Can Advanced Physiological Testing Bridge the Gap Between Chest Pain and Nonobstructive Coronary Atherosclerosis?

E valuation of chest pain can be one of the most challenging scenarios faced by cardiologists. The differential diagnosis of chest pain includes myocardial ischemia and pericardial, musculoskeletal, gastrointestinal, pulmonary, or psychologically related syndromes. Our current diagnostic pathway includes the clinical history in the context of the cardiovascular risk factors, noninvasive stress testing, or computed tomography angiography, followed by invasive coronary angiography when these tests indicate significant ischemia. Yet 30% to 50% of patients who undergo angiography are found to have nonobstructive epicardial disease (1). This high rate of nonobstructive disease seen on angiography is often attributed to false-positive stress test results and is sometimes considered a failure of our clinical processes. For some patients, the “negative” angiography allows reassurance and pursuit of nonischemic causes of chest pain. Other patients with persistent chest pain and nonobstructive disease frequently present to emergency departments, requiring recurrent evaluation. Among patients with persistent chest pain and nonobstructive disease, those with compelling