Israel Medical Association Journal

Background: While patients presenting to emergency departments (ER) with chest pain are increasingly managed in chest pain units (CPU) that utilize accelerated diagnostic protocols for risk stratification, such as single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI), data are lacking regarding the prognostic implications of mildly abnormal scans in this population.

Objectives: To evaluate the prognostic implications of mildly abnormal SPECT MPI results in patients with acute chest pain.

Methods: Of the 3753 chest pain patients admitted to the CPU at the Leviev Heart Center, Sheba Medical Center 1593 were further evaluated by SPECT MPI. Scans were scored by extent and severity of stress-induced perfusion defects, with 1221 patients classified as normal, 82 with myocardial infarction without ischemia, 236 with mild ischemia, and 54 with more than mild ischemia. Mild ischemia patients were further classified to those who did and did not undergo coronary angiography within 7 days.

Results: Mild ischemia patients who underwent coronary angiography were more likely to be male (92% vs. 81%, P = 0.01) and to have left anterior descending ischemia (67% vs. 42%, P = 0.004). After 50 months, these patients returned less often to the ER with chest pain (53% vs. 87%, P < 0.001) and had a lower combined endpoint of acute coronary syndrome and death (8% vs. 16%, P < 0.001).

Conclusions: Compared to patients with chronic stable angina, patients presenting with acute chest pain exhibiting mildly abnormal SPECT MPI findings should perhaps undergo a more aggressive diagnostic and therapeutic approach.

Background: Medical evaluation of a suspected meniscus injury begins with a history-taking and physical examination. Suspected meniscus injuries not responding to treatment are usually sent for imaging to confirm the diagnosis before arthroscopy. Tc-MDP bone single photon emission computed tomography (SPECT) scan has been suggested as an alternative to magnetic resonance imaging (MRI) in evaluating suspected knee meniscus tears.

Objectives: To examine the accuracy of knee SPECT as a tool to identify meniscus tears versus that of MRI as compared to the gold standard of arthroscopy.

Methods: The Israel Defense Forces database for 2005 through 2009 was searched according to the key words knee MRI, knee SPECT and knee arthroscopy. We identified 330 subjects who had undergone both a single knee SPECT and a single knee MRI prior to knee surgery. The medical files of 193 of the 330 subjects were randomly selected for review. A comparison was made between the preoperative SPECT and MRI studies and the arthroscopic finding. The sensitivity, specificity and accuracy were calculated.

Results: The subjects’ age was 21.3 ± 3.9. The agreement between SPECT and arthroscopy was 0.14 for the medial meniscus and 0.29 for the lateral meniscus. The agreement between MRI and arthroscopy was 0.59 for the medial meniscus and 0.69 for the lateral meniscus. SPECT scan was found to be 61% sensitive, 54% specific and 58% accurate in detecting common knee pathology, whereas MRI was found to be 95% sensitive, 67% specific and 85% accurate.

Conclusions: Knee SPECT has a lower sensitivity, specificity and accuracy than MRI in evaluating meniscal injuries and its use can result in increased unnecessary surgery.

Background: The evaluation of hospitalized patients with chest pain and non-diagnostic electrocardiogram is problematic and the optimal cost-effective strategy for their management controversial.

Objectives: To determine the utility of myocardial perfusion imaging with thallium-201 for predicting outcome of hospitalized patients with chest pain and a normal or non-diagnostic ECG.

Methods: On pain cessation, 109 hospitalized patients, age 61+14 years (mean+SD), with chest pain and non-diagnostic ECG underwent stress myocardial perfusion SPECT imaging with thallium-201. Costs related to their management were calculated. The occurrence of non-fatal myocardial infarction or cardiac death was recorded at 12+5 months follow-up.

Results: A normal SPECT was found in 84 patients (77%). During one year follow-up, only 1 (1.2%) compared to 7 (28%) cardiac events (6 myocardial infarctions, 1 cardiac death) occurred in patients with normal versus abnormal scans respectively (P < 0.0001). Negative predictive value and accuracy of the method were 99% and 83% respectively. Multivariate regression analysis identified an abnormal SPECT as the only independent predictor of adverse cardiac event (P = 0.0016). Total cost from admission until discharge was 11,193 vs. 31,079 shekels (P < 0.0001) for normal and abnormal scan. Considering its high negative predictive value, shortening the hospital stay from admission until scan performance to 2 days would result in considerably reduced management costs (from NIS 11,193 to 7,243) per patient.

Conclusion: Stress SPECT applied to hospitalized patients with chest pain and a normal or non-diagnostic ECG is safe, highly accurate and potentially cost effective in distinguishing between Iow and high risk patients.