Non-traditional risk factors for myocardial infarction in adults under forty: A systematic review of emerging trends

Table 1 Study characteristics and participant demographics

Ref.	Country	Study design	Sample size	Age range	Sex distribution	Comorbidities	MI classification
Krittanawong et al[18], 2020	United States	Retrospective cohort (NIS)	5764755 (< 55 years), 1149185 AMI	< 55 (mean 45.1 AMI)	66.6% men, 33.4% women (AMI)	Obesity, smoking, HTN, diabetes, HIV, SLE, OSA, RA	STEMI, NSTEMI
Zhu et al[19], 2024	United States	Prospective cohort (VIRGO)	2979	18-55 (median 48)	67.2% women, 32.8% men	HTN, diabetes, obesity, smoking, alcohol abuse, prior CVD, COPD	STEMI, NSTEMI, EF < 40%
Dreyer et al[20], 2021	United States	Prospective cohort (VIRGO)	2979	18-55 (mean 47.1)	67.4% women, 32.6% men	HTN, diabetes, obesity, smoking, prior AMI, COPD	STEMI, NSTEMI
Gupta et al[21], 2020	India	Case-control	154 (77 MI, 77 controls)	18-45 (mean 35.3 MI)	65 men/12 women (MI), 58 men/19 women (controls)	Excluded smokers, diabetics, BMI > 35	AWMI, IWMI, LWMI
Cho et al[22], 2019	South Korea	Population-based cohort	2705090	20 + (stratified)	Not split, large population	HTN, diabetes, hypercholesterolemia, SES, depression	AMI (ICD-10)
Fan et al[23], 2019	China	Prospective cohort	804	18-85 (mean 57.5)	82.6% men	HTN, diabetes, hyperlipidemia, prior MI/PCI, smoking	ACS (STEMI/NSTEMI/UA)
Smolderen et al[24], 2015	United States, Spain, Australia	Cohort (VIRGO)	3572	18-55 (median 48)	67.1% women, 32.9% men	HTN, diabetes, obesity, smoking, hypercholesterolemia, prior AMI, CHF	STEMI, NSTEMI
Turati et al[25], 2015	Italy	Case-control	760 cases, 682 controls	19-79 (median 61 MI)	76.3% men (MI)	HTN, diabetes, hyperlipidemia, BMI	Non-fatal AMI
Orth-Gomér et al[26], 1986	Sweden	Case-control	210 (89 MI, 121 controls)	18-45 (mean 39.5)	89 men (MI), 121 men (controls)	HTN, diabetes, hyperlipidemia, smoking	MI (survivors < 45)
Zhao et al[27], 2023	China	Cross-sectional	8103	18-99 (mean 50.3)	53.5% women, 46.5% men	HTN, diabetes, obesity	Not MI-specific
Head et al[28], 2019	United States	Cross-sectional autopsy (PDAY)	2651	15-34 (mean 24.8)	75% men, 25% women	Excluded major comorbidities	Subclinical atherosclerosis
Lu et al[29], 2022	United States	Case-control (VIRGO/NHANES)	2264 AMI, 2264 controls	18-55 (median 48)	68.9% women, 31.1% men	HTN, diabetes, hypercholesterolemia, obesity, depression, low income, family history	STEMI, NSTEMI, type 1
Jariwala et al[30], 2022	India	Retrospective, multicenter	3656 (< 45 years PCI)	< 45 (mean men 37.4, women 41.1)	69.2% men, 30.8% women	HTN, diabetes, overweight, dyslipidemia, family history, smoking, alcoholism	ACS (STEMI/NSTEMI/UA)

NIS: National inpatient sample; VIRGO: Variation in recovery: Role of gender on outcomes of young AMI patients (a major multinational study); PDAY: Pathobiological determinants of atherosclerosis in youth (study); NHANES: National Health and Nutrition Examination Survey; MI: Myocardial infarction; HTN: Hypertension; HIV: Human immunodeficiency virus; SLE: Systemic lupus erythematosus; OSA: Obstructive sleep apnea; RA: Rheumatoid arthritis; STEMI: ST-elevation myocardial infarction; NSTEMI: Non-ST-elevation myocardial infarction; CVD: Cardiovascular disease; COPD: Chronic obstructive pulmonary disease; EF: Ejection fraction; AMI: Acute myocardial infarction; BMI: Body mass index; AWMI: Anterior wall myocardial infarction; IWMI: Inferior wall myocardial infarction; LWMI: Lateral wall myocardial infarction; PCI: Percutaneous coronary intervention; ACS: Acute coronary syndrome; UA: Unstable angina.