Infectious endocarditis with systemic septic embolization as a rare complication of cardiac catheterization

Abstract

A case of infectious endocarditis with septic embolization as a rare but potentially fatal complication of cardiac catheterization is described, followed by a detailed review of the literature. Obesity, diabetes, many skin punctures, previous bypass surgery and abnormal valves are predisposing factors for bacteremia following cardiac catheterization.

CASE PRESENTATION

A 69-year-old woman with a history of coronary artery disease, coronary artery bypass graft surgery (six months previously), type 2 diabetes mellitus, hypertension and hypercholesterolemia presented to a local emergency department with a prolonged episode of chest pressure, dyspnea and diaphoresis. A review of the rest of her symptoms was unrevealing. Her vital signs were stable. Her temperature was 36.0°C, and the remainder of her examination was normal except for obesity. Cardiac auscultation did not reveal any murmurs. An electrocardiogram demonstrated inverted T waves in leads V2 through V6, and serial troponin T levels were mildly elevated at 0.65 μg/L. Her white blood cell count was normal (5.3×10⁹/L) with a normal differential cell count. The following day, the patient underwent cardiac catheterization by percutaneous puncture of the right femoral artery using a modified Seldinger approach. Left ventriculography and aortography were performed. The aortic valve was noted to be normal. Coronary angiography revealed a severe ostial lesion of the left main coronary artery and total occlusion of the left internal mammary graft to the left anterior descending artery. Hemostasis was achieved by applying direct pressure to the right femoral artery. No closure device was used. The duration of cardiac catheterization was documented to be approximately 36 min. The patient was referred to a specialized cardiac centre for percutaneous coronary intervention of the left main ostial lesion. Before this procedure, on day 6 after cardiac catheterization, she complained of severe headache. The patient had a temperature of 38.5°C and was noted to have neck stiffness. Her white blood cell count was elevated at 19.1×10⁹/L. Coronary intervention was postponed and she was urgently transferred to the University Medical Centre (Arizona, USA) for management of suspected meningitis. The patient showed no evidence of any other infections before or after her cardiac catheterization.

On neurological examination, she was alert and oriented, with intact cranial nerves. Her strength in the left upper extremity was grade 3/5 and grade 4/5 in the right upper extremity in all muscle groups. Her strength in the lower extremities was grade 4/5 bilaterally. Hyperreflexia was demonstrated in both upper and lower extremities. A grade 2/6 systolic murmur was recognized in the aortic area.

A magnetic resonance imaging scan of the head and neck revealed small subacute embolic infarcts involving the left motor cortex. Magnetic resonance imaging of the neck revealed an epidural fluid collection at the C3 through C6 levels, consistent with epidural abscess (Figure 1). A transthoracic echo-cardiogram demonstrated mobile vegetation on the aortic valve (Figure 2). Subsequently, four blood cultures confirmed the presence of methicillin-sensitive Staphylococcus aureus bacteremia. The patient was treated with the appropriate antibiotic therapy but developed acute respiratory distress followed by an asystolic cardiac arrest that required intubation, and 1 min of cardiopulmonary resuscitation, on day 8 following her cardiac catheterization.

Figure 1).

Magnetic resonance imaging scan of the neck. White arrows indicate an epidural abscess

Figure 2).

Two-dimensional transthoracic echocardiogram. Parasternal short-axis view showing mobile vegetation on the aortic valve (arrow) that can be seen during systole (left)

Subsequently, the patient was found to be quadriplegic. Her spinal abscess was treated with medical therapy based on the recommendations of the consulting neurosurgeon. The patient’s hospital course was complicated with acute renal failure, requiring dialysis and thrombocytopenia, both of which resolved. She was treated with long-term intravenous antibiotics. She was initially treated with vancomycin and ceftriaxone. However, when her cultures were positive for methicillin-resistant S aureus, she was put on cefazolin treatment for eight weeks. Following a two-month period in the medical intensive care unit, the patient was discharged to a rehabilitation facility in stable condition on a chronic ventilator and with percutaneous gastrostomy feeding.

DISCUSSION

Infections complicating cardiac catheterization

Bacteremia following cardiac catheterization is rare. In a prospective study (1) that evaluated 960 patients undergoing cardiac catheterization, only 0.4% of patients had positive blood cultures that were significantly associated with cardiac catheterizations and percutaneous coronary interventions. The risk factors for bacteremia following catheterization include obesity, duration of procedure, number of balloons used and the number of skin punctures performed.

Bacteremia occurring secondary to cardiac catheterization rarely leads to systemic or localized infection. Such infections reported as complications of percutaneous coronary intervention and coronary angiography include sepsis (2), endocarditis (2–8), suppurative pancarditis (9), stent infection (6,10,11) septic arthritis (12–14), epidural abscess (15), necrotizing fasciitis (16) and groin wound infection (17,18). There are no published reports of native valve endocarditis leading to cerebral embolization, epidural abscess and paraplegia following cardiac catheterization. It is important to mention that we do not have clear evidence that the staphylococcal bacteremia occurred during her cardiac catheterization. It is also possible that the catheterization caused only endocardial damage and had predisposed the patient to infectious endocarditis; subsequently, the bacteremia occurred two days later from other sources such as the nasopharyngeal cavity.

A literature review on endocarditis following cardiac catheterization revealed eight previous cases, which are listed in Table 1. Based on these data, four patients with previous valvular disease had infective endocarditis following cardiac catheterization. Three patients had previously undergone coronary artery bypass graft surgery, similar to our case. Infected stents were found in three patients. The majority of patients developed symptoms and signs of endocarditis between one and seven days after the procedure.

TABLE 1.

Endocarditis following cardiac catheterization

Author (reference), year	Demograpahic details and risk factors	Procedure	Time to endocarditis*	Bacteria isolated	Valve involved	Complications
Index case, 2007	69-year-old woman. History: CABG, obesity, diabetes mellitus	Cardiac catheterization	6 days	Staphylococcus aureus	Aortic	Cerebral infarctions, epidural abscess, quadriplegia, recovery with antibiotics
Palmer and Ramsdale (7), 2005	61-year-old man status post. History: CABG, mild MR	Cardiac catheterization and stenting x2	1 day	Coagulase-negative staphylococcus	Mitral	Hemorrhagic brain infarct due to septic embolus. Recovery with antibiotics
Ross et al (4), 2001	63-year-old woman. History: Obesity, CABG, on low-dose steroids	Angioplasty and stenting	Following month	Corynebacterium jeikeium	Aortic	Multiorgan failure and death
Leroy et al (6), 1996	49-year-old man. History: CAD	Palmaz-Schatz stent and control angiography one day later	7 days	Pseudomonas aeruginosa	Mitral	LAD aneurysm, anterior mitral valve chordae rupture. Cardiac arrest and death following CT surgery
McCready et al (2), 1991	56-year-old woman	Catheterization and PTCA	1 day	S aureus	Aortic	Aortic valve insufficiency and death
	70-year-old woman	Catheterization and PTCA	1 day	S aureus	Aortic	Septic emboli. Recovery with antibiotics
Perez (3), 1986	57-year-old man. History: rheumatic valve disease	Cardiac catheterization	3 days	Moraxella-like M-6 bacteria	Aortic	Recovery following atrioventricular valve replacement
Rubin et al (5), 1978	63-year-old man. History: CAD and rheumatic valve disease	Cardiac catheterization	5 days	Micrococcus mucilaginosus incertae sedis	Mitral	Recovery with antibiotics
Winchell (8), 1953	44-year-old woman. Rheumatic mitral valve	Cardiac catheterization	11 days	Alpha-hemolytic streptococcus	Mitral	Recovery with antibiotics

^*Duration after procedure for endocarditis to appear. CABG Coronary artery bypass graft; CAD Coronary artery disease; CT Cardiothoracic; LAD Left anterior descending; PTCA Percutaneous transluminal coronary angioplasty

A wide variety of bacteria caused endocarditis in these case series. The most common causative organism of bacteremia following cardiac catheterization is S aureus (19), similar to our patient. Furthermore, our patient had diabetes – a risk factor for endocarditis in the general population (20). Obesity is another risk factor for bacteremia during cardiac catheterization, which was also present in our patient (1). Obese patients have been noted to have chronic S aureus colonization of the skin in the groin region (21). This can explain the increased susceptibility of these patients to staphylococcal bacteremia during femoral puncture.

In most reported cases, the aortic valve was predominantly affected, except in patients with previous mitral valve disease. Three of the eight reported cases had a fatal outcome, suggesting that a poor prognosis is associated with infectious endocarditis in the setting of cardiac catheterization.

Based on the guidelines for infectious endocarditis, antibiotic prophylaxis is not recommended before performing cardiac catheterization in high-risk patients. Cardiac catheterization is not significantly associated with bacteremia. Despite our case of infectious endocarditis, possibly occurring during the cardiac catheterization procedure, we do not support routine use of antibiotic prophylaxis before cardiac catheterization in high-risk patients. To date, available clinical data do not support prophylactic antibiotic treatment.

A further literature review revealed that iatrogenic causes of infectious endocarditis occur in 28.4% of all endocarditis cases. Patients with iatrogenic causes were older, had poor health and were associated with a higher rate of in-hospital and one-year mortality (59.5% versus 29.6%) (22). Among nondental procedures, only surgery appears to increase the risk in univariate analysis. However, in multivariate analysis, only infectious episodes and skin wounds significantly increased the risk for infectious endocarditis (23).