Infective endocarditis (IE) without murmurs (silent IE) is an entity fraught with the risk of missed diagnosis. This hazard is attributable to a suboptimal index of suspicion for IE, and, hence, suboptimal workup for IE, when a murmur is absent. This state of affairs was exemplified by anecdotal reports of 15 adult patients (11 male) of mean age 48 years who were characterised by the association of silent IE and mucocutaneous stigmata of IE (table 1),1–15 and in whom echocardiography was initiated after a delay of one day to seven months (median seven days) following documentation of mucocutaneous stigmata. None had ‘same day’ echocardiography. In addition to mucocutaneous stigmata, nine of the 15 patients also had risk factors for IE, namely, dental caries,9,10,12,15 ear piercing,11 post-operative wound infection,3 intravenous drug use,13 and cirrhosis of the liver.2,6 Three patients had an afebrile presentation.2,12,13 Echocardiography disclosed vegetations in 13 patients.1–4,6–8,10–15 Eight patients (including four with risk factors for endocarditis) subsequently developed new murmurs.1,2,5,6,9,12,14,15 In five of those cases echocardiography was undertaken after detection of the murmur.1,2,9,14,15
Table 1. Clinical features and complications
| First author | Symptoms / complications | Pur | Jn | Spl | SCH | Os | Valve | Culprit pathogen |
|---|---|---|---|---|---|---|---|---|
| Cecarelli1 | Meningitis, SMA, SE | Y | N | N | N | N | Mitral | Staph. aureus |
| Deonarine2 | Cirrhosis, CHF, spondylitis | Y | N | N | N | N | Quadrivalve | Strep. mutans |
| El Chami3 | CHF, respiratory failure | Y | N | N | N | N | Aortic | Enterococcus faecalis |
| Yokota4 | Mesenteric abscess | Y | N | N | N | N | Mitral | MSSA |
| Miridjanian5 | Fever, myalgia, headache | Y | N | Y | Y | N | Aortic | Moraxella kingae |
| Mahmoud6 | Cirrhosis, CHF, ICE | Y | N | N | N | N | Mitral | Pasteurella multocida |
| Tiliakes7 | Polyarthralgia, ANCA+ve, splenomegaly | Y | N | N | N | N | Aortic | Strep. viridans |
| Messiaen8 | CHF, Gln, ANCA+ve | Y | N | N | N | N | Aortic | Few bacterial colonies |
| Chukwurah9 | Gln, ICE | Y | N | Y | N | N | Aortic | Lactobacillus, Acidophilus |
| Branch10 | ICE | N | Y | N | Y | Y | Mitral | Pasteurella multocida |
| Nah11 | ICE, meningitis, CHF, SE, RE | N | Y | Y | Y | N | Mitral | MRSA |
| Nichols12 | ICE | N | Y | N | N | Y | Mitral | Strep. viridans |
| Yeung13 | ICE, CHF, SMA, SE | N | N | Y | Y | N | Aortic | Serratin marcescens |
| Ching14 | ICE | N | N | N | N | Y | Aortic | MSSA |
| Inoue15 | CHF, spondylitis, septic arthritis | N | N | N | N | Y | Aortic | MSSA |
| Key: ANCA+ve = positive for anti-neutrophilic cytoplasmic antibodies; CHF = congestive heart failure; Gln = glomerulonephritis; ICE = intracranial embolism; Jn = Janeway lesions; MRSA = methicillin-resistant Staphylococcus aureus; MSSA = methicillin-sensitive Staphylococcus aureus; N = No; Os = Ostler’s nodules; Pur = purpura; RE = renal embolism; SCH = subconjunctival haemorrhages; SE = splenic embolism; SMA = skeletal muscle abscess; Spl = splinter haemorrhages; Y = Yes | ||||||||
Complications comprised intracranial embolism (ICE, seven cases), congestive heart failure (seven cases), meningitis (two cases), spondylitis (two cases), skeletal muscle abscess (two cases), septic arthritis (one case), mesenteric abscess (one case), splenic embolism (two cases), splenic embolism in association with renal embolism (one case), acute glomerulonephritis (two cases).
Treatment
Valve replacement was undertaken in seven cases,3,8–11,13,15 including three with torrential left ventricular failure attributable to valve cusp perforation.3,8,11 One patient had mitral valvuloplasty.12 Seven patients (including two deaths, both with congestive heart failure and cirrhosis),2,6 were managed conservatively.
Comment
Among 54 IE patients with mucocutaneous stigmata, Servy et al. identified 18 with no murmurs. Intracranial embolism and extracranial embolism, respectively, were prevalent in 32.8% and 51.7% of patients. Immunological phenomena were significantly more common in IE patients with mucocutaneous stigmata than in counterparts without those stigmata.16 The present review takes the characterisation of silent IE further by documenting the cognitive bias that hinders timely investigation of this syndrome.
Conflicts of interest
None declared.
Funding
None.
Acknowledgement
I am grateful to Mrs A Russell for secretarial assistance.
References
1. Ceccarelli G, d’Ettorre G, Vullo V. Purulent meningitis as an unusual presentation of Staphylococcus aureus endocarditis: a case report and literature review. Case Rep Med 2011;2011:735265. https://doi.org/10.1155/2011/735265
2. Deonarine B, Lazar J, Gill MV, Cunha BA. Quadri-valvular endocarditis caused by Streptococcus mutans. Clin Microbiol Infect 1997;3:139–41. https://doi.org/10.1111/j.1469-0691.1997.tb00267.x
3. El Chami S, Jibbe A, Shabouri S. Bacterial endocarditis presenting as leukocytoclastic vasculitis. Cureus 2017;9:e1464. https://doi.org/10.7759/cureus.1464
4. Yokota K, Sakamoto A, Takatsu F, Hashida S. A case of infective endocarditis mimicking a large mesenteric abscess. J Infect Chemother 2022;28:995–7. https://doi.org/10.1016/j.jiac.2022.03.005
5. Miridjanian A, Berrett D. Infective endocarditis caused by Moraxella kingae. West J Med 1978;129:344–6. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1238366/
6. Mahmoud M, Kortbi K, Abdalla M, Habib S. Rare but fatal Pasteurella multocida infective endocarditis: a case report and literature review. Cureus 2022;14:e22950. https://doi.org/10.7759/cureus.22950
7. Tiliakos AM, Tiliakos NA. Dual ANCA positivity in subacute bacterial endocarditis. J Clin Rheumatol 2008;14:38–40. https://doi.org/10.1097/RHU.0b013e318164187a
8. Messiaen T, Lefebvre C, Zech F, Cosyns JP, Jadoul M. ANCA-positive rapidly progressive glomerulonephritis: there may be more to the diagnosis than you think. Nephrol Dial Transplant 1997;12:839–41. https://doi.org/10.1093/ndt/12.4.839
9. Chukwurah VO, Takang C, Uche C, Thomas DB, Masry W, Toka HR. Lactobacillus acidophilus endocarditis complicated by pauci-immune necrotizing glomerulonephritis. Case Rep Med 2020;2020:1607141. https://doi.org/10.1155/2020/1607141
10. Branch J, Kakutani T, Kuroda S, Shiba Y, Kitagawa I. Pasteurella multocida infective endocarditis: a possible link with primary upper respiratory tract infection. Intern Med 2015;54:3225–31. https://doi.org/10.2169/internalmedicine.54.4973
11. Nah S-Y, Chung M-H, Park JE, Durey A, Kim M, Lee J-S. Infective endocarditis caused by methicillin-resistant Staphylococcus aureus in a young woman after ear piercing: a case report. J Med Case Rep 2011;5:336. https://doi.org/10.1186/1752-1947-5-336
12. Nichols L, Hernandes M, Henderson JH. Infective endocarditis masked by narrow focus thinking, inadequate physical examination and analgesic medication. Cureus 2019;11;e5645. https://doi.org/10.7759/cureus.5645
13. Yeung H-M, Chavarria B, Shahsavari D. A complicated case of Serratia marcescens infective endocarditis in the era of the current opioid epidemic. Case Rep Infect Dis 2018;2018:5903589. https://doi.org/10.1155/2018/5903589
14. Ching S, Yue CS. A man with fever and rash. Eur J Intern Med 2018;50:e1–e2. https://doi.org/10.1016/j.ejim.2017.07.005
15. Inoue K, Kozawa J, Funahashi T et al. Right sided acute suppurative thyroiditis caused by infectious endocarditis. Intern Med 2011;50:2893–7. https://doi.org/10.2169/internalmedicine.50.5790
16. Servy A, Valeyrie-Allanore L, Alla F et al. Prognostic value of skin manifestations of infective endocarditis. JAMA Dermatol 2014;150:494–500. https://doi.org/10.1001/jamadermatol.2013.8727
