Comparison and outcome analysis of patients with apical and non-apical takotsubo cardiomyopathy

Background: Takotsubo cardiomyopathy (TTC) is a relevant differential diagnosis in patients presenting with signs of an acute coronary syndrome. Although recent literature has highlighted some salient features of this disorder, there has been little information elucidating the differences in clinical features, electrocardiographic findings, echocardiographic data and TTC-related complications associated with the different variants of TTC. Methods and results: Our institutional database constituted a collective of 114 patients diagnosed with TTC between 2003 and 2015 and these patients were subsequently divided into two groups based on the presence (n = 82, 72%) or absence (n = 32, 28%) of the apical form of TTC. The protocol for our proposed study was approved by the Ethics Committee of the University Medical Centre in Mannheim. It was noticed that the patients presenting with the apical form of TTC belonged to an older age group as compared to those presenting with the non-apical form (61.1 +/- 8.9 years vs. 69.5 +/- 11.2; P < 0.01). The QTc interval prolongation at index-event was observed to be quantifiably greater in the 'apical variant' patients group (484.8 +/- 57ms vs. 464 +/- 34.1 ms; P=0.06). With respect to cardiovascular risk factors, patients with arterial hypertension did have a higher predilection to present with the apical form (63.4% vs. 43.7%; P = 0.06), however, the impact of smoking was less pronounced in this patient group (24.4% vs. 50%, P = 0.01). Furthermore, our study highlighted a significant impact on ejection fraction (EF), with a compromised left ventricular function (3669% vs. 42.469.7%, P < 0.01) and greater involvement of the right ventricle in the apical variant patients group (23% vs. 3%, P = 0.04). Patients with the apical form also showed a greater tendency to develop TTC-related complications such as cardiogenic shock and required longer monitoring and care in comparison. Conclusions: The apical and non-apical variants of TTC are manifestations of the same syndrome. They differ significantly, however, in their clinical presentation, related complications and prognosis.