702. Characteristics of Infective Endocarditis (IE) and Predictors of 90-day Mortality Among People Who Do and Do Not Inject Drugs with IE in Seattle, Washington

Background

People who inject drugs (PWID) are at high risk for IE and account for a growing proportion of IE cases in the United States. We describe key characteristics of IE and predictors of 90-day mortality among people who do and do not inject drug at two large academic medical centers.

Methods

We used a string-searching and pattern-matching algorithm within all discharge (DC) summaries to query the electronic medical record (EMR) for cases of IE among adults ≥18 years of age at two academic medical centers in Seattle, Washington from December 1, 2013 to July 31, 2019. All cases were chart reviewed by a member of the study team to confirm a clinical diagnosis of IE and verify housing and PWID status, the latter defined as any injection drug use in the 3 months prior to admission. Microbiology and valve involvement were extracted from DC summaries and chart-reviewed where needed. Deaths were obtained from Washington state death index, which links to our EMR. Descriptive statistics were used to compare PWID and non-PWID with IE, and Kaplan-Meier log rank tests and Cox proportional hazard models were used to assess for predictors of 90-day mortality.

Results

We identified 387 patients with IE, 44% (n=166) of whom were PWID. When compared to non-PWID, PWID were younger (median age 33 vs. 55 years, p< 0.001) and more likely to be female (48% vs. 31%, p=0.001), homeless (41% vs. 9%, p< 0.001), have coagulase-positive Staphylococcal IE (69% vs. 32%, p< 0.001), and have right sided IE (66% vs. 26%, p< 0.001). Seventeen percent (n=64) of patients died within 90 days of admission, including 14% (n=23) of PWID and 19% (n=41) of non-PWID, with no difference in 90-day mortality between these groups (log-rank p=0.3). In univariate analyses, having left sided IE was the only predictor of 90-day mortality (HR 4.79, 95% CI 2.18 – 10.5).

Conclusion

Despite PWID being significantly younger and having a much higher frequency of right sided IE, they had similar 90-day mortality to non-PWID in this contemporary, urban cohort of hospitalized IE patients.

Table 1. Demographic Characteristics of People Who Do and Do Not Inject Drugs with Infective Endocarditis at Two Seattle Hospitals, 2014 – 2019

Disclosures

All Authors: No reported disclosures

Plasma D-dimer levels and ischaemic lesions in multiple vascular regions can predict occult cancer in patients with cryptogenic stroke

BACKGROUND AND PURPOSE

Cancer patients with cryptogenic stroke often have high plasma D-dimer levels and lesions in multiple vascular regions. Hence, if patients with cryptogenic stroke display such characteristics, occult cancer could be predicted. This study aimed to investigate the clinical characteristics of cryptogenic stroke as the first manifestation of occult cancer and to determine whether plasma D-dimer levels and lesions in multiple vascular regions can predict occult cancer in patients with cryptogenic stroke.

METHODS

Between January 2006 and October 2015, data on 1225 patients with acute ischaemic stroke were extracted from the stroke database of Osaka University Hospital. Among them, 184 patients were classified as having cryptogenic stroke, and 120 patients without a diagnosis of cancer at stroke onset were identified. Clinical variables were analyzed between cryptogenic stroke patients with and without occult cancer.

RESULTS

Among 120 cryptogenic stroke patients without a diagnosis of cancer, 12 patients had occult cancer. The body mass index, hemoglobin levels and albumin levels were lower; plasma D-dimer and high-sensitivity C-reactive protein levels were higher; and lesions in multiple vascular regions were more common in patients with than in those without occult cancer. Multiple logistic regression analysis revealed that plasma D-dimer levels (odds ratio, 3.48; 95% confidence interval, 1.68-8.33; P = 0.002) and lesions in multiple vascular regions (odds ratio, 7.40; 95% confidence interval, 1.70-39.45; P = 0.01) independently predicted occult cancer.

CONCLUSIONS

High plasma D-dimer levels and lesions in multiple vascular regions can be used to predict occult cancer in patients with cryptogenic stroke.

18fluorodeoxyglucose positron emission tomography to detect mediastinal or internal mammary metastases in breast cancer

PURPOSE

To determine the prevalence of suspected disease in the mediastinum and internal mammary (IM) node chain by 18fluorodeoxyglucose (FDG) positron emission tomography (PET), compared with conventional staging by computed tomography (CT) in patients with recurrent or metastatic breast cancer.

PATIENTS AND METHODS

We retrospectively evaluated intrathoracic lymph nodes using FDG PET and CT data in 73 consecutive patients with recurrent or metastatic breast cancer who had both CT and FDG PET within 30 days of each other. In reviews of CT scans, mediastinal nodes measuring 1 cm or greater in the short axis were considered positive. PET was considered positive when there were one or more mediastinal foci of FDG uptake greater than the mediastinal blood pool.

RESULTS

Overall, 40% of patients had abnormal mediastinal or IM FDG uptake consistent with metastases, compared with 23% of patients who had suspiciously enlarged mediastinal or IM nodes by CT. Both FDG PET and CT were positive in 22%. In the subset of 33 patients with assessable follow-up by CT or biopsy, the sensitivity, specificity, and accuracy for nodal disease was 85%, 90%, and 88%, respectively, by FDG PET; 54%, 85%, and 73%, respectively, by prospective interpretation of CT; and 50%, 83%, and 70%, respectively, by blinded observer interpretation of CT. Among patients suspected of having only locoregional disease recurrence (n = 33), 10 had unsuspected mediastinal or IM disease by FDG PET.

CONCLUSION

FDG PET may uncover disease in these nodal regions not recognized by conventional staging methods. Future prospective studies using histopathology for confirmation are needed to validate the preliminary findings of this retrospective study.

Diagnosing pneumonia by physical examination: relevant or relic?

BACKGROUND

The reliability of chest physical examination and the degree of agreement among examiners in diagnosing pneumonia based on these findings are largely unknown.

OBJECTIVES

To determine the accuracy of various physical examination maneuvers in diagnosing pneumonia and to compare the interobserver reliability of the maneuvers among 3 examiners.

METHODS

Fifty-two male patients presenting to the emergency department of a university-affiliated Veterans Affairs medical center with symptoms of lower respiratory tract infection (cough and change in sputum) were prospectively examined. A comprehensive lung physical examination was performed sequentially by 3 physicians who were blind to clinical history, laboratory findings, and x-ray results. Examination findings by lung site and whether the examiner diagnosed pneumonia were recorded on a standard form. Chest x-ray films were read by a radiologist.

RESULTS

Twenty-four patients had pneumonia confirmed by chest x-ray films. Twenty-eight patients did not have pneumonia. Abnormal lung sounds were common in both groups; the most frequently detected were rales in the upright seated position and bronchial breath sounds. Relatively high agreement among examiners (kappa approximately 0.5) occurred for rales in the lateral decubitus position and for wheezes. The 3 examiners' clinical diagnosis of pneumonia had a sensitivity of 47% to 69% and specificity of 58% to 75%.

CONCLUSIONS

The degree of interobserver agreement was highly variable for different physical examination findings. The most valuable examination maneuvers in detecting pneumonia were unilateral rales and rales in the lateral decubitus position. The traditional chest physical examination is not sufficiently accurate on its own to confirm or exclude the diagnosis of pneumonia.

Resection of advanced stage neuroblastoma with the cavitron ultrasonic surgical aspirator

Current protocols for the treatment of neuroblastoma emphasize total or near total resection of tumor to improve survival. This is preferentially performed as a primary procedure, or is attempted at a second-look operation. Unfortunately, this tumor often grows to large size with invasion of the spinal canal, or encasement of major vascular or other retroperitoneal structures. A primary attempt at complete removal may result in difficult-to-control hemorrhage or injury to, or loss of, vital organs. A second-look procedure carries other intrinsic risks. It often must be performed during a period of chemotherapeutically induced hematologic and immunologic suppression. The presence of adhesions and dense scar tissue increases the complexity of the dissection. The Cavitron Ultrasonic Surgical Aspirator (CUSA) combines continuous fragmentation, irrigation, and aspiration in one instrument. Tissues high in water content are selectively fragmented and aspirated, while tissues high in collagen and elastin (such as blood vessels and pseudocapsular walls) are selectively spared. Five patients, two with large pelvic dumbell tumors, two with large intrathoracic tumors, and one with a seemingly unresectable large right adrenal tumor (crossing the midline with extensive aortocaval nodal involvement) had total or near-total resection accomplished using the CUSA. In these patients, initial resection of the relatively soft inner part of the tumor left a collapsed pseudocapsule, which was then removed under greatly improved exposure in a relatively small field. The constant aspiration virtually eliminated tumor spillage. Since most vessels were skeletonized without penetration, total blood loss was minimized. There were no intraoperative or postoperative complications.

Hydronephrosis in childhood--reliability of ultrasound screening

The reliability of gray scale sonography for the screening of hydronephrosis is assessed in a retrospective clinical study of pediatric patients. The sensitivity was 89% and the specificity 95%. Discrepancies between the ultrasound and urographic diagnosis of mild hydronephrosis--which was usually not clinically significant--accounted for all of the errors. False positive studies can be reduced by scanning the kidneys with the bladder empty. False negative examinations may be due to the contrast induced diuresis of the urogram.

Reconstitution of natural cell-mediated cytotoxicity with specific antibodies

The apparent nonselective reactions of natural cell-mediated cytotoxicity (NCMC) are selective when tested by inhibition of cytotoxicity with competitor cells indicating a recognition of specificities by the effector cell. N cells that mediate this NCMC in humans have most of the characteristics of K cells that mediate antibody-dependent, cell-mediated cytotoxicity (ADCC) and possess Fc receptors. IgG antibodies attached loosely to N cells through their Fc region, form part of the class of lymphocytes with surface immunoglobulin. We hypothesized that ADCC and NCMS involved similar mechanisms but with the specificity of NCMC directed by the natural IgG antibodies already attached to N cells. Removal of the antibodies with trypsin and reconstitution with specific anti-HLA antibodies produced specific effector cells supporting the role of antibodies on N cells as directors of specificity in NCMC.

Selective reactions in antibody-dependent cell-mediated cytotoxicity

Selective reactions associated with HLA specificity were sought in antibody-dependent cell-mediated cytotoxic tests against HLA-typed lymphoblastoid lines using operationally monospecific HLA sera and effector cells from healthy individuals. Precise detection of HLA specificities was disturbed by the presence of natural antibodies in HLA antiserum and the effect of the serum and cells on target cell viability. Detection of HLA specificity was improved by absorption of the serum to remove natural antibodies and correction of the results for extraneous cell and serum effects.

Specificities in human cell-mediated cytotoxicity

Specificity of natural cell-mediated cytotoxicity was investigated through selective reactions detected by direct cell-mediated cytotoxicity and by inhibition of cytotoxicity through competition. Assuming that target cells reacting alike in direct cytotoxicity shared common antigens, we classified 10 target cells into three groups by target antigens: TA (target antigen) 1, 2, and 3. Partial confirmation of the three groups was achieved in the cross-competition assay. The distinction of TA 1 as a group was clear but some cross-reactivity existed between TA 2 and TA 3 cells.

Decline of natural nonselective cell-mediated cytotoxicity in patients with tumor progression

Lymphocytes isolated from the blood of patients and healthy donors include a population of cells that destroy target cells in the direct cell-mediated cytotoxic assay with little indication of specificity. This natural reaction is the dominant feature of most cell-mediated cytotoxic tests and, although it appears to be mostly nonselective, it possesses some selective activity. The observed cytotoxicity from these reactions depends mostly on the reactivity of the effector cell; when several effector cells are tested on different target cells, the relative order of activity is usually maintained on the different target cells. When this natural cytotoxicity was analyzed without regard to the type of cancer of the patient or of the target cells, a weak decline in the average reactivity was observed with increasing tumor involvement.