Area and severity of ischemia according to dynamic single-photon emission computed tomography and myocardial perfusion scintigraphy in patients with multivessel coronary artery disease: comparison with the results of coronary angiography

Aim . To study the relationship between the coronary atherosclerosis involvement area and ischemia severity in terms of the consistency of dynamic single-photon emission computed tomography (SPECT) and myocardial perfusion scintigraphy (MPS) data with coronary angiography in patients with multivessel coronary artery (CAD) disease. Material and methods . The study included 327 patients with suspected or confirmed coronary artery disease (CAD), who previously underwent dynamic SPECT, MPS and invasive or computed tomography coronary angiography. Based on the data on coronary artery (CA) involvement, patients were selected: 1) with multivessel CAD (n=171), 2) with single-vessel CAD (n=71) and 3) non-obstructive CAD (n=85). Based on the MPS data, the presence and impaired perfusion area at rest and during the stress test, as well as the degree of their discrepancy were assessed: summed stress score (SSS), summed rest score (SRS) and summed difference score (SDS). The values of myocardial blood flow (MF) and MF reserve (MFR) were assessed using dynamic myocardial SPECT. Results . Standard MPS indices did not differ between the groups with non-obstructive, single-vessel and multivessel CAD as follows: 2,0 (0,0; 4,0) vs 5,0 (2,0; 7,0) vs 5,0 (3,0; 9,0) — SSS; 0,0 (0,0; 1,0) vs 3,0 (0,0; 5,0) vs 2,0 (0,0; 4,0) — SRS; 2,0 (0,0; 3,0) vs 3,0 (1,0; 6,0) vs 2,0 (0,0; 5,0) — SDS, respectively. The transient ischemic dilation did not differ between the study groups. Dynamic SPECT revealed a decrease (p<0,01) in global stress MF and MFR in patients with multivessel CAD compared to groups with non-obstructive and isolated single-vessel atherosclerosis: 1,07 (0,69; 1,49) vs 1,46 (1,08; 1,88) vs 1,48 (0,93; 1,89); 1,64 (1,16; 2,33) vs 2,28 (1,52; 2,93) vs 2,36 (1,58; 3,07), respectively. Net Reclassification analysis showed that MFR allows for correct reclassification of a significant proportion of patients with CAD compared to MPS (NRI=0,31, p=0,001). Conclusion . Dynamic myocardial SPECT is an adequate tool for assessing the ischemia volume in patients with extensive coronary involvement, and global MFR can be considered as one of the selection criteria for myocardial revascularization. The results obtained in this study require further study.