Chronic Q fever prosthetic valve endocarditis — an important cause of prosthetic valve dysfunction in Australia
An 86-year-old man, a retired structural engineer, was referred to our tertiary centre with a 3-week history of New York Heart Association Class III–IV heart failure symptoms. Past medical history included bioprosthetic aortic valve (23 mm Perimount) implanted 10 years previously for severe aortic stenosis due to age-related degeneration, ischaemic heart disease (coronary artery bypass grafting in 2003), chronic kidney disease stage 2, dyslipidaemia, and previous smoking. He had been closely followed by his local cardiologist with slowly progressive dysfunction of the aortic valve replacement, thought to represent prosthetic valve degeneration, which was asymptomatic and managed conservatively. Importantly, there were no symptoms or clinical suspicion of chronic endocarditis. A sudden clinical deterioration, with clinical signs of left ventricular failure, prompted a referral to hospital.
On examination, the patient was haemodynamically stable and afebrile. There were no peripheral stigmata of infective endocarditis. His jugular venous pressure was raised at 5 cm, and he had lower limb pitting oedema. Bibasilar crackles were noted on chest auscultation, and there were murmurs consistent with mixed prosthetic valve stenosis and regurgitation. The patient’s abdomen was soft, with no evidence of hepatosplenomegaly.
Laboratory investigations showed a white blood cell count of….