Prevalence, Clinical Characteristics and Treatment of Bulgarian Patients With Resistant Hypertension

We conducted an observational, retrospective, non-interventional study. As a first step, we consecutively screened 4340 patients for HTN. Screening included patients hospitalized at our clinic with various cardiovascular pathologies/diagnoses from 1 July 2018, to 27 March 2024. We identified HTN in 3762 (86.7%) of all patients. In the next step, the hypertensive population was screened for resistant HTN using criteria recommended by the 2018 European Society of Cardiology (ESC)/European Society of Hypertension (ESH) Guidelines and 2023 ESH Guidelines for the management of arterial hypertension. Inclusion criteria for our study were as follows: (1) age ≥ 18 years; (2) an established diagnosis of "Arterial hypertension" according to the 2018 ESC/ESH Guidelines and/or 2023 ESH Guidelines for the diagnosis and treatment of this disease; (3) maintenance of office SBP ≥ 140 mmHg and/or office DBP ≥ 90 mmHg after ≥1 month of treatment with optimal or best-tolerated doses of three or more drugs, including a thiazide/thiazide-like diuretic, an RAAS blocker (either an angiotensin-converting enzyme inhibitor (ACEi) or an angiotensin II receptor blocker (ARB)), and a calcium channel blocker (CCB); (4) uncontrolled HTN confirmed by 24-h Holter-BP monitoring; (5) good adherence to the prescribed treatment (≥80% of the treatment period); and (6) patient agreement and signed informed consent at hospital admission to participate in all planned physical, instrumental, and laboratory investigations. Exclusion criteria for the study were as follows: (1) patients with HTN at target BP values achieved using ≤3 antihypertensive drugs; (2) patients with uncontrolled HTN using ≥3 drugs, but not at optimal doses or not including ACEi/ARB + CCB + thiazide/thiazide-like diuretic or a treatment period of \<1 month; (3) an established diagnosis of "secondary HTN"; (4) suspected/confirmed pseudo-resistant HTN; and (5) patient clinical condition and/or comorbid factors/diseases making the planned instrumental investigations unfeasible. After applying these criteria, we identified 128 patients with resistant HTN, representing 2.9% of all cardiovascular patients (n = 4340) screened and 3.4% of the hypertensive population (n = 3762) in our study. Of the patients with resistant HTN, 63 (49.2%) were male, and 65 (50.8%) were female (p = 0.860). The median age was 58.0 years, with an interquartile range (IQR) of 46.0-69.0 years. In the third step, we used propensity score matching to match 128 hospitalized hypertensives with controlled HTN.