Table 1.

Comparison of randomized studies using xanthine oxidase inhibition in heart failure.

Author	Heart failure Population	Xanthine oxidase inhibitor	Follow- up in weeks	Primary Outcome definition	Primary outcome result
Givertz et al. 2015	253 with SUA >9.5 mg/dl with one more high risk marker	Allopurinol 300–600 mg/day	24	Clinical status: Outcomes, medication change and patient global assessment.	13% improved in both allopurinol and placebo arms.
Greig et al. 2011	32 NYHA II–III	Allopurinol 300 mg/day	4	6-minute walk test and oxidative stress markers	No difference in 6-minute walk test and improved oxidative markers
Nasr et al. 2010	59 NYHA III–IV	Allopurinol 300 mg/day	36	Composite endpoint: Global cardiac function and mortality/morbidity	Allopurinol did not improve composite endpoint
Hare et al. 2008	405 with a median SUA of 7.8 mg/dl and NYHA III–IV	Oxypurinol 600 mg/day	24	Clinical status: Outcomes, medication change, patient global assessment or NYHA	43% improved in the oxypurinol arm compared to 45% in the placebo arm. Improved primary outcome in patients with higher uric acid levels
Cingolani et al. 2006	60 NYHA II–III	Oxypurinol 600 mg/day	4	Ejection fraction	4.7+/− 2.6 % higher EF between oxypurinol and placebo arms
Gavin et al. 2005	50 NYHA II–III	Allopurinol 300 mg/day	12	Exercise stress test and 6 minute walk test	No difference in exercise performance with a decrease in plasma BNP.

SUA: Serum uric acid, NYHA: New York Heart Association, EF: ejection fraction, BNP: Brain natriuretic peptide