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Aortic calcification is an important independent predictor of future cardiovascular events. We performed a genome-wide association meta-analysis to determine SNPs associated with the extent of abdominal aortic calcification (n = 9,417) or descending thoracic aortic calcification (n = 8,422). Two genetic loci, HDAC9 and RAP1GAP, were associated with abdominal aortic calcification at a genome-wide level (P

It is unknown if lifelong exposure to increased hemodynamic stress from an elevated resting heart rate (HR) may contribute to aortic valve calcium (AVC). We performed multivariate regression analyses using data from 1,266 Framingham Heart Study (FHS) Offspring cohort participants and 6,764 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We constructed a genetic risk score (GRS) for HR using summary-level data in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) AVC Consortium to investigate if there was evidence in favor of a causal relation. AVC was present in 39% of FHS Offspring cohort participants and in 13% of MESA cohort participants. In multivariate adjusted models, participants in the highest resting HR quartiles had significantly greater prevalence of AVC, with a prevalence ratio of 1.19 (95% confidence interval [CI] 0.99 to 1.44) for the FHS Offspring cohort and 1.32 (95% CI 1.12 to 1.63) for the MESA cohort, compared with those in the lowest quartile. There was a similar increase in the prevalence of AVC per standard deviation increase in resting HR in both FHS Offspring (prevalence ratio 1.08, 95% CI 1.01 to 1.15) and MESA (1.10, 95% CI 1.03 to 1.17). In contrast with these observational findings, a HR associated GRS was not significantly associated with AVC. Although our observational analysis indicates that a higher resting HR is associated with AVC, our genetic results do not support a causal relation. Unmeasured environmental and/or lifestyle factors associated with both increased resting HR and AVC that are not fully explained by covariates in our observational models may account for the association between resting HR and AVC.

Background: There is limited information regarding genetic contributions to atherosclerotic aortic calcification, an important predictor of cardiovascular disease. Methods: We conducted a genome-wide association study (GWAS) meta-analysis with subsequent replication analysis to define single nucleotide polymorphisms (SNPs) associated with abdominal (AAC) or thoracic aortic calcification (TAC). AAC and TAC were quantified using multi-detector computed tomography. SNPs were assayed by Illumina or Affymetrix arrays and imputation at the cohort level was performed using data from the 1000 Genomes project. Results: 9417 individuals of European descent from four cohorts of the Cohorts for Heart and Aging Research in Genome Epidemiology (CHARGE) consortium were included in the AAC discovery analysis and 8422 individuals from five cohorts in the TAC discovery analysis. SNPs achieving genome-wide significance were tested for replication in four additional cohorts with Hispanic-American (HA) and African-American (AA) participants. Two regions contained SNPs associated at a genome-wide level for AAC (p-8 , Table), the HDAC9 (chromosome 7, 6 SNPs) and RAP1GAP (chromosome 1, 2 SNPs) genetic loci. All six HDAC9 SNPs were associated with AAC in HA. Among these, rs2107595 was associated with AAC both in HA (p=2.8x10 -6 ) and in AA (p=0.01). SNPs in RAP1GAP were not associated with AAC in the replication analysis. No SNPs were associated with TAC at the genome-wide threshold. SNPs in the HDAC9 locus were associated with other forms of calcification (coronary artery calcification) as well as clinically apparent coronary heart disease (pHDAC9 locus are associated with the presence of AAC in participants of European descent. This association was replicated in other ethnic groups in the United States. These findings suggest a novel role for HDAC9 in the development of abdominal aortic calcification.