The Arduous Task of Differentiating Takotsubo Syndrome from Myocardial Infarction With Normal Coronary Arteries

I read the study by Daniel et al, published online ahead of print on June 25, 2015, in the AJC , about a series of 100 patients with a myocardial infarction with angiographically normal coronary arteries (MINCA), 25 of whom had been diagnosed as having takotsubo syndrome (TTS), as per the Mayo Clinic criteria. The investigators have focused on the risk factors and markers of the patients with MINCA, a cohort of 100 patients with myocardial infarction and coronary heart disease, and 100 subjects considered as normal controls. I have some comments and inquiries for the kind consideration of the investigators: (1) A subgroup of 19 patients with possible TTS has been included in keeping with a previous speculation that such cases of atypical or milder cases of TTS may exist, and one wonders as to the most plausible diagnosis in the remaining 56 patients. (2) There have been cases of patients with TTS who showed rapid restoration of the left ventricular function within hours after presentation, and one wonders whether some, or all, of these 56 patients with MINCA had presented to the hospital later, after the inception of the illness, than the 25 patients with “typical” TTS or the sum of the 44 patients with “typical” and “atypical” TTS. (3) Regarding the 17 or 11 clinically excluded and/or cardiac magnetic resonance imaging–based diagnosed patients with myocarditis, one wonders whether some had solely TTS or myocarditis with TTS as a co-morbidity, considering the diagnostic fuzziness in distinguishing these 2 clinical syndromes, a concept previously proposed by one of the authors of the present report. (4) Only 1 of the 25 patients with TTS (prevalence of 4%) had diabetes mellitus (DM), in keeping with a recent report associating TTS with a low prevalence of DM. This prevalence of DM in patients with TTS is lower than expected for a population of mainly women of ∼60 years old of the general population. The issue here is complicated by the report of a 35% prevalence of combined impaired glucose intolerance and DM, in the TTS cohort of 25 patients (Table 2 of the present report), which is not a commonly reported variable in the TTS literature. The low prevalence of DM (4%) of patients with TTS was also noted (with the same 4%) in the 56 patients with MINCA but “no TTS” (Table 2), some or all of whom might also have had TTS. The prevalence of DM in patients with TTS needs to be evaluated in large cohorts with detailed reference to the type of DM (type 1 or 2), antidiabetic therapy used, and the presence of diabetic neuropathy (including autonomic neuropathy) because it may have pathogenetic implications (protective effect) for the emergence of TTS.

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Nov 28, 2016 | Posted by in CARDIOLOGY | Comments Off on The Arduous Task of Differentiating Takotsubo Syndrome from Myocardial Infarction With Normal Coronary Arteries

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