Endothelial function and sympathetic nervous system activity in patients with Takotsubo syndrome

Takotsubo twins

Takotsubo syndrome is an intriguing condition of often stress induced reversible cardiac dysfunction mimicking myocardial infarction, but without explanatory coronary obstructions. The pathogenesis of the syndrome is not yet fully understood, though altered sympathetic regulation or response to cardiac sympathetic stimuli is likely to be involved. We present a unique and clinically detailed report of identical twin sisters, who both developed Takotsubo syndrome in association to mental stress shortly after menopause, also covering a potential relapse of disease in one of the twins, supporting the theory of a genetic contribution to the development of the syndrome proposed by previous case reports and small genetic studies.

Temporal changes within mechanical dyssynchrony and rotational mechanics in Takotsubo syndrome: A cardiovascular magnetic resonance imaging study

BACKGROUND

The pathophysiological significance of dyssynchrony and rotation in Takotsubo syndrome (TTS) is unknown. We aimed to define the influence of cardiovascular magnetic resonance feature tracking (CMR-FT) dyssynchrony and rotational mechanics in acute and during clinical course of TTS.

METHODS

This multicenter study included 152 TTS patients undergoing CMR (mean 3 days after symptom onset). Apical, midventricular and basal short axis views were analysed in a core-laboratory. Systolic torsion, diastolic recoil and dyssynchrony expressed as circumferential and radial uniformity ratio estimates (CURE and RURE: 0 to 1; 1 = perfect synchrony) were compared to a matched control group (n = 21). Follow-up CMR (n = 20 patients; mean 62 days, SD 7.2) and general follow-up (n = 136; mean 3.3 years, SD 2.4) were performed.

RESULTS

CURE was initially reduced compared to controls (p = 0.001) and recovered at follow-up (p < 0.001) as opposed to RURE (p = 0.116 and p = 0.179). CURE and RURE discriminated between ballooning patterns (p = 0.001 and p = 0.045). Recoil was generally impaired during the acute phase (p = 0.015), torsion only in highly dyssynchronous patients (p = 0.024). Diabetes (p = 0.007), physical triggers (p = 0.013) and malignancies (p = 0.001) predicted mortality. The latter showed a distinct association with impaired torsion (p = 0.042) and dyssynchrony (p = 0.047). Physical triggers and malignancies were related to biventricular impairment (p = 0.004 and p = 0.026), showing higher dyssynchrony (p < 0.01), greater reduction of left ventricular function (p < 0.001) and a strong trend towards increased mortality (p = 0.074).

CONCLUSION

Transient circumferential dyssynchrony and impaired rotational mechanics are distinct features of TTS with different severities according to the pattern of ballooning. Patients with malignancies and precipitating physical triggers frequently show biventricular affection, greater dyssynchrony and high mortality risk.

Takotsubo syndrome with severe bradycardia initiated by seizure: Is the implantation of a permanent pacemaker necessary?

Although arrhythmias are frequent in patients with Takotsubo syndrome (TTS), data on sick sinus syndrome remain elusive. Here, we report a case of TTS initiated by a seizure as a physical trigger that led to sinus arrest. The patient presented with cardiogenic shock and bradycardia which required intensive cardiovascular care. However, in the subacute phase of TTS, the sinus function recovered significantly, and pacemaker implantation was deferred.

Gender differences in acute coronary syndromes: focus on the women with ACS without an obstructing culprit lesion

INTRODUCTION

The etiologies of acute coronary syndromes (ACS) in women expand beyond the traditional paradigm of obstructive epicardial atherosclerotic disease and plaque rupture. Fundamental differences in pathobiology and presentation can partially explain the gender disparity in ACS diagnosis and management, but there is also much we do not know about the spectrum of coronary artery disease in women. Areas covered: This review seeks to explain some key differences between men and women in terms of risk factors, pathophysiology, and clinical presentations, as well as identify areas where more data are needed, focusing on women presenting with ACS but without a culprit lesion to explain their presentation. Literature search was undertaken with PubMed and Google Scholar. Expert commentary: Women with acute coronary syndromes but without plaque rupture or obstructive epicardial atherosclerosis can be difficult to diagnose and manage. Improving care in this underdiagnosed and undertreated population will require early identification of at risk patients, development of better diagnostic strategies, and standardized implementation of guideline-based therapies.

Takotsubo syndrome - adding pieces to a complex puzzle

Takotsubo syndrome, a form of acutely decompensated heart failure, has drawn interest because of its intriguing pathophysiology and therapeutic dilemmas. In their recent work in BMC Cardiovascular Disorders, Abanador-Kamper et al. describe the therapy management in these patients and add valuable information on cardiovascular magnetic resonance imaging evolution.

Takotsubo is not a cardiomyopathy

Unraveling the mechanisms underlying Takotsubo (TTS) leads to question the current inclusion of the condition within the spectrum of cardiomyopathies. Indeed, the clinical presentation and pathophysiology of TTS clearly differ from cardiomyopathies, i.e. diseases of heart muscle unexplained by abnormal loading conditions or coronary artery disease, which cannot recover spontaneously and may cause sudden death often in minimally symptomatic individuals or result in a gradual deterioration in ventricular function and end-stage heart failure. Furthermore, the term 'cardiomyopathy' can no longer be applied when functional or morphologic abnormalities of the coronary arteries leading to acute myocardial ischemia are deemed responsible for left ventricular (LV) systolic dysfunction. After 27years of investigation, time has come to recognize that patients with TTS do suffer from severe myocardial ischemia and fulfill all criteria of acute coronary syndromes, i.e. acute chest pain, typical electrocardiographic changes, cardiac troponin rise, as well as LV wall motion abnormalities. Accordingly, we propose that TTS should be labeled as an acute 'syndrome' to be included more appropriately within the spectrum of ischemic heart disease. With regard to the term 'stress', it may imply that the catecholamine surge is essential to produce the typical transient myocardial injury. Thus, the terminology 'Takotsubo (stress) syndrome' would more accurately reflect recent advances in the pathophysiology.

Pathophysiology of Takotsubo Syndrome

Originally described by Japanese authors in the 1990s, Takotsubo syndrome (TTS) generally presents as an acute myocardial infarction characterized by severe left ventricular dysfunction. TTS, however, differs from an acute coronary syndrome because patients have generally a normal coronary angiogram and left ventricular dysfunction, which extends beyond the territory subtended by a single coronary artery and recovers within days or weeks. The prognosis was initially thought to be benign, but subsequent studies have demonstrated that both short-term mortality and long-term mortality are higher than previously recognized. Indeed, mortality reported during the acute phase in hospitalized patients is ≈4% to 5%, a figure comparable to that of ST-segment-elevation myocardial infarction in the era of primary percutaneous coronary interventions. Despite extensive research, the cause and pathogenesis of TTS remain incompletely understood. The aim of the present review is to discuss the pathophysiology of TTS with particular emphasis on the role of the central and autonomic nervous systems. Different emotional or psychological stressors have been identified to precede the onset of TTS. The anatomic structures that mediate the stress response are found in both the central and autonomic nervous systems. Acute stressors induce brain activation, increasing bioavailability of cortisol and catecholamine. Both circulating epinephrine and norepinephrine released from adrenal medullary chromaffin cells and norepinephrine released locally from sympathetic nerve terminals are significantly increased in the acute phase of TTS. This catecholamine surge leads, through multiple mechanisms, that is, direct catecholamine toxicity, adrenoceptor-mediated damage, epicardial and microvascular coronary vasoconstriction and/or spasm, and increased cardiac workload, to myocardial damage, which has a functional counterpart of transient apical left ventricular ballooning. The relative preponderance among postmenopausal women suggests that estrogen deprivation may play a facilitating role, probably mediated by endothelial dysfunction. Despite the substantial improvement in our understanding of the pathophysiology of TTS, a number of knowledge gaps remain.

Evaluation of therapy management and outcome in Takotsubo syndrome

Background

To date there is no validated evidence for standardized treatment of patients with Takotsubo syndrome (TTS). Medication therapy after final TTS diagnosis remains unclear. Previous data on patient outcome is ambivalent. Aim of this study was to evaluate medication therapy in TTS and to analyze patient outcome.

Methods

Within an observational retrospective cohort study we analyzed our medical records and included 72 patients with TTS that underwent cardiovascular magnetic resonance imaging (CMR) after a median of 2 days interquartile range (IQR 1–3.5). We investigated medication therapy at discharge. Medication implementation and major adverse clinical events (MACE) were prospectively evaluated after a median follow-up of 24 months (IQR 6–43). Left ventricular function, myocardial oedema and late gadolinium enhancement were analyzed in a CMR follow-up if available.

Results

Antithrombotic therapy was recommended in 69 (96%) patients including different combinations. Antiplatelet monotherapy was prescribed in 28 (39%) patients. Dual antiplatelet therapy was recommended in 29 (40%) patients. Length of therapy duration varied from one to twelve months. Only in one case oral anticoagulation was prescribed due to apical ballooning with a left ventricular ejection fraction <30%. In all other cases oral anticoagulation was recommended due to other indications. ß-adrenoceptor antagonists and ACE inhibitors were recommended in 63 (88%), mineralocorticoid receptor antagonists were prescribed in 31 (43%) patients. After a median of 2 months (IQR 1.3–2.9) left ventricular function significantly recovered (49.1% ± 10.1 vs. 64.1% ± 5.7, P < 0.001) and myocardial oedema significantly decreased (13.5 ± 11.3 vs. 0.6% ± 2.4, P = <0.001) in the CMR follow-up. The 30-day mortality was 1%. MACE rate after 24 months was 12%.

Conclusion

Although therapy guidelines for TTS currently do not exist, we found that the majority of patients were treated with antithrombotic and heart failure therapy for up to twelve months. Left ventricular function and myocardial oedema recovered rapidly within the first two months. Outcome analysis showed a low bleeding rate and a high short-term survival. Therefore, TTS patients might benefit from antithrombotic and heart failure therapy at least for the first two months.

Activation of Inflammatory and Pro-Thrombotic Pathways in Acute Stress Cardiomyopathy

Stress cardiomyopathy (SCM) is a unique cardiac disorder that more often occurs in women. SCM presents in a similar fashion as acute myocardial infarction (AMI), with chest pain, ECG changes, and congestive heart failure. The primary distinguishing feature is the absence of thrombotic coronary occlusion in SCM. How this reduction in cardiac function occurs in the absence of coronary occlusion remains unknown. Therefore, we tested the hypothesis that a targeted proteomic comparison of patients with acute SCM and AMI might identify relevant mechanistic differences. Blood was drawn in normal controls (n = 6), women with AMI (n = 12), or women with acute SCM (n = 15). Two-week follow-up samples were available in AMI (n = 4) and SCM patients (n = 11). Relative concentrations of 1,310 serum proteins were measured in each of the 48 samples using the SOMAscan assay. Women with AMI had greater myocyte necrosis, as reflected by a higher peak troponin I concentration (AMI 32.03 ± 29.46 vs. SCM 2.68 ± 2.6 ng/ml, p < 0.05). AMI and SCM patients had equivalent reductions in left ventricular ejection fraction [LVEF (%) 39 ± 12 vs. 37 ± 12, p = 0.479]. In follow-up, women with SCM had a greater improvement in cardiac function [LVEF (%) 60 ± 7 vs. 45 ± 13, p < 0.001]. No differentially expressed proteins were detected (absolute log2-fold change >1; q < 0.05) between AMI and SCM in the acute or recovery phase. However, when we compared normal controls to patients with AMI, there was differential expression of 35 proteins. When we compared normal controls to patients with SCM, 45 proteins were differentially expressed. In comparison to normal controls, biological processes such as complement, coagulation, and inflammation were activated in both AMI and SCM. There were four proteins that showed a non-significant trend to be increased in acute SCM vs. AMI (netrin-1, follistatin-like 3, kallikrein 7, kynureninase). Despite a lesser degree of myocardial necrosis than AMI, SCM is characterized by a similar activation of inflammatory, complement, and coagulation pathways. These findings may explain reported thromboembolic complications in the short term and elevated risk of mortality in the long term of SCM.

Coincidental coronary artery disease impairs outcome in patients with takotsubo cardiomyopathy

BACKGROUND AND AIM

Takotsubo cardiomyopathy (TC) is an important differential diagnosis of coronary artery disease (CAD), mimicking acute coronary syndrome in clinical symptoms, biomarker profiles and ST-elevation in ECG. Absence of occlusive coronary disease is an essential criterion distinguishing both diseases. The aim of the study was to explore the influence of co-existing incidental CAD on poorer clinical outcomes and all-cause mortality in TC.

DESIGN, METHODS AND RESULTS

Our mono-centric study cohort constituted 114 consecutive patients diagnosed with TC between 2003 and 2015. The primary endpoint was the all-cause mortality. Additionally, we compared the incidence of thromboembolic events, life-threatening arrhythmias, cardiogenic shock and in-hospital death. There was no significant difference in gender distribution or mean age in both groups. Patients diagnosed with a co-existing CAD (n = 22), had a more pronounced cardiovascular risk profile. The all-cause mortality among patients with co-existing CAD after a 2-year follow-up was higher than those diagnosed with lone TC (22.7 vs. 5.4 %, P = 0.07). In a multivariate cox regression analysis CAD (HR 3.5, 95 %CI 1.0-11.6; P = 0.04), LVEF ≤ 35% (HR 3.8, 95% CI 0.0-0.6, P = 0.01) and cardiogenic shock (HR 3.8, 95% CI 1.2-11.3; P = 0.01) were independent predictors of the primary endpoint.

CONCLUSION

Our study reveals that co-existing CAD impairs the outcome in patients with TC. The diagnostic work-up for TC should therefore not necessarily hinge on ruling out CAD.

Endothelial dysfunction in cardiovascular disease and Flammer syndrome-similarities and differences

The endothelium has increasingly been recognized as a smart barrier and a key regulator of blood flow in micro- and macrovascular beds. Endothelial dysfunction marks a stage of atherosclerosis and is an important prognostic marker for cardiovascular disease. Yet, some people who tend to be slim and physically active and with rather low blood pressure show a propensity to respond to certain stimuli such as emotional stress with endothelial-mediated vascular dysregulation (Flammer syndrome). This leads to characteristic vascular symptoms such as cold hands but also a risk for vascular-mediated diseases such as normal-tension glaucoma. It is the aim of this review to delineate the differences between Flammer syndrome and its "counterpart" endothelial dysfunction in the context of cardiovascular diseases.

Autonomic function in Takotsubo syndrome long after the acute phase

OBJECTIVES

Although it is well documented that an exaggerated sympathetic stimulation plays a role in the development of Takotsubo Syndrome (TS) during the acute phase, only few studies have focused on autonomic adaptations in stress-induced cardiomyopathy long after the acute phase. Aim of the study was to investigate whether an impairment of the autonomic function is still present long after a TS event. This was done by comparing the response to a maximal exercise test in TS patients after apparent recovery (>1-year after the acute event) with that obtained in healthy subjects and in post-myocardial infarction (post-MI) patients.

METHODS

To assess heart rate recovery (HRR) and chronotropic response (CR), 24 TS patients, 25 healthy subjects and 22 post-MI patients underwent maximal exercise test, after at least 3 days of β-blockers wash-out.

RESULTS

HRR in TS patients (19.2±9.7bpm) was lower than in healthy subjects (27.7±8.3, p=0.003), and similar to post-MI patients (19.3±8.4; p=0.99). A decreasing CR trend (p=0.06), higher in healthy subjects (72±13%) than in TS (65±22%) and post-MI (57±21%) patients, was also found.

CONCLUSION

Compared to healthy subjects, TS patients showed a blunted parasympathetic reactivation after exercise, similar to that observed in post-MI patients, thereby suggesting that vagal control of heart rate after exercise is abnormal long after the acute presentation of TS.