Losartan May Not Prevent Vestibular Schwannoma Growth or Related Hearing Loss During Observation.

Objective: To evaluate the impact of losartan on vestibular schwannoma (VS) growth and related hearing loss during observation.

Study Design: Retrospective cohort study.

Setting: Tertiary referral center.

Patients: Sporadic VS patients undergoing initial observation with at least two magnetic resonance imaging and audiologic examinations.

Intervention: Losartan.

Main Outcome Measures: Endpoints included VS growth, quantitative audiologic changes, survival free of tumor growth, and survival free of nonserviceable hearing. Patient characteristics and endpoints were compared by losartan use.

Results: Seventy-nine patients were included, of which 33% were taking losartan. Tumor growth was observed in 50% of patients in the losartan group and 36% in the non-losartan group (p = 0.329). Survival analysis failed to show a significant difference in the hazard rate of VS growth between groups (hazard ratio, 1.38; 95% confidence interval, 0.70-2.70; p = 0.346). Throughout observation, mean decreases in normalized pure-tone average were 5.5 and 9.3 dB in the losartan and non-losartan groups, respectively (p = 0.908). Mean decreases in normalized word recognition score were 11.0 and 16.6% in the losartan and non-losartan groups, respectively (p = 0.757). Nonserviceable hearing developed in 19% of patients in the losartan group and 28% in the non-losartan group (p = 0.734). Survival analysis did not demonstrate a significant difference in the hazard rate of developing nonserviceable hearing between groups (hazard ratio, 1.71; 95% confidence interval, 0.56-5.21; p = 0.337).

Conclusions: Losartan use may not reduce the risk of VS growth or hearing loss during observation. A randomized trial would be ideal to further identify the true effect on growth and hearing.