For a patient with rest pain and an ankle pressure of >300mmHg, what can be concluded about the result?

The conclusion drawn from an ankle pressure measurement greater than 300 mmHg in a patient experiencing rest pain points to the likelihood of an erroneous reading, particularly due to arterial calcification. In patients with significant vascular disease, such as those with diabetes or chronic renal failure, arterial walls can become calcified, making them rigid. This rigidity can lead to falsely elevated blood pressure readings on non-invasive tests like the ankle-brachial index (ABI).

When the arteries are calcified, the compliance of the vessel is reduced, which means that the pressure measured does not accurately reflect the true state of blood flow or the severity of the arterial occlusion. Instead, a high ankle pressure reading in such cases does not reliably indicate adequate vascular supply or the presence of critical arterial disease. Therefore, recognizing calcification as a factor that can skew results is crucial in interpreting ankle pressures effectively in the context of vascular health.