Angiographic assessment of myocardial perfusion in Tako-Tsubo syndrome

The Evolving Features of Takotsubo Syndrome

PURPOSE OF THE REVIEW

Takotsubo syndrome (TTS) is a transient form of left ventricular dysfunction, typically affecting post-menopausal females, often preceded by emotional or physical stressful events that act as triggers. Initially believed to be a rare and benign condition for its reversible nature, TTS has recently emerged as a complex multifaceted clinical entity, with heterogenous clinical presentations and a non-negligible risk of serious in-hospital complications, including acute heart failure, arrhythmias and death.

RECENT FINDINGS

Emerging pathophysiological hypotheses, ranging from microvascular dysfunction to systemic inflammation, offer new insights into the underlying mechanisms of TTS. Moreover, increasing awareness of potential complications during the acute phase of the disease underscores its significant prognostic implications and emphasizes the need for randomized clinical trials to guide the therapeutic management of TTS. In this narrative review article, we aim to discuss the recent insights on the epidemiology, pathophysiology, treatment and prognosis of patients affected by TTS discussing the emerging evidence and the remaining knowledge gap in the field.

Coronary Slow-Flow Phenomenon in Takotsubo Syndrome: The Prevalence, Clinical Determinants, and Long-Term Prognostic Impact

Patients with takotsubo syndrome (TTS) may present coronary slow flow (CSF) in angiography performed in the acute myocardial infarction (MI). However, the detailed clinical relevance and its long-term impact remain poorly understood. Among 7771 MI patients hospitalized between 2012 and 2019, TTS was identified in 82 (1.1%) subjects. The epicardial blood flow was assessed with thrombolysis in myocardial infarction (TIMI) scale and corrected TIMI frame count (TFC), whereas myocardial perfusion with TIMI myocardial perfusion grade (TMPG). CSF was defined as TIMI-2 or corrected TFC > 27 frames in at least one epicardial vessel. CSF was identified in 33 (40.2%) TTS patients. In the CSF-TTS versus normal-flow-TTS group, lower values of left ventricular ejection fraction on admission (33.5 (25-40) vs. 40 (35-45)%, p = 0.019), more frequent midventricular TTS (27.3 vs. 8.2%, p = 0.020) and the coexistence of both physical and emotional triggers (9.1 vs. 0%, p = 0.032) were noted. Within a median observation of 55 months, higher all-cause mortality was found in CSF-TTS compared with normal-flow TTS (30.3 vs. 10.2%, p = 0.024). CSF was identified as an independent predictor of long-term mortality (hazard ratio 10.09, 95% confidence interval 2.12-48.00, p = 0.004). CSF identified in two-fifths of TTS patients was associated with unfavorable long-term outcomes.

Coronary blood flow in heart failure: cause, consequence and bystander

Heart failure is a clinical syndrome where cardiac output is not sufficient to sustain adequate perfusion and normal bodily functions, initially during exercise and in more severe forms also at rest. The two most frequent forms are heart failure of ischemic origin and of non-ischemic origin. In heart failure of ischemic origin, reduced coronary blood flow is causal to cardiac contractile dysfunction, and this is true for stunned and hibernating myocardium, coronary microembolization, myocardial infarction and post-infarct remodeling, possibly also for the takotsubo syndrome. The most frequent form of non-ischemic heart failure is dilated cardiomyopathy, caused by genetic mutations, myocarditis, toxic agents or sustained tachyarrhythmias, where alterations in coronary blood flow result from and contribute to cardiac contractile dysfunction. Hypertrophic cardiomyopathy is caused by genetic mutations but can also result from increased pressure and volume overload (hypertension, valve disease). Heart failure with preserved ejection fraction is characterized by pronounced coronary microvascular dysfunction, the causal contribution of which is however not clear. The present review characterizes the alterations of coronary blood flow which are causes or consequences of heart failure in its different manifestations. Apart from any potentially accompanying coronary atherosclerosis, all heart failure entities share common features of impaired coronary blood flow, but to a different extent: enhanced extravascular compression, impaired nitric oxide-mediated, endothelium-dependent vasodilation and enhanced vasoconstriction to mediators of neurohumoral activation. Impaired coronary blood flow contributes to the progression of heart failure and is thus a valid target for established and novel treatment regimens.

Coronary slow flow is associated with a worse clinical outcome in patients with Takotsubo syndrome

Objective

Patients with Takotsubo syndrome (TTS) present an acute microvascular dysfunction that leads to an impaired myocardial perfusion and, in more severe forms, an impaired epicardial flow. However, clinical relevance of a delayed coronary flow, the coronary slow flow (CSF), has never been investigated. We studied the prognostic value of CSF occurring in the acute phase of TTS.

Methods

This cohort study prospectively evaluated patients with a diagnosis of TTS. CSF was defined as angiographically non-obstructive coronary arteries with thrombolysis in myocardial infarction-2 flow. The incidence of overall mortality and major adverse cardiovascular events (MACEs), defined as the composite of TTS recurrence, cardiac rehospitalisation, cerebrovascular events and mortality, was assessed at follow-up.

Results

We enrolled 101 patients (mean age 71.0±11.1 years, 86 (85.1%) female); CSF occurred in 18 (17.8%) patients. At admission, patients with CSF presented more frequently with Killip class III/IV, moderate-to-severe left ventricle systolic dysfunction and right ventricle dysfunction. During the index admission, patients with CSF had a higher rate of intrahospital complications (12 (66.7%) vs 28 (33.7%), p=0.01). At long-term follow-up, patients with CSF had a significantly higher occurrence of overall mortality (9 (50%) vs 19 (22.9%), p=0.011), mainly due to non-cardiac causes (89.3%), and a higher rate of MACE (10 (55.5%) vs 27 (32.5%), p=0.06). At multivariable Cox regression, CSF was independently associated with death from any causes.

Conclusions

Patients with TTS presenting with CSF have a worse clinical presentation with a higher rate of intrahospital complications and a poor long-term clinical outcome.

An Emerging Cardiovascular Disease: Takotsubo Syndrome

Takotsubo syndrome (TTS) is a recently identified cardiac disease, which is far from being completely known. The aims of this narrative review are to provide a better understanding of the pathophysiological features of TTS and to update clinical findings in order to improve the management of subjects affected by this syndrome (according to the most recent consensus papers issued by the international scientific societies). We based our search on the material obtained via PubMed up to April 2019. The terms used were "Takotsubo Syndrome and Takotsubo cardiomyopathy" in combination with "heart failure, pathophysiology, complications, diagnosis, and treatment." TTS is a reversible form of ventricular dysfunction usually characterized by akinesia of the apex in the absence of obstructive coronary artery disease. In its initial phase, TTS may be indistinguishable from AMI and is usually triggered by a sudden emotional/physical stressor which abruptly increases catecholamine levels. However, the mechanisms by which catecholamines or other unidentified molecules can cause myocardial dysfunction is unknown. In-hospital stay may be hampered by various life-threatening complications, while data on long-term survival remain scarce and unclear. Furthermore, TTS may sometimes recur. We believe that TTS is clearly a much more complex condition than previously thought. Much remains to be discovered about its pathophysiologic mechanisms, the role of the link between the heart and brain and that of triggering factors and gender, and the reasons why this syndrome displays different phenotypes and sometimes recurs. Undoubtedly, preliminary evidence from pathophysiological studies (mainly genetic studies) has shown promising advances. However, prospective randomized clinical trials are still needed in order to identify and to tailor the best medical treatments for TTS patients.

Treatment strategies in coronary microvascular dysfunction: A systematic review of interventional studies

CMD has been associated with a wide spectrum of diseases and conditions, and it has proven to be a strong prognostic marker of morbidity and mortality. Despite increased attention, guideline-based treatment recommendations are lacking. We performed a systematic review of pharmacological and nonpharmacological interventions to improve coronary perfusion, assessed by IC Doppler, TTDE, PET, CMRI, transthoracic contrast perfusion echocardiography, and dilution techniques. No restrictions were made regarding the study design (randomized, placebo-controlled/randomized with active comparators/nonrandomized with or without a control group), the cardiac condition studied, or the coronary microvascular function at baseline. An electronic database search yielded 4485 records of which 80 studies met our inclusion criteria. Included studies were sorted according to intervention and study design. Studies were small and heterogeneous in methodology, and only few were placebo-controlled. Although some treatments looked promising, we found that no specific treatment was sufficiently well documented to be recommended in any patient groups. There is a need for larger well-designed clinical trials, and we suggest that future studies stratify study populations according to pathogenic mechanisms, thereby investigating whether an individualized treatment approach would be more successful.

Stress Cardiomyopathy Diagnosis and Treatment: JACC State-of-the-Art Review

Stress cardiomyopathy is an acute reversible heart failure syndrome initially believed to represent a benign condition due to its self-limiting clinical course, but now recognized to be associated with a non-negligible rate of serious complications such as ventricular arrhythmias, systemic thromboembolism, and cardiogenic shock. Due to an increased awareness and recognition, the incidence of stress cardiomyopathy has been rising (15-30 cases per 100,000 per year), although the true incidence is unknown as the condition is likely underdiagnosed. Stress cardiomyopathy represents a form of neurocardiogenic myocardial stunning, and while the link between the brain and the heart is established, the exact pathophysiological mechanisms remain unclear. We herein review the proposed risk factors and triggers for the syndrome and discuss a practical approach to diagnosis and treatment of the patients with stress cardiomyopathy, highlighting potential challenges and unresolved questions.

Takotsubo Cardiomyopathy: One More Angiographic Evidence of Microvascular Dysfunction

Background

Takotsubo cardiomyopathy (TC) aetiology has not been completely understood yet. One proposed pathogenic mechanism was coronary microvascular dysfunction (MVD). This study compared coronary flow and myocardial perfusion in patients with TC, microvascular angina (MVA), and a control group (CG).

Methods

Out of 42 consecutive patients presented to our centre with TC from 2013 to 2017; we retrospectively selected 27 patients. We compared them with a sex- and age-matched group of 27 MVA cases and 27 patients with normal coronary arteries (CG). The flow was evaluated in the three coronary arteries as TIMI flow and TIMI frame count (TFC). Myocardial perfusion was studied with Blush-Score and Quantitative Blush Evaluator (QuBE).

Results

TFC, in TC, revealed flow impairment in the three arteries compared to the CG (left anterior descending artery (LAD): 22 ± 8, 15 ± 4; p = 0.001) (right coronary artery: 12 ± 4, 10 ± 3; p = 0,025) (left circumflex: 14 ± 4, CG 11 ± 3; p = 0,006). QuBE showed myocardial perfusion impairment in the LAD territory in TC comparing with both the CG (8,9 (7,2-11,5) versus 11,4 (10-15,7); p = 0,008) and the MVA group (8,9 (7,2-11,5) versus 13,5 (10-16); p = 0,006).

Conclusions

Our study confirmed that coronary flow is impaired in TC, reflecting a MVD. Myocardial perfusion defect was detected only in the LAD area.

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.

Characteristics of coronary microcirculatory function in patients with Takotsubo syndrome

BACKGROUND

Takotsubo syndrome (TS) is a recently described cardiac syndrome whose pathogenesis is still unclear. We investigated the characteristics of coronary microcirculatory function in patients with TS through the analysis of the TIMI frame count (TFC) compared to normal subjects and with to subjects with microvascular angina (MA).

METHODS

We enrolled 71 TS patients (F:M =69:2, mean age of 65.27±9.53 years), 70 controls (F:M =34:36, mean age of 56.63±13.5 years) and 71 patients with MA, (F:M =69:2, mean age of 65.9±9.2 years). The assessment of the microcirculation was carried out through the TFC.

RESULTS

microcirculation was significantly altered in patients with TS compared with healthy controls [left anterior descending coronary artery (LAD) 25.16±6.91 vs. 17.30±3.76, P<0.001; circumflex artery (CX) 25.48±6.10 vs. 17.05±4.60, P<0.001; right coronary artery (RCA) 26.43±8.95 vs. 15.74±4.27, P<0.001, average TFC in TS 25.70±5.34 vs. 16,70±3.26, P<0.001). A TFC >20 frames was able to discriminate TS patients from controls with a specificity of 88.57% and sensitivity of 85.92% (AUC 0.927, P<0.0001). Microvascular dysfunction was diffuse in TS as well as in MA and slightly more severe in this last (mean TFC in MA 28.25±9.3 vs. 25.7±5.34 in TS, P<0.046).

CONCLUSIONS

Coronary microcirculation in TS patients is diffuse and milder compared to MA patients. Cut-off values >20 frames discriminate between patients with normal microcirculation and patients with TS.

Stress-induced cardiomyopathy

OBJECTIVES

Reversible stress-induced cardiac dysfunction is frequently seen as a complication of a multitude of acute stress states, in particular neurologic injuries. This dysfunction may be difficult to distinguish between that caused by myocardial ischemia and may impact both the treatment strategies and prognosis of the underlying condition. Critical care practitioners should have an understanding of the epidemiology, pathophysiology, clinical characteristics, precipitating conditions, differential diagnosis, and proposed treatments for stress-induced cardiomyopathy.

DATA SOURCES

MEDLINE database search conducted from inception to August 2014, including the search terms "tako-tsubo," "stress-induced cardiomyopathy," "neurogenic cardiomyopathy," "neurogenic stress cardiomyopathy," and "transient left ventricular apical ballooning syndrome". In addition, references from pertinent articles were used for a secondary search.

STUDY SELECTION AND DATA EXTRACTION

After review of peer-reviewed original scientific articles, guidelines, and reviews resulting from the literature search described above, we made final selections for included references and data based on relevance and author consensus.

DATA SYNTHESIS

Stress-induced cardiomyopathy occurs most commonly in postmenopausal women. It can be precipitated by emotional stress, neurologic injury, and numerous other stress states. Patients may present with symptoms indistinguishable from acute coronary syndrome or with electrocardiogram changes and wall motion abnormalities on echocardiogram following neurologic injury. Nearly all patients will have an elevated cardiac troponin. The underlying etiology is likely related to release of catecholamines, both locally in the myocardium and in the circulation. Differential diagnosis includes myocardial infarction, myocarditis, neurogenic pulmonary edema, and nonischemic cardiomyopathy. Although the natural course of stress-induced cardiomyopathy is resolution, treatment strategies include sympathetic blockade and supportive care.

CONCLUSIONS

Stress-induced cardiomyopathy may mimic myocardial infarction and is an important condition to recognize in patients with underlying stress states, particularly neurologic injuries.

Anabolic androgenic steroid-induced Takotsubo cardiomyopathy

Anabolic steroid abuse, aimed at increasing muscle mass, has been growing in recent years. We describe a case of a 25-year-old bodybuilder who, after taking nandrolone and stanozolol, presented with Takotsubo syndrome. The angiography showed a normal coronary anatomy with the absence of stenosis. The left ventricular function was completely normalised after 1 week.