Abstract

INTRODUCTION

Resistant hypertension (RHT) is defined as high blood pressure despite three antihypertensive medications at best-tolerated doses. By definition, one of the drugs should be a diuretic. RHT is a common clinical problem and the exact prevalence of RHT is not known. As a subgroup, RHT has not been studied widely.. The present study has investigated RHT patient demographics and the N- terminal pro-brain natriuretic peptide (NT-proBNP) levels in a cardiology outpatient cohort.

METHODS

The outpatient data between 1st of January and 30th of June 2015 of 957 patients of ….. State hospital’s hypertension specialty clinic has been reviewed retrospectively. The patients with pseudo-RHT (treatment incompliance, inadequate drug doses, white-coat HT etc), seconder HT (chronic renal or renovascular diseae. etc) and reduced ejection fraction (EF) heart failure are excluded. Among 957 patients, 68 patients have been identified as true RHT with EF>50% and no moderate to severe cardiac valve regurgitation and renal dysfunction.

RESULTS

The cut-off levels of NT- proBNP were defined as 300pg/ml for patients younger than 75 years and 600 pg/ml for patients older than 75 years. Median NT-proBNP level was within normal limits in younger RHT patients (NT-proBNP = 175 pg/ml) whereas the median NT-proBNP was higher than cut-off in older RHT patients (NT-proBNP = 916 pg/ml, p=0.021).

DISCUSSION AND CONCLUSION

The current study suggests the underlying mechanism might be different in RHT according to age. Normal NT-proBNP levels exclude hypervolemia factor in younger patients. In this patient group, renal denervation therapy may be more beneficial because of the increased intrinsic sympathetic activity. RHT patients older than 75 years have higher levels of NT-proBNP but unfortunately the study group is not big enough to make a decision. Because of single-center results, retrospective design and limited number of patients, further studies are needed.