论文摘要:
Background Both genetic and clinical factors could influent
the long-term prognosis after coronary artery bypass graft (CABG) surgery.
There exist clinical risk scores to predict the adverse events after CABG, the
efficacy and quality of these predicting models still needs to be improved.
Several genetic variants were associated with poor prognosis after CABG. This
study aims to put forward a gene-based risk score system to predict long-term
prognosis after CABG.
Methods A cohorts of 1547 patients undergoing
CABG surgery were examined, and the adverse events after the index CABG were
followed up. Patients were consecutively recruited from Fuwai Hospital, Chinese
Academy of Medical Sciences and Peking Union Medical College (Beijing, China)
between December 2007 and July 2010. The study protocol was approved by the
Review Board of Fuwai Hospital,Peking Union Medical College (Beijing, China). We
have complied with the World Medical Association Declaration of Helsinki
regarding ethical conduct of research involving human subjects and/or animals.
All patients were provided written informed consent to be involved in the
study. The median follow-up time of these patients was 6.06 years. The adverse
events (MACCE) includes all-cause death, new-onset nonfatal myocardial
infarction, new-onset nonfatal stroke and repeat revascularization. For every
patient, ninety-five single-nucleotide polymorphisms (SNPs) were tested. These
SNPs were reported associating with coronary artery diseases in GWA studies
and/or studies of candidate genes. For every SNP, a variable recording the allele
count (0, 1, 2) was used to perform statistical analysis. Cox proportional
hazard models were used to identify genomic predictors of MACCE. The level of
significance was set to P-value < 0.05. Significant SNPs were selected as
risk SNPs to further study. The sums of the allele count of all the remained risk
SNPs were calculated as a risk score. The risk score were validated in Cox
proportional hazard models. We also calculated Cox regression C statistics of the
genetic risk score to evaluated the efficacy of this predicting model.
Results In the 6-year follow up period, there were 329
out of 1547 patients (21.27%) suffered in adverse events. Seven SNPs were
selected as risk SNPs. They were IL6 rs1800796 (HR=1.268, 95% CI: 1.084-1.482,
P=0.003), ITGA2 rs1126643 (HR=1.270, 95% CI: 1.075-1.500, P=0.005), THBD
rs1042579 (HR=1.221, 95% CI: 1.027-1.450, P=0.023), THBD 3176123 (HR=1.207, 95%
CI: 1.018-1.431, P=0.030), P2RY12 rs2046934 (HR=1.230, 95% CI: 1.017-1.487,
P=0.033) and CYP2C19 rs4244285 (HR=1.179, 95% CI: 1.003-1.385, P=0.046).
GenoSCORE of all patients ranged from 0 to 10. When the GenoSCORE increased for
1 unit, the risk of MACCE would increase for 1.172 times (P=1.57*10-7).
Then, the patients were divided into four groups according to GenoSCORE, namely
the low risk group (GenoSCORE: 0 and 1), intermediate risk group (GenoSCORE: 2,
3 and 4), high risk group (GenoSCORE: 5, 6 and 7) and extremely high risk group
(GenoSCORE: 8,9 and 10). The HR of the intermediate risk group, high risk group
and extremely risk group were 1.361 (p=0.074), 2.109 (p=7.75*10-5)
and 4.212 (p=2.30*10-5) compared to the low risk group. The Cox
regression C statistics of GenoSCORE was 0.798, which means it can predict the
adverse events accurately.
Conclusions We established a genetic risk score based on the association between SNPs and
poor prognosis after CABG, and the GenoSCORE can predict the adverse events
after CABG accurately.