Cardiac troponin elevation and mortality in takotsubo syndrome: new insights from the International Takotsubo (InterTAK) registry

Background/Introduction

Cardiac biomarker elevations are frequently observed in Takotsubo syndrome (TTS). The clinical relevance of cardiac troponin (cTn) elevations in TTS patients remains uncertain and threshold values indicating clinically relevant myocardial injury are unknown.

Purpose

This study sought to investigate the role of cTn elevations in mortality prediction of patients with TTS.

Methods

A total of 2,938 patients enrolled in the prospective International Takotsubo (InterTAK) Registry from January 2011 to February 2020 and with available data on baseline and peak cTn levels were included in the analysis. The threshold at which myocardial injury drives mortality was identified using restricted cubic spline analysis.

Results

Out of 2,938 patients, 222 (7.6%) patients died during 1-year follow-up. A more than 28.8-fold increase of cTn above the upper reference limit was identified as threshold for clinically relevant myocardial injury. Mortality at 1 year was significantly higher in patients with clinically relevant myocardial injury than in those without (Log Rank p<0.001, Figure 1). The presence of clinically relevant myocardial injury was significantly associated with an increased risk of mortality at 5 years (adjusted HR 1.58, 95% CI 1.18–2.12, p=0.002). Clinically relevant myocardial injury was related to 5-year mortality in patients with apical TTS (adjusted HR 1.57, 95% CI 1.21–2.03, p=0.001), with presence of physical stressors (adjusted HR 1.60, 95% CI 1.22–2.11, p=0.001), and with absence of emotional stressors (adjusted HR 1.49, 95% CI, 1.17–1.89, p=0.001).

Conclusions

This study for the first time determined a troponin threshold for the identification of TTS patients at excess risk of mortality. These findings advance risk stratification in TTS and assist in identifying patients in need for close monitoring and follow-up.

Funding Acknowledgement

Type of funding sources: Foundation.

Body weight and mortality in takotsubo syndrome: insights from the International Takotsubo (InterTAK) registry

Background/Introduction

The obesity paradox has been described in different cardiovascular conditions. Data on the association between obesity and outcomes in patients with Takotsubo syndrome (TTS) are lacking.

Purpose

The aim of this study was to determine the relation of body weight to mortality in TTS patients.

Methods

Patients enrolled in the International Takotsubo (InterTAK) Registry from January 2011 to July 2021 and with available data on BMI were included in the analysis. Patients were stratified according to BMI (underweight, <18.5 kg/m2; normal weight, 18.5–24.9 kg/m2; overweight, 25.0–29.9 kg/m2; obese, 30.0–34.9 kg/m2; and very obese, ≥35.0 kg/m2). The primary endpoint was mortality at 1 year.

Results

Of the 2'707 patients, 222 (8.2%) were underweight, 1340 (49.5%) of normal weight, 759 (28.0%) overweight, 268 (9.9%) obese, and 118 (4.4%) very obese. Mortality at 1 year as a function of BMI with 95% confidence interval is given in Figure 1. Mortality at 1 year was 11.3%, 6.9%, 5.5%, 4.9%, and 9.3% in underweight, normal weight, overweight, obese, and very obese patients (p=0.02, Figure 2). Being overweight or obese was significantly associated with a lower mortality at 1 year (HR 0.70, 95% CI 0.51–0.96, p=0.03), and associations remained significant after multivariable adjustments (adjusted HR 0.67, 95% CI 0.46–0.97, p=0.03). Associations were observed when including patients without emotional stressors (adjusted HR 0.64, 95% CI 0.43–0.94, p=0.02), but not when including those with emotional stressors (adjusted HR 1.14, 95% CI 0.30–4.27, p=0.85).

Conclusion

A U-shaped mortality curve across BMI categories was observed in TTS patients, with lowest mortality rates in obese patients. These observations provide first evidence for the existence of the obesity paradox in TTS.

Funding Acknowledgement

Type of funding sources: Foundation.

P810Novel scoring system for takotsubo syndrome

Background

Scoring systems for risk stratification in takotsubo syndrome (TTS) are lacking.

Purpose

The present study aimed to develop a score to predict the overall mortality in TTS.

Methods

TTS patient were enrolled from a multicenter registry. Parameters known to be associated with adverse outcomes in TTS were identified based on current literature. A multivariable analysis including these parameters was conducted and those which were found to be significantly associated with mortality were considered in the scoring system. For each patient, the prognostic score was derived by summing the respective points of each prognostic factor. Based on cut-off values, patients were categorized into four groups including low, intermediate, high, and very high risk.

Results

A total of 1160 patients (90.8% females; mean age 66.5±13.0 years) were included in the present study. Regarding triggering factors, an emotional trigger was identified in 32.6% of TTS patients while 32.1% had preceding physical activities, medical conditions, or procedures and 5.7% had preceding neurologic disorders. The remaining patients (29.7%) had no identifiable triggering factors. According to the results from multivariable analysis, points were assigned to each parameter that was independently associated with long-term mortality: 15 points for neurologic trigger, 10 points for the other physical trigger, 8 points for Age >70 years, 7 points for male sex, 7 points for left ventricular ejection fraction ≤45%, 6 points for diabetes mellitus, 5 points for heart rate >94 bpm on admission, 5 points for systolic blood pressure >140 mmHg on admission, and 2 points for no identifiable trigger. Based on the total points, patients were categorized into four prognostic groups: low-risk ≤15 points (43.5%), intermediate-risk 16–22 points (28.0%), high-risk 23–29 points (18.0%), and very high-risk >29 points (10.5%).

Conclusion

This novel score for risk stratification in TTS only requires easy-obtainable variables to clinicians even in the acute phase and could identify low to very high risk of overall mortality. Thus, it could potentially serve as a useful clinical tool to predict prognosis in patients with TTS.