A retrospective analysis of anticoagulant safety among heart transplant recipients undergoing endomyocardial biopsy

BACKGROUND

Transvenous endomyocardial biopsy is an invasive procedure which is used to diagnose rejection following an orthotopic heart transplant. Endomyocardial biopsy is widely regarded as low risk with all-cause complication rates below 5% in most safety studies. Following transplant, some patients require therapeutic anticoagulation. It is unknown whether anticoagulation increases endomyocardial biopsy bleeding risk.

METHODS

Records from 2061 endomyocardial biopsies performed for post-transplant rejection surveillance at our institution between November 2016 and August 2022 were reviewed. Bleeding complications were defined as vascular access-related hematoma or bleeding, procedure-related red blood cell transfusion, and new pericardial effusion. Relative risk and small sample-adjusted 95% confidence interval was calculated to investigate the association between bleeding complications and anticoagulation.

RESULTS AND CONCLUSIONS

The overall risk of bleeding was 1.2% (25/2061 cases). There was a statistically significant increase in bleeding among patients on intravenous (RR 4.46, CI 1.09-18.32) but not oral anticoagulants (RR .62, CI .15-2.63) compared to patients without anticoagulant exposure. There was a trend toward increased bleeding among patients taking warfarin with INR ≥ 1.8 (RR 3.74, CI .90-15.43). Importantly, no bleeding events occurred in patients taking direct oral anticoagulants such as apixaban. Based on these results, intravenous rather than oral anticoagulation was associated with a significantly higher risk of bleeding complications following endomyocardial biopsy.

Fulminant Myocarditis Following SARS-CoV-2 Infection

A 60-year-old woman with a past medical history of asthma presented with fulminant myocarditis 9 days after testing positive for SARS-CoV-2 and 16 days after developing symptoms consistent with COVID-19. Her hospital course was complicated by the need for veno-arterial extracorporeal membrane oxygenation, ventricular arrhythmias, and pseudomonas bacteremia. She ultimately recovered and was discharged to home with normal left ventricular systolic function. Thereafter, she developed symptomatic ventricular tachycardia, for which she received an implantable cardioverter-defibrillator and antiarrhythmic drug therapy.

Abstract P302: Neuroimaging Embolic Infarct Pattern in Work-Up For Embolic Source of Undetermined Etiology in Acute Ischemic Stroke

Introduction: Embolic infarct pattern on Neuroimaging as a marker for positive cardioembolism results in the work-up for Embolic Source of Undetermined Etiology (ESUS) in acute ischemic stroke (AIS) is unclear.

Methods: Among 1625 acute ischemic stroke (AIS) hospitalized at our academic stroke program from July 2017 to April 2019, 350 (21.5%) had complete ESUS work-up performed (defined as including TEE and cardiac monitoring). Data was abstracted on demographics, medical history, initial National Institutes of Health Stroke Scale (NIHSS), systolic blood pressure (SBP), troponin level, neuroimaging findings, and cardiac test results. Positive ESUS work-up for cardioembolism was defined as results that prompted management change. Embolic infarct pattern was defined as infarct confirmed on neuroimaging to affect 2 or more vessel territories.

Results: Among 350 with complete ESUS work-up performed, the mean age was 59.0 (range, 23 to 88) and 170 (48.6%) were female. The mean initial NIHSS was 5.4 (range, 0 to 32). Neuroimaging infarct pattern suggested embolic pattern in 75 (21.4%), single vessel pattern in 274 (78.3%), and not visible in 1 (0.3%). Among 274 with single vessel infarct pattern on neuroimaging, affected territory was MCA in 184, Vertebrobasilar in 46, PCA in 34, and ACA in 10. Cardioembolism source was identified in 96 (27.4%) of patients with completed ESUS work-up (7.1% had positive findings on TEE and 20.3% had new-atrial fibrillation diagnosed on cardiac monitoring). Compared to patients with single territory infarct pattern, patients with embolic pattern were more likely to have a history of diabetes mellitus (44.0% vs 31.3%, p 0.0392), higher SBP (159.0 vs 147.9mm Hg, p 0.002) and higher troponin (0.87 vs 0.07 ng/mL, p 0.0124), but there was no significant difference based upon age, sex, history of hypertension, initial NIHSS, HgbA1c, LDL, or rate of positive ESUS work up for cardioembolism (22.7% vs 28.5%, p 0.0088).

Conclusion: Among AIS patients with complete ESUS work-up, the most common neuroimaging pattern was single territory MCA infarct (52.6%) followed by embolic infarct pattern (21.4%). Embolic pattern did not increase the positive yield of ESUS work-up for cardioembolism.

The educational preparation of nurses in a developing economy and patient mortality

BACKGROUND

Most studies have reported that higher levels (baccalaureate degree) of educational attainment by nurses are associated with lower levels of patient mortality. Researchers working in developed economies (e.g. North America and Europe) have almost exclusively conducted these studies. The value of baccalaureate nurse education has not been tested in countries with a developing economy.

METHOD

A retrospective observational study conducted in seven hospitals. Patient mortality was the main outcome of interest. Anonymized data were extracted from nurses and patients from two different administrative sources and linked using the staff identification number that exists in both systems. We used bivariate logistic regression models to test the association between mortality and the educational attainment of the admitting nurse (responsible for assessment and care planning).

RESULTS

Data were extracted for 11 918 (12, 830 admissions) patients and 7415 nurses over the first 6 months of 2015. The majority of nurses were educated in South Asia and just over half were educated to at least bachelor degree level. After adjusting for confounding and clustering, nurse education was not found to be associated with mortality.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Our observations may suggest that in a developing economy, the academic level of nurses' education is not associated with a reduction in patient mortality. Findings should be interpreted with considerable caution but do challenge widely held assumptions about the value of baccalaureate-prepared nurses. Further research focused on nursing education in developing economies is required to inform health policy and planning.

Implementing a nursing systems framework in a developing country

AIM

To test the effect on patient mortality of implementing a nursing systems framework across a national health system.

BACKGROUND

There have been five previous observational studies that have tested the effect of a nursing systems framework on clinical outcomes for patients. Implementation of a nursing systems framework in the health system of a developing country has not been evaluated.

DESIGN

Quasi-experimental (before and after) study.

METHOD

A nursing systems framework consisting of six themes: (i) Professionalisation; (ii) Education; (iii) Structure; (iv) Quality of nursing care; (v) An academic health system; and (vi) Communication (Professional), was implemented across the national health system of Qatar in March 2015. Routine administrative data were extracted (March 2014-February 2016) for elective admissions. Our primary and secondary outcomes were, respectively, all cause mortality at discharge and readmission to hospital (within 28 days of discharge). We split the data into two time periods: before (March 2014-February 2015) and after (March 2015-February 2016) the implementation of the nursing systems framework. Multivariable regression modelling was used to examine the effect of the framework on patient mortality, after adjusting for key confounding variables (patient age, episode acuity, intensive care admission and length of stay).

FINDINGS

Data were extracted for 318 548 patients (year 1 = 130 829; year 2 = 187 725). After adjusting for confounding, there was a significant association between the implementation of the nursing systems framework, mortality and readmission.

CONCLUSION AND IMPLICATIONS FOR NURSING POLICY AND PRACTICE

Our observations suggest that the implementation of a nursing systems framework may be important in improving outcomes for patients in emerging health systems.

Response of canine coronary collateral vessels to ergonovine and alpha-adrenergic stimulation

The ability of moderately well-developed coronary collateral vessels to undergo vasoconstriction in response to alpha-adrenergic stimulation and to ergonovine was studied. Studies were performed in 15 dogs 4-16 wk after embolic occlusion of the left anterior descending coronary artery had been performed to stimulate collateral vessel growth. Interarterial collateral flow was measured as retrograde flow from the cannulated left anterior descending coronary artery, while microvascular collateral flow was measured as continuing tissue flow determined with radioactive microspheres administered during the retrograde flow collection. Studies were performed after beta-adrenergic blockade with propranolol. Neither cardiac sympathetic nerve stimulation nor alpha 1-adrenergic stimulation with phenylephrine caused significant change in retrograde blood flow or myocardial tissue flow. The selective alpha 2-adrenergic agonist, B-HT 933, decreased tissue flow in the collateral-dependent region but did not significantly alter retrograde flow. Although these data indicate that intramural microvascular collateral communications are capable of vasoconstriction in response to alpha 2-adrenergic stimulation, the larger interarterial collaterals are unresponsive to alpha-adrenergic influences. However, under the conditions of the experiment, adrenergic activity did not appear to influence collateral function, since neither alpha 1-adrenergic blockade with prazosin nor alpha 2-adrenergic blockade with rauwolscine altered collateral flow. Ergonovine, 0.2-0.8 microgram.kg-1.min-1, caused a 22 +/- 4% decrease in retrograde flow (P less than 0.01) but did not alter microvascular collateral flow. Thus, of the agents tested, only ergonovine caused vasoconstriction of the large interarterial coronary collateral vessels.

Effect of atrial natriuretic peptide on coronary collateral blood flow

This study was carried out to examine the effects of atrial natriuretic peptide on coronary collateral blood flow. Studies were performed in nine adult mongrel dogs 3.4 months after embolic occlusion of the left anterior descending coronary artery had been performed to stimulate collateral vessel growth. At the time of study the anterior descending coronary artery was cannulated to allow estimation of interarterial collateral flow from measurements of retrograde blood flow. Injection of radioactive microspheres during retrograde flow collection allowed simultaneous determination of continuing tissue flow for evaluation of microvascular collateral communications. Atrial natriuretic peptide in doses of 20 and 200 micrograms administered into the left atrium resulted in 17 +/- 3.0% and 34 +/- 4.5% increases in retrograde flow, respectively (each p less than 0.01). Tissue flow in the collateral dependent myocardial region did not change in response to atrial natriuretic peptide. After the larger dose of atrial natriuretic peptide, the administration of nitroglycerin (10 micrograms/kg into the left atrium) caused no further increase of retrograde blood flow, and no further decrease of collateral vascular resistance. These data indicate that atrial natriuretic peptide causes vasodilation of moderately well-developed interarterial coronary collateral vessels.

Antibody response of mice to lactate dehydrogenase-elevating virus during infection and immunization with inactivated virus

BALB/c and Swiss mice were infected with lactate dehydrogenase-elevating virus (LDV) or immunized with glutaraldehyde-inactivated or ether-extracted virus and their plasma was monitored for anti-LDV IgG and IgM levels by ELISA and indirect fluorescent antibody staining, for neutralizing antibodies, for sensitized antibody-virus complexes, for immune complexes, and for total plasma IgG and IgM. In infected mice, anti-LDV IgM was transiently formed during the first 2 weeks post infection (p.i.) but only at a low level. Anti-LDV IgG was produced in a biphasic manner with an initial peak at about 10 days p.i. and a secondary rise reaching a maximum level 30-80 days p.i. which was retained throughout the persistent phase of infection. The concomitant appearance of comparable levels of low molecular weight immune complexes suggests that most anti-LDV IgG was complexed with LDV proteins. Also, as early as 10 days p.i., infectious antibody-LDV complexes developed, which were neutralizable by rabbit anti-mouse IgG, whereas antibodies that neutralize the infectivity of exogenously added LDV appeared only 1-2 months p.i. Throughout infection, most of the anti-LDV IgG was directed to VP-3, the envelope glycoprotein of LDV, which was found to exist in at least 10 distinct forms ranging in molecular weight from 24 to 42 kDa. Anti-LDV IgG levels as high as those observed in infected mice developed in mice immunized with inactivated LDV. Antibodies to glutaraldehyde-inactivated LDV were also mainly directed to VP-3, but exhibited no neutralizing activity. The polyclonal B cell activation associated with a persistent LDV infection and the formation of immune complexes were not observed in mice immunized with inactivated virus.