A genetic risk score predicts recurrent events after myocardial infarction in young adults

To evaluate whether a genetic risk score (GRS) improves prediction of recurrent events in young nondiabetic patients presenting with an acute myocardial infarction (AMI) and identifies a more aggressive form of atherosclerosis.

We conducted a prospective study with consecutive nondiabetic patients aged <55 years presenting with AMI. We performed a genetic test, cardiac computed tomography, and analyzed several biomarkers. We studied the association of a GRS composed of 11 genetic variants and a primary composite endpoint (cardiovascular mortality, a recurrent event, and cardiac hospitalization).

A total of 81 patients were studied and followed up for a median of 4.1 years. There were 24 recurrent cardiovascular events. Compared with the general population, study participants had a higher prevalence of 9 out of 11 risk alleles. The GRS was significantly associated with recurrent cardiovascular events, especially when baseline low-density lipoprotein cholesterol (LDL-C) levels were elevated. Compared with the low-risk GRS tertile, the multivariate-adjusted HR for recurrences was 10.2 (95%CI, 1.1-100.3; P=.04) for the intermediate-risk group and was 20.7 (2.4-181.0; P=.006) for the high-risk group when LDL-C was≥2.8mmol/L (≥ 110mg/dL). Inclusion of the GRS improved the C-statistic (ΔC-statistic=0.086), cNRI (continuous net reclassification improvement) (30%), and the IDI (integrated discrimination improvement) index (0.05). Cardiac computed tomography frequently detected coronary calcified atherosclerosis but had limited value for prediction of recurrences. No association was observed between metalloproteinases, GRS and recurrences.

A multilocus GRS may identify individuals at increased risk of long-term recurrences among young nondiabetic patients with AMI and improve clinical risk stratification models, particularly among patients with high baseline LDL-C levels.