Physiologic and compositional coronary artery disease extension in patients with takotsubo syndrome assessed using artificial intelligence: an optical coherence tomography study

Abstract

Background Takotsubo syndrome (TTS) is an acute and reversible ventricular motion abnormality without epicardial coronary obstruction. Optical flow ratio (OFR) is an approach to evaluate the coronary stenosis significance based on three-dimensional optical coherence tomography (3D-OCT). The aim of this study is to utilize OCT and an artificial intelligence plaque characterization model to show the prevalence and composition of atherosclerotic disease in coronary vessels of patients with TTS. Methods This is a retrospective and observational study which enrolled patients with TTS who underwent coronary angiography and OCT examination. OCT images were analyzed for tissue characterization and OFR computation using a novel artificial intelligence algorithm. Results A total of 37 patients and 49 vessels were studied. All patients were imaged in the left anterior descending coronary artery (LAD) and about two-thirds were also imaged in the left circumflex coronary artery (LCX). Most patients were women (n = 35), and apical was the most common takotsubo type. Tissue composition analysis yielded the following overall plaque types: fibrous (67.1%), lipid (15.5%), and calcium (3.77%). The mean OFR for LAD and LCX was 0.97 ± 0.04 and 0.98 ± 0.02, respectively. Conclusion Utilizing automatic plaque characterization on OCT images by artificial intelligence, we found that TTS patients have coronary artery disease (i.e. presence of lipid, calcified, or fibrous tissue). The advent of artificial intelligence methods may allow for large-scale studies of patients with TTS.

Coronary artery disease and takotsubo syndrome: pathophysiologic considerations

“…Also, the tissue composition analysis revealed a mean of 67.1% fibrous, 15.5% lipid and 3.77% calcium plaque types, confirming that TTS patients have CAD, in the sense that CAD is present as defined by the presence of lipid, calcified or fibrous tissue. Of note is that, although TTS is traditionally diagnosed in the absence of CAD, or at least obstructive CAD, as identified by coronary angiography, it has been shown repeatedly to be associated with both [2], as also shown in the present study of patients all of whom had nonflow limiting CAD [1]. Indeed, there is an occasional association of TTS with comorbid acute coronary syndromes (ACS) [3].…”

“…ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction and myocardial infarction with nonobstructive CAD). Such comparisons can be accomplished by analyzing patients, who had simultaneous coronary angiography and OCT studies performed, from the authors’ participating single site, from where the iTako registry enrolled patients with TTS for the present study [1].…”

“…To the Editor I read with great interest the contribution of Garcia-Garcia et al [1] about the physiologic (degree of stenosis) and compositional nature (assessment of plaque burden of fibrous or lipid tissue and calcium) of coronary artery disease (CAD) encountered in patients with takotsubo syndrome (TTS). This evaluation was implemented in a retrospective observational study of 37 patients (35 women) and 49 vessels.…”

“…ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction and myocardial infarction with nonobstructive CAD). Such comparisons can be accomplished by analyzing patients, who had simultaneous coronary angiography and OCT studies performed, from the authors' participating single site, from where the iTako registry enrolled patients with TTS for the present study [1]. Some authors have speculated that TTS is pathogenetically associated with coronary vasospasm involving the epicardial and intramural or these 2 and the microvascular component of the coronary circulation, a mechanism explored via acetylcholine testing, early after the inception of TTS [4], although there may be some reservations about such hypothesis [5].…”

“…Some authors have speculated that TTS is pathogenetically associated with coronary vasospasm involving the epicardial and intramural or these 2 and the microvascular component of the coronary circulation, a mechanism explored via acetylcholine testing, early after the inception of TTS [4], although there may be some reservations about such hypothesis [5]. Accordingly, it may be of value to associate physiological and structural characterization of CAD, used by the authors herein [1] with the results of Ach testing (presence or absence of coronary vasospasm) in patients with TTS and those with CAD and ACS. Perhaps, such comparisons may show that patients with TTS, undergoing Ach testing during the first week after the inception of their illness, develop coronary vasospasm at a higher rate than patients with ACS, and such response is associated with fewer calcium plaques, as shown by the authors [1], in comparison with the patients who have suffered ACS in association with CAD, with perhaps more frequent calcium plaques, ensuring in the latter some form of 'coronary scaffolding' preventing coronary vasospasm, and consequently preventing TTS, as previously theorized [4].…”