Brief Article
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World J Cardiol. Mar 26, 2013; 5(3): 54-59
Published online Mar 26, 2013. doi: 10.4330/wjc.v5.i3.54
Myocardial perfusion imaging in patients with a recent, normal exercise test
Ann Bovin, Ib C Klausen, Lars J Petersen
Ann Bovin, Department of Clinical Physiology, Viborg Hospital, DK-8800 Viborg, Denmark
Ib C Klausen, Department of Cardiology, Viborg Hospital, DK-8800 Viborg, Denmark
Lars J Petersen, Department of Nuclear Medicine, Aalborg University Hospital, DK-9000 Aalborg, Denmark
Author contributions: Bovin A and Petersen LJ designed the research; Bovin A, Klausen IC and Petersen LJ performed the research; Bovin A and Petersen LJ analyzed the data; Bovin A and Petersen LJ wrote the paper; and Bovin A, Klausen IC and Petersen LJ reviewed the paper and approved the final version.
Correspondence to: Lars J Petersen, Professor, Department of Nuclear Medicine, Aalborg Hospital, Hobrovej 18-22, DK-9100 Aalborg, Denmark. lajp@rn.dk
Telephone: +45-9-9326373 Fax: +45-9-9323145
Received: December 10, 2012
Revised: February 10, 2013
Accepted: March 6, 2013
Published online: March 26, 2013
Processing time: 106 Days and 1.3 Hours
Abstract

AIM: To investigate the added value of myocardial perfusion scintigraphy imaging (MPI) in consecutive patients with suspected coronary artery disease (CAD) and a recent, normal exercise electrocardiography (ECG).

METHODS: This study was a retrospective analysis of consecutive patients referred for MPI during a 2-year period from 2006-2007 at one clinic. All eligible patients were suspected of suffering from CAD, and had performed a satisfactory bicycle exercise test (i.e., peak heart rate > 85% of the expected, age-predicted maximum) within 6 mo of referral, their exercise ECG was had no signs of ischemia, there was no exercise-limiting angina, and no cardiac events occurred between the exercise test and referral. The patients subsequently underwent a standard 2-d, stress-rest exercise MPI. Ischemia was defined based on visual scoring supported by quantitative segmental analysis (i.e., sum of stress score > 3). The results of cardiac catheterization were analyzed, and clinical follow up was performed by review of electronic medical files.

RESULTS: A total of 56 patients fulfilled the eligibility criteria. Most patients had a low or intermediate ATPIII pre-test risk of CAD (6 patients had a high pre-test risk). The referral exercise test showed a mean Duke score of 5 (range: 2 to 11), which translated to a low post-exercise risk in 66% and intermediate risk in 34%. A total of seven patients were reported with ischemia by MPI. Three of these patients had high ATPIII pre-test risk scores. Six of these seven patients underwent cardiac catheterization, which showed significant stenosis in one patient with a high pre-test risk of CAD, and indeterminate lesions in three patients (two of whom had high pre-test risk scores). With MPI as a gate keeper for catheterization, no significant, epicardial stenosis was observed in any of the 50 patients (0%, 95% confidence interval 0.0 to 7.1) with low to intermediate pre-test risk of CAD and a negative exercise test. No cardiac events occurred in any patients within a median follow up period of > 1200 d.

CONCLUSION: The added diagnostic value of MPI in patients with low or intermediate risk of CAD and a recent, normal exercise test is marginal.

Keywords: Single photon emission tomography; Ischemic heart disease; Myocardial perfusion imaging; Pre-test risk; Post-test risk; Added value; Exercise electrocardiography