A case report of infective endocarditis in a 52-year-old female with unrepaired tricuspid atresia and d-transposition of the great arteries

Abstract

Background

d-Transposition of the great arteries (d-TGA) is a congenital cardiac defect that is typically fatal. Those patients who survive without surgical repair and who are rare in number, need adequate intracardiac shunting and will suffer from chronic cyanosis. Here, we present a rare case of an adult with unrepaired cyanotic congenital heart disease (CHD) who developed infective endocarditis (IE) and also our approach to the medical decision-making process in this uncommonly encountered dilemma.

Case summary

A 52-year-old female with unrepaired d-TGA with tricuspid atresia, hypoplastic right ventricle, unrestricted atrial septal defect, ventricular septal defect, and sub-valvular as well as valvular pulmonic stenosis with a hypoplastic, bicuspid pulmonary valve presented with abdominal pain and hypoxia and was found to have an acute renal infarct. Transthoracic echocardiogram (TTE) revealed a large mobile mass on the mitral valve. Blood cultures grew Streptococcus mitis-oralis and she was diagnosed with streptococcal native mitral valve IE complicated by a renal embolus. Her large left-sided vegetation and embolic phenomenon favoured surgery. However, a right heart catheterization showed normal intracardiac pressures, likely a result of multi-level obstruction relating to sub-valvular and valvular pulmonary stenosis protecting the pulmonary vasculature from over-circulation and pulmonary hypertension. Cardiac surgery posed a significant risk of destabilizing her delicately balanced haemodynamics. Hence, she was treated with ceftriaxone for 4 weeks. A repeat TTE 8 weeks later showed a resolution of the vegetation.

Discussion

A decision for surgery vs. medical treatment for IE in adult patients with compensated CHD should be made following a multi-disciplinary assessment of each patient’s unique cardiac haemodynamics and after shared decision-making with the patient.

Introduction

Tricuspid atresia (TA) is a form of complex cyanotic congenital heart disease (CHD). Clinical features and survival are determined by the amounts of systemic and pulmonic blood flow. As such, TA is subclassified based on the relationship of the atretic valve to the great arteries. Type I TA has normal anatomy of the great arteries, but in Type II TA, the aorta and pulmonary artery (PA) are transposed [d-transposition of the great arteries (d-TGA)]. Nowadays, TA with d-TGA is typically detected antenatally with high detection rates and managed accordingly. Those patients who survive without surgical repair and who are rare in number need adequate intracardiac shunting and will suffer from chronic cyanosis. Here, we present a rare case of an adult with unrepaired cyanotic CHD from Type II TA with d-TGA who developed infective endocarditis (IE). We also discuss our approach to the medical decision-making process in this uncommonly encountered dilemma.

Timeline

Case presentation

A 52-year-old female presented with severe right upper quadrant abdominal pain without nausea, vomiting, diarrhoea, or dysuria. Two months prior to presentation, she had flu-like symptoms and completed a course of empiric doxycycline for bronchitis. Of note, she reported prior dental issues and no dental care in the past 2 years. After admission, imaging demonstrated an acute right renal infarct. Cerebral computed tomography was negative for mass or infarct, and she was subsequently anticoagulated with heparin. On examination, she was found hypotensive (blood pressure 90/54 mmHg) and afebrile, with a heart rate of 80 b.p.m. and hypoxia (SpO₂ of 79% on room air). A Grade 2 systolic ejection murmur was auscultated at the left upper sternal border. She had cyanotic fingers bilaterally, but no Osler nodes, Janeway lesions, or splinter haemorrhages. A dental exam revealed multiple carious root tips with the risk for infection. A laboratory analysis showed an elevated haemoglobin of 17.9 g/dL (reference range: 11.5–15.5 g/dL) and C-reactive protein of 2.2 mg/dL (reference normal value: <0.9 mg/dL). Lactate, white blood cell count, and creatinine were within reference ranges.

She had a history of unrepaired Type II TA with d-TGA, hypoplastic right ventricle (RV), unrestricted atrial septal defect (ASD), and ventricular septal defect (VSD) and sub-valvular as well as valvular pulmonic stenosis with a hypoplastic, bicuspid pulmonary valve (Figure 1, Supplementary material) She was diagnosed at birth and her parents opted for conservative management in childhood. Her baseline oxygen saturation levels were almost in the range of 77–79%. Two years prior to this hospitalization, she had an outpatient evaluation by our adult CHD team, at which time she was asymptomatic, working as a librarian, and able to conduct her activities of daily living without any significant limitations. She was struggling with poor dentition due to a lack of dental insurance, which she was actively attempting to acquire. Invasive cardiac testing was offered, but the patient deferred. The importance of oral hygiene and endocarditis prophylaxis were emphasized and the plan was to do a follow-up in 6 months with repeat non-invasive cardiovascular imaging and dental reassessment, but unfortunately, the patient was lost to follow-up until this hospitalization 2 years later. Her only home medication at this time was sertraline 100 mg twice daily.

Upon this presentation, cardiogenic vs. septic shock and an embolic event from either an intracardiac thrombus or endocarditis were part of the differential diagnosis. Blood cultures were drawn and empiric therapy with vancomycin was started. Transthoracic echocardiogram (TTE) showed a large (2 cm × 0.5 cm) mobile mass on the lateral annulus of the mitral valve adjacent to the posterior leaflet consistent with a vegetation. During diastole, there was prolapse of the mass through the valve into the ventricle (Figure 2A–D, supplementary material). Left ventricular systolic function was normal with an ejection fraction of 57%. No significant mitral stenosis or regurgitation were noted. Blood cultures grew Streptococcus mitis-oralis. She was diagnosed with streptococcal native mitral valve endocarditis complicated by renal embolus.

The patient had a large, left-sided vegetation complicated by embolic phenomenon which formed a surgical indication.¹ To assess her surgical risk and further define her haemodynamics, she underwent right heart catheterization which demonstrated normal filling pressures [right atrium (RA) 8 mmHg, left atrium (LA) 6 mmHg] and normal PA pressure (mPAP 16 mmHg). Given her unrepaired cyanotic CHD, cardiac surgery posed a significant risk of destabilization of her delicately balanced haemodynamics, as well as risk of stroke and renal injury. After a multi-disciplinary review of the patient’s case, conservative management was pursued.

Based on culture results, the antibiotic regimen was narrowed down to ceftriaxone. A repeat TTE 5 days after admission showed a decrease in the size of the vegetation and preserved mitral valve function (Figure 2E and F,Supplementary material). She was discharged home to complete a 4-week course of i.v. ceftriaxone via a peripherally inserted central catheter (PICC). Given her single ventricle physiology, air filters were placed on her PICC line to prevent air embolism. Follow-up appointments were scheduled for dental extractions to ensure infection source control. The patient was asked to take antibiotic prophylaxis (single 2 g dose of amoxicillin) before future dental procedures and also schedule routine cleanings.

The patient was readmitted 1 month after discharge for subjective fevers and diffuse body aches. Blood cultures were negative and a repeat TTE showed resolution of the mitral valve vegetation. No clear explanation was identified and her symptoms resolved prior to discharge. She has not had any recurrence of symptoms at follow-up 9 months after her initial presentation.

Discussion

Tricuspid atresia is defined as the congenital agenesis of the tricuspid valve. As a result, there is a lack of communication between the RA and RV resulting in right ventricular hypoplasia. The Type II subtype of TA is the one where the aorta and PA are transposed creating two distinct circulatory circuits where oxygenated and de-oxygenated blood do not mix. The incidence is estimated to be 3 per 10 000 live births, and if left uncorrected has a mortality rate of 90% within the first year of life.² Remarkably, our patient has survived into her 50s without surgical intervention. In her heart, de-oxygenated blood returns to the RA and oxygenated blood returns to the LA, which are connected by a large ASD. There is complete intracardiac mixing, and partially oxygenated blood is pumped across a VSD to the aorta, arising from the hypoplastic RV, and to the PA, arising from the left ventricle (LV) (Figure 1A–D). Due to multi-level obstruction related to sub-valvular and valvular pulmonary stenosis, the pulmonary vascular bed is ‘protected’ from over-circulation, thus preventing the otherwise-eventual development of pulmonary hypertension (Figure 1E and F). While echocardiography and cardiac catherization were primarily utilized to help us understand our patient’s anatomy and haemodynamics, cardiac magnetic resonance imaging could have also provided enhanced visualization and more details on ventricular volumes, arterial, venous, and valvular flows as well as myocardial fibrosis. Together, this information can further aid in presenting appropriate medical and surgical options to patients.

Surgical palliation for d-transposition of the great arteries

For patients with d-TGA and two functional ventricles, the arterial switch operation (ASO) is the current standard of treatment. The ASO involves the transection and relocation of the aorta and pulmonary arteries, thus restoring the flow of oxygenated and de-oxygenated blood to the correct circulation.³ Prior to the introduction of the ASO, the Mustard and Senning atrial switch procedures were performed to palliate patients with d-TGA. In both procedures, the systemic and pulmonary venous return are re-routed via an intra-atrial baffle such that the pulmonary veins flow into the sub-aortic RV and the vena cavas flow into the sub-pulmonary LV.³ The presence of TA and RV hypoplasia in our patient precluded her from being a candidate for these surgeries. For patients with Type II TA with d-TGA and only a single functional ventricle, such as our patient, palliation with Glenn and Fontan procedures is typically performed. The Glenn procedure involves connecting the distal superior vena cava directly to the PA, creating a direct circuit from superior venous flow into the pulmonary arteries without any connection to the heart.⁴ Complete bypass of the RV can be completed via the Fontan procedure, in which the blood returning through the inferior vena cava is routed to the PA, typically via intracardiac or extracardiac conduit. As the procedure disconnects the systemic venous return from the heart, there is no ventricle to ‘propel’ blood to the pulmonary arteries, and therefore, low PA pressure is required to ensure adequate pressure gradient for systemic venous return. The remaining single ventricle is then responsible only for pumping pulmonary venous return to the body.⁵ Our patient was considered for Fontan palliation in early adulthood, but her parents opted for conservative management.

Infective endocarditis in congenital heart disease

Adult patients with CHD are at a greater risk of developing IE, particularly on the right side of the heart. The rate of development of IE in these patients is 1.1 per 1000 patient-years, which is substantially higher than the general population.⁶ Based on a risk prediction model derived from the CONCOR national registry for adults with CHD, our patient’s calculated risk of developing IE at the age of 40 was 21% and at the age of 60 is 37%.⁶ A Streptococcus is the most common organism isolated in this CHD population, followed by Staphylococcus aureus.⁷

One of the main reasons our patient developed IE was the absence of primary prevention, which is essential in patients with CHD. Patients should be counselled to maintain good oral and cutaneous hygiene. Antibiotic prophylaxis for spontaneous IE is recommended for patients with risk factors for developing poor outcomes after procedures that have the potential to cause bacteraemia. These include patients who previously had IE, patients with prosthetic cardiac valves, prosthetic materials or devices used for intracardiac repair, and patients with uncorrected cyanotic heart disease.^1,8 High-risk procedures in this group of patients include dental extractions and procedure such as routine cleaning where there is a manipulation of the gingival and periapical regions of the teeth, cardiac surgery, and certain respiratory, gastrointestinal, or genitourinary procedures.

Certain patients presenting with left-sided native valve IE warrant surgical management. These include patients with IE causing heart failure, heart block, annular or aortic abscess, or destructive penetrating lesions, those with IE from S. aureus, fungal or other highly resistant organisms, or those who have persistent bacteraemia >5 days despite adequate antibiotic treatment.⁹ Additional indications, such as the ones seen in our patient, include the presence of embolization and mobile vegetation >10 mm in length. Despite the large size of our patient’s vegetation, and her presentation with embolic phenomenon, conservative management was pursued after extensive multi-disciplinary review due to her unique cardiac haemodynamics. Surgical repair of underlying CHD can reduce the risk of IE; however, the use of artificial valve substitutes can, in turn, increase the risk of IE.¹ Moreover, cardiac surgical repair as a form of secondary prevention to reduce risk of IE recurrence has not been systematically studied.

Tricuspid atresia is a congenital cardiac condition with high mortality if left unrepaired. Palliation with the Glenn and Fontan procedures is the most commonly pursued surgical option for patients with Type II TA with d-TGA and a functional single ventricle. Adults with CHD, especially with unrepaired cyanotic CHD, are at an increased risk of IE. The decision for surgery versus medical treatment for IE in adult patients with compensated CHD should be made following a multi-disciplinary assessment of each patient’s unique cardiac haemodynamics and shared decision-making with the patient.

Lead author biography

Dr Rehan Karmali is an Internal Medicine Resident Physician at the Cleveland Clinic Main Campus. Following completion of his Master’s Degree in Physiology from UCLA, he earned his medical degree from the Touro College of Osteopathic Medicine in New York. He is an aspiring cardiologist and interested in using imaging modalities such as echocardiography to highlight unique cardiovascular physiology. In his free time, Dr Karmali enjoys watching football, supports Liverpool FC and also enjoys spending time with his family.

Supplementary material

Supplementary material is available at European Heart Journal – Case Reports.

Acknowledgements

The authors acknowledge the efforts of all treatment teams at Cleveland Clinic who helped take care of this patient.

Slide sets: A fully edited slide set detailing this case and suitable for local presentation is available online as Supplementary data.

Consent: Written consent for submission and publication of this case report in its entirety has been obtained from the patient in accordance with COPE guidelines.

Funding: This work was supported by Cleveland Clinic Foundation, OH, USA.

Data availability

The data underlying this article are available in the article and in its online supplementary material.

References

Author notes