Background-Although cardiac device infections (CDIs) are a devastating complication of permanent pacemakers or implantable cardioverter-defibrillators, the incidence of CDI in patients with bacteremia is not well defined. The objective of this study was to determine the incidence of CDI among patients with permanent pacemakers or implantable cardioverter-defibrillators who develop Staphylococcus aureus bacteremia (SAB). Methods and Results-A cohort of all adult patients with SAB and permanent pacemakers or implantable cardioverterdefibrillators over a 6-year period was evaluated prospectively. The overall incidence of confirmed CDI was 15 of 33 (45.4%). Confirmed CDI occurred in 9 of the 12 patients (75%) with early SAB (Ͻ1 year after device placement). Fifteen of 21 patients (71.5%) with late SAB (Ն1 year after device placement) had either confirmed (6 of 21, 28.5%) or possible (9 of 21, 43%) CDI. In 60% of the patients (9 of 15) with confirmed CDI, no local signs or symptoms suggesting generator pocket infection were noted. Conclusions-The incidence of CDI among patients with SAB and cardiac devices is high. Neither physical examination nor echocardiography can exclude the possibility of CDI. In patients with early SAB, the device is usually involved, and Ϸ40% of these patients have obvious clinical signs of cardiac device involvement. Conversely, in patients with late SAB, the cardiac device is rarely the initial source of bacteremia, and there is a paucity of local signs of device involvement. The cardiac device is involved, however, in Ն28% of these patients.

Although polysaccharide intercellular adhesin (PIA) is thought to be crucial in the pathogenesis of prosthetic device infections caused by Staphylococcus epidermidis, its role in prosthetic device infections caused by Staphylococcus aureus is unknown. To assess the clinical impact of PIA production, isolates from 15 prospectively identified cases of S. aureus bacteremia in patients with prosthetic joints (8 infected, 7 uninfected) were characterized for biofilm production, hemagglutination, and the presence of a 419-bp amplification product within icaA. Although icaA was present in all 15 isolates, none of the isolates produced hemagglutination and only one isolate (from a patient with an uninfected prosthetic device) weakly produced biofilm in vitro. These results support the observation that the ica locus is conserved between S. epidermidis and S. aureus and that PIA may be expressed only under in vivo conditions. Future investigations should include animal models to approximate the complex milieu surrounding implanted prosthetic medical devices.

The microbiology, epidemiology, diagnostics, and treatment of infective endocarditis (IE) have changed significantly since the Duke Criteria were published in 1994 and modified in 2000. The International Society for Cardiovascular Infectious Diseases (ISCVID) convened a multidisciplinary Working Group to update the diagnostic criteria for IE. The resulting 2023 Duke-ISCVID IE Criteria propose significant changes, including new microbiology diagnostics (enzyme immunoassay for Bartonella species, PCR, amplicon/metagenomic sequencing, in situ hybridization), imaging ([18F]FDG PET/CT, Cardiac Computed Tomography), and inclusion of intraoperative inspection as a new Major Clinical Criterion. The list of “typical” microorganisms causing IE was expanded and includes pathogens to be considered as typical only in the presence of intracardiac prostheses. The requirements for timing and separate venipunctures for blood cultures were removed. Last, additional predisposing conditions (transcatheter valve implants, endovascular cardiac implantable electronic devices, prior IE) were clarified. These diagnostic criteria should be updated periodically by making the ISCVID-Duke Criteria available online as a “Living Document”.

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Staphylococcus aureus bacteremia (SAB) is a serious and growing problem. A longstanding controversy in infectious diseases has centered around the duration of therapy for patients with SAB. Fortunately, the refinement of echocardiography and the creation of new diagnostic criteria have aided in the diagnosis of infective endocarditis in patients with SAB. These advancements have resulted in the development of an algorithm that combines clinical, microbiologic, and echocardiographic findings to stratify patients with SAB into different treatment regimens.

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Introduction: Revascularization of coronary chronic total occlusions (CTOs) may be indicated for relief of medically refractory angina. Myocardial viability assessment by cardiac magnetic resonance (CMR) may help select patients for CTO intervention. Real-world practice is not well described. Methods: We identified patients who underwent coronary angiography between 2016-2020 at a large tertiary center and had ≥1 CTO. Patients with prior CABG were excluded. We examined rates of CMR and outcomes including revascularization and MACE. Myocardial segments were attributed to a CTO territory and adjudicated following angiographic review of coronary anatomy. Significant CMR viability was defined as <50% transmural delayed enhancement in the CTO territory. Results: We identified 1279 patients (74.1% male, 28.1% Black) who met inclusion criteria. Of these, 36.0% had type 2 diabetes mellitus and 54.9% reported angina pectoris. Over half of patients had CTO of the RCA (56.5%), and 18.5% of patients had CTO in >1 vessel. Non-invasive testing was performed in 38.4% of patients; 10.8% had CMR. Rates of CMR were higher in patients with severely reduced EF (≤35%) compared to those with normal EF (≥55%) (22.1% vs 11.1%; p<0.001). Among those who had CMR, 84.8% of patients showed significant viability in the CTO territory (Fig). CTO PCI was performed in 12.5% of patients, CABG was performed in 24.9%, and 63.2% were managed medically. Patients who had CTO PCI had higher rates of angina versus those without CTO PCI (70.0% vs 52.8%; p<0.001) and were more likely to be on ≥2 anti-anginal medications (30.6% vs 18.9%; p<0.001). CTO PCI technical success was achieved in 69.5% of patients and MACE occurred in 2.3% of cases. Conclusions: Patients with coronary CTOs demonstrate high rates of viability in CTO territories based on CMR. Rates of viability testing and CTO revascularization remain low. Further work is needed to determine the role of CMR and other non-invasive testing in CTO management.

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