By Michael H. Crawford, MD, Editor

SYNOPSIS: Investigators sought to determine whether secondary prevention interventions could reduce the mortality rate of takotsubo patients with cardiac arrest.

SOURCES: Gili S, et al. Cardiac arrest in takotsubo syndrome: Results from the InterTak Registry. Eur Heart J 2019;40:2142-2151.

Wittstein IS. Cardiac arrest and takotsubo syndrome. Eur Heart J 2019;40:2152-2154.

Although usually benign, takotsubo syndrome (TS) can cause life-threatening complications, but little is known about the frequency and outcomes of cardiac arrest (CA) in TS.

Researchers from the International Takotsubo (InterTAK) Registry interrogated this multicenter, prospective registry of TS patients from 2011 through 2017 for patients with CA and known underlying rhythm. Of the 2,098 patients available at the time, 124 met the inclusion criteria. Baseline characteristics showed that CA patients were younger and more often men compared to the rest of the patients. On admission, study subjects presented with lower left ventricular ejection fraction and more often were in atrial fibrillation (21% vs. 6%; P < 0.001). CA was the presentation of TS in 82%, and 18% developed CA during the acute phase of TS. In the CA at presentation group, 57% had ventricular fibrillation or tachycardia (VF/VT), while 74% of those who developed CA in the acute phase exhibited asystole or pulseless electrical activity (PEA). Patients with CA died more often at 60 days (40% vs. 4%; P < 0.001) and five years (69% vs. 17%; P < 0.001). The multivariate adjusted predictors of 60-day mortality were T wave inversion on ECG, intracranial hemorrhage, and male sex.

The authors concluded that CA was not uncommon in TS, is associated with higher short- and long-term mortality, and can be predicted by clinical and ECG parameters.

COMMENTARY

Today, TS is recognized more often since we are treating more patients with suspected acute coronary syndrome for left heart catheterization. Also, the characteristic regional wall motion patterns are becoming more familiar on echocardiography. Although generally considered a low-risk condition because the wall motion abnormalities usually are reversible, in-hospital mortality is similar to acute myocardial infarction.

This investigation, based on the InterTAK Registry, showed that CA occurred in 6% of TS patients, and CA that occurred in hospital carried a mortality rate of 35%. T wave inversion on ECG and the presence of intracranial hemorrhage were independent predictors of mortality. Indeed, CA was more common in TS patients with physical triggers rather than emotional ones.

Since mortality occurred more often in those with physical conditions triggering TS, this may be due to the underlying disease or other comorbidities in these patients. However, late mortality was six-fold higher in post-CA patients compared to TS patients without CA. It is difficult to understand how physical conditions would increase five-year mortality so markedly. This raises the question of whether TS patients who go into CA should go home with a defibrillator vest or receive an implantable cardioverter defibrillator (ICD).

About 80% of CA patients experienced their arrest at presentation and usually were in VF/VT. In the one-fifth who developed CA after admission for TS, it usually was because of PEA or asystole, which suggests they presented with severe myocardial dysfunction. Consequently, the latter patients may not benefit from an ICD. Since the median time to CA was one day, TS patients should be monitored (at a minimum) for 48-72 hours.

What to do after that is unclear, as initial anecdotal experience with ICDs has been disappointing. Further research will be required to determine the best secondary prevention technique for these challenging patients with TS and CA.