Mid-Ventricular Tako-Tsubo Cardiomyopathy With Structurally Normal Coronary Arteries Confirmed by Optical Coherence Tomography

ABSTRACT: Tako-Tsubo cardiomyopathy is an entity of unknown etiology characterized by transient apical dyskinesia in patients with angiographically normal coronary arteries. However, atypical forms of Tako-Tsubo cardiomyopathy may also occur, affecting other myocardial segments. Optical coherence tomography has a unique resolution and may detect angiographically silent atherosclerotic coronary artery disease. In this report, we describe optical coherence tomography findings in a patient with atypical Tako-Tsubo cardiomyopathy presenting as transient mid-ventricular ballooning.

J INVASIVE CARDIOL 2013;25(12):E214-E215

Key words: Tako-Tsubo cardiomyopathy, optical coherence tomography

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Tako-Tsubo (TT) cardiomyopathy is characterized by transient apical dyskinesia in the presence of angiographically normal coronary arteries.¹ The release of cardiac markers tends to be limited and disproportionate to the extent of akinesia. Recently, atypical forms of TT cardiomyopathy, where other myocardial segments exhibit the characteristic transient wall motion abnormalities, have been reported.¹ Inverted and mid-ventricular TT cardiomyopathy represent atypical forms of the condition also associated with normal coronary arte ies. Although the etiology remains unknown, a catecholamine excess appears to play a key pathophysiologic role and differences in cardiac adrenergic receptor location might explain the variant forms.¹ In these, sparing of apical segments further supports a non-coronary etiology. However, angiography is unable to visualize the underlying coronary vessel wall. Therefore, intracoronary diagnostic techniques may prove useful to definitively rule out angiographically silent coronary artery disease in these patients.^2-4 In this report, we describe for the first time the optical coherence tomography (OCT) findings in a patient with atypical TT cardiomyopathy presenting as transient mid-ventricular ballooning.

Case Report. A 55-year-old woman with a previous history of hypertension and hyperlipidemia was admitted for prolonged chest pain and an acute anxiety crisis after an episode of work-related distress. On admission, the electrocardiogram showed negative T-waves on I and aVL and widespread repolarization abnormalities. An echocardiogram revealed severe left ventricular dysfunction with akinesia of the anterolateral and inferior walls. Coronary angiography showed normal coronary arteries with very well developed left anterior descending (LAD) and left circumflex (LCX) coronary arteries. A left ventricular angiogram disclosed a unique systolic pattern (hawk’s beak morphology) with severe akinesia of the anterolateral and diaphragmatic walls, but with hypercontractility at the basal and apical left ventricular segments (Figure 1). Mitral regurgitation was absent and no intraventricular gradient could be elicited. Frequency domain OCT (Dragon Fly, C7-XR; Light Lab, St Jude Medical) with a non-occlusive technique was performed on the LAD (2 overlapping 50 mm runs, adequate image length of 75 mm) and on the LCX (2 overlapping 50 mm runs, adequate image length of 65 mm). The coronary wall was normal at all segments, showing a typical three-layered appearance (Figure 2). The thickness of the vessel wall ranged from 180-320 μm and from 200-270 μm at the LAD and LCX, respectively. Specifically, no significant atherosclerotic plaques could be visualized at any site, and no images of residual intracoronary thrombus, plaque ruptures, or thin-cap fibroatheromas were detected (Figure 2). The patient had a favorable clinical course, with normalization of the repolarization changes and progressive recovery of wall motion abnormalities. The troponin I peak was only 1.43 ng/mL. At discharge, an echocardiogram confirmed complete disappearance of all left ventricular wall motion abnormalities and a normal systolic function.

Discussion. OCT is of great value in disclosing the underlying pathological substrate in patients with acute myocardial infarction.^5,6 In these patients, intracoronary thrombus, either emerging from a rupture of a thin-cap fibroatheroma or plaque erosion, is systematically detected with OCT.^5,6 Some of these patients, however, may eventually evolve, with thrombus resolution leading to mild residual stenosis or even to completely normal coronary vessels on angiography. In this setting, OCT is able to unravel the underlying culprit plaque and also residual intraluminal thrombi, thus confirming the diagnosis of atherosclerotic coronary artery disease. Notably, in our patient coronary artery disease was ruled out by OCT.

Our findings demonstrate that atypical mid-ventricular TT cardiomyopathy may occur in patients with structurally normal epicardial coronary vessels. In this case, OCT was able to rule out the presence of any subtle pathologic change at the vessel wall. The unprecedented, near histological, resolution of OCT (15 μm) provides reassuring evidence in this regard. This is of interest because in some patients with TT cardiomyopathy, intravascular ultrasound (resolution, 150 μm) has been able to un- ravel silent atherosclerosis.² Furthermore, in some of these patients, intravascular ultrasound has demonstrated angiographically silent ruptured atherosclerotic plaques.³ However, a recent OCT report on a more classic form of TT cardiomyopathy (apical ballooning) demonstrated completely normal epicardial coronary vessels.⁴ In this regard, the current report provides complementary information from a patient presenting with transient mid-ventricular ballooning.

Conclusion. Our findings strongly suggest that the different phenotypic variants of this reversible cardiomyopathy may indeed occur in patients with completely normal coronary vessels at a micro-structural level. OCT provides unique insights in this setting. Further studies are warranted to unravel alternative etiologies in patients presenting with this elusive and challenging clinical entity.

References

1. Hurst RT, Askew JW, Reuss CS, et al. Transient midventricular ballooning syndrome. A new variant. J Am Coll Cardiol. 2006;48(3):579-583.
2. Haghi D, Hamm K, Heggemann F, et al. Coincidence of coronary artery disease and Tako-Tsubo cardiomyopathy. Herz. 2010;35(4):252-256.
3. Ibañez B, Navarro F, Cordoba M, M-Alberca P, Farre J. Tako-Tsubo transient left ventricular apical ballooning: is intravascular ultrasound the key to resolve the enigma? Heart. 2005;91(1):102-104.
4. Alfonso F, Núñez-Gil IJ, Hernández R. Optical coherence tomography findings in Tako-Tsubo cardiomyopathy. Circulation. 2012;126(13):1663-1664.
5. Kubo T, Imanishi T, Takarada S, et al. Assessment of culprit lesion morphology in acute myocardial infarction: ability of optical coherence tomography compared with intravascular ultrasound and coronary angioscopy. J Am Coll Cardiol. 2007;50(10):933-939.
6. Prati F, Uemura S, Souteyrand G, et al. OCT-based diagnosis and management of STEMI associated with intact fibrous cap. JACC Cardiovasc Imaging. 2013;6(3):283-287.

From Interventional Cardiology, Cardiovascular Institute, Clínico San Carlos University Hospital, Madrid, Spain.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript submitted May 7, 2013, provisional acceptance given May 28, 2013, final version accepted June 10, 2013.

Address for correspondence: Fernando Alfonso MD, Cardiac Department, Hospital Universitario de la Princesa, IIS-IP, Universidad Autónoma, Madrid 28006, Spain. Email: falf@hotmail.com