A 50-week double-blind randomized trial tested sacubitril-valsartan — a drug combo widely used in heart failure — in adults with nonobstructive hypertrophic cardiomyopathy (nHCM) and reduced exercise capacity. The primary goal was to see if the drug could boost peak oxygen uptake (pVO2), a key measure of exercise fitness. The result: no significant difference in pVO2 between the drug and placebo groups, despite near-perfect treatment compliance (96%) in both arms.

But the story doesn't end there. Patients on sacubitril-valsartan showed notable structural heart improvements — a 4.7 mm reduction in interventricular septal thickness and a 22.5 g/m² drop in left ventricular mass index. A composite score of cardiac parameters also improved significantly in the treatment group. Whether these structural changes translate into better long-term outcomes for nHCM patients remains an open question.

Key Takeaways:

• No improvement in peak VO2 (exercise capacity) was observed after 50 weeks of treatment
• Significant reductions in heart wall thickness and left ventricular mass index were observed in the treatment group
• Hypotension-related events were more frequent with sacubitril-valsartan; no deaths were reported
• Small sample size (40 patients) limits the ability to detect smaller effect sizes

Why it matters: nHCM is a common but under-treated form of hypertrophic cardiomyopathy with limited therapeutic options. While sacubitril-valsartan didn't hit its primary endpoint, its cardiac remodeling effects keep the door open for further investigation into whether structural benefits could yield meaningful clinical gains over time.