Fungal endocarditis: patients at risk and their treatment

Abstract

Fungal endocarditis is not rare. It usually develops in patients with abnormal or surgically traumatized hearts, to whose blood fungi have gained access, perhaps during temporary (often iatrogenic) impairment of host defences. Although the blood is cleared rapidly, the fungus can establish itself in the endocardium, where it grows slowly. Thus, clinical and laboratory procedures (including blood and urine cultures) that have permitted early diagnosis and treatment of bacterial endocarditis, are not reliable in early fungal endocarditis. Greater reliance must be placed on serological monitoring of patients who have had transient fungaemia and are at risk of endocarditis. The clinician must consider factors that enhance fungal proliferation and invasion and be cognizant of its dangers - even in the absence of clear signs of infection. Prophylactic measures should be employed to protect the patient at risk, including topical, oral and systemic use of appropriate antifungal agents. Early therapy, the extent and duration of which can be determined by (1) obtaining the MIC of transitory blood or urine isolates - which should not be ignored - and (2) monitoring serology, might eliminate early invaders of the endocardium. Sixty-four reported cures of fungal endocarditis caused by Candida, the most common fungal pathogen, are tabulated, 29 were of classic fungal endocarditis requiring surgery, 3 of whom were seen later by others as fatal recurrences. Those treated early (shortly after candidaemia was diagnosed - mostly in patients on treatment for bacterial endocarditis or after cardiac surgery) survived without need for surgical removal of vegetations or valve replacement. Despite strong suggestive evidence that the first 35 patients tabulated had fungal endocarditis, histological proof exists for only a few who had surgery.

Cures of endocarditis caused by other fungi are noted. Improved surgical and medical therapy has improved the prognosis even of patients with the far-advanced disease. However, development of classic fungal endocarditis has been reported one or more years after cardiac surgery and late recurrences after intensive therapy of fungal endocarditis, that had led to clinical recovery of 2 years or more, have been reported. Serological monitoring of vulnerable patients might alert the physician to recurrence early enough for efficacy of drug therapy, averting fatal outcome or the need for further surgery.