Myocardial Perfusion Scintigraphy in the Prediction of the Existence of Hemodynamically Significant Coronary Artery Stenosis

Introduction/Aim. Anatomically insignificant stenosis of coronary arteries obtained on coronary angiography, in numerous cases can show hemodynamic significance and as such cause ischemic myocardial changes. The goal was to assess the diagnostic accuracy of myocardial perfusion scintigraphy (SPECT MPI) in the detection of hemodinamically significant coronary artery stenosis in patients with moderate risk for ischemia, without previously detected coronary disease. Patients and methodology. The study included 258 patients, of which 54% females and 46% males, with an average age of 59.0 +/- 10.1 years. SPECT MPI was done by a two-day protocol with 99 mTc-MIBI. The pathological finding was the existence of perfusion defects. The physical stress test was done by Bruce protocol. Coronary angiography (CA) was performed according to a standard protocol in patients with pathological SPECT MPI findings (n = 128). Anatomically significant coronary artery narrowing was > 70%. Stenoses from 30% to 69% were considered hemodynamically significant in patients with reversible perfusion defects on SPECT MPI. Results. The sensitivity (SE) of SPECT MPI was 89%, specificity (SP) 42%, positive predictive value (PPV) 86%, negative predictive value (NPV) 50%, and total diagnostic accuracy (ACC) was 74% when the results were compared with stenosis > 70%. By including stenosis from 30% to 69%, the obtained values of diagnostic indicators of SPECT MPI reliability were: SE 91%; SP 100%; PPV 100%; NPV 50% and ACC 91%. Conclusion. With CA only, it is not possible to prove the existence of hemodynamic significance of coronary artery stenoses from 30% to 69%, which represents a recruitment range for developing ischemia. SPECT MPI shows high SE, SP, PPV, and ACC in detecting the existence of left ventricular myocardium perfusion disorder in either stenosis of coronary arteries with or without anatomically significant value.