Atypical case of infective endocarditis
- 1 Department of General Medicine, Malankara Orthodox Syrian Church Medical College and Hospital, Kolenchery, Kerala, India
- 2 Department of Cardiology, Malankara Orthodox Syrian Church Medical College and Hospital, Kolenchery, Kerala, India
- Correspondence to Dr Abraham M Ittyachen; abyliz@rediffmail.com
Abstract
A man in his late 40s presented to the emergency department with generalised tiredness and breathlessness. He was a known case of chronic obstructive pulmonary disease and also had a recent history of COVID-19. At arrival, he was in respiratory failure. Blood culture grew Streptococcus parasanguinis, a commensal gram-positive bacterium and a primary coloniser of the human oral cavity. Echocardiogram revealed the presence of a flail mitral valve with vegetation suggestive of infective endocarditis. Although biomarkers of inflammation/infection had improved, he continued to be in cardiac failure, and hence he underwent mitral valve replacement with a mechanical valve. This case is unique in many ways; the patient was young, had a history of COVID-19, had native valve infective endocarditis and presented with type 2 respiratory failure and not the usual ‘typical’ manifestations of infective endocarditis. He had refractory heart failure requiring early valve replacement. His blood culture grew S. parasanguinis, a rare cause for infective endocarditis.
Background
Infective endocarditis is a disease with a highly variable presentation. The clinical manifestations of the condition are often multisystemic, ranging from dermatological to ophthalmic, and cardiovascular to renal.1 But respiratory failure has rarely been described as a clinical presentation in the medical literature.
We present a case of infective endocarditis who presented with respiratory failure. The patient was young, had a history of COVID-19 and did not have the typical manifestations of endocarditis. The organism isolated Streptococcus parasanguinis happens to be a rare cause of infective endocarditis.
Case presentation
A man in his late 40s and a painter by profession presented to the emergency department with generalised tiredness and breathlessness of 5-day duration. At arrival, he was drowsy. His pulse rate was 98 beats/min, blood pressure 150/100 mm Hg in right upper limb in supine position, respiratory rate 16 breaths/min, jugular venous pressure was elevated and oxygen saturation was 86% in ambient air. Examination of the chest revealed the presence of bilateral basal rales. He was afebrile at the time of admission.
He was a chronic smoker (30 pack years) and a known case of chronic obstructive pulmonary disease (COPD). Six weeks prior to this admission, he had COVID-19 infection from which he had an unremarkable recovery. He also had a history of pulmonary tuberculosis, which was treated.
Investigations
Initial arterial blood gas analysis in the emergency department was suggestive of type 2 respiratory failure. There was an episode of supraventricular tachycardia in the emergency department, which was confirmed on the cardiac monitor (it was cardioverted). Anteroposterior view of the chest radiograph showed an apparent cardiomegaly with mild infiltrates bilaterally, predominantly in the perihilar areas (figure 1). The initial blood counts showed a neutrophilic leucocytosis (Hb 12 gm%, total white cell count 17.6×109/L, differential count N 66% L 27% M 4% E 3%). Pro-BNP (Brain Natriuretic Peptide)was 5290 pg/mL (reference range<300). CRP (C-reactive protein) was 37.7 mg/dL (reference range 0–9). Endotracheal secretions were negative for acid-fast bacilli or any other bacterial pathogen. Pneumocystis pneumonia and leptospirosis (a tropical infection endemic to the area) were also ruled out. An initial bedside echocardiogram revealed the presence of a flail mitral valve with moderate-to-severe mitral regurgitation, left atrium and left ventricle being dilated and a mild-to-moderate tricuspid regurgitation, and lung comets. A second echocardiogram done on day 6 (full study) showed a 0.6×0.3 cm echogenic structure attached to the tip of the anterior mitral leaflet (AML) suspicious for a vegetation (figure 2). Echocardiogram revealed normal left ventricular function without any regional wall motion abnormality. Coronary angiogram (done prior to valve replacement) revealed normal coronaries.
Anteroposterior view of the chest radiograph showing cardiomegaly with perihilar infiltrates.
Echocardiogram showing vegetation (white arrow).
Treatment
The patient was in type 2 respiratory failure at arrival in the emergency department and was hence started on non-invasive ventilation (NIV). However, due to worsening desaturation and poor sensorium, he was soon intubated. Post intubation, his saturations improved. He was started on parenteral antibiotics (levofloxacin and piperacillin–tazobactam), steroids, diuretics and other symptomatic measures. On day 2, the patient developed atrial fibrillation, which reverted with amiodarone infusion.
On day 4, the patient was extubated and again put back on NIV; he was maintaining saturation with 6 L of oxygen.
On day 6, his blood culture (which was sent at the time of admission) came back positive for S. parasanguinis; sensitive to ampicillin, cefotaxime, ceftriaxone and penicillin. This report prompted a reassessment of his clinical status; oral examination revealed that he had poor oral hygiene with dental plaque and caries. On auscultation, a systolic murmur was heard in the mitral area radiating to the axilla. The second echocardiogram was done at this instance. The presence of vegetation lead to modification of his current antibiotics; injection ceftriaxone (2 gm, every 12 hours) was added to the regimen.
Although biomarkers of inflammation/infection had improved, he continued to be in cardiac failure (bilateral basal rales and chest radiograph findings consistent with pulmonary oedema); and a consensus was taken for early valve replacement. After further 2 weeks of triple antibiotic therapy, the patient underwent mitral valve replacement with a mechanical valve. Prior to the surgery, tooth extraction was done as he had dental plaque and caries. Pulmonary function had improved with treatment and the patient was declared fit to undergo valve replacement by the pulmonary physician, although with mild operative risk. Operative findings included a redundant AML with vegetation on its tip. Inflammatory changes were seen on the atrial surface of the posterior mitral leaflet. Postoperative period was uneventful, except for few episodes of fever. Repeat blood cultures were negative. The mitral valve swab culture was also reported as negative. He had completed a full 6-week course of antibiotics. Postoperative echocardiogram was done, which showed a normally functioning prosthetic valve.
Outcome and follow-up
Currently, the patient is convalescing at home and is on oral anticoagulation. He has been counselled regarding the importance of oral hygiene, periodic dental check-up and infective endocarditis prophylaxis.
Discussion
Being a chronic smoker and a known case of COPD, type 2 respiratory failure was considered as an aftermath of acute exacerbation of COPD in this patient. Infections predominantly viral are considered to be the main cause of exacerbation of COPD, followed by other non-infectious causes.2 3 However, this patient had none of these traditional causes of exacerbation described in the literature.
Since the emergence of COVID-19, there has been an increase in the incidence of infective endocarditis in patients recovering from this disease.4 Whether mechanisms involved in the pathogenesis of COVID-19 infection can predispose to infective endocarditis remain a subject of hypothesis. An animal model of infection (infective endocarditis due to Staphylococcus aureus) highlighted the possibility that not only does damaged endothelium predispose to infective endocarditis but a second independent mechanism may involve inflammation of the cardiac valve with expression of surface structures to enhance bacterial adhesion.5 Endotheliitis has been demonstrated in autopsies of patients who died of COVID-19.6 It is plausible that the same mechanisms demonstrated in the animal model may be true for valvular endothelium in COVID-19 patients also.
S. parasanguinis, which is involved in the development of dental plague, is a commensal gram-positive bacterium and a primary coloniser of the human oral cavity.7 It belongs to the viridans group of bacteria. Streptococcal species are a common cause for infective endocarditis; and among the different species of streptococci that cause blood stream infections the highest prevalence of infective endocarditis is with the streptococcal group that includes S. parasanguinis.8
This case is unique in many ways:
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The patient was young, had a history of COVID-19, had native valve infective endocarditis and presented with type 2 respiratory failure and not the usual ‘typical’ manifestations of infective endocarditis (fever, chills, heart murmur, embolic phenomenon).
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He had refractory heart failure requiring early valve replacement.
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His blood culture grew S. parasanguinis, (high prevalence of infective endocarditis among streptococcal blood stream infections), which is seen in the oral cavity.
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Infective endocarditis in the setting of post-COVID-19.
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Men above 45 years of age who have MVP (Mitral Valve Prolapse) are at an increased risk for infective endocarditis.
Learning points
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In a patient with chronic obstructive pulmonary disease presenting with type 2 respiratory failure, one more precipitating cause to be considered is a ‘silent’ infective endocarditis.
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In the setting of post-COVID-19, for any unexplained illnesses infective endocarditis also ought to be ruled out.
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Streptococcus parasanguinis, which was isolated from the blood of this patient, is involved in the development of dental plague and is a primary coloniser of the human oral cavity.
Ethics statements
Patient consent for publication
Footnotes
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Twitter @Abraham Ittyachen. M@abr_itt_m
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Contributors AMI, AP and AS were responsible for drafting of the text, sourcing and editing of clinical images, investigation results, drawing original diagrams and algorithms, and critical revision for important intellectual content. AMI, AP, AS and JV gave final approval of the manuscript.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2023. No commercial re-use. See rights and permissions. Published by BMJ.
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