The formation of plaques in human blood vessels, known as atherosclerosis, represents one of the major causes of death worldwide. Synthetic molecular communication (MC), in combination with nanotechnology, is envisioned to enable novel approaches toward diagnosing, monitoring, and treating diseases. In this paper, we propose an investigation of the effects of plaque formation on the human blood vessel as an MC channel. By characterizing these changes, the early detection of plaques using MC networks in the human circulatory system could become possible. We model a simplified blood flow scenario in a human carotid artery using OpenFOAM. Nanoparticles are released in the bloodstream in front of a region obstructed by a plaque, and their transport and distribution are evaluated as they pass through. The results are obtained for different plaque sizes and channel lengths. We observe a significant impact of a growing plaque on the channel characteristics in terms of a reduced propagation delay and a decrease in the cumulative number of received particles due to particles trapped by the plaque. Therefore, the receiver could detect abnormalities from a change in these channel conditions over time. Further investigation of these methods in conjunction with more realistic modeling of the channel and communication nodes will be necessary to confirm the results. It could contribute towards advanced future methods of diagnosis.