introducing the tehran heart center's premature coronary atherosclerosis cohort: thc-pac study

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/m 2 ), 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.