AbstractIntroduction: Infectiveendocarditis (IE) is a serious complication of injection drug use. Right-sidedIE encompasses 5-10% of all IE cases, with the majority involving the tricuspidvalve (TV). The predominant causal organism is Staphylococcus aureus.
Most cases of right-sided IE can besuccessfully treated with antibiotics, but approximately 5-16% require eventualsurgical intervention. Presentation of Case: We report the case of a 36-year-old female with active injectiondrug use who developed methicillin-sensitiveStaphylococcus aureus IE of the tricuspid valve. Due to pooradherence to medical therapy as a consequence of opioid addiction, she developedseptic emboli to the lungs and an abscess in the left main pulmonary artery. Discussion: Theselong-term potentially fatal, sequelae of incompletely treated IE requiresurgical intervention, as medical therapy is unlikely to be sufficient. Surgicalmanagement may involve TV replacement, pulmonary artery resection, andpneumonectomy. Prevention of these complications may have been achieved by concurrentopioid addiction therapy.
Conclusion: Anintravascular pulmonary artery abscess is a novel complication of advanced IEthat has not been previously reported. This complication likely arose due toincomplete IE treatment as a consequence of opioid addiction, highlighting theneed for concurrent addiction management. Intravenous antibiotic therapy islikely not adequate, and surgical intervention, including pulmonary arteryresection and pneumonectomy may be necessary. Introduction:Tricuspid valve infective endocarditis (TVIE) isa serious complication of injection drug use (IDU) with a mortality rate of10-15% and potential for further deadly complications 1-3. Staphylococcus aureus accounts for60-90% of cases of TVIE, with enterococci, streptococci, Pseudomonas, and HACEK organisms occurring less frequently 1,2,4.Most cases of TVIE are treated medically, with only approximately 4% of all IEsurgeries in North America for TVIE 5. Surgical treatment is indicated incases of persistent and refractory infection with difficult to eradicateorganisms i.e.
fungi 1,4. Additionally, large valve vegetations and septicpulmonary emboli are indications for operative management 1. We report thecase of a patient with a history of active IDU who developed methicillin-sensitive Staphylococcus aureus(MSSA) IE and Candida fungemia. After numerous unsuccessful attemptsto complete medical therapy, she subsequently developed septic pulmonary emboli,proximal lung abscesses, and an abscess in the left main pulmonary artery. Wehighlight the importance of concurrent treatment of opioid addiction withintravenous antibiotic therapy in patients with IDU and deep-seated infectionsto prevent long term complications, and review the literature to understandpotential surgical treatment of such sequelae.
Case Presentation:A 36-year-old Caucasian female with a history ofactive IV heroin use, anxiety, and depression presented to the emergency department(ED) with one week of chest pain and shortness of breath. A trans-thoracicechocardiogram revealed a 13 x 26 mm vegetation of the tricuspid valve (TV)with moderate tricuspid regurgitation. She was treated with IV vancomycin andcefepime, however left the hospital against medical advice (AMA) after one day,feeling that her pain was poorly controlled. She presented to the ED againwithin 24 hours with dyspnea and a productive cough. Chest x-ray revealed aright middle lobe infiltrate. Blood cultures were drawn and grew MSSA (Fig. 1),and she was admitted to the ICU on IV oxacillin. She completed one day oftherapy, once again leaving AMA.
She returned to the hospital one daylater with severe dyspnea. Imaging revealed new septic emboli in the lungfields (Fig. 2). The patient was admitted and completed an eight day course ofIV oxacillin. She was then discharged to a skilled nursing facility (SNF) witha PICC line for continued medical treatment with oxacillin. She eloped from theSNF after 12 days, returning to the ED for PICC removal. At that time she wasurged to stay for inpatient antibiotic therapy, but declined.
Before leavingthe ED she was given one dose IM ceftriaxone and a ten-day course of oraldicloxacillin. Three weeks later, she presented to anoutpatient appointment with confusion and weakness. Blood cultures grew Candidafamata, and the patient was urged to report to the ED for treatment. Shewas given one dose of caspofungin in the ED before leaving AMA. Blood culturesdrawn prior to administration of caspofungin subsequently grew Candidaparapsilosis, and the patient was again advised to return to the ED. Shewas hospitalized on IV oxacillin and fluconazole and began to complain ofsubsternal chest pain. During this admission, she was found injecting heroin inthe hospital bathroom and required a 1:1 sitter with restricted visitation;psychiatry was also consulted to evaluate capacity.
Blood cultures remainedpositive for MSSA throughout the hospital course, with no further growth ofCandida. Repeat chest x-ray during this admission showed multifocal airspaceopacities and continued cavitary lesions in the lung fields, improved fromprevious imaging. She left AMA after seven days, deemed after formalpsychiatric evaluation to have decision-making capacity.
One week later she presented to the ED again inextreme pain, and was found to be in septic shock. She was started on IVfluids, vancomycin, caspofungin, and ceftriaxone in the ED and admitted to thehospital where she began to complain of pleuritic chest pain. Chest x-raydepicted bilateral pleural effusions and a developing cavitary focus of theright lung apex. CT chest with IV contrast demonstrated multiple new solidcavitary lesions bilaterally, a left sided loculated effusion, and a 1.
8 cmfluid attenuation within the left perihilar lung surrounding a consolidation,suspicious for a septic intravascular pulmonary embolism with abscess formationin the left main pulmonary artery (Fig. 3). Trans-esophageal echocardiogramrevealed a 1.
9 x 1.5 x 1.5 cm multi-lobulated, highly mobile vegetation on theanterior leaflet of the TV with severe regurgitation and possible leafletperforation. Cardiothoracic surgery was eventually consultedfor potential surgical intervention, but the patient was considered a poorsurgical candidate due to her continued hemodynamic instability and history ofnon-compliance to therapy. A repeat chest CT was obtained which showed proximalright-sided lung abscesses and findings suspicious for additional emboli in thesegmental and subsegmental arteries of the right lower lobe. She was dischargedto a subacute nursing facility with a PICC line for six weeks of continuedmedical treatment on IV cefazolin.
Blood cultures remained negative for twoweeks prior to discharge. The patient completed her antibiotic course with onerelapse. Repeat imaging after completion of antibiotic therapy demonstrated alarge highly mobile vegetation of the tricuspid valve, unchanged in size fromprevious studies, with continued severe tricuspid regurgitation. Discussion:To our knowledge thisis the first reported case of an abscess in the left main pulmonary artery as acomplication of IE. The development of this abscess demonstrates the importanceof completion of intravenous antibiotic therapy and the necessity of addictionmanagement in promoting patient compliance. This patient repeatedly withdrewfrom medical therapy due to her heroin addiction and thus developed serious and life threatening complications of IE including TV perforation,septic emboli, and an arterial abscess.
TV repair/replacement is a well-studiedtreatment option for IE with the patient meeting criteria for stage D tricuspidregurgitation (symptomatic, severe TR) and published indications for TV surgery6. Studies have shown better peri-operative and event free survival with TVrepair as compared to replacement 1,8. Indications for replacement includesignificant leaflet tethering, distortion of the valve, ventriculardysfunction, or severe pulmonary hypertension.
This patient, with possible TVleaflet perforation, was likely more suitable for TV replacement 1,7,8.Additionally, practice guidelines state that patients with right sided IE areindicated for surgical intervention in cases of lack of response toantimicrobial therapy, sustained infection with difficult to treat organismsincluding fungi and multidrug resistant bacteria, TV vegetations > 20 mm,and recurrent pulmonary emboli despite antimicrobial therapy 1,9. However,guidelines also suggest that it may be reasonable to avoid surgery in rightsided IE in patients with a history of IDU 9. Septic emboli occur in approximately 13 to 44percent of patients with IE 10. Treatment of septic emboli involvesunderlying infection/source control in combination with antibiotic therapy 1,11.Complications of septic emboli include mycotic pulmonary aneurysms treated withcoil embolization, vascular obstruction treated with thrombectomy, andabscess/infarct of the lung lobes treated with surgical drainage and/orresection of the infarcted area 10-13. Intravascular abscesses have not been previouslyreported as a complication of IE.
At this point, medical therapy is unlikely tobe sufficient, and surgical treatment may be optimal. A related report studyinginfiltrative, non-small cell lung cancer has shown that resection and repair ofthe pulmonary artery followed by pneumonectomy using a temporary intra-arterialconduit technique is both feasible and safe, with acceptable post-operativemorbidity rates (complication rates of 52.2% and 5-yr survival of 50%) 14.This surgical technique has not been studied in patients with advanced IE, buthas potential for application to this case. Although surgical treatment options wereavailable, they were not pursued in this case due to the patient’s history ofnon-adherence to medical therapy. The patient’s disease course, complicated bycontinued heroin use at home and even in the hospital on two occasions, underscoresthe struggle of drug addiction.
Appropriate opioid addiction treatment maylikely have facilitated adherence to and completion of a long-term intravenousantibiotic regimen, preventing the development of catastrophic complications ofher disease. Research has shown that opioid use disorder can successfully bemanaged during and after acute hospitalizations with methadone, and treatment canhelp facilitate other inpatient care 15. An initial dose of 20-30 mg dailycan safely be started inpatient, and providers should encourage a long-termtreatment plan and arrange for transfer to a maintenance program afterdischarge. If methadone cannot be initiated due to underlying disease orconcern for interaction with CYP-450 inducers such as antiretrovirals,buprenorphine, a partial opioid agonist, can be used to manage acute withdrawalsymptoms, and can be continued outpatient 15.
Initiation of methadone therapyduring our patient’s first hospital admission would likely have prevented herprolonged disease course. Conclusion:The presented case demonstrates a novel and rarecomplication of infective endocarditis. The development of the pulmonary arteryabscess was likely due to poor adherence to medical therapy, highlighting theimportance of completion of antibiotic treatment. The patient’s inability tocomplete medical therapy, however, was a consequence of her heroin addiction,emphasizing the necessity for concurrent addiction treatment. The currentopioid crisis in the United States was recently named a public healthemergency, and this case highlights the urgent need for effective and long termaddiction management strategies to ensure compliance to medical therapy –including outpatient parenteral antibiotic therapy – and prevention ofpotentially fatal long-term sequelae.