Circ J 2006; 70: 1256–1262 Current Status of the Background of Patients With Coronary Artery Disease in Japan The Japanese Coronary Artery Disease Study (The JCAD Study) The Japanese Coronary Artery Disease (JCAD) Study Investigators* Background Although the morbidity and mortality of coronary artery disease (CAD) vary widely with race and lifestyle, Japanese CAD patients have been clinically managed according to the guidelines of Western coun- tries. To draft guidelines specifically for Japanese CAD patients, a database that describes how Japanese CAD patients are currently managed and the outcomes of those managements practices is required. Methods and Results Patients diagnosed as having 75% or higher stenosis according to the American Heart Association classification in at least 1 branch of the coronary arteries by cardiac catheterization were enrolled in the study. Of 15,628 patients screened from April 2000 to March 2001, 13,812 of them met the inclusion criteria and were followed up for a mean period of 2.7 years. The incident rate of events was 62.8 per 1,000 patients-year including all-cause mortality of 17.5 and total cardiac events of 47.4 per 1,000 patients-year which is much higher than previous reports in Japan. The incident rate of acute myocardial infarction in this study cohort was 7.5 events per 1,000 patients-year. Conclusion The database provides a large body of information on Japanese CAD patients who have significant coronary atherosclerosis diagnosed by coronary angiography, which will be useful for planning future random- ized controlled trials. (Circ J 2006; 70: 1256–1262) Key Words: Coronary angiography; Coronary artery disease; Cohort study; Internet registration he Japanese population dynamic statistics show that style, pharmacokinetics etc of Japanese are different from there were 159,545 deaths from heart disease in Westerners lead to us conducting this study to draft guide- T 2003, consisting 15.7% of all-cause deaths.1 Sever- lines applicable for Japanese. al decades ago Japanese used to be more susceptible to We designed the present study to investigate the risk stroke than cardiac diseases, but there is a now remarkably factors and current status of the medical management of declining trend in the mortality rate of stroke in the Japanese CAD patients and how they are reflected in the Japanese population.2 On the other hand, the incidence of cerebro- and cardiovascular events. To meet this purpose, and mortality from coronary heart disease have increased we selected hospitals across Japan where more than 100 slightly in the past couple of decades3 and the incidence of cases of coronary angiography (CAG) are performed annu- such important risk factors as obesity4 and hyperlipidemia5 ally. As a result, 217 hospitals participated in the study and is increasing. a total of 15,628 patients were registered initially. Thus, the Epidemiological studies have shown that the incidence purpose of the present study (Japanese Coronary Artery and mortality of coronary artery disease (CAD) are higher in Disease Study (JCAD Study)) was to explore the current Western countries than in Asian countries.6 The Framingham status of Japanese CAD patients and clarify the difference Study showed that the risk factors of CAD consist of in CAD outcomes between men and women or among hyperlipidemia, hypertension, smoking and diabetes melli- those who have different numbers of risk factors, so that tus (DM),7 which were incorporated into several clinical new guidelines for Japanese CAD patients can be drafted. guidelines worldwide. Although several epidemiological We are presenting the outline of the JCAD Study database studies on CAD risks have been conducted in Japan, the re- in this paper. Detailed data related to CAD risk factors, sults have not been sufficient to define treatment strategies medical management, and occurrence of cerebro- and car- for Japanese patients, leaving Japanese cardiologists to use diovascular events with various drug treatments will be the Western guidelines for practical reasons. Furthermore, published subsequently. the fact that the mortality of Japanese CAD patients is 20– 30% of Westerners and that the genetic background, life- Methods Patients (Received February 3, 2006; revised manuscript received July 27, The complete protocol of this study with the purpose, 2006; accepted August 3, 2006) *The JCAD Study Investigators are listed in Appendix1. study design, criteria for eligibility and exclusion of pa- Mailing address: Ryozo Nagai, MD, Department of Cardiovascular tients, clinical measures, events and statistical analyses has Medicine, Graduate School of Medicine, University of Tokyo, 7-3-1 been published elsewhere.8 Briefly, consecutive patients Hongo, Bunkyo-ku, Tokyo 113-8655, Japan undergoing CAG for various reasons and who were diag- Circulation Journal Vol.70, October 2006 JCAD Study 1257 Table 1 Baseline Characteristics of the Population in the JCAD Cohort Study Total Male Female Number 13,812 10,626 3,186 Age (years) 65.5±9.8 64.5±9.8 68.7±9.1 Diagnosis at the time of registration AMI (%) 2,955 (21.4) 2,318 (21.8) 637 (20.0) OMI (%) 3,913 (28.3) 3,210 (30.2) 703 (22.1) uAP (%) 2,049 (14.8) 1,501 (14.1) 548 (17.2) sAP (%) 3,926 (28.4) 2,852 (26.8) 1,074 (33.7) Other (%) 969 (7.0) 745 (7.0) 224 (7.0) Risk factors Hyperlipidemia (%) 7,547 (54.6) 5,551 (52.2) 1,996 (62.6) Impaired glucose tolerance (%) 5,570 (40.3) 4,193 (39.5) 1,377 (43.2) Hypertension (%) 7,951 (57.6) 5,899 (55.5) 2,052 (64.4) Obesity (%) 4,538 (32.9) 3,499 (32.9) 1,039 (32.6) Smoking habit (%) 5,437 (39.4) 5,010 (47.1) 427 (13.4) Familial history of CAD (%) 2,281 (16.5) 1,756 (16.5) 525 (16.5) AMI, acute myocardial infarction; OMI, old myocardial infarction; uAP, unstable angina pectoris; sAP, stable angina pectoris; CAD, coronary srtery disease. Table 2 Incident Rate of Events Total incident rate Male incident rate Female incident rate Events p value /1,000 patients-year All events including death 62.8 61.5 67.1 0.1083 Death All-cause death 17.5 17.6 16.9 0.6037 Cardiac death 7.6 7.5 8.1 0.6243 Cerebral death 0.9 0.9 0.7 0.4807 Vascular death 0.5 0.6 0.0 0.0241 Other causes 8.5 8.6 8.1 0.6475 Cardiac events 47.4 45.6 53.3 0.0098 Acute myocardial infarction 7.5 7.6 7.1 0.5692 Unstable angina pectoris 22.8 21.5 27.2 0.0035 Resuscitated cardiac arrest 0.4 0.4 0.4 0.7825 Congestive heart failure 10.5 9.9 12.5 0.0427 Bypass graft surgery 4.7 4.8 4.4 0.5833 CPAOA 2.8 2.8 2.7 0.8556 Cerebral events Cerebral infarction or hemorrhage 5.7 5.9 5.2 0.4432 Transient ischemic attack 1.0 1.0 0.9 0.7964 Vascular events Aortic aneurysm rupture 0.5 0.7 0.0 0.0136 Aortic dissection 0.3 0.5 0.0 0.0491 CPAOA, cardiopulmonary arrest on arrival. nosed as having 75% or higher stenosis according to the set up and clinical information of the patients was sent to American Heart Association classification in at least 1 the central computer through a Web-based interface. Data branch of the coronary arteries were primary candidates. were sent to the server at the time of patient registration The reasons for performing CAG included old and acute (baseline characteristics) and every 6 months thereafter for myocardial infarction (MI), stable and unstable angina, 3 years, and when events occurred. chronic heart failure, and clinical demand to perform the procedure. All CAG was performed after written informed Investigations consent was given, except in emergency cases where writ- The data collected included CAD risk factors such as ten consent was not available. The patients were informed, hyperlipidemia, impaired glucose tolerance (IGT) includ- however, even in such cases of the risks and benefits of the ing diabetes mellitus, hypertension, smoking, and drinking, procedure. When follow-up data of more than 6 months and markers such as serum total cholesterol, triglyceride, could be obtained or when a cerebro- and cardiovascular systolic and diastolic blood pressures and left ventricular event occurred, including death, within 6 months of enroll- ejection fraction. Complete information about the data ment, the subjects were included in the final analysis. The collection was reported previously.8 patients were followed up for 3 years. Clinical events to be registered in the database were defined as follows: all-cause deaths including cardiac, cere- Data Registration and Accumulation bral, vascular and other deaths, and cerebral, cardiac and All follow-up data were registered electronically over vascular events. Cerebral events included cerebral hemor- the Web. Detailed methods of data registration have been rhage, cerebral infarction and transient ischemic attack. described previously.8 Briefly, a central database server was Cardiac events consisted of fatal and non-fatal MI, unstable Circulation Journal Vol.70, October 2006 1258 THE JCAD STUDY INVESTIGATORS Table 3 Difference in the Incident Rate of Events Between MI and Non-MI Patients Non-MI incident rate MI incident rate Events p value /1,000 patients-year All events including death 62.8 62.8 0.7292 Death All-cause death 14.6 20.4 0.0000 Cardiac death 5.2 10.1 0.0000 Cerebral death 0.9 0.9 0.7185 Vascular death 0.5 0.4 0.5379 Other causes 8.0 9.0 0.2353 Cardiac events 47.1 47.6 0.6443 Acute myocardial infarction 5.7 9.4 0.0000 Unstable angina pectoris 27.5 18.0 0.0000 Resuscitated cardiac arrest 0.3 0.5 0.1865 Congestive heart failure 6.4 14.7 0.0000 Bypass graft surgery 5.9 3.5 0.0008 CPAOA 2.2 3.3 0.0423 Cerebral events Cerebral infarction or hemorrhage 6.4 5.1 0.1265 Transient ischemic attack 1.1 1.0 0.8492 Vascular events Aortic aneurysm rupture 0.7 0.4 0.2217 Aortic dissection 0.5 0.2 0.1747 MI, myocardial infarction.