Tortuosity, Recurrent Segments, and Bridging of the Epicardial Coronary Arteries in Patients With the Takotsubo Syndrome

Update review on myocardial bridging: New insights

Myocardial bridging (MB) is a common congenital abnormality that remains asymptomatic in a large proportion of patients. The peak of clinical manifestation occurs during the third and fourth decades of life. MB provokes myocardial ischemia through different mechanisms including supply-demand mismatch, endothelial dysfunction, coronary microvascular dysfunction and external mechanical compression. The association between MB and atherosclerotic disease is controversial. Recent studies established a significant association of MB with myocardial infarction and non-obstructive coronary artery disease. The first line medical treatment is based on beta-blockers and calcium channel blockers. Ivabradine is used in second line therapy. Invasive approaches involving percutaneous coronary intervention, coronary artery bypass graft and myotomy are performed in patients with symptoms refractory to maximally tolerated medical treatment. The choice of revascularization technique depends on anatomical characteristics, clinical condition and physician experience. Available data derived from anecdotal evidence view the lack of randomized clinical trials.

An ophthalmologist with myocardial bridging developed takotsubo cardiomyopathy while operating; A case report and literature review

Key Clinical Message

Healthcare workers are prone to very high level of physical as well as emotional stress that lead to devastating health-related consequences which include but not limited to cardiovascular events that may lead to death. Recognizing the risk of Takotsubo Cardiomyopathy among healthcare worker is the main aim of this report.

Abstract

Takotsubo Cardiomyopathy (TC) is a reversible left ventricular wall motion abnormality that could not be explained by coronary artery disease and is typically precipitated by either emotional or physical stress. There is no sufficient data regarding the incidence of TC among healthcare workers and people with myocardial bridging. Here we are describing a case of an ophthalmologist with myocardial bridging who developed TC while in the operation theater.

Novel Imaging and Genetic Risk Markers in Takotsubo Syndrome

Takotsubo syndrome (TTS) is an increasingly recognized condition burdened by significant acute and long-term adverse events. The availability of novel techniques expanded the knowledge on TTS and allowed a more accurate risk-stratification, potentially guiding clinical management. The present review aims to summarize the recent advances in TTS prognostic evaluation with a specific focus on novel imaging and genetic markers. Parametric deformation analysis by speckle-tracking echocardiography, as well as tissue characterization by cardiac magnetic resonance imaging T1 and T2 mapping techniques, currently appear the most clinically valuable applications. Notwithstanding, computed tomography and nuclear imaging studies provided limited but promising data. A genetic predisposition to TTS has been hypothesized, though available evidence is still not sufficient. Although a genetic predisposition appears likely, further studies are needed to fully characterize the genetic background of TTS, in order to identify genetic markers that could assist in predicting disease recurrences and help in familial screening.

Bridging the Gap in a Rare Cause of Angina

Myocardial bridging occurs when coronary arteries run intramurally. Episodes of tachycardia can cause a dynamic obstruction that extends into diastole, compromising coronary filling time, and subsequently leading to ischaemia. Myocardial ischaemia, acute coronary syndrome, coronary spasm, myocardial stunning, arrhythmia, takotsubo cardiomyopathy, and sudden cardiac death have all been reported with bridging. Atherosclerotic plaques develop proximally in the bridge due to low shear stress and high oscillatory wall-flow. Factors affecting atherosclerotic build-up include disrupted flow patterns (particularly flow recirculation, which exacerbates LDL internalisation), cell adhesion and monocyte adhesion to the endothelium. Endothelial health depends on arterial flow patterns, given that the vessel reacts differently to various flow types, as confirmed in 3D simulations. Medication is the first-line therapy, while surgical de-roofing and coronary bypass are reserved for severe stenosis. Distinguishing physiological arterial compression from pathological stenosis is essential. Deeper bridges correlating with recurrent angina with an instantaneous wave-free ratio ≤0.89 or fractional flow reserve ≤0.80 are treated.

Current Knowledge and Future Challenges in Takotsubo Syndrome: Part 1-Pathophysiology and Diagnosis

First recognized in 1990, takotsubo syndrome (TTS) constitutes an acute cardiac condition that mimics acute myocardial infarction commonly in the absence of obstructive coronary artery disease; it is characterized by temporary left ventricular dysfunction, regularly in a circumferential apical, midventricular, or basal distribution. Considering its acute clinical presentation, coronary angiography with left ventriculography constitutes the gold standard diagnostic tool to exclude or confirm TTS. Frequently, TTS is related to severe emotional or physical stress and a subsequent increased adrenergic stimulation affecting cardiac function. Beyond clinical presentation, epidemiology, and novel diagnostic biomarkers, this review draws attention to potential pathophysiological mechanisms for the observed reversible myocardial dysfunction such as sympathetic overdrive-mediated multi-vessel epicardial spasms, microvascular dysfunction, the direct toxicity of catecholamines, lipotoxicity, and inflammation. Considering the long-term prognosis, further experimental and clinical research is indispensable to elucidate further pathophysiological mechanisms underlying TTS before randomized control trials with evidence-based therapeutic management can be performed.

Clinical characteristics of patients with takotsubo syndrome recurrence: An observational study with long-term follow-up

BACKGROUND

Research investigating takotsubo syndrome (TTS) recurrence yielded conflicting results. Aim of the present study is to describe clinical characteristics of patients with TTS recurrence in a cohort with available long-term follow-up.

METHODS

The study population included 234 TTS patients enrolled in a prospective multicenter registry, median follow-up of 1328 (407, 2526) days. To investigate factors associated with TTS recurrence, we analyzed patients with recurrence (Group A) in comparison with a subgroup of TTS patients within the whole population (group B) who had similar age, sex and median follow-up length (Group A 2280 days vs Group B 2361 days).

RESULTS

We observed 9 TTS recurrences affecting 8 patients, all women, with a rate of 0.9% patients/year. Median time to first recurrence was 1593 days (interquartile range: 950, 2516). We detected no significant differences between patients with and without recurrences regarding cardiovascular risk factors, symptoms, ECG and echocardiographic findings at presentation, discharge therapy. Physical trigger and chronic obstructive pulmonary disease (COPD) were more prevalent in patients who experienced a recurrence (75% vs 27% and 50% vs 14% with p = 0.01 and p = 0.022 respectively). Univariable Cox regression analysis identified physical trigger and history of COPD to be both associated with TTS recurrence [hazard ratio (HR) 11.4, 95% confidence interval (CI) 2.29-56.8, p = 0.003 and HR 4.94, 95% CI 1.16-20.99 p = 0.031 respectively].

CONCLUSION

TTS recurrence is relatively uncommon. Association with physical trigger and COPD would suggest a closer follow-up in this subgroup of patients.

takotsubo

Background 

Takotsubo syndrome (TTS) is a disease characterized by an acute and reversible myocardial injury typically precipitated by stressful and/or emotional triggers. Despite extensive research, its pathogenesis remains incompletely understood. Spasm of epicardial coronary arteries has been proposed as a potential pathogenic factor in TTS.

Case summary 

Herein, we report the case of a 68-year-old female admitted to the emergency department after developing chest pain in concomitance with an intense emotional stress. A diagnosis of non-ST-segment elevation myocardial infarction (NSTEMI) was made. Coronary angiography disclosed normal coronary arteries, and left ventriculography showed an inferior focal akinesia with basal and apical hyperkinesis, so that a diagnosis of ‘focal TTS’ was made. Two months later, the patient was re-admitted with NSTEMI, and repeat coronary angiography showed an irregular subocclusive stenosis of a well-developed first obtuse marginal branch. After intracoronary nitroglycerine infusion, a complete recover of the vessel patency was noted, and a diagnosis of epicardial spasm was made. Intracoronary optical coherence tomography was performed to assess a residual ‘hazy’ region, which confirmed a normal vessel morphology and a residual focal area of spasm without signs of instability.

Discussion 

Whether TTS and coronary artery spasm are two expressions of the same disease, or rather two separate entities with overlapping mechanisms remains unknown, and further research is warranted to solve this issue. Meanwhile, the opportunity of performing provocative tests for coronary spasm in patients with suspected TTS might be considered to gain more insights into this hypothesis.

Relationship between sclerostin and coronary tortuosity in postmenopausal females with non-obstructive coronary artery disease

BACKGROUND

Coronary tortuosity (CT) is commonly encountered in postmenopausal females and is usually present without obstructive lesions. Circulating sclerostin levels are elevated in postmenopausal females. In view of sclerostin's vasculoprotective effect, we aimed to find possible association between circulating sclerostin and CT.

METHOD

We prospectively enrolled 273 consecutive postmenopausal females with non-obstructive coronary artery disease diagnosed by coronary angiography. Presence and severity (by tortuosity score) of CT as well as serum sclerostin levels were assessed for each patient.

RESULTS

Patients with CT (128, 47% of study group) were significantly older (P < 0.001), with higher prevalence of hypertension (P = 0.001) and had significantly higher levels of both sclerostin (P < 0.001) and hs-CRP (P = 0.001). Multivariate binary logistic regression revealed that the presence of CT (dependent variable) was associated with high sclerostin level (OR 8.9, 95% CI: 4.9-16.2, P < 0.001). Using ROC curve analysis, Sclerostin at a cut-off value of >650 pg/ml was found to be associated with presence of CT (AUC 0.69, 95% CI: 0.61-0.75, P < 0.001) with sensitivity and specificity of 75% and 72.4%, respectively. Using Pearson's correlation analysis, significant positive correlation between sclerostin and severity of CT was found (r = 0.29, P = 0.001).

CONCLUSION

High circulating sclerostin is associated with the presence and severity of CT in postmenopausal females. This may add to the literature on the incompletely understood pathogenesis of CT.

Takotsubo syndrome: between evidence, myths, and misunderstandings

Takotsubo syndrome (TS) is an acute cardiac condition characterized by transient wall motion abnormalities mostly of the left ventricle. First described in 1990, TS has gained substantial attention during the past 15 years. However, the disease is still underdiagnosed. Prospective studies on TS are largely lacking, and the condition remains incompletely understood. In addition, significant misconceptions and misunderstandings are evident, contributing to potentially severe underestimation. Here, we review important aspects of TS with a focus on pitfalls, misinterpretations, and knowledge gaps considered important during diagnosis and management of the disease.

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.

Clinical Characteristics and Long-Term Mortality Rate in Female Patients with Takotsubo Syndrome Compared with Female Patients with ST-Elevation Acute Myocardial Infarction: A Retrospective Study from a Single Center

Background

Takotsubo syndrome (TTS) is characterized by acute transient, stress-induced, left ventricular systolic dysfunction, generally presenting with apical ballooning. It can mimic an acute coronary syndrome, but with a milder increase in cardiac enzymes and without culprit coronary artery disease on angiography. Data on long-term follow-up and survival in patients with TTS, compared with patients with ST-elevation myocardial infarction (STEMI), are scarce.

Purpose

To assess all-cause mortality rate and survival in a consecutive series of female patients with TTS compared with age- and sex-matched STEMI patients on long-term follow-up.

Methods and Results

We collected data of 65 TTS female patients (TTS group) with a mean age of 73.42 ± 11.35 years from 2001 to 2013. Collection of follow-up information was concluded for all patients in 2016. To compare the mortality and survival of TTS patients with those of the STEMI population, we used data from our STEMI Registry, a prospective registry of 7446 STEMI patients admitted from 2001 to 2013 to our cath-lab for primary percutaneous coronary intervention (p-PCI). From the registry, we selected 104 STEMI patients (STEMI group) comparable to our TTS group in terms of age (mean age of 72.33 ± 11.92 years) and sex. On follow-up examination after a median of 1000 days, the TTS group had a lower all-cause mortality rate than the STEMI group (7.69% versus 23.08%). This difference was statistically different between the two groups (log-rank test, p value = 0.03).

Conclusions

In our study, TTS and STEMI patients displayed a statistically significant difference in long-term survival. Specifically, the TTS group had a lower mortality rate than the STEMI group. This seems to suggest that TTS and STEMI are two different clinical entities with two different clinical outcomes.

The significant coronary tortuosity and atherosclerotic coronary artery disease; What is the relation?

Introduction: Although coronary tortuosity is relatively common in coronary angiograms, there is much debate over the significance of this anatomical variation. So in this study the relation between significant coronary tortuosity (SCT) and coronary artery disease (CAD) was examined.

Methods: The cross-sectional study included 737 patients (57% male) who were admitted to the hospital for a coronary angiography, based on their symptoms or non-invasive imaging. Coronary arteries defined as SCT are in the presence of either ≥3 consecutive curvatures of 90◦ to 180◦ or ≥2 consecutive curvatures of ≥180◦ measured at the end-diastole, in a major epicardial coronary artery ≥2 mm in diameter.

Results: 29.17% of the patients had SCT of which females (64.7% vs. 34.1%, P < 0.001) and higher aged persons (62.9±8.4 vs. 57.8±10.7 years ± SD; P < 0.001) were significantly associated with SCT compared to non-SCT. Left anterior descending artery (LAD), left circumflex artery (LCX) and right coronary artery (RCA) with SCT in comparison to non-SCT, had lesser probability of CAD with stenosis severity of ≥50% (34.5% vs. 46.1%; P = 0.019 and 17.7% vs. 31.1%; P = 0.001 and 27.9% vs. 43.5%; P = 0.013 respectively) and also had significant lower Gensini scores (4.1±5.3 vs. 8.4±11.9; P = 0.011; 2.1±3.4 vs. 5.2±9.5; P = 0.01 and 1.2±1.9 vs. 5.03±8.9; P < 0.001 respectively) but higher TIMI frame count (15.7±5.3 vs. 11.9±4.6; P < 0.001 and 17.1±4.4 vs. 12.7±4.4; P < 0.001 and 15.2±3.9 vs. 11.6±4.8; P < 0.001 respectively).

Conclusion: SCT is negatively correlated with CAD and there is a significant association between SCT and reduced coronary flow rate.

"Lambda-wave" ST-elevation is associated with severe prognosis in stress (takotsubo) cardiomyopathy

BACKGROUND

Persistent ST-segment elevation in acute coronary syndrome is associated with both short and long-term complications. By contrast, there is limited information about ST-elevation and its evolution during takotsubo (stress) cardiomyopathy (TTC).

AIM

To evaluate whether persistent downsloping ST-elevation in the early stages of TTC might correlate with short and long-term clinical events.

METHODS

One-hundred fifty-eight consecutive subjects with TTC were prospectively enrolled and assessed by electrocardiogram. Patients were classified in two groups according to the presence of downsloping ST-elevation ≥5 mm lasting at least 24 hr ("lambda-wave" ST-elevation group vs. without downsloping ST-elevation) in at least one/two contiguous leads.

RESULTS

Five (3.2%) patients, all female with a mean left ventricular ejection fraction 32 ± 5%, were included in the lambda-wave ST-elevation group. These patients were characterized by a higher prevalence of physical stressor (100% vs. 49%, p = 0.04) and higher admission and peak levels of troponin-I levels during hospitalization. Peak of ST-elevation in the lambda-wave ST-elevation group was reached 6 hr after admission and gradually decreased after 24 hr. In-hospital complications were observed in all the patients presenting lambda ST-elevation (100% vs. 23%, p = 0.03, OR: 29.1, p = 0.04); one patient presented endoventricular thrombosis and two died of cardiogenic shock. At long-term follow-up (mean 443 days), adverse events were observed in 80% of patients with lambda-wave ST-elevation (RR of adverse events at follow-up 32, p < 0.01).

CONCLUSION

Persistent downsloping lambda-wave ST-elevation during the acute phase of stress cardiomyopathy may be associated with a higher risk of adverse events at short and long-term follow-up.