding. Because desmopressin acetate (a synthetic analogue of vasopressin) shortens bleeding time in a variety of platelet disorders, a controlled clinical trial of intravenous desmopressin was performed in 39 patients with excessive mediastinal bleeding (greater than 100 ml/h) and a prolonged template bleeding time (greater than 10 minutes) more than 2 hours after termination of cardiopulmonary bypass. Twenty-three desmopressin recipients and 16 control patients (no desmopressin) were similar in surgical procedure, pump time, platelet count, template bleeding time and amount of bleeding before therapy (p = NS). Compared with the control group, the patients receiving desmopressin (20 micrograms; mean 0.3 micrograms/kg) utilized fewer blood products (29 +/- 19 versus 15 +/- 13 units/patient; p less than 0.05), especially platelets (12 +/- 9 versus 4 +/- 7 units/patient; p = 0.004), while achieving a similarly effective reduction in mediastinal bleeding (4.8- and 4.3-fold, p = 0.001 for both). Severe platelet dysfunction was partially corrected within 1 hour after desmopressin infusion, during which interval no blood products were administered: the template bleeding time shortened (from 17 to 12.5 minutes, p less than 0.05), whereas the platelet count remained unchanged (at 96 +/- 35 and 105 +/- 31 X 10(3)/mm3, p = NS). The plasma levels of two factor VIII components increased: procoagulant activity (VIII:C) from 0.97 +/- 0.43 to 1.52 +/- 0.74 units/ml (p less than 0.05) and von Willebrand factor (VIII:vWF) from 1.28 to 1.78 units/ml (p less than 0.05); these increases correlated with the shortening of the bleeding time (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The value and practice of attenuation correction for myocardial perfusion SPECT imaging: A joint position statement from the American Society of Nuclear Cardiology and the Society of Nuclear Medicine

ConclusionDespite advancements in technologies, non-uniform soft tissue attenuation still affects the diagnostic accuracy of single photon emission computed tomography (SPECT) myocardial perfusion imaging. A variety of indirect measures have been used to reduce the impact of attenuation, most notably electrocardiography-gated SPECT imaging. However, all available techniques have limitations, making interpretation in the presence of attenuation difficult. The ultimate solution, similar to positron emission tomography imaging, is to use hardware/software algorithms to eliminate attenuation and provide images that are more uniform and easier to interpret. Several attenuation correction solutions are currently available and more will be available soon. The value of these solutions has been varied, particularly with clinical applications. Guidelines and standards clearly are necessary.In recognition of the importance of this issue, the American Society of Nuclear Cardiology and the Society of Nuclear Medicine convened a joint task force to develop a position statement on attenuation correction. It is being published concurrently in the Journal of Nuclear Cardiology and The Journal of Nuclear Medicine, a first for these societies.The purpose of this position statement is to clarify the role of attenuation correction in SPECT procedures, to provide guidelines for its clinical use, and to provide a basis for the evaluation of published validation. It is hoped that this position statement will provide an important and useful road map to the widespread adoption of attenuation correction into clinical practice.

Comparison of stress echocardiography and stress myocardial perfusion scintigraphy for diagnosing coronary artery disease and assessing its severity.

The cumulative published literature dealing with the most frequently utilized noninvasive cardiac stress imaging modalities (radionuclide myocardial perfusion scintigraphy and echocardiography) was reviewed to gain insight on their comparative diagnostic accuracies. To be included, studies had to be performed in conjunction with exercise or a commonly used intravenous pharmacologic stress agent (dipyridamole, adenosine or dobutamine) and had to report temporally related coronary angiography findings. A total of > 75 studies were included, involving > 7,000 patients. Exercise single-photon emitted computed tomographic (SPECT) scintigraphy was more sensitive than exercise echocardiography for detecting coronary artery disease (CAD), localizing it to the proper coronary artery distribution and correctly identifying the presence of multivessel CAD. Adenosine, dipyridamole, and dobutamine provided similar diagnostic accuracy when performed in conjunction with SPECT scintigraphy, and all were more accurate than dobutamine echocardiography. Clinical specificity was similarly high with adenosine SPECT, dipyridamole echocardiography, and exercise echocardiography, and lower with exercise SPECT. Normalcy rate was high for exercise SPECT and similar to clinical specificity for echocardiography.

Regadenoson Induces Comparable Left Ventricular Perfusion Defects as Adenosine A Quantitative Analysis From the ADVANCE MPI 2 Trial

OBJECTIVES This study sought to determine whether regadenoson induces left ventricular perfusion defects of similar size and severity as seen with adenosine stress. BACKGROUND Total and ischemic left ventricular perfusion defect size predict patient outcome. Therefore, it is important to show that newer stressor agents induce similar perfusion abnormalities as observed with currently available ones. METHODS The ADVANCE MPI 2 (Adenosine versus Regadenoson Comparative Evaluation for Myocardial Perfusion Imaging) study was a prospective, double-blind, randomized trial comparing image results in patients undergoing standard gated adenosine single-photon emission computed tomography (SPECT) myocardial perfusion imaging who were then randomized in a 2:1 ratio to either regadenoson (N = 495) or a second adenosine SPECT (N = 260). Quantitative SPECT analysis was used to determine total left ventricular perfusion defect size and the extent of ischemia. Quantification was performed by a single observer who was blinded to randomization and image sequence. RESULTS Baseline gated perfusion results were similar in patients randomized to adenosine or regadenoson. No significant differences in total (11.5 +/- 15.7 vs. 11.4 +/- 15.8, p = 0.88) or ischemic (4.8 +/- 9.2 vs. 4.6 +/- 8.9, p = 0.43) perfusion defect sizes were observed between the regadenoson and adenosine groups, respectively. Linear regression showed a close correlation between adenosine and regadenoson for total (r = 0.97, p < 0.001) and ischemic (r = 0.95, p < 0.001) left ventricular perfusion defects. Serial differences in total (-0.03 +/- 3.89 vs. -0.13 +/- 4.16, p = 0.73) and ischemic (0.15 +/- 4.08 vs. 0.25 +/- 3.81, p = 0.74) perfusion defect size and left ventricular ejection fraction (0.12 +/- 0.32 vs. 0.15 +/- 0.35, p = 0.27) from study 1 to study 2 were virtually identical in patients randomized to regadenoson versus adenosine, respectively. The good correlation between serial adenosine and regadenoson studies regarding total (0.41 +/- 5.43 vs. 0.21 +/- 5.23, p = 0.76) and ischemic (0.17 +/- 5.31 vs. 0.23 +/- 6.08, p = 0.94) perfusion defects persisted in the subgroup of 308 patients with an abnormal baseline SPECT. CONCLUSIONS Applying quantitative analysis, regadenoson induces virtually identical scintigraphic results as adenosine regarding the size and severity of left ventricular perfusion defects and the extent of scintigraphic ischemia.

Agreement of visual estimation of coronary artery calcium from low-dose CT attenuation correction scans in hybrid PET/CT and SPECT/CT with standard Agatston score.

OBJECTIVES We sought to evaluate the accuracy and reproducibility of visual estimation of coronary artery calcium (CAC) from computed tomography attenuation correction (CTAC) scans performed for hybrid positron emission tomography (PET)/computed tomography (CT) and single-photon emission computed tomography (SPECT)/CT myocardial perfusion imaging (MPI). BACKGROUND At the time of MPI, hybrid systems obtain a low-dose, non-electrocardiogram (ECG)-gated CT scan that is used to perform attenuation correction. Utility of this CTAC scan in estimating actual CAC as measured by Agatston score (AS) on standard ECG-gated scans has not been previously studied. METHODS A total of 492 patients, from 3 centers, receiving both MPI with CTAC and a standard CAC scan were studied. At each site, experienced readers blinded to AS reviewed CTAC images, visually estimating CAC on a 6-level scale: classifying patients as estimated AS of 0, 1 to 9, 10 to 99, 100 to 300, 400 to 999, or ≥1,000. Agreement between visually estimated coronary artery calcium (VECAC) on CTAC and AS, measured standardly and converted to the same scale, was evaluated, as was inter-reader agreement. RESULTS Although CTAC images are low dose and nongated, a high degree of association was observed between VECAC and AS, with 63% of VECACs in the same category as the AS category and 93% within 1 category. Weighted kappa was 0.89 (95% confidence interval: 0.88 to 0.91, p < 0.0001). High weighted kappa statistics were observed for each site, scanner type, and sex. Readers reported identical scores in 65% of cases and scores within 1 category in 93%. CONCLUSIONS CAC can be visually assessed from low-dose CTAC scans with high agreement with AS. CTAC scans should be routinely assessed for VECAC.

Diffuse slow washout of myocardial thallium-201: a new scintigraphic indicator of extensive coronary artery disease

When coronary artery disease is extensive and of relatively uniform severity, regional myocardial hypoperfusion may be balanced during stress, precluding development of spatially relative perfusion defects. Assessment of the washout of thallium-201 from myocardial regions may provide diagnostic assistance in these cases because washout analysis is spatially nonrelative and hypoperfused myocardial regions manifest a slow thallium-201 washout rate. In 1,265 consecutive patients having quantitatively analyzed stress-redistribution scintigraphy, 46 had a diffuse slow washout pattern with no or a maximum of one regional perfusion defect. Thirty-two underwent clinically indicated coronary angiography, and 23 (72%) of these were found to have three vessel or left main disease. Of 30 similar patients without a diffuse slow washout pattern and with no or a maximum of one perfusion defect, only 5 (17%) had extensive coronary disease. An independent relation between diffuse slow washout and extensive coronary disease was demonstrated by a Mantel- Haentzel chi-square analysis of a wide variety of other indexes of extensive disease. A diffuse washout abnormality, even in the absence of other scintigraphic, clinical or electrocardiographic indicators, carries a high predictive value for three vessel or left main coronary artery disease. The predictive value is maintained when the exercise level achieved is submaximal. Although an infrequent occurrence (3.6% of tested patients), a diffuse slow washout pattern without other scintigraphic indications of extensive coronary disease should lead to further diagnostic testing.