Infectious endocarditis is a sudden illness that causes rapid heart and extracardiac injury. Embolic material enters the arterial circulation and causes embolic events in 20-50% of patients. The brain is one of the most common sites of embolism that can potentially interfere with treatment options. Neurological complications are the symptom associated with a poor prognosis in 20% of cases (45% of deaths versus 24% in patients without these complications).
This is the case of a 63-year-old male patient who presents to the main stroke clinic. Multifocal signs and prior aortic valvuloplasty raised the suspicion of infective endocarditis and antimicrobial therapy was initiated despite an initial negative transthoracic echocardiography (TTE). Imaging revealed vascular lesions in several arterial regions of the brain, some with hemorrhagic transformation and multiple splenic and renal regions of infarction. Hemodynamic instability and acute pulmonary edema developed just before surgery. Transesophageal echocardiography (TEE) confirmed a typical picture of vegetation, conditioning severe aortic regurgitation and a perivalvar abscess with fistulization to the right ventricle. Both have recovered surgically. The immediate postoperative period was characterized by cardiogenic shock, but the patient progressed favorably when he was transferred to the hospital ward where he continued his motor recovery.
Early surgery is a mainstay in the treatment of infectious endocarditis, reducing embolic risk. Once done, neurologic embolization can worsen the prognosis and cast doubt on further deterioration or hemorrhagic conversion after cardiopulmonary bypass. The optimal time interval between ischemic stroke and surgery has not yet been determined, but recent data advocates early surgery that, if indicated, should not be delayed.
Most embolic events occur before admission, making presentation variable. Clinical suspicion is of great importance for the prompt initiation of antibiotic therapy and the avoidance of subsequent embolic events. TTE is a sensitive tool in the diagnosis of endocarditis, but a negative result does not preclude the diagnosis, especially when endocarditis is clinically expected. Imaging should be performed systematically over the course of the disease to detect new and relevant complications, always taking into account the higher sensitivity of TEE for detecting intracardiac complications.
Infectious endocarditis (IE) is a sudden disease that causes rapid cardiac and extracardiac injury when embolic material enters the arterial circulation. With an incidence of four to seven cases per 100,000 inhabitants  in developed countries it develops untreated to death. Medical history is variable depending on causative agent, pre-existing cardiac disease and embolic events occurring in 20-50% of patients.
The brain is one of the most common sites of embolism, especially in left-sided endocarditis. Neurological complications are the present symptom in 20% of cases, interfere with treatment options and are associated with a poor prognosis (45% of deaths vs. 24% in patients without these complications) [2,3]. Modified Duke criteria, including intracranial hemorrhage as a minor criterion, are helpful, but clinical judgment is necessary.
This is the case of a 63-year-old male patient who presented to the main stroke clinic whose multifocal signs and previous aortic valvuloplasty suggested the suspicion of infective endocarditis. Antimicrobial therapy was initiated despite an initial negative transthoracic echocardiography (TTE).
A 63-year-old man was admitted to a secondary hospital with sudden left hemiparesis, left leg hypoesthesia and right leg weakness, accompanied by fever, vomiting and diaphoresis. With a medical history of aortic valvuloplasty 15 years ago, the patient denied subsequent complications, symptoms of congestive heart failure (HF) or angina. On admission he presented a regular pulse of 94 bpm, no murmur, blood pressure of 114/75 mmHg, normal breath sounds, but was a polyp with respiratory alkalosis and decreased arterial oxygenation (oxygen partial pressure). [PaO2] of 63 mmHg on room air). Laboratory tests revealed a white blood cell count of 15,300/ml (86% polymorphonuclear cells), high c-reactive protein (CRP) level of 353 mg/dl, 77,000/ml platelets, serum creatinine level of 1.38 mg/dl and urinalysis indicating infection. CT scan of the head showed a focal hemorrhage filling the right postcentral sulcus, associated with hypodensity in the postcentral gyrus, consistent with ischemia or edema. An MRI scan was performed which revealed multiple punctate brain lesions in different vascular regions, indicating an embolic source, some with hemorrhagic transformation (Figure 1). Blood cultures were positive for methicillin-susceptible S. aureus (MSSA). Despite TTE not demonstrating any structure indicative of vegetation, antimicrobial therapy with flucloxacillin 12 g per day was initiated, assuming the frequent association between MSSA bacteremia and endocarditis.
Meanwhile, vascular manifestations were noted with Janeway lesions in the fingers of both hands and the plantar surfaces of the feet. At that time, the patient presented one major criterion by Duke’s criteria (two blood cultures positive for MSSA) and three minor criteria, including vascular manifestations, predisposing heart disease, and fever that persisted through the seventh day of antibiotics, despite a rapid decline in KRP. An abdominal CT scan was performed which revealed multiple splenic infarcts, the largest at 9 cm, as well as areas of renal infarction, the largest at 7 cm.
Echocardiography was repeated 16 days after admission using transesophageal approach. It revealed severe aortic valve insufficiency, a typical picture of vegetation adjacent to the annulus, and a perivalvar abscess with fistulization to the right ventricle. CT scan of the brain was repeated, showing the small ischemic lesions already identified and a new one, in the left anterior region, with no new signs of intracranial hemorrhage. At the time of arrival at our hospital, and 20 days after the first admission, the patient had already developed hemodynamic instability and acute pulmonary edema. Despite the infection starting to subside and the fever disappearing, heart failure and intracardiac abscess fistulas were an important indication for urgent heart surgery at the time. The perivalvar abscess and fistula formation were repaired and the aortic valve replaced using a biological prosthesis. The immediate postoperative period was characterized by cardiogenic shock in need of aminergic and vasopressor support, as well as renal failure without the need for renal replacement therapy. Despite this, hospitalization progressed favorably, the patient stayed in our ICU for 10 days before being transferred to the hospital ward where he continued his motor recovery after the stroke.
Early surgery is a mainstay in the treatment of infective endocarditis, especially in the presence of progressive HF and uncontrolled infection. Severe left valve regurgitation can lead to HF, the most common indication for surgery and present in 42-60% of native valve endocarditis .
Intracardiac complications can also result from uncontrolled infection, the definition of which is not fully established. Randomly defined as persistent positive cultures and fever after seven to 10 days of antibiotic treatment, it can cause locally progressive infection with abscess, pseudoaneurysms, and fistulas requiring immediate intervention. Embolic complications are a frequent reason for persistent fever and local infection, as the risk of embolization increases with vegetation size. Silent brain embolism occurs in up to 60% of cases with neurological symptoms in 15-30% of patients .
Once done, neurologic embolization can worsen the prognosis and cast doubt on further neurologic decline or hemorrhagic conversion after cardiopulmonary bypass. The optimal time interval between ischemic stroke and surgery has not yet been determined, but should not be delayed if indicated. If intracranial hemorrhage is nevertheless present, neurological deterioration is expected in approximately 33.3% of cases and surgery should generally be delayed for a month or more. [4,5]. The decision must be made individually, but recent data argues for prompt surgery, even in intracranial hemorrhage . In this clinical case, the patient’s neurological damage was not severe and the bleeding was limited to small hypointense foci, with no progression in subsequent preoperative evaluation. The surgery was life-saving in the face of heart failure and was performed 20 days after the first stroke. No further neurological deterioration occurred.
Most embolic events occur before admission, making presentation variable. Clinical suspicion is of great importance in the prompt initiation of antibiotic therapy and the avoidance of subsequent embolic events.
TTE is a sensitive and specific aid in the diagnosis of endocarditis, but a negative result does not preclude the diagnosis, especially when endocarditis is expected. Imaging should be performed systematically over the course of the disease to detect new and relevant complications, always being aware of the higher sensitivity of TEE for detecting intracardiac complications.