The Australian New Zealand Spontaneous Coronary Artery Dissection (ANZ-SCAD) Registry - A Multi-Centre Cohort Study: Protocol, Background and Significance.

INTRODUCTION: Spontaneous coronary artery dissection (SCAD) is an under-recognised cause of acute coronary syndrome (ACS) with a strong female predominance. There are currently limited prospective studies and no randomised controlled trials that inform on SCAD's best clinical care. Little is also known about predictors of acute SCAD deterioration or recurrence. We describe the study design of a multi-centre prospective and historical cohort study recruiting patients with SCAD across 15-20 sites in Australia/New Zealand (NZ). The primary aim is to describe the clinical presentation, management and outcomes along with predictors of acute deterioration and recurrence in a large Australian/NZ SCAD cohort, with international data pooling. METHODS AND ANALYSIS: Consented patients diagnosed with SCAD during a hospital admission for an ACS will be prospectively followed at 30 days then yearly, for up to 5 years. Each recruiting site will also retrospectively identify historical cases of SCAD from the proceeding 10 years, with a waiver of consent. For historical cases, data will be collected in a de-identified manner with date of last follow-up or death obtained from the medical records. All cases undergo core laboratory adjudication of coronary angiography and any accompanying imaging to confirm SCAD diagnosis. The primary endpoint will be occurrence of major adverse cardiovascular events; a composite of all-cause mortality, recurrent myocardial infarction (including SCAD recurrence), stroke/transient ischaemic attack, heart failure, cardiogenic shock, cardiac arrest/ventricular arrhythmia, heart transplantation and, repeat/unplanned revascularisation. Secondary endpoints will include each individual primary outcome as well as acute SCAD extension and quality of life/Seattle Angina Score in prospectively recruited participants. Endpoints will be assessed at the end of the hospital admission and at 30-days, 1 year, and median long-term follow-up. ETHICS: Multicentre ethics approval has been granted from the Western Sydney Local Health District Human Research Ethics Committee (2021/ETH00040). DISSEMINATION OF RESULTS: The analysed results will be published in peer-reviewed journals on completion of the historical data collection and then on completion of the prospective data collection. REGISTRATION DETAILS: The ANZ-SCAD registry has been prospectively registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12621000824864).

Trends in the Detection, Management and 30-Day Outcomes of Spontaneous Coronary Artery Dissection: A Six-Year, New Zealand Centre Experience.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is an important but under-recognised cause of acute coronary syndrome (ACS), particularly in younger women. We assessed trends in the detection, management and outcomes of all patients with SCAD over 6 consecutive years. METHODS: All patients with first diagnosis of SCAD at Christchurch Public Hospital, New Zealand, between January 2014 and January 2020 were included. Patient management and outcomes were determined by retrospective review of medical records. SCAD presentations were compared to total ACS presentations, obtained from a national ACS (ANZACS-QI) database. RESULTS: We identified 113 patients with angiographic diagnosis of SCAD. Median age was 54 years (88% female). The detection of SCAD increased over the period, both as a total number (Kendall's τ 0.87, p=0.015) and as a proportion of all ACS (p value for trend <0.0001). In 2019, SCAD represented 2.4% of all ACS and 18% of ACS in females aged less than 60 years. The most common presentation was non-ST elevation myocardial infarction (NSTEMI) in 72%; and, there was an increase in NSTEMI compared with STEMI over the period (p=0.023). Initial strategy of percutaneous coronary intervention (PCI) was undertaken in 12% of patients, with a significant trend towards a more conservative approach over the study period (p=0.019). The rate of 30-day major adverse cardiovascular events (MACE) was 8.8% overall, and significantly reduced over the study period to 3% in 2019 (p value for trend, 0.006). CONCLUSIONS: The detection of SCAD has increased and is a particularly important cause of ACS in younger women. This increase has been largely driven by an increasing number of NSTEMI patients diagnosed with SCAD, associated with a significant improvement in 30-day MACE.

The Utility of Contrast Medium Fractional Flow Reserve in Functional Assessment Of Coronary Disease in Daily Practice.

BACKGROUND: Adenosine induced hyperaemic fractional flow reserve (aFFR) is a validated predictor of clinical outcome and part of routine interventional practice. Protocol issues associated with the adenosine infusion limit the use of aFFR in clinical practice. Contrast medium induced hyperaemic FFR (cFFR) is a simpler procedure from a practical standpoint. We compared the two in a real world setting. METHODS: We analysed 76 patients that had both cFFR and aFFR assessment of 100 angiographically indeterminate coronary stenosis. cFFR was performed with intracoronary contrast medium injections (10ml for left coronary lesions and 8ml for right coronary lesions). The diagnostic performance of cFFR was analysed and compared to the gold standard aFFR. RESULTS: Mean cFFR was 0.87 (±0.07) and mean aFFR was 0.84 (±0.08). Bland-Altman analysis revealed a close agreement between cFFR and aFFR (0.035±0.032; 95% CI: -0.028 to 0.098) and good linear correlation (r=0.92, r2=0.86; p<0.0001). Using cFFR cut-off values of ≤0.83 in predicting an aFFR value of ≤0.80 or a cFFR value ≥0.88, predicting an aFFR value of >0.80 yielded a sensitivity of 100%, specificity of 96.1%, positive predictive value of 92.3%, negative predictive value of 100% and diagnostic accuracy of 96%. Only 24% of cFFR values were in the 0.84 to 0.87 range. CONCLUSION: Contrast medium induced hyperaemic FFR as an initial assessment may limit the need for adenosine to when cFFR falls in the 0.84 to 0.87 range. The use of adenosine infusion potentially could have been avoided in the majority of patients in this study.

Effect of Ivabradine on Heart Rate and Duration of Exercise in Patients With Mild-to-Moderate Mitral Stenosis: A Randomized Comparison With Metoprolol.

BACKGROUND: Symptoms in mitral stenosis (MS) are heart rate (HR) dependent. Increase in HR reduces diastolic filling period with rise in transmitral gradient. By reducing HR, beta-blockers improve hemodynamics and relieve symptoms, but the use may be limited by side effects. The present randomized crossover study looked at comparative efficacy of ivabradine and metoprolol on symptoms, hemodynamics, and exercise parameters in patients with mild-to-moderate MS (mitral valve area, 1-2 cm) in normal sinus rhythm. MATERIAL AND METHODS: Baseline clinical assessment, treadmill stress testing, and an echocardiographic Doppler evaluation were performed to determine resting HR, total exercise duration, mean gradient across mitral valve, and mean pulmonary artery systolic pressure (PASP). Patients were then allocated to either metoprolol or ivabradine to maximal tolerated doses over 6 weeks (metoprolol: 100 mg twice a day, ivabradine: 10 mg twice a day). Reevaluation was done at the end of this period, and all drugs stopped for washout over 2 weeks. Thereafter, the 2 groups were crossed over to the other drug that was continued for another 6 weeks. Assessment was again performed at the end of this period. RESULTS: Thirty-three patients of 34 completed the protocol. Fifteen were male, mean age was 28.9 ± 6.6 years, all were in New York Heart Association class 2, and mean resting HR was 103.5 ± 7.2/min. Mean mitral valve area was 1.56 ± 0.16 cm, mean PASP was 38.1 ± 5.1 mm Hg, and mean gradient across mitral valve was 10.6 ± 1.6 mm Hg. Significant decrease in baseline and peak exercise HR was observed at the end of follow-up with both drugs. Reduction in mitral valve gradient after ivabradine (42%) and metoprolol (37%) and reduction in PASP after both ivabradine (23%) and metoprolol (27%) were to a similar extent. Significant reduction in total exercise duration after both ivabradine and metoprolol therapy was observed. One patient developed blurring of vision with ivabradine therapy but did not require discontinuation of drug. An improvement in dyspnea of one grade was observed in all the patients by treatment with both ivabradine and metoprolol. CONCLUSIONS: Both metoprolol and ivabradine reduced symptoms and improved hemodynamics significantly from baseline to a similar extent. Ivabradine thus can be used effectively and safely in patients with MS in normal sinus rhythm who are intolerant or contraindicated for beta-blocker therapy.

Outcomes in Patients Presenting with Symptoms Suggestive of Acute Coronary Syndrome with Elevated Cardiac Troponin but Non-obstructive Coronary Disease on Angiography.

BACKGROUND: Many patients provisionally diagnosed with acute myocardial infarction (AMI) have angiographically unobstructed coronary arteries. Despite other potential causes, patients are often diagnosed as AMI with psychosocial implications and medication burden. The aim of this audit was to review such patients at our centre. METHODS: All patients investigated for possible AMI with coronary angiography from 2007 until 2011 at Christchurch Hospital, New Zealand, in whom cardiac troponin was elevated (with no other cause found for that elevation) but coronary angiography showed diameter stenosis <50% were reviewed. Primary outcome was two-year cardiac death and AMI (by universal definition). RESULTS: Of the 351/6493 (5.4%) who met the inclusion criteria, 180 had normal angiograms and 171 had non-obstructive coronary disease (stenosis >0% and <50%). By two years there were two cardiac deaths (0.6%) and five AMIs (1.4%). The primary outcome rate was therefore 2.0% (2.2% for those with normal angiograms and 1.8% with non-flow limiting coronary disease, p=1.000). CONCLUSION: Patients who have presented with AMI symptoms, elevated cardiac troponin, and unobstructed coronary arteries on angiography are at very low risk of cardiac death (0.6%), AMI (1.4%) or either (2.0%) at two-year follow-up.

Comparative assessment of platelet GpIIb/IIIa receptor occupancy ratio with Eptifibatide/Tirofiban in patients presenting with ACS and undergoing PCI.

BACKGROUND: The level of platelet inhibition by a Glycoprotein IIb/IIIa (GpIIb/IIIa) antagonist therapy necessary to minimize thrombotic complications in patients undergoing percutaneous coronary intervention (PCI) is a subject of debate. The degree of platelet inhibition obtained 10 min after start of GpIIb/IIIa antagonist therapy predicts adverse events after PCI. The aim of this study was to look at platelet inhibition and to compare platelet GpIIb/IIIa receptors occupancy ratio (GpRO) with Eptifibatide and Tirofiban using various dose regimens and correlate with 30-day clinical outcomes in patients presenting with high-risk acute coronary syndromes (ACS) and undergoing PCI. METHODS: The patients were divided into four sub groups: (1) Eptifibatide two intracoronary bolus (180 µg/kg) alone (E(B)); or (2) two intravenous bolus (180 µg/kg) followed by infusion at 2 µg/kg/min for 24 h (E(B + Inf)); and (3) Tirofiban standard bolus dose (0.4 µg/kg) over 30 min followed by infusion at 0.1 µg/kg/min (T(Std)); or (4) at ADVANCE dose bolus (25 µg/kg) over 3 min, followed by infusion at 0.1 µg/kg/min (T(Adv)). Number of GpIIb/IIIa receptors was assessed by flow cytometry at baseline and 10 min after the bolus and percentage of free receptors was determined to calculate the GpRO. Patients were followed for 30 days for any major adverse cardiac events (MACE). RESULTS: 200 consecutive patients (including 74% with ST-elevation ACS) were enrolled. GpRO in groups E(B) (n = 48) and E(B + Inf) (n = 44) were 62.7% ± 27.2% and 61.4% ± 6.1% respectively while in the groups T(Std) (n = 96) and T(Adv) (n = 12) groups were 35.1% ± 17.74% and 68.8% ± 27.3% respectively. The GpRO was similar in E(B), E(B + Inf) and T(Adv) groups and was significantly higher than T(Std) group (p < 0.0001). The 30-day MACE rates in E(B) (4.2%), E(B + Inf) (4.5%) and T(Adv) (4.2%) were significantly lower than T(Std) group (12.5%) (p < 0.01). CONCLUSIONS: Standard dose Tirofiban results in significantly lower rates of GpIIb/IIIa receptor occupancy ratio and this correlated with higher incidence of 30-day MACE in high-risk ACS patients undergoing PCI.

Electrical disturbance in heart by smokeless tobacco.

Smokeless tobacco use in the form of chewed tobacco or snuff is common in various parts of the world, including India. It is well known that smokeless tobacco consumption is responsible for cancer but less is known about its role as a risk factor for cardiovascular disease. Nicotine, the main constituent of tobacco smoke is responsible for the elevated risk of the cardiovascular disease and sudden coronary death associated with smoking, presumably by provoking cardiac arrhythmias. This review discusses some of the acute and chronic cardiac effects of smokeless tobacco on cardiovascular disease with special reference to the electrical disturbance as well as comparing nicotine kinetics between smoking and smokeless tobacco. It would further enhance the clamor to urge people to quit all forms of tobacco consumption.

Use of implantable loop recorders to unravel the cause of unexplained syncope.

Syncope is a symptom of many underlying disease states, which range from the relatively benign to the life threatening. There are numerous investigations done for patients with recurrent unexplained syncope which may have very low yield when it comes to making a definitive diagnosis. Recently, the implantable loop recorder (ILR) for continuous monitoring of the cardiac rhythm has been launched in India. This review will briefly discuss these current available strategies and focus on the usefulness of an ILR in the definitive diagnosis and treatment of patients with a recurrent unexplained syncope.

Patients' perspective of quality-of-care and its correlation to quality-of-life following spontaneous coronary artery dissection.

AIM: Spontaneous coronary artery dissection (SCAD) is an under-recognised cause of myocardial infarction. We aimed to investigate SCAD survivors' perceptions of their quality-of-care and its relationship to quality-of-life. METHODS AND RESULTS: An anonymous survey was distributed online to SCAD survivors involved in Australian SCAD support groups, with 172 (95.3% female, mean age 52.6 ± 9.2 years) participants in the study. The survey involved assessment of quality-of-life using a standardised questionnaire (EQ-5DTM-3L). Respondents rated the quality-of-care received during their hospital admission for SCAD a median 8/10 [interquartile range (IQR) 7-10]. Respondents ≤50 years versus >50 years were more likely to perceive that their symptoms were not treated seriously as a myocardial infarction (χ2 = 4.127, df = 1, p < 0.05). Participants rated clinician's knowledge of SCAD a median 4/10 (IQR 2-8) and 7/10 (IQR 3-9) for Emergency and Cardiology clinicians, respectively (p < 0.05). The internet was the most selected source (45.4%) of useful SCAD information. The mean EQ-5DTM summary index was 0.79 (population norm 0.87). 47.2% of respondents reported a mental health condition diagnosis, with 36% of these diagnosed after their admission with SCAD. Quality-of-life was significantly associated with perceived quality-of-care: EQ-5DTM index/(1-EQ-5DTM index) increased by 13% for each unit increase in quality-of-care after adjusting for age and comorbidities (p < 0.001). CONCLUSION: While SCAD survivors rated their overall hospital care highly, healthcare providers' knowledge of SCAD was perceived to be poor and, the most common source of SCAD information was the internet. Mental health conditions were common, and a significant association was observed between perceived quality-of-care and SCAD survivors' quality-of-life.

Depression and the heart.

Cardio Vascular disease (CVD) as well as depression are both highly prevalent disorders and both of them cause a significant decrease in quality of life and increase the economic burden for the patient. Depressed individuals are more likely to develop angina, fatal or non-fatal myocardial infarction, than those who are not depressed. Over the past decade, evidence has accumulated to suggest that depression may be a risk factor for cardiac mortality in patients with established coronary artery disease (CAD). The 'vicious cycle' linking CVD to major depression and depression to CVD, deserves greater attention from both cardio-vascular and psychiatric investigators.(1).

Percutaneous balloon pericardiotomy for the treatment of recurrent malignant pericardial effusion.

Malignant disease with pericardial metastasis is one of the most common causes of recurrent pericardial effusion (PE) with tamponade. While surgical pericardiotomy in these patients is very morbid and may not be a viable option, a palliative treatment percutaneously with percutaneous balloon pericardiotomy (PBP) can be a preferred treatment. We report herewith a case of PBP technique done using our day-to-day catheterisation laboratory equipment.

Symptomatic complete heart block leading to a diagnosis of Kearns-Sayre syndrome.

Kearns-Sayre syndrome (KSS) is a rare syndrome characterized by the triad of progressive external ophthalmoplegia, pigmentary retinopathy and cardiac conduction system disturbances; it is a mitochondrial encephalomyopathy with which usually presents before the patient reaches the age of 20. Here we present a case report of a patient with KSS who presented with symptomatic complete heart block.

Giant right atrial aneurysm presenting as right heart failure.

Idiopathic aneurysmal dilatations of the right atrium are rare anomalies. We report one such case of a young man presenting with fatigue, abdominal distension, pedal oedema, unremarkable cardiac examination except for raised jugular venous pressure, an electrocardiogram showing normal sinus rhythm with right bundle-branch block, and an radiograph of the chest showing cardiomegaly. The echocardiographic examination revealed a giant right atrium with low pressure tricuspid regurgitation. The computed tomography confirmed the findings of two-dimensional echocardiography. He was put on medical treatment and remained symptomatically controlled on follow-up.

Calcified left atrial myxoma with osseous metaplasia.

An intracardiac myxoma is the most common tumour of the heart with an estimated incidence of 0.5 per million population per year. Extensive calcification is rare in these tumours. We describe a rare case of a large left atrial myxoma, visible on the chest radiograph, with extensive calcification and osseous metaplasia.

Mitral stenosis as a risk factor for embolic myocardial infarction--anticoagulation for some patients, individual treatment for all.

A 28 year-old lady with severe rheumatic mitral stenosis presented with non-ST-elevation myocardial infarction secondary to angiographically confirmed right coronary artery embolus with a likely source of mitral valve stenosis origin. This patient was successfully treated medically with dual anti-platelet and 72 hours of intravenous heparin, glycoprotein IIb/IIIa inhibitor and eptifibitide (Integrilin) with a repeated coronary angiogram showing complete resolution of embolus. The management of embolic myocardial infarction is discussed along with the risks of embolism in patients with mitral stenosis who remain in sinus rhythm.

Trifurcation stenting using two guide catheters.

Trifurcating coronary artery disease is a complex atherosclerotic process involving the origin of one or more of three side branches arising from a main trunk. The approach to treat trifurcation lesions has not been standardized. We describe a technique to percutaneously treat this lesion using routine day-to-day hardware and a unique two guide catheter technique.

Transradial simultaneous kissing stenting (SKS) with SheathLess access.

Transradial coronary intervention is usually performed via a 5 or 6 Fr sheath due to the small calibre of radial arteries. Simultaneous kissing stenting (SKS) technique requires a guiding catheter 7 Fr or larger and is therefore difficult to perform via transradial approach. Conversion to femoral approach or additional arterial access is usually required to achieve this goal. To overcome this limitation, a hydrophilic 7.5 Fr SheathLess guiding catheter can be exploited. This catheter possesses approximately the same size outer diameter as a 6 Fr sheath and an internal diameter of a 7.5 Fr catheter. A smooth and successful performance of SKS through transradial approach is described using this catheter.

Transcatheter aortic valve implantation complicated by acute structural valve failure requiring immediate valve in valve implantation.

The first percutaneous transcatheter aortic valve implantation (TAVI) was performed in 2002 by Alain Cribier with over 10,000 valve implants since. Despite this, as with all new technologies we remain on a learning curve and continue to encounter new challenges and complications. We report a case of acute structural valve failure treated successfully with a second valve in valve implantation of transcatheter aortic valve in a patient who had severe aortic stenosis (AS) complicated by a severely unfolded aorta.

Successful intravascular lithotripsy for severely calcified left anterior descending coronary artery stenosis.

Percutaneous coronary intervention (PCI) of heavily calcified stenoses remains a significant challenge to interventional cardiologists. Over the last years, high-pressure balloons, cutting balloons as well as atherectomy devices have been used to tackle such lesions. Lithoplasty is a method of lesion modification using intravascular lithotripsy (IVL, shockwave) to treat particularly calcified coronary lesions. A 55-year-old male without previous cardiac history reported chest pain and was found to have ECG changes anterolaterally and significantly elevated troponins. Coronary angiogram showed heavily calcified severe proximal left anterior descending (LAD) stenosis. The attempts to predilate the lesion with semi-compliant and non-compliant balloons at high pressures were unsuccessful so the decision was made to use a shockwave balloon. Subsequently a drug-eluting stent was successfully implanted and post-dilated at high pressure. Final angiography showed an excellent result, also confirmed in optical coherence tomography (OCT).