The prognostic value of myocardial perfusion scintigraphy compared to coronary angiography in women with positive stress test results.

BACKGROUND

Modern diagnostic strategy in coronary artery disease (CAD) makes it necessary not only to establish a diagnosis but also to assess the cardiovascular risk. It is not clear which strategy should be followed in the case of women with positive ECG stress test results to assess prognosis and start appropriate diagnostics and treatment.The aim of the study was to assess the prognostic value of myocardial perfusion scintigraphy in comparison with coronary angiography in women suspected of CAD and with positive ECG stress test results.

MATERIAL AND METHODS

The study population comprised 115 women (mean age 58.08 ± 8.8 years) suspected of CAD, with a history of chest pain and positive stress test results, who underwent myocardial perfusion scintigraphy. In 58 women coronary angiography was performed as the next step of the diagnostic procedure. All the patients were interviewed and had a physical examination, including the assessment of the cardiovascular risk in accordance with the SCORE (Systematic Coronary Risk Evaluation) scale and the probability of CAD (POST-TEST) in accordance with the ESC guidelines. The gated single photon emission computed tomography (GSPECT) with Tc-99m-MIBI was considered positive if moderate perfusion changes were observed in at least two segments or severe reversible perfusion disorders were found, regardless of the number of involved segments.The degree of coronary stenosis was assessed visually and changes greater than 50% stenosis of the luminal diameter were considered haemodynamically significant.

RESULTS

The evaluation period covered 43.2 ± 30.8 months on average. The sensitivity of myocardial perfusion scintigraphy against cardiovascular events was 100% and the sensitivity of coronary angiography was 92.3%. The specificity was 93.1%and 88.9% respectively. The PPV of scintigraphy for cardiovascular events was 65% and of coronary angiography was 70.6%. The NPV was 100% and 97.6%respectively. The accuracy of myocardial perfusion scintigraphy for cardiovascular events was 93.9% and the accuracy of coronary angiography for cardiovascular events was 89.7%. The survival analysis confirmed the high prognostic value of SPECT and coronary angiography. However, if compared, myocardial perfusion scintigraphy was a better predictor of survival without cardiovascular events than coronary angiography was (c2 = 9.39, p < 0.01).The most important factors in assessing the cardiovascular risk in the study population included: positive result of myocardial perfusion scintigraphy, positive result of coronary angiography,and high SCORE and high POST-TEST values.

CONCLUSIONS

Myocardial perfusion scintigraphy is superiorto coronary angiography in the prediction of necessary revascularisation procedures in women suspected of coronary artery disease and with positive stress test results.