Sohail, M Rizwan

AbstractBackgroundAscertaining involvement of left ventricular assist device (LVAD) in a patient presenting with bloodstream infection (BSI) can be challenging, frequently leading to use of chronic antimicrobial suppressive (CAS) therapy. We aimed to assess the efficacy of CAS therapy to prevent relapse of BSI from LVAD and non-LVAD sources.MethodsWe retrospectively screened adults receiving LVAD support from 2010 through 2018, to identify cases of BSI. Bloodstream infection events were classified into LVAD-related, LVAD-associated, and non-LVAD BSIs.ResultsA total of 121 episodes of BSI were identified in 80 patients. Of these, 35 cases in the LVAD-related, 14 in the LVAD-associated, and 46 in the non-LVAD BSI groups completed the recommended initial course of therapy and were evaluated for CAS therapy. Chronic antimicrobial suppressive therapy was prescribed in most of the LVAD-related BSI cases (32 of 35, 91.4%) and 12 (37.5%) experienced relapse. Chronic antimicrobial suppressive therapy was not prescribed in a majority of non-LVAD BSI cases (33, 58.9%), and most (31, 93.9%) did not experience relapse. Chronic antimicrobial suppressive therapy was prescribed in 9 of 14 (64.2%) cases of LVAD-associated BSI and none experienced relapse. Of the 5 cases in this group that were managed without CAS, 2 had relapse.ConclusionsPatients presenting with LVAD-related BSI are at high risk of relapse. Consequently, CAS therapy may be a reasonable approach in the management of these cases. In contrast, routine use of CAS therapy may be unnecessary for non-LVAD BSIs.

Abstract Background Current guidelines from the American Heart Association (AHA) recommend repeating transesophageal echocardiography (TEE) in three to five days if there is high suspicion of IE despite an initial TEE that was negative. This recommendation, however, is based on limited published data. Objectives This investigation attempts to identify specific factors that prompted repeat TEE and evaluate the yield of IE‐related findings demonstrated by repeat TEE as compared to initial or prior TEE. Methods A retrospective cohort who had at least one repeat TEE during an index hospitalization or initial course of antimicrobial therapy for IE between January 2014 and September 2018. We assessed the impact of repeat TEE on IE diagnosis and patient management and included a comparative analysis of patients with initial TEE only. Results Overall, 59 (44.7%) of 132 IE patients underwent repeat TEE. In a comparative analysis that involved patients who had undergone an initial TEE only versus those who had repeat TEE, male gender ( P = .029) and presence of a prosthetic valve or annuloplasty ring ( P = .017) were significantly associated with repeat TEE. Importantly, 8 (17.4%) of repeat TEE were critical for IE diagnosis, 8 (17.4%) impacted antimicrobial management, and 11 (23.9%) supported cardiovascular surgical intervention. Conclusions From a population‐based cohort of incident IE cases, repeat TEE was more frequently (44.7%) done in patients with suspect or proven IE and associated complications than anticipated. Repeat TEE remains pivotal in a contemporary practice that involves critical aspects of IE diagnosis and management.

Abstract Background Approximately one-third of cases of cardiovascular implantable electronic device (CIED) infection present as CIED lead infection. The precise transesophageal echocardiographic (TEE) definition and characterization of “vegetation” associated with CIED lead infection remain unclear. Methods We identified a sample of 25 consecutive cases of CIED lead infection managed at our institution between January 2010 and December 2017. Cases of CIED lead infection were classified using standardized definitions. Similarly, a sample of 25 noninfected patients who underwent TEE that showed a defined lead echodensity during the study period was included as a control group. TEEs were reviewed by 2 independent echocardiologists who were blinded to all linked patient demographic, clinical, and microbiological information. Reported echocardiographic variables of the infected vs noninfected cases were compared, and the overall diagnostic performance was analyzed. Results Descriptions of lead echodensities were variable and there were no significant differences in median echodensity diameter or mobility between infected vs noninfected groups. Among infected cases, blinded echocardiogram reports by either reviewer correctly made a prediction of infection in 6 of 25 (24%). Interechocardiologist agreement was 68%. Sensitivity of blinded TEEs ranged from 31.5% to 37.5%. Conclusions Infectious vs noninfectious lead echodensities could not be reliably distinguished on the basis of size, mobility, and general shape descriptors obtained from a retrospective blinded TEE examination without knowledge of clinical and microbiological parameters. Therefore, a reanalysis of criteria used to support a diagnosis of CIED lead infection may be warranted.

Abstract Background Using synthetic antibiotic‐eluting envelope (ABE) is an effective intervention for prevention of cardiovascular implantable electronic device (CIED) infection. The biologic extracellular‐matrix envelope (ECME), may offer potential advantages over the synthetic ABE. To further minimize the risk of infection, the ECME can be hydrated in gentamicin prior to CIED implantation. We aimed to evaluate the efficacy and pharmacokinetics (PK) of gentamicin containing ECME in an animal model. Methods For all experiments, the ECME was hydrated in gentamicin (40 mg/Ml) (treatment) for 2 min. In vitro antimicrobial efficacy against six different bacterial species was assessed. In vivo experiments were conducted using a rabbit model of CIED pocket infection. Serum and ECM gentamicin concentrations were measured. Five different organisms were inoculated into the device pocket of control (ECME hydrated in 0.9% saline) and treatment groups. Macroscopic appearance and colony forming units from CIED, ECME, and tissue were determined. Results No bacteria were recovered from any culture after 12 h of exposure to the gentamicin containing ECME. Serum gentamicin levels dropped below the limit of quantification at 15 h after implant. Gentamicin concentration in the ECME remained relatively stable for up to 7 days. Signs of clinical infection were observed in the control but not in the treatment group. In the presence of gentamicin, statistically significant reduction was demonstrated across all tested bacterial species. Conclusions In this preclinical animal infection model, gentamicin containing ECME was highly effective in reducing bacterial burden in the implant pocket, while systemic exposure after implantation remained low.

Abstract Introduction Infections of cardiac implantable electronic devices remain a prevalent health concern necessitating the advent of novel preventative strategies. Based on the observation that bacterial infections of the Micra transcatheter pacemaker device are extremely rare, we examine the effect of parylene coating on bacterial adhesion and growth. Methods Bacterial growth was compared on polyurethane coated, bare, or parylene coated titanium surfaces. Eight test samples per bacterial species and material combination were incubated with Staphylococcus Aureus or Pseudomonas aeruginosa for 24 hours and then assayed for bacterial growth. The surface contact angle was also characterized by measuring the angle between the tangent to the surface of a liquid droplet made with the surface of the solid sample. Results The mean bacterial colony counts were significantly reduced for both parylene coated titanium versus bare samples (3.69 ± 0.27 and 4.80 ± 0.48 log[CFU/mL] respectively for S. aureus [ P < .001] and 5.51 ± 0.27 and 6.08 ± 0.11 log[CFU/mL] respectively for P. aeruginosa [ P < .001]), and for parylene coated titanium versus polyurethane samples (4.27 ± 0.42 and 5.40 ± 0.49 log[CFU/mL] respectively for S. aureus [ P < .001] and 4.23 ± 0.42 and 4.84 ± 0.32 log[CFU/mL] respectively for P. aeruginosa [ P = .006]). Parylene coated titanium samples had a higher contact angle compared with bare titanium, but lower compared with polyurethane (mean contact angle 87.5 ± 3.1 degrees parylene, 73.3 ± 3.7 degrees titanium [ P < .001 vs parylene], and 94.8 ± 3.7 degrees polyurethane [ P = .002 vs parylene]). Conclusions Parylene coating significantly reduced the ability of bacteria to grow in colony count assays suggesting that this could contribute to the reduction of bacterial infections of Micra transcatheter pacemakers.

Background Postsurgical complications have been an increasing concern for hospitals, particularly in light of payment reform. The costs to the health care system are increasing in light of Medicare penalties for readmissions for certain conditions. Surgical site infection following implant-based breast reconstruction (IBR) remains challenging. The rates of positive cultures and isolated microorganisms in IBR are unknown. This systematic review summarizes the reported microorganisms and positive culture rates in the existing literature. Methods A systematic review was performed using the guidelines outlined in Preferred Reporting Items for Systematic Reviews and Meta-analyses. Articles were included if breast implant infection rates and culture results were reported. Further subgroup analysis of culture positive infections was performed. Results A total of 25 studies were included, encompassing 25,177 IBR. Implant infections were reported in 1356 reconstructions (5.4%). Cultures were positive in 74.5% of infections. Gram-positive bacteria were the most common (68.6%), of which Staphylococcus species (51%) was the most isolated pathogen, followed by Pseudomonas. A subgroup analysis showed that early infections (63% vs 88%), radiotherapy (82% vs 93%), and acellular dermal matrix use (90% vs 100%) were associated with lower positive culture rates than their respective counterparts. Patients who received chemotherapy had higher positive culture results (94% vs 83%). Isolated microorganisms also varied among the subgroups. Conclusions This systematic review outlines reported microorganisms in IBR. Staphylococcus species and Pseudomonas were the most frequently reported microorganism. Negative cultures were reported in up to 25.5% of infections. Patients with early infections, radiotherapy, and acellular dermal matrix demonstrated higher negative culture rates. This review can help guide the use of empirical antimicrobial therapy in IBR.

A 62-year-old man with essential hypertension and right L4-L5 hemilaminectomy was referred to rheumatology for evaluation of severe arthralgia and myalgia for 12 months. Review of symptoms was significant for night sweats and 20 pounds unintentional weight loss. Physical examination was significant for holosystolic murmur best heard at the cardiac apex of unclear chronicity. Laboratory investigations revealed elevated inflammatory markers, white blood cell count and B-type natriuretic peptide. Transoesophageal echocardiogram showed flail posterior mitral leaflet with severe mitral regurgitation and two vegetations (2.5×1 cm and 1.6×0.3 cm). Abdominal CT showed new focal splenic infarcts, and a brain MRI revealed subacute infarcts, consistent with the embolic phenomenon. Blood cultures grew Granulicatella elegans. The patient underwent mitral valve replacement surgery followed by 6 weeks of parenteral therapy with vancomycin and gentamicin, with full recovery at a 3-month follow-up.