Introduction Increased carotid intima-media thickness (IMT) and the presence of carotid plaques are both considered surrogate markers of atherosclerosis. Although inter-related, these two phenotypes represent heterogenous pathophysiological processes. Increased IMT is largely correlated to normal ageing and blood pressure, whereas plaques are synonymous with established atherosclerosis. We sought to determine the distinct relationships of carotid intima-media thickness and carotid plaque disease with quantitative parameters of left ventricular (LV) function.
Methods We studied 2279 healthy subjects recruited from the LOLIPOP (London Life Sciences Prospective Population) study free of clinical cardiovascular disease. Bilateral carotid ultrasonography was performed on all subjects to determine presence of carotid plaque, with the total number of plaques identified providing a plaque score. Subjects with a plaque score of 0, 1–2, 3–5 and > 5 were classified as having no, mild, moderate and severe plaque burden respectively. Tissue Doppler imaging was performed on all subjects for derivation of parameters of LV longitudinal function and filling pressure (myocardial Sa velocity, myocardial Ea velocity and the E/Ea ratio).
Results Subjects with higher plaque score were older, more likely to be male, have a greater prevalence of hypertension, diabetes and history of cigarette smoking (all p<0.001). A severe plaque burden was associated with attenuated Sa velocity compared to those without plaques, and increasing plaque burden was associated with reduced Ea velocity and increased LV filling pressure in a dose-dependent manner (Abstract 111 Figure 1). After multivariate regression analysis (ANCOVA) for age, gender, race, blood pressure, antihypertensive therapy, diabetes, body mass index and LV mass, the presence of severe plaque burden remained independently associated with attenuated Sa velocity (p=0.003), attenuated Ea velocity (p=0.007) and increased E/Ea ratio (p=0.009). Increased IMT was independently associated with Ea velocity, but not with either Sa velocity or E/Ea ratio.
- left ventricular function
- population studies