A Systolic Murmur Late after Infective Endocarditis: Looking for the Guilty.

Aortic location of infective endocarditis is a risk factor for perivalvular extension of infection, even when a native valve is involved. We report the case of a 50-year-old man with a systolic murmur and a history of previous aortic valve infective endocarditis requiring cardiac surgery. A thorough echocardiographic assessment, including three-dimensional transesophageal echocardiography, clearly demonstrated the presence of two distinct postinfective complications, i.e., a fistula of the mitral-aortic intervalvular curtain communicating in systole with the left atrium and an acquired Gerbode-type ventricular septal defect. Our case highlights the pivotal role of echocardiography for a correct and comprehensive diagnostic assessment in the complex scenarios frequently encountered after infective endocarditis. Copyright:

INTRODUCTION

Prosthetic valve endocarditis with perivalvular extension is known to be associated with a poor prognosis.[12] Although surgical repair is frequently indicated, in some complex cases, where a correct management strategy remains controversial, bidimensional and three-dimensional transesophageal echocardiography may play a crucial role, by providing essential anatomic and functional information.

CASE REPORT

A 50-year-old man with mechanical aortic valve prosthesis was referred to our attention with moderate dyspnea during efforts (New York Heart Association Class II).

He had a history of alcoholic cirrhosis. In 1990, he had suffered an episode of infective endocarditis requiring surgical aortic valve replacement with a mechanical prosthesis and tricuspid valve annuloplasty. The follow-up was uneventful in the absence of symptoms and any features suggestive of persistent and/or relapsing infection. The patient was currently on therapy with beta-blockers, angiotensin-converting enzyme inhibitors, and warfarin, and no clinical signs of decompensation were evident. Prosthetic valve clicks were clearly audible and a Grade 3 systolic murmur was appreciable along the left lower sternal edge.

No clinical and/or laboratory features of hemolysis were present.

Transthoracic echocardiography showed a normally functioning prosthetic aortic valve with a mild intraprosthetic washout and absence of paravalvular leaks and/or vegetations [Video 1]. The left ventricle (LV) was slightly dilated, with preserved ejection fraction. However, two anomalous systolic jets arising near the prosthetic aortic valve and directed toward both atria were displayed [Video 2].

A transesophageal echocardiogram was then performed, to elucidate the exact mechanism underlying these anomalous jets.

A first jet was shown to result from an outpouching of the mitral-aortic intervalvular curtain communicating in systole with the LA cavity [Video 3 and Figure 1].

Figure 1

(a) Three-dimensional echo reconstruction of the mitral-aortic fibrosa. The intervalvular curtain outpouching is indicated by a red arrow. (b) Three-dimensional color Doppler reconstruction of the communication between left ventricle and left atrium through the mitral-aortic curtain

The second jet was demonstrated being a moderate Gerbode-type ventricular septal defect with a direct systolic communication between the LV and the right atrium [Video 4].

Serial blood cultures and an 18F-fluorodeoxyglucose positron emission tomography/computed tomography scan were also performed, all being negative for active infection.

Therefore, since our patient was not keen on a redo surgery and exhibited a good clinical status, stable during a long-term follow-up, along with echocardiographic evidence of preserved biventricular function and absence of significant volume overload, we adopted a conservative approach with watchful observation.

DISCUSSION

Uncontrolled infection represents one of the most feared complications of infective endocarditis, often associated with a poor prognosis, and requiring early surgery.[12] The aortic location of endocarditis is a risk factor for perivalvular extension of infection, which occurs most frequently in the mitral-aortic fibrosa.[34] However, the mitral-aortic fibrosa can be compromised also during aortic or mitral valve surgery, especially in the presence of extensive calcification.[3] Similarly, the Gerbode defect, when acquired, can occur after acute infective endocarditis or can complicate surgical or percutaneous cardiac intervention involving the membranous atrioventricular septum. In case of endocarditis, the LV-right atrial defect can be due to reopening of a congenital defect, widening of a small shunt or destructive perforation of the septum.[56]

The management of such a scenario remains a challenging issue.

The coexistence of advanced liver disease, which has been demonstrated being a predictor of nonsurgical management in the real-world setting, increases the risk of a redo surgery, also at a relatively young age, as in our case.[7] Therefore, on the basis of patient's preference, in presence of a long-lasting stable good clinical status and the documented absence of active infection, we deemed surgery not urgent, prompting it in case of changes of the clinical and instrumental features during a strict follow-up.

On the other hand, a percutaneous closure might be a viable alternative, but it has to deal with an increased risk of either new infection or interference with the motion of the prosthetic leaflets.

Accordingly, a conservative strategy and watchful observation, along with serial echocardiographic assessment, were deemed the most reasonable option in terms of risk-to-benefit analysis.

CONCLUSIONS

Coexisting multiple routes of intracardiac communication can complicate infective endocarditis, especially when the aortic valve is involved.

Three-dimensional transesophageal echocardiography confirms its pivotal role for a correct and comprehensive diagnostic assessment of such unusual complications.

The optimal management strategy in cases like ours remains challenging and should be primarily based on a multidisciplinary weighted evaluation of the risk-to-benefit ratio of a surgical approach.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.