Impact of Brain Natriuretic Peptide, Calcium Channel Blockers, and Body Mass Index on Recovery Time from Left Ventricular Systolic Dysfunction in Patients With Takotsubo Cardiomyopathy

Takotsubo cardiomyopathy (TC) is generally recognized to have a good prognosis, but it can be rarely aggravated. We sought to investigate the clinical characteristics of TC and to evaluate the effects of clinical parameters on predicting delayed recovery. We enrolled consecutive patients with TC admitted to our hospital from January 1991 to January 2014. We defined delayed recovery as sustained left ventricular (LV) systolic dysfunction requiring ≥10 days for LV contraction to normalize. We screened 9,630 patients suspected of having acute coronary syndrome, and 60 patients (0.6%; men/women: 20/38; mean age: 69.7 ± 11.9 years) were diagnosed as having TC. With the exception of 2 patients who died before LV systolic function improved, all patients recovered from LV systolic dysfunction within 6 months; the mean recovery period was 9.1 ± 11.5 days. Twenty-eight patients met the criteria for delayed recovery. Univariate logistic regression analyses showed that male gender, LV end-diastolic diameter, brain natriuretic peptide (BNP) level, body mass index (BMI), and nonuse of calcium channel blockers (CCBs) at baseline were associated with delayed recovery. Among these factors, multiple logistic regression analysis identified BNP ≥238 pg/ml (relative risk [RR] 11.6, p = 0.002) and nonuse of CCBs (RR 22.2, p = 0.0014) as independent risk factors for delayed recovery and leptosomic build (BMI <20 kg/m2) as an independent predictor of rapid recovery (RR 0.11, p = 0.02). In conclusion, BNP level, BMI, and use of CCBs are associated with recovery speed of LV systolic function in patients with TC.