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.