Objective: To investigate cholesteryl ester transfer protein (CETP) gene polymorphism -629C/A among Han Chinese patients with coronary heart disease (CHD) in Tianjin region, and to assess the influence of genetic factors on therapeutic effect of atorvastatin and clinical outcome in order to provide a pharmacogenomic basis for personalized treatment.
Methods: From October 2010 to July 2011, 232 patients with angiographically confirmed CHD were recruited. Polymorphism of position -629 of CETP gene promoter was determined with polymerase chain reaction - restricted fragment length polymorphism (PCR-RFLP) method. Serum level of CETP was determined with enzyme-linked immunosorbent assay (ELISA). Lipid level in all patients was determined at baseline and after 12 months of treatment with 20 mg/d atorvastatin. Clinical follow-up was carried out for more than a year (12-23 months). Major adverse cardiac events including death, non-fatal infarction, revascularization and stroke (MACE) were recorded. A Kaplan-Meier log-rank test was used to compare MACE-free survival for individuals with various genotypes.
Results: The frequency of -629A allele was 0.408. Compared with CC or CA genotypes, individuals with AA genotype had lower CETP levels and higher high-density lipoprotein cholesterol (HDL-C) levels, albeit without statistical significance (F = 0.893, P = 0.411 and F = 1.279, P = 0.282, respectively). There also appeared to be a negative correlation between serum HDL-C and CETP levels, though no statistical significance was detected (r = -0.151, P = 0.081). After 12 months atorvastatin therapy, individuals with CC genotype had greater reduction of low-density lipoprotein cholesterol (LDL-C), reduced LP(a) and elevated HDL-C compared with CA or AA genotypes. LDL-C level has decreased by 35.41% in CC homozygotes, 18.84% in CA heterozygotes and 8.15% in AA homozygotes (P = 0.001). HDL-C level has increased by 14.37% in CC homozygotes, 10.48% in CA heterozygotes and 6.64% in AA homozygotes, respectively. However, above changes did not reach statistical significance (P = 0.470). The incidence of MACE after a mean follow-up of (18.66 ± 5.99) months was 7.76%, which included 2 (0.86%) deaths, 5 (2.16%) non-fatal infarctions, 9 (3.88%) revascularizations and 2 (0.86%) strokes. The cumulative MACE-free survival rates were 92.4%, 85.3% and 65.0% for CC, CA and AA genotypes, respectively (Log-rank P = 0.444).
Conclusion: Our results suggested that AA variant for the -629A allele of CETP gene had higher HDL-C levels and reduced CETP levels, though patients with CC genotype appeared to have better benefited from statin therapy with reduction in LDL-C and LP(a) levels. Long-term clinical prognosis was however not affected by the 3 genotypes.