Myocardial Blood Flow and Flow Reserve in Proximal and Mid-to-Distal Lesions of Left Anterior Descending Artery Measured By N-13 Ammonia PET/CT

Multimodality Imaging for Spontaneous Coronary Artery Dissection in Women

Spontaneous coronary artery dissection (SCAD) has gained attention as a key cause of acute coronary syndrome and sudden cardiac death among women. Recent advancements in cardiac imaging have improved identification and accelerated awareness of SCAD. Accurate diagnosis of SCAD through use of imaging is critical, as emerging evidence suggests that the optimal short- and long-term management strategies for women with SCAD differs substantially from that of women with atherosclerotic coronary disease. This review summarizes the application of both invasive and noninvasive imaging for the diagnosis, assessment, surveillance, and treatment of women affected by SCAD.

Impaired coronary flow reserve is the most important marker of viable myocardium in the myocardial segment-based analysis of dual-isotope gated myocardial perfusion single-photon emission computed tomography

OBJECTIVE

The aim of this study was to investigate the most robust predictor of myocardial viability among stress/rest reversibility (coronary flow reserve [CFR] impairment), (201)Tl perfusion status at rest, (201)Tl 24 hours redistribution and systolic wall thickening of (99m)Tc-methoxyisobutylisonitrile using a dual isotope gated myocardial perfusion single-photon emission computed tomography (SPECT) in patients with coronary artery disease (CAD) who were re-vascularized with a coronary artery bypass graft (CABG) surgery.

MATERIALS AND METHODS

A total of 39 patients with CAD was enrolled (34 men and 5 women), aged between 36 and 72 years (mean 58 ± 8 standard in years) who underwent both pre- and 3 months post-CABG myocardial SPECT. We analyzed 17 myocardial segments per patient. Perfusion status and wall motion were semi-quantitatively evaluated using a 4-point grading system. Viable myocardium was defined as dysfunctional myocardium which showed wall motion improvement after CABG.

RESULTS

The left ventricular ejection fraction (LVEF) significantly increased from 37.8 ± 9.0% to 45.5 ± 12.3% (p < 0.001) in 22 patients who had a pre-CABG LVEF lower than 50%. Among 590 myocardial segments in the re-vascularized area, 115 showed abnormal wall motion before CABG and 73.9% (85 of 115) had wall motion improvement after CABG. In the univariate analysis (n = 115 segments), stress/rest reversibility (p < 0.001) and (201)Tl rest perfusion status (p = 0.024) were significant predictors of wall motion improvement. However, in multiple logistic regression analysis, stress/rest reversibility alone was a significant predictor for post-CABG wall motion improvement (p < 0.001).

CONCLUSION

Stress/rest reversibility (impaired CFR) during dual-isotope gated myocardial perfusion SPECT was the single most important predictor of wall motion improvement after CABG.