Health Program for prEvention of cardiovascuLar disEases Based on a Risk screeNing Strategy With Ankle-brachial Index.

Mortality due to cardiovascular disease (CVD) in Spain accounted for 29% of all deaths (32% in women and 26% in men) in 2017. Out of those, 67% were related to a coronary or a cerebrovascular disease .

A key strategy in primary prevention of CVD is to use risk functions to individualize preventive interventions for each patient. The current CV risk-screening program in some regions of Spain, is based using an adapted Framingham scale, REGICOR's risk function, which is integrated in the primary care electronic health record. This risk function predicts the probability within 10 years of developing a coronary event. However, this function fails to identify patients that fall into low- or intermediate-risk level, and might develop a CV event in the up following 10 years.

Ankle-brachial index (ABI) is a simple, non-invasive and economic technique, which allows detecting peripheral arterial disease (PAD), and gives independent risk function information compared to other coronary risk functions. Even tough, between 13-27% of middle age population have an ABI ≤ 9, around 50-89% of them do not exhibit any symptoms. However, they hold higher mortality risk and CV events. Current clinical guidelines for PAD screening, have a limited level of evidence, and only recommend using ABI on patients aged 50-70, who have diabetes or are smokers, and patients older than 70 years old.

A new risk function, REASON, to assess CVD risk has been designed. This model has proven to improve predictive capacity of holding an ABI ≤ 0.9 on those patients aged 50-74 that are apparently free of CVD. Therefore, a strategy that combines the current CV risk estimation using REGICOR, and the prediction capacity of pathologic ABI with REASON, would allow detecting high-risk patients with a PAD screening program. It is possible that patients, who hold an ABI ≤ 0.9, even if being asymptomatic, will adopt physician's recommendations on healthy life habits and preventive treatment.

The aims of this study are:

• To assess the effectiveness and cost-utility of adding a screening program with ABI to the current strategy of CV risk detection to reduce the incidence of CVD and mortality from all causes in the population aged 50 to 74.
• To assess the effectiveness of adding a screening program with ABI to the current strategy of CV risk detection to improve cardiovascular risk factors in the population aged 50 to 74.