Abstract
BACKGROUND: We sought to determine whether there are differences in enrolled patients' risk factors in published percutaneous coronary intervention (PCI) trials between various continents. METHODS: We systematically identified clinical trials evaluating PCI interventions through PubMed. We reviewed 701 studies between 1990 and 2014 from North America (N=135), Europe (N=403), and Asia (N=163), examining the prevalence of cardiovascular risk factors-hypertension (HTN), diabetes mellitus (DM), hyperlipidemia (HL), smoking, sex, and body mass index. We performed meta-regression with random- and mixed-effects models to compare patient baseline characteristics between continents and linear meta-regression analysis to test trends over time. RESULTS: In meta-regression with random-effects model, North American trials recruited the lowest proportion of male participants (71.32%), followed by Asian (74.41%) and European trials (76.47%; P<.0001). North American trials enrolled the highest proportion of patients with HTN (63.17%, P=.0035) and HL (63.72%, P<.0001), whereas Asia enrolled the highest proportion of DM patients (29.64%, P<.0001) and smoking (38.41%, P=.0144). When adjusting for other moderators such as publication date, body mass index, and sex in meta-regression with mixed-effects model, age was significantly positively correlated with HTN, HL, DM, and smoking (P<.001). Body mass index was significantly higher in Europe and North America than in Asia. All enrollment risk factors demonstrated (β<0.02) statistically significant temporal trends over time, except for sex. CONCLUSIONS: There are major continental differences in risk factors among patients enrolled in PCI trials from various continents. Clinical trial results may not be applicable to patient populations from another region.