Simple ultrasound parameters-carotid plaque and coronary Doppler velocity at rest- predict cardiovascular events better than clinical risk factors: the PENSIAMOCI-PRIMA screening study.

Background

Early detection of coronary artery disease (CAD) through non-invasive comprehensive cardiovascular ultrasound in asymptomatic subjects represents an opportunity to concentrate maximal preventive therapy on higher-risk individuals.

Objectives

This study aims to assess the potential incremental value of an innovative but simple cardiac/carotid ultrasound (CCU) screening protocol for predicting outcome in asymptomatic individuals. CCU is based on the assessment of carotid plaques, myocardial global longitudinal strain (LV GLS) and Doppler coronary flow velocity in the mid tract of the left anterior descending coronary artery (V-LAD) at rest.

Methods

This prospective, observational, single-center study enrolled asymptomatic apparently healthy volunteers. Clinical data, blood tests, treadmill ECG and standard echocardiography data were collected on top of CCU variables. The primary combined end point was the occurrence during follow-up of a) hospital admission for acute coronary syndrome or angina (in this case requiring confirmatory CT detection of at least 50% coronary stenosis or an abnormal functional cardiac imaging test), b) cardiovascular death, c) hospital admission for heart failure, d) hospital admission for atrial fibrillation, e) elective coronary revascularization procedure. A secondary end point, corresponding to the primary end point without the e) component (coronary revascularization procedure), which is potentially increased in subjects with abnormal screening results (work-up bias) was also analysed to confirm robustness of the associations.

Results

We enrolled 1033 subjects (median age 59 years, 50% females). During a mean follow-up of 23 months, 150 primary combined endpoints (and 84 secondary end points) were recorded. In the overall population the mean mid-tract V-LAD was 41.5cm/sec, mean LV GLS was -20.6% and 327 subjects (32%) had a carotid plaque detected. Figure shows the Receiver Operating Curves (ROC) for both the primary and secondary end points based on V-LAD. Table shows the multivariable analysis of clinical and imaging variables for the association with the secondary end point. Only age, the presence of at least one carotid plaque, and V-LAD remained significant. While the analyses were conducted using continuous variables, the best V-LAD cut-off for the prediction of either primary or secondary end points resulted > 44cm/sec; using this cutoff, abnormal V-LAD was present in 274 subjects (26.5%), while 759 (73.5%) had normal V-LAD.

Conclusions

A simple, low-cost, ultrasound screening strategy is capable to predict combined cardiac outcome significantly better than comprehensive evaluation of clinical risk factors and standard echocardiography variables.

Twenty-four percent of study subjects who on initial screening showed increased V-LAD (274 subjects), i.e. higher than 44cm/sec, had a secondary end point over a mean 23-month follow-up, versus 2% of subjects showing normal V-LAD.Figure ROC curve V-LAD velocity vs endpointsTable Multivariable association with endpoint