Frequency and significance of myocardial bridging and recurrent segment of the left anterior descending coronary artery in patients with takotsubo cardiomyopathy

Despite intensive research efforts, the causative mechanisms of takotsubo cardiomyopathy (TC) are still unknown. Recently, morphologic characteristics of the left anterior descending coronary artery (LAD) have been proposed as a potential pathophysiological substrate. Hence, the aim of the present study was to evaluate the prevalence of myocardial bridging and LAD recurrent segments in a large cohort of patients with TC. A total of 161 patients with TC were matched for age and gender with 161 controls without coronary artery or valvular heart disease. Myocardial bridging was diagnosed according to indirect signs in coronary angiography. Furthermore, the LAD was evaluated regarding parts of the vessel outreaching the left ventricular apex (LAD recurrent segment). The prevalence of myocardial bridging was similar in the TC and control groups (11.8% vs 6.8%, p = 0.18). Any part of the LAD outreaching the left ventricular apex was observed in 55.6% of patients with TC compared with 35.4% in the control population (p <0.001). Moreover, the LAD supplied ≥25% of the inferior myocardial wall in 21 patients with TC (13.1%), whereas patients in the control group did not show this pattern of coronary circulation at all (p <0.001). Patients with TC with typical apical ballooning compared with those with atypical ballooning patterns demonstrated a higher prevalence of myocardial bridging (p = 0.04) but not LAD recurrent segments (p = 0.28). In conclusion, the prevalence of myocardial bridging in patients with TC is low and comparable with that in a matched control group. In contrast, LAD recurrent segments are significantly more frequent in patients with TC.