Rupa Mehta

Evaluation of the American College of Cardiology Foundation/American Society of Nuclear Cardiology appropriateness criteria for SPECT myocardial perfusion imaging.

Background. The American College of Cardiology Foundation/American Society of Nuclear Cardiology appropriateness criteria (AC) were created to guide responsible use of single photon emission computed tomography (SPECT). Clinical applicability of the AC has not been evaluated.Methods and Results. Indications for testing were determined in 1209 patients and categorized as having appropriate, uncertain, or inappropriate indications; the specialty of the ordering physician was noted. There were 940 (80%) appropriate, 154 (13%) inappropriate, and 79 (7%) uncertain tests; 36 tests were labeled “no category,” as these were ordered for indications not clearly addressed in the AC. Inappropriate studies had more normal and lower summed stress scores, although there remained a high proportion of abnormal SPECT studies in this group (26% of women and 50% of men). Women had lower summed stress scores and more normal tests in the appropriate and inappropriate groups. Studies ordered by anesthesiologists for preoperative evaluation were more likely to be deemed inappropriate than other specialty groups.Conclusion. In evaluating the AC in a single-center academic setting, the majority of studies are appropriate, but a large proportion of ordered SPECT studies were categorized as uncertain, inappropriate, or no category. Although the inappropriate studies showed less ischemia than other groups, especially in women, a substantial portion of these studies (32%) were abnormal.

Prospective evaluation of the clinical application of the American College of Cardiology Foundation/American Society of Echocardiography Appropriateness Criteria for transthoracic echocardiography.

We sought to prospectively evaluate the clinical application of the American College of Cardiology Foundation/American Society of Echocardiography Appropriateness Criteria (AC) for transthoracic echocardiography in a single-center university hospital. Indications for transthoracic echocardiograms (TTE) were prospectively determined for consecutive studies by 2 reviewers and categorized, according to the AC for TTE, as appropriate (A) or inappropriate (I). The overall level of agreement in characterizing appropriateness between reviewers was high (kappa = 0.83). Among the 1,553 studies for which a primary indication was determined, 89% were covered in the AC for TTE. Of these studies, 89% were A, and 11% were I. New important TTE abnormalities were more common on A compared with I studies (40% vs. 17%, p < 0.001), and noncardiac specialists more frequently ordered I studies (13% vs. 9%, p = 0.04). In conclusion, the AC for TTE encompasses the majority of clinical indications for TTE and appears to reasonably stratify TTE ordering. However, revisions will be needed to fully capture and stratify appropriate clinical practice.

Volumetric quantification of myocardial perfusion using analysis of multi-detector computed tomography 3D datasets: comparison with nuclear perfusion imaging

BackgroundAlthough the ability of multi-detector computed tomography (MDCT) to detect perfusion abnormalities associated with acute and chronic myocardial infarction (MI) has been demonstrated, this methodology is based on visual interpretation of selected 2D slices.ObjectivesWe sought to develop a new technique for quantitative volumetric analysis of myocardial perfusion from 3D datasets and test it against resting nuclear myocardial perfusion imaging (NMPI) reference.MethodsWe studied 44 patients undergoing CTCA: a control group of 15 patients and a study group of 29 patients. MDCT datasets acquired for CTCA were analyzed using custom software designed to: (1) generate bull’s eye display of myocardial perfusion and (2) calculate a quantitative index of extent and severity of perfusion abnormality, QH, for 16 volumetric myocardial segments. Visual interpretation of MDCT-derived bull’s eyes was compared with rest NMPI scores using kappa statistics of agreement on a coronary territory and patient basis. Quantitative MDCT perfusion data were correlated with rest NMPI summed scores and used for objective detection of perfusion defects.ResultsVisual analysis of MDCT-derived bull’s eyes accurately detected perfusion defects in agreement with NMPI (kappa = 0.70 by territory; 0.79 by patient). Quantitative data were in good agreement with NMPI, as reflected by: (1) correlation of 0.87 (territory) and 0.84 (patient) between summed QH and NMPI scores, (2) area under ROC curve 0.87 with sensitivity of 0.79–0.92, specificity 0.83–0.91, and accuracy 0.83–0.89 for objective detection of abnormalities.ConclusionsOur new technique for volumetric analysis of 3D MDCT images allows accurate objective detection of perfusion defects. This perfusion information can be obtained without additional radiation or contrast load, and may aid in elucidating the significance of coronary lesions.

SPECT myocardial perfusion imaging with prone-only acquisitions: correlation with coronary angiography

BackgroundRecent evidence suggests that combining supine and prone acquisitions during stress-gated SPECT myocardial perfusion imaging (MPS) improves detection of obstructive coronary artery disease (CAD), though the additional imaging time required may not be feasible in routine clinical practice. MPS with prone-only acquisitions is occasionally performed in many laboratories, though little is known about the ability of modern MPS with prone-only acquisitions to detect obstructive CAD. Our goal was to assess the ability of MPS with prone-only acquisitions to detect obstructive CAD as determined by coronary angiography.Methods and ResultsWe studied 386 patients referred for MPS with either recent coronary angiography or a low pretest likelihood of coronary artery disease. All rest and stress images were obtained exclusively in the prone position. The sensitivity of prone-only MPS was 88% for detecting ≥50% coronary artery stenosis and 92% for detecting ≥70% coronary artery stenosis as determined by coronary angiography. Normalcy rate for prone-only MPS in patients with low probability for CAD was 95%, and normalcy rates did not significantly differ among coronary artery distributions.ConclusionsThe findings of this study suggest that MPS using prone-only acquisitions is a reasonable diagnostic option for the detection of ischemia due to obstructive coronary artery disease.

Takotsubo Cardiomyopathy in a Patient With Squamous Cell Esophageal Carcinoma

Introduction Takotsubo cardiomyopathy (TCM), also known as transient left ventricle (LV) apical ballooning syndrome or stress induced cardiomyopathy, is a rare, although increasingly reported form of cardiomyopathy. ECG changes often times mimic an acute myocardial infarction, but coronary angiography typically reveals nonobstructing lesions ( 50% stenosis). This syndrome has been found to be much more common in women (approximately 88% of cases), and commonly presents with chest pain and dyspnea. It is usually preceded by physical or emotional stress. A MEDLINE database search via Pubmed revealed a total of 54 articles when the terms takotsubo and cancer were paired. Most cases were associated with catecholamine excreting neoplasms (eg, a pheochromocytoma). Only two of the cases were reported in patients with esophageal cancer. We contribute a case of a 69-year-old woman with esophageal cancer that subsequently developed TCM.

AUC for SPECT: Is gender bias inappropriate

The appropriate use criteria (AUC) were created to guide physicians on ordering practices in various clinical scenarios. Most cardiologists are now somewhat familiar with the AUC but have not yet incorporated them into their clinical practice. The American College of Cardiology (ACC) has created the FOCUS Campaign to increase use of the AUC with a commitment to reduce the incidence of inappropriate imaging in the next few years. In addition, lab accreditation will now require an evaluation of appropriateness, further stressing the importance of incorporating the AUC into the clinical setting. It has already been demonstrated that there are numerous challenges to incorporating the AUC into the clinical arena including: (1) obtaining all of the necessary information to categorize patients, whether this is done at point of ordering or point of service, (2) definitions of angina vary amongst practitioners, and (3) training lab personnel to use the AUC and to categorize patients properly. As clinicians, we can appreciate that many patients do not easily fit into a particular category and that clinical judgment plays a significant role in when and why we order a particular test. There are subsets of patients that have already been shown to have high rates of inappropriate testing. This includes asymptomatic patients and women. In fact, the most common inappropriate indications are in asymptomatic patients. To further guide clinical decision making in this subset of patients, the American Society of Nuclear Cardiology has recently published an information statement on the use of single perfusion computed tomography myocardial perfusion imaging (SPECT MPI) in asymptomatic patients. There is, however, a paucity of data regarding the AUC in women. In this issue of the Journal of Nuclear Cardiology, Gupta et al investigated gender disparity in the use of the appropriateness criteria. They had several notable findings. They found that inappropriate studies were more likely to be ordered in women than in men (68% vs 32%). The average age of women in the inappropriate group was 48 ± 9 years. Uncertain studies were also more likely to be ordered in women than in men (82% vs 18%) with an average age of women in this group of 47 ± 6 years. The average age of the total cohort was 62 ± 14 years. Younger patients were more likely to have inappropriate or uncertain studies as would be expected with a lower-risk patient. It would have been informative if the study had indicated what portion of these inappropriate studies was normal. They mention that 8 studies in the inappropriate and uncertain groups had high-risk test results but do not comment on the degree of abnormality. Their data supports previously published data by Mehta et al that women are more likely to have an inappropriate study (74% vs 26%). Mehta et al also showed that normal studies are more frequent in women than in men that were ordered for inappropriate indications. However, they also noted that a quarter of women in the inappropriate group and almost half of the women in the uncertain group had SPECT abnormalities. When abnormal, women in the inappropriate and appropriate groups had lower summed stress scores (smaller defects) than men. Although these results show lower summed stress scores, the presence of an abnormal result could potentially alter medical management in a patient with no prior history of CAD. Downstream changes could include the addition of aspirin, a statin or more aggressive risk factor reduction through lifestyle modifications. Gupta et al report that women undergoing SPECT MPI have a relative risk of 2.69 that the test will be classified as inappropriate and a relative risk of 6.0 that the test will be classified as uncertain with all other factors being equal. Hendel et al have also shown in a multi-center study that female sex is an independent risk factor for receiving an inappropriate classification, increasing the likelihood of being considered inappropriate by 2.5 times for women compared to men even From the Section of Cardiology, Department of Medicine, University of Chicago Medical Center, Chicago, IL; Division of Cardiology, Wayne State University School of Medicine, Detroit, MI, USA. Reprint requests: Rupa Mehta, MD, Section of Cardiology, Department of Medicine, University of Chicago Medical Center, 5841 S. Maryland, MC 2090, Chicago, IL 60638; rmehta@medicine. bsd.uchicago.edu. J Nucl Cardiol 2011;18:538–40. 1071-3581/

American Society of Nuclear Cardiology review of the ACCF/ASNC appropriateness criteria for single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI).

34.00 Copyright 2011 American Society of Nuclear Cardiology. doi:10.1007/s12350-011-9374-z