RESUMEN
This study compared the effects of 1 year of monotherapy with a calcium-channel antagonist (nilvadipine; NIL), an angiotensin-converting enzyme (ACE) inhibitor (temocapril; TEM), or a new vasodilator (cadralazine; CAD) on left ventricular (LV) hypertrophy in essential hypertension. Furthermore, to elucidate the mechanism responsible for regression of LV hypertrophy after treatment, LV mass index (LVMI) by echocardiography, plasma renin activity (PRA), aldosterone (PAC), norepinephrine, and atrial natriuretic peptide (ANP) concentration were measured before and after treatment. Thirty-six patients were randomly assigned to the NIL, TEM, or CAD groups. Blood pressure (BP) before treatment was 174 +/- 10/104 +/- 7, 173 +/- 18/103 +/- 8, and 171 +/- 16/103 +/- 7 mm Hg (mean +/- SD) in NIL, TEM, and CAD groups, respectively. BP was lower after treatment with each of the three test drugs than after the placebo period, and there were no differences in BP reduction among three groups. LVMI, in NIL and TEM, was reduced from 129 +/- 48 to 115 +/- 39 g/m2 and from 117 +/- 39 to 88 +/- 20 g/m2 (p < 0.05 and p < 0.01, respectively), whereas, in the CAD group, it was increased (110 +/- 30 to 138 +/- 27 g/m2; p < 0.01). In the CAD group, PAC decreased and ANP increased significantly. The change in LVMI correlated with that in BP for TEM and with that in ANP in all patients. These data indicated that LV volume overload as well as LV pressure overload may contribute to LV hypertrophy and that monotherapy with CAD is not desirable from the point of view of LV mass reduction in essential hypertension.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Hipertensión/tratamiento farmacológico , Hipertrofia Ventricular Izquierda/tratamiento farmacológico , Nifedipino/análogos & derivados , Vasodilatadores/uso terapéutico , Adulto , Anciano , Aldosterona/sangre , Factor Natriurético Atrial/sangre , Ecocardiografía , Femenino , Hemodinámica/efectos de los fármacos , Humanos , Hipertensión/patología , Masculino , Persona de Mediana Edad , Nifedipino/uso terapéutico , Norepinefrina/sangre , Piridazinas/efectos adversos , Piridazinas/uso terapéutico , Renina/sangre , Tiazepinas/uso terapéuticoRESUMEN
The objective of this study was to assess the regression of vascular structural changes seen in essential hypertension after long-term monotherapy with a calcium antagonist and to clarify the relations to cytosolic free calcium and neurohumoral factors. Blood pressure, minimal vascular resistance (MVR) by strain-gauge plethysmography, cytosolic free calcium in platelets ([Ca2+]i) by Quin 2 method, plasma renin activity (PRA) and plasma aldosterone concentration (PAC), plasma noradrenaline (PNA) and parathyroid hormone (PTH) were measured in 14 essential hypertensives during a placebo period and 2 and 6 months after anti-hypertensive treatment with nilvadipine. Blood pressure decreased from 174 +/- 10/104 +/- 8 mm Hg during the placebo period to 154 +/- 13/93 +/- 14 mm Hg 2 weeks after nilvadipine, and the hypotensive effects were found throughout the 6-month period. Although increased MVR seen in hypertensives did not change after 2 months (from 2.1 +/- 0.7 to 1.9 +/- 0.6 mm Hg/ml/min per 100 ml tissue (PRU), NS), MVR decreased significantly at 6 months (1.6 +/- 0.4, PRU, P < 0.05). Elevated [Ca2+]i seen in hypertensives during the placebo period decreased significantly 2 months after nilvadipine treatment (156 +/- 26 and 140 +/- 27 nM, P < 0.01). The changes in MVR were associated with those in [Ca2+]i 6 months after nilvadipine (r = 0.56, P < 0.05). However, the changes in MVR did not correlate with those in PRA, PAC, PNA or PTH.(ABSTRACT TRUNCATED AT 250 WORDS)