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Left ventricular (LV) cavity dilation during stress myocardial perfusion imaging has been associated with multivessel disease, and may be an independent prognostic marker in addition to perfusion defects. The present study examines the predictive value for future cardiac events of transient or fixed LV dilation during dipyridamole technetium-99m (Tc-99m) sestamibi single-photon emission computed tomography (SPECT) imaging. The study included 512 consecutive patients who underwent SPECT imaging with Tc-99m sestamibi after dipyridamole infusion. Transient LV dilation was seen in 70 patients (14%) and 74 had fixed cavity dilation (14%); cavity size was normal in 368 patients (72%). Each perfusion scan was classified as normal or abnormal, and if abnormal, defects were categorized as transient or fixed, and as small, medium, or large (depending upon the number of abnormal vascular territories). Events during a mean follow-up of 12.8 +/- 6.8 months were tabulated by direct review of hospital charts and death certificates. The cardiac event rate (cardiac death or nonfatal infarction) was 1.9% in patients with normal cavity size, 11.4% with transient LV dilation, and 13.5% with fixed LV dilation (p < 0.01). Compared with patients with normal cavity size, those with transient LV dilation were more likely to sustain a myocardial infarction (p < 0.01) and those with fixed dilation more frequently suffered cardiac death (p < 0.01) and hospitalization for heart failure (p < 0.01). The group with the highest risk had both a large perfusion defect and cavity dilation. By Cox proportional hazard regression analysis, both transient and fixed LV dilation were strong independent predictors of cardiac events. Transient or fixed LV dilation are commonly seen during dipyridamole Tc-99m sestamibi SPECT imaging (14% incidence for each) and are useful predictors of cardiac events.

To evaluate the effectiveness of published nuclear cardiology training guidelines, the diagnostic accuracy of image interpretation by nuclear cardiology trianees was compared with that of experienced nuclear cardiologists. The accuracy of three experienced nuclear cardiologists and three trainees with level II experience following Society of Nuclear Medicine/American College of Cardiology/American Society of Nuclear Cardiology guidelines in the interpretation of 114 exercise 99mTc-labeled sestamibi single-photon emission computed tomographic imaging studies was evaluated. Studies were selected randomly and included patients with less than 5% likelihood of coronary artery disease, as well as patients with angiographically demonstrated single and multivessel disease. Studies were interpreted by each reader without knowledge of clinical or exercise data. Each reader classified perfusion as normal or abnormal. Accuracy was assessed according to sensitivity, normalcy rate, and predictive accuracy. In addition, the ability of experienced readers and trainees to identify abnormal perfusion in patients with multivessel disease was compared. Trainees had high accuracy, comparable to experienced readers for sensitivity, normalcy rate, and predictive accuracy, as well as the ability to identify abnormal perfusion in patients with multivessel disease. In all categories, experienced interpretors demonstrated a trend toward greater accuracy with less observer variability than did trainees. Structured training in nuclear cardiology following Society of Nuclear Medicine/American College of Cardiology/American Society of Nuclear Cardiology guidelines during clinical cardiology fellowship is effective, and trainees possess the skills to interpret myocardial perfusion images accurately. Interpretive skills can be expected to improve further with experience.

Objectives.This study sought to establish the prognostic value of intravenous dipyridamole technetium-99m (Tc-99m) sestamibi single-photon emission computed tomographic (SPECT) myocardial perfusion imaging.Background.Optimal management of patients with coronary artery disease involves strategies designed to reduce the risk of myocardial infarction and cardiac death. The role of myocardial perfusion imaging using newer clinical techniques to determine risk and possible benefit from therapy has not been evaluated.Methods.Myocardial imaging results were classified as normal or abnormal (fixed or reversible defects; small, moderate or large). Follow-up evaluation of all patients included the occurrence of cardiac death or nonfatal myocardial infarction and other cardiac-related hospital admissions.Results.During a mean (±SD) follow-up period of 12.8 ± 6.8 months in 512 patients, 25 had a cardiac event. Patients with abnormal perfusion had significantly more cardiac events than those with normal perfusion (22 vs. 3, p < 0.01). Patients with reversible defects had the highest event rates (8.6%), and those with normal study results had a very low event rate (1.4%). Large defects were strongly associated with more cardiac events and hospital admissions than either normal scan results or abnormal results showing small defects.Conclusions.Patients with normal study results or a small defect after intravenous dipyridamole Tc-99m sestamibi SPECT imaging had an excellent short-term prognosis. Those with abnormal results (reversible or large defect) had an increased risk of subsequent cardiac death, nonfatal myocardial infarction and other cardiac-related hospital admissions.

To evaluate the effectiveness of structured nuclear cardiology training. the reproducibility and accuracy of image interpretation by nuclear cardiology faculty and senior cardiology fellows were compared. The reproducibility and accuracy of 3 faculty and 3 trainees with 6 months training following Nuclear Regulatory Commission/American College of Cardiology guidelines were assessed using 138 exercise Tc-99 m Sestamibi SPECT studies. Studies were randomly selected and included patients with l 5% likelihood of CAD as well as patients with angiographically demonstrated single and multivessel disease. Studies were interpreted twice by each reader without knowledge of clinical or exercise data. Each reader classified perfusion as normal (N) or abnormal (AB). AB perfusion was further classified as fixed (F) or ischemic (I). Reproducibility was compared with respect to first order (N vs AB) and second order (N vs F vs I) intra and inter observer agreement and assessed using percent agreement (%) and Cohen's kappa. Accuracy was assessed using sensitivity and normalcy rate and compared using percent agreement and Cohen's kappa. Trainees Faculty % kappa % kappa Reproducibility First order Intra: 89 0.78 92 0.82 inter: 80 0.59 86 0.71 * Second order intra: 81 0.66 87 0.74 * inter: 69 0.46 82 0.64 * Accuracy Sensitivity 82 87 Normalcy Rate 85 89 % agreement/kappa 83 063 87 0.73 * * p l 0.05 compared with trainees Trainees had high reproducibility and accuracy. comparing favorably with faculty in all categories. Faculty had significantly higher results in several categories. Conclusion Structured training in nuclear cardiology following Nuclear Regulatory Commission/American College of Cardiology guidelines during clinical cardiology fellowship is very effective. resulting in high reproducibility and accuracy. Interpretive skills can be expected to further improve with experience.