Significance of Anti-Myosin Antibody Formation in Patients With Myocardial Infarction: A Prospective Observational Study.

BACKGROUND: Anti-myosin antibodies (AMAs) are often formed in response to myocardial infarction (MI) and have been implicated in maladaptive cardiac remodelling. We aimed to: (1) compare AMA formation in patients with Non-ST-Elevation MI (NSTEMI) and ST-Elevation MI (STEMI); (2) evaluate factors predicting autoantibody formation; and, (3) explore their functional significance. METHODS: Immunoglobulin M (IgM) and Immunoglobulin G (IgG) AMA titres were determined in serum samples collected at admission, 3 and 6 months post MI. The relationship between demographic and clinical data, and antibody formation, was investigated to determine factors predicting antibody formation and functional significance. RESULTS: Forty-three (43) patients were consecutively recruited; 74.4% were positive for IgM at admission, compared with 23.3% for IgG. Mean IgG levels increased by 1.24% (±0.28) at 3 months, and 13.55% (±0.13) at 6 months post MI. Mean antibody levels were significantly higher in the NSTEMI cohort at both follow-up time points for IgG (p<0.001, p<0.0001), but not IgM (p=0.910, p=0.066). A moderately positive correlation between infarct size and increase in mean IgM concentration was observed at 3 months (r(98)=0.455; p=0.015). Anti-myosin antibody formation was not associated with an unfavourable outcome at follow-up. CONCLUSIONS: Anti-myosin antibodies are formed in a significant proportion of patients following MI, particularly among those with NSTEMI. While IgM levels fall after infarction, IgG levels increase and persist beyond 6 months of follow-up. This raises the possibility that they may contribute to long-term myocardial damage and dysfunction. Future research should focus on the specific epitopes that are targeted by these antibodies, and their functional significance. This may result in the emergence of novel therapies to attenuate cardiac dysfunction in MI patients.

Acute compartment syndrome: A rare but important complication of transradial cardiac catheterization.

The transradial approach has become the gold-standard for coronary angiography. It is better tolerated by patients, associated with less bleeding, earlier post-procedure mobilization, and reduced mortality in patients with myocardial infarction. Given the hand's dual arterial supply and extensive collateral circulation, the risk of serious functional injury after radial catheterization is essentially reduced to zero. However, even a small amount of bleeding in the volar compartment can lead to compartment syndrome (CS) and permanent neurovascular injury. The purpose of this paper is to describe our experience with an unusual case of late-onset acute CS following transradial coronary angiography, and to summarize the available literature on this topic. .

Anti-troponin antibodies following myocardial infarction.

Recent improvements in medical and surgical coronary revascularization techniques have significantly improved outcomes for patients with acute myocardial infarction (MI). However, large infarctions are often followed by a poorly understood process of pathological ventricular remodelling, which fails to return the heart to its premorbid state. Although it remains incompletely understood, there is increasing interest in the role of the immune system in this process. One hypothesis is that released cardiac proteins become the focus of an immune response that results in the formation of functionally significant autoantibodies. This review summarizes the current literature, both human and animal, relating to the formation and clinical relevance of anti-troponin antibodies (ATAs) in patients with MI.

Heart of the tropics: delivering evidence-based care for acute coronary syndromes in northern Australia.

Acute coronary syndromes (ACS) are life-threatening medical emergencies that require urgent treatment, posing particular challenges for systems of health care in regional and remote parts of the world characterised by large distances and widely dispersed populations and healthcare facilities. Northern Australia is such an environment. The prevalence of cardiovascular risk factors, coronary artery disease and ACS (myocardial infarction and unstable angina) in northern Australia is amongst the highest in Australia. Despite the high burden of disease, appropriate healthcare services to address these important health challenges have been inadequate. The Australian Commission on Safety and Quality in Health Care has released a Clinical Care Standard for Acute Coronary Syndromes and the National Heart Foundation of Australia has developed an ACS Capabilities Framework, which together define minimum standards of care regardless of the patient's location. Strategies such as uniform state-wide ACS clinical pathways provide guidance on how evidence-based care can be provided in a range of geographical settings and to all populations, including Indigenous Australians. The continuing evolution of cardiac catheter laboratories in Townsville, Cairns, Mackay and Darwin has facilitated improved treatment for ACS in northern Australia, and has supported the development of region-wide, integrated, multidisciplinary pathways of care. Systems of care in ACS require consideration of the perspectives of the patient (from symptom onset to long-term secondary prevention of further events), the health system ('dissolving' traditional regional silos of care to enable a higher critical mass, greater cooperation, better communication and improved efficiency) and healthcare disciplines and services (including ambulance, retrieval, local health centres and local hospitals, tertiary centres, cardiac rehabilitation and general practice).

The role of anti-myosin antibodies in perpetuating cardiac damage following myocardial infarction.

Recent improvements in the medical and surgical management of myocardial infarction mean that many patients are now surviving with greater impairment of cardiac function. Despite appropriate management, some of these patients subsequently develop pathological ventricular remodelling, which compounds their contractile dysfunction and can lead to congestive cardiac failure (CCF). The pathophysiological mechanism underpinning this process remains incompletely understood. One hypothesis suggests that a post-infarction autoimmune response, directed against constituents of cardiac myocytes, including cardiac myosin, may make an important contribution. Our review summarises the current literature related to the formation and clinical relevance of anti-myosin antibodies (AMAs) in patients with myocardial infarction. This discussion is supplemented with reference to a number of important animal studies, which provide evidence of the potential mechanisms underlying AMA formation and autoantibody mediated cardiac dysfunction.

Practical experience with ticagrelor: an Australian and New Zealand perspective.

OBJECTIVE: Ticagrelor is recommended in local and international guidelines as first-line therapy in combination with aspirin in patients presenting with acute coronary syndromes (ACS). The purpose of this article is to provide practical guidance regarding the use of ticagrelor in this setting. METHODS AND RESULTS: Ticagrelor, a direct-acting, reversible P2Y12 receptor antagonist, has a faster onset, and a more potent and predictable antiplatelet effect compared with clopidogrel. The authors recommend considering the use of ticagrelor in moderate-to-high risk ACS patients treated with an invasive approach and those managed non-invasively who have elevated troponin levels. Consistent with outcomes observed in the PLATO trial overall, ticagrelor was superior to clopidogrel treatment in patients with chronic kidney disease, a history of stroke or transient ischemic attack, the elderly, and patients requiring surgical revascularization. CONCLUSIONS: When switching from clopidogrel to ticagrelor, patients established on clopidogrel therapy can be switched directly without loading; patients not loaded with clopidogrel and not taking maintenance dose clopidogrel for at least 5 days should first be loaded with ticagrelor. Guidelines recommend discontinuing ticagrelor 5 days before surgery if antiplatelet effects are not desired and recommencing therapy as soon as safe following surgery. Ticagrelor should be avoided in individuals with a history of intracranial hemorrhage, moderate-to-severe hepatic impairment, high bleeding risk, within 24 hours of thrombolytic therapy, and in those treated with oral anticoagulants. Local, real-world experience suggests low bleeding rates with ticagrelor therapy. Dyspnoea is a common symptom in patients with ACS and is also a side-effect of ticagrelor therapy. Discontinuation of ticagrelor due to dyspnoea has been uncommon in clinical trials. However, local registry data suggest higher discontinuation rates (2-9%) related to dyspnoea in the real-world setting, indicating that clinicians may need to consider other potential causes of dyspnoea before discontinuing ticagrelor.

Extreme hypertriglyceridemia managed with insulin.

Extreme hypertriglyceridemia can lead to acute pancreatitis and rapid lowering of serum triglycerides (TG) is necessary for preventing such life-threatening complications. However, there is no established consensus on the acute management of extreme hypertriglyceridemia. We retrospectively reviewed 10 cases of extreme hypertriglyceridemia with mean serum TG on presentation of 101.5 ± 23.4 mmol/L (8982 ± 2070 mg/dL) managed with insulin. Serum TG decreased by 87 ± 4% in 24 hours in those patients managed with intravenous insulin and fasting and 40 ± 8.4% in those managed with intravenous insulin alone (P = .0003). The clinical course was uncomplicated in all except 1 patient who subsequently developed a pancreatic pseudocyst. Thus, combination of intravenous insulin with fasting appears to be an effective, simple, and safe treatment strategy in immediate management of extreme hypertriglyceridemia.

Stent-graft repair of a giant saphenous vein graft aneurysm.

Saphenous vein graft aneurysms are an uncommon late complication of coronary artery bypass surgery (CABG). Management strategies include surgical revision, percutaneous closure using covered stent grafts, coil embolisation, vascular plug insertion and ethylene vinyl alcohol copolymer injection. We report a case of a very large saphenous vein graft aneurysm successfully treated with a covered stent graft.

Surgery Insight: percutaneous treatment of prosthetic paravalvular leaks.

Serious paravalvular leakage occurs in 1-5% of patients who have undergone surgical cardiac valve replacement procedures. Clinical manifestations include hemolysis, heart failure and arrhythmias. Presently, the gold standard treatment for severe paravalvular leakage is surgery; however, the outcomes remain far from optimum. In this Review we discuss the problem of paravalvular leak and focus on the role of percutaneous repair as a treatment option.

Long-term outcomes of percutaneous coronary intervention for unprotected left main coronary artery disease.

BACKGROUND: This study evaluates the in-hospital, 30 day and long-term results of stenting for unprotected left main coronary artery disease in our institution. METHODS: Between April 2001 and October 2005 all unprotected left main cases were retrospectively reviewed. Outcomes were obtained by case note review and postal questionnaire; primary care physicians were contacted to complete missing data. RESULTS: We identified 100 consecutive patients who underwent unprotected left main procedures, 1.44% of the institution PCI volume. Indications for a percutaneous strategy were non-surgical candidates (47), emergency revascularisation (25) and patient/physician preference (28). Overall procedural success was 97%. The majority of cases (n=78) were performed with a single-stent strategy. 55% received a drug-eluting stent. There were 7 in-hospital deaths, 5 in the emergency group (cardiogenic shock) and 2 non-CABG candidates. Post hospital discharge long-term clinical follow-up was 651+/-431 days (range 6-1741). There were 8 deaths post discharge. Patients presenting as an emergency had a 72% survival rate at long-term follow-up, non-surgical candidates 83%, and patient/physician preference group had a 100% long-term survival. Multivariate analysis revealed cardiogenic shock (HR=7.9, 95% CI 1.7-3.6, p=0.008), failed thrombolysis (HR=8.5, 95% CI 1.7-41.7, p=0.008) and use of a bare-metal stent (HR=4.4, 1.1-17.0, p=0.034) were independent predictors of mortality. CONCLUSIONS: Our data suggest that in contemporary practice stenting for unprotected left main disease can be considered as an alternative treatment to surgery for selected patients. The results of randomised controlled trials are awaited.

Percutaneous closure of an iatrogenic atrial septal defect.

We report the successful percutaneous closure of an iatrogenic atrial septal defect in a 71-year-old woman. The patient had undergone mitral valve replacement and coronary artery bypass grafting, followed by redo surgery to repair a para-valvular mitral leak. Post-operatively she remained significantly limited by dyspnoea. Repeat transoesophageal echocardiography documented a large iatrogenic atrial septal defect. The patient underwent percutaneous, trans-femoral closure of the defect using the Helex septal occluder (W.L. Gore, Newark, Delaware, USA) with dramatic clinical improvement.

Long term outcome of elective day case percutaneous coronary intervention in patients with stable angina.

Patients undergoing elective PCI are traditionally admitted overnight, however day case PCI cuts costs and has been proposed as a safe method for selected patients. We evaluated the success and long term clinical outcomes of day case percutaneous coronary intervention (PCI) for outpatients with stable angina. In total, 484 consecutive patients treated over a five year period with planned day case PCI were studied and followed up for 12 months. Successful PCI with same day discharge was performed in 463 patients (95.7%). There were 21 patients (4.3%) who required hospital admission. Reasons for failed discharge were hematoma formation (n=7, 1.4%), coronary dissection (n=4, 0.8%), post-procedural chest pain (n=3, 0.6%), prolonged procedure (n=2, 0.4%), and 1 each of acute stent thrombosis, coronary perforation, anaphylaxis, minor drug reaction and a functional study for untreated disease. One year follow up was complete for 439/484 (90.7%). At 12 months there were 6 hospitalizations for angina (1.2%, 95% CI 0.6-3.0%), 20 repeat revascularisations (4.1%, 95% CI 2.7-6.3%), 3 myocardial infarctions (0.6%, 95% CI 0.2-2.1%) and 2 deaths (0.4%, 95% CI 0.1-1.6%). Event free survival at 1 year follow up was 93.6% (95% CI 90.7-95.6%). Selecting patients for day case PCI is safe, and can achieve a high rate of success with excellent long term outcomes.

IVUS-guided evaluation and percutaneous intervention in an anomalous left main coronary artery.

We report the case of a 42-year-old female with proven anterior ischemia and an anomalous origin of the left main coronary artery (ALMCA) who underwent successful percutaneous coronary intervention (PCI) with intravascular ultrasound (IVUS) guidance. Angiographic and IVUS images demonstrate features unique to the ALMCA. The epidemiology, pathophysiology, evaluation and management options, including technical considerations for percutaneous intervention, are discussed. The ALMCA from the right sinus of Valsalva represents one of the few potentially serious congenital coronary artery anomalies. These patients are often young, have atypical presentation and carry a risk of sudden death. In combination with unfamiliar anatomy and pathophysiology, they pose serious diagnostic and therapeutic challenges. We present our experience in a patient who underwent successful PCI with IVUS guidance, and discuss the anatomy, pathophysiology, evaluation and treatment options for the ALMCA.

Percutaneous device closure of the patent foramen ovale during pregnancy.

OBJECTIVE: To review the procedures, results and follow-up of patients who underwent percutaneous device closure of a patent foramen ovale (PFO) during pregnancy. We report modifications made to the established technique that allowed absolute minimization of radiation exposure. Relevant management issues of this unusual presentation of cardiac disease in pregnancy are discussed. BACKGROUND: Stroke during or immediately prior to pregnancy is a catastrophic event. Paradoxical embolism may be more frequent due to the hypercoagulable state and increased incidence of venous thromboembolism. Treatment strategies must take into account the competing risks to mother and fetus. METHODS: Three patients, aged 34, 27, and 39, presented with ischemic neurological events during or immediately preceding pregnancy. Due to evidence of recurrent events or relative contraindication to anticoagulation they proceeded to percutaneous device closure during the second trimester. The Helex device (WL Gore and Associates) was used in all patients. Procedures were performed with local anesthesia under intra-cardiac echocardiography guidance. RESULTS: Successful closure was achieved with the Helex device in all three patients. Radiation doses, as assessed by dose area product, were 260, 58, and 19 cGy/cm(2), with estimated uterine (fetal) dose of <0.005 mGy, <0.001 mGy, and <0.0005 mGy. There were no peri-procedural complications. Despite one patient subsequently developing pre-eclampsia and another major post-partum hemorrhage all pregnancies were successful and free of further neurologic events. CONCLUSIONS: Percutaneous device closure of the PFO is a feasible option for selected patients with cryptogenic stroke believed secondary to paradoxical embolism. The procedure can be performed safely and effectively under local anesthesia using intra-cardiac echocardiography and with trivial fetal radiation exposure.

Anomalous circumflex artery: intravascular ultrasound imaging of dynamic compression and "two wire-two vessel" percutaneous intervention.

An anomalous origin of the left circumflex is the most common congenital abnormality encountered in coronary angiography and it may selectively predispose to focal accelerated atherosclerotic disease. We report the case of a 54-year-old man who presented with non-ST elevation myocardial infarction and a characteristic retroaortic (proximal) culprit lesion in his anomalous circumflex artery. Intravascular ultrasound images illustrate the dynamic nature of the lumen compression. A "two wires-two vessel" angioplasty technique provided extra support and is recommended to facilitate successful anomalous circumflex percutaneous coronary interventions.