Infective Endocarditis of Mitral valve with severe mitral regurgitation (MR) secondary to Infective Endarteritis of intracoronary stent.

1. Infective Endocarditis of Mitral valve with severe mitral regurgitation (MR) secondary to Infecti ve
Endarteritis of intracoronary stent.
Dr C K Ponde, DM, DNB, MD.
Dr Sumedh Ramteke, MD, DNB cardiology resident,
ABSTRACT:
Percutaneous transluminal coronary angioplasty (PTCA) is a well established technique for the treatment of
coronary stenosis, however infection can occur around the intravascular prosthesis leading to a number of
complications. Infective endarteritis of intracoronary stent is a rare occurrence with only around 80 cases having
reported so far since the introduction of coronary stents in 19871. We present a rare case of a 60 year old man who
had undergone percutaneous coronary intervention procedure during which two overlapping stents were implanted
in the mid portion of the right coronary artery (RCA). 45 days after the procedure, patient started having fever and
presented to us 3 months from the time of intervention after having received unsuccessful antibiotic therapy in
outside hospital. He was found to have Mitral Valve Endocarditis due to infection of intracoronary stent.
CASE REPORT:
Mr. D B, 60 year old male, a known hypertensive, with history of PTCA 3 months prior, presented to hospital with
complaints of fever associated with chills, anorexia and vomiting for 1 & 1/2 months. The patient had similar
episodes of fever for which he was admitted to an outside hospital several times and received antibiotics, however
fever with chills continued. He gave history of weight loss of around 10-12 kg during the previous 2 months. The
patient was admitted in an ICU elsewhere where his blood culture showed growth of pseudomonas aeruginosa
which was resistant to all antibiotics except Colistin and hence was started on Colistin. Patient gave history of
having undergone PTCA to LAD (3 × 18 excel stent) and LCx (2.5 × 18 excel stent) in 2012. In 2014, he again
underwent PTCA wherein 2 stents were put in RCA (proximal 3×36 sirolimus and distal 2.75 × 36 sirolimus).
At presentation to our hospital, he was febrile with temperature of 1030 F and was tachycardic as
well as tachypnoeic. Cardiovascualar system examination revealed pansystolic murmur (PSM) of grade IV/VI
intensity with S3 gallop heard in apical area. Rest of the system examinations were unremarkable.
We evaluated this patient in our hospital with relevant investigations.
Laboratory parameters :
1. White Blood cell count - 20,856/mm3 .
2. ESR of 85 mm/hr.
3. ECG revealed old anterior wall myocardial infarction (AWMI) changes.
4.Transthoracic Echocardiography (TTE) - showed presence of vegetation on AML measuring 1.1 cm x 0.6 cm with
severe MR and LVEF (Left ventricular ejection fraction) of 35 %
5. TransesophagealEchocardiography (TEE) – confirmed the presence of vegetation on AML and severe MR.
6. CT Angiography-revealed thrombosis of both the stents in the RCA due to coronary endarteritis which finally
resulted in the entire mid RCA converting into an abscess cavity and the sheer forces leading to fracture of stent
into 3 pieces.
7. Coronary Angiography-showed patent stents in LAD and LCx artery and both the RCA stents were blocked and
fractured.
8. Blood cultures- showed growth of pseudomonas aeruginosa.
9. Tissue culture (operative specimen) - showed growth of atypical mycobacteria .
Blood cultures were sent. While awaiting reports, we continued him on Colistin. Reference was given
to Infectious Disease specialist and was advised to start Imipenem along with Colistin. Cardiac Surgeon was invited
and the heart team approach involving Cardiologist, Infectious Disease Specialist and Cardiac Surgeon, all of us
decided that this patient will require urgent surgery.
Surgical Details: Underwent Mitral Valve Replacement (MVR) surgery (bioprosthetic 25 mm Paramount valve)
with entire RCA cavity aspirated, debrided and proximal to distal RCA ligation with a graft to PDA was done.
Prior to surgery, he was receiving Colistin and Imipenem. Further blood culture report showed
sensitivity to Ceftazidime and Ciprofloxacin. Hence, Imipenem was withdrawn and he was given Ceftazidime and
Ciprofloxacin along with Colistin. Tissue culture (operative specimen) showed growth of atypical mycobacteria for

2. which he was started antitubercular treatment and advised to continue for 9 months. On post operative day 25, he
was discharged to home as he was haemodynamically stable. On follow up, transthoracic echocardiography was
done which revealed bioprosthetic mitral valve in situ and functioning well with no valvular or paravalvular leak
without any evidence of vegetation, pericardial effusion or clot. During follow up at 1 year post the surgery and after
completing antitubercular treatment, patient was doing well.
DISCUSSION:
Our literature search yielded around 80 patients with coronary stent infections. The definitive diagnosis of stent
infection was based on the presence of an abscess or an inflammatory mass or an aneurysm. Diagnosis work up
should include information regarding the time of onset of symptoms in relation to stent placement, presenting
symptoms, duration of symptoms, organisms isolated on culture, echocardiography and imaging findings. Early
onset infections were defined as those occurring less than 10 days from stent placement and late onset infectio ns as
those occurring 10 days or longer from stent placement. 2 The present case report describes the late development of
an infection of a coronary Drug Eluting Stent (DES). This patient presented 3 months post the stent implant with 1
& ½ month history. The patient was evaluated for bacteremia refractory to antibiotics with blood and tissue culture,
Transthoracic and Transesophageal Echocardiography, CT coronary angiography which gave us the diagnosis. The
patient was managed with surgery and survived after a prolonged, complicated hospital course. We used the criteria
proposed by Dieter to determine the diagnosis of coronary stent infection. For a possible diagnosis, 3 of the
following criteria must be fulfilled : (1) Placement of a coronary stent within the previous 4 weeks, (2) Multiple
repeat procedures performed through the same arterial sheath, (3) presence of bacteremia, (4) Significant fever, (5)
Leucocytosis with no other cause, (6) Acute coronary syndrome, (7) Positive cardiac imaging 3. Infections involving
inserted stents are quite rare, nevertheless, the outcome is highly fatal. Therefore we still need to pay close attention
to its possibility to decrease the fatality. The exact mechanism of stent infection remains unclear, could it be a result
of infection within 2 weeks of stent placement or of a haematogenous spread from another source of bacteremia.
With the use of Drug Eluting Stent (DES) the reports of stent infection has increased because of the inhibition of the
neointimal growth leading to the metallic stent remaining uncovered intraluminally, therefore forming a nidus for
the adhesion of bacteria especially in late stent infections 4. Therefore, it is very important to have a high degree of
clinical suspicion for this potential complication. Other risks factors associated with stent infection include imperfect
sterility of procedure, prolonged use of indwelling catheter and extensive changing of wires. Stent infection
unfortunately has become a common phenomenon in our country due to the reuse of PTCA balloon catheters poorly
sterilised in cidex solution.
CONCLUSION:
In any patient who presents with unexplained fever within 8 weeks of intracoronary stent implantation , should be
suspected of having infection of an intracoronary stent. Multiple sets of blood culture and CT coronary angiography
to see the status of the stent and spread of infection in peri-stent area would immensely help in diagnosis. Early
surgical intervention should be carried out as success rate with conservative antibiotic therapy are poor. Stent
removal should be opted for during the time of surgery, following which adequate antibiotic therapy should be given
post the surgery, for at least a period of 4 weeks or longer if the stent is not removed during surgery. If this is not
possible, then at least exclusion of the infected stented segment of artery from the circulation is a must for
permanent cure. It must be remembered that tissue culture might show an additional organism not captured in blood
cultures which will require appropriate therapy for at least 4 weeks.

3. FIGURE 1 A and B : TTE and TEE showing AML vegetation and severe MR.
FIGURE 2 A and B : CT angiography showing RCA stents fractured and blocked.

4. FIGURE 4 A and B : angiography showing RCA stents fractured and blocked.
FIGURE 3 A and B : Intra operative images.

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