Risk Factor Patterns for Premature Versus Late-Onset Coronary Artery Disease in Iran: A Systematic Review and Meta-Analysis

Coronary risk factor profiles according to different age categories in premature coronary artery disease patients who have undergone percutaneous coronary intervention

Many studies have investigated the coronary risk factors (CRFs) among premature coronary artery disease (PCAD) patients. However, reports on the proportion and CRFs of PCAD according to different age cut-offs for PCAD is globally under-reported. This study aimed to determine the proportion of PCAD patients and analyse the significant CRFs according to different age cut-offs among percutaneous coronary intervention (PCI)-treated patients. Patients who underwent PCI between 2007 and 2018 in two cardiology centres were included (n = 29,241) and were grouped into four age cut-off groups that defines PCAD: (A) Males/females: < 45, (B) Males: < 50; Females: < 55, (C) Males: < 55; Females: < 60 and (D) Males: < 55; Females: < 65 years old. The average proportion of PCAD was 28%; 9.2% for group (A), 21.5% for group (B), 38.6% and 41.9% for group (C) and (D), respectively. The top three CRFs of PCAD were LDL-c level, TC level and hypertension (HTN). Malay ethnicity, smoking, obesity, family history of PCAD, TC level and history of MI were the independent predictors of PCAD across all age groups. The proportion of PCAD in Malaysia is higher compared to other studies. The most significant risk factors of PCAD are LDL-c, TC levels and HTN. Early prevention, detection and management of the modifiable risk factors are highly warranted to prevent PCAD.

Contribution of genetic variants in the development of familial premature coronary artery disease in a cohort of cardiac patients

Coronary artery disease (CAD), the most prevalent cardiovascular disease, is the leading cause of death worldwide. Heritable factors play a significant role in the pathogenesis of CAD. It has been proposed that approximately one-third of patients with CAD have a positive family history, and individuals with such history are at ~1.5-fold increased risk of CAD in their lifespans. Accordingly, the long-recognized familial clustering of CAD is a strong risk factor for this disease. Our study aimed to identify candidate genetic variants contributing to CAD by studying a cohort of 60 large Iranian families with at least two members in different generations afflicted with premature CAD (PCAD), defined as established disease at ≤45 years in men and ≤55 years in women. Exome sequencing was performed for a subset of the affected individuals, followed by prioritization and Sanger sequencing of candidate variants in all available family members. Subsequently, apparently healthy carriers of potential risk variants underwent coronary computed tomography angiography (CCTA), followed by co-segregation analysis of the combined data. Putative causal variants were identified in seven genes, ABCG8, CD36, CYP27A1, PIK3C2G, RASSF9, RYR2, and ZFYVE21, co-segregating with familial PCAD in seven unrelated families. Among these, PIK3C2G, RASSF9, and ZFYVE21 are novel candidate CAD susceptibility genes. Our findings indicate that rare variants in genes identified in this study are involved in CAD development.

Risk factors for premature coronary artery disease (PCAD) in adults: a systematic review protocol

PCAD possesses a public health challenge resulting in years of productive life lost and an escalating burden on health systems. Objective of this review is to compare modifiable and non-modifiable risk factors for PCAD compared to those without PCAD. This review will include all comparative observational studies conducted in adults aged >18 years with confirmed diagnosis of PCAD (on angiography) compared to those without PCAD. Databases to be searched include; PubMed, CINAHL, Embase, Web of Science, and grey literature (Google Scholar). All identified studies will be screened for title and abstract and full-text against the inclusion criteria on Covidence software. Data relevant to exposures and outcomes will be extracted from all included studies. All studies selected for data extraction will be critically appraised for methodological quality. Meta-analysis using random-effects model will be performed using Review Manager 5.3. Effect sizes for categorical risk factors will be expressed as odds ratios with 95% confidence intervals. For risk factors measured in continuous form, mean difference (if units are consistent) otherwise standardized mean difference (if units are different across studies) will be reported. Heterogeneity between studies will be assessed using I 2 test statistics. GRADE will be used to assess the certainty of the findings. Systematic review registration number:PROSPERO Registration # CRD42020173216.

Risk factors of premature coronary artery disease in Iran: A systematic review and meta-analysis

BACKGROUND

The aim of this study was to determine the mean age at which coronary artery disease (CAD) hase decreased in recent years in Iran. This systematic review and meta-analysis compares the prevalence of different risk factors of premature CAD (PCAD) in patients vs healthy individuals.

METHODS

Medline, Web of Science, Embase and Scientific Information Database were searched for studies about PCAD risk factors in Iran until 28 October 2017. Observational studies of Iranians, comparing risk factors between patients with PCAD and age- and sex-matched healthy subjects, were included. Fixed-effects and random-effects model were used for pooling data. Odds ratio (OR) with 95% CI and mean difference were used for effect size estimation among studies.

RESULTS

Twelve studies were eligible for meta-analysis. Diabetes mellitus (OR: 2.4, 95% CI: 1.9-3.03; P = 0.0001, I²  = 25.5%; P = 0.2), family history of CAD (OR: 2.09, 95% CI: 1.22-3.6; P = 0.007, I²  = 86%; P = 0.0001), dyslipidaemia (OR: 2.05, 95% CI: 1.15-3.64; P = 0.01, I²  = 54%; P = 0.08), smoking (OR: 1.65, 95% CI: 1.11-2.46; P = 0.01, I²  = 77.2%; P = 0.000) and hypertension (OR: 1.35, 95% CI: 1.21 to-1.50; P < 0.001, I²  = 31%, P = 0.1) associated with PCAD. Sensitivity analysis demonstrated that patients with PCAD had significantly lower levels of high-density lipoprotein (HDL) cholesterol and significantly higher levels of triglycerides compared to healthy subjects (MD: -2.56, 95% CI: -3.54 to -1.58, P < 0.001, I²  = 42%, P = 0.01 and MD: 21.17, 95% CI: 14.73-27.62, P < 0.001, I²  = 80.12%, P < 0.001, respectively). It should be noted that although high levels of heterogeneity in LDL and HDL values among the studies were observed, when dyslipidaemia was studied as a binary variable, no significant heterogeneity among studies was observed.

CONCLUSION

Diabetes mellitus, family history of CAD, dyslipidaemia, smoking, and hypertension were significantly and positively associated with CAD in young adults compared to healthy age- and sex-matched population in Iran.