Reply to letter: Reversibility of hypertension‐induced subclinical vascular changes: Do the new ACC/AHA 2017 blood pressure guidelines and heart rate changes make a difference?

The comment of Papaioannou et al1 on reinterpreting the results of our recent study by the new classification of hypertension recommended in the 2017 ACC/AHA guideline is thought‐provoking, and the authors would like to thank them for their letter. According to the new American guideline, patients with stage 1 hypertension (ie, systolic blood pressure between 130‐139 mm Hg, previously called “pre‐hypertension”2 or “high normal”3) should also benefit from pharmacological therapy complementing lifestyle changes, provided that they are at higher risk (eg, 10‐year cardiovascular risk ≥10%).4 At first sight, the lower systolic cut‐off value of 130 mm Hg could seem too strict; however, considering the continuous association between blood pressure and cardiovascular disease development, these patients are also at risk compared to subjects with optimal blood pressure values (<120/80 mm Hg). Although the 2018 ESC/ESH guideline did not implement this classification,5 it seems reasonable to raise awareness of the population to the possible consequences of even mild blood pressure elevations. Thus, pharmacological therapy may be considered in the “high normal” category if the cardiovascular risk is very high (eg, established coronary artery disease) as recommended by the new European guideline as well.5 Therefore, the two guidelines share similar recommendations from the clinical point of view; the difference between them is the labeling of patients and the nomenclature used to define categories.

Accordingly, our data also imply that better results in intima‐media thickness (IMT) reduction may be achieved when hypertension is treated at an earlier rather than a more advanced stage, as the reduction in IMT was more pronounced in patients with a mean blood pressure level below the median value at baseline.6 One could say that the milder the blood pressure elevation, the better the reversibility of target organ damage represented by IMT.

Regarding our study cohort, only three patients were recommended solely lifestyle changes without any drug therapy. It is unlikely that these patients were at high or very high risk as diabetic patients or those with any severe comorbidity had been excluded from the investigations. Still, in line with the new recommendations, pharmacological therapy could now be considered for these subjects based on individual risk stratification. The question whether this would have an impact on the outcomes assessed in our study (IMT, arterial stiffness, cognitive functions, hemodynamics, etc) remains hypothetical now, but long‐term follow‐up of these patients is planned, which will hopefully provide valuable information on these issues.

Apparently, it would be interesting to separately investigate the parameters of patients with “elevated blood pressure,” “stage 1 hypertension,” and so on. On the other hand, dividing our patient cohort into these sub‐categories would result in a significant reduction of sample size in each group and the analysis would probably lose its statistical power. Thus, we would rather keep this patient cohort undivided, while future studies with appropriate sample sizes are planned to target the adverse effects of hypertension ranging from mild through moderate elevations to more advanced stages.

Lately, the association between heart rate (HR) changes and pulse wave velocity (PWV) has been in the focus of several studies with controversial results.7 The study of Papaioannou et al demonstrated a significant relationship between HR and PWV in individuals with stiffer aortas.8 In our study, we aimed at evaluating whether blood pressure management could reverse the early vascular and cognitive changes. Thus, the relationship between HR and PWV was not assessed here, and we only reported HR changes during head‐up tilt table testing. Nevertheless, further investigations are necessary to clarify the influence of HR on PWV in hypertensive patients receiving antihypertensive therapy.

CONFLICT OF INTEREST

The authors report no relationships that could be construed as a conflict of interest.