Israel Medical Association Journal

Background: Hypertension is considered resistant if blood pressure cannot be reduced to <140/90 mmHg with an appropriate triple-drug regimen, including an oral diuretic, with all agents administered at maximal dosages. This definition has evolved with the development of new therapies and evidence-based data supporting treatment to lower BP[1] goals.

Objective: To assess whether vitamin C and atorvastatin improve endothelial function and blood pressure control in subjects with resistant arterial hypertension and dyslipidemia.

Methods: Forty-eight hyperlipidemic subjects with RH[2] (office systolic BP >140 mmHg and/or office diastolic BP >90 mm/Hg notwithstanding antihypertensive treatment with three medications in maximal doses) were randomized into three groups to receive additional medication for 8 weeks. Group VTC (n = 17) – mean 24 hour SBP[3] 150.6 ± 5.2 mmHg, DBP[4] 86.1 ± 3.3 mmHg, low density lipoprotein 158.1 ± 24.5 mg/dl) – received vitamin C 500 mg per day; Group ATR (n = 15) – mean 24 hour SBP 153.1 ± 4.8 mmHg, DBP 87.1 ± 6.7 mmHg, LDL[5] 162.6 ± 13.6 mg/dl) – received atorvastatin 20 mg/day; and Group PLA (n = 16) – mean 24 hour SBP 151.1 ± 7.4 mmHg, DBP 84.8 ± 5.9 mmHg, LDL 156.7 ± 26.1 mg/dl – received a placebo. High resolution ultrasound was used to calculate brachial artery flow-mediated dilation, and 24 hour ambulatory BP monitoring was performed at study entry and after 8 weeks.

Results: In the ATR group there were significant reductions of SBP (DSBP1-2: 13.7 ± 5.6 mmHg, P < 0.001), DBP (DDBP1-2: 7.8 ± 5.7 mmHg, P < 0.01), LDL (DLDL1-2: 67.7 ± 28.3 mg/dl, P < 0.001) and improvement of brachial artery FMD[6] (DFMD2-1: 4.2 ± 2.6%). No significant changes in BP, LDL and FMD were observed in the other two groups.

Conclusions: In subjects with RH and dyslipidemia, atorvastatin 20 mg/day compared to vitamin C 500 mg/day may help to achieve better BP control and improve endothelial function in a finite period. A larger trial is needed to assess the drug's efficacy in this population for longer periods.

Background: Primary aldosteronism is a common cause of non-renal secondary hypertension. A correct diagnosis results in curing the hypertension or targeting appropriate pharmacotherapy. In patients with low renin resistant hypertension (after treatment with three or more different anti-hypertensive drugs the blood pressure remains above 140/90 mmHg), screening for aldosteronism is mandatory.

Objectives: To demonstrate that normal blood levels of potassium in resistant hypertensive patients do not exclude the possible presence of hyperaldosteronism, and to suggest the use of the plasma aldosterone concentration (ng/dl)/plasma renin activity (ng/ml/hour) ratio in screening for hyperaldosteronism.

Methods: Blood tests, suppression and stimulation tests (2 L normal saline IV/4 hours and 20 mg furosemide IV for 60 minutes in a standing position) were systematically performed in 20 low renin normokalemic resistant hypertensive patients. None had renal disorders, known endocrine abnormalities or heart failure. They did not receive anti-hypertensive drugs affecting PAC[1] or PRA[2]. Basal PRA and PAC were measured twice: PAC after saline infusion and PAC/PRA after stimulation.

Results:. PAC/PRA above 50 was used to denote hyperaldosteronism. Serum K was 4 ± 0.07 mM/L, PAC 22.8 ± 1.8 ng/dl, PRA 0.13 ± 0.02 ng/ml/hour, PAC/PRA 190 ± 22 (above 100 in 17). After suppression PAC decreased from 25 ± 1.8 to 11 ± 1 ng/dl (normal <5 ng/dl). Stimulation did not affect PRA and PAC/PRA. Abdominal computed tomography scan revealed normal adrenal glands in 15 patients. Spironolactone (116 ± 60 mg/day) normalized blood pressure in all patients; it was used as a single therapy in 8, and in association with only one anti-hypertensive drug in the remaining 12 patients. In one patient the treatment was discontinued due to the presence of hyperkalemia.

Conclusions: Low renin resistant hypertension associated with normokalemia may be due to hyperaldosteronism. Normal aldosterone levels in the basal condition do not exclude the possibility of hyperaldosteronism. Using a PAC/PRA ratio above 50 as a screening test can aid the physician in deciding when to perform dynamic tests, thus increasing the sensitivity of the diagnosis of hyperaldosteronism. CT scan is frequently normal. Targeted pharmacotherapy leads to a normalization of blood values.