Abstract Body: Objectives
Carotid intima-media thickness (CIMT) is reflective of arterial aging and injury. However, there are inconsistencies in the reported associations between CIMT measurements and CVD risk, specifically mean versus maximum CIMT, the role of carotid plaque location and quantity. This study explores the associations of these measures in older adults.
Design
A longitudinal analysis of data from the British Regional Heart Study, a prospective cohort study
Participants
1315 men aged 71-92 years, without baseline coronary heart disease (CHD) or stroke
Methods
Between 2010-2012, participants underwent follow-up, comprising of questionnaires, physical examination, and blood tests. CIMT and carotid plaque characteristics (location and quantity) were assessed using ultrasound. Cox proportional hazards models estimated multivariate-adjusted hazard ratios (HR) for incident CHD and stroke (fatal/non-fatal), based on CIMT and plaque features.
Results
Over a median follow-up of 10.2 years, 108 incident CHD cases and 110 incident stroke cases (fatal/non-fatal) occurred. After adjusting for confounders (age, social class, smoking, exercise, alcohol intake, BMI, medications, comorbidities, blood pressure, cholesterol, CRP and NT-pro BNP), no significant associations were found between mean or maximum CIMT and CHD or stroke events (fatal/non-fatal). However, both mean and maximum CIMT were significantly associated with fatal CHD events (HR 1.38, CI 1.07-1.76 and HR 1.30, CI 1.02-1.61, respectively per standard deviation increase in CIMT). No significant association was observed with fatal stroke events. Stroke risk increased with increasing number of carotid plaques (HR 1.29, CI 1.04-1.61) which was seen for both fatal and non-fatal strokes. No association was seen with CHD. When examined by plaque location, plaques located in the common carotid artery (CCA) was associated with incident stroke events (HR 1.73, CI 1.06-2.83) and to a lesser extent with CHD (HR 1.48, CI 0.9-2.43). No associations were seen for other sites.
Conclusion
In older men, mean and maximum CIMT are more associated with fatal CHD events than with non-fatal CHD. No significant association was found between CIMT (mean or maximum) and incident stroke events. However, the presence of carotid plaques, particularly in the CCA and in greater quantities, is strongly associated with an increased risk of stroke (fatal/non-fatal). These findings suggest that CVD risk varies according to measures of CIMT in older men.