Title : Association of hyperuricemia with length of stay, hospital readmissions and in-hospital mortality in patients admitted with an acute heart failure exacerbation
Background: In acute congestive heart failure (CHF) management, uric acid levels increase with IV diuresis, but an acute therapeutic uric acid lowering was not found to decrease BNP levels or improve LV ejection fraction. Hyperuricemia (HU) has been noted associated with increased mortality in patients with chronic CHF. However, an association between HU and outcomes of acute CHF has not been well investigated.
Methods: To study association between HU and length of stay (LOS), hospital readmission(s) and in-hospital mortality in acute heart failure, we conducted a single tertiary academic medical center retrospective cohort study of 586 consecutive patients with known uric acid level. Acute heart failure diagnosis was ascertained according to the GWG-HF definitions. Uric acid values were divided in quartiles as less than 3.39 (UAQ1), 4-6.79 (UAQ2), 6.8-10.19 (UAQ3) and 10.2 mg/dL or above (UAQ4). The normal reference range for our laboratory is 3.6-8.0 mg/dL in males and 2.6-6.8 mg/dL in females.
Results: Of the study patients, 39% (226) were females, 68+/-15 years old, 40% (236) with history of diabetes, 70% (410) with treated hypertension, 47% (275) with history of CAD, and 37% (218) with history of chronic kidney disease (CKD), including those on hemodialysis. HU was not associated with increased prevalence of diabetes, hyperlipidemia, hypertension, or prior known CAD or CKD.
Uric acid levels were significantly increased in patients who expired (12.3+/-3.3 vs. 7.6+/-2.9 in survivors, p=0.004). Furthermore, there were strong trends towards longer LOS (UAQ1 7.8+/-7.9 vs. UAQ2 8.6+/-10.9 vs UAQ3 9.5+/-10.5 vs. UAQ4 8.5+/-6.3 days, p=0.7) and more frequent readmissions associated with increasing levels of uric acid (UAQ1 32%, UAQ2 31%, UAQ3 38%, UAQ4 47%, P=0.06).
Conclusions: In patients admitted with acute heart failure, elevated uric acid levels portend poor prognosis and are associated with increased mortality. Increased uric acid levels may also aid in identifying acute CHF patients who require increased hospital resource utilization by prolonging LOS and increasing re-admission rates.