Left main disease diagnosis: The Achilles heel or the great strength of modern cardiac imaging?

Coronary "balanced ischemia" with false negative regadenoson Technetium Tc99 m Sestamibi stress test subsequently diagnosed by FFRCT

A 63-year-old female with multiple cardiovascular risk factors presented with a nontypical chest pain syndrome. Myocardial perfusion imaging (MPI) with a regadenoson (Lexiscan) Technetium Tc99 m (Sestamibi) stress test was interpreted as normal. The patient's chest pain syndrome continued, and subsequently, she presented to the emergency room. Cardiac computed tomographic angiography (CCTA) revealed a partially calcified left main coronary artery (LMCA) plaque with mild positive remodeling, having low attenuation (68 Hounsfield units-HU) in the noncalcified portion. In addition, a significant proximal left anterior descending coronary artery (LAD) noncalcified plaque was also noted. These lesions were hemodynamically significant by CCTA fractional flow reserve (FFR_CT ) as evidenced by a significant drop across the LMCA, followed by the LAD and circumflex (CX) vessels. Stenting of the stenosis was performed with resolution of symptoms. The phenomenon of "balanced ischemia" was not readily detected with a regadenoson Technetium Tc99 m perfusion stress test but was readily documented by FFR_CT .