LONDON – Gout is an independent risk factor for acute myocardial infarction, even among younger patients and those without cardiovascular risk factors, according to Dr. Chang-Fu Kuo, who presented a late-breaking report at the Annual European Congress of Rheumatology.
The risk for acute MI was 23% higher among gout patients than the general population, judging from an analysis of a large Taiwanese database. Among individuals aged 20-44 years old and those without additional cardiovascular risk factors, the risk of acute MI was increased by 59% and 76%, respectively, reported Dr. Kuo of Chang Gung Memorial Hospital, Taipei, Taiwan.
To investigate the risk of acute MI associated with gout, Dr. Kuo and colleagues analyzed the 2000 Taiwan National Health Insurance database, which is a representative sampling cohort of the general population. Specifically, the investigators compared rates of first hospital admission for acute MI among gout and nongout patients aged 20 years or older. Of the 704,503 individuals included in the cohort (mean age, 42.73 years), 26,566 were diagnosed and treated for gout in 1996-1999, Dr. Kuo said. Compared with the nongout patients, "the gout patients were significantly older, with a mean age of 55.4 years, and they were significantly more likely to have diabetes and hypertension," he said.
The investigators followed the cohort from January 2000 through December 2008, for a total of 5.6 million patient-years of follow-up. During this period, 3,718 patients were hospitalized for acute MI, including 463 patients with gout. Of these events, 299 were fatal, including 35 in gout patients, Dr. Kuo said. "The incidence of acute [MI] in gout patients was 2.20 per 1,000 patient years and was significantly higher than in nongout patients, which was 0.60," he said.
In the multivariate model adjusted for age, sex, diabetes, hypertension, coronary heart disease, stroke, and end-stage renal disease, the respective hazard ratios for all acute MI and nonfatal acute MI in gout patients were 1.23 and 1.26, Dr. Kuo reported. "In patients without cardiovascular risk factors, the hazard ratio for all acute [MI] was 1.84, and for nonfatal acute [MI] was 1.80," he said, and when assessed by age, the respective hazard ratios for gout patients aged 20-44 years, 45-59 years, and 60 years or older were 1.59, 1.24, and 1.11.
The multivariate model was not adjusted for hyperlipidemia, which has been associated with gout, Dr. Kuo said, acknowledging that elevated lipid levels could play an important role in the increased cardiovascular risks observed in the gout patients.
Although the increased risk of acute MI associated with gout has been previously reported, "the risk in younger patients and those with low risk profiles hasn’t previously been established," Dr. Kuo explained. The finding that gout is an independent risk factor for the occurrence of acute MI – particularly nonfatal acute MI – among young, low-risk patients suggests the need for "vigilant cardiovascular monitoring" of these patients, he stressed.
Dr. Kuo reported having no conflicts of interest to disclose.