Machine learning-based prediction of in-hospital death for patients with takotsubo syndrome: The InterTAK-ML model

AIMS

Takotsubo syndrome (TTS) is associated with a substantial rate of adverse events. We sought to design a machine learning (ML)-based model to predict the risk of in-hospital death and to perform a clustering of TTS patients to identify different risk profiles.

METHODS AND RESULTS

A ridge logistic regression-based ML model for predicting in-hospital death was developed on 3482 TTS patients from the International Takotsubo (InterTAK) Registry, randomly split in a train and an internal validation cohort (75% and 25% of the sample size, respectively) and evaluated in an external validation cohort (1037 patients). Thirty-one clinically relevant variables were included in the prediction model. Model performance represented the primary endpoint and was assessed according to area under the curve (AUC), sensitivity and specificity. As secondary endpoint, a K-medoids clustering algorithm was designed to stratify patients into phenotypic groups based on the 10 most relevant features emerging from the main model. The overall incidence of in-hospital death was 5.2%. The InterTAK-ML model showed an AUC of 0.89 (0.85-0.92), a sensitivity of 0.85 (0.78-0.95) and a specificity of 0.76 (0.74-0.79) in the internal validation cohort and an AUC of 0.82 (0.73-0.91), a sensitivity of 0.74 (0.61-0.87) and a specificity of 0.79 (0.77-0.81) in the external cohort for in-hospital death prediction. By exploiting the 10 variables showing the highest feature importance, TTS patients were clustered into six groups associated with different risks of in-hospital death (28.8% vs. 15.5% vs. 5.4% vs. 1.0.8% vs. 0.5%) which were consistent also in the external cohort.

CONCLUSION

A ML-based approach for the identification of TTS patients at risk of adverse short-term prognosis is feasible and effective. The InterTAK-ML model showed unprecedented discriminative capability for the prediction of in-hospital death.

Use of CytoSorb© Hemoadsorption in Patients on Veno-Venous ECMO Support for Severe Acute Respiratory Distress Syndrome: A Systematic Review

Acute respiratory distress syndrome (ARDS) is associated with high morbidity and mortality. Adjunct hemoadsorption is increasingly utilized to target underlying hyperinflammation derived from ARDS. This article aims to review available data on the use of CytoSorb© therapy in combination with V-V ECMO in severe ARDS, and to assess the effects on inflammatory, laboratory and clinical parameters, as well as on patient outcomes. A systematic literature review was conducted and reported in compliance with principles derived from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. When applicable, a before-and-after analysis for relevant biomarkers and clinical parameters was carried out. CytoSorb© use was associated with significant reductions in circulating levels of C-reactive protein and interleukin-6 (p = 0.039 and p = 0.049, respectively). Increases in PaO2/FiO2 reached significance as well (p = 0.028), while norepinephrine dosage reductions showed a non-significant trend (p = 0.067). Mortality rates in CytoSorb© patients tended to be lower than those of control groups of most included studies, which, however, were characterized by high heterogeneity and low power. In an exploratory analysis on 90-day mortality in COVID-19 patients supported with V-V ECMO, the therapy was associated with a significantly reduced risk of death. Based on the reviewed data, CytoSorb© therapy is able to reduce inflammation and potentially improves survival in ARDS patients treated with V-V ECMO. Early initiation of CytoSorb© in conjunction with ECMO might offer a new approach to enhance lung rest and promote recovery in patients with severe ARDS.

Cinefluoroscopy for assessment of mechanical heart valves with suspected dysfunction

Background

Mechanical heart valves (MHVs) are preferred prosthesis types in many, especially younger patients who need surgical valve replacement. Although echocardiography is most frequently performed for prosthesis assessment during follow-up, ultrasound artifacts usually preclude a precise investigation of prosthesis function. Cinefluoroscopy (CF) is a simple and effective method to analyze and quantify opening and closing of prosthesis leaflets but requires careful visualization of the valve using optimal viewing angles. Here, we investigated the quality of CF studies in clinical routine and their suitability for quantitative analysis of prosthesis function.

Methods and results

We retrospectively identified 94 patients with 118 cinefluoroscopies performed by 31 different investigators in one tertiary center from 2012 to 2021. Of 150 MHVs (98% bi-leaflet prostheses), 87 (58%) were aortic, 53 (34%) mitral, 7 (5%) tricuspid, and 5 (3%) pulmonary valve prostheses, respectively. CF studies were categorized by their suitability to quantitatively assess opening and closing angles. Visualization of valve function was “sufficient” in 23%, “suboptimal” in 46%, and “unsuitable” in 31% of the cases.

Conclusion

In clinical routine, only one-fourth of CF studies allow for a complete assessment of leaflet motion of MHVs. Although this may be in part due to the varying experience of operators, the high number of unsuitable studies suggests that optimal viewing angles may not be achievable in all patients. Further research is required to investigate standard viewing angles and anatomy after MHV implantation to improve the quality of CF studies and reduce radiation exposure of patients and operators.

First-in-man Implantation of a Cardiac Microcurrent Device for Chronic Systolic Heart Failure

Current therapies significantly improve survival and clinical endpoints in patients suffering from chronic heart failure with reduced ejection fraction (HFrEF), but most are not sufficient to reverse adverse remodeling and improve myocardial contractility. Herein, we report the first-in-man experience with a novel fully implantable device for cardiac electrical microcurrent (C-MIC) application. A 79-year-old man suffering from HFrEF (dilated cardiomyopathy, NYHA class III, left ventricular ejection fraction 30%) successfully underwent implantation of the C-MIC device through left anterolateral thoracotomy. At 30-day follow-up, no device-related complications were observed, demonstrating feasibility of C-MIC implantation in a patient suffering from HFrEF.

Is There a Sex Gap in Outcomes of Comparable Patients Supported with Left Ventricular Assist Devices?

OBJECTIVES

Historically, females were described as suffering from worse outcomes after left ventricular assist device (LVAD) implantation. However, females' preoperative conditions are unique, making direct comparisons with males challenging. This study aimed to select through propensity score (PS) matching two preoperatively comparable populations of females and males and test if any real sex-related difference exists regarding survival and adverse events after LVAD implantation.

METHODS

This retrospective single-center observational study investigated patients who received LVAD implantation between 2010 and 2018. PS matching was applied to balance preoperative heterogeneity between males and females. Primary endpoint was survival at follow-up. Secondary endpoints included perioperative outcomes and LVAD-related adverse events.

RESULTS

92 fully comparable females(n=46) and males(n=46) were selected after PS matching (median age:57 years, min-max:18-75). 26.1% of patients required preoperative mechanical circulatory support. Females needed more intraoperative fresh frozen plasma (p<0.001) and platelets transfusions (p=0.008) compared to males, but postoperative outcomes were comparable between groups. In-hospital, 1-year and 2-year survival were 78.3%, 69.6% and 65.2%, respectively, with no differences between groups. Survival probability remained comparable up to 8 years of follow-up(p=0.35). Overall, females showed a higher rate of strokes(p=0.039) compared to males in the follow-up time.

CONCLUSIONS

After reducing preoperative heterogeneity between females and males, survival after LVAD implantation does not differ based on sex. However, differences might exist in terms of higher transfusions and strokes in females. Reducing preoperative sex disparities and developing intraoperative and anticoagulation strategies which acknowledge sex-related variations might help abolishing differences in LVAD outcomes.

Computed-Tomography as First-line Diagnostic Procedure in Patients With Out-of-Hospital Cardiac Arrest

Background

Mortality after out-of-hospital cardiac arrest (OHCA) with return of spontaneous circulation (ROSC) remains high despite numerous efforts to improve outcome. For patients with suspected coronary cause of arrest, coronary angiography is crucial. However, there are other causes and potentially life-threatening injuries related to cardiopulmonary resuscitation (CPR), which can be detected by routine computed tomography (CT).

Materials and Methods

At Hannover Medical School, rapid coronary angiography and CT are performed in successfully resuscitated OHCA patients as a standard of care prior to admission to intensive care. We analyzed all patients who received CT following OHCA with ROSC over a three-year period.

Results

There were 225 consecutive patients with return of spontaneous circulation following out-of-hospital cardiac arrest. Mean age was 64 ± 13 years, 75% were male. Of them, 174 (77%) had witnessed arrest, 145 (64%) received bystander CPR, and 123 (55%) had a primary shockable rhythm. Mean time to ROSC was 24 ± 20 min. There were no significant differences in CT pathologies in patients with or without ST-segment elevations in the initial ECG. Critical CT findings qualifying as a potential cause for cardiac arrest were intracranial bleeding (N = 6), aortic dissection (N = 5), pulmonary embolism (N = 17), pericardial tamponade (N = 3), and tension pneumothorax (N = 11). Other pathologies were regarded as consequences of CPR and relevant for further treatment: aspiration (N = 62), rib fractures (N = 161), sternal fractures (N = 50), spinal fractures (N = 11), hepatic bleeding (N = 12), and intra-abdominal air (N = 3).

Conclusion

Early CT fallowing OHCA uncovers a high number of causes and consequences of OHCA and CPR. Those are relevant for post-arrest care and are frequently life-threatening, suggesting that CT can contribute to improving prognosis following OHCA.

Impact of Atrial Fibrillation on Outcome in Takotsubo Syndrome: Data From the International Takotsubo Registry

Background

Atrial fibrillation (AF) is a major risk factor for mortality. The prevalence, clinical correlates, and prognostic impact of AF in Takotsubo syndrome (TTS) have not yet been investigated in a large patient cohort. This study aimed to investigate the prevalence, clinical correlates, and prognostic impact of AF in patients with TTS.

Methods and Results

Patients with TTS were enrolled from the International Takotsubo Registry, which is a multinational network with 26 participating centers in Europe and the United States. Patients were dichotomized according to the presence or absence of AF at the time of admission. Of 1584 patients with TTS, 112 (7.1%) had AF. The mean age was higher (P<0.001), and there were fewer women (P=0.046) in the AF than in the non‐AF group. Left ventricular ejection fraction was significantly lower (P=0.001), and cardiogenic shock was more often observed (P<0.001) in the AF group. Both in‐hospital (P<0.001) and long‐term mortality (P<0.001) were higher in the AF group. Multivariable Cox regression analysis revealed that AF was independently associated with higher long‐term mortality (hazard ratio, 2.31; 95% CI, 1.50–3.55; P<0.001). Among patients with AF on admission, 42% had no known history of AF before the acute TTS event, and such patients had comparable in‐hospital and long‐term outcomes compared with those with a history of AF.

Conclusions

In patients presenting with TTS, AF on admission is significantly associated with increased in‐hospital and long‐term mortality rates. Whether antiarrhythmics and/or cardioversion are beneficial in TTS with AF should thus be tested in a future trial.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01947621.

Opportunities, controversies, and challenges of extracorporeal hemoadsorption with CytoSorb during ECMO

Extracorporeal membrane oxygenation (ECMO) is frequently used in many centers around the globe for various indications. However, prognosis is often poor even with all supportive therapies, and in many cases, clinical deterioration is associated with inflammation. Hemoadsorption with CytoSorb is a novel approach to limit the inflammatory response, and the device can be safely and easily installed into ECMO circuits. CytoSorb has been used more than 130.000 times to date, but because randomized controlled trials are largely lacking, there is substantial debate on its use. Here, experts from critical care medicine, cardiology, cardiac surgery, and perfusion technology discuss the pros and cons of this novel therapy and outline the future aspects for its clinical application and research.

Coexistence and outcome of coronary artery disease in Takotsubo syndrome

AIMS

Takotsubo syndrome (TTS) is an acute heart failure syndrome, which shares many features with acute coronary syndrome (ACS). Although TTS was initially described with angiographically normal coronary arteries, smaller studies recently indicated a potential coexistence of coronary artery disease (CAD) in TTS patients. This study aimed to determine the coexistence, features, and prognostic role of CAD in a large cohort of patients with TTS.

METHODS AND RESULTS

Coronary anatomy and CAD were studied in patients diagnosed with TTS. Inclusion criteria were compliance with the International Takotsubo Diagnostic Criteria for TTS, and availability of original coronary angiographies with ventriculography performed during the acute phase. Exclusion criteria were missing views, poor quality of angiography loops, and angiography without ventriculography. A total of 1016 TTS patients were studied. Of those, 23.0% had obstructive CAD, 41.2% had non-obstructive CAD, and 35.7% had angiographically normal coronary arteries. A total of 47 patients (4.6%) underwent percutaneous coronary intervention, and 3 patients had acute and 8 had chronic coronary artery occlusion concomitant with TTS, respectively. The presence of CAD was associated with increased incidence of shock, ventilation, and death from any cause. After adjusting for confounders, the presence of obstructive CAD was associated with mortality at 30 days. Takotsubo syndrome patients with obstructive CAD were at comparable risk for shock and death and nearly at twice the risk for ventilation compared to an age- and sex-matched ACS cohort.

CONCLUSIONS

Coronary artery disease frequently coexists in TTS patients, presents with the whole spectrum of coronary pathology including acute coronary occlusion, and is associated with adverse outcome.

TRIAL REGISTRATION

ClinicalTrials.gov number: NCT01947621.

First in man evaluation of a novel circulatory support device: Early experience with the Impella 5.5 after CE mark approval in Germany

BACKGROUND

The Abiomed Impella 5.5 (Danvers, MA) is a newly developed axial flow transaortic cardiac support device mounted on a 9 Fr steering catheter with a 21 Fr pump cannula. Impella 5.5 is intended for longer use and was approved for 30 days in 2018. This study evaluated the first-in-man series at six high-volume mechanical circulatory support centers in Germany after CE approval.

METHODS

The first 46 consecutive patients worldwide underwent implantation in six German centers between March 2018 and September 2019 for post-CE approval evaluation. The primary end-point was 30 days and 90 days all-cause mortality.

RESULTS

The mean age of patients was 59.0 ± 11.5 years, and 43 (93.4%) were men. Half of the patients had acute on chronic heart failure. The main indication for Impella 5.5 implantation was ischemic cardiomyopathy and acute myocardial infarction (47.8%). The mean support time was 15.5 ± 24.2 days (range 0-164, median 10 days (IQR = 7-19)) with a total of 712 patient-days on support. The 30 days and 90 days survival rates were 73.9% (95% CI: 63.3-88.9%) and 71.7% (95% CI: 60.7-87.1%), respectively. Additionally, 16 patients (34.8%) were weaned from the device for native heart recovery, and 19 (41.3%) were bridged to a durable device. Fifteen patients (32.6%) were mobilized to a chair, and 15 (32.6%) were ambulatory. We only noted one stroke and found no other thromboembolic complications. No aortic valve damage was observed in the study cohort. Finally, seven patients (15.2 %) had pump thrombosis, and nine (19.6 %) underwent device exchange. Sixteen patients (34.8 %) suffered from bleeding requiring transfusions during the whole treatment course. In ten patients (21.7%), the inflow cannula dislocated into the aortic root.

CONCLUSIONS

The first version of the Impella 5.5 presents promising early outcomes for patients with acute heart failure and expands the spectrum of available devices. The adverse event profile is favorable for short-term devices. Dislocations have been addressed by design changes. With increasing experience with this device, our study suggests that the indications for use will expand to other cardiac shock etiologies and may improve myocardial recovery and survival in patients with cardiogenic shock.

Prophylactic mechanical circulatory support for protected ventricular tachycardia ablation: A meta-analysis of the literature

Acute hemodynamic decompensation (AHD) during ventricular tachycardia (VT) ablation occurs in about 11% of cases. Prophylactic use of temporary mechanical circulatory support (pro-tMCS) has been applied to prevent AHD during VT ablation, but evidence supporting this practice is still lacking. This systematic review and meta-analysis assessed the procedural characteristics and outcomes of pro-tMCS for VT ablation. PubMed/Medline was screened until February 2020. Articles including adults receiving pro-tMCS for VT ablation were included, and a meta-analysis to compare proMCS and no-tMCS was performed. Primary outcome was in-hospital/30-day mortality. Five observational studies presenting 400 procedures (pro-tMCS: n = 187; no-tMCS: n = 213) were included. Baseline characteristics were comparable between groups. Impella and TandemHeart were used in 86.6% and 13.4% of cases, respectively. In the pro-tMCS group, more VTs were induced (mean difference: 0.52, confidence interval [CI]: 0.26-0.77, P < .0001), and patients remained in VT on average for 24.04 minutes longer (CI: 18.28-29.80, P < .00001). Procedural success was comparable between groups, as was VT recurrence. Pro-tMCS patients had an odds ratio of 0.55 (CI: 0.28-1.05, P = .07) for in-hospital/30-day mortality and 0.55 (CI: 0.32-0.94, P = .03) for mortality at follow-up. Sixty-four percent of no-tMCS patients received rescue tMCS. The most common tMCS-related complications were bleeding events. Pro-tMCS allowed for a prolonged time on VTs and the induction of more VTs. Although these advantages were not associated with differences in procedural success, VT recurrence, or in-hospital/30-day mortality in the overall population, pro-tMCS might improve long-term survival. Further prospective studies are urgently needed to confirm these results.

Prognostic impact of acute pulmonary triggers in patients with takotsubo syndrome: new insights from the International Takotsubo Registry

AIMS

Acute pulmonary disorders are known physical triggers of takotsubo syndrome (TTS). This study aimed to investigate prevalence of acute pulmonary triggers in patients with TTS and their impact on outcomes.

METHODS AND RESULTS

Patients with TTS were enrolled from the International Takotsubo Registry and screened for triggering factors and comorbidities. Patients were categorized into three groups (acute pulmonary trigger, chronic lung disease, and no lung disease) to compare clinical characteristics and outcomes. Of the 1670 included patients with TTS, 123 (7%) were identified with an acute pulmonary trigger, and 194 (12%) had a known history of chronic lung disease. The incidence of cardiogenic shock was highest in patients with an acute pulmonary trigger compared with those with chronic lung disease or without lung disease (17% vs. 10% vs. 9%, P = 0.017). In-hospital mortality was also higher in patients with an acute pulmonary trigger than in the other two groups, although not significantly (5.7% vs. 1.5% vs. 4.2%, P = 0.13). Survival analysis demonstrated that patients with an acute pulmonary trigger had the worst long-term outcome (P = 0.002). The presence of an acute pulmonary trigger was independently associated with worse long-term mortality (hazard ratio 2.12, 95% confidence interval 1.33-3.38; P = 0.002).

CONCLUSIONS

The present study demonstrates that TTS is related to acute pulmonary triggers in 7% of all TTS patients, which accounts for 21% of patients with physical triggers. The presence of acute pulmonary trigger is associated with a severe in-hospital course and a worse long-term outcome.

Sex differences in outcomes following less-invasive left ventricular assist device implantation

Background

Worse outcomes in women compared to men undergoing left ventricular assist device (LVAD) implantation remain an underestimated problem in heart failure (HF) patients. With device miniaturization, less-invasive LVAD implantation techniques have gained relevance, but their impact on outcomes in women is unknown. This study investigates sex-related differences in patients undergoing LVAD implantation through less-invasive procedures.

Methods

This retrospective single-center cohort study included patients who underwent isolated LVAD implantation between 2011 and 2018 through less-invasive techniques. Propensity score matching (PSM) was utilized to balance preoperative heterogeneity. Primary endpoint was two-year survival, and secondary endpoints included long-term survival, surgical outcomes and postoperative adverse events.

Results

Baseline analysis of 191 patients (females 18.3%) showed differences in terms of age [female (median, 52; IQR, 47-61); male (median, 58.5; IQR, 49-66); P=0.005], underlying diagnosis (P<0.001), INTERMACS profile (P=0.009), history of previous cardiac surgery (P=0.049) and preoperative creatinine values [female (median, 110; IQR, 71-146); male (median, 126; IQR, 9-168); P=0.049]. Over a follow-up of 460.68 patient-years, Kaplan-Meyer analysis showed better survival in females (P=0.027) and a similar probability of cardiac transplantation (P=0.288). After PSM, females showed higher needs for intraoperative fresh frozen plasma (P=0.044) and platelets (P=0.001) but comparable postoperative outcomes. No sex-related differences were noticed regarding two-year outcomes, long-term survival and adverse events. LVAD-related infections remained the most common complication with males experiencing more pump infections than women (P=0.050).

Conclusions

Patients receiving less-invasive LVAD implantation do not show significant sex-related differences in short and long-term outcomes and survival. Prospective studies are needed to evaluate the role of less-invasive techniques in reducing sex-based disparities after LVAD implantation.

Age-Related Variations in Takotsubo Syndrome

BACKGROUND

Takotsubo syndrome (TTS) occurs predominantly in post-menopausal women but is also found in younger patients.

OBJECTIVES

This study aimed to investigate age-related differences in TTS.

METHODS

Patients diagnosed with TTS and enrolled in the International Takotsubo Registry between January 2011 and February 2017 were included in this analysis and were stratified by age (younger: ≤50 years, middle-age: 51 to 74 years, elderly: ≥75 years). Baseline characteristics, hospital course, as well as short- and long-term mortality were compared among groups.

RESULTS

Of 2,098 TTS patients, 242 (11.5%) patients were ≤50 years of age, 1,194 (56.9%) were 51 to 74 years of age, and 662 (31.6%) were ≥75 years of age. Younger patients were more often men (12.4% vs. 10.9% vs. 6.3%; p = 0.002) and had an increased prevalence of acute neurological (16.3% vs. 8.4% vs. 8.8%; p = 0.001) or psychiatric disorders (14.1% vs. 10.3% vs. 5.6%; p < 0.001) compared with middle-aged and elderly TTS patients. Furthermore, younger patients had more often cardiogenic shock (15.3% vs. 9.1% vs. 8.1%; p = 0.004) and had a numerically higher in-hospital mortality (6.6% vs. 3.6% vs. 5.1%; p = 0.07). At multivariable analysis, younger (odds ratio: 1.60; 95% confidence interval: 0.86 to 3.01; p = 0.14) and older age (odds ratio: 1.09; 95% confidence interval: 0.66 to 1.80; p = 0.75) were not independently associated with in-hospital mortality using the middle-aged group as a reference. There were no differences in 60-day mortality rates among groups.

CONCLUSIONS

A substantial proportion of TTS patients are younger than 50 years of age. TTS is associated with severe complications requiring intensive care, particularly in younger patients.

Cardiac arrest in takotsubo syndrome: results from the InterTAK Registry

AIMS

We aimed to evaluate the frequency, clinical features, and prognostic implications of cardiac arrest (CA) in takotsubo syndrome (TTS).

METHODS AND RESULTS

We reviewed the records of patients with CA and known heart rhythm from the International Takotsubo Registry. The main outcomes were 60-day and 5-year mortality. In addition, predictors of mortality and predictors of CA during the acute TTS phase were assessed. Of 2098 patients, 103 patients with CA and known heart rhythm during CA were included. Compared with patients without CA, CA patients were more likely to be younger, male, and have apical TTS, atrial fibrillation (AF), neurologic comorbidities, physical triggers, and longer corrected QT-interval and lower left ventricular ejection fraction on admission. In all, 57.1% of patients with CA at admission had ventricular fibrillation/tachycardia, while 73.7% of patients with CA in the acute phase had asystole/pulseless electrical activity. Patients with CA showed higher 60-day (40.3% vs. 4.0%, P < 0.001) and 5-year mortality (68.9% vs. 16.7%, P < 0.001) than patients without CA. T-wave inversion and intracranial haemorrhage were independently associated with higher 60-day mortality after CA, whereas female gender was associated with lower 60-day mortality. In the acute phase, CA occurred less frequently in females and more frequently in patients with AF, ST-segment elevation, and higher C-reactive protein on admission.

CONCLUSIONS

Cardiac arrest is relatively frequent in TTS and is associated with higher short- and long-term mortality. Clinical and electrocardiographic parameters independently predicted mortality after CA.

Emerging therapies for right ventricular dysfunction and failure

Therapeutic options for right ventricular (RV) dysfunction and failure are strongly limited. Right heart failure (RHF) has been mostly addressed in the context of pulmonary arterial hypertension (PAH), where it is not possible to discern pulmonary vascular- and RV-directed effects of therapeutic approaches. In part, opposing pathomechanisms in RV and pulmonary vasculature, i.e., regarding apoptosis, angiogenesis and proliferation, complicate addressing RHF in PAH. Therapy effective for left heart failure is not applicable to RHF, e.g., inhibition of adrenoceptor signaling and of the renin-angiotensin system had no or only limited success. A number of experimental studies employing animal models for PAH or RV dysfunction or failure have identified beneficial effects of novel pharmacological agents, with most promising results obtained with modulators of metabolism and reactive oxygen species or inflammation, respectively. In addition, established PAH agents, in particular phosphodiesterase-5 inhibitors and soluble guanylate cyclase stimulators, may directly address RV integrity. Promising results are furthermore derived with microRNA (miRNA) and long non-coding RNA (lncRNA) blocking or mimetic strategies, which can target microvascular rarefaction, inflammation, metabolism or fibrotic and hypertrophic remodeling in the dysfunctional RV. Likewise, pre-clinical data demonstrate that cell-based therapies using stem or progenitor cells have beneficial effects on the RV, mainly by improving the microvascular system, however clinical success will largely depend on delivery routes. A particular option for PAH is targeted denervation of the pulmonary vasculature, given the sympathetic overdrive in PAH patients. Finally, acute and durable mechanical circulatory support are available for the right heart, which however has been tested mostly in RHF with concomitant left heart disease. Here, we aim to review current pharmacological, RNA- and cell-based therapeutic options and their potential to directly target the RV and to review available data for pulmonary artery denervation and mechanical circulatory support.

Use of extracorporeal membrane oxygenation for eCPR in the emergency room in patients with refractory out-of-hospital cardiac arrest

Background

Out-of-hospital cardiac arrest (OHCA) refractory to conventional high-quality cardiopulmonary resuscitation (CPR) may be rescued by extracorporeal CPR (eCPR) using veno-arterial extracorporeal membrane oxygenation (V-A ECMO). Even when trying to identify eCPR candidates based on criteria assumed to be associated with a favourable neurological outcome, reported survival rates are frequently below 10%.

Methods

All patients undergoing implantation of V-A ECMO for eCPR between January 2018 and December 2019 (N = 40) were analysed (age 53±13 years; 75% male). Patients with refractory OHCA and potentially favourable circumstances (initial shockable rhythm, witnessed arrest, bystander CPR, absence of limiting comorbidities, age <75 years) were transported under mechanical chest compression. Candidates for eCPR should have a pH ≥6.9, arterial lactate ≤15 mmol/L and time-to-ECMO should be ≤60 minutes.

Results

Overall 30-day survival was 12.5%, with 3 of 5 survivors having a favourable neurological outcome (cerebral performance category (CPC) 1 or 2), representing 7.5% of the total eCPR population. No patient selected for eCPR met all pre-defined criteria (median of unfavourable criteria: 3). Importantly, time-to-ECMO most often (39/40) exceeded 60 minutes (mean 102 ±32 min.), and lactate was >15mmol/L in 30 out of 40 patients. Moreover, 22 out of 40 patients had a non-shockable rhythm on the first ECG.

Conclusions

Despite our intention to select patients with potentially advantageous circumstances to achieve acceptable eCPR outcomes, the imminent deadly consequence of withholding eCPR obviously prompted individual physicians to perform the procedure also in presumably more unfavourable settings, resulting in similar mortality rates of eCPR as reported before.

Advanced Preconditioning: Impella 5.5 Support for Decompensated Heart Failure Before Left Ventricular Assist Device Surgery

Left ventricular assist devices (LVAD) are increasingly used in patients with advanced heart failure, and available devices and surgical techniques have strongly evolved over time. Adequate recompensation of patients before surgery is important for optimal surgical outcomes. However, patients with terminal heart failure frequently suffer from cardiorenal syndrome, which complicates recompensation by medical means. Here, we report on the use of an Impella 5.5 microaxial pump for supporting a patient with severely decompensated heart failure before LVAD implantation, which resulted in hemodynamic stabilization and effective recompensation prior to surgery.

Mechanical circulatory support for Takotsubo syndrome: a systematic review and meta-analysis

BACKGROUND

Cardiogenic shock occurs in 10%-15% of patients with Takotsubo syndrome (TS). For several reasons catecholamines, and especially inotropes, should be avoided in TS. Temporary mechanical circulatory support (MCS) appears attractive as bridge-to-recovery, but prospective studies are lacking. Here we analyze the available literature on MCS use in patients with TS.

METHODS AND RESULTS

PubMed/Medline was systematically screened until December 2019. 18 studies reporting pooled data of 5629 TS patients, of whom 227 had received MCS, were considered for a qualitative synthesis. 81 articles from 2003 through 2019 reporting individual data of 93 MCS cases were included in a meta-analysis. Median age was 57 (IQR: 43-68) years, 83.9% were women, and a physical trigger could be identified in 74.1% of cases. Median left ventricular ejection fraction (LVEF) before MCS was 20% (IQR: 15-25) and comparable between groups defined by MCS device. An apical TS type was present in 76.1% of cases. The overall number of publications on MCS for TS increased over time, as did those using veno-arterial extracorporeal membrane oxygenation (V-A ECMO) and Impella, while those using intra-aortic balloon pump declined. MCS-related complications were not regularly reported. Median time on MCS was 3 (IQR: 2-7) days, with an overall survival of 94.6%.

CONCLUSIONS

MCS for TS-related shock is increasingly reported, with a growing use of V-A ECMO and Impella. Currently available clinical data support this approach. Prospective studies are needed to evaluate safety and efficacy of different devices as well as timing of MCS in this special patient population.

Takotsubo syndrome: between evidence, myths, and misunderstandings

Takotsubo syndrome (TS) is an acute cardiac condition characterized by transient wall motion abnormalities mostly of the left ventricle. First described in 1990, TS has gained substantial attention during the past 15 years. However, the disease is still underdiagnosed. Prospective studies on TS are largely lacking, and the condition remains incompletely understood. In addition, significant misconceptions and misunderstandings are evident, contributing to potentially severe underestimation. Here, we review important aspects of TS with a focus on pitfalls, misinterpretations, and knowledge gaps considered important during diagnosis and management of the disease.

Early Escalation of Mechanical Circulatory Support Stabilizes and Potentially Rescues Patients in Refractory Cardiogenic Shock

Background:

Limited progress has been made in the management of cardiogenic shock (CS). Morbidity and mortality of refractory CS remain high. The effects of mechanical circulatory support (MCS) are promising, although many aspects are elusive. We evaluated efficacy and safety of early combined MCS (Impella microaxial pump + venoarterial extracorporeal membrane oxygenation [VA-ECMO]) in refractory CS and aimed to determine factors for decision-making in combined MCS.

Methods and Results:

We analyzed 69 consecutive patients with refractory CS from our registry requiring combined MCS. In 12 cases, therapy was actively withdrawn according to patient’s will. Patients were severely sick (Survival After Venoarterial ECMO score mean±SD, –8.9±4.4) predicting 30% in-hospital survival; ventilation 94%, dialysis 56%. Impella pumps and VA-ECMO were combined early (duration of combined MCS: median 94 hours; interquartile range, 49–150 hours). Early MCS escalation stabilized patients rapidly, reducing number and doses of catecholamines ( P <0.05 versus baseline) while hemodynamics improved. Reflecting an improved microcirculation, lactate levels normalized within 24 hours ( P <0.05 versus baseline). Despite refractory CS and disease severity, survival was favorable (on MCS 61%, 30 days 49%, 6 months 40%). In multivariate Cox-regression, duration of shock-to-first device (hours, hazard ratio, 1.05 [95% CI, 1.01–1.08]; P =0.007) and lactate levels after 12 hours of MCS (hazard ratio, 1.28 [95% CI, 1.09–1.51]; P =0.002) independently predicted survival. Additional right ventricular failure predisposed to futility (hazard ratio, 8.48 [95% CI, 1.85–38.91]; P =0.006).

Conclusions:

The early and consequent combination of MCS by Impella microaxial pumps and VA-ECMO enables stabilization and may rescue high-risk patients with refractory CS at low overall risk. Independent predictors of survival may guide prognostication, decision-making, and allocation of medical resources.

C-X-C Motif Chemokine Receptor 4 Blockade Promotes Tissue Repair After Myocardial Infarction by Enhancing Regulatory T Cell Mobilization and Immune-Regulatory Function

BACKGROUND

Acute myocardial infarction (MI) elicits an inflammatory response that drives tissue repair and adverse cardiac remodeling. Inflammatory cell trafficking after MI is controlled by C-X-C motif chemokine ligand 12 (CXCL12) and its receptor, C-X-C motif chemokine receptor 4 (CXCR4). CXCR4 antagonists mobilize inflammatory cells and promote infarct repair, but the cellular mechanisms are unclear.

METHODS

We investigated the therapeutic potential and mode of action of the peptidic macrocycle CXCR4 antagonist POL5551 in mice with reperfused MI. We applied cell depletion and adoptive transfer strategies using lymphocyte-deficient Rag1 knockout mice; DEREG mice, which express a diphtheria toxin receptor-enhanced green fluorescent protein fusion protein under the control of the promoter/enhancer region of the regulatory T (T_reg) cell-restricted Foxp3 transcription factor; and dendritic cell-depleted CD11c-Cre iDTR mice. Translational potential was explored in a porcine model of reperfused MI using serial contrast-enhanced magnetic resonance imaging.

RESULTS

Intraperitoneal POL5551 injections in wild-type mice (8 mg/kg at 2, 4, 6, and 8 days) enhanced angiogenesis in the infarct border zone, reduced scar size, and attenuated left ventricular remodeling and contractile dysfunction at 28 days. Treatment effects were absent in splenectomized wild-type mice, Rag1 knockout mice, and T_reg cell-depleted DEREG mice. Conversely, treatment effects could be transferred into infarcted splenectomized wild-type mice by transplanting splenic T_reg cells from POL5551-treated infarcted DEREG mice. Instructive cues provided by infarct-primed dendritic cells were required for POL5551 treatment effects. POL5551 injections mobilized T_reg cells into the peripheral blood, followed by enhanced T_reg cell accumulation in the infarcted region. Neutrophils, monocytes, and lymphocytes displayed similar mobilization kinetics, but their cardiac recruitment was not affected. POL5551, however, attenuated inflammatory gene expression in monocytes and macrophages in the infarcted region via T_reg cells. Intravenous infusion of the clinical-stage POL5551 analogue POL6326 (3 mg/kg at 4, 6, 8, and 10 days) decreased infarct volume and improved left ventricular ejection fraction in pigs.

CONCLUSIONS

These data confirm CXCR4 blockade as a promising treatment strategy after MI. We identify dendritic cell-primed splenic T_reg cells as the central arbiters of these therapeutic effects and thereby delineate a pharmacological strategy to promote infarct repair by augmenting T_reg cell function in vivo.

Intraventricular Thrombus Formation and Embolism in Takotsubo Syndrome

Objective:

Takotsubo syndrome (TTS) is characterized by acute left ventricular dysfunction, which can contribute to intraventricular thrombus and embolism. Still, prevalence and clinical impact of thrombus formation and embolic events on outcome of TTS patients remain unclear. This study aimed to investigate clinical features and outcomes of patients with and without intraventricular thrombus or embolism. Additionally, factors associated with thrombus formation or embolism, as well as predictors for mortality, were identified.

Approach and Results:

TTS patients enrolled in the International Takotsubo Registry at 28 centers in Australia, Europe, and the United States were dichotomized according to the occurrence/absence of intraventricular thrombus or embolism. Patients with intraventricular thrombus or embolism were defined as the ThrombEmb group. Of 1676 TTS patients, 56 (3.3%) patients developed intraventricular thrombus and/or embolism following TTS diagnosis (median time interval, 2.0 days [range, 0–38 days]). Patients in the ThrombEmb group had a different clinical profile including lower left ventricular ejection fraction, higher prevalence of the apical type, elevated levels of troponin and inflammatory markers, and higher prevalence of vascular disease. In a Firth bias-reduced penalized-likelihood logistic regression model apical type, left ventricular ejection fraction ≤30%, previous vascular disease, and a white blood cell count on admission >10×10 3 cells/μL emerged as independent predictors for thrombus formation or embolism.

Conclusions:

Intraventricular thrombus or embolism occur in 3.3% of patients in the acute phase of TTS. A simple risk score including clinical parameters associated with intraventricular thrombus formation or embolism identifies patients at increased risk.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01947621.

Mortality in Patients With Out-of-Hospital Cardiac Arrest Undergoing a Standardized Protocol Including Therapeutic Hypothermia and Routine Coronary Angiography: Experience From the HACORE Registry

OBJECTIVES

This study sought to analyze the impact of mandatory therapeutic hypothermia and cardiac catheterization in the absence of overt noncardiac cause of arrest as part of the Hannover Cardiac Resuscitation Algorithm before intensive care admission.

BACKGROUND

Despite advanced therapies, out-of-hospital cardiac arrest (OHCA) is still associated with high mortality rates. Recently, the TTM (Target Temperature Management 33°C Versus 36°C After Out-of-Hospital Cardiac Arrest)-trial caused severe uncertainty about the efficacy of and need for therapeutic hypothermia. Furthermore, the role of early coronary angiography in OHCA survivors without ST-segment elevation remains undetermined.

METHODS

In the HACORE (HAnnover Cooling REgistry) we investigated 233 consecutive patients (median age 64 [interquartile range: 53 to 74] years) with OHCA admitted to our institution between January 2011 and December 2015 who were treated according to the algorithm.

RESULTS

A total of 73% had ventricular fibrillation as primary rhythm. Return of spontaneous circulation was achieved after 20 (interquartile range: 10 to 30) min. Immediate percutaneous coronary angiography was performed in 96% and coronary angioplasty in 59% of all cases. ST-segment elevation was present in 47%. Critical coronary stenosis requiring percutaneous coronary intervention was present in 67% of patients with and 52% of patients without ST-segment elevation. Overall 30-day intrahospital mortality in this real-world registry was 37%. Patients in our local registry who matched the inclusion/exclusion criteria of the TTM-trial (n = 145) had a markedly lower 30-day mortality (27%) compared with the published trial (44%).

CONCLUSIONS

Standardized treatment of patients with OHCA following a strict protocol incorporating computed tomography, cardiac catheterization and revascularization, liberal use of active hemodynamic support in presence of shock, and mandatory therapeutic hypothermia results in mortality rates lower than previously reported.

Clinical Predictors and Prognostic Impact of Recovery of Wall Motion Abnormalities in Takotsubo Syndrome: Results From the International Takotsubo Registry

Background

Left ventricular (LV) recovery in takotsubo syndrome (TTS) occurs over a wide‐ranging interval, varying from hours to weeks. We sought to investigate the clinical predictors and prognostic impact of recovery time for TTS patients.

Methods and Results

TTS patients from the International Takotsubo Registry were included in this study. Cut‐off for early LV recovery was determined to be 10 days after the acute event. Multivariable logistic regression was used to assess factors associated with the absence of early recovery. In‐hospital outcomes and 1‐year mortality were compared for patients with versus without early recovery. We analyzed 406 patients with comprehensive and serial imaging data regarding time to recovery. Of these, 191 (47.0%) had early LV recovery and 215 (53.0%) demonstrated late LV improvement. Patients without early recovery were more often male (12.6% versus 5.2%; P=0.011) and presented more frequently with typical TTS (76.3% versus 67.0%, P=0.040). Cardiac and inflammatory markers were higher in patients without early recovery than in those with early recovery. Patients without early recovery showed unfavorable 1‐year outcome compared with patients with early recovery (P=0.003). On multiple logistic regression, male sex, LV ejection fraction <45%, and acute neurologic disorders were associated with the absence of early recovery.

Conclusions

TTS patients without early LV recovery have different clinical characteristics and less favorable 1‐year outcome compared with patients with early recovery. The factors associated with the absence of early recovery included male sex, reduced LV ejection fraction, and acute neurologic events.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01947621.

P1706Neurological outcome in patients with out-of-hospital cardiac arrest undergoing a standardised protocol including therapeutic hypothermia and routine coronary angiography

Purpose

To establish cut-offs for neuromarkers such as neuron-specific enolase (NSE) and S-100 predicting good neurological outcome for patients treated with therapeutic hypothermia with out-of-hospital cardiac arrest (OHCA) and return of spontaneous circulation (ROSC) as current cut-offs had been derived from normothermic cohorts.

Methods

Consecutive data of all patients with OHCA admitted to our institution between 01/2011 and 12/2016 were collected in a database. Patient received standard intensive care according to the Hannover Cardiac Resuscitation Algorithm (HaCRA) including mandatory hypothermia. Neurological markers such as neuron-specific enolase (NSE) and S-100 have been used to assess neurological damage following OHCA.

Results

Mean age of overall patient population (n=302) was 63±14 [54–74] years with a male predominance (77%). Cardiac arrest was witnessed in 81% and bystander cardiopulmonal resuscitation (CPR) was performed in 67%. Initial rhythm was ventricular fibrillation in 69%. ROSC had been achieved after 24±17 minutes. Hypothermia was applied in all patients. In 95% percutaneous coronary angiography and in 57% of them coronary intervention was performed. After ROSC, STEMI was present in 44%. Mechanical support was required in 19%. 30 day mortality was 44% in the total cohort. Mean NSE was 27±69 μg/l, mean NSE with good neurological outcome was 20±8.7 μg/l, highest NSE with good neurological outcome was 46 μg/l. Mean S-100 was 0.114±2.037μg/l, mean S-100 with good neurological outcome was 0.068±0.067 μg/l, highest S-100 with good neurological outcome was 0.360 μg/l.

Conclusion

Even when using a strict protocol for OHCA patients and routinely applying therapeutic hypothermia, the cut-offs for NSE and S-100 regarding good neurological outcome are similar to those reported before without therapeutic hypothermia, but they must not be used solitary to withdraw life support as even very high markers can be associated with goof neurological outcome in individual patients.

Long-Term Prognosis of Patients With Takotsubo Syndrome

BACKGROUND

Prognosis of Takotsubo syndrome (TTS) remains controversial due to scarcity of available data. Additionally, the effect of the triggering factors remains elusive.

OBJECTIVES

This study compared prognosis between TTS and acute coronary syndrome (ACS) patients and investigated short- and long-term outcomes in TTS based on different triggers.

METHODS

Patients with TTS were enrolled from the International Takotsubo Registry. Long-term mortality of patients with TTS was compared to an age- and sex-matched cohort of patients with ACS. In addition, short- and long-term outcomes were compared between different groups according to triggering conditions.

RESULTS

Overall, TTS patients had a comparable long-term mortality risk with ACS patients. Of 1,613 TTS patients, an emotional trigger was detected in 485 patients (30%). Of 630 patients (39%) related to physical triggers, 98 patients (6%) had acute neurologic disorders, while in the other 532 patients (33%), physical activities, medical conditions, or procedures were the triggering conditions. The remaining 498 patients (31%) had no identifiable trigger. TTS patients related to physical stress showed higher mortality rates than ACS patients during long-term follow-up, whereas patients related to emotional stress had better outcomes compared with ACS patients.

CONCLUSIONS

Overall, TTS patients had long-term outcomes comparable to age- and sex-matched ACS patients. Also, we demonstrated that TTS can either be benign or a life-threating condition depending on the inciting stress factor. We propose a new classification based on triggers, which can serve as a clinical tool to predict short- and long-term outcomes of TTS. (International Takotsubo Registry [InterTAK Registry]; NCT01947621).

Clinical Features and Outcomes of Patients With Malignancy and Takotsubo Syndrome: Observations From the International Takotsubo Registry

Background Clinical characteristics and outcomes of takotsubo syndrome (TTS) patients with malignancy have not been fully elucidated. This study sought to explore differences in clinical characteristics and to investigate short- and long-term outcomes in TTS patients with or without malignancy. Methods and Results TTS patients were enrolled from the International Takotsubo Registry. The TTS cohort was divided into patients with and without malignancy to investigate differences in clinical characteristics and to assess short- and long-term mortality. A subanalysis was performed comparing long-term mortality between a subset of TTS patients with or without malignancy and acute coronary syndrome (ACS) patients with or without malignancy. Malignancy was observed in 16.6% of 1604 TTS patients. Patients with malignancy were older and more likely to have physical triggers, but less likely to have emotional triggers compared with those without malignancy. Long-term mortality was higher in patients with malignancy (P<0.001), while short-term outcome was comparable (P=0.17). In a subanalysis, long-term mortality was comparable between TTS patients with malignancies and ACS patients with malignancies (P=0.13). Malignancy emerged as an independent predictor of long-term mortality. Conclusions A substantial number of TTS patients show an association with malignancy. History of malignancy might increase the risk for TTS, and therefore, appropriate screening for malignancy should be considered in these patients. Clinical Trial Registration URL: http://www.clinicaltrial.gov. Unique identifier: NCT01947621.

Clinical scenarios for use of transvalvular microaxial pumps in acute heart failure and cardiogenic shock - A European experienced users working group opinion

For patients with myocardial infarct-related cardiogenic shock (CS), urgent percutaneous coronary intervention is the recommended treatment strategy to limit cardiac and systemic ischemia. However, a specific therapeutic intervention is often missing in non-ischemic CS cases. Though drug treatment with inotropes and/or vasopressors may be required to stabilize the patient initially, their ongoing use is associated with excess mortality. Coronary intervention in unstable patients often leads to further hemodynamic compromise either during or shortly after revascularization. Support devices like the intra-aortic balloon pump failed to improve clinical outcomes in infarct-related CS. Currently, more powerful and active hemodynamic support devices unloading the left ventricle such as transvalvular microaxial pumps are available and are being increasingly used. However, as for other devices large randomized trials are not yet available, and device use is based on registry data and expert consensus. In this article, a multidisciplinary group of experienced users of transvalvular microaxial pumps outlines the pathophysiological background on hemodynamic changes in CS, the available mechanical support devices, and current guideline recommendations. Furthermore, different hemodynamic situations in several case-based scenarios are used to illustrate candidate settings and to provide the theoretic and scientific rationale for left-ventricular unloading in these scenarios. Finally, organization of shock networks, monitoring, weaning, and typical complications and their prevention are discussed.

Rationale of Hemoadsorption during Extracorporeal Membrane Oxygenation Support

Extracorporeal membrane oxygenation (ECMO) and extracorporeal life support are increasingly used for treating various forms of shock, lung failure, protected interventions and life support including resuscitation. Most patients on ECMO are affected by a systemic inflammatory response caused by the underlying disease as well as the ECMO support itself, which contributes to vasoplegia, multi-organ failure, deterioration and death. Unfortunately, effective strategies for control of inflammation and related organ failure and shock on ECMO are lacking. Recently, a new polystyrene-based device for hemoadsorption, which aims to reduce excessive levels of inflammatory molecules such as interleukins, cytokines as well as damage- and pathogen-associated molecular patterns, has become available. Here we summarize the rationale, available data and technical aspects of polystyrene-based hemoadsorption during ECMO support, and give recommendations based on existing experience.

Protected percutaneous coronary intervention with Impella CP in a patient with left main disease, severe left ventricular systolic dysfunction and established hemolysis

The use of the Impella device in patients with left ventricular (LV) systolic impairment undergoing left main (LM) percutaneous coronary intervention (PCI) has been growing exponentially. Data from observational studies and registries demonstrate that Impella-assisted high-risk PCI is safe and effective with a low rate of peri-procedural complications. Hemolysis is a potential limitation of virtually all mechanical circulatory support devices and a small incidence of hemolysis has been associated with Impella use. The safety and feasibility of Impella use in patients with established hemolysis has not been previously evaluated. We report the first described case in the literature of Impella-assisted left main stem (LMS) PCI in a patient with severe LV systolic dysfunction and autoimmune hemolytic anemia (AIHA). Despite the patient's high bleeding risk (active hemolysis, thrombocytopenia, impaired renal function, use of steroids), Impella placement and PCI were successfully performed without complication. Haemoglobin, bilirubin and lactate dehydrogenase (LDH) levels were closely monitored peri-procedurally with no evidence of exacerbation of the patient's hemolysis. We briefly discuss the mechanism of Impella-induced hemolysis and factors that can exacerbate hemolysis.

Safe Exchange of a Transfemoral Impella Pump

Mechanical circulatory support with the Impella pump is established in many centers treating patients with cardiogenic shock. While Impella pumps usually run very stable, it may still be possible that one needs to remove the pump for using the same vascular access for different reasons. Unfortunately, until now it had been nearly impossible to remove the pump while preserving arterial access without severe bleeding. Here we describe a prototypical approach of exchanging an Impella pump in a 47-year-old female supported with veno-arterial ECMO for cardiogenic shock from myocarditis. The dysfunctional Impella pump was safely removed and replaced by a new one through the same arterial access site. Continuation of active LV unloading resolved pulmonary edema, and the patient was finally bridged to ventricular assist device surgery with favorable outcome. In general, the described approach is applicable for virtually all large-bore devices with arterial access.

Takotsubo syndrome: State-of-the-art review by an expert panel - Part 1

Takotsubo syndrome (TTS) is an acute cardiac condition independent of epicardial coronary obstruction that mimics acute coronary syndrome and is characterized by acute heart failure with reversible ventricular motion abnormalities. This consensus paper is the result of a multinational effort aiming to summarize the current state of the art on TTS. Experts in the field provide a thorough and detailed review of this syndrome. Several novel and unique sections are emphasized in this document, including the current state of the art on genetics of takotsubo syndrome, microRNAs (miRs), racial differences, role of cardiac spectroscopy and intracoronary imaging, as well as mechanical circulatory support. In part 1 of this two-part manuscript, we discuss how TTS came to be known, several patterns and forms it can take in patients, epidemiology and pathophysiology of the syndrome, and clinical presentation.