Cardiovascular disease in Chinese Canadians: a case-mix study from an urban tertiary care cardiology clinic.
BACKGROUND
Cardiovascular diseases (CVD) are the leading cause of death in Canada. Non-European ethnic groups such as the Chinese constitute an increasingly significant sector of the Canadian population.


OBJECTIVE
To compare the frequency and risk factors of CVD in Chinese and white Canadians in a cardiology referral clinic that saw a high number of ethnic Chinese patients and provided equal access to advanced diagnostic facilities.


PATIENTS AND METHODS
Clinic charts of patients referred between 1994 and 1999 were reviewed. Patients of Chinese descent were identified by their names. Primary cardiovascular and secondary cardiovascular diagnoses, as well as risk factors for coronary artery disease (CAD), were established. The frequency of disease and risk factors were age-standardized.


RESULTS
The sample of patients with CVD consisted of 404 Chinese and 1129 white subjects. Chinese patients were older (median age 65 versus 62 years, P=0.006). CAD, heart failure and peripheral vascular disease were less frequent in Chinese than in white patients. On the other hand, valvular heart disease was more frequent in Chinese patients. Diabetes, smoking and family history of heart disease were less frequent in Chinese subjects, whereas the frequencies of hypertension and hypercholerolemia were similar to those of white patients. In patients who had undergone coronary angiography, the frequency of multivessel CAD was less in Chinese patients (40% versus 56%, P=0.0016). Angina pectoris was a more common manifestation of CAD in Chinese patients, whereas myocardial infarction was more common in people who were white. In patients with heart failure, the median left ventricular ejection fraction was higher in Chinese than in white patients (34% versus 28%, P=0.031).


CONCLUSIONS
In patients referred to a cardiology clinic, the diagnosis of CAD and the majority of other CVDs was less frequent in Chinese Canadians than in white Canadians. However, selected modifiable risk factors for CAD, such as hypertension and hypercholesterolemia, were equally frequent. Further research at the population level is warranted to define the characteristics of CVD in Chinese Canadians, and may be useful to the future design of disease management and prevention programs tailored to the needs of this growing ethnic population.