Differences in the Clinical Profile and Outcomes of Typical and Atypical Takotsubo Syndrome: Data From the International Takotsubo Registry.

IMPORTANCE: Apical ballooning is broadly recognized as the classic form of takotsubo syndrome (TTS). Atypical subtypes of TTS also exist, which constitute about 20% of all cases. To date, clinical profile and course of atypical TTS types have rarely been studied.

OBJECTIVE: To characterize the clinical profile and outcomes of typical vs atypical types of TTS in a large patient cohort.

DESIGN, SETTING, AND PARTICIPANTS: Records of 1750 patients from the International Takotsubo Registry, comprising 26 participating cardiovascular centers in 9 different countries, were reviewed and data on clinical profile and outcomes collected from January 1, 2011, to December 31, 2014.

MAIN OUTCOMES AND MEASURES: Clinical characteristics and in-hospital as well as long-term outcomes were assessed.

RESULTS: Of 1750 patients diagnosed with TTS between 1998 and 2014, a total of 1430 (81.7%) presented with apical TTS (defined as typical TTS) and 320 (18.3%) with midventricular, basal, or focal TTS (all defined as atypical TTS). Patients with atypical TTS were younger than those with typical TTS (mean [SD], 62.5 [13.3] vs 67.3 [12.9] years; P < .001). Brain natriuretic peptide levels on admission were lower (median factor increase of the upper limit of normal, 4.18 vs 6.59; P = .02) and left ventricular ejection fraction was higher (mean [SD], 43.4% [10.7%] vs 40.6% [12.0%]; P < .001) in patients with atypical than those with typical forms of TTS. ST-segment depression was more prevalent in patients with atypical TTS (31 of 286 [10.8%] vs 90 of 1292 [7.0%]; P = .03), while ST-segment elevation was found more frequently in patients with typical TTS (593 of 1292 [45.9%] vs 97 of 286 [33.9%]; P < .001). Patients with atypical TTS more often had neurologic disorders than those with typical TTS (81 of 274 [29.6%] vs 286 of 1251 [22.9%]; P = .02). While in-hospital mortality was comparable between patients with atypical and typical TTS (10 of 320 [3.1%] vs 62 of 1430 [4.3%]; P = .32), the atypical forms showed a favorable outcome at 1 year (P = .01). However, after adjustment for confounders, only left ventricular ejection fraction less than 45%, atrial fibrillation, and neurologic disease, but not the type of TTS, were independent predictors. After 1 year, patients with both types of TTS showed a similar prognosis at long-term follow-up.

CONCLUSIONS AND RELEVANCE: Atypical TTS has different characteristics than typical TTS, including younger age of onset, more frequent ST-segment depression, higher prevalence of neurologic diseases, less pronounced reduction in left ventricular ejection fraction, and lower brain natriuretic peptide values on admission. Outcomes are comparable between patients with both types after adjustment for confounders, suggesting that both should be equally monitored.