Left ventricular hypertrophy and function in high, normal, and low-renin forms of essential hypertension
To assess the relative importance of the level of blood pressure (BP) and renin profile status as determinants of hypertensive left ventricular hypertrophy (LVH) and dysfunction, we studied, by quantitative echocardiography, 118 hypertensive patients off medication. The 19 high-renin patients were younger (31 +/- 13 years; p less than 0.01) but had hypertension of severity (152 +/- 13/95 +/- 11 mg Hg) similar to the 79 normal-renin patients (42 +/- 14 years; 152 +/- 17/98 +/- 12 mg Hg) and 20 low-renin patients (49 +/- 13 yrs; 157 +/- 17/95 +/- 11 mm Hg). Left ventricular (LV) mass index (normal = 70 +/- 25 g/m2) was similar in the high- (113 +/- 21 g/m2, p less than 0.001), normal = (114 +/- 31 g/m2, p less than 0.001), and low-renin patients (115 +/- 18 g/m2, p less than 0.01). End-diastolic relative wall thickness (nl = 0.32 +/- 0.05) was equally elevated in high- (0.41 +/- 0.09), normal (0.42 +/- 0.08) and low-renin groups (0.41 +/- 0.08) (all p less than 0.001). In the entire population, there was a closer correlation of relative wall thickness with total peripheral resistance (r = 0.54, p less than 0.001) than with mean blood pressure (r = 0.31, p less than 0.05). LV dysfunction (LV fractional systolic shortening less than 26%) occurred only in two high-renin patients, whereas LV fractional shortening was significantly increased in the low-renin subgroup (p less than 0.01). We conclude that the degree of LVH is similar in low-, normal-, and high-renin hypertensives and is proportional to the degree of hypertension, even though the high-renin patients were significantly younger; but that the low-renin patients with similar level of blood pressure, even though significantly older and with a longer duration of hypertension than the other patient groups, manifest increased LV function compared to normals.