Carabello B. Modern Management of Mitral Stenosis. Circulation. 2005;112(3):432–437.
https://www.ahajournals.org/doi/10.1161/CIRCULATIONAHA.104.532498
25. Answer: D
Polyunsaturated fatty acids (PUFAs), such as omega‐3 and omega‐6 fatty acids, have multiple roles in membrane structure, lipid metabolism, coagulation, blood pressure, and inflammation. It has been suggested that regular supplementation of omega‐3 fatty acids is linked to a reduction in cardiovascular disease and other beneficial effects.
According to a recent Cochrane review, increasing PUFA intake may slightly reduce the risk of cardiovascular events but has no effect on all‐cause or cardiovascular disease mortality based on an extensive systematic review of RCTs conducted to date. The number need to treat to prevent one cardiovascular event is 63. The mechanism may be via serum triglycerides reduction.
Omega‐3 PUFA supplementation in type 2 diabetes lowers triglycerides and VLDL cholesterol, but may raise LDL cholesterol (although results were nonsignificant in subgroups) and has no statistically significant effect on glycaemic control or fasting insulin levels.
Omega‐3 fatty acids appear to have limited benefit in blood viscosity reduction in patients with intermittent claudication. However, there is no evidence of consistent improved clinical outcomes including quality of life, walking distance, ankle brachial pressure index, or angiographic findings. Supplementation may also cause adverse effects such as increased total and LDL cholesterol levels.
Direct evidence on the effect of omega‐3 PUFA on incident dementia is lacking. The available trials showed no benefit of omega‐3 PUFA supplementation on cognitive function in cognitively healthy older people.
Abdelhamid A, Martin N, Bridges C, et al. Polyunsaturated fatty acids for the primary and secondary prevention of cardiovascular disease. Cochrane Database of Systematic Reviews. 2018.
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD012345.pub3/full
26. Answer: D
Treatment resistant hypertension is defined as persistent hypertension despite adherent and optimal therapy with three different classes of antihypertensive medication including a diuretic, or any four agents. Cardiovascular and renal risk for such patients is two‐ to six fold higher than for patients with controlled hypertension. Medication compliance is an important factor in evaluating this patient. In addition to screening for secondary causes, which should be guided by history, examination, and laboratory findings, guidelines now suggest addition of a mineralocorticoid receptor antagonist (MRA) for this patient group. This is a result of multiple studies showing significant benefit for MRAs in this patient population. It is suggested that this may be due to high levels of undiagnosed hyperaldosteronism, but the benefits of MRA therapy, while predicted by presence of hyperaldosteronism, are not limited to this sub‐population, and suggests of resistant hypertension is often indicative of a salt‐retaining state.
Carey M, Whelton PK. Prevention, detection, evaluation and management of high blood pressure in adults: Synopsis of the 2017 American College of Cardiology/American Heart Association hypertension guideline. Ann Intern Med. 2018;168(5):351–8.
https://www.acc.org/˜/media/Non-Clinical/Files-PDFs-Excel-MS-Word-etc/Guidelines/2017/Guidelines_Made_Simple_2017_HBP.pdf
27. Answer: C
Restrictive cardiomyopathy (RCM) is a heterogeneous group of diseases with variable pathogenesis, clinical features, diagnostic criteria, management strategies and prognosis. It is the least common of the cardiomyopathies and is often underdiagnosed.
In patients with RCM, a restrictive ventricular filling pattern is noted secondary to ventricular stiffness. Biventricular size and normal or near‐normal ventricular systolic function are usual in the early stages of the disease. Depending on the ventricle involved, patients may have signs of right or left heart failure, conduction disturbance or arrhythmias. Diagnosis of RCM is based on echocardiogram, cardiac MRI and in some cases endomyocardial biopsy.
RCM is categorised as infiltrative (amyloidosis, sarcoidosis, primary hyperoxaluria), storage disease (Fabry disease, Gaucher disease, hereditary haemochromatosis, glycogen storage disease, mucopolysaccharidosis type I and type II, Niemann‐Pick disease), noninfiltrative (idiopathic, diabetic, scleroderma, myofibrillar myopathies, pseuxanthoma elasticum, sarcomeric protein disorders, Werner's syndrome), and endomyocardial (carcinoid heart disease, endomyocardial fibrosis including idiopathic, hypereosinophilic syndrome, chronic eosinophilic leukaemia, drug‐induced secondary to serotonin, methysergide, ergotamine, mercurial agents, busulfan, anthracyclines), endocardial fibroelastosis, metastatic cancer, and radiation, etc.
Left ventricular outflow tract obstruction is often seen in patients with subaortic stenosis, bicuspid aortic valve, supravalvular aortic stenosis, coarctation of the aorta, and hypertrophic cardiomyopathy. Option C is often seen in patients with sarcoidosis and RCM. Option D is seen in patients with dilated cardiomyopathy, which is the most common cause of cardiomyopathy.
Treatment should be of the underlying cause(s) of RCM if possible. Diuretics should be used with caution for patients with fluid overload, as some patients with RCM rely on high filling pressure to maintain cardiac output. Excessive diuresis may cause reduced cardiac tissue perfusion. β‐blockers and calcium channel blockers could be used to manage arrhythmias or increase filling time. However, careful monitoring of the response is required as some patients may be intolerant. Angiotensin‐converting enzyme (ACE) inhibitors and angiotensin receptor blockers should be considered. However, currently there is no evidence that these agents may be beneficial, and they may not be well tolerated by patients with RCM. Anticoagulation is required in patients with atrial fibrillation, mural thrombus, or evidence of systemic embolisation to prevent strokes. Left ventricular assist device may be beneficial in patients with advanced heart failure as a definitive therapy or as a bridge to cardiac transplant.
Muchtar E, Blauwet L, Gertz M. Restrictive Cardiomyopathy: Genetics, Pathogenesis, Clinical Manifestations, Diagnosis, and Therapy. Circulation Research. 2017;121(7):819–837.
https://www.ncbi.nlm.nih.gov/pubmed/28912185
28. Answer: D
Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) remain a significant cause of cardiovascular morbidity and mortality worldwide. In Australia, ARF and RHD disproportionately affect the ATSI population, with up to ×10 higher incidence, ×8 higher ARF hospitalisation rates, and ×20 higher mortality. The highest rates of ARF are in children aged 5–14 years old, and highest rates of RHD in adults aged 35–39, with an all‐age RHD incidence up to 2% in ATSI populations in the Northern Territory.
All patients with suspected ARF should be hospitalised to enable appropriate diagnostic investigations including echocardiogram. In high risk groups there should be a lower threshold for diagnosis as listed below and high‐risk groups are populations with an incidence of ARF >30/100 000 per year in 5–14 years old or incidence of RHD >2/1000 in all age groups.