[Spanish Society of Hypertension position statement on the 2017 ACC/AHA hypertension guidelines]

The American College of Cardiology (ACC) and the American Heart Association (AHA) have recently published their guidelines for the prevention, detection, evaluation, and management of hypertension in adults. The most controversial issue is the classification threshold at 130/80mmHg, which will allow a large number of patients to be diagnosed as hypertensive who were previously considered normotensive. Blood pressure (BP) is considered normal (<120mmHg systolic and <80mmHg diastolic), elevated (120-129 and <80mmHg), stage 1 (130-139 or 80-89mmHg), and stage 2 (≥140 or ≥90mmHg). Out-of-office BP measurements are recommended to confirm the diagnosis of hypertension and for titration of BP-lowering medication. In management, cardiovascular risk would be determinant since those with grade 1 hypertension and an estimated 10-year risk of atherosclerotic cardiovascular disease ≥10%, and those with cardiovascular disease, chronic kidney disease and/or diabetes will require pharmacological treatment, the rest being susceptible to non-pharmacological treatment up to the 140/90mmHg threshold. These recommendations would allow patients with level 1 hypertension and high atherosclerotic cardiovascular disease to benefit from pharmacological therapies and all patients could also benefit from improved non-pharmacological therapies. However, this approach should be cautious because inadequate BP measurement and/or lack of systematic atherosclerotic cardiovascular disease calculation could lead to overestimation in diagnosing hypertension and to overtreatment. Guidelines are recommendations, not impositions, and the management of hypertension should be individualized, based on clinical decisions, preferences of the patients, and an adequate balance between benefits and risks.

[An evaluation of the control of antihypertensive treatment by using ambulatory arterial pressure monitoring]

BACKGROUND

Outpatient monitoring of blood pressure (OPMBP) allows more precise values to be obtained and to observe the oscillations over 24 hours. Although this is widely used in the estimation of the antihypertensive efficacy of drugs, few studies have been performed on the evaluation of the control in treated patients.

METHODS

One hundred eight patients (M/F 55/53, mean age 50 +/- 11 years, body mass index 29.7 +/- 4.4) with essential high blood pressure (HBP) were included in the study fulfilling the criteria of: a) DBP > 95 mmHg on 3 visits over a 2 month period, b) antihypertensive treatment maintained over 2 months and c) normal renal function (Cr < 115 mumol/l). Twenty-five patients were considered as having resistant HBP on presenting BP > 150/100 mmHg during the course of treatment with well combined and adequately dosed drugs, one of which was a diuretic. Twenty-four hour OPMBP was carried out in all the patients on a normal work day with a SpaceLabs 90202 monitor. Acceptable control was considered when the mean of the DBP throughout the day (08:00-22:00) was < 85 mmHg.

RESULTS

Out of all the patients studied, 67 (62%) showed acceptable control and 27 (25%) showed normotensive values. Among the 25 refractory hypertensive patients 20 (40%) showed an acceptable control and 7 (28%) normotensive values. The only clinical difference between both groups was the presence of a greater degree of organic repercussion in the inadequately controlled group (chi 2 p < 0.05). Eight patients showed medium values of SBP over 24 h < 120 mmHg and 2 medium values of DBP over 24 h < 70 mmHg.

CONCLUSIONS

Outpatient monitoring of blood pressure may be useful in the evaluation of the control of high blood pressure in patients submitted to pharmacologic treatment who do not present an adequate reduction in the values of blood pressure.

Effects of adrenolytic drugs on the antihypertensive action of beta-blocking agents in the acute neurogenic hypertensive dog

1. The antihypertensive action of three beta-blocking agents (dl-propranolol, dl-atenolol and butoxamine) was studied before and after pretreatment with adrenolytic drugs (reserpine and guanethidine) in acute neurogenic hypertensive (sino-aortic denervated) anesthetized dogs. 2. High doses of reserpine (2 mg/kg s.c.) suppressed both the effects of sino-aortic denervation and the antihypertensive action of dl-propranolol (1 mg/kg i.v.) 3. Pretreatment with reserpine (1 mg/kg i.p.) or guanethidine (15 mg/kg i.v.) delayed the manifestation of the antihypertensive action of dl-propranolol (1 mg/kg) observed in untreated (control) animals. 4. In a similar way, both dl-atenolol (1 mg/kg i.v.) and butoxamine (1 mg/kg i.v.) lost their antihypertensive effects after reserpinization. 5. These results indicate that the antihypertensive action of the three studied beta-blocking agents seen in debuffered animals depends upon the integrity of peripheral sympathetic nervous system under our experimental conditions. These effects are compatible with the view that beta-adrenoceptor blocking agents may exert, at least partly, their antihypertensive action through blockade of peripheral beta prejunctional adrenoceptors.

Potentiation by naloxone of pressor reflexes

1 The effect of intravenous naloxone, and opiate antagonist, was studied on the pressor responses elicited by stimulation of afferent nerves (vagus and laryngeal superior nerves) in anaesthetized dogs. 2 Although naloxone (0.1 mg/kg i.v.) alone failed to modify basic blood pressure, the pressor responses induced by stimulation of either the vagus or laryngeal nerve were potentiated by naloxone. 3 Morphine (0.2 mg/kg i.v.) suppressed these two cardiovascular responses. These depressor effects of morphine were reversed by subsequent injection of naloxone (0.1 mg/kg i.v.). 4 The results suggest the involvement of endogenous opiate peptides in pressor reflexes elicited by stimulation of the afferent nerves.