Table 1.
Characteristics of the studies included in the analysis.
| Ref/study | Study design | Country of origin | Number of study participant | Age, mean (SD) (controls in case–control studies) | Proportion male, % (controls in case-control studies) | Recruitment | Follow-up (years) | CHD outcomes | Outcome ascertainment | APOE SNPs in HWE? | Original report stated presence of effect modification?a |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Published studies identified in the systematic review | |||||||||||
| Gustavsson et al. [9]/INTERGENE and SHEEP | Case–control | Sweden | 6389 | 54 (12) | 46.2 | Cases were patients with first or recurrent CHD and controls were randomly selected from the population | N/A | Acute MI, unstable angina, CHD exacerbations | MI: changes in blood levels of the enzymes CK and LDH, specified ECG-changes and autopsy findings according to the Swedish Association of Cardiologists in 1991 | Yes | Yes |
| Keavney et al. [7]/ISIS | Case–control | UK | 7385 | 46 (10) | 67.9 | Cases were patients with suspected AMI and controls selected from the relatives and spouses of the case group | N/A | Acute MI | Cardiac enzyme or electrocardiographic criteria, or both | Yes | No |
| Liu et al. [23]/Physicians' Health Study | Nested case–control | USA | 731 | 60 (9) | 100 | Male physicians registered with the American Medical Association | 12 | Fatal and nonfatal MI | WHO criteria for MI. Autopsies and deaths recorded for fatal MI diagnoses. | Yes | No |
| Talmud et al. [24]/Whitehall II | Prospective cohort | UK | 5380 | 57 (6) | 100 | Randomly selected among British civil servants | 5.8 | Fatal/nonfatal MI, angina (definitive or probable) | Fatal MI: national registries; nonfatal MI: MONICA criteria; angina: abnormal investigation such as angiography, exercise electrocardiography, stress imaging, study electrocardiogram or clinical confirmation | Yes | No |
| Published studies identified in the systematic review updated for incident CHD events | |||||||||||
| Humphries et al. [6]/NPHSII | Prospective cohort | UK | 2630 | 55.7 (3.2) | 100 | General practices, hospital clinics, coroner's offices | >10 | Fatal CHD (coronary deaths/fatal MI), nonfatal MI, coronary artery surgery and silent MI | WHO criteria | Yes | Yes |
| Studies not previously published | |||||||||||
| Copenhagen City Heart Study (CCHS) | Prospective cohort | Denmark | 8926 | 55.1(15.1) | 44 | Population-based | 34 | Fatal and nonfatal MI | ICD-8: 410; ICD-10: I21 and I22 | Yes | N/A |
| Copenhagen General Population Study (CGPS) | Prospective cohort | Denmark | 57,942 | 57.1(13.3) | 44 | Population-based | 34 | Fatal and nonfatal MI | ICD-8: 410; ICD-10: I21 and I22 | Yes | N/A |
| Czech post-MONICA | Prospective cohort | Czech Republic | 1875 | 55.0 (10.3) | 45 | Population-based | 6 | Nonfatal MI | ICD-10: I21 and I22 | Yes | N/A |
| ELSA | Cohort | UK | 5020 | 67.5 (9.8) | 46 | Respondents of Nationwide survey | 11 | Fatal and nonfatal CHD | Fatal CHD (ICD-10: I20–I25) and self-reported CHD | Yes | N/A |
| EPIC-Netherlands | Nested case–control | Netherlands | 2129 | 54.1 (10.1) | 22 | Population-based | 13 | Fatal and nonfatal MI | ICD-9: 410; ICD-10: I21, I22 | Yes | N/A |
| EPIC-Norfolk | Prospective cohort | UK | 22,838 | 59.2 (9.2) | 46 | Population-based | 10 | Fatal and nonfatal MI | ICD-10: I21 and I22 | Yes | N/A |
| HAPIEE-Czech | Prospective cohort | Czech Republic | 6256 | 58.3 (7.1) | 46 | Population-based | 7 | Fatal and nonfatal MI | ICD-10: I21 and I22 | Yes | N/A |
| MRC GP Research Framework Investigators, TPT trial [30] | Randomized clinical trial | UK | 2503 | 56.1 (6.7) | 100 | Hospital clinics | 9 | Coronary death, fatal and nonfatal MI | WHO criteria | Yes | N/A |
CHD, coronary heart disease; CK, creatine kinase; ECG, electrocardiogram; HWE, Hardy Weinberg Equilibrium; ICD, international classification of disease; LDH, lactate dehydrogenase; MI, myocardial infarction; N/A, not applicable; WHO, World Health Organization.
a
Effect modification by smoking status in the APOE–CHD relationship.