A 28-year-old Cambodian man with a history of congenital heart disease presented with a 6-month history of increasing fatigue, night sweats, and weight loss. His surgical history included two Blalock-Taussig shunts, ventricular septal defect closure, and placement of a pulmonary valve conduit via a Rastelli procedure. Echocardiographic and cardiac computed tomographic studies revealed a vegetation in the pulmonary homograft. Blood cultures grew gram-negative rods that were eventually identified as Suttonella indologenes . The patient underwent a prolonged course of intravenous antibiotics, which was complicated by septic pulmonary embolism that clinically resolved. Bacterial endocarditis caused by aerobic gram-negative organisms is uncommon. The authors report the first case of S. indologenes endocarditis in a patient with complex congenital heart disease.
Case Presentation
A 28-year-old Cambodian man with complex congenital heart disease presented with a 6-month history of increasing fatigue, night sweats, and an unintentional 30-pound weight loss. The patient reported a history of congenital heart disease, including two Blalock-Taussig shunts placed 9 years of age and a subsequent surgical ventricular septal defect closure and placement of a pulmonary valve conduit via a Rastelli procedure. He denied illicit drug use and was on no medications. The physical exam was significant for a grade IV/VI holosystolic murmur, heard loudest at the right upper sternal border and a grade III/VI early diastolic murmur at the right upper sternal border.
Transthoracic echocardiography (TTE) and subsequent cardiac computed tomographic angiography revealed mesocardia, situs solitus, L-loop ventricle, and a Rastelli-type pulmonary valve conduit ( Figure 1 ). A 1.8 × 1.1 cm mobile echodensity was seen attached to the distal portion of the pulmonary homograft and was associated with increased systolic flow with peak velocity of 3 m/s and severe regurgitation on TTE. Transesophageal echocardiography and cardiac computed tomographic angiography demonstrated the previously seen mobile density as well as additional smaller echodensities attached the wall of the homograft ( Figure 2 , Videos 1 and 2 ). Given the patient’s symptoms, these findings were concerning for vegetations. The systemic (anatomic right) ventricle was moderately dilated with moderate systolic dysfunction, with an ejection fraction of 38.7%. The pulmonary (anatomic left) ventricle was mildly dilated with normal systolic function (ejection fraction, 55%). Also seen were moderate aortic regurgitation, mild pulmonary atrioventricular valve (mitral) regurgitation, mild to moderate systemic atrioventricular (tricuspid) regurgitation, and the prior ventricular septal defect repair with no residual leak. Four of four blood cultures grew gram-negative rods, later identified as Suttonella indologenes , susceptible to ampicillin and ceftriaxone. The patient received a 6-week course of intravenous ceftriaxone 2 g/day through a peripherally inserted central catheter, followed by a 12-week course of oral amoxicillin 875 mg twice a day. The patient was deemed at high risk for surgical intervention because of prior cardiac surgeries and was discharged upon improvement in his constitutional symptoms.
Ten days after discharge, the patient returned to the emergency room complaining of sudden onset of pleuritic right-sided chest pain. Computed tomography of the chest revealed a pulmonary embolism in the right lower lobe ( Figure 3 ). An ultrasound of the peripherally inserted central catheter line site showed no evidence of thrombosis. Repeat TTE demonstrated a marked decrease in the size of the mobile density in the pulmonary homograft, consistent with embolization of homograft vegetation. Repeat blood cultures were negative. The patient’s symptoms improved, and he was discharged home on hospital day 3. The patient is doing well 21 months after discharge and remains in New York Heart Association class I.
