Chi-Ming Chow

Vascular endothelial function in cyclosporine and tacrolimus treated renal transplant recipients.

BACKGROUND Endothelial dysfunction is an early key event in the development of arteriosclerotic cardiovascular disease (ASCVD), thus an early marker of subclinical ASCVD. Endothelial function is impaired in renal transplant recipients (RTR) treated with cyclosporine (CyA). Tacrolimus is associated with less hyperlipidemia and hypertension than CyA, however, there are no data on endothelial function in tacrolimus-treated RTR. METHODS High-resolution brachial ultrasonography was used to assess endothelium-dependent dilatation (EDD), and endothelium-independent dilatation (EID) in 20 stable RTR and a control group of 10 healthy subjects without clinical evidence of ASCVD. The RTR group included patients receiving CyA (n=10) and tacrolimus (n=10). EDD and EID were measured as percent increase in brachial artery diameter in response to reactive hyperemia and nitroglycerin, respectively. RESULTS AND CONCLUSIONS EDD was significantly lower in RTR versus controls (1.7+/-0.7 vs. 7.3+/-0.7%, P<0.0001), whereas EID was similar in the two groups. No significant differences were found in EDD or in EID between CyA- and tacrolimus-treated RTR. Glomerular filtration rate, plasma homocysteine, blood pressure, and lipid profiles were similar in CyA- and tacrolimus-treated RTR.

Lack of awareness of heart disease and stroke among Chinese Canadians: Results of a pilot study of the Chinese Canadian Cardiovascular Health Project

BACKGROUND According to Statistics Canadas 2001 census, the Chinese make up the largest (27.5%) visible minority population in Canada. The cardiovascular health information for this population is therefore important for the allocation of health care and promotion resources. OBJECTIVES In the present pilot study, the authors sought to define the degree of awareness and knowledge of cardiovascular disease, as well as their risk factors, among the Chinese Canadian population. METHODS A 16-item telephone survey was conducted among 1004 ethnic Chinese subjects (18 years of age and older) in the greater Toronto area of Ontario (n=503) and the greater Vancouver area of British Columbia (n=501) in February 2004. RESULTS Among the respondents, 73% spoke Cantonese at home and 21% spoke Mandarin. Ninety-seven per cent were immigrants, and 53% had been in Canada for less than 10 years. A history of hypertension was reported in 9.2% of respondents, diabetes in 3.2% and high cholesterol in 14.5%. Thirty-two per cent and 40% of respondents were unable to name at least one symptom of heart attack or stroke, respectively, unaided. Thirty-two per cent and 35% of respondents named at least one incorrect symptom of heart attack and stroke, respectively. When asked about their immediate response in a hypothetical case of a heart attack or stroke, only 20% would have called 911. CONCLUSIONS The present study is the first to address the awareness of cardiovascular health and disease among Chinese Canadians. These data suggest that Chinese Canadians have a relatively low awareness of the warning symptoms for common cardiovascular emergency situations. The findings presented here have important implications for the development of future health promotion and research initiatives targeted to visible minority populations in Canada.

Design and methods of the Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen SignificantlY) study: An investigator-blinded randomized controlled trial of education and feedback intervention to reduce inappropriate echocardiograms

BACKGROUND Appropriate use criteria (AUC) for transthoracic echocardiography (TTE) were developed to address concerns regarding inappropriate use of TTE. A previous pilot study suggests that an educational and feedback intervention can reduce inappropriate TTEs ordered by physicians in training. It is unknown if this type of intervention will be effective when targeted at attending level physicians in a variety of clinical settings. AIMS The aim of this international, multicenter study is to evaluate the hypothesis that an AUC-based educational and feedback intervention will reduce the proportion of inappropriate echocardiograms ordered by attending physicians in the ambulatory environment. METHODS In an ongoing multicentered, investigator-blinded, randomized controlled trial across Canada and the United States, cardiologists and primary care physicians practicing in the ambulatory setting will be enrolled. The intervention arm will receive (1) a lecture outlining the AUC and most recent available evidence highlighting appropriate use of TTE, (2) access to the American Society of Echocardiography mobile phone app, and (3) individualized feedback reports e-mailed monthly summarizing TTE ordering behavior including information on inappropriate TTEs and brief explanations of the inappropriate designation. The control group will receive no education on TTE appropriate use and order TTEs as usual practice. CONCLUSIONS The Echo WISELY (Will Inappropriate Scenarios for Echocardiography Lessen Significantly in an education RCT) study is the first multicenter randomized trial of an AUC-based educational intervention. The study will examine whether an education and feedback intervention will reduce the rate of outpatient inappropriate TTEs ordered by attending level cardiologists and primary care physicians (www.clinicaltrials.gov identifier NCT02038101).

An unusual case of chronic coronary artery dissection: Did cisplatin play a role?

Spontaneous coronary artery dissection is an unusual cause of acute myocardial ischemia. The natural history of spontaneous coronary artery dissection that persists on angiography after the acute event has not been well characterized. A case of a 36-year-old man who presented with monomorphic ventricular tachycardia 12 years following a myocardial infarction that occurred during his last course of bleomycin-etoposide-cisplatin therapy for testicular cancer is reported. On further investigation, coronary angiography revealed a long chronic dissection of the right coronary artery. The patient was successfully treated with medical management and insertion of an implantable cardioverter defibrillator. The case also highlights the increased cardiovascular morbidity in testicular cancer survivors and evokes the possibility of mechanisms of myocardial ischemia other than atherosclerotic disease in these young patients.

Surgical treatment for incessant pericarditis

A case of chronic relapsing pericarditis is presented in which all forms of medical therapy failed. Pericardectomy was performed as a last resort, with complete resolution of symptoms. Incessant pericarditis, as distinguished from recurrent intermittent pericarditis, may respond favourably to surgical removal, especially in the presence of recurrent pericardial effusion.

How many cardiovascular events can be prevented with optimal management of high-risk Canadians?

BACKGROUND Strong evidence exists to support the use of statins, acetylsalicylic acid (ASA) and angiotensin-converting enzyme inhibitors (ACEI) in patients at high risk of cardiovascular (CV) events; however, current practice pattern data indicate that a significant care gap exists between evidence and practice. OBJECTIVES To quantify the reduction in CV events that may be obtained with the optimal use of vascular protection therapy in Canadians at high risk of cardiovascular events. METHODS Canadian Community Health Survey data from 2003 were used to estimate the prevalence of heart disease and/or diabetes, which were applied to an age-specific population in Canada to calculate the total number of high-risk patients. The number of events over 10 years was estimated using a state transition model, published risk equations, practice pattern data from Canadian registries and published therapy efficacy from clinical trials. RESULTS Among 2.2 million high-risk Canadians, current care with statin, ASA and ACEI therapy has reduced the estimated occurrence of CV events over the next 10 years by approximately 400,000 from 1.01 million. Universal use of combination statin, ASA and ACEI therapy for high-risk patients, compared with current care, would prevent as many as 143,000 more CV events over the next 10 years. CONCLUSIONS Great advances in the management of CV disease have been made; however, CV disease remains a substantial burden to patients and to the Canadian health care system. Canadian physicians have the opportunity to further reduce this burden through optimal management of high-risk patients based on clinical guidelines.

Mitral and tricuspid valve papillary fibroelastomas: A rare cause of multiple intracardiac masses

A 55-year-old woman with no cardiac history presented with increasing shortness of breath on exertion, worsening cough and orthopnea for three weeks. A transthoracic echocardiogram identified two intracardiac masses. Transesophageal echocardiography demonstrated a 1.8 cm × 1.5 cm mass attached to the base of the posterior tricuspid leaflet (Figure 1A) and a 1.0 cm × 0.5 cm mass attached to the atrial side of the left mitral leaflet (Figure 1B). Both masses displayed indistinct surface features and neither was attached to the atrial wall or interatrial septum. No other intracardiac pathology was identified. The differential diagnosis included primary cardiac tumour, metastatic malignancy, thrombus or vegetation. After an extensive workup, the patient ultimately went on to have surgical excision of these masses. Surgical pathology confirmed the diagnosis: mitral and tricuspid valve cardiac papillary fibroelastomas (CPFs). Figure 1 CPFs are the second most common primary cardiac tumour in adults. They are benign avascular tumours made of papillary elastin fibrils in a hyaline stroma covered with a single layer of endothelium. These tumours occur most frequently on the aortic and mitral valves, and infrequently on the tricuspid and pulmonic valves. On echocardiography, CPFs are typically small, well-demarcated, highly mobile masses attached to the endocardium by a pedicle. They can have a highly refractive appearance, often with areas of echolucency and a ‘speckled’ appearance around the perimeter. Multiple CPFs are an exceedingly rare finding. While typically asymptomatic, CPFs can present with stroke, sudden death, myocardial infarction, heart failure, syncope, pulmonary embolism or peripheral infarction. To date, no recurrences of CPFs after surgical excision have been reported, and the long-term prognosis of these patients appears to be excellent (1–4).

Abdominal Aortic Occlusion Following Large Left Atrial Mass Embolization

Graphical abstract