Takotsubo Syndrome: Finally Emerging From the Shadows?

Takotsubo Syndrome and Coronary Artery Disease: Which Came First-The Chicken or the Egg?

Takotsubo syndrome (TTS) is a clinical condition characterized by temporary regional wall motion anomalies and dysfunction that extend beyond a single epicardial vascular distribution. Various pathophysiological mechanisms, including inflammation, microvascular dysfunction, direct catecholamine toxicity, metabolic changes, sympathetic overdrive-mediated multi-vessel epicardial spasms, and transitory ischemia may cause the observed reversible myocardial stunning. Despite the fact that TTS usually has an acute coronary syndrome-like pattern of presentation, the absence of culprit atherosclerotic coronary artery disease is often reported at coronary angiography. However, the idea that coronary artery disease (CAD) and TTS conditions are mutually exclusive has been cast into doubt by numerous recent studies suggesting that CAD may coexist in many TTS patients, with significant clinical and prognostic repercussions. Whether the relationship between CAD and TTS is a mere coincidence or a bidirectional cause-and-effect is still up for debate, and misdiagnosis of the two disorders could lead to improper patient treatment with unfavourable outcomes. Therefore, this review seeks to provide a profound understanding of the relationship between CAD and TTS by analyzing potential common underlying pathways, addressing challenges in differential diagnosis, and discussing medical and procedural techniques to treat these conditions appropriately.

Cardiovascular Nursing and Climate Change: A Call to Action From the CSANZ Cardiovascular Nursing Council

This Call to Action aims to provide key considerations for cardiovascular nursing, related to climate and environmental impacts. Strategies to optimise nursing preparation, immediate response and adaptation to climate emergencies are crucial to ensure those at greatest risk, including First Nations peoples, are protected from potentially avoidable harm. Professionals who manage climate consequences must also understand the impact of their care on the root cause of the problem.

'Bushfire Season' in Australia: Determinants of Increases in Risk of Acute Coronary Syndromes and Takotsubo Syndrome

BACKGROUND

Climate change has resulted in an increase in ambient temperatures during the summer months as well as an increase in risk of associated air pollution and of potentially disastrous bushfires throughout much of the world. The increasingly frequent combination of elevated summer temperatures and bushfires may be associated with acute increases in risks of cardiovascular events, but this relationship remains unstudied. We evaluated the individual and cumulative impacts of daily fluctuations in temperature, fine particulate matter of less than 2.5 µm (PM_2.5) pollution and presence of bushfires on incidence of acute coronary syndromes and Takotsubo syndrome.

METHODS

From November 1, 2019, to February 28, 2020, all admissions with acute coronary syndromes or Takotsubo syndrome to South Australian tertiary public hospitals were evaluated. Univariate and combined associations were sought among each of 1) maximal daily temperature, 2) PM_2.5 concentrations, and 3) presence of active bushfires within 200 km of the hospitals concerned.

RESULTS

A total of 504 patients with acute coronary syndromes and 35 with Takotsubo syndrome were studied. In isolation, increasing temperature was associated (r_s = 0.26, P = .005) with increased incidence of acute coronary syndromes, while there were similar, but nonsignificant correlations for PM_2.5 and presence of bushfires. Combinations of all these risk factors were also associated with a doubling of risk of acute coronary syndromes. No significant associations were found for Takotsubo syndrome.

CONCLUSION

The combination of high temperatures, presence of bushfires and associated elevation of atmospheric PM_2.5 concentrations represents a substantially increased risk for precipitation of acute coronary syndromes; this risk should be factored into health care planning including public education and acute hospital preparedness.

Unraveling Pathophysiology of Takotsubo Syndrome: The Emerging Role of the Oxidative Stress's Systemic Status

Takotsubo Syndrome (TTS) is usually triggered by emotional or physical stressors, thus suggesting that an increased sympathetic activity, leading to myocardial perfusion abnormalities and ventricular dysfunction, plays a major pathogenetic role. However, it remains to be elucidated why severe emotional and physical stress might trigger TTS in certain individuals but not others. Clinical research has been focused mainly on mechanisms underlying the activation of the sympathetic nervous system and the occurrence of myocardial ischemia in TTS. However, scientific evidence shows that additional factors might play a pathophysiologic role in the condition's occurrence. In this regard, a significant contribution arrived from metabolomics studies that followed the systemic response to TTS. Specifically, preliminary data clearly show that there is an interplay between inflammation, genetics, and oxidative status which might explain susceptibility to the condition. This review aims to sum up the established pathogenetic factors underlying TTS and to appraise emerging mechanisms, with particular emphasis on oxidative status, which might better explain susceptibility to the condition.

A Pilot Study on the 1H-NMR Serum Metabolic Profile of Takotsubo Patients Reveals Systemic Response to Oxidative Stress

Takotsubo syndrome (TTS) presents as an acute coronary syndrome characterized by severe left ventricular (LV) dysfunction and non-obstructive coronary artery disease that typically shows spontaneous recovery within days or weeks. The mechanisms behind TTS are mainly related to beta-adrenergic overstimulation and acute endogenous catecholamine surge, both of which could increase oxidative status that may induce further deterioration of cardiac function. Although several studies reported evidence of inflammation and oxidative stress overload in myocardial tissue of TTS models, systemic biochemical evidence of augmented oxidant activity in patients with TTS is lacking. In this study, serum samples of ten TTS patients and ten controls have been analyzed using ¹H-NMR spectroscopy. The results of this pilot study show a marked alteration in the systemic metabolic profile of TTS patients, mainly characterized by significant elevation of ketone bodies, 2-hydroxybutyrate, acetyl-L-carnitine, and glutamate levels, in contrast with a decrease of several amino acid levels. The overall metabolic fingerprint reflects a systemic response to oxidative stress caused by the stressor that triggered the syndrome’s onset.

Catecholamine Surges Cause Cardiomyocyte Necroptosis via a RIPK1-RIPK3-Dependent Pathway in Mice

Background: Catecholamine surges and resultant excessive β-adrenergic stimulation occur in a broad spectrum of diseases. Excessive β-adrenergic stimulation causes cardiomyocyte necrosis, but the underlying mechanism remains obscure. Necroptosis, a major form of regulated necrosis mediated by RIPK3-centered pathways, is implicated in heart failure; however, it remains unknown whether excessive β-adrenergic stimulation-induced cardiac injury involves necroptosis. Hence, we conducted the present study to address these critical gaps.

Methods and Results: Two consecutive daily injections of isoproterenol (ISO; 85 mg/kg, s.c.) or saline were administered to adult mixed-sex mice. At 24 h after the second ISO injection, cardiac area with Evans blue dye (EBD) uptake and myocardial protein levels of CD45, RIPK1, Ser166-phosphorylated RIPK1, RIPK3, and Ser345-phosphorylated MLKL (p-MLKL) were significantly greater, while Ser321-phosphorylated RIPK1 was significantly lower, in the ISO-treated than in saline-treated wild-type (WT) mice. The ISO-induced increase of EBD uptake was markedly less in RIPK3^−/− mice compared with WT mice (p = 0.016). Pretreatment with the RIPK1-selective inhibitor necrostatin-1 diminished ISO-induced increases in RIPK3 and p-MLKL in WT mice and significantly attenuated ISO-induced increases of EBD uptake in WT but not RIPK3^−/− mice.

Conclusions: A large proportion of cardiomyocyte necrosis induced by excessive β-adrenergic stimulation belongs to necroptosis and is mediated by a RIPK1–RIPK3-dependent pathway, identifying RIPK1 and RIPK3 as potential therapeutic targets for catecholamine surges.

Takotsubo syndrome: Does "Diabetes Paradox" exist?

BACKGROUND

Previous small-scale studies have reported conflicting findings regarding the prevalence of diabetes mellitus (DM) and its association with outcomes in patients with takotsubo syndrome (TTS) OBJECTIVE: We sought to assess the prevalence of DM and its association with outcomes in TTS patients.

METHODS

Nationwide inpatient sample (NIS) was queried to extract patient information from January 1, 2009 to September 30, 2015. Propensity score matching (PSM) was done to compare mortality and other in-hospital outcomes.

RESULTS

A total of 40,327 hospitalizations for TTS were included. The prevalence of DM in TTS was 19.3% vs 23.1% (p-value < 0.01) in patients without TTS in the NIS from 2009 to 2015. In the PSM cohort, there was no difference in in-hospital mortality (1.1% vs 1.4%; p = 0.76), stroke (1.2% vs 0.9%; p = 0.09), cardiogenic shock (3.7% vs 3.9%; p = 0.61), cardiac arrest (1.2% vs 1.2%; p = 0.94), ventricular arrhythmias (3.7% vs 3.3%; p = 0.23), circulatory support (2.1% vs 1.8%; p = 0.17), and invasive mechanical ventilation (4.9% vs 4.7%; p = 0.54) in TTS patients with versus without diabetes. In sub-group analysis, diabetes with chronic complications patients were found to have lower mortality (0.7% vs 2.0%; p = 0.04) compared to patients without diabetes and those with uncomplicated diabetes (0.6% vs 2.6%; p = 0.002).

CONCLUSIONS

Prevalence of DM was lower in TTS in comparison to patients without TTS. In addition, complicated DM patients were found to have lower in-hospital mortality. Further studies are needed to assess the mid and long-term outcomes of DM with and without chronic complications in TTS.