Prediction of fatal and non-fatal cardiovascular events in young and middle-aged healthy workers: The IberScore model

Our primary objective was to improve risk assessment for fatal and non-fatal cardiovascular events in a working population, mostly young and healthy.

We conducted a prospective cohort study to derive a survival model to predict fatal and non-fatal 10-year cardiovascular risk. We recruited 992,523 workers, free of diagnosed cardiovascular disease at entry, over six years, from 2004-2009. We divided the sample into two independent cohorts: a derivation one (626,515 workers; from 2004-2006) and a temporal validation one (366,008 workers; over 2007-2009). Then, we followed both cohorts over 10 years and registered all fatal and non-fatal cardiovascular events. We built a new risk calculator using an estimation of cardiovascular biological age as a predictor and named it IberScore. There were remarkable differences between this new model and Systematic Coronary Risk Evaluation (SCORE) (in both the specification and the equation).

Over the 10-year follow-up, we found 3762 first cardiovascular events (6‰) in the derivation cohort. Most of them (80.3%) were non-fatal ischaemic events. If we had been able to use our model at the beginning of the study, we had classified in the 'high-risk' or 'very high-risk' groups 82% of those who suffered a cardiovascular event during the follow-up. All the post-estimation tests showed superior performance (true positive rate: 81.8% vs 11.8%), higher discrimination power and better clinical utility (standardised net benefit: 58% vs 13%) for IberScore when compared to SCORE.

Risk assessment of fatal and non-fatal cardiovascular events in young and healthy workers was improved when compared to the previously used model (SCORE). The latter was not reliable to predict cardiovascular risk in our sample. The new model showed superior clinical utility and provided four useful measures for risk assessment. We gained valuable insight into cardiovascular ageing and its predictors.