Background: We sought to examine the differential impact of carotid artery stenosis (CAS) on the risk of all-cause mortality and major adverse coronary and cerebrovascular events (MACCE) in patients with vs. those without preexistent coronary artery disease (CAD) as defined by coronary angiography.
Methods: We conducted a follow-up survey of 1,390 patients who underwent non-emergent coronary angiography and same day carotid ultrasound and Doppler study, between January 2007 and May 2009. Follow-up was performed by means of investigator initiated telephone interviews and hospital records. Follow-up time was defined as the time period between the coronary angiography and either the date of death, MACCE, or the survey date.
Results: Of the 1,391 patients included in the study, angiographic CAD was present in 1,105 patients (79%). Mean and median follow up was 1,574 and 1,702 days, respectively. The occurrence rates of the primary composite MACCE, MI, and coronary revascularization during follow-up were higher among patients with CAD compared to those without CAD (48% vs. 20%, HR=2.1, p<0.001; 10% vs. 2%, HR=3.3, p=0.02; 36% vs. 8%, HR=4.6, p< 0.001; respectively), whereas the rates of all-cause mortality (10 % vs. 9 %, HR=0.94, p=0.81) and stroke (7% vs. 5%, HR=0.67, p=0.3) did not differ significantly between both groups. By multivariate analysis, the presence of CAS defined by 50% luminal stenosis was independently predictive of all-cause mortality and trended toward an independent association with the composite MACCE outcome among patients without CAD (HR=3.08, 95% CI 1.03-9.1, p=0.04; HR=2.13, 95% CI 0.9-4.9, p=0.08; respectively), however was not associated with this outcome among patients with CAD. CAS of any degree was not independently associated with any of the outcome measures in patients either with or without CAD.
Conclusions: The prognostic implications of CAS are predominantly imparted in the absence of preexistent CAD verified by angiography.
