The clinical characteristics, laboratory parameters, electrocardiographic, and echocardiographic findings of reverse or inverted takotsubo cardiomyopathy: Comparison with mid or apical variant

Background: Although takotsubo cardiomyopathy (TTC) typically affects the apical and/or midventricular segments, several recent cases have reported a reverse or inverted variant of TTC. The aim of this study was to investigate the clinical characteristics, laboratory parameters, electrocardiographic, and echocardiographic findings in patients presenting as inverted TTC and compare those parameters to those presenting as mid or apical variant. Hypothesis: The clinical features of inverted TTC are different from those of other types of TTC. Methods: Of 103 patients enrolled from the TTC registry database, 20 showed inverted TTC (inverted TTC group), and 83 showed mid or apical variant (other TTC group). Results: Clinical presentations and in-hospital courses were mostly similar between the groups. However, the inverted TTC group was younger (median, 54.5 vs 64.0 years; P = 0.006) than other TTC and had a higher prevalence of triggering stress (100% vs 77%, P = 0.018), whereas other TTC group had higher prevalence of dyspnea (58% vs 30%, P = 0.025), pulmonary edema (46% vs 20%, P = 0.035), cardiogenic shock (36% vs 10%, P = 0.023), T-wave inversion (81% vs 60%, P = 0.049), and significant reversible mitral regurgitation (MR) (19% vs 0%, P = 0.033). Also, the inverted TTC group had significantly higher creatine kinase MB fraction (CK-MB); CK-MB (median, 30.7 vs 7.6 ng/mL; P = 0.001) and troponin-I (median, 13.1 vs 1.6 ng/mL; P = 0.001), but lower N-terminalpro-brain natriuretic peptide (NT-proBNP) levels (median, 613.3 vs 4987.0 pg/mL; P = 0.020). Conclusions: Inverted TTC presents at a younger age and has a higher prevalence of triggering stress, whereas other TTC has a higher prevalence of heart failure symptoms, significant reversible MR, and T-wave inversion and higher NT-proBNP levels despite other clinical features that are mostly similar.