Effects of antineoplastic and immunomodulating agents on postvaccination SARS-CoV-2 breakthrough infections, antibody response, and serological cytokine profile

BACKGROUND

Despite immunization, patients on antineoplastic and immunomodulating agents have a heightened risk of COVID-19 infection. However, accurately attributing this risk to specific medications remains challenging.

METHODS

An observational cohort study from December 11, 2020 to September 22, 2022, within a large healthcare system in San Diego, California, USA was designed to identify medications associated with greatest risk of postimmunization SARS-CoV-2 infection. Adults prescribed WHO Anatomical Therapeutic Chemical (ATC) classified antineoplastic and immunomodulating medications were matched (by age, sex, race, and number of immunizations) with control patients not prescribed these medications yielding a population of 26 724 patients for analysis. From this population, 218 blood samples were collected from an enrolled subset to assess serological response and cytokine profile in relation to immunization.

RESULTS

Prescription of WHO ATC classified antineoplastic and immunomodulatory agents was associated with elevated postimmunization SARS-CoV-2 infection risk (HR 1.50, 95% CI 1.38 to 1.63). While multiple immunization doses demonstrated a decreased association with postimmunization SARS-CoV-2 infection risk, antineoplastic and immunomodulatory treated patients with four doses remained at heightened risk (HR 1.23, 95% CI 1.06 to 1.43). Risk variation was identified among medication subclasses, with PD-1/PD-L1 inhibiting monoclonal antibodies, calcineurin inhibitors, and CD20 monoclonal antibody inhibitors identified to associate with increased risk of postimmunization SARS-CoV-2 infection. Antineoplastic and immunomodulatory treated patients also displayed a reduced IgG antibody response to SARS-CoV-2 epitopes alongside a unique serum cytokine profile.

CONCLUSIONS

Antineoplastic and immunomodulating medications associate with an elevated risk of postimmunization SARS-CoV-2 infection in a drug-specific manner. This comprehensive, unbiased analysis of all WHO ATC classified antineoplastic and immunomodulating medications identifies medications associated with greatest risk. These findings are crucial in guiding and refining vaccination strategies for patients prescribed these treatments, ensuring optimized protection for this susceptible population in future COVID-19 variant surges and potentially for other RNA immunization targets.

Impact of exercise on pulmonary artery pressure in patients with heart failure using an ambulatory pulmonary artery pressure monitor

Background

In this multicenter prospective study, we explored the relationship between pulmonary artery pressure (PAP) at rest and in response to a 6-min walk test (6MWT) in ambulatory patients with heart failure (HF) with an implantable PAP sensor (CardioMEMS, Abbott).

Methods

Between 5/2019 and 2/2021, HF patients with a CardioMEMS sensor were recruited from seven sites. PAP was recorded in the supine and seated position at rest and in the seated position immediately post-exercise.

Results

In our cohort of 66 patients, mean age was 70 ± 12 years, 67% male, left ventricular ejection fraction (LVEF) < 50% in 53%, mean 6MWT distance was 277 ± 95 meters. Resting seated PAPs were 31 ± 15 mmHg (systolic), 13 ± 8 mmHg (diastolic), and 20 ± 11 mmHg (mean). The pressures were lower in the seated rather than the supine position. After 6MWT, the pressures increased to PAP systolic 37 ± 19 mmHg (p < 0.0001), diastolic 15 ± 10 mmHg (p = 0.006), and mean 24 ± 13 mmHg (p < 0.0001). Patients with elevated PAP diastolic at rest (>15 mmHg) demonstrated a greater increase in post-exercise PAP.

Conclusion

The measurement of PAP with CardioMEMS is feasible immediately post-exercise. Despite being well-managed, patients had severely limited functional capacity. We observed a significant increase in PAP with ambulation which was greater in patients with higher baseline pressures.

207. Ineffective Initial Antibiotics for Enteric Bacteremia: Does Every Hour Count with Rapid Diagnostics and Stewardship Intervention?

Background

It has been a long-standing practice to administer broad-spectrum antibiotics early for sepsis as each hour delay is associated with increase in mortality. With increasing rates of antibiotic resistance fueled by unnecessary use of antibiotics, it is delicate to balance the benefits vs consequences of empiric carbapenem therapy. With rapid molecular blood culture diagnostics available, identification of extended-spectrum beta-lactamase (ESBL) producing bacteremia can occur within hours and therapy optimized with active stewardship intervention. With rapid diagnostics, does each hour of ineffective antibiotic therapy really count?

Methods

This multicenter, retrospective, cohort study compared adult inpatients with E. coli bacteremia from a urinary source who received initial effective (EA) vs ineffective antibiotics (IA). The primary outcome was clinical treatment success at day 4. Secondary endpoints included length of stay (LOS), infection-related mortality, incidence of C. difficile infection (CDI), and subgroup analysis of outcomes by ESBL (CTX-M type) vs non-ESBL. Associations with endpoints were assessed using Fisher’s Exact tests using R v. 4.0.3.

Results

Clinical treatment success at day 4 was higher in the EA (n = 488) vs IA (n = 119) groups (93.7% vs 86.6%, p = 0.01) and median LOS was shorter (5 [IQR 4-6] vs 5 [IQR 5-7] days, p &lt; 0.01). There were no differences in infection-related mortality (3.1% vs 3.4%, p = 0.8), 30-day mortality (2.5% vs 2.5%, p &gt; 0.9), or incidence of CDI (1.8% vs 0%, p = 0.3) in the EA vs IA groups, respectively. For patients on IA &lt; 24 h vs &gt; 24 h, there was no difference in clinical improvement at day 4 (86.7% vs 90.5%, p &gt; 0.9) nor 30-day mortality (2.4% vs 4.8%, p = 0.4). Clinical treatment success at day 4 was higher among non-CTX-M (n = 476) vs CTX-M (n = 131) patients (93.9% vs 86.3%, p = 0.01) even among those that received initial EA (94.5% vs 83.3%, p = 0.02). Median LOS was also shorter in CTX-M vs non CTX-M (5 [IQR 4-6] vs 5 [IQR 4-8] days, p &lt; 0.01).

Conclusion

There was no mortality difference among patients receiving initial EA vs IA for E. coli bacteremia with rapid molecular blood culture diagnostics with active stewardship. Therapy for patients on IE is rapidly corrected and stewardship programs can use this intervention to promote judicious use of carbapenems.

Disclosures

All Authors: No reported disclosures

1300. Comparison of Narrow vs. Broad Spectrum Antibiotics for Treatment of Community-acquired Aspiration Pneumonia

Background

Aspiration pneumonia (aspPNA) accounts for 5-15% of pneumonia admissions. Despite the absence of risk factors for organisms such as methicillin-resistant S. aureus (MRSA) or Pseudomonas aeruginosa (PsA), broad-spectrum (BS) antibiotics active against these pathogens are frequently prescribed. We compared outcomes of patients receiving narrow-spectrum (NS) versus BS antibiotics for aspPNA.

Methods

This is a retrospective cohort study of hospitalized patients started on antibiotics for aspPNA upon admission from 1/1/2019 to 12/31/2019. The BS cohort included patients prescribed antibiotics with activity against PsA or MRSA and were on BS antibiotics for &gt; 50% duration of therapy regardless of de-escalation. The primary endpoint was clinical response, defined as resolved, improved, no change, or worsened. Secondary endpoints included 30-day all-cause mortality, duration of therapy, 30-day C. difficile infection, and length of stay. Outcomes were assessed using logistic regression with antibiotic group as a fixed effect, and all analyses were conducted using R v. 4.0.3.

Results

A total of N=95 patients were included in the study, 35 in the NS and 60 in the BS groups. Clinical response was similar in distribution between groups (p &gt; 0.3). 30-day all-cause mortality was lower in the NS (11.4%) as compared to the BS group (33.3%) (OR 0.26; 95% CI 0.09- 0.81; p &lt; 0.04). There were no differences for the secondary endpoints including median duration of therapy (4 [IQR 2.5] days vs. 6 [IQR 6] days, p&gt; 0.2), 30-day C. difficile infection (0% vs 6.7%, p &gt; 0.3), and median length of stay (6 [IQR 5] days vs. 7 [IQR 8.5] days, p &gt; 0.2) in NS vs. BS groups, respectively. A positive blood or respiratory culture was isolated in 37% (35/95) patients. Enteric organisms were the most prevalent bacteria isolated (20%), followed by methicillin susceptible S. aureus (8%), and Streptococcus spp (7%). MRSA and PsA were detected in 2% and 3% of patients, respectively.

Conclusion

There is no difference in efficacy between NS and BS antibiotics for aspPNA. Microbiologic data confirm the low incidence of PsA or MRSA causing aspPNA despite high empiric prescribing of antibiotics active against these pathogens. These results support the ongoing need for targeted antibiotic stewardship initiatives for aspPNA.

Disclosures

All Authors: No reported disclosures

Gender interaction effect on coronary lumen volume to mass ratio after administration of sublingual GTN powder compared to tablet in coronary computed tomography angiography (CCTA)

Funding Acknowledgements

Type of funding sources: None.

Background

Nitroglycerin (GTN) results in improved CCTA image quality and diagnostic accuracy due to vasodilation and improved contrast density. Although studies have shown that sublingual (SL) GTN spray has greater vasodilation and faster onset and duration of action compared to SL tablet, it is not commonly used due to cost. The comparative efficacy of SL GTN powder in CCTA is unknown.

Purpose

The purpose of this study is to determine whether SL GTN powder can increase the coronary lumen volume (V) and the coronary lumen volume to left myocardial mass ratio (V/M) compared to SL GTN tablet.

Methods

34 patients (17 females) with 0.8 mg SL GTN powder and 34 patients (17 females) with 0.8 mg SL GTN tablet administration were included in this retrospective case-control study.  GTN was given 5 minutes pre-CCTA on a 256 slice single-heartbeat CT. Inclusion criteria: CAD-RADS 0 or 1, precontrast LM + LAD AJ-130 CAC &lt; 100, heart rate less than 75, phase of the cardiac cycle diastole, successful motion correction, Likert score 4 or 5, right- or co-dominance. The primary outcome assessed was left main plus left anterior descending (LM + LAD) V between GTN powder vs tablet. The secondary outcomes were LM + LAD V divided by 1) length of LM + LAD (derived mean area, A), and  2) M (V/M). The outcomes were measured by blinded PI with 17 yrs CCTA experience on GE workstation, 2020 version.  Categorical variables were compared by Chi-Squared tests and continuous variables were compared between powder and tablet groups by unpaired t-tests if normally distributed, and Mann-Whitney U tests otherwise. Exploratory outcome analyses tested route of administration by sex interactions and main effects by Two-Way ANOVA’s. Further covariate-adjusted analyses were conducted using multiple linear regression models. 

Results

Baseline characteristics were similar between powder and tablet administration. No statistically significant difference in median V, LM + LAD derived A , or median V/M  was observed. A sex main effect demonstrated that females had significantly smaller V (630.6 mm3 vs 951.7 mm3, p&lt; 0.0001) and A (4.2 mm2 vs 6.4 mm2, p&lt; 0.0001) compared to males. These V and A sex differences were also observed when BMI or weight were included as covariates. When V and A were normalized by M, both revealed sex interactions depending on formulation. While males had higher normalized V and A in powder vs tablet (p &lt; 0.04), females had the opposite with higher normalized V and A with tablet compared to powder (p &lt; 0.04). 

Conclusions

SL administration of the GTN powder 5 minutes before CCTA did not result in greater vasodilatory effect compared to the GTN tablet.  However, gender interaction effects were observed, with greater V/M and A/M ratio in males with powder and greater V/M and A/M in women with tablet. These results suggest a potential differential gender effect based on the formulation of GTN.  Prospective studies are warranted to evaluate these findings.

Abstract Figure. LM + LAD Lumen Volume to LV Mass by Sex

1026. Is Empiric Coverage Necessary? Incidence of Pseudomonas aeruginosa and Methicillin-Resistant Staphylococcus aureus in Foot Infections

Background

Empiric antibiotics for foot infections often include coverage of Pseudomonas aeruginosa (PA) and Methicillin-resistant Staphylococcus aureus (MRSA) due to their presumed frequency and ability to cause severe infection. The purpose of this study was to: 1) determine the incidence of PA and MRSA in foot infections; 2) identify variables associated with the presence of PA or MRSA; and 3) examine empiric antibiotic trends for foot infections to determine if empiric coverage of PA and MRSA is warranted.

Methods

Retrospective study of foot infections at five large urban hospitals in San Diego during 2018. Data were collected from the medical records including demographics, host factors, laboratory data, pathology and imaging data, culture results, and empiric antibiotics. Patients with a foot infection treated as an inpatient in our healthcare system who had a culture collected were included.

Results

310 patients with foot infections were included. Mean age was 61.6 years; 220 (71%) were male; 248 (80%) had diabetes; 40 (13%) had end-stage renal disease (ESRD), and 122 (39%) had peripheral arterial disease (PAD). PA was present in 28 (9%) cases. No patient had a positive blood culture for PA. MRSA was present in 55 (18%) cases. Only one patient had a positive blood culture for MRSA. On univariate analysis, wound location not in the forefoot (p=0.047) and presence of PAD (p=0.048) were associated with PA. These failed to remain significant in multivariate analysis (OR=0.42, p=0.074 and OR=2.54, p=0.0504, respectively). Factors associated with MRSA included shallower depth of wound (OR=0.36; p=0.043). 199/310 patients (64%) received empiric antibiotic coverage for PA while 262/310 patients (85%) received empiric MRSA coverage. Of those who received empiric anti-PA coverage, 174 were overtreated (87%). Of those who received empiric anti-MRSA coverage, 218 (83%) were overtreated.

Conclusion

The incidence of PA in foot infections was overall low, and none had positive blood cultures. MRSA was more often present, however, most patients did not have bacteremia or severe infections. In our study, the majority of empiric anti-PA, as well as anti-MRSA, antibiotic coverage for foot infections was unnecessary questioning the need for upfront, empiric coverage for these pathogens in foot infections.

Disclosures

All Authors: No reported disclosures

193. quality Improvement Initiative for Non-purulent Cellulitis Management in Urgent care setting: provider-level Performance Feedback

Background

Methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a common cause of skin and soft-tissue infections (SSTIs). This has resulted in an 88% increase in MRSA-directed antibiotic use in emergency departments. However, the majority of cellulitis presents as non-purulent due to Group A streptococci. An unintended consequence is that many with non-purulent cellulitis receive sub-optimal antibiotics and unnecessary diagnostics. Clinical guidelines at our institution recommend beta-lactam antibiotics and discourage empiric MRSA coverage for non-purulent cellulitis. The aim of this study is to use an audit-feedback intervention to optimize urgent care providers management of mild/moderate non-purulent cellulitis.

Methods

We identified all consecutive patients presenting to our urgent care with a diagnosis of lower extremity non-purulent cellulitis using ICD coding. We conducted a prospective pre and post-intervention study from 10/2018-3/2019 and 11/2019-4/2020 respectively. Intervention included review of practice guidelines with providers and feedback from pre-intervention phase. To assess individual practitioners’ prescribing habits, a comprehensive scoring system focused on empiric antibiotic selection, antibiotic duration, and diagnostics was combined with patient demographics. Scores classified non-purulent SSTI treatment as follows: 0–2 = good, 2.5–5 = fair, and >5.5 = poor (Figure 1).

Figure 1: Provider Cellulitis Management Scoring Sheet

Results

There was statistically significant provider score improvement in the post-intervention phase with greater percentage of good cases (40% to 69%) and no poor cases (Figure 2). For IV antibiotics for mild and moderate cellulitis, there was decreased use of overly broad antibiotics (Figure 3). Antibiotic duration of greater than 7 days decreased from 68% to 52%. Combination antibiotic therapy decreased from 12% to 4%. There was also a statistically significant decrease in use of wound cultures but no change in ultrasound use.

Figure 2: Overall Provider Scores

Figure 3: IV Antibiotic Use

Conclusion

Audit-feedback intervention was effective for improving antibiotic usage and decreasing treatment duration. Providing physicians with data on their practice patterns relative to those of their peers and clinical practice guidelines can improve management of non-purulent cellulitis.

Disclosures

All Authors: No reported disclosures

Safety and efficacy of pharmacologic weight loss in patients with cirrhosis

Background

Obesity poses unique risks in patients with advanced liver fibrosis; however, given surgical risks of bariatric surgery in cirrhosis treatment recommendations are currently limited to lifestyle interventions. This study seeks to inform a potential treatment gap by describing the safety and efficacy of pharmacologic weight loss in patients with advanced liver disease.

Methods

A retrospective chart review of the electronic medical record was conducted for all patients in the Scripps Health system from 2005 to 2017 with established advanced liver fibrosis that were prescribed medications associated with weight loss. The primary outcome was safety as defined by the model for end-stage liver disease (MELD) score. Secondary outcomes included total body weight loss, reasons for medication discontinuation, medication adverse events, and hospitalization before and after medication initiation.

Results

Thirty-eight patients and 63 prescriptions were included in the final analysis. The most frequently prescribed medication associated with weight loss was metformin (63%, n = 24) followed by a GLP-1 agonist (39%, n = 15). There was no significant effect of weight-loss medication on MELD score (p > 0.18) or number of hospitalizations when adjusting for subject (p > 0.26). There was a significant adjusted mean weight loss of 2.2 kg (p < 0.02) following prescription of a medication associated with weight loss. The Federal Drug Administration-approved anti-obesity medications as a group resulted in a significant adjusted weight loss of 7.22 kg (p < 0.013). In a linear mixed-effects model accounting for subjects, weight loss was not independently associated with a change in MELD (t[51] = -1.972, p > 0.05).

Conclusion

Pharmacologic weight loss in patients with advanced liver fibrosis appears feasible based on preliminary safety and efficacy outcomes in this study. Future prospective studies are warranted to evaluate a potential significant treatment gap in the management of obesity in this vulnerable population.