Streptococcus gallolyticus (S. gallolyticus) has been identified as a pathogen that can cause infective endocarditis. S. gallolyticus infection has also been associated with colorectal cancer. However, to our knowledge, management of both conditions in the same patient has not been reported. Mortality associated with infective endocarditis in patients with existing cancer is higher than in otherwise healthy patients. Also, fewer patients with comorbid infective endocarditis and cancer undergo valvular surgery even if the surgery is clinically indicated.
A 68-year-old man presented with hematochezia, a change in bowel habits and poor appetite for 3 weeks. A blood routine revealed severe anemia (hemoglobin: 6 g/dL).
Shortly after admission, the patient developed fever (38°C) and a blood culture revealed S. gallolyticus infection. No cardiac murmur was noted upon auscultation. An abdominal and pelvic computed tomography (CT) scan revealed a 4 × 3 cm mass with abnormal enhancement in the colon. A biopsy under colonoscopy revealed colon cancer with moderately differentiated adenocarcinoma cells. A whole-body CT scan failed to identify metastatic lesions.
A transthoracic echocardiogram (TTE) showed a 6 × 3 mm echogenic mass that was attached to the right coronary cusp (RCC) of the aortic valve, as well as multiple vegetations on both the aortic and mitral valve leaflets, with moderate aortic regurgitation and mild-to-moderate mitral regurgitation (Figures 1 and 2). Magnetic resonance imaging scans of the brain and spine revealed a cerebral abscess and infective spondylodiscitis (Figure 3). He was started on intravenous benzylpenicillin.
The colon cancer was resected via a laparoscopic Hartmann’s procedure 1 week later. Resected tissue specimens were sent for routine pathologic examination, but not for bacterial culture.
A cardiothoracic surgeon was consulted but advised against valve replacement due to the risk of bleeding while on heparin during on-pump surgery. He was discharged and placed on a 6-week outpatient parenteral anti-biotic therapy program (OPAT) for infective endocarditis. A blood culture at the end of the OPAT failed to grow any bacteria.
Two months later, the patient was rehospitalized for heart failure. Cardiac auscultation revealed an early diastolic murmur. A repeat TEE revealed perforation of the RCC of the aortic valve (Figure 4) with severe aortic regurgitation. Blood culture did not detect any pathogens. A diagnostic coronary angiogram did not show any significant coronary artery stenosis. The patient underwent aortic valve replacement. During the surgery, multiple vegetations were found on the aortic valve but not on the mitral valve. Accordingly, only the aortic valve was replaced. The resected aortic valve tissue was not sent for bacterial culture. A subsequent TTE showed normal mechanical aortic valve function.
Table 1 summarizes a timeline of events that happened during the patient’s two hospitalizations.
Table 1 -
Timeline of events during the patient’s two hospitalizations
|3 weeks before presentation
||Patient developed hematochezia and poor appetite.
|1 day after admission
||Patient developed a fever and was found to be severely anemic.
|3 days after admission
||A CT scan of the abdomen and pelvis (CTAP) showed abnormal colonic enhancement. Blood culture returned, showing S. gallolyticus bacteremia.
|5 days after admission
||Colonoscopy and biopsy revealed colon cancer (adenocarcinoma).
|6 days after admission
||TEE showed multiple vegetations on the aortic and mitral valves. Intravenous anti-biotics was started.
|7 days after admission
||Colon cancer was resected. A cardiothoracic surgeon was consulted, but advised against valve repair/replacement due to the risk of bleeding while on-pump during valve replacement surgery. The patient was stable at this time, and was discharged.
|2 months after initial admission
||Patient was rehospitalized for heart failure. A repeat TEE showed aortic valvular perforation with severe aortic regurgitation.
|2 weeks after second discharge
||Patient underwent aortic valve replacement and recovered uneventfully.
CT: Computed tomography; TEE: Transthoracic echocardiogram.
Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written informed consent is available for review by the editorial office of this journal.
S. gallolyticus was identified as a causative pathogen for infective endocarditis in 1951. Four subtypes were proposed later, and the Streptococcos bovis (S. bovis) biotype I was eventually renamed Streptococcus gallolyticus subspecies gallolyticus (SGSG) SGSG has been associated with colorectal cancer, possibly due to its inflammatory potential and procarcinogenic properties.
S. bovis accounts for up to 57% of all cases of infective endocarditis, with SGSG being the more common subtype[5,6]. Infective endocarditis caused by S. bovis tends to occur more often in elderly men with diabetes mellitus, colonic diseases, or liver cirrhosis, but no traditional predisposing factors for infective endocarditis[5,7,8]. Infective endocarditis caused by SGSG and other bacteria has similar clinical features. Similar to previous reports, the index patient in this report had colon cancer and developed acute fever during hospitalization.
Similar to the characteristics of Streptococcus bovis/Streptococcus equinus complex (SBSEC) infective endocarditis in previous reports[11–13], the lesions in the index patient were relatively large, and involved both the mitral and aortic valves. Notably, upon perforation of the aortic valve (upon the second hospitalization), the patient developed heart failure. Suspected brain abscess and spondylodiscitis are known complications of SBSEC infective endocarditis.
The need for valve replacement and curative resection of colon cancer represent a challenge in this case. Curative resection of the colon cancer was conducted after reasonable control of the endocarditis. Perforation of the aortic valve and heart failure could have been avoided if valve replacement was conducted first, but at the risk of cancer progression.
This case highlights the challenge in prioritizing the management of two comorbid conditions that are both potentially life-threatening. In the current case, curative cancer resection was conducted first, but each case should be analyzed individually by a multidisciplinary team with expertise in all relevant specialties.
YZO provided the case report, images, wrote up the manuscript, and did revisions. WLH contributed to the discussion portion of the manuscript. JJT contributed to proofreading of the manuscript. All three authors contributed to answering questions raised by the reviewers. The manuscript was reviewed and approved by all authors. Each author attests to the integrity of the work.
CONFLICT OF INTEREST STATEMENT
The authors declare that they have no financial conflict of interest with regard to the content of this report.
We would like to thank Changi General Hospital’s team of doctors and National Heart Centre Singapore’s cardiothoracic team for taking care of this patient. We would also like to thank his primary cardiologist Dr Vern Hsern Tan for regularly following up on the patient subsequently.
. Mesa del Castillo-Paya C, Rodriguez-Esteban M, QuijadaFumero A, et al. Infective endocarditis in patients with oncological diseases. Enferm Infecc Microbiol Clin. 2018;36:72–77. doi:10.1016/j.eimc.2016.10.011.
. Gupta A, Madani R, Mukhtar H. Streptococcus bovis endocarditis, a silent sign for colonic tumour. Colorectal Dis. 2010;12:164–171. doi:10.1111/j.1463-1318.2009.01814.x.
. Schlegel L, Grimont F, Ageron E, et al. Reappraisal of the taxonomy of the Streptococcus bovis/Streptococcus equinus complex and related species: description of Streptococcus gallolyticus subsp. gallolyticus subsp. nov., S. gallolyticus subsp. macedonicus subsp. nov. and S. gallolyticus subsp. pasteurianus subsp. nov. Int J Syst Evol Microbiol. 2003;53:631–645. doi:10.1099/ijs.0.02361-0.
. Devriese LA, Vandamme P, Pot B, et al. Differentiation between Streptococcus gallolyticus strains of human clinical and veterinary origins and Streptococcus bovis strains from the intestinal tracts of ruminants. J Clin Microbiol. 1998;36:3520–3523. doi:10.1128/JCM.36.12.3520-3523.1998.
. Abdulamir AS, Hafidh RR, Abu Bakar F. The association of Streptococcus bovis/gallolyticus with colorectal tumors: the nature and the underlying mechanisms of its etiological role. J Exp Clin Cancer Res. 2011;30:11. doi:10.1186/1756-9966-30-11.
. Corredoira J, Alonso MP, Coira A, et al. Characteristics of Streptococcus bovis endocarditis and its differences with Streptococcus viridans endocarditis. Eur J Clin Microbiol Infect Dis. 2008;27:285–291. doi:10.1007/s10096-007-0441-y.
. Boleij A, van Gelder MM, Swinkels DW, et al. Clinical Importance of Streptococcus gallolyticus infection among colorectal cancer patients: systematic review and meta-analysis. Clin Infect Dis. 2011;53:870–878. doi:10.1093/cid/cir609.
. Murdoch DR, Corey GR, Hoen B, et al. Clinical presentation, etiology, and outcome of infective endocarditis in the 21st century: the International Collaboration on Endocarditis-Prospective Cohort Study. Arch Intern Med. 2009;169:463–473. doi:10.1001/archinternmed.2008.603.
. Giannitsioti E, Chirouze C, Bouvet A, et al. Characteristics and regional variations of group D streptococcal endocarditis in France. Clin Microbiol Infect. 2007;13:770–776. doi:10.1111/j.1469-0691.2007.01753.x.
. Hoen B, Chirouze C, Cabell CH, et al. Emergence of endocarditis due to group D streptococci: findings derived from the merged database of the International Collaboration on Endocarditis. Eur J Clin Microbiol Infect Dis. 2005;24:12–16. doi:10.1007/s10096-004-1266-6.
. Moellering RC Jr, Watson BK, Kunz LJ. Endocarditis due to group D streptococci. Comparison of disease caused by streptococcus bovis with that produced by the enterococci. Am J Med. 1974;57:239–250. doi:10.1016/0002-9343(74)90448-3.
. Pergola V, Di Salvo G, Habib G, et al. Comparison of clinical and echocardiographic characteristics of Streptococcus bovis endocarditis with that caused by other pathogens. Am J Cardiol. 2001;88:871–875. doi:10.1016/s0002-9149(01)01914-2.
. Habib G, Lancellotti P, Antunes MJ, et al. 2015 ESC Guidelines for the management of infective endocarditis: the Task Force for the Management of Infective Endocarditis of the European Society of Cardiology (ESC). Endorsed by: European Association for Cardio-Thoracic Surgery (EACTS), the European Association of Nuclear Medicine (EANM). Eur Heart J. 2015;36:3075–3128. doi:10.1093/eurheartj/ehv319.