Reconciling discordant myocardial perfusion imaging and coronary angiography.

A common clinical conundrum presents itself in the discordance between nuclear stress testing and invasive coronary angiography (ICA) in the patient presenting with angina. A patient with an abnormal perfusion scan and "normal coronary angiography" may result in the patient's symptoms being dismissed as "non-cardiac." Alternatively, a patient with a "normal perfusion study," who nonetheless undergoes ICA and is found to have significant coronary artery disease may confound efforts to risk stratify and potentially treat patients with angina. This paper will review the current evidence to explain these apparent paradoxical scenarios.