Non-invasive endothelial function assessment using digital reactive hyperaemia correlates with three-dimensional intravascular ultrasound and virtual histology-derived plaque volume and plaque phenotype

BACKGROUND AND AIM

To study relationships between endothelial dysfunction (ED) and coronary atherosclerosis derived from intravascular ultrasound (IVUS) and virtual histology (VH).

METHODS

Endothelial dysfunction was examined by EndoPAT system (Itamar Medical) in 56 patients who underwent IVUS and VH (Volcano corp.). Reactive hyperaemia index (RHI) < 2 was used for definition of ED. IVUS sequences were divided into 5 mm-long non-overlapping and adjacent vessel segments. Plaque phenotype was determined for each frame and 5 mm vessel segment was labeled according to highest frame score (from 0 for "no lesion" to 5 for "thin cap fibroatheroma; TCFA").

RESULTS

IVUS-VH data were collected from 41 patients suitable for three-dimensional analysis. Patients with ED exhibited larger plaque burden than those without ED (0.46 ± 0.08 vs. 0.39 ± 0.07, p = 0.014), smaller lumen area (8.59 ± 2.19 vs. 11.90 ± 3.50, p = 0.016), higher plaque risk score (2.82 ± 1.18 vs. 1.84 ± 0.90, p = 0.012), and higher number of TCFA frames (0.36 ± 0.22 vs. 0.22 ± 0.16, p = 0.038). Relative amounts of fibrous tissue correlated positively with RHI (p = 0.034, r = 0.33). The numbers of fibroatheromas and calcified plaques correlated with RHI inversely (r = -0.34, p = 0.031 and r = -0.32, p = 0.044, respectively).

CONCLUSIONS

Endothelial dysfunction correlates with severity and phenotype of coronary lesions and can contribute to non-invasive detection of individuals with higher risk of cardiovascular events.

Utility of established cardiovascular disease risk score models for the 10-year prediction of disease outcomes in women

Cardiovascular disease (CVD) is a major cause of mortality globally. In absolute numbers, more women die from CVD than men do. CVD mortality risk differs between genders, reflecting the different distribution of modifiable risk factors and severity of CVD outcomes. This study reviews six established risk score models and their applicability to the female population. These models are assessed against two criteria: discrimination and calibration. Sensitivity, specificity and positive- and negative-predictive values are also examined. The risk score models are found to be limited in applicability, requiring recalibration beyond their study population. Relevant risk factors to predict CVD mortality for women, such as measures of obesity, physical activity, alcohol consumption, use of antihypertensive medication, chronic kidney disease and coronary artery calcium are generally not incorporated in these models.