Lesser Severity of Recurrent Takotsubo Cardiomyopathy While Taking Angiotensin II Receptor Blocker and Beta Blocker

Abstract

Case report summary Takotsubo cardiomyopathy (TC) is a rare syndrome following acute stress. Recurrence occurs in 2%- 12% of patients yearly. We present a case of recurrent TC treated with an angiotensin receptor blocker (ARB) and beta blocker (BB). Repeat episode showed less severe cardiac enzyme elevation, echocardiogram and hospital course. We hypothesise her medication regimen contributed to a milder manifestation. Background TC is characterised by transient systolic and diastolic dysfunction, left ventricular wall motion abnormalities and troponin I (Tnl) elevations with normal coronary arteries. No consesus exists for medical treatment. Case presentation A 59 year old female presented with severe chest pain lasting 12 hours. ECG showed ST-depressions. Labs were significant for elevated TnI of 13 ng/ml and BNP >600 ng/ml. Transthoracic echocardiogram (TTE) demonstrated left ventricular ejection fraction of 35% and hypokinesis consistent with TC. Catheterization showed no obstruction. She was discharged on losartan and carvedilol. 4 months later she experienced similar chest pain. Lab tests revealed mildly elevated TnI (0.7 ng/ml) and a normal BNP. ECG, TTE and catheterization were unremarkable. She was seen at our clinic 1 month later for cardiology consultation. Daily medications included carvedilol, losartan, isosorbide mononitrate, aspirin, and nitroglycerin. The ARB was discontinued and an angiotensin-converting-enzyme inhibitor (ACEi) was started. She has now been symptom free for 6 months. Discussion Several hypotheses exist regarding pathogenesis. Excessive epinephrine after beta-adrenergic response may result in a decline of cardiac myocyte activity. Catecholamines impact endothelial function resulting in myocyte toxicity. These theories are supported by the relationship between TC and oestrogen withdrawal as patients lose protection from catecholamine toxicity, calcium overload and oxidative stress. BBs have been explored as potential treatment. To date, no improvement in recurrence or mortality has been established although a large multi-centre study found improved survival rates 1 year after TC event with ACEi/ ARB treatment.