Impact of Cardiovascular Risk Factors and Pharmacologic Treatments on Carotid Intraplaque Neovascularization Detected by Contrast-Enhanced Ultrasound

Background: Neovascularization is a marker of plaque vulnerability that can be assessed noninvasively using contrast-enhanced ultrasound (CEUS). The presence and extent of plaque neovascularization and their relation to cardiovascular risk factors and treatments were assessed in asymptomatic patients with carotid stenosis of intermediate severity and no indication for revascularization. Methods: Sixty-six patients aged 69 ± 8 years (59% men) were prospectively enrolled. Plaque neovascularization was assessed using CEUS with sulfur hexafluoride contrast in each of the four carotid segments bilaterally (a total of 528 segments). In each plaque, the presence or absence of contrast enhancement was assessed semiquantitatively as CEUS grade 1 (no signal or signal confined to the adventitia and/or shoulder of the plaque) or CEUS grade 2 (signal within the plaque). Results: Plaques were detectable in 289 of 528 carotid segments (54.7%). CEUS grade 2 was present in at least one plaque in 48 of 66 patients (72.7%) and was not influenced by stenosis severity or morphology. The highest CEUS grade 2 prevalence was observed in patients with diabetes and the lowest in those treated with angiotensin-converting enzyme inhibitors and statins, especially when low-density lipoprotein cholesterol was <100 mg/dL. Patients with multiple CEUS grade 2 plaques (20 of 66 [30%]) had both higher low-density lipoprotein and higher C-reactive protein. Conclusion: Intraplaque neovascularization is frequent in asymptomatic patients with intermediate carotid stenosis and is more prevalent in those with diabetes. Low-density lipoprotein cholesterol < 100 mg/dL and treatment with angiotensin-converting enzyme inhibitors seem to confer protection from neovascularization, although larger interventional studies are necessary to confirm these data.