Duke treadmill score (DTS) and gated single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) in chest pain patient initial experience

Background: Risk stratification of the patient with suspected or known coronary artery disease(CAD)by means of non-invasive testing are highly relevant in clinical cardiology for the selection of patient who require further diagnostic or therapeutic investigation. Aim: To predict severity of myocardial ischaemia by exercise tolerance test (ETT) determined duke treadmill score (DTS) and myocardial perfusion study. Material and methods: A total of 108 (92-men) patients presenting with Canadian cardiovascular society (CCS) class Mil severity of chest pain, mean age 49.88+8.44 yrs, were studied during October 2002-march 2003. All patient underwent ETT and SPECT-MPI scan using Tc-99m-tetrofosmin in one-day stress and rest protocol. Coronary angiogram (CAG) was done within six months of the perfusion study. After performing ETT, patients were categorized by DTS, myocardial perfusion studies were also stratified according to severity of perfusion defect. The angiographic findings (significant>50% stenosis) and perfusion defects in MPI were compared with the severity of DTS. Result: In high DTS group 91.66% patients had perfusion defect, whereas in intermediate and low risk group it was 60% and 40.90% respectively. In high DTS group 91.66% of patient had angiographically proven CAD, 58.33% of them had triple vessel disease (TVD) while in intermediate and low risk group angiographically proven CAD were 65% and 22.27% of whom TVD only in 15% and 0% respectively. Conclusion: The results of ETT using DTS score satisfactorily correlate with SPECT-MPI scanning in high DTS subsets of patients .So it is suggested that patient of high risk DTS could undergo CAG for further evaluation without radio-nuclide perfusion study. Intermediate and low risk needs myocardial perfusion imaging study to guide for further evaluation. (authors)