Baddour, Larry M.

AbstractBackgroundCefazolin is used as standard preoperative prophylaxis for a variety of surgical procedures that involve the skin. In contrast, vancomycin is recommended for a minority of patients, specifically those with an IgE‐mediated allergy to beta‐lactams and considered in patients with known colonization with methicillin‐resistant Staphylococcus aureus or at high risk for such. Vancomycin, however, has been overprescribed, has nephrotoxicity risk, and may be less effective due to its inferior coverage of methicillin‐susceptible S. aureus and lack of Gram‐negative coverage. This study was performed to assess whether vancomycin use was associated with an increased incidence of cardiovascular implantable electronic device infection (CIEDI) as compared to that of cefazolin or other antistaphylococcal beta‐lactam antibiotics.MethodsThe VA Informatics and Computing Infrastructure database, which included all veterans who underwent CIED placement or revision between 2008 and 2015, was used. A logistic regression model was constructed to estimate the adjusted odds of CIEDI.ResultsOverall, 10,454 CIED procedures were included, and 98% of them were performed in men with a mean age of 71 ± 12 years. The logistic regression analysis showed that vancomycin use alone or in combination with other antibiotics was associated with an increased risk of CIEDI (odds ratio 2.99 [1.76–5.06], P‐value < 0.001), after controlling for other effects.ConclusionsOur study revealed that among patients who received surgical site infection prophylaxis for CIED placement or revision, there was: (1) an unanticipated high rate of vancomycin use, and (2) a threefold increase in the incidence of subsequent CIEDI among vancomycin recipient

AbstractBackgroundCulture‐negative (CN) cardiovascular implantable electronic device (CIED) infections represent a significant management challenge for clinicians with no specific guidelines addressing this subgroup of patients. The aim of the current investigation is to report our institutional experience of CN CIED infections and propose a systematic approach to diagnostic evaluation and management of these complicated cases based on our observations.MethodsWe retrospectively screened all CIED infection cases at Mayo Clinic from 2005 through 2017. Using standardized criteria to define significant microbial growth, all patients with positive blood or pocket/device cultures were excluded.ResultsA total of 835 cases of CIED infection were screened, and of these, 47 (6%) met CN‐CIED infection criteria. Majority of patients (77%) in this cohort had received antimicrobial therapy prior to device cultures with a median duration of 8 days. The most common presentation was device pocket infection (81%). All patients underwent device removal. Route of antibiotics was switched from oral to parenteral and spectrum of activity expanded from initial therapy in 23% of patients despite negative cultures. Majority of patients (80%) were dismissed on parenteral therapy. Adverse events attributed to intravenous antibiotic therapy were documented in 63% of the cases. No recurrence was reported and 6‐month survival was 94.8%.ConclusionsPocket and device cultures in suspected CIED infections may be negative due to preextraction oral antibiotics. However, frequently these patients are managed with broad‐spectrum parenteral therapy postextraction.

Objective To explore differences in clinical manifestations and outcomes in those patients who develop infection after undergoing initial implantation versus reoperation. Methods We compared cases of cardiac implantable electronic device (CIED) infection based on initial implantation versus reoperation from 11 centres. Results There were 432 patients with CIED infection, 178 occurring after initial device placement and 254 after repeat reoperation. No differences were seen in age, sex or device type. Those with infection after initial implant had a higher Charlson Comorbidity Score (median 3 (IQR 2–6) vs 2 (IQR 1–4), p<0.001), shorter time since last procedure (median 8.9 months (IQR 0.9–33.3) vs 19.5 months (IQR 1.1–62.9), p<0.0001) and fewer leads (2.0±0.6vs 2.5±0.9, p<0.001). Pocket infections were more likely to occur after a reoperation (70.1%vs48.9%, p<0.001) and coagulase negative staphylococci (CoNS) was the most frequently isolated organism in this group (p=0.029). In contrast, initial implant infections were more likely to present with higher white cell count (10.5±5.1 g/dL vs 9.5±5.4 g/dL, p=0.025), metastatic foci of infection (16.9%vs8.7%, p=0.016) and sepsis (30.9%vs19.3%, p=0.006). There were no differences in in-hospital (7.9%vs5.2%, p=0.31) or 6-month mortality (21.9%vs14.0%, p=0.056). Conclusions CIED infections after initial device implant occur earlier, more aggressively, and often due to Staphylococcus aureus. In contrast, CIED infections after reoperation occur later, are due to CoNS, and have more indolent manifestations with primary localisation to the pocket.

AbstractBackgroundPublished guidelines mandate complete device removal in cases of cardiovascular implantable electronic device (CIED) infection. Clinical predictors of successful salvage of infected CIEDs have not been defined.MethodsData from the Multicenter Electrophysiologic Device Infection Collaboration, a prospective, observational, multinational cohort study of CIED infection, were used to investigate whether clinical predictors of successful salvage of infected devices could be identified.ResultsOf 433 adult patients with CIED infections, 306 (71%) underwent immediate device explantation. Medical management with device retention and antimicrobial therapy was initially attempted in 127 patients (29%). “Early failure” of attempted salvage occurred in 74 patients (58%) who subsequently underwent device explantation during the index hospitalization. The remaining 53 patients (42%) in the attempted salvage group retained their CIED. Twenty‐six (49%) had resolution of CIED infection (successful salvage group) whereas 27 patients (51%) experienced “late” salvage failure. Upon comparing the salvage failure group, early and late (N = 101), to the group experiencing successful salvage of an infected CIED (N = 26), no clinical or laboratory predictors of successful salvage were identified. However, by univariate analysis, coagulase‐negative staphylococci as infecting pathogens (P = 0.0439) and the presence of a lead vegetation (P = 0.024) were associated with overall failed salvage.ConclusionsIn patients with definite CIED infections, clinical and laboratory variables cannot predict successful device salvage. Until new data are forthcoming, device explantation should remain a mandatory and early management intervention in patients with CIED infection in keeping with existing expert guidelines unless medical contraindications exist or patients refuse device removal.

AbstractBackgroundThe rate of cardiovascular implantable electronic device infection (CIEDI) has increased, despite the use of perioperative antibiotics at the time of device placement or revision. This is due, in part, to the presence of multiple comorbid conditions in an elderly population, in general, who require CIED. Statins may have an antibacterial effect, although there is currently no evidence that the likelihood of CIEDI has been impacted by statin use.MethodsA retrospective cohort study was performed to assess whether statins are associated with a reduced risk of CIEDI. The VA Informatics and Computing Infrastructure (VINCI) database, which includes all veterans who underwent CIED placement between 2008 and 2015, was used. A logistic regression model was constructed to estimate the adjusted risk of CIEDI among patients who were receiving statins after adjusting for confounding factors.ResultsOverall, 18,970 CIED procedures were included, and 98% of them were performed in men with a mean age of 71 ± 11 years. The rate of diabetes mellitus, heart failure, advanced chronic kidney diseases, CIEDI, positive methicillin‐resistant Staphylococcus aureus nasal colonization, and statin use were 23%, 15.7%, 3.3%, 1.14%, 12.6%, and 56%, respectively. The logistic regression analysis showed that statins were significantly associated with a reduced risk of CIEDI; after controlling for other effects, the reduction was 66% (odds ratio 0.34 [0.2–0.59], P‐value < 0.001). The effect of statins was confirmed by propensity score analysis.ConclusionsOur study showed that among patients receiving statins who had undergone CIED placement, there was a 66% reduction in subsequent CIEDI.

Infection is a serious complication of left ventricular assist device (LVAD) therapy. However, an optimal antimicrobial surgical infection prophylaxis (SIP) regimen for LVAD implantation is not well established. We retrospectively reviewed all adults who underwent continuous-flow LVAD implantation from February 2007 to March 2015 at Mayo Clinic Rochester. Left ventricular assist device infection (LVADI) was defined using criteria published by the International Society for Heart and Lung Transplant. Patients excluded from the analysis included those who did not have HeartMate II or HeartWare device, patients with incomplete documentation of SIP, and those with an actively treated infection at the time of LVAD implantation. We compared risk of LVAD-specific and LVAD-related infections and all-cause mortality between SIP regimens at postoperative day 90 and 1 year using Kaplan–Meier time-to-event analyses. During study period, 239 adults underwent continuous-flow LVAD implantation at our institution where 199 patients received single-drug and 40 received multidrug SIP regimen. Median patient age was 62 years. Left ventricular assist device infection occurred in three patients (1.5%) in the single-drug group versus two patients (5.0%) in the multidrug group at 90 days (p = 0.4). There was no difference in infection-free (p = 0.4) and overall survival (p = 0.9) between two groups at 1 year. In conclusion, there was no clear benefit of using multidrug regimen as it did not impact infection-free survival or all-cause mortality compared with single-drug regimen. Prospective clinical trials are needed to further define the optimal SIP regimen for LVAD implantation.

Left ventricular assist devices (LVADs) are becoming a more frequent life-support intervention. Gaining an understanding of risk factors for infection and management strategies is important for treating these patients. We conducted a systematic review and meta-analysis of studies describing infections in continuous-flow LVADs. We evaluated incidence, risk factors, associated microorganisms, and outcomes by type of device and patient characteristics. Our search identified 90 distinct studies that reported LVAD infections and outcomes. Younger age and higher body mass index were associated with higher rates of LVAD infections. Driveline infections were the most common infection reported and the easiest to treat with fewest long-term consequences. Bloodstream infections were not reported as often, but they were associated with stroke and mortality. Treatment strategies varied and did not show a consistent best approach. LVAD infections are a significant cause of morbidity and mortality in LVAD patients. Most research comes from secondary analyses of other LVAD studies. The lack of infection-oriented research leaves several areas understudied. In particular, bloodstream infections in this population merit further research. Providers need more research studies to make evidence-based decisions about the prevention and treatment of LVAD infections.

Abstract Aims There are scant comparative data quantifying the risk of infective endocarditis (IE) and associated mortality in individuals with predisposing cardiac conditions. Methods and results English hospital admissions for conditions associated with increased IE risk were followed for 5 years to quantify subsequent IE admissions. The 5-year risk of IE or dying during an IE admission was calculated for each condition and compared with the entire English population as a control. Infective endocarditis incidence in the English population was 36.2/million/year. In comparison, patients with a previous history of IE had the highest risk of recurrence or dying during an IE admission [odds ratio (OR) 266 and 215, respectively]. These risks were also high in patients with prosthetic valves (OR 70 and 62) and previous valve repair (OR 77 and 60). Patients with congenital valve anomalies (currently considered ‘moderate risk’) had similar levels of risk (OR 66 and 57) and risks in other ‘moderate-risk’ conditions were not much lower. Congenital heart conditions (CHCs) repaired with prosthetic material (currently considered ‘high risk’ for 6 months following surgery) had lower risk than all ‘moderate-risk’ conditions—even in the first 6 months. Infective endocarditis risk was also significant in patients with cardiovascular implantable electronic devices. Conclusion These data confirm the high IE risk of patients with a history of previous IE, valve replacement, or repair. However, IE risk in some ‘moderate-risk’ patients was similar to that of several ‘high-risk’ conditions and higher than repaired CHC. Guidelines for the risk stratification of conditions predisposing to IE may require re-evaluation.