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Untreated gout can cause myocarditis by leaving urate crystals in the myocardium, a case study suggested.

The 49-year-old man, hospitalized because of dyspnea and edema of the lower limbs, had normal renal function but elevated levels of C-reactive protein, serum uric acid, troponin T, pro-B-type natriuretic peptide, and leukocyte counts on routine laboratory testing.

An echocardiogram revealed biventricular dilatation with a left ventricular ejection fraction (LVEF) of 30% and a right ventricular ejection fraction of 39%, as a group led by Andrea Frustaci, MD, of Sapienza University in Rome, reported in the .

It turns out that amorphous urate crystals had been deposited in the man's cardiomyocytes, potentially causing a strong inflammatory reaction and cell death.

"We identified monosodium urate crystals by histology, electron microscopy, and negative birefringence on exposure of a frozen myocardial sample to polarized light," Frustaci's team said.

"Many studies have found that hyperuricemia is associated with increased risk for coronary artery disease, , and sudden death. The mechanism for this association remains uncertain, and to the best of our knowledge myocardial damage from urate crystal deposition has not been reported," the group noted.

Gout is known to increase uric acid in the blood and lead to urate crystals being deposited in the joints, kidneys, and soft tissues. These crystals have also been reported in coronary vessels and cardiac valves, the authors said.

The patient had stopped taking the gout medications allopurinol and colchicine for several months before admission because of gastric discomfort and diarrhea.

"On the basis of our experience with this patient, we conclude that gout can cause myocarditis with cardiac dilatation, cardiac dysfunction, and heart failure, particularly in patients with tophaceous and untreated gout," Frustaci and colleagues wrote.

They reported that they went on to treat the patient with 4 weeks of allopurinol and prednisone, after which his cardiovascular condition improved and LVEF rose to 45%.

Colchicine was recently shown to reduce the risk of ischemic events among heart attack survivors in the COLCOT trial.

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