Characterization of priMary And sEcondary STress Related takOtsubo

Background and rationale Takotsubo syndrome (TTS) is an acute and reversible form of myocardial injury often preceded by a physical or emotional trigger. Although TTS was generally considered a benign disease for its reversible nature, it is now clear that hemodynamic and electrical instability during the acute phase exposes patients to frequent serious adverse in-hospital complications. However, the pathophysiology of TTS is far from being completely understood. Consistent evidence demonstrated that the environmental events experienced by most of these patients and perceived as stressful (both physical or emotional) induce a brain activation and a stress-related response, with increasing bioavailability of local and circulating stress mediators, such as catecholamine and cortisol, which showed to play a major role in the etiology of to the "neurogenic stunning myocardium" responsible for this clinical condition. Recent studies strengthened the hypothesis of an outstanding link between the brain stress response system and heart in TTS patients using neuroimaging approach. The fundamental anatomic structures involved in the stress response are the neocortex, limbic system, reticular formation, brainstem, and spinal cord along with the hypothalamic-pituitary-adrenal axis which finally leads to cortisol secretion. In this regard, substantial structural differences in the neocortex and the limbic network (insula, amygdala, cingulate cortex, and hippocampus), have been shown among TTS patients compared to healthy controls using brain functional magnetic resonance imaging (fMRI), along with a hypoconnectivity of the central brain regions holding a regulatory function of the autonomic and limbic system. Moreover, a recent PET/TC study demonstrated that heightened limbic activity precedes the development of TTS and that patients with the highest activity of the amygdala develop the syndrome earliest, supporting the hypothesis that a neurobiological substrate may predispose them to this clinical syndrome.

Of interest, since TTS has been identified in an increasing number of hospitalized patients, an important clinical heterogeneity emerged among those affected, and clinical characteristics such as physical triggers along with acute neurologic or psychiatric disease, high troponin levels, and low ejection fraction showed to identify a specific category of individuals with TTS at higher risk of mortality and in-hospital complications. Therefore, it is recently emerging that so far two different categories of TTS patients were described, with different clinical features and risk profiles: primary TTS, which mainly affects patients after an emotional stressor, in the absence of epicardial coronary disease, with minor troponin release, slightly reduced and rapidly reversed left ventricular (LV) dysfunction and benign prognosis; the second one of secondary TTS, occurring after a physical stressor, in the presence of epicardial coronary artery disease (CAD), with major troponin release, with more severe or persistent LV dysfunction and associated with worse prognosis. An interesting hypothesis, that remains to be tested, is that only primary TTS might result from reversible left ventricular dysfunction of neurogenic origin through activation of neurons originating in the limbic system which may cause reversible vasoconstriction of coronary microvasculature, while secondary TTS may be due to a direct catecholamine-induced myocardial damage provoked by a physical trigger in patients with concomitant CAD. However, the pathophysiological determinants of primary and secondary TTS respectively have never been investigated so far as well as a different brain-heart axis activation in these two categories of TTS patients has never been demonstrated.

Myocardial dysfunction following a physical stressor has been also described in sepsis-induced cardiomyopathy, a well-known systemic complication of the cytokine storm following the host immune response to infection, which can significantly affect the prognosis of these patients. Both left ventricular systolic dysfunction (LVSD) and LV diastolic dysfunction (LVDD) have been described in the first period of severe septic shock as in secondary TTS, but except for the reversible nature of the myocardial dysfunction, clinical and echocardiographic characteristics (e.g. typical left ventricular kinetic abnormalities, electrocardiographic features, and possible detrimental effects of vasopressors use) seemed to distinguish secondary TTS from sepsis-induced cardiomyopathy, thus suggesting a different host systemic response to the same "stressors" and different pathophysiological mechanisms underlying these clinical conditions.

Biochemical profiles of primary vs. secondary TTS patients are still largely unidentified, and whether a different profile exists associated with these two categories of patients remains unknown. The known mechanisms associated with the development of TTS include elevated levels of circulating plasma catecholamines and their metabolites. TTS has been reported to be characterized by a myocardial macrophage inflammatory infiltrate and an increase in systemic proinflammatory cytokines. Indeed, recent studies reported that patients with acute TTS had elevated levels of the pro-inflammatory cytokines IL-6, IL-8 and CXCL1 in the blood, however, to the best of our knowledge no study before ever investigated the inflammatory burden on primary and secondary TTS.

A pro-inflammatory response is also known as a key pathogenetic mechanism of sepsis-induced cardiomyopathy. Indeed, pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-1-beta (IL-1β) and chemokines activated by pathogen-associated molecular patterns (PAMPs) have been implicated in the pathogenesis of the myocardial dysfunction following sepsis, as well as endothelial dysfunction and impaired endothelium-derived NO release which can alter the physiological regulation of blood flow distribution. Of note, in sepsis-induced cardiomyopathy, the altered immune response to pathogens leads to a down-regulation of β-adrenergic receptors, and to the attenuation of the adrenergic response at the cardiomyocyte level, as the opposite of what has been demonstrated in TTS. However, if different biological responses to the same stressors may underly the different clinical features of secondary TTS, sepsis-induced cardiomyopathy, and patients with sepsis/septic shock without myocardial dysfunction have never been investigated so far.

Moreover, since the importance of acute stress mediators is clear, the role of exposure to chronic stress in the pathogenesis of TTS and whether exists a difference in primary vs. secondary TTS patients remain unexplored. In this regard, hair cortisol has recently emerged as a new biomarker of long-term HPA activity, providing an alternative method for assessing the degree of psychosocial stress exposure months prior to an acute stressful event. Indeed, it has been shown that cortisol, like other serum lipophilic components, can cross the capillaries that nourish the follicle by diffusion and be incorporated into the growing hair proportionally to its circulating concentration. Indeed, since the hair grows at a speed of about 1 cm/month, the hair sampling at 6 cm from the scalp may allow to estimating the plasmatic cortisol levels up to six months earlier. Therefore, the invastigators aim at investigating if a different chronic exposure to stress, evaluated through hair cortisol analysis, may play a role in the pathogenesis of primary vs. secondary TTS.

Rationale Primary and secondary TTS showed an important clinical heterogeneity identifying two different subtypes of patients with different outcomes and risk profiles. the invastigators hypothesize that a different activation of the brain structures involved in acute stress response, as well as a different exposure to chronic stress, may subtend the different clinical and risk profiles observed in primary vs. secondary TTS patients. Moreover, the invastigators hypothesize that distinct signatures of circulating biomarkers may be associated with these two categories of TTS patients. Therefore, identifying these specific signatures may help in the diagnosis of these patients and pave the way for the identification of specific pathophysiologic pathways and the development of future therapies. In addition, as primary vs. secondary TTS showed different clinical outcomes, the invastigators hypothesize that the identification of such specific signatures may help in the prognostic stratification of TTS patients.

As well, the invastigators want to assess the different clinical features of patients with secondary TTS, sepsis-induced cardiomyopathy, and sepsis/septic shock without myocardial dysfunction, to see whether a different biological response to the same stressful event (infection) may underly different pathophysiological mechanisms.

Thus, our hypotheses are the following:

* A different activation of brain structures involved in acute stress response may subtend the different clinical and outcomes profiles observed in primary vs. secondary TTS. * A different exposure to chronic stress, evaluated through hair cortisol assay, may predispose to either primary or secondary TTS. * Specific plasma circulating biomarkers could discriminate between primary vs. secondary TTS, helping to identify the underlying pathophysiological mechanisms. * Specific plasma circulating biomarkers could discriminate between sepsis-induced cardiomyopathy, secondary TTS, and patients with sepsis/septic shock without myocardial dysfunction helping to identify the underlying pathophysiological mechanisms.

OBJECTIVES Primary Objective The primary objective of the study is to assess the activation of brain structures involved in acute stress response in primary vs. secondary TTS through Positron Emission Tomography (PET) analysis.

Secondary Objectives

1. To assess chronic stress exposure through hair cortisol levels in primary vs. secondary TTS. 2. To identify plasma circulating biomarkers in primary vs. secondary TTS both in the acute setup and at 3 months follow-up. 3. To identify if different plasma circulating biomarkers may be identified in sepsis/septic shock without cardiac dysfunction vs sepsis-induced cardiomyopathy; 4. To identify if different plasma circulating biomarkers may be identified in sepsis/septic shock without cardiac dysfunction vs. secondary TTS; 5. To identify if different plasma circulating biomarkers may be identified in sepsis-induced cardiomyopathy vs secondary TTS, underlying different pathophysiological mechanisms.

Study Design Single center prospective interventional study due to procedure (without drug nor device)

Study duration The study will last 42 months after the approval by the local Ethics Committe, of which the first 24 will be advocated to the enrolment phase, 12 to follow-up, and the following 6 to data analysis and scientific drafting.

Procedures The invastigators will evaluate demographic data (i.e., age, sex, race), classical cardiovascular risk factors, history of previous acute coronary syndromes, malignancy history, psychiatric history, and medical treatments.

At the time of coronary angiography for patients with primary or secondary TTS and within the first 48 hours for patients with sepsis or septic shock, arterial blood samples will be collected in 1 Vacuette® 9 mL CAT Serum Clot Activator tube and 4 Vacuette® 6 mL EDTA tubes. Furthermore, a hair sample of 6 cm will be collected for hair cortisol assay.

For patients with primary or secondary TTS blood samples will be collected by venipuncture with 1 Vacuette® 9 mL CAT Serum Clot Activator tube and 4 Vacuette® 6 mL EDTA tubes also at 3 months follow-up.

Blood samples will be immediately centrifuged to obtain whole blood, serum, and plasma samples, and then aliquoted into Eppendorf-type tubes. All samples wi

• Association between hair cortisol levels and Takotsubo clinical profile [Срок оценки: Up to 30 days]
• Association between IL-6 and Takotsubo clinical profile [Срок оценки: Up to 3 months]
• Association between IL-1beta and Takotsubo clinical profile [Срок оценки: Up to 3 months]
• Association between IL-10 and Takotsubo clinical profile [Срок оценки: Up to 3 months]
• Association between IL-18 and Takotsubo clinical profile [Срок оценки: Up to 3 months]
• Investigate IL-6 in sepsis/septic shock without cardiac dysfunction vs. sepsis-induced cardiomyopathy [Срок оценки: Up to 3 months]
• Investigate IL-1 beta in sepsis/septic shock without cardiac dysfunction vs. sepsis-induced cardiomyopathy [Срок оценки: Up to 3 months]
• Investigate IL-10 in sepsis/septic shock without cardiac dysfunction vs. sepsis-induced cardiomyopathy [Срок оценки: Up to 3 months]
• Investigate IL-18 in sepsis/septic shock without cardiac dysfunction vs. sepsis-induced cardiomyopathy [Срок оценки: Up to 3 months]
• Investigate IL-6 in sepsis/septic shock without cardiac dysfunction vs. secondary TTS [Срок оценки: Up to 3 months]
• Investigate IL-1 beta in sepsis/septic shock without cardiac dysfunction vs. secondary TTS [Срок оценки: Up to 3 months]
• Investigate IL-10 in sepsis/septic shock without cardiac dysfunction vs. secondary TTS [Срок оценки: Up to 3 months]