Persistent Symptoms and Early Incomplete Recovery After Acute Stress-induced Cardiomyopathy: Is There Ongoing Heart Distress? The HEROIC Study

Overview

Acute stress induced (Tako-tsubo) cardiomyopathy (TTC) or broken heart syndrome, a condition typically occurring after acute stress has a death rate similar to heart attacks and is frequently associated with long-term symptoms (fatigue and exercise limitation). There are no effective therapies. The investigators have recently showed that there is a profound shortage of energy in the hearts of Tako Tsubo Cardiomyopathy patients in the days after acute presentation with only partial recovery by four months. The investigators would now like to establish whether this recovers after at least one year, or persists, and also to investigate the mechanisms responsible for exercise limitation after recovery from the acute phase.

Tako Tsubo Cardiomyopathy presents with sudden onset of chest pain that mimics a myocardial infarction (MI) and is precipitated by major emotional/physical stress. Classically, the coronary arteries are normal and yet, the left ventricular (LV) angiogram shows a characteristic, extensive and severe wall motion abnormality, some develop cardiogenic shock, cardiac rupture or embolic stroke. In the weeks following onset, the wall motion abnormalities gradually recover: this led to the assumption that Tako Tsubo Cardiomyopathy is self-limiting, reinforced by the absence of myocardial damage on cardiac Magnetic Resonance Imaging. However, the investigators and others have shown that Tako Tsubo Cardiomyopathy recovery is not rapid, being characterised by severe global oedema, which persists for 3-4 months after presentation. The investigators showed profound decrease in cardiac energetics during the acute Tako Tsubo Cardiomyopathy phase compared to healthy controls. This improved significantly at follow up but remained reduced compared to healthy controls. These objective findings of incompletely resolved myocardial oedema and energetic impairment are in contrast with the more rapid apparent recovery of Left Ventricular Ejection Fraction but are in keeping with the persistence of symptoms previously reported in literature and with the investigators' own clinical observations from the Tako Tsubo Cardiomyopathy follow-up clinic at the institution. The persistence of symptoms (fatigue, recurrent chest pains, decreased exercise capacity) could be due to either: 1. Subclinical degree of impairment in cardiac energetics/function (reflecting either an even more prolonged status of incomplete recovery or a pre-existent cardiomyopathy) which despite a normalised for almost normalised ejection fraction at rest results in cardiac limitation during exercise, or 2. Physical deconditioning after an acute, severe illness.