Comparison of clinical features and outcomes of Chinese patients with Takotsubo syndrome and acute myocardial infarction—results from the first Chinese Takotsubo syndrome registry

Introduction

Takotsubo syndrome (TTS) is characterized by a transient and reversible systolic dysfunction (1,2). It was initially perceived as a relatively benign disease due to its transient reversibility (3). However, subsequent studies based on multiple international TTS registries have revealed that TTS is associated with acute in-hospital complications and an increased risk of mortality (4,5), and the prognosis of TTS and acute myocardial infarction (AMI) may be comparable (6-8). However, global data on TTS is uneven, particularly in Asia. In Japan, several studies have compared TTS and AMI patients, but they primarily focus on clinical characteristics and in-hospital mortality rates (9,10). More comprehensive data are needed to compare the prognoses of TTS and AMI patients. Notably, the inaugural Chinese registry of TTS (ChiTTS Registry) has revealed that Chinese TTS patients exhibit a higher incidence of in-hospital complications and short-term major adverse cardiovascular and cerebrovascular events (MACCEs) when compared to European and United States TTS patients (4,11). Therefore, we have performed a systematic analysis to compare the clinical features, complications, and prognosis of TTS and AMI in the Chinese population, based on data from the ChiTTS Registry. We present this article in accordance with the STROBE reporting checklist (available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-8/rc).

Methods

Study design and patient population

ChiTTS is a registry comprising 10 tertiary medical centers located in southern, eastern, and northern China (registration No. ChiCTR1900026725). All centers have experienced critical care teams and essential resuscitation facilities, including extracorporeal membrane oxygenation (ECMO) and intra-aortic balloon pump (IABP), etc. This observational study commenced on February 1, 2016, with the consecutive recruitment of TTS patients. As of June 4, 2022, a total of 116 patients had been enrolled. In accordance with previous studies, all TTS patients were met the international Takotsubo diagnostic criteria (4,11). During the same study period, patients diagnosed with AMI (ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction) were initially enrolled according to the diagnostic criteria used by participating medical centers at that time. For the current analysis, we included only 7,577 patients who also met the 2023 European Society of Cardiology guidelines for acute coronary syndromes diagnostic criteria (12) following retrospective adjudication. This study aimed to compare clinical characteristics, complications, and outcomes between AMI and TTS patients. Using propensity-score matching with age and gender as covariates, we established matched cohorts in a 1:2 (AMI:TTS) ratio for comparative analysis. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Scientific Ethics Committee of Kiang Wu Hospital (approval No. 2019-007). Moreover, all research protocols were reviewed and approved by the Clinical Research Ethics Committee of each medical center and individual consent for this retrospective analysis was waived.

Data collection

The enrollment criteria and data collection protocol followed the methodology outlined in the previous study and were ultimately compiled into a standardized spreadsheet (11). In brief, the data set included baseline characteristics such as age, gender, symptoms, signs upon admission, cardiovascular risk factors, coexisting medical conditions, triggers, cardiac biomarkers, electrocardiogram and imaging examinations (echocardiography and left ventricular angiography) results, use of medications, hemodynamic support during hospitalization, and discharge medications. To ensure data quality, two independent researchers from the core medical team entered all data consistently.

Outcomes and definitions

In-hospital complications were described in the previous study (4), defined as the utilization of invasive or noninvasive ventilation, administration of catecholamines, cardiopulmonary resuscitation, development of cardiogenic shock (CS, characterized by reduced cardiac output, persistent low blood pressure, and inadequate tissue perfusion), or death from any cause. The primary endpoints were short-term (100-day) and long-term MACCEs, which is a composite endpoint that includes all-cause death, recurrence (TTS or AMI), and stroke/transient ischemic attack (TIA) for all patients (4). The Secondary endpoints included the individual components of MACCEs, with separate analyses conducted for each. Follow-up was carried out through outpatient visits, inpatient medical records or telephone calls. Researchers from the core medical team recorded all follow-up data in a standardized form to ensure consistency and accuracy. Two specially trained medical experts from the team assessed the events with precision.

Statistical analysis

Continuous variables were presented as mean ± standard deviation (SD) or median [interquartile range (IQR)], while categorical variables were expressed as frequency and percentage. For variables with ≤5% missing data, we used complete-case analysis (applied to most variables), while mean imputation addressed higher missingness in others. Baseline characteristics between the two groups were assessed using the Student’s t-test or Wilcoxon rank-sum test for continuous variables, and Chi-squared or Fisher’s exact test for categorical variables. In the propensity score matching, we employed an optimal matching algorithm designed for small samples. The matching variables were age and gender, with a caliper set at 0.2 and a matching ratio of 1:2. As a result, 116 TTS patients were successfully matched with 232 AMI controls. The cumulative incidence of MACCEs was estimated using Kaplan-Meier curves, and differences were assessed with the log-rank test. Landmark analysis was used to compare the clinical outcomes between TTS and AMI patients. Statistical analyses were performed in SPSS software (version 26.0, SPSS, Chicago, IL, USA) and R language (R version 4.3.1). A two-tailed P value <0.05 was considered as statistically significant for all analyses performed.

Results

Patient demographic data and manifestations

The age and gender distribution between the TTS (n=116) and AMI (n=232) patients were well matched (P>0.05). The prevalence of cardiovascular risk factors was lower in TTS patients than in AMI patients. It is noteworthy that the proportion of TTS patients who experienced physical triggers was as high as 61.7%. The specific triggers and associated percentages are presented in Figure S1. The most common clinical manifestation in both groups was chest pain, followed by dyspnea and nausea/vomiting. Compared with AMI patients, TTS patients had a lower incidence of chest pain (63.5% vs. 91.4%), but a higher proportion of dyspnea (43.5% vs. 22.0%), nausea/vomiting (25.4% vs. 16.4%), syncope (11.4% vs. 2.2%) and other atypical symptoms (all P<0.05).

The study revealed that TTS patients exhibited a higher heart rate than AMI patients [92.0 (IQR, 76.0–114.0) vs. 80.0 (IQR, 70.0–90.0) beats per minute, P<0.001] and lower systolic and diastolic blood pressure [122.0 (IQR, 105.0–140.0) vs. 130.0 (IQR, 116.5–145.0) mmHg, P=0.046; 73.0 (IQR, 62.0–89.0) vs. 80.0 (IQR, 69.3–91.0) mmHg, P=0.02]. Additionally, TTS patients were more likely to present with features of heart failure, including pulmonary rales (47.9% vs. 26.3%), lower limb edema (16.5% vs. 4.7%), and a higher level of N-terminal pro-brain natriuretic peptide (NT-pro-BNP) or brain natriuretic peptide (BNP) [11.5 (IQR, 3.5–38.1) vs. 1.9 (IQR, 0.7–5.2) pg/mL, factor increase in upper limit of the normal range (ULN)] (all P<0.001). Conversely, the troponin level was significantly higher in patients with AMI [39.0 (IQR, 9.2–147.4) vs. 105.2 (IQR, 14.1–379.3) ng/mL, factor increase in ULN, P<0.001]. Compared to AMI patients, TTS patients had a significantly higher incidence of ventricular tachycardia/ventricular fibrillation (18.0% vs. 2.6%, P<0.001). However, there were no significant discrepancies between the two groups in term of left bundle branch block, ST-segment elevation, atrial fibrillation, or T-wave inversion (Table 1).

Treatment

TTS patients were discharged with significantly lower rates of angiotensin-converting enzyme inhibitors (ACEIs)/angiotensin receptor blockers (ARBs)/angiotensin receptor-neprilysin inhibitor (ARNI) (25.0% vs. 54.3%), beta-blockers (37.1% vs. 78.4%), calcium channel blockers (10.3% vs. 27.2%), statins (37.1% vs. 98.7%), and antiplatelet drugs (34.5% vs. 100.0%) compared with the AMI patients (all P<0.001). However, the use of diuretics was more prevalent among TTS patients (55.2% vs. 44.0%, P=0.048). The proportion of using ECMO for hemodynamic support was significantly higher in TTS patients (6.9% vs. 0.4%, P<0.001), while the IABP was not significantly different between the two groups (6.0% vs. 3.0%, P=0.18) (Table 1).

Outcome

TTS patients have longer hospital stays than AMI patients. The incidence of in-hospital complications was approximately twice as high among TTS patients compared to AMI patients (42.2% vs. 20.7%, P<0.001). TTS patients exhibited a markedly elevated incidence of CS (17.5% vs. 8.6%, P=0.02) and a significantly greater requirement for invasive/noninvasive ventilation (34.5% vs. 2.6%, P<0.001).

The median follow-up time was 1.23 (IQR, 0.33–2.63) years in ChiTTS Registry patients and 2.35 (IQR, 1.68–3.68) years in AMI patients. In terms of short-term outcomes, the rates of 100-day MACCEs and 100-day all-cause mortality were higher in TTS patients compared to AMI patients (19.6% vs. 10.8%, P=0.03; 17.9% vs. 8.9%, P=0.02, respectively). In terms of long-term outcomes, the rate of MACCEs was 14.2% per patient per year in TTS patients and 10.1% per patient per year in AMI patients (P=0.16). TTS patients had a significantly higher rate of all-cause mortality (13.1% vs. 5.9% per patient-year, P=0.005) (Table 2).

Kaplan-Meier survival analysis demonstrated no significant difference in long-term MACCEs (P=0.65) and all-cause mortality (P=0.054) between TTS and AMI patients (Figure 1A,1B). However, the landmark analysis indicated that TTS patients had more 100-day MACCEs [hazard ratio (HR) 1.87; 95% confidence interval (CI): 1.03–3.37; log-rank test P=0.04] and 100-day all-cause mortality (HR 2.07; 95% CI: 1.10–3.91; log-rank test P=0.02) compared to AMI patients. Landmark analysis also showed that long-term MACCEs and long-term all-cause mortality beyond 100-days were similar in the two groups (HR 0.38; 95% CI: 0.13–1.09; log-rank test P=0.06 and HR 0.96; 95% CI: 0.31–2.98; log-rank test P=0.94, respectively) (Figure 2A,2B).

Figure 1 Kaplan-Meier survival estimates for comparing long-term outcome events between TTS and AMI patients. (A) Comparison of long-term MACCEs rates; (B) comparison of long-term all-cause mortality. AMI, acute myocardial infarction; MACCEs, major adverse cardiovascular and cerebrovascular events; TTS, Takotsubo syndrome.

Figure 2 Landmark analysis assessed 100-day and long-term outcome events between TTS and AMI patients. (A) 100-day vs. long-term MACCEs outcomes; (B) 100-day vs. long-term all-cause mortality outcomes. AMI, acute myocardial infarction; MACCEs, major adverse cardiovascular and cerebrovascular events; TTS, Takotsubo syndrome.

Discussion

We completed the first systematic comparison of gender- and age-matched Chinese patients with TTS and AMI, then found that Chinese TTS patients may have more clinical manifestations associated with acute decompensated heart failure. Also, Chinese TTS patients demonstrated a higher incidence of in-hospital complications, and a worse short-term outcome compared to those with AMI.

Evidence is accumulating that TTS patients may increasingly develop in-hospital complications, including the use of catecholamines, the need for invasive or noninvasive ventilation, CS, cardiopulmonary resuscitation, and death (2,4,7,8). Our findings further indicate that the incidence of in-hospital complications in Chinese TTS patients is higher than that in AMI patients, particularly with more invasive/noninvasive ventilation requirements and CS. This discrepancy may be attributed to more diffuse left ventricular (LV) systolic dysfunction in TTS, which has recently been recognized as a key prognostic predictor (13-15). A prospective multicenter study with a 4-year follow-up found that TTS patients with delayed recovery of LV function had a higher incidence of comorbidities and more severe inflammatory responses, which were linked to worse hospital outcomes and increased long-term mortality risk (16). Additionally, this may also be influenced by gender and age factors, as TTS patients in this study are younger and have a higher proportion of males compared to Western TTS cohorts (17,18). Recent studies, including our initial investigation on the ChiTTS Registry, have demonstrated that younger age, male sex and the presence of experienced physical triggers in TTS (4,11) are associated with an increased risk of a higher prevalence of inpatient comorbidities (17,19-21). From the ChiTTS registry, we also identified that a clinical triad of dyspnea, hypotension, and tachycardia is a warning manifestation for subsequent inpatient complications (11). The international multicenter registry study also confirmed that dyspnea is independently linked to in-hospital complications and worsening long-term prognosis (22). The decompensated heart failure (and CS) in TTS patients is linked to poor prognosis (23) and can result from various mechanisms, including pump failure, right ventricular involvement, dynamic LV outflow tract obstruction, and acute mitral regurgitation (24). Identifying primary clinical signs of heart failure and CS in the first instance is crucial for choosing effective preventive and treatment plans. Inpatient physicians need to remain vigilant for these red flags to identify the patients who have a high risk of developing in-hospital complications at the earliest possible stage and provide the most appropriate treatment, so as to prevent or reduce TTS-associated adverse cardiac events and poor outcomes.

A recent investigation has shown that TTS patients have a poor short-term prognosis, with a 60-day mortality rate of up to 11% (25). While studies have examined MACCEs events in TTS patients, research on the differences in MACCEs rates between TTS and AMI is still needed. Previous studies suggest that LV function improves within 4–8 weeks after TTS, but recent research indicates that certain cardiac and metabolic impairments may last over 3 months (15,26). Therefore, we chose 100 days as the time point for our landmark analyses to evaluate the prognostic implications of these persistent impairments. In our current study, the 100-day mortality rate of ChiTTS registered patients is as high as 17.3%. Of note, the present study shows that Chinese TTS patients had higher short-term (100-day) MACCEs and all-cause mortality rates than AMI patients. An interesting observation from our follow-up imaging of TTS patients associated with poor prognosis investigation is that nearly 15% of Chinese TTS patients with abnormal ventricular wall motion exhibited prolonged recovery times of more than one month, while 8% required more than three months to completely recover, which is also indicated in European TTS patients (16). Unsurprisingly, among some TTS patients whose LV ejection fraction had already returned to normal, the persistent myocardial edema still existed in cardiac magnetic resonance imaging studies (27,28). In our study, 61.7% of Chinese TTS patients were induced by physical triggers, including stroke, severe infections, malignant cancers, acute respiratory failure, and trauma (Figure S1), which may contribute to their poor prognosis (29). The nationwide REgistry on TAKOtsubo syndrome study revealed a significantly elevated 30-day and 1-year mortality rate in patients with TTS accompanied by CS in comparison to patients with TTS without CS (13.6% vs. 1.14%, 19% vs. 3.4%, respectively) (17). Indeed, Chinese TTS patients in the ChiTTS registry had a higher prevalence of CS (17.5%), which may contribute to the unfavorable outcome. Supporting this inference, the recently developed TTS risk scoring system identifies CS as the strongest independent predictor of poor prognosis (30).

Of note, from our and others’ clinical experience and observation, a higher TTS mortality may be directly caused by misdiagnosis and inappropriate treatment. A historical review indicates that half of the early decrease in coronary heart disease mortality in the United States was due to the advancement of evidence-based medical treatments (31). In the present era, the in-hospital mortality rate of AMI patients is markedly reduced to approximately 4% when percutaneous coronary intervention is initiated within 90 minutes of hospitalization (32). Therefore, the mortality rate associated with TTS may not exceed that observed in AMI patients who did not receive immediate reperfusion therapy. Rather, the lack of effective treatments for TTS in comparison with well-established therapeutic strategies for AMI contributes to this difference. Since the current management of TTS is still mainly based on empirical clinical observations and expertise, there is a lack of clear evidence-based treatment recommendations (33). Moreover, there is significant individual variation in clinical treatment options for TTS patients at discharge, which could have a substantial impact on their prognosis. As a result, future efforts should aim to enhance the accuracy of TTS diagnoses and conduct further research into personalized treatment strategies.

Meanwhile, our study again showed that long-term outcomes of TTS are comparable with those of AMI, which is consistent with the results in previous investigations in European and United States TTS patients (6,8,16,34,35). Since an essential proportion of TTS patients are left with persistent cardiovascular abnormalities, reduced quality of life, and chronic complications, effective long-term treatment and secondary prevention are also needed for TTS patients at follow-up (11,36,37). Since the poor phenotypic grouping of TTS patients prevents effective therapeutic strategies for long-term risk reduction (25), identifying more homogeneous TTS populations and developing personalized medication and treatment strategies will be another important research focus down the road.

The main limitations of this study are its retrospective design and potential selection bias. Additionally, the lack of a central imaging analysis laboratory to certify LV function and the presence of missing data for some variables limited the completeness of the analysis. Furthermore, we cannot completely rule out the possibility of residual or unmeasured confounding, which prevents us from inferring causality from the observed associations. The variability in clinical perceptions and diagnostic criteria among the participating centers may have contributed to our inability to confirm that all eligible TTS patients were included in the study. We will expand the ChiTTS registry by recruiting more TTS patients from cardiovascular centers in China and improve diagnosis through clinician education and advanced tools. This will help validate our findings and facilitate prospective studies to enhance the reliability and generalizability of our results.

Conclusions

In comparison to AMI patients, Chinese TTS patients developed more in-hospital complications and had a worse short-term prognosis.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the STROBE reporting checklist. Available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-8/rc

Data Sharing Statement: Available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-8/dss

Peer Review File: Available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-8/prf

Funding: This work was supported by Science and Technology Development Fund, Macau SAR (No. 0117/2019/A3) and The Guangdong-Hong Kong-Macao University Joint Laboratory of Interventional Medicine Foundation of Guangdong Province (No. 2023LSYS001).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://cdt.amegroups.com/article/view/10.21037/cdt-2025-8/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Scientific Ethics Committee of Kiang Wu Hospital (approval No. 2019-007). Moreover, all research protocols were reviewed and received approval from the Clinical Research Ethics Committee of each medical center and individual consent for this retrospective analysis was waived.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Singh T, Khan H, Gamble DT, et al. Takotsubo Syndrome: Pathophysiology, Emerging Concepts, and Clinical Implications. Circulation 2022;145:1002-19. [Crossref] [PubMed]
2. Lyon AR, Citro R, Schneider B, et al. Pathophysiology of Takotsubo Syndrome: JACC State-of-the-Art Review. J Am Coll Cardiol 2021;77:902-21. [Crossref] [PubMed]
3. Lyon AR, Bossone E, Schneider B, et al. Current state of knowledge on Takotsubo syndrome: a Position Statement from the Taskforce on Takotsubo Syndrome of the Heart Failure Association of the European Society of Cardiology. Eur J Heart Fail 2016;18:8-27. [Crossref] [PubMed]
4. Templin C, Ghadri JR, Diekmann J, et al. Clinical Features and Outcomes of Takotsubo (Stress) Cardiomyopathy. N Engl J Med 2015;373:929-38. [Crossref] [PubMed]
5. Shadmand M, Lautze J, Md AM. Takotsubo pathophysiology and complications: what we know and what we do not know. Heart Fail Rev 2024;29:497-510. [Crossref] [PubMed]
6. Redfors B, Vedad R, Angerås O, et al. Mortality in takotsubo syndrome is similar to mortality in myocardial infarction - A report from the SWEDEHEART registry. Int J Cardiol 2015;185:282-9. [Crossref] [PubMed]
7. Vallabhajosyula S, Barsness GW, Herrmann J, et al. Comparison of Complications and In-Hospital Mortality in Takotsubo (Apical Ballooning/Stress) Cardiomyopathy Versus Acute Myocardial Infarction. Am J Cardiol 2020;132:29-35. [Crossref] [PubMed]
8. Ghadri JR, Kato K, Cammann VL, et al. Long-Term Prognosis of Patients With Takotsubo Syndrome. J Am Coll Cardiol 2018;72:874-82. [Crossref] [PubMed]
9. Arao K, Yoshikawa T, Isogai T, et al. A study of takotsubo syndrome over 9 years at the Tokyo Cardiovascular Care Unit Network Registry. J Cardiol 2023;82:93-9. [Crossref] [PubMed]
10. Isogai T, Matsui H, Tanaka H, et al. In-hospital Takotsubo syndrome versus in-hospital acute myocardial infarction among patients admitted for non-cardiac diseases: a nationwide inpatient database study. Heart Vessels 2019;34:1479-90. [Crossref] [PubMed]
11. Chong TK, Chen J, Lyu L, et al. Clinical characteristics and outcome correlates of Chinese patients with takotsubo syndrome: Results from the first Chinese takotsubo syndrome registry. Int J Cardiol 2023;387:131129. [Crossref] [PubMed]
12. Byrne RA, Rossello X, Coughlan JJ, et al. 2023 ESC Guidelines for the management of acute coronary syndromes. Eur Heart J 2023;44:3720-826. [Crossref] [PubMed]
13. Jurisic S, Gili S, Cammann VL, et al. Clinical Predictors and Prognostic Impact of Recovery of Wall Motion Abnormalities in Takotsubo Syndrome: Results From the International Takotsubo Registry. J Am Heart Assoc 2019;8:e011194. [Crossref] [PubMed]
14. Isaza N, Alashi A, Faulx J, et al. Impact of Temporal Changes in Left Ventricular Systolic Function on Outcomes in Takotsubo Cardiomyopathy. JACC Cardiovasc Imaging 2021;14:1273-4. [Crossref] [PubMed]
15. Matsushita K, Lachmet-Thébaud L, Marchandot B, et al. Incomplete Recovery From Takotsubo Syndrome Is a Major Determinant of Cardiovascular Mortality. Circ J 2021;85:1823-31. [Crossref] [PubMed]
16. Almendro-Delia M, López-Flores L, Uribarri A, et al. Recovery of Left Ventricular Function and Long-Term Outcomes in Patients With Takotsubo Syndrome. J Am Coll Cardiol 2024;84:1163-74. [Crossref] [PubMed]
17. Almendro-Delia M, Núñez-Gil IJ, Lobo M, et al. Short- and Long-Term Prognostic Relevance of Cardiogenic Shock in Takotsubo Syndrome: Results From the RETAKO Registry. JACC Heart Fail 2018;6:928-36. [Crossref] [PubMed]
18. Di Vece D, Citro R, Cammann VL, et al. Outcomes Associated With Cardiogenic Shock in Takotsubo Syndrome. Circulation 2019;139:413-5. [Crossref] [PubMed]
19. Cammann VL, Szawan KA, Stähli BE, et al. Age-Related Variations in Takotsubo Syndrome. J Am Coll Cardiol 2020;75:1869-77. [Crossref] [PubMed]
20. Agdamag AC, Patel H, Chandra S, et al. Sex Differences in Takotsubo Syndrome: A Narrative Review. J Womens Health (Larchmt) 2020;29:1122-30. [Crossref] [PubMed]
21. Abuelazm M, Saleh O, Hassan AR, et al. Sex Difference in Clinical and Management Outcomes in Patients With Takotsubo Syndrome: A Systematic Review and Meta-Analysis. Curr Probl Cardiol 2023;48:101545. [Crossref] [PubMed]
22. Arcari L, Musumeci MB, Stiermaier T, et al. Incidence, determinants and prognostic relevance of dyspnea at admission in patients with Takotsubo syndrome: results from the international multicenter GEIST registry. Sci Rep 2020;10:13603. [Crossref] [PubMed]
23. El-Battrawy I, Lang S, Ansari U, et al. Incidence and Prognostic Relevance of Cardiopulmonary Failure in Takotsubo Cardiomyopathy. Sci Rep 2017;7:14673. [Crossref] [PubMed]
24. Kato K, Di Vece D, Kitagawa M, et al. Cardiogenic shock in takotsubo syndrome: etiology and treatment. Cardiovasc Interv Ther 2024;39:421-7. [Crossref] [PubMed]
25. Schweiger V, Cammann VL, Crisci G, et al. Temporal Trends in Takotsubo Syndrome: Results From the International Takotsubo Registry. J Am Coll Cardiol 2024;84:1178-89. [Crossref] [PubMed]
26. Singh T, Joshi S, Kershaw LE, et al. Manganese-Enhanced Magnetic Resonance Imaging in Takotsubo Syndrome. Circulation 2022;146:1823-35. [Crossref] [PubMed]
27. Ojha V, Khurana R, Ganga KP, et al. Advanced cardiac magnetic resonance imaging in takotsubo cardiomyopathy. Br J Radiol 2020;93:20200514. [Crossref] [PubMed]
28. Kato K, Daimon M, Sano M, et al. Dynamic Trend of Myocardial Edema in Takotsubo Syndrome: A Serial Cardiac Magnetic Resonance Study. J Clin Med 2022;11:987. [Crossref] [PubMed]
29. Galiuto L, Crea F. Primary and secondary takotsubo syndrome: Pathophysiological determinant and prognosis. Eur Heart J Acute Cardiovasc Care 2020;9:690-3. [Crossref] [PubMed]
30. Agrawal A, Bhagat U, Yesilyaprak A, et al. Contemporary characteristics, outcomes and novel risk score for Takotsubo cardiomyopathy: a national inpatient sample analysis. Open Heart 2024;11:e002922. [Crossref] [PubMed]
31. Ford ES, Ajani UA, Croft JB, et al. Explaining the decrease in U.S. deaths from coronary disease, 1980-2000. N Engl J Med 2007;356:2388-98. [Crossref] [PubMed]
32. Wu C, Zhang QY, Li L, et al. Long-Term Prognosis of Different Reperfusion Strategies for ST-Segment Elevation Myocardial Infarction in Chinese County-Level Hospitals: Insight from China Acute Myocardial Infarction Registry. Biomed Environ Sci 2023;36:826-36. [PubMed]
33. Salamanca J, Alfonso F. Takotsubo syndrome: unravelling the enigma of the broken heart syndrome?-a narrative review. Cardiovasc Diagn Ther 2023;13:1080-103. [Crossref] [PubMed]
34. Scudiero F, Arcari L, Cacciotti L, et al. Prognostic relevance of GRACE risk score in Takotsubo syndrome. Eur Heart J Acute Cardiovasc Care 2020;9:721-8. [Crossref] [PubMed]
35. Sclafani M, Arcari L, Russo D, et al. Long-term management of Takotsubo syndrome: a not-so-benign condition. Rev Cardiovasc Med 2021;22:597-611. [Crossref] [PubMed]
36. Silverio A, Parodi G, Scudiero F, et al. Beta-blockers are associated with better long-term survival in patients with Takotsubo syndrome. Heart 2022;108:1369-76. [Crossref] [PubMed]
37. Vassiliki' Coutsoumbas G. Long-term injury after Takotsubo syndrome (stress cardiomyopathy). Eur Heart J Suppl 2020;22:E73-8. [Crossref] [PubMed]