Recurrent Takotsubo Syndrome: How Frequent, and How Does It Present?

BACKGROUND

Recurrent Takotsubo syndrome (TS) is not uncommon but experience with TS recurrence is inherently limited by the infrequency of the condition itself and incomplete long-term follow-up. There is limited published data on the clinical features and outcomes of patients with recurrent TS. We aimed to describe the clinical characteristics and outcomes of patients with recurrent TS in a large Auckland cohort.

METHOD

The clinical profile, in-hospital, and long-term outcomes were prospectively assessed in consecutive patients with recurrent TS presenting to Auckland's three major hospitals between January 2006 and January 2023.

RESULTS

During the study period, 472 TS patients were identified. Of the 467 patients discharged alive after the index event, 45 (9.6%) patients (mean age 62.3±11.0 years), all women, experienced recurrent TS. Median time interval from index event to the first recurrence was 3.14 years (range 27 days to 13.8 years). In 27 (60%) of the 45 patients, the subsequent events involved a stressor (physical triggers, n=8; emotional triggers, n=19). The stressor type differed between the index and recurrent event in 18 (40%) of the 45 patients. Thirteen (28.9%) had a different echocardiographic variant of TS at first recurrence. All patients with recurrent TS were discharged alive. Four patients died late after discharge from the first recurrence, all but one from a non-cardiac cause.

CONCLUSIONS

One in 10 patients with TS experience recurrent events. These may occur many years later, and both the stressor type and the echocardiographic variant may be different at the recurrent event.

External Validation of a Clinical Score to Differentiate Takotsubo Syndrome From Non-ST-Elevation Myocardial Infarction in Women

BACKGROUND AND AIMS

Clinical presentation of Takotsubo Syndrome (TS) mimics acute coronary syndrome (ACS). A score to differentiate TS from ACS would be helpful to facilitate appropriate investigation and management. We have previously developed a clinical score (NSTE-Takotsubo Score) to distinguish women with non-ST-segment elevation myocardial infarction (NSTEMI) from TS with non-ST-segment elevation (NSTE-TS). This study sought to assess the diagnostic validity of this score in an external validation cohort.

METHODS

The external cohort consisted of women with NSTE-TS (n=110) and NSTEMI (n=113) from two major tertiary hospitals in New Zealand. The five variables in the arithmetic score (range -6 to +5) and their relative weights are: T-wave inversion (TWI) in ≥6 leads (3 points), recent stress (2 points), diabetes mellitus (DM) (-1 point), prior cardiovascular disease (CVD) (-2 points) and presence of ST depression (-3 points). Two clinicians blinded to the diagnoses calculated the score using clinical and electrocardiogram (ECG) data on day 1 post-admission.

RESULTS

The NSTE-Takotsubo Score discriminated well between NSTE-TS and NSTEMI. The sensitivity and specificity of a score ≥1 to distinguish NSTE-TS from NSTEMI were 78% and 85%, respectively. The area under the receiver operator curve was 0.78 (95% CI 0.72 to 0.84).

CONCLUSION

In an external validation cohort, the NSTE-Takotsubo Score was easy to apply and useful to identify women likely to have NSTE-TS on day 1 post-admission.

Drug-Initiated Activity Metabolomics Identifies Myristoylglycine as a Potent Endogenous Metabolite for Human Brown Fat Differentiation

Worldwide, obesity rates have doubled since the 1980s and in the USA alone, almost 40% of adults are obese, which is closely associated with a myriad of metabolic diseases such as type 2 diabetes and arteriosclerosis. Obesity is derived from an imbalance between energy intake and consumption, therefore balancing energy homeostasis is an attractive target for metabolic diseases. One therapeutic approach consists of increasing the number of brown-like adipocytes in the white adipose tissue (WAT). Whereas WAT stores excess energy, brown adipose tissue (BAT) can dissipate this energy overload in the form of heat, increasing energy expenditure and thus inhibiting metabolic diseases. To facilitate BAT production a high-throughput screening approach was developed on previously known drugs using human Simpson-Golabi-Behmel Syndrome (SGBS) preadipocytes. The screening allowed us to discover that zafirlukast, an FDA-approved small molecule drug commonly used to treat asthma, was able to differentiate adipocyte precursors and white-biased adipocytes into functional brown adipocytes. However, zafirlukast is toxic to human cells at higher dosages. Drug-Initiated Activity Metabolomics (DIAM) was used to investigate zafirlukast as a BAT inducer, and the endogenous metabolite myristoylglycine was then discovered to mimic the browning properties of zafirlukast without impacting cell viability. Myristoylglycine was found to be bio-synthesized upon zafirlukast treatment and was unique in inducing brown adipocyte differentiation, raising the possibility of using endogenous metabolites and bypassing the exogenous drugs to potentially alleviate disease, in this case, obesity and other related metabolic diseases.

Spontaneous coronary artery dissection: insights from computed tomography coronary angiography follow-up

METHODS

Patients with SCAD on invasive coronary angiography who underwent a follow-up CTCA between 2010 and 2018 at our institute were included. CTCA was reported by two cardiologists-one with knowledge of the SCAD location, and a second blinded. Assessment of dissection healing were made and optimal timing of CTCA was also calculated.

RESULTS

A total of 32 patients with 38 non-contiguous SCAD lesions were included (mean age 50.5 ± 8.8 years, 65.6% women). The left circumflex artery was the most commonly affected vessel (34.2%), and 71.1% of lesions occurred in distal or branch vessels. Median time that CTCA was performed was 40.5 days from the index event, and 25 of 38 lesions had healed (65.8%). On blinded reporting, the sensitivity and specificity of CTCA for assessment of dissection healing was 72% and 53.8%, respectively. The optimal timing of CTCA to assess healing was 80 days (AUC 0.774, p=0.006; sensitivity 76.9%, specificity 84.0%). When early CTCA was performed (<80 days), 21 of 24 lesions (87.5%) were unhealed, whereas late CTCA (≥80 days) showed healing in 10 of 14 lesions (71.4%).

CONCLUSION

The usefulness of CTCA in diagnosing SCAD remains challenging due to limitations in spatial and temporal resolution, particularly in distal vessels. The optimal timing of CTCA to assess dissection healing was 80 days.

Type of Stressor and Medium-Term Outcomes After Takotsubo Syndrome: What Becomes of the Broken Hearted? (ANZACS-QI 59)

BACKGROUND

Takotsubo syndrome (TS) is often triggered by an acute physical or emotional stressor. We hypothesised that medium-term prognosis may be better for TS patients with an associated emotional stressor than for those with an acute physical illness.

METHODS

We identified consecutive TS patients presenting in New Zealand (2006-2018). The clinical presentation and outcomes of TS patients according to types of stressor (physical, emotional or no stressor) were assessed. Post-discharge survival after TS was compared with age- and gender-matched patients after myocardial infarction (MI) and people in the community without known cardiovascular disease (CVD).

RESULTS

Of 632 TS patients (95.9% women, mean age 65.0±11.1 years), 27.4% had an associated acute physical stressor, 46.4% an emotional stressor and 26.2% no evident stressor. In-hospital mortality was similar for each group (1.7%, 1.2%, 0.3% respectively, p=0.29). In a median 4.4 years post-discharge there were 54 deaths (53 non-cardiac). Compared with patients without known CVD, TS patients with physical stress and those with MI were less likely to survive (HR 4.46, 95%CI 3.10-6.42; HR 4.23, 95%CI 3.81-4.70 respectively) but survival for TS patients associated with emotional stress or no stressor was similar (HR 1.11, 95%CI 0.66-1.85; HR 1.08, 95%CI 0.54-2.18, respectively). Recurrence was similar among the three groups (p=0.14).

CONCLUSION

Takotsubo syndrome associated with physical stressor has a post-discharge mortality risk as high as after MI. In contrast, prognosis for TS triggered by an emotional stressor is excellent, and similar to that of those without known CVD.

Impact of COVID-19 Pandemic on Cardiovascular Testing in Asia

Background

The coronavirus disease-2019 (COVID-19) pandemic significantly affected management of cardiovascular disease around the world. The effect of the pandemic on volume of cardiovascular diagnostic procedures is not known.

Objectives

This study sought to evaluate the effects of the early phase of the COVID-19 pandemic on cardiovascular diagnostic procedures and safety practices in Asia.

Methods

The International Atomic Energy Agency conducted a worldwide survey to assess changes in cardiovascular procedure volume and safety practices caused by COVID-19. Testing volumes were reported for March 2020 and April 2020 and were compared to those from March 2019. Data from 180 centers across 33 Asian countries were grouped into 4 subregions for comparison.

Results

Procedure volumes decreased by 47% from March 2019 to March 2020, showing recovery from March 2020 to April 2020 in Eastern Asia, particularly in China. The majority of centers cancelled outpatient activities and increased time per study. Practice changes included implementing physical distancing and restricting visitors. Although COVID testing was not commonly performed, it was conducted in one-third of facilities in Eastern Asia. The most severe reductions in procedure volumes were observed in lower-income countries, where volumes decreased 81% from March 2019 to April 2020.

Conclusions

The COVID-19 pandemic in Asia caused significant reductions in cardiovascular diagnostic procedures, particularly in low-income countries. Further studies on effects of COVID-19 on cardiovascular outcomes and changes in care delivery are warranted.

A Decade of Transcatheter Aortic Valve Implantation in New Zealand: Growth and Inequalities

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is an effective treatment increasingly performed for severe aortic stenosis. Developing nationwide accessibility to TAVI can be met with barriers that result in treatment disparities.

OBJECTIVES

This nationwide retrospective study aimed to review the first decade of TAVI in New Zealand and identify potential inequalities.

METHODS

All patients undergoing TAVI in a New Zealand public hospital between 2008 and 2018 were included. Demographic and geographic details were analysed and TAVI rates were age standardised using census data. One-year survival was compared between groups.

RESULTS

A total of 952 patients were included in our study. The mean age was 80.0±7.5 years and women accounted for nearly half of all patients (42.5%). The age-standardised TAVI rate in New Zealand increased from 15 per million in 2013 to 49 per million in 2018. Since 2013, there has been a disproportionate growth in TAVI rates between different ethnicities. TAVI rates for Europeans grew from 16 to 66 per million compared to 7 to 8 per million for Pacific people and 3 to 5 per million for Maori. Despite nationwide access to TAVI in 2018, significant geographic heterogeneity remains, ranging from 2.0 to 12.8 procedures per 100,000 people between regions. One-year (1-yr) survival for Maori were significantly worse than Europeans (80.1% vs 93.9%, HR 4.2, 95%CI: 1.6-11.5, p=0.004) despite being younger (67.9 vs 80.6 years, p<0.05).

CONCLUSION

There are significant geographical and ethnic variations in TAVI rates in New Zealand. Maori had worse one-year survival than European patients following TAVI.

A comparison of the clinical features and outcomes of Takotsubo syndrome across five metropolitan hospitals in New Zealand

AIM

Takotsubo syndrome (TS) mimics acute coronary syndrome but has a distinct pathophysiology. This study aimed to compare and contrast the clinical presentation, management and outcomes of patients with TS in five large New Zealand hospitals.

METHODS

We identified 632 consecutive patients presenting to the five major tertiary hospitals in New Zealand (Middlemore Hospital, Auckland City Hospital, North Shore Hospital, Christchurch Hospital and Dunedin Hospital) between January 2006 and June 2018 and obtained clinical, laboratory, electrocardiography, echocardiography, coronary angiography and long-term follow-up data.

RESULTS

Six hundred and thirty-two consecutive patients with TS (606 women, mean age 65.0+11.1 years) were included. An associated stressor was identified in two-thirds of patients, and emotional triggers were more frequent than physical triggers (62.9% and 37.1%, respectively). Overall, 12.7% of patient had depression and 11.7% anxiety but this was more common in patients from Christchurch Hospital (20.4% and 23.4%, respectively). The in-hospital mortality among the five hospitals ranges between 0 to 2.0%. The mean follow-up was 4.9+3.4 years (median 4.4 years). Fifty-four people died post-discharge, all but one from a non-cardiac cause. Forty patients had recurrent TS. Mortality post-discharge (p=0.63) and TS recurrence (p=0.38) did not differ significantly among the five hospitals.

CONCLUSION

In this large New Zealand TS cohort, the clinical characteristics and presentation were similar among the five hospitals. A subset of patients had a complicated in-hospital course, but late deaths were almost all from non-cardiac causes and recurrence was infrequent. Mortality post-discharge and recurrence was similar between the hospitals.

CSANZ Imaging Council Position Statement on Echocardiography Services During the COVID-19 Pandemic

This Cardiac Society of Australia and New Zealand (CSANZ) Imaging Council Position Statement aims to guide local, regional and national clinical practice, and facilitate resource and echocardiographic service planning appropriately during the current COVID-19 global pandemic. General considerations include workforce arrangements and contingency plans, patient risk assessment for COVID-19 and level of care (personal protective equipment) for staff. Both outpatient and inpatient settings are addressed, including specific considerations in the in-patient setting including scanning protocols, screening modalities and indications for echocardiograms in the context of COVID-19 infection.

A Score to differentiate Takotsubo syndrome from non-ST-elevation myocardial nfarction in women at the bedside

Objective

A score to distinguish Takotsubo syndrome (TS) from acute coronary syndrome would be useful to facilitate appropriate patient investigation and management. This study sought to derive and validate a simple score using demographic, clinical and ECG data to distinguish women with non-ST elevation myocardial infarction (NSTEMI) from NSTE-TS.

Methods

The derivation cohort consisted of women with NSTE-TS (n=100) and NSTEMI (n=100). Logistic regression was used to derive the score using ECG values available on the postacute ward round on day 1 post-hospital admission. The score was then temporally validated in subsequent consecutive patients with NSTE-TS (n=40) and NSTEMI (n=70).

Results

The five variables in the score and their relative weights were: T-wave inversion in ≥6 leads (+3), recent stress (+2), diabetes (−1), prior cardiovascular disease (−2) and ST-depression in any lead (−3). When calculated using ECG values obtained at admission, discrimination between conditions was very good (area under the curve (AUC) 0.87 95% CI 0.83 to 0.92). The optimal score cut-point of ≥1 to predict NSTE-TS had 73% sensitivity and 90% specificity. When applied to the validation cohort at admission, AUC was 0.82 (95% CI 0.75 to 0.90) and positive and negative predictive values were 78% and 81%, respectively. On day 1 post-admission, AUC was 0.92 (95% CI 0.87 to 0.97), with positive and negative predictive values of 77% and 91%, respectively.

Conclusion

This NSTE-TS score is easy to use and may prove useful in clinical practice to distinguish women with NSTE-TS from NSTEMI. Further validation in external cohorts is needed.

Design of a Long-Acting and Selective MEG-Fatty Acid Stapled Prolactin-Releasing Peptide Analog

Anorexigenic peptides offer promise as potential therapies targeting the escalating global obesity epidemic. Prolactin-releasing peptide (PrRP), a novel member of the RFamide family secreted by the hypothalamus, shows therapeutic potential by decreasing food intake and body weight in rodent models via GPR10 activation. Here we describe the design of a long-acting PrRP using our recently developed novel multiple ethylene glycol-fatty acid (MEG-FA) stapling platform. By incorporating serum albumin binding fatty acids onto a covalent side chain staple, we have generated a series of MEG-FA stapled PrRP analogs with enhanced serum stability and in vivo half-life. Our lead compound 18-S4 exhibits good in vitro potency and selectivity against GPR10, improved serum stability, and extended in vivo half-life (7.8 h) in mouse. Furthermore, 18-S4 demonstrates a potent body weight reduction effect in a diet-induced obesity (DIO) mouse model, representing a promising long-acting PrRP analog for further evaluation in the chronic obesity setting.

Dual Mechanism of Methamphetamine-induced Cardiomyopathy on Magnetic Resonance Imaging

Methamphetamine is associated with a number of adverse cardiovascular effects and diseases. We present a case of a 50 year old male presenting with heart failure and angina and long-standing methamphetamine use. With the aid of cardiac magnetic resonance imaging and also coronary angiography, we speculated the dual pathophysiology of methamphetamine-induced cardiomyopathy in this patient.

Prognostic Value of Global Longitudinal Strain in Hypertrophic Cardiomyopathy: A Systematic Review of Existing Literature

OBJECTIVES

The association of left ventricular global longitudinal strain (LV-GLS) with clinical outcomes in patients with hypertrophic cardiomyopathy (HCM) has been examined in multiple studies. The authors conducted a systematic review aimed at summarizing and critically appraising the current evidence.

BACKGROUND

HCM is a common genetic cardiovascular disease with an estimated prevalence of 1 in 500 patients. LV-GLS derived from speckle tracking echocardiography is a sensitive noninvasive method of assessing regional left ventricular function. Several studies have suggested association of abnormal LV-GLS with outcomes in HCM patients.

METHODS

A computerized literature search of all English language publications in the PubMed and EMBASE databases was made looking at all randomized and nonrandomized studies conducted on patients with HCM where association of LV-GLS with clinical outcomes was studied. We then manually searched the reference lists of included articles. The Preferred Reporting Items for Systematic reviews and Meta-Analyses statement (PRISMA) of reporting systematic reviews was used.

RESULTS

Our search yielded a total of 14 observational studies published between 2009 and 2017 with a total of 3,154 patients with HCM. Eleven of the 14 studies included a composite cardiac outcome which included mortality as their primary outcome of interest and 3 of the 14 studies looked at association of LV-GLS with ventricular arrhythmias and/or implantable cardiac defibrillator discharge. We noted wide variability in inclusion, methodology, follow-up, and consequently effect estimates, which was not conducive to performing a meta-analysis. However, despite the variation, all studies revealed a degree of association of abnormal LV-GLS with poor cardiac outcomes.

CONCLUSIONS

Our systematic review of more than 3000 HCM patients suggests an association of abnormal LV-GLS with adverse composite cardiac outcomes and ventricular arrhythmias.

A novel inhibitor of inducible NOS dimerization protects against cytokine-induced rat beta cell dysfunction

BACKGROUND AND PURPOSE

Beta cell apoptosis is a major feature of type 1 diabetes, and pro-inflammatory cytokines are key drivers of the deterioration of beta cell mass through induction of apoptosis. Mitochondrial stress plays a critical role in mediating apoptosis by releasing cytochrome C into the cytoplasm, directly activating caspase-9 and its downstream signalling cascade. We aimed to identify new compounds that protect beta cells from cytokine-induced activation of the intrinsic (mitochondrial) pathway of apoptosis.

EXPERIMENTAL APPROACH

Diabetogenic media, composed of IL-1β, IFN-γ and high glucose, were used to induce mitochondrial stress in rat insulin-producing INS1E cells, and a high-content image-based screen of small molecule modulators of Casp9 pathway was performed.

KEY RESULTS

A novel small molecule, ATV399, was identified from a high-content image-based screen for compounds that inhibit cleaved caspase-9 activation and subsequent beta cell apoptosis induced by a combination of IL-1β, IFN-γ and high glucose, which together mimic the pathogenic diabetic milieu. Through medicinal chemistry optimization, potency was markedly improved (6-30 fold), with reduced inhibitory effects on CYP3A4. Improved analogues, such as CAT639, improved beta cell viability and insulin secretion in cytokine-treated rat insulin-producing INS1E cells and primary dispersed islet cells. Mechanistically, CAT639 reduced the production of NO by allosterically inhibiting dimerization of inducible NOS (iNOS) without affecting its mRNA levels.

CONCLUSION AND IMPLICATIONS

Taken together, these studies demonstrate a successful phenotypic screening campaign resulting in identification of an inhibitor of iNOS dimerization that protects beta cell viability and function through modulation of mitochondrial stress induced by cytokines.

The value of CT cardiac angiography and CT calcium score testing in a modern cardiology service in New Zealand: a report of a single centre eight-year experience from 5,237 outpatient procedures

BACKGROUND

Computed tomographic (CT) cardiac angiography is of increasing value in several areas of patient management in cardiology. We assessed the ability of CT cardiac angiography to effectively 'rule out' severe coronary stenoses in patients presenting with 'atypical' symptoms and/or an equivocal stress test, which offers a new approach to the management of coronary artery disease. We also examined the use of the CT calcium score test in cardiovascular (CVS) risk assessment.

METHODS

From a large single centre (Mercy Hospital) in Auckland, using a prospectively acquired, comprehensive database, we audited the entire eight-year experience of 5,169 patients (7/8/06 to 31/1/14) who underwent 5,237 64-slice computed tomographic (CT) cardiac angiogram or CT calcium score tests (GE Lightspeed scanner).

RESULTS

From 5,169 patients there were 5,237 CT procedures. The mean patient age was 57 (SD 10) years; 42% patients were female. Of the 3,603 (69%) full CT cardiac angiogram scans, 3,509 (67%) included a calcium score test. One thousand four hundred and eighty-three (28%) of scans were a calcium score test only. Of the 3,603 (69%) full CT cardiac angiogram scans, it was possible to 'rule out' significant coronary atheroma (stenosis ≥50%) in 2,947 (82%) of these procedures. Of the 4,903 (94%) patients who had a CT calcium score test, in whom we could calculate the NZ Framingham-based CVS risk, it was possible to reassign 532 (22%) of these patients who were previously thought to be at 'low risk' to be at a higher CVS risk.

CONCLUSION

CT cardiac angiography has become established in the modern management of cardiology patients. It has particular value as a tool to 'rule out' severe coronary stenoses, and as a tool to give a more accurate assessment of CVS risk. It adds significant value to the care of many patients within an established cardiology practice.

Advanced Electrocardiography Identifies Left Ventricular Systolic Dysfunction in Non-Ischemic Cardiomyopathy and Tracks Serial Change over Time

Electrocardiogram (ECG)-based detection of left ventricular systolic dysfunction (LVSD) has poor specificity and positive predictive value, even when including major ECG abnormalities, such as left bundle branch block (LBBB) within the criteria for diagnosis. Although machine-read ECG algorithms do not provide information on LVSD, advanced ECG (A-ECG), using multiparameter scores, has superior diagnostic utility to strictly conventional ECG for identifying various cardiac pathologies, including LVSD. Methods: We evaluated the diagnostic utility of A-ECG in a case-control study of 40 patients with LVSD (LV ejection fraction < 50% by echocardiography), due to non-ischemic cardiomyopathy (NICM), and 39 other patients without LVSD. Diagnostic sensitivity and specificity for LVSD were determined after applying a previously validated probabilistic A-ECG score for LVSD to stored standard (10 s) clinical 12L ECGs. In 25 of the NICM patients who had serial ECGs and echocardiograms, changes in the A-ECG score versus in echocardiographic LV ejection fraction were also studied to determine the level of agreement between the two tests. Results: Analyses by A-ECG had a sensitivity of 95% for LVSD (93% if excluding N = 11 patients with LBBB) and specificity of 95%. In the 29 NICM patients without LBBB who had serial ECGs, sensitivity improved to 97% when all ECGs were considered. By comparison, human readers in a busy clinical environment had a sensitivity of 90% and specificity of 63%. A-ECG score trajectories demonstrated improvement, deterioration or no change in LVSD, which agreed with echocardiography, in 76% of cases (n = 25). Conclusion: A-ECG scoring detects LVSD due to NICM with high sensitivity and specificity. Serial A-ECG score trajectories also represent a method for inexpensively demonstrating changes in LVSD. A-ECG scoring may be of particular value in areas where echocardiography is unavailable, or as a gatekeeper for echocardiography.

The beta3A subunit gene (Ap3b1) of the AP-3 adaptor complex is altered in the mouse hypopigmentation mutant pearl, a model for Hermansky-Pudlak syndrome and night blindness

Lysosomes, melanosomes and platelet-dense granules are abnormal in the mouse hypopigmentation mutant pearl. The beta3A subunit of the AP-3 adaptor complex, which likely regulates protein trafficking in the trans - Golgi network/endosomal compartments, was identified as a candidate for the pearl gene by a positional/candidate cloning approach. Mutations, including a large internal tandem duplication and a deletion, were identified in two respective pearl alleles and are predicted to abrogate function of the beta3A protein. Significantly lowered expression of altered beta3A transcripts occurred in kidney of both mutant alleles. The several distinct pearl phenotypes suggest novel functions for the AP-3 complex in mammals. These experiments also suggest mutations in AP-3 subunits as a basis for unique forms of human Hermansky-Pudlak syndrome and congenital night blindness, for which the pearl mouse is an appropriate animal model.