Importance of central BP assessment in ISH of the young. Which devices are best suited for practical use?

Isolated systolic hypertension (ISH), defined as brachial systolic blood pressure (bSBP) ≥140 mmHg and diastolic blood pressure (DBP) <90 mmHg, is highly prevalent among young subjects and in the elderly. The prognostic significance of ISH in young individuals remains the object of large debate which might be solved, at least in part, if considering the prognostic role of central BP. For any given value of pBP, the cardiovascular (CV) risk is better defined by central BP (cBP). Young individuals with ISH have long been considered at low CV risk, given the assumption that a "spurious hypertension" phenotype characterized by elevated peripheral (brachial) BP (pBP), normal cBP, and elevated BP amplification was often found in this population. However, this remains to be proven, because many other studies found no differences in BP amplification between ISH and sisto-diastolic hypertension. Despite numerous attempts, methodologies for cBP assessment by non-invasive devices are currently not standardized. As a result, different devices could provide different cBP values despite using the same biological signals. Devices providing accurate estimates of BP amplification as a dimensionless ratio between amplitudes of central and peripheral arterial waveforms might be well suited for clinical purposes in young individuals with ISH. There is urgent need of well-designed prospective studies aiming at longitudinally evaluating the amount of CV risk associated with elevated cBP in young subjects with ISH and their related incremental prognostic value.