From flank pain to splenic abscess: a complex case of infective endocarditis with literature review

Abstract

Background

Infective endocarditis (IE) is a severe condition characterized by inflammation of the heart endocardium and valves, commonly caused by Gram-positive bacteria. Complications such as embolic phenomena and organ abscesses can arise, necessitating timely diagnosis and intervention.

Case presentation

We report the case of a 20-year-old female with a history of cerebral and splenic infarctions due to IE. The patient presented with left-sided flank pain, urinary burning, and fever. Examination revealed mitral and aortic valve involvement, splenomegaly, and neurological deficits. Despite initial antibiotic therapy, the patient developed a splenic abscess and drug-induced neutropenia. She required aortic valve replacement and was successfully managed with a multidisciplinary approach.

Conclusion

Multidisciplinary management, including timely surgical intervention and advanced imaging, is essential for favorable outcomes in IE patients. This case underscores the importance of early detection and tailored treatment strategies in managing severe complications associated with IE.

Background

Infectious endocarditis (IE) is characterized by inflammation of the heart endocardium and valves, which affects the integrity of the chambers. Gram-positive bacteria—streptococci, staphylococci, and enterococci—are responsible for the majority of IE cases, accounting for 80–90% [1]. IE pathogenesis involves initial endocardial damage and local fibrin and platelet adhesion, forming a sterile nidus subsequently infected by circulating microbes [2]. Microbial proliferation leads to cytokine release by adhering monocytes, endothelial cell activation promoting fibronectin deposition, and stimulation of the coagulation system, culminating in vegetation formation, a conducive environment for bacterial growth that is resistant to host immune responses [3].

IE manifests with various serious complications, affecting approximately 57% of patients, including congestive heart failure, periannular abscesses, systemic embolization, and neurological issues, contingent upon factors such as causative pathogens and treatment strategies. Splenic abscess is a well-known, but rare complication in IE. Splenic infarction is a common and usually benign condition. Approximately 5% of patients with splenic infarction develop splenic abscesses. Early detection of complications, often via transesophageal echocardiography, is pivotal because timely surgical intervention can enhance outcomes. However, the optimal management of complicated IE remains undefined, necessitating a tailored approach involving cardiologists and surgeons [4, 5].

This case report aims to explore the challenges and strategies in managing complicated IE, particularly focusing on the occurrence of splenic abscesses and the role of multidisciplinary teams in improving patient outcomes.

Case presentation

A 20-year-old female presented to Medical City Hospital at Al-Kalamoon Private University with left-sided flank pain and urinary burning for a week. She also experienced right hemiparesis the day before admission, accompanied by a fever of 40 °C, butwithout loss of consciousness, vomiting, or nausea. Her family history revealed consanguinity between parents, but no specific illnesses. Her past medical history included special needs due to brain injury from perinatal hypoxia, delayed psychomotor development, and mitral and aortic valve involvement four years ago (with artificial aortic valve placement one year ago). Her parents mentioned a dental clinic visit two weeks prior for dental treatment.

Upon examination, she was conscious and responsive. Vital signs were a pulse rate of 75 beats per minute, blood pressure of 140/70 mmHg, respiratory rate of 14 breaths per minute, and a temperature of 38.6 °C. Cardiac examination revealed clear systolic and diastolic murmurs at the mitral and left sternal borders. Abdominal examination revealed a soft, nontender abdomen with splenomegaly. Neurological examination revealed central facial nerve palsy on the right side and decreased muscle strength on the right side of the body, without signs of meningism.

Based on these findings, the physician ordered a chest X-ray, echo, and laboratory tests. Most laboratory results were within normal limits (see Table 1). The chest X-ray showed a normal heart size with mild basal pulmonary infiltrates (Fig. 1). Abdominal echo revealed hepatosplenomegaly. The cardiac echo indicated aortic valve insufficiency with leaflet thickening and suggested endocarditis in the aortic valve. Given the high suspicion of IE, the physician initiated direct antibiotic coverage with vancomycin, gentamicin, and ceftriaxone. Aspirin and ranitidine were also administered. On the third day, the patient developed decreased urine output, prompting the addition of furosemide. Magnetic resonance angiography (MRA) of the brain without contrast revealed left cerebral infarction with partial occlusion of the middle cerebral artery, leading to the discontinuation of aspirin therapy (see Fig. 2).

Table 1 Laboratory tests upon admission

Fig. 1

A simple chest X-ray shows mild infiltrates in the lung bases with scoliosis in the thoracic spine, while the heart appears in normal size

Fig. 2

The MRA showed left cerebral infarction with occlusion in the middle cerebral artery

On the sixth day, the patient complained of increased bowel movements, which progressed to watery mucoid diarrhea (4–5 times daily), raising suspicion of pseudomembranous colitis. Stool studies ruled out Clostridioides difficile infection, and metronidazole was initiated, resulting in clinical improvement. In the evening, she experienced sudden severe left ear pain without other symptoms. Gentamicin and vancomycin were discontinued after.

consultation with an ear, nose, and throat specialist. A contrast enhanced computed tomography (CT) of the abdomen and pelvis with contrast revealed splenic infarction and an early splenic abscess (Fig. 3). On the seventh day, her clinical examination was mostly unremarkable except for the appearance of new fungus on her tongue, for which nystatin was administered.

Fig. 3

The CT scan of the abdomen and pelvis images show splenic infarction with the beginning of abscess formation in the spleen

Blood cultures obtained 72 h after inoculation showed gram-positive cocci sensitive to ceftriaxone (++++). She remained in the hospital for approximately two weeks, and was discharged with the following treatment plan:

• Continue ranitidine for 5 days and receive intravenous ceftriaxonefor one month due to the possibility of a mycotic aneurysm and the presence of splenic infarction related to infectious emboli.

• Repeat MRA.

• Refer the patient to the cardiac surgery department for aortic valve replacement due to recurrent IE.

• Monitor splenic infarction with subsequent CT imaging.

• Weekly blood tests.

After one week, the patient returned for repeat blood tests, which revealed drug-induced neutropenia likely caused by ranitidine, with a lower possibility of ceftriaxone (white blood cells 1.5 × 10⁹/L & neutrophils 18%). Both ranitidine and ceftriaxone were discontinued and replaced with imipenem for three days, with daily monitoring of the WBCs. A month after starting antibiotic therapy and once the patient’s condition stabilized, a cardiac surgical procedure was performed. The procedure involved opening the chest and pericardium to access the aorta, where a mechanical prosthetic valve was successfully implanted, followed by wound closure. The patient has been under regular follow-up for 10 years without any complications (see Table 2).

Table 2 Timeline of events

Discussion

The process of microbial embolization in IE may lead to various complications associated with the size and location of vegetation. A study discusses a rare case of coronary embolization due to IE, highlighting the challenges in treatment and the critical nature of prompt diagnosis and intervention [6]. In our case, the patient developed a splenic abscess, a complication associated with a large vegetation and embolic phenomena. Another report presented a case of catheter-directed aspiration for vegetation in a high-risk surgical patient with tricuspid valve bacterial endocarditis, showing a less invasive yet effective treatment option, which can be crucial for poor surgical candidates [7]. It demonstrates significant reduction in vegetation size and associated complications. A detailed retrospective analysis provides insights into IE with large vegetation, underlining the high mortality risk and necessity for early surgical intervention [8]. This is particularly relevant to our patient, who required surgical intervention due to the large vegetation and associated complications.

A review explores the natural progression of cardiac vegetation, emphasizing the role of intravenous antibiotics and the need for early surgical intervention in high-risk patients [9]. This highlights that while antibiotics can partially resolve vegetation, surgery is often needed to prevent severe outcomes, as seen in our patient’s case. A study examined fungal endocarditis, which poses additional complications due to larger vegetation and higher embolization risk, underscoring the importance of prompt antifungal therapy and potential valve replacement to manage severe cases and improve patient outcomes [10]. This is relevant to our patient, who developed complications requiring comprehensive treatment, including antifungal therapy.Our patient had a left cerebral infarction, highlighting the risk of IE. Research has found that neurological complications are common in IE patients, with septic emboli being the most frequent [11]. This aligns with our findings, where the patient developed a cerebral infarction due to embolization.

It identifies antiplatelet usage and mitral valve vegetation as key risk factors, emphasizing the need for close monitoring and management to mitigate adverse outcomes. Another study emphasized the challenges and timing of valve surgery in IE patients with cerebrovascular complications, suggesting that early surgery may reduce in-hospital mortality [12]. Additional research has reported a high prevalence of cerebral neurological complications in left-sided IE [13]. One case report highlighted the necessity for clinicians to consider IE in patients with unexplained neurological symptoms and fever [14]. This is particularly relevant to our patient, who presented with neurological symptoms and fever, leading to the diagnosis of IE.

A book chapter discussed the epidemiology and clinical presentation, highlighting stroke as the most common neurological complication [15].

MRI of the brain in our patient showed a left cerebral infarction with partial occlusion of the middle cerebral artery, highlighting the crucial role of advanced imaging in diagnosing and managing IE complications. One study discusses the polymorphic clinical presentation of IE and highlighted the importance of cardiovascular imaging technologies [16]. Advanced imaging techniques such as echocardiography and MRI are critical for the accurate diagnosis and management of IE. Another review emphasizes the timing of surgical intervention, showing how early and precise imaging can lead to better surgical planning and patient outcomes [17]. Research focuses on molecular imaging techniques, such as 99mTc-HMPAO-SPECT/CT and 18 F-FDG PET/CT, which provide valuable insights into ongoing infections and support accurate diagnoses [18]. A comprehensive review of multimodality cardiac imaging discusses the benefits of combining various imaging techniques for early diagnosis and risk stratification [19]. Another paper outlined the advantages and limitations of different imaging methods, underscoring the necessity of echocardiography as the initial diagnostic tool, complemented by CT and nuclear techniques in specific scenarios [20].

In our case, the patient initially responded poorly to vancomycin and gentamicin owing to an adverse reaction, necessitating a switch to ceftriaxone, which was later adjusted owing to the development of drug-induced neutropenia. A previous study discussed the feasibility and clinical outcomes of oral step-down antibiotic therapy for IE, showing no significant differences in mortality compared to prolonged intravenous therapy, with fewer adverse events [21]. This suggests that oral antibiotics can be an effective alternative for reducing hospital stays and associated risks. A review emphasized the need for effective antimicrobial regimens with high resistance levels [22]. Another report advocated vancomycin-based regimens because of their efficacy in clinical and experimental models [23]. Research has evaluated the safety and efficacy of outpatient parenteral antibiotic therapy (OPAT), indicating low mortality and relapse rates, suggesting that OPAT is a viable option [24]. A study analyzed perioperative outcomes in IE patients with antibiotic-resistant strains, showing higher rates of postoperative complications but demonstrating the benefit of hyperthermic perfusion in reducing hospital mortality [25].

Our patient was referred for aortic valve replacement after stabilization with antibiotic therapy, highlighting the necessity of timely surgical intervention for managing recurrent IE. Research highlights the importance of complete hardware removal in cardiac implantable electronic device-related IE, noting that patient comorbidities influence long-term outcomes rather than the removal method [26]. A study reviewed a 10-year experience in a non-cardiovascular center and revealed a high prevalence of healthcare-associated endocarditis and significant 12-month mortality rates, particularly in patients with diabetes and reduced right ventricular function [27]. This underscores the importance of comprehensive follow-up care and management of comorbidities. A previous study investigated the impact of perivalvular involvement on surgical outcomes [28]. There was no significant difference in long-term survival between simple and complex IE cases, although chronic renal failure remained a risk factor for late mortality. A study evaluated long-term antibiotic therapy for patients who could not undergo the indicated surgery, suggesting that this strategy, including oral suppressive antibiotic treatment, may be viable under multidisciplinary care [29].

Studies on rare complications of IE have provided detailed case reports highlighting the diverse and severe manifestations of the disease. A case report discussed a mitro-aortic IE on a bicuspid aortic valve complicated by multiple systemic emboli, including ischemic stroke, splenic and renal infarctions, and mycotic aneurysms, emphasizing the complexity of extracardiac manifestations [30]. Another report presented a case of blood culture-negative IE with atypical dermatologic manifestations, including a rash progressing to painful ulcers that was ultimately diagnosed through skin biopsy and transesophageal echocardiography [31]. In another case report, an 85-year-old man with a history of aortic valve insufficiency developed multiple complications including endocarditis and septic shock, which ultimately led to his death despite intensive medical treatment. The patient’s condition was complicated by recent stroke and thumb necrosis, highlighting the severity of systemic infection and the challenges in managing such complex conditions in elderly patients [32]. Research has reported two cases of IE initially misdiagnosed as meningitis and cellulitis due to embolic complications, underscoring the diagnostic challenges posed by non-specific symptoms [33]. A study described a fatal case of IE presenting as bacterial meningitis, stressing the importance of considering IE in patients with neurologic deficits and fever, particularly when Staphylococcus aureus is isolated from cultures [34]. Finally, the use of artificial intelligence (AI) and machine learning (ML) models has shown promising results in improving diagnostic accuracy, risk stratification, and personalized therapies for IE patients. These advanced technologies have demonstrated high accuracy in predicting mortality, identifying high-risk patients, and enhancing post-surgical outcomes. However, the implementation of AI/ML in healthcare also raises concerns regarding data privacy and ethical considerations, highlighting the need for further research and validation to optimize patient care and healthcare delivery in the field of cardiovascular medicine [35].

Conclusions

This case highlights the complexity and multidisciplinary approach to complicated infectious endocarditis management. Despite initial challenges with antibiotics and drug-induced neutropenia development, timely adjustments and surgical intervention resulted in a satisfactory long-term term outcome for this patient, who had a history of splenic and cerebral infarctions secondary to IE. This patient’s case emphasizes the vital roles of advanced imaging modalities for prompt diagnosis and interdisciplinary teamwork for effective treatment.