Hypertensive left ventricular hypertrophy: a mechanistic approach to optimizing regression assessed by cardiovascular magnetic resonance

Objectives: Neuroendocrine activation may be an important adjunctive mechanism for left ventricular hypertrophy (LVH) development. Controversy exists to as to whether LVH regression occurs due to blood pressure (BP) reduction alone or if adjunctive mechanisms play a role. We planned to test the hypothesis that for a similar BP reduction, LVH regression would be greater using a drug combination selected specifically to reduce neuroendocrine activity compared with one that did not. Methods: Forty-two patients with hypertension and cardiovascular magnetic resonance (CMR) proven LVH were allocated to one of two equipotent antihypertensive regimens for 6 months. Treatments were chosen on the basis of opposing mechanistic actions on the renin angiotensin aldosterone system (RAAS) and the sympathetic nervous system (SNS); one arm inhibitory (valsartan and moxonidine), the other neutral (bendroflumethiazide and amlodipine). The primary end point was absolute reduction in CMR-determined left ventricular mass (LVM). Results: All BP indices were highly comparable at the start and end of the trial (P>0.6 between groups). BP was reduced (always P<0.0001) by 37/17 mmHg in the valsartan and moxonidine group and 38/19 mmHg in the bendroflumethiazide and amlodipine group. CMR quantified LVM was comparable between the two groups at baseline and decreased significantly in both treatment groups (P < 0.0001). Reduction in LVM was significantly greater in valsartan and moxonidine [-25.9g; 95% confidence interval (Cl) -31.6 to -20.2] compared with bendroflumethiazide and amlodipine (-18.3g; 23.3 to -13.4) (P<0.05). Conclusion: The magnitude of LVH regression achieved by inhibiting the RAAS and SNS neuroendocrine pathways is greater than that produced by comparable BP reduction alone. This supports the hypothesis that neuroendocrine mechanisms are important in the regression of LVH.