U-shaped association between serum uric acid concentration and mortality in hypertrophic cardiomyopathy patients

Background. No study has examined the effect of low serum uric acid (SUA) concentrations on mortality in hypertrophic cardiomyopathy (HCM) patients. The aim of the present study was to assess the relations between both low and high SUA concentrations and the risk of mortality across the full range of SUA concentrations in a retrospective cohort of HCM patients. Methods. A total of 454 HCM patients were enrolled in the study, and SUA concentrations were measured at baseline. The primary and secondary endpoints were all-cause mortality and HCM-related mortality, respectively. The associations between SUA concentrations and endpoints were analysed. Results. During a median follow-up of 3.8 years, there were 80 (17.6%) all-cause mortality events, and 52 of them (11.5%) were ascribed to HCM-related mortality. Patients with SUA concentrations of 250-350 mu mol/L had the lowest all-cause mortality rate (11.8%) and HCM-related mortality rate (5.0%). Both low and high SUA concentrations were associated with increased all-cause and HCM-related mortality. Adjusted HRs were 2.52 (95% CI 1.13-5.61, p = 0.024) and 4.86 (95% CI 1.74-13.58, p = 0.003) for all-cause mortality and HCM-related mortality in the lowest SUA group (<250 mu mol/L) when compared with the reference group (250-350 mu mol/L), respectively. The corresponding HRs in the highest SUA group (>= 450 mu mol/L) were 2.73 (95% CI 1.42-5.23, p = 0.003) and 4.14 (95% CI 1.70-10.13, p = 0.002), respectively. Conclusions. Both low and high SUA concentrations were significantly associated with increased risk of all-cause mortality and HCM-related mortality, which supported a U-shaped association between SUA concentrations and mortality in HCM patients.