Sodium is a known regulator of blood pressure. Sodium concentrations are sensed by macula densa cells in the kidneys.[1] When the blood sodium concentration increases, these cells activate the renin-angiotensin-aldosterone system, as shown below.
In short, increased salt intake causes your body to hold onto more water, which increases blood pressure. This extra pressure places a strain on your cardiovascular system which can eventually lead to worse cardiovascular disease outcomes over time.