With recent economic growth and changing life style, the incidence of coronary artery diseases in Korea has increased remarkably^1,2). This rather rapid increase has been at least partly attributed to westernized dietary habit, such as increased intake of animal fat as well as many other factors, including extended medical care through the medical insurance system.

Cardiovasular disease is the leading cause of mortality in Korea and increasing number of people in our country are expressing their concern about the coronary artery disease. However, there have been no systematic investigations whether or not the incidence is really increasing rapidly, what the pattern of coronary artery diseases in this country is and whether there is any difference in the prevalence and patterns compared to those in western countries.

Since little data are available, I would like to discuss the general features of coronary artery diseases in this country, especially in respect to the indicence, patterns including risk factors, clinical spectrum, changing diagnostic and therapeutic modalities and different aspects from those of western counries, based upon experiences of the Seoul National University Hospital during the past 10 years.

It is generally accepted that the number of coronary artery disease in Korea has been steadily increasing, though there hasn’t been any large-scale research on its actual prevalence. According to the data from Seoul National University Hospital, while the total number of admissions to the Internal Medicine Department in the year 1990 approximately doubled from that of 1979, the number due to acute myocardial infarction and angina increased 4 and 6.2 times respectively during the same period²⁾. Similar findings were also observed in the statistics of the Medical Insurance Corporation, suggesting that this trend is rather nationwide rather than confined to a certain hospital³⁾.

Although systematic investigations upon prevalence of risk factors and longterm prognostic factors of coronary artery disease in Korean adults are lacking, our experience with 404 hospitalized patients of acute myocardial infarction showed a relatively high prevalence of correctible risk factors. Smoking was the most highly associated (64.7%), followed by hypertension (36.7%), hypercholesterolemia (16.6%) and diabetes (15.0%)⁴⁾.

Serial previous observations^5–8) at our hospital upon the levels of serum lipid in Korean adults were reviewed retrospectively. The level of serum cholesterol has increased gradually over the past 30 years in Korean adults and such a trend was similar both in the male and female population (Fig. 1). According to the nationwide joint research carried out by the Korean Society of Circulation in 1990⁹⁾, serum cholesterol level in normal Korean adults (185±47.5mg/dl, mean±SD) was somewhat higher than expected and was pretty close to that of Caucasians (Table 1). Fortunately, however, there has been a growing public interest in the serum choleterol levels and its association with atherosclerotic cardiovascular diseases.

During the relatively short period of time between August 1991 and August 1992, our Department found 52 cases of familial hypercholesterolemia among 25 families, which had been considered extremely rare in Korea¹⁰⁾. Clinical features of patients with familial hypercholesterolemia were similar to those of western countries and it is very important to find such patients and family members as early as possible, since early treatment is needed to prevent those patients from premature coronary artery diseases and related cardiovascular complications.

We have also examined several other plasma lipid levels in healthy controls and coronary artery disease patients, such as high density lipoprotein cholesterol (HDL-cholesterol), apolipoprotein A1, B, E and lipoprotein (a), which have been considered to be closely related to coronary artery disease¹¹⁾. Of particular interest was that lipoprotein (a), thought to have a role in developing cornonary artery disease due to its structural similarity to that of plasminogen, appeared to be an independent risk foactor even in coronary artery disease patients whose plasma cholesterol levels were below 300 mg/dl (Fig. 2)¹²⁾.

Other major risk factors, like smoking and hypertension, are still much higher in Korea than those in developed countries and their influence cannot be measured with small scale studies. However, every effort should be made to reduce and eliminate modifiable risk factors through public education, since the risk for coronary artery disease increases sharply when these factors are accompanied by other risk factors such as hypercholesterolemia or diabetes.

The treatment of coronary artery disease is very diverse and cannot be generalized. Here, I would like to focus on recent advances and applications in the treatment of coronary artery disease such as thrombolytic therapy after acute myocardial infarction, interventional procedures like percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery.

Because of the limitations, such as shortage of equipment and funds, basic research on coronary artery disease is still in an early stage in Korea, though a few clinical investigations have been performed with some results. Despite many difficulties, our Department has already had considerable interest in the basic experimental studies, such as studies regarding serum lipid that is a major risk factor of coronary artery disease, especially lipoperoxides, apolipoproteins and lipoprotein (a). Recently, the assay of the LDL receptor was also conducted in patients with familial hypercholesterolemia. We also have been performing in vivo studies about vascular endothelial function associated with coronary artery artery spasm that is frequent in our country³⁵⁾ and animal experiments about reperfusion injury after coronary artery occlusion. Additionally, a few papers have been published regarding not only hemodynamic³⁶⁾, electrophysiologic³⁷⁾ changes and left ventricular function³⁸⁾ associated with coronary reperfusion after occlusion but also the modification of the reperfusion injury by removal of oxygen-free radicals using catalase and/or superoxide dismutase^39,40) and myocardial protection through ischemic preconditioning^41,42). Studies about effects of the residual critical coronary artery stenosis after coronary reperfusion and retroperfusion into the coronary sinus during coronary artery occlusion upon the infarct size are also underway. Experimental studies, using small animals like rodents, have been focused on the left ventricular remodeling after acute myocardial infarction and its modification with exercise training and/or pharmacological agents. Despite some efforts and trial from our Department and other laboatories, most research activities are still far from adequate to accomplish international reputation. However, growing widespread interest in basic experimental research among young Korean investigators are very encouraging and promising results would be expected in the near future through financial investment and persistent efforts.

Within the scope of our limited experiences first, the incidence of coronary artery disease is rapidly increasing; second, the frequency of correctible risk factors like smoking or hypertension are relatively high; third, several aspects or features of coronary artery diseases, distinct from those in western countries exist in Korea such as coronary artery spasm and coronary arterial involvement in Takayasu’s arteritis.

Therefore, through extensive and systematic studies of epidemiological and clinical studies, basic data regarding the present status of coronary artery disease in Korea, such as the prevalence, clinical features or characteristics and natural history of coronary artery disease, should be gathered and reestablished. Simultaneously, public education for the primary and secondary prevention of coronary artery disease to modify the risk factors should also be made as a nationwide movement. As a part of these efforts, the Korean Society of Circulation not only had perfomed a nationwide cooperative study to establish the serum lipid levels in normal Korean adults but, in this year, is supporting another cooperative project for the registry and natural history of acute myocardial infarction. However, these efforts are by no means sufficient and cannot guarantee success without strong support from the government.

Taken together, we should have a special interest and fervour not only in the diagnosis and management of patients but also in the clinical and experimental researches to resolve the problems peculiar to coronary artery diseases of our country.