The pattern of findings by stress myocardial perfusion spect scan in suspected or known coronary artery disease Nairobi experience

Abstract

Context: Coronary artery disease (CAD) is a major cause of morbidity and mortality in the developed world. This has also been found to be true in the developing countries although minimal statistics are available to support this. Objective: To establish the demographics, common clinical presentation and predictive value of stress myocardial perfusion Single Photon Emission Computerized Tomography .( SPECT) scan in suspected and known CAD in Nairobi and thus describe its role in management of the same. Design: Prospective study from April 2005 - February 2006. Methodology and participants: Single day stress- rest protocol with SPECT acquisition using 99m Tc- tetrofosmin was carried out on all patients referred for this investigation by their primary care physician. A correlation of the perfusion scan findings with angiographic data (where available) and clinical follow-up, was made. The clinical end points were furnished by referring physicians. Results: There was a male preponderance (65.7%) with the mean age of presentation being 60 years and standard deviation 11.4..Male: Female was 1.9:1. Chest pain and abnormal stress electrocardiogram (ECG) were the common reasons for referral for nuclear perfusion imaging. Of the patients studied 66.7% showed concordance of the myocardial perfusion scan and angiographic findings. In reference to clinical outcome, myocardial perfusion SPEer scan had a sensitivity of93.5% and a specificity of97.5%. Positive predictive value of SPECT was 83.3% and its negative predictive value was 50% in this study. Conclusion: Stress myocardial perfusion SPECT scan is a valuable non-invasive imaging modality in assessment of coronary artery disease which has a good sensitivity and specifity and correlates with clinical outcome data. It reliably assesses the likelihood of a future cardiac event.