- Question
- To determine whether the angiotensin II receptor blocker losartan reduces left ventricular hypertrophy and fibrosis in patients with hypertrophic cardiomyopathy.
- Design
- Single-centre, randomised, double-blind, placebo-controlled trial of 133 adult patients treated for 12 months. Allocation used a computer-based system, and patients and investigators were masked to treatment.
- Population
- Adults aged 18 years or older with obstructive or non-obstructive hypertrophic cardiomyopathy. Mean age was 52 years and 35% were women.
- Intervention
- Losartan 100 mg per day for 12 months (64 patients).
- Control
- Placebo for 12 months (69 patients).
- Primary outcome
- Change in left ventricular mass assessed by cardiac magnetic resonance imaging or CT after 12 months.
- Results
- There was no significant difference in the change in left ventricular mass between placebo and losartan (mean difference 1 g/m2, 95% CI -3 to 6; p=0.60). Systolic blood pressure fell only in the losartan group (from 127 to 121 mm Hg; p=0.0001), confirming drug compliance.
- Safety
- Two patients (2%), both in the placebo group, died of sudden cardiac death. In the losartan group there was one case each of angioedema, deterioration of renal function and hyperkalaemia. Treatment was well tolerated by patients with left ventricular outflow obstruction.
- Conclusion
- Losartan did not reduce left ventricular hypertrophy in hypertrophic cardiomyopathy, although it was safe.
- Why it matters
- The trial challenged the widely held view that angiotensin II receptor blockers reduce cardiac hypertrophy. It also suggested that losartan can be used for other indications in these patients, even with obstructive physiology.
Card generated automatically with AI from the abstract of the original publication and the trial registry; every figure was checked against those sources. It may contain errors: verify the data at the source before using it for clinical decisions.
Generated on October 15, 2026