Infective Endocarditis Complicated with Anterior Mitral Leaflet Abscess: A Case Report.

Infective endocarditis (IE) is defined as infection of endocardial surface of the heart. It may include one or more heart valves, the mural endocardium or a septal defect. Its intracardiac effect includes severe valvular insufficiency which may lead to intractable congestive heart failure and myocardial abscess. Infective endocarditis especially complicated by an abscess is associated with high mortality, despite the medical and surgical therapeutic options available. Surgical intervention is indicated in cases of heart failure or uncontrolled infection and sometimes for the prevention of embolic phenomena. We report a case of 42 yrs/M with RVHD admitted in Dr D.Y.Patil hospital, Kolhapur. He had high grade, continuous fever, vomiting, cough with expectoration since 15 days prior to admission. He had prior embolic stroke 2 months back from which he recovered completely. The diagnosis of Infective endocarditis was confirmed clinically & echocardiographically by Duke's criteria. His ECHO showed severe MR, Moderate MS and large vegetations on AML oscillating through mitral orifice along with subvalval (mitral) abscess. Due to severe haematemesis following Mallory weiss tear surgical intervention was not possible. Patient succumbed as a result of refractory pulmonary oedema.

INTRODUCTION

Infective endocarditis is a microbial infection of native (intact) or degenerated cardiac valves, the endothelium surrounding congenital or acquired cardiac defect and the endothelium of vascular malformations.[1] It is classified into 2 types: Acute and subacute. Acute endocarditis is a febrile illness that rapidly damages cardiac structures whereas subacute endocarditis follows an indolent course and slowly causes structural cardiac damage.[1]

In developed countries, the incidence of endocarditis ranges from 2.6 to 7 cases per 100,000 populations per year, more in males than females. Predisposing conditions for infective endocarditis include congenital heart disease, rheumatic heart disease, IV drug use, degenerative valve disease and intracardiac devices.[12]

Clinical manifestations of infective endocarditis include high grade fever, chills, sweating, anorexia, malaise, heart murmur, new or worsened regurgitant murmur, arterial emboli, splenomegaly with peripheral manifestations such as oslers nodes, subungual hemorrhages, Janaway lesions, Roths spot etc.

Diagnosis is made with help of Duke's criteria, which is based on blood culture findings, echocardiography and routine biochemical tests [Video 1–6].

Infective endocarditis leads to complications such as congestive cardiac failure, peri-valvular abscesses, which in turn may cause intracardiac fistulae, cerebrovascular emboli presenting as stroke, aseptic or purulent meningitis, intracranial hemorrhage due to hemorragic infarcts or ruptured mycotic aneurysm and seizures.[1]

Although there are many complications of disease few cases reported are complicated by an abscess of cardiac valve leaflet as per our knowledge.[23] After thorough literature search we were unable to find prevalence of cardiac valve abscess.

Herein, we report a case of infective endocarditis complicated by an abscess of the anterior mitral valve leaflet.

CASE REPORT

A 45-year-male cook, a resident of Shahunagar, Kolhapur, was admitted on 1st Nov 2013. He had complaints of high grade, continuous fever with chills, multiple episodes of vomiting, cough with whitish colour expectoration since 15 days. Patient was having RVHD, diagnosed recently. He had history of left sided hemiparesis associated with 2 episodes of seizures 2 month back (MRI brain with MRA done showed acute infarct in middle frontal gyrus). He recovered completely. Since then he was on antiplatelet and antiepileptic medications. No family history of congenital or rheumatic heart disease. History of IV drug abuse was negative.

On clinical examination, patient was febrile (Temp-103°F). He had Pallor, tachypnea bilateral mild pedal edema. His cardiovascular examination revealed pansystolic murmur at mitral area conducted to axilla. On respiratory system examination, he had bibasal crepitations. On examination of the abdomen, mild splenomegaly was present.

His complete blood count examination showed moderate anemia (Hb 8.1 gm%), thrombocytopenia (80, 000/cmm), which worsened later to (47,000/cmm,) raised ESR (52 at the end of 1 hr). Tests for Dengue fever, Malaria, and Brucella were negative. Montoux test also was negative.

Electrocadiogram (ECG) showed occasional VPC's. Mild cardiomegaly was noted on chest radiograph. 2D ECHO on 4/11/2013 showed good left ventricular function, Grade II mitral regurgitation, moderate MS, large vegetations over anterior mitral leaflelet measuring 19 × 6 mm [Figure 1].

Figure 1

2 D Echo parasternal long axis showing vegetations at AML and PML

The diagnosis of acute infective endocarditis was confirmed by applying Duke's criteria. However, blood cultures were negative, possibly due to use of antibiotics. He was put on antibiotics (injectable Ceftriaxone, Amikacin later on shifted to injectable piperacillin tazobactum, Gentamycin and Meropenam). Inspite of that fever persisted, so we repeated 2D Echo on 21st Nov 2013. This time it showed severe MR (Grade IV), moderate MS, vegetations at anterior mitral leaflet-oscillating through mitral orifice along with subvalval anterior mitral leaflet abscess [Figure 2].

Figure 2

2 D Echo AP4CH showing AML abscess and vegetations at AML and PML

In view of development of an abscess on anterior mitral leaflet, higher antibiotics were added and emergency surgery was planned. Over next 2 days fever subsided. But he had intense hematemesis and epistaxis on 25th November. Upper GI endoscopy was done, which revealed Mallory weiss tear. In view of bleeding from many sites due to thrombocytopenia, the cardiovascular surgery had to be postponed. Patient was treated symptomatically with proton-pump inhibitors, Sucralfate and packed cell volume transfusion. He remained afebrile for 4 days although continued to have high grade, continuous fever later. Antibiotics were changed and antifungal drugs (Fluconazole) were added. Patient suddenly landed up in refractory pulmonary edema and unfortunately succumbed in hospital on 41st day of hospitalization, i.e. on 11th December 2013.

DISCUSSION

There are many complications of infective endocarditis, but an abscess of the cardiac valves is rare. Aortic involvement in the setting of degenerative disease is more common than isolated mitral valve involvement in RVHD. The diagnosis of infective endocarditis is based on Duke's criteria.[1] In our case, 1 major criterion and 5 minor criteria were fulfilled that are sufficient for the diagnosis of infective endocarditis. In spite of using higher broad spectrum antibiotics, patient did not respond to the treatment probably because of the abscess on the vessel-free anterior mitral valve leaflet.

Bacterial endocarditis usually occurs on valves previously damaged by other disease processes (for example rheumatic heart disease or mitral valve prolapse). Sometimes Congenital heart disease may present as a risk factor for cardiac sepsis.

Bacterial endocarditis that is predisposed by degenerative lesions has high incidence with increasing age.[4] Valvular abnormalities induce stenotic or regurgitant lesions with high velocity jets. These traumatize endothelium and the ensuing endocardial erosion is locations of possible infections. Patients with mitral insufficiency typically develop vegetations on the atrial surface of the mitral leaflets.

Annular abscess are a well-known complication of aortic valve endocarditis. Calcification of valves is a risk factor for abscess formation in relation to poor diffusion of antibiotics.[4]

Most of the cases of infective endocarditis are treated surgically due to serious complications. This option should be considered in the active phase of disease to prevent progression of heart failure, irreversible structural damage and systemic embolism.

Current indications for surgical treatment are:

Refractory heart failure directly related to valve dysfunction.

Uncontrolled infection and prevention of embolic phenomena.

Large mobile vegetations greater than 10 mm diameter.

Persistent unexplained fever in culture-negative native valve endocarditis.[12]

CONCLUSION

We conclude that prognosis of infective endocarditis complicated with a mitral valve leaflet abscess is poor and early surgical treatment should be advocated to improve patient survival.