Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 10 1 2015 10 13 34 42 EN Seyed Hesameddin Abbasi Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Seyed Ebrahim Kassaian Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Saeed Sadeghian Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Abbasali Karimi Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Soheil Saadat Sina Trauma Research Center, Tehran University of Medical Sciences, Tehran. Iran. Flora Peyvandi Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico Milano, Angelo Bianchi Bonomi Hemophilia and Thrombosis Centre, Milan, Italy AND Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy. Arash Jalali Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Tahereh Davarpasand Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Nazila Shahmansouri Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Masoumeh Lotfi-Tokaldany Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Maryam Amiri-Abchouyeh Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Farah Ayatollahzade-Isfahani Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran. Frits Rosendaal Department of Clinical Epidemiology and Department of Thrombosis and Haemostasis, Leiden University Medical Center, Leiden, The Netherlands. 2015 10 13 2015 10 13 Background: Data on premature coronary artery disease (CAD) are scarce. The Tehran Heart Center's Premature Coronary Atherosclerosis Cohort Study (THC-PAC) is the first study of its kind in the Middle East to assess major adverse cardiac events (MACE) in young CAD patients. Methods: The cohort consists of CAD patients, males ≤ 45 years old and females ≤ 55 years old. The participants are residents of Tehran or its suburbs and underwent coronary angiography between June 2004 and July 2011. A 10-year follow-up, via either clinical visits or telephone calls at least once a year, was commenced in August 2012. The end point is considered MACE, encompassing death, myocardial infarction, stroke, new coronary involvement, percutaneous coronary intervention, and coronary artery bypass grafting. Results: The cohort comprises 1232 eligible patients (613 [49.8%] males) at a mean age of 45.1 years (SD = 5.8). High frequencies of conventional risk factors, including hyperlipidemia (884 [71.8%]), hypertension (575 [46.7%]), positive family history (539 [43.8%]), cigarette smoking (479 [38.8%]), and diabetes mellitus (390 [31.7%]), were seen in the participants. The mean body mass index (BMI) of the enrolled patients was high (29.2 ± 4.8 kg/m2), and 532 (43.3%) and 440 (35.8%) of them were overweight and obese, respectively. The females’ BMI was higher (30.4 ± 5.3 vs. 28.0 ± 3.9 kg/m2; P < 0.001) and they had a greater mean abdominal circumference (99.9 ± 13.5 vs. 98.1 ± 9.3 cm; P = 0.035). Between August 2012 and August 2013, follow-up was successful in 1173 (95.2%) patients (median follow-up duration = 55.3 months, 95%CI: 53.5-57.0 months). Conclusion: Our younger patients with CAD had a high frequency of risk factors compared to the same-age general population and all-age CAD patients, which may predispose them to higher incidence of recurrent MACE. https://rhythm.tums.ac.ir/index.php/jthc/article/view/362 https://rhythm.tums.ac.ir/index.php/jthc/article/download/362/355