Uric acid is associated with cardiac death in patients with hypertrophic obstructive cardiomyopathy

BACKGROUND: The role of uric acid (UA) in survival of patients with hypertrophic obstructive cardiomyopathy (HOCM) has not been fully evaluated. This study aimed to determine whether UA could be an independent risk factor of cardiac death in patients with HOCM. METHODS: A total of 317 patients with HOCM, who were receiving conservative treatment in Fuwai Hospital from October 2009 to December 2014, all of them completed UA evaluations, were analyzed. Patients were divided into three groups according to the UA levels: Tertile 1 (≤ 318 μmol/L, n = 106), Tertile 2 (319 to 397 μmol/L, n = 105), and Tertile 3 (≥ 398 μmol/L, n = 106). RESULTS: During a median follow-up of 45 months, 29 cardiac deaths (9.1%) occurred, including 6 sudden cardiac deaths and 23 heart failure-related deaths. Cardiac death in Tertile 3 (n = 16, 55.2%) was significantly higher than in Tertile 1 (n = 6, 20.7%) and Tertile 2 (n = 7, 24.1%). In univariate model, UA level (continuous value) showed predictive value of cardiac death [hazard ratio (HR) = 1.006, 95% CI: 1.003−1.009,P = 0.009]. Univariate Cox survival analysis had shown a significant higher property of cardiac death in patients of Tertile 3 when compared with those of Tertile 1, but cardiac death in patients of Tertile 2 did not show significant prognositic value compared with those of Tertile 1 (HR = 3.927, 95% CI: 0.666−23.162,P = 0.131). UA was found to be an independent risk factor (HR = 1.005, 95% CI: 1.001−1.009,P = 0.009) of cardiac death in the multivariate regression analysis after the adjustment for age, body mass index, atrial fibrillation, hemoglobin, creatinine, high-sensitivity C-reactive protein, interventricular septum/left ventricular posterior wall ratio, left ventricular outflow tract and left ventricular ejection fraction. CONCLUSIONS: UA concentration was found to be independently associated with cardiac death in HOCM patients receiving conservative treatment. Randomized trials of UA-lowering agents for HOCM patients are warranted.