Differences Between Takotsubo and the Working Diagnosis of Myocardial Infarction With Nonobstructive Coronary Arteries

Impact of mechanical circulatory support on outcomes in Takotsubo syndrome complicated by cardiogenic shock: Insights from the RETAKO registry

BACKGROUND

Cardiogenic shock (CS) complicates Takotsubo syndrome (TTS), significantly affecting patient outcomes. Since avoiding catecholamines, particularly inotropic agents, is recommended in TTS, temporary mechanical circulatory support (MCS) shows promise as a bridge to recovery. However, there is no prospective data on its use in TTS.

METHODS

Patients from the prospective nationwide RETAKO registry were included and divided based on the use and type of MCS.

RESULTS

From a national TTS registry, 1591 consecutive patients were initially enrolled between 2003 and 2022. Of these, 322 patients (20.2 %) developed CS, and 31 (9.6 %) were treated with MCS [20 intra-aortic balloon pump (IABP) (64.5 %), 8 veno-arterial extracorporeal membrane oxygenation (25.8 %), and 3 Impella-CP (9.7 %)]. Compared to CS patients managed only with drugs, MCS recipients exhibited a more severe clinical profile, with worse ventricular function and more right ventricular involvement. Despite encountering more complications, such as major bleeding and atrial fibrillation, MCS did not significantly influence in-hospital mortality (19.4 % in the MCS group vs 13.1 % in the no MCS group, p = 0.33). After adjusting for other predictors of in-hospital mortality (invasive mechanical ventilation, inotropic-vasoactive score, age, and SCAI stage), MCS was not associated with higher mortality.

CONCLUSION

Approximately 10 % of TTS patients complicated by CS were treated with MCS. Despite their more severe CS, patients treated with MCS had similar in-hospital mortality rates as those treated only with drugs, suggesting a potential benefit of MCS in selected cases.

Age Variation in Patients with Troponin Level Elevation Without Obstructive Culprit Lesion or Suspected Myocardial Infarction with Non-Obstructive Coronary Arteries-Long-Term Data Covering over Decade

Background/Objectives: Troponin level elevation without an obstructive culprit lesion is caused by heterogenous entities. The effect of aging on this condition has been poorly investigated. Methods: After screening 24,775 patients between 2010 and 2021, this study included a total of 373 patients with elevated troponin levels without an obstructive culprit lesion or suspected myocardial infarction with non-obstructive coronary arteries (MINOCAs) categorized into four age groups containing 78 patients (<51 years), 72 patients (51-60 years), 81 patients (61-70 years), and 142 patients (>70 years). This study analyzed the baseline characteristics, the in-hospital complications, in-hospital mortality, and the long-term outcomes. Results: The older patients exhibited a higher rate of major adverse cardiovascular in-hospital events than those of the other age groups (15.4% in the <51-year-old group vs. 36.1% in the 51-60-year-old group vs. 33.3% in the 61-70-year-old group vs. 47.2% in the >70-year-old group; p < 0.001). However, the rate of non-sustained ventricular tachycardia (nsVT) was higher in the 51-60-year-old patients than those of the other age groups (5.6% in the 51-60-year-old group vs. 1.3% in the 61-70-year-old group vs. 0.7% in the >70-year-old group; p = 0.027). At the 11-year follow-up, cardiovascular mortality was higher among the older patients compared to that of the younger patients (3.9% in the 61-70-year-old group vs. 4.2% in the >70-year-old group, p = 0.042), while non-cardiovascular mortality was comparable between the age groups. Conclusions: The older patients with troponin level elevation without an obstructive culprit lesion experienced a higher incidence of major adverse cardiovascular events during hospitalization compared to that of the younger groups. Additionally, higher cardiovascular mortality rates were revealed in the older patients at a long-term follow-up.

Left ventricular outflow tract obstruction in Takotsubo syndrome with cardiogenic shock: prognosis and treatment

BACKGROUND

Patients with Takotsubo syndrome (TTS) who develop cardiogenic shock may present with left ventricular outflow tract obstruction (LVOTO). The prognosis and treatment of this population have not been defined in previous studies. The aim of this study is to describe the clinical presentation, management, evolution and prognosis of a subgroup of patients with TTS and cardiogenic shock according to whether they present with LVOTO or not.

METHODS

We analysed patients with TTS recruited from 2003 to 2022 in a multicentre registry. Patients were selected if they presented cardiogenic shock during their admission. This analysis was compared according to the presence or absence of LVOTO.

RESULTS

322 patients were included, 58 (18%) of whom had LVOTO. The majority were treated with vasoactive and inotropic therapy (VIT) and its use was strongly associated with having LVOTO (77.6% vs 57.6%, p<0.001). Only five (3.3%) patients without LVOTO and two (4.4%) in the LVOTO group treated with VIT developed or worsened the obstruction. Furthermore, patients with LVOTO presented higher in-hospital complications including ventricular arrhythmias (15.5% vs 8.7%, p=0.017), major bleeding (13.8% vs 6.1%, p=0.042) and acute kidney failure (48.3% vs 28.4%, p=0.003). However, at both 90 days and 5 years, the cumulative incidence of all-cause death was not significantly different between the patients with and without LVOTO (HR 1.20, 95% CI 0.60 to 2.40 for 90 days, and HR 1.69, 95% CI 0.89 to 3.21 for 5 years).

CONCLUSIONS

LVOTO is not uncommon in patients with TTS and cardiogenic shock. It is associated with a more aggressive in-hospital course and our data is unable to rule out an association between the presence of LVOTO and long-term prognosis of patients with TTS. The development or worsening of LVOTO directly related to inotropic or vasoactive support was low.

Myocardial Infarction with Non-Obstructive Coronary Arteries (MINOCA): Focus on Coronary Microvascular Dysfunction and Genetic Susceptibility

Among the most common causes of death worldwide, ischemic heart disease (IHD) is recognized to rank first. Even if atherosclerotic disease of the epicardial arteries is known as the leading cause of IHD, the presence of myocardial infarction with non-obstructive coronary artery disease (MINOCA) is increasingly recognized. Notwithstanding the increasing interest, MINOCA remains a puzzling clinical entity that can be classified by distinguishing different underlying mechanisms, which can be divided into atherosclerotic and non-atherosclerotic. In particular, coronary microvascular dysfunction (CMD), classifiable in non-atherosclerotic mechanisms, is a leading factor for the pathophysiology and prognosis of patients with MINOCA. Genetic susceptibility may have a role in primum movens in CMD. However, few results have been obtained for understanding the genetic mechanisms underlying CMD. Future studies are essential in order to find a deeper understanding of the role of multiple genetic variants in the genesis of microcirculation dysfunction. Progress in research would allow early identification of high-risk patients and the development of pharmacological, patient-tailored strategies. The aim of this review is to revise the pathophysiology and underlying mechanisms of MINOCA, focusing on CMD and actual knowledge about genetic predisposition to it.

Takotsubo syndrome: getting closer to its causes

Takotsubo syndrome (TTS) accounts for between 1 and 4% of cases presenting clinically as an acute coronary syndrome. It typically presents as a transient cardiac phenotype of left ventricular dysfunction with spontaneous recovery. More dramatic presentations may include cardiogenic shock or cardiac arrest. Despite progress in the understanding of the condition since its first description in 1990, considerable questions remain into understanding underlying pathomechanisms. In this review article, we describe the current published data on potential underlying mechanisms associated with the onset of TTS including sympathetic nervous system over-stimulation, structural and functional alterations in the central nervous system, catecholamine secretion, alterations in the balance and distribution of adrenergic receptors, the additive impact of hormones including oestrogen, epicardial coronary or microvascular spasm, endothelial dysfunction, and genetics as potentially contributing to the cascade of events leading to the onset. These pathomechanisms provide suggestions for novel potential therapeutic strategies in patients with TTS including the role of cognitive behavioural therapy, beta-blockers, and endothelin-A antagonists. The underlying mechanism of TTS remains elusive. In reality, physical or emotional stressors likely trigger through the amygdala and hippocampus a central neurohumoral activation with the local and systemic secretion of excess catecholamine and other neurohormones, which exert its effect on the myocardium through a metabolic switch, altered cellular signalling, and endothelial dysfunction. These complex pathways exert a regional activation in the myocardium through the altered distribution of adrenoceptors and density of autonomic innervation as a protective mechanism from myocardial apoptosis. More research is needed to understand how these different complex mechanisms interact with each other to bring on the TTS phenotype.

Myocardial Infarction with Non-Obstructive Coronary Arteries: A Puzzle in Search of a Solution

Background

The term myocardial infarction with non-obstructive coronary arteries (MINOCA), defines a puzzling event occurring in the absence of obstructive coronary artery disease on coronary angiography and without an overt potential cause. However, a practical diagnostic work-up is often difficult, due to the heterogeneous etiologies and pathophysiology of MINOCA. This review aims to provide a comprehensive overview focusing on epidemiology, etiopathogenesis, diagnostic tools and therapeutic strategies for subjects with MINOCA, in order to provide a prompt and accurate diagnostic work-up and an adequate therapeutic approach in this subset population.

Methods

This educational review was carried out by following the standard methods of the Cochrane Collaboration and the PRISMA statement. The terms "MINOCA" OR ("myocardial infarction" AND ("non-obstructive" OR "non-obstructive")) were searched in PubMed and Embase databases (in Title and/or Abstract) from 1st January 2003 until 31st May 2022.

Results

Etiologic findings, clinical presentation and the degree of hemodynamic impairment play a pivotal role in defining the patient's natural history and prognostic outcome, and may significantly impact on the decision-making strategies and therapeutic approaches.

Conclusions

Despite further advances in diagnostic and therapeutic strategies, MINOCA remains a challenging conundrum in clinical practice. Clinicians should be aware of the different potential etiologies and pathogenic mechanisms of MINOCA, in order to carry out a comprehensive diagnostic work-up and implement a tailored therapeutic approach.

Is Takotsubo cardiomyopathy still looking for its own nosological identity?

Despite several efforts to provide a proper nosological framework for Takotsubo cardiomyopathy (TCM), this remains an unresolved matter in clinical practice. Several clinical, pathophysiologic and histologic findings support the conceivable hypothesis that TCM could be defined as a unique pathologic entity, rather than a distinct subset of myocardial infarction with non-obstructive coronary arteries. Further investigations are needed in order to define TCM with the most appropriate disease taxonomy.

Do Patients with Myocardial Infarction with Non-Obstructive Coronary Arteries Have Similar Prognosis Compared to Ones with MI-CAD?

Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality worldwide and it is primarily caused by acute plaque disruption and coronary occlusion. Recent studies suggest that myocardial infarction with non-obstructive coronary arteries (MINOCA) also occurs but the underlying mechanisms have not been fully understood until recently. The evidence also suggests that the clinical outcomes of patients presenting with MINOCA are similar to AMI patients with obstructive coronary artery disease (MI-CAD), including all-cause mortality and major adverse cardiovascular events. The present narrative review considers the risk factors, pathological changes, and outcomes associated with MINOCA and compares them with MI-CAD.