To the Editor A recent Review provided practical information about resistant hypertension. One point that may merit clarification is how the differing US and European diagnostic thresholds should be translated into decisions about renal denervation. The Review noted that US guidance defines resistant hypertension as office blood pressure of 130/80 mm Hg or greater, whereas European guidelines define it as 140/90 mm Hg or greater, with different ambulatory thresholds as well. Yet the sham-controlled renal denervation evidence summarized in the Review is derived largely from trials enrolling patients at or above the higher threshold; in the cited meta-analysis, 9 of 10 trials required office blood pressure of at least 140/90 mm Hg, and only 4 explicitly required a diagnosis of resistant hypertension. Could the authors clarify whether the renal denervation branch in their treatment algorithm is intended to apply to patients who meet the lower US definition alone or primarily to patients whose blood pressure profile resembles that of the device trial populations? A more explicit linkage between diagnostic definitions and the populations studied in renal denervation trials would help clinicians judge referral timing without overstating the current evidence base.