Daniel C. DeSimone

Incidence of Infective Endocarditis Caused by Viridans Group Streptococci Before and After Publication of the 2007 American Heart Association's Endocarditis Prevention Guidelines

Background— The American Heart Association published updated guidelines for infective endocarditis (IE) prevention in 2007 that markedly restricted the use of antibiotic prophylaxis in certain at-risk patients undergoing dental and other invasive procedures. The incidence of IE caused by viridans group streptococci (VGS) in the United States after publication of the 2007 American Heart Association guidelines has not been reported. Methods and Results— We performed a population-based review of all definite or possible cases of VGS-IE using the Rochester Epidemiology Project of Olmsted County, Minnesota. Patient demographics and microbiological data were collected for all VGS-IE cases diagnosed from January 1, 1999, through December 31, 2010. We also examined the Nationwide Inpatient Sample hospital discharge database to determine the number of VGS-IE cases included between 1999 and 2009. We identified 22 cases with VGS-IE in Olmsted County over the 12-year study period. Rates of incidence (per 100 000 person-years) during time intervals of 1999–2002, 2003–2006, and 2007–2010 were 3.19 (95% confidence interval, 1.20–5.17), 2.48 (95% confidence interval, 0.85–4.10), and 0.77 (95% confidence interval, 0.00–1.64), respectively (P=0.061 from Poisson regression). The number of hospital discharges with a VGS-IE diagnosis in the Nationwide Inpatient Sample database during 1999–2002, 2003–2006, and 2007–2009 ranged between 15 318 to 15 938, 16 214 to 17 433, and 14 728 to 15 479, respectively. Conclusions— On the basis of data complete through 2010, there has been no perceivable increase in the incidence of VGS-IE in Olmsted County, Minnesota, since the publication of the 2007 American Heart Association endocarditis prevention guidelines.

Stroke or transient ischemic attack in patients with transvenous pacemaker or defibrillator and echocardiographically detected patent foramen ovale

Background— A patent foramen ovale (PFO) may permit arterial embolization of thrombi that accumulate on the leads of cardiac implantable electronic devices in the right-sided cardiac chambers. We sought to determine whether a PFO increases the risk of stroke/transient ischemic attack (TIA) in patients with endocardial leads. Methods and Results— We retrospectively evaluated all patients who had endocardial leads implanted between January 1, 2000, and October 25, 2010, at Mayo Clinic Rochester. Echocardiography was used to establish definite PFO and non-PFO cohorts. The primary end point of stroke/TIA consistent with a cardioembolic etiology and the secondary end point of mortality during postimplantation follow-up were compared in PFO versus non-PFO patients with the use of Cox proportional hazards models. We analyzed 6075 patients (364 with PFO) followed for a mean 4.7±3.1 years. The primary end point of stroke/TIA was met in 30/364 (8.2%) PFO versus 117/5711 (2.0%) non-PFO patients (hazard ratio, 3.49; 95% confidence interval, 2.33–5.25; P<0.0001). The association of PFO with stroke/TIA remained significant after multivariable adjustment for age, sex, history of stroke/TIA, atrial fibrillation, and baseline aspirin/warfarin use (hazard ratio, 3.30; 95% confidence interval, 2.19–4.96; P<0.0001). There was no significant difference in all-cause mortality between PFO and non-PFO patients (hazard ratio, 0.91; 95% confidence interval, 0.77–1.07; P=0.25). Conclusions— In patients with endocardial leads, the presence of a PFO on routine echocardiography is associated with a substantially increased risk of embolic stroke/TIA. This finding suggests a role of screening for PFOs in patients who require cardiac implantable electronic devices; if a PFO is detected, PFO closure, anticoagulation, or nonvascular lead placement may be considered.

Incidence of Infective Endocarditis Due to Viridans Group Streptococci Before and After the 2007 American Heart Association's Prevention Guidelines: An Extended Evaluation of the Olmsted County, Minnesota, Population and Nationwide Inpatient Sample.

OBJECTIVE To determine whether the incidence of infective endocarditis (IE) due to viridans group streptococci (VGS) increased after the publication of the 2007 American Heart Association (AHA) IE prevention guidelines. PATIENTS AND METHODS We performed a population-based survey of all adults (18 years and older) residing in Olmsted County, Minnesota, from January 1, 1999, through December 31, 2013, to identify definite or possible cases of VGS-IE using the Rochester Epidemiology Project. The National (Nationwide) Inpatient Sample hospital discharge database was examined to determine the number of VGS-IE cases in the United States between 2000 and 2011. RESULTS Rates of incidence (per 100,000 person-years) during the intervals of 1999-2002, 2003-2006, 2007-2010, and 2011-2013 were 3.6 (95% CI, 1.3-5.9), 2.7 (95% CI, 0.9-4.4), 0.7 (95% CI, 0.0-1.6), and 1.5 (95% CI, 0.2-2.9), respectively, reflecting an overall significant decrease (P=.03 from Poisson regression). Likewise, nationwide estimates of hospital discharges with a VGS-IE diagnosis trended downward during 2000-2011, with a mean number per year of 15,853 and 16,157 for 2000-2003 and 2004-2007, respectively, decreasing to 14,231 in 2008-2011 (P=.05 from linear regression using weighted least squares method). CONCLUSION Despite major reductions in the number of indications for antibiotic prophylaxis for invasive dental procedures espoused by the 2007 AHA IE prevention guidelines, both local and national data indicate that the incidence of VGS-IE has not increased.

Efficacy of Antitoxin Therapy in Treating Patients With Foodborne Botulism: A Systematic Review and Meta-analysis of Cases, 1923–2016

Background Botulism is a rare, potentially severe illness, often fatal if not appropriately treated. Data on treatment are sparse. We systematically evaluated the literature on botulinum antitoxin and other treatments. Methods We conducted a systematic literature review of published articles in PubMed via Medline, Web of Science, Embase, Ovid, and Cumulative Index to Nursing and Allied Health Literature, and included all studies that reported on the clinical course and treatment for foodborne botulism. Articles were reviewed by 2 independent reviewers and independently abstracted for treatment type and toxin exposure. We conducted a meta-analysis on the effect of timing of antitoxin administration, antitoxin type, and toxin exposure type. Results We identified 235 articles that met the inclusion criteria, published between 1923 and 2016. Study quality was variable. Few (27%) case series reported sufficient data for inclusion in meta-analysis. Reduced mortality was associated with any antitoxin treatment (odds ratio [OR], 0.16; 95% confidence interval [CI], .09-.30) and antitoxin treatment within 48 hours of illness onset (OR, 0.12; 95% CI, .03-.41). Data did not allow assessment of critical care impact, including ventilator support, on survival. Therapeutic agents other than antitoxin offered no clear benefit. Patient characteristics did not predict poor outcomes. We did not identify an interval beyond which antitoxin was not beneficial. Conclusions Published studies on botulism treatment are relatively sparse and of low quality. Timely administration of antitoxin reduces mortality; despite appropriate treatment with antitoxin, some patients suffer respiratory failure. Prompt antitoxin administration and meticulous intensive care are essential for optimal outcome.

Outcomes in Patients With Cardiovascular Implantable Electronic Device Infection Managed With Chronic Antibiotic Suppression

Background. Most cardiovascular implantable electronic device (CIED) recipients are elderly, have multiple comorbid conditions, and are at increased risk of CIED infection (CIEDI). Current guidelines recommend complete device removal in patients with CIEDI to prevent relapse and mortality. However, comorbidities or other factors may preclude device removal, thus prompting a nonsurgical approach that includes chronic antibiotic suppression (CAS). There are limited data on outcomes of patients receiving CAS for CIEDI. Methods. We retrospectively screened 660 CIEDI cases from 2005 to 2015 using electronic health records and a CIEDI institutional database and identified 48 patients prescribed CAS. Primary outcomes were infection relapse and survival. Results. The median age was 78 years, and 73% (35/48) were male. The median Charlson comorbidity index was 4. Common pathogens were coagulase-negative staphylococci (21%, 10/48) and methicillin-sensitive Staphylococcus aureus (19%, 9/48). At 1 month after hospitalization, 25% (12/48) of patients had died, of whom only 1 initiated CAS; 67% (8/12) of these had staphylococcal infections. Of the 37 patients who initiated CAS, the most common antimicrobials were trimethoprim-sulfamethoxazole, penicillin, and amoxicillin (22%, 8/37 each). Estimated median overall survival was 1.43 years (95% confidence interval, 0.27-2.14), with 18% (6/33 survivors) developing relapse within 1 year. Of the 6 patients who relapsed, 2 (33%) subsequently underwent CIED extraction. Conclusion. CAS is reasonable in select patients who are not candidates for complete device removal for attempted cure of CIEDI. Nevertheless, 1-month mortality in our sample of CAS-eligible patients was high and reflective of high rates of comorbid conditions.

Incidence and Predictors of Infective Endocarditis in Mitral Valve Prolapse: A Population-Based Study

OBJECTIVE To determine the incidence and predictors of infective endocarditis (IE) in a population-based cohort of patients with mitral valve prolapse (MVP). PATIENTS AND METHODS We identified all adult Olmsted County residents with MVP diagnosed by echocardiography from January 1989 to December 1998 and cross-matched them with the Rochester Epidemiology Project-identified Olmsted County cases of IE from January 1, 1986, through December 31, 2006. We retrospectively analyzed and de novo confirmed each IE case using the modified Duke criteria. RESULTS There were 896 Olmsted County residents with echocardiographically diagnosed MVP (mean age, 53±21 years; 565 women [63%]). The mean follow-up period was 11±5 years. The 15-year cohort risk of IE after MVP diagnosis was 1.1%±0.4% (incidence, 86.6 cases per 100,000 person-years; 95% CI, 43.3-173.2 cases per 100,000 person-years); thus, the age- and sex-adjusted relative risk of IE in patients with MVP was 8.1 (95% CI, 3.6-18.0) in comparison to the general population of Olmsted County (P<.001). There were no IE cases in patients without previously diagnosed mitral regurgitation (MR). Conversely, IE incidence was higher in patients with MVP with moderate, moderate-severe, or severe MR (289.5 cases per 100,000 person-years; 95% CI, 108.7-771.2 cases per 100,000 person-years; P=.02 compared with trivial, mild, or mild-moderate MR) and in patients with a flail mitral leaflet (715.5 cases per 100,000 person-years; 95% CI, 178.9-2861.0 cases per 100,000 person-years; P=.02 compared with no flail mitral leaflet). CONCLUSION The population-based incidence of IE in adults with MVP is higher than those previously reported in case-control, tertiary care center studies. Patients with MVP and moderate, moderate-severe, or severe MR or a flail mitral leaflet are at a notable risk of developing IE in comparison with those without MR.

Prosthetic pulmonary valve and pulmonary conduit endocarditis: clinical, microbiological and echocardiographic features in adults.

AIMS To review clinical and microbiological findings in adults with prosthetic pulmonary valve (PPV) or right ventricle to pulmonary artery conduit (RVPAC) infective endocarditis (IE) and to assess the yield of transthoracic (TTE) and transesophageal echocardiography (TEE) as diagnostic tools. METHODS AND RESULTS Seventeen adults (age ≥18 years) with PPV/RVPAC who met diagnostic criteria for definite IE between 2000 and 2015 were included. Median age was 34 years and 29% were females; four patients (24%) had a previous episode of IE. IE occurred a median interval of 5.3 years after PPV/RVPAC insertion; median follow-up time was 206 days. The most common organisms were Staphylococcus aureus (29%), coagulase-negative staphylococci (24%), and streptococcal species (24%). Eleven patients (64.5%) required PPV/RVPAC replacement surgery as consequence of the IE episode. There were three deaths during follow-up; one non-operative and two post-operative. TTE was diagnostic for PPV/RVPAC IE in 10 (62%) and TEE was diagnostic in eight (57%) patients; when combined TTE/TEE were diagnostic in 15 of 17 (88%) cases. Severe PPV/RVPAC obstruction was present at the time of IE diagnosis in nine (53%) and severe regurgitation in five (29%). CONCLUSION PPV/RVPAC IE is associated with significant morbidity, mortality and high risk of requiring operative intervention. TTE and TEE are marginal diagnostic tools when used independently; they should be used as complementary techniques in the evaluation of those patients. Severe PPV/RVPAC stenosis was more common than regurgitation in patients with IE; thus IE should be considered in patients presenting with new PPV/RVPAC obstruction.

Implantable cardiac devices with patent foramen ovale—a risk factor for cardioembolic stroke?

A quarter of patients with implanted cardiac devices have a patent foramen ovale (PFO). Thrombus is frequently noted on intravascular leads that in the presence of a PFO could result in cerebral vascular embolic events. However, whether this mechanism of stroke occurs is not clearly known. We report three patients with PFO, implanted leads with thrombus, and stroke, including a patient where thrombus partially attached to the lead was seen traversing the PFO.

Management of bacteremia in patients living with cardiovascular implantable electronic devices.

Cardiovascular implantable electronic devices (CIEDs) have become a critical component in management of patients with cardiac rhythm disturbances, heart failure, and prevention of sudden cardiac death. However, infection remains a major complication of CIED implantation and is associated with significant morbidity and mortality for device recipients. Early-onset CIED infections frequently originate from the generator pocket, secondary to device or pocket contamination at the time of implantation, and may progress to involve device leads or cardiac valves. However, hematogenous seeding of the device leads from a remote source of bacteremia is not infrequent in patients with late-onset CIED infections. Whereas CIED pocket infection can be diagnosed in the majority of cases based on physical findings at the pulse generator site, device lead infection may only manifest with fever and positive blood cultures. However, not every patient with a CIED and positive blood cultures has underlying CIED lead infection. Consequently, management of bacteremia in a CIED recipient without local signs of infection presents a significant challenge. The risk of underlying CIED lead infection in patients presenting with bacteremia depends on several factors, including the type of microorganism isolated in blood cultures, duration and source of bacteremia, type of CIED, and number of device-related procedures. These risk factors must be considered when making decisions regarding the need for further diagnostic imaging and whether to retain or remove the device. In this article, we review the published data regarding risk of CIED infection in patients presenting with bacteremia and propose an algorithm for appropriate evaluation and management.

Infective Endocarditis Involving the Pulmonary Valve

Pulmonary valve (PV) infective endocarditis (IE) is a rare entity, accounting for 1.5% to 2% of cases of IE. Published data are limited to a few case series and reports. We sought to review the Mayo Clinic experience and describe clinical, echocardiographic, and microbiologic features. We included all patients aged ≥18 years seen from 2000 to 2014 who had a diagnosis of native PV IE and unequivocal echocardiographic involvement of the PV. Nine patients with PV IE were identified. Isolated PV IE was present in 7 (78%) of 9 cases. The median age was 59 years and 22% were women. Three patients had congenital heart disease, 2 had central venous catheters, and 3 had cardiovascular implantable electronic devices. Five patients (56%) received chronic immunosuppressive therapy. Enterococcus faecalis and viridans group streptococci were the most common pathogens, isolated in 22% of cases each. Transthoracic echocardiogram (TTE) and transesophageal echocardiogram (TEE) were done in 6 and 7 patients, respectively. Four patients underwent both procedures. TTE was diagnostic in all cases, but TEE failed to detect PV involvement in 1 patient. Median follow-up was 1.8 years. Five patients (56%) underwent PV replacement. There were no operative deaths. One patient had sudden death during follow-up, unrelated to his PV IE episode. Our results suggest that PV IE is rare but carries significant morbidity. TTE and TEE provide complementary information with TEE providing better visualization of other cardiac structures. Our findings of a high prevalence of immunosuppressive therapy and cardiovascular implantable electronic devices have not been previously reported and deserve further investigation.