Pacemaker Lead Endocarditis Investigated with Intracardiac Echocardiography: Factors Modulating the Size of Vegetations and Larger Vegetation Embolic Risk during Lead Extraction

Abstract

Lead pacemaker infection is a complication on the rise. An infected oscillating mass attached to the leads (ILV) is a common finding in this setting. Percutaneous extraction of the leads and of the device is the best curative option. However, extraction of leads with large masses can be complicated by pulmonary embolism. The aim of this study was to understand the factors associated with large ILV using a sophisticated ultrasound technique to visualize the masses, namely intracardiac echocardiography (ICE), and investigate whether larger masses induce more complications during and after extraction. Percutaneous lead extraction and peri-procedural ICE were done in 36 patients (pts) (75 ± 11 years old, 74% males). Vegetations (max dimension = 8.2 ± 4.1 mm) in the right cavity were found in 26 of them, mostly adhering to the leads. We subdivided the patients into 2 groups: with vegetation size < 1 cm (18 pts) and vegetation size ≥ 1 cm (8 pts). By univariate analysis, we found that patients in group 1 were more often taking anticoagulation therapy (p = 0.03, Phi (Phi coefficient) = −0.5, OR [odds ratio] 0.071) and had signs of local pocket infection (p = 0.02, Phi = −0.52, OR 0.059) while significantly more patients in group 2 had diabetes (p = 0.08, Phi = 0.566, OR 15); moreover the patients in group 2 showed a trend toward a more frequent positive blood culture (p = 0.08, Phi = 0.39, OR 5.8) and infection with coagulase negative staphylococci (p = 0.06, Phi = 0.46, OR 8.3). At multivariate analysis, only 3 factors (diabetes, younger age and anticoagulation therapy) were independently associated with ILV size: diabetes, associated with larger vegetations (group 2), showed the largest beta value (0.44, p = 0.008); age was inversely correlated with ILV size (beta value = −32, p = 0.038), and anticoagulation therapy (beta value = −029, p = 0.048) was more commonly associated with smaller vegetations (group 1). Larger ILV were not associated with more complications or death during or after the extraction. Conclusion: diabetes, anticoagulation therapy and age are independent predictors of lead vegetation size. The embolic potential of large ILV during extraction was modest, so ILVs >1cm are not a contraindication to percutaneous extraction of infected leads.

Advantages of 18F-FDG PET/CT Imaging over Modified Duke Criteria and Clinical Presumption in Patients with Challenging Suspicion of Infective Endocarditis

“…Intra-cardiac echocardiography (ICE) is a diagnostic alternative, without patient radiation exposure, useful in high clinical suspicion of CIED when TTE and TEE are non-conclusive. However, it rests on an invasive diagnostic technique [ 30 , 31 ].…”

A Novel Clinical Perspective on New Masses after Lead Extraction (Ghosts) by Means of Intracardiac Echocardiography

“…We believe that a thrombotic-fibrotic reaction toward the leads is a major, initial event that has in general been ignored by imaging studies in vivo [ 3 , 22 ]. Now for the first time this crucial aspect of the leads status, regarding both leads encapsulation and parietal fibrotic adhesion previously only assessed by autoptic studies [ 7 , 8 , 10 ], can be evaluated in vivo thanks to the spectacular close up of the lead with no ultrasound beam attenuation obtained with ICE [ 23 , 24 ] ( Figure 1 and Figure 3 ). Two major factors trigger the fibrosis that starts with a thrombotic reaction that then becomes organized [ 7 ]: one is wear of the outer insulation of the leads (made either of polyether polyurethane or silicone), more evident in the intracardiac part of the leads as confirmed with the stereomicroscope [ 9 ] since this is more subjected to hemodynamic forces.…”

“…The reaction to the implant may also be modulated by thrombophilic conditions like diabetes and chronic renal diseases [ 24 ], although these were not found to be associated with a thickened lead. However, in our group patients had only mild renal disease ( Table 1 ) while diabetes showed a positive, but not statistically significant trend ( Table 2 ).…”

“…Only 3 studies [ 3 , 4 , 5 ] have previously dealt with ghosts but suffered from the major limitations that no study was made of lead fibrosis-that is the “Rosetta stone” to understand the ghost origin. Ignoring this major confounder makes their conclusion that the ghosts are related to the endocarditis a possibly spurious association [ 27 ]; this spurious association could perhaps be explained by the fact that lead fibrosis is correlated to both ghosts and also, weakly, perhaps favoring bacterial seeding [ 24 ], to vegetations. This spurious association of ghosts to vegetations was also found, even if only as a trend, in our study ( Table 3 ).…”

“…FC and TL assessment is a very useful marker of lead status, with a potentially important clinical impact. In cases of lead encapsulation, close surveillance to identify lead complications is necessary [ 9 ] and antibiotic prophylaxis should be instituted to prevent patient exposure to transient bacteremia, as an encapsulated lead is more prone to microorganism seeding [ 24 , 29 ].…”