Background:
Transient Stress Cardiomyopathy (TSC) is a reversible condition mimicking acute myocardial infarction that frequently affects postmenopausal women and is often triggered by emotional or physical stress. Limited information is available about the long-term prognosis of this condition as previous studies were mostly case series and/or were unable to adjust for several confounding variables. The aim of this retrospective cohort study was to assess the post-hospital discharge prognosis of women diagnosed with TSC compared with historical ST-elevation myocardial infarction (STEMI) female controls. The principal study outcome was a composite of cardiovascular (CV) hospital readmissions and death from any cause.
Methods:
Cases were identified by reviewing the charts of consecutive women hospitalized at UMass Memorial Medical Center in Worcester, MA, with an ICD-9 code of 429.83 (Takotsubo cardiomyopathy) from 01/2002 until 06/2012. To be eligible, cases had to fulfill all Mayo clinic criteria for TSC. Controls were randomly selected (2:1 ratio) among women with a validated diagnosis of STEMI enrolled in the Worcester Heart Attack Study during the same period. Clinical characteristics and information about CV readmissions and death were abstracted from the medical record. Survival curves were generated by the Kaplan-Meier method. Log-rank statistics was used to compare survival curves. Risk of death or CV readmissions (with the STEMI category as the referent) was estimated from multivariate Cox proportional hazard regression models adjusted for variables associated with the composite outcome.
Results:
Out of 356 consecutive women hospitalized with an ICD-9 code of 429.83 (Takotsubo cardiomyopathy), 50 met Mayo diagnostic criteria. Baseline age was 65±14 years in TSC cases and 71 ±15 in STEMI controls (n=100). The prevalence of coronary risk factors, and of a history of angina, stroke and heart failure, was lower among TSC cases vs. controls. At admission, TSC women had lower peak CK, troponin I levels and SBP values; mean (angiogram) ejection fraction was 0.32 in TSC and 0.47 in STEMI women. TSC cases were less frequently prescribed aspirin, beta-blockers, lipid lowering agents and ACE inhibitors at hospital discharge. Over an overall average follow-up of 2 years, incidence rates of the composite outcome were 140/1,000 person-years among women with TSC and 347/1,000 person-years among those with STEMI. In multivariate adjusted models, the hazard ratio for the composite endpoint in TSC vs. STEMI women was 0.50 (CI: 0.26,0.98).
Conclusion:
Women diagnosed with TSC had a significantly better post-discharge prognosis than women with STEMI. However, mortality and CV readmissions rates among TSC women were relatively high, indicating that TSC is not a benign condition.
Pathogenesis of Ventricular Arrhythmias and Its Effect on Long-Term Prognosis in Patients With Takotsubo Cardiomyopathy