Table 2. The impact of age on CAD .

CAD: Coronary artery disease, CVD: Cardiovascular disease, CCTA: Coronary computed tomography angiography, MACE: Major adverse cardiovascular events, LM: Left main, MI: Myocardial infarction, PCAD: Premature coronary artery disease, HDL: High-density lipoprotein, Lp(a): Lipoprotein (a), CAC: Coronary artery calcium, AMI: Acute myocardial infarction, LTL: Leukocyte telomere length, LCPUFAs: Long-chain polyunsaturated fatty acids

Identification and Year of Publication	Outcome Measures	Key Findings	Limitations
Nakazato et al. (2014) [42]	The observational study examined the relation between the degree and severity of coronary artery disease (CAD) through CCTA and the risk and frequency of major adverse cardiac occurrences with respect to age.	Patients aged above 65 have greater MACE risks for on-obstructive CAD with one or two vessels affected, in contrast to normal patients below 65 years of age. Patients below 65 years of age with three vessels and LM disease have a greater risk for MI and late revascularization. The degree and severity of MACE were more elevated in patients over 80 years old.	Selection, referral, and misclassification biases are possible.
Patil et al. (2020) [43]	The observational study evaluated the risk determinants and clinical and angiographic picture of young individuals from India living in rural areas showing premature coronary artery disease (PCAD).	Traditional risk factors, including decreased HDL volume, smoking, and abdominal obesity, have a significant impact on the development of early coronary artery disease in young people in rural areas.	Dietary patterns of rural youth were not known and may have thus impacted the development of CAD.
Stătescu et al. (2023) [44]	This systematic review evaluated the classic risk determinants of myocardial infarction in the “young”, emphasizing the clinical ramifications of lipoprotein (a).	The occurrence of acute myocardial infarction is rising in younger individuals. Raised volumes of Lp(a) are a critical determinant of the risk of cardiovascular disease associated with atherosclerotic plaque, particularly in patients and other individuals with familial hypercholesterolemia. Treatments that decrease the volumes of Lp(a) may improve the outcomes of younger patients diagnosed with AMI.	The study fails to determine the exact impact of Lipoprotein A (Lp(a)) lowering agents on the medical management of CAD and relies on the ongoing Phase 3 trial of a Lp(a) lowering agent in a randomized, double-blinded placebo-controlled trial.
Javaid et al. (2022) [45]	The study determined the probability of coronary artery calcium (CAC) >0 and developed age-sex-race percentiles for U.S. adults aged 30–45 years.	The incidence of CAC in white men was >0 of 26%, Black males of 16%, White females of 10%, and Black females of 7%. Women were put at the >90th percentile with a CAC >0. 34-year-old White men were in the 90th percentile in contrast to 37-year-old Black men, according to CAC >0.	The study did not have data on East Asians, Hispanics, South Asians, or other races and ethnicities. Any long-term clinical outcomes were also not studied.
Nordström et al. (2020) [46]	The cohort study assessed the risk of CVD in a main prevention scheme for a community of people in their 70s.	In a community of people in their 70s, a main multifaceted prevention scheme was linked to a lower risk of stroke and ischemic heart disease. Among participants who were at higher risk, the preventative program was linked to improved hypertension and hypercholesterolemia treatment.	Randomization was not done due to ethical reasons. The study could only guess if any effects on CVD are attributable to alterations in blood pressure and cholesterol volumes as a result of improved medication and/or behavioral changes as a result of the motivational interview, and no proof of causal effects could be established.
Wilson et al. (2014) [47]	The observational study measured the differences in unnoticed diagnosis and billing of care for aged individuals with acute myocardial infarction (AMI) who show up in the emergency unit. Also, this study aimed to recognize the emergency unit and hospital features connected to the differences.	The number of unnoticed acute myocardial infarction (AMI) diagnoses and the billing of care for individuals equal to or above the age of 65 showing up at the emergency unit varied in different hospitals. These individuals were released earlier after their visit and admission to the hospital.	The study relied on administrative data only and utilized a short index of coding for medical release diagnosis of conditions indicative of cardiac ischemic diseases, thus underestimating the true incidences of unnoticed AMI cases. The billing of care was studied only from the payer's point of view and not from the hospital’s or the patient's point of view.
Kalstad et al. (2019) [48]	The randomized controlled trial explored the interconnections among serum polyunsaturated fatty acids, leukocyte telomere length, serum, cardiovascular risk determinants, diet, and characteristics of myocardial infarction (MI) in senior patients.	In this analysis, there was a small connection between linoleic acid but no considerable relation between LTL (leukocyte telomere length) and marine LCPUFAs (long-chain polyunsaturated fatty acids) has been identified. Extended telomeres seem to be associated with balanced nutrition.	The study doesn't have a control group of individuals within a similar age range without CVD risks. Medication taken previously for the index infarction may have affected the outcomes.