Ventricular arrhythmias in patients with immune checkpoint inhibitor myocarditis

Background

Immune checkpoint inhibitor (ICI)-associated myocarditis is associated with a markedly increased risk of morbidity and mortality. The occurrence of ventricular arrhythmias (VA) in patients with ICI-associated myocarditis has not been well characterized.

Purpose

The aim of this study was to determine the characteristics and risk factors for severe VA in patients with ICI myocarditis.

Methods

The cohort consisted of 202 patients with ICI myocarditis. Ventricular arrhythmias were defined as a composite of sustained ventricular tachycardia and ventricular fibrillation. We used a multivariable logistic regression model to test the association between clinical variables and the development of VA.

Results

From a cohort of 202 patients with ICI myocarditis (67±13 years, 35% female, 60% hypertension, 23% diabetes mellitus), 41 (20.3%) developed VA, of which, 33 had VT and 8 had VF. The median time from admission to VF was 144 hours and to VT was 72 hours. A VA occurred in 17.5% of patients with a normal LVEF, and 25% of patients with reduced LVEF. On univariate analysis, a QRS duration >110ms (OR 2.88, 95% CI 1.40 to 6.16, P=0.005) and a QTc duration >470ms were associated with an increased probability of VA (OR 2.58, 95% CI 1.23, 5.41, P=0.012). The association remained significant after adjustment for age and gender. Additionally, a longer time from admission to initiation of corticosteroids was associated with a higher probability of VA (OR 1.06, 95% CI 1.01 to 1.13, P=0.027). The association between the time from admission to administration of corticosteroids and probability of VA remained significant after adjustment for age, gender, and LVEF on admission (OR, 1.06, 95% CI 1.00, 1.13, P=0.037) where each 6-hour delay in the initiation of corticosteroids was associated with a 4% increase in the risk for VA.

Conclusions

Ventricular arrhythmias are common in the setting of ICI myocarditis and are observed in patients presenting with both a preserved and a reduced LVEF. Wider QRS and longer QT at presentation and longer time from admission to initiation of corticosteroids were associated with an increased risk of VA.

Funding Acknowledgement

Type of funding sources: None.

Abstract P2-11-04: Not presented

This abstract was not presented at the symposium.

Smoking has declined but not for all: findings from a study in a rural area of Bangladesh

Smoking is one of the leading causes of death and two-thirds of the world's smokers live in 10 countries, including Bangladesh. This study examines the trend and differentials in smoking in Chakaria, Bangladesh. Data from 2 surveys conducted in 1994 and 2008 in Chakaria were used.

RESULTS

showed that smoking declined from 41% in 1994 to 27% in 2008. However, the decline was lower among the poor and the rate remained the same for the female illiterate. Interventions to prevent smoking need to be designed such that they are effective in disadvantaged groups and do not contribute to widening of socioeconomic inequalities in smoking prevalence and tobacco-related ill health and death.

Natural killer (NK) cells are associated with reduced relapse without increased graft-versus-host disease (GVHD) after allogeneic hematopoetic stem-cell transplantation (HSCT)

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Background: Natural killer cells have potential for anti-leukemia activity after haplo-identical HSCT. However, the role of reconstituted NK cells in relapse and survival after matched HLA-identical HSCT is unknown. We investigated the correlation between NK reconstitution and death, relapse, and GVHD after HSCT. Methods: We prospectively studied NK reconstitution in 123 patients with predominantly high-risk hematologic malignancies. Peripheral blood absolute NK cell count (ANK) was determined by flow cytometry analysis of lymphocytes co-expressing bright staining CD56+ and CD16+. Cluster analysis distinguished patients at engraftment with high ANK (>12.2/mm3) (n=80) and low ANK (n=43), and at 60 days with high ANK (>20/mm3) (n=64) and low ANK (n=26). Primary study endpoints were death, relapse and acute grade II-IV GVHD with median follow up of 360 days (28–1967). A cox proportional hazard model was adjusted for important covariates, including age, transplant conditioning (myeloablative vs. non-myeloablative), graft source (peripheral blood vs. bone marrow), and donor-type (HLA-matched related vs. unrelated), dendritic cell level and absolute neutrophil count. Results: A low ANK at engraftment was significantly associated with death (p=0.03) after non-myeloablative HSCT. Using a selection model, only NK remained in the model, and a low ANK was associated with a 2.5 hazard ratio for subsequent death (p=0.04). Additionally, for the overall cohort, ANK at 60 days was strongly associated with time to death (92% in high vs 65% in low group; LR p=0.0007), at 310 days after HSCT. ANK level at 60 days was strongly associated with time to relapse (n=82, (LR p=0.0001). In a multivariate model, low ANK at 60 days was associated with a 4.2 fold relative risk (RR) of death (1.9, 9.1) and 8.6 RR for time to relapse (3.1, 24.3). Conclusions: High NK cell reconstitution is associated with reduced relapse and death without increased incidence of GVHD after HLA-identical HSCT. Our study suggests that NK may have both a potential anti-tumor effect, as well as be tolerogenic. Measuring NK after HSCT may have novel prognostic and therapeutic implications.

No significant financial relationships to disclose.

Dendritic cell (DC) reconstitution is associated with less opportunistic infections (OI) after allogeneic hematopoetic stem-cell transplantation (HSCT)

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Background: Dendritic cells are key antigen presenting cells which coordinate immune responses against infections. We investigated the correlation between DC reconstitution after HSCT and the onset of OI. Methods: We prospectively studied immune reconstitution of DC in 124 patients with predominantly high-risk hematopoetic malignancies. Peripheral blood underwent flow cytometry analysis for DC, defined as lineage negative, HLA-DR+, CD11c+ and CD123+. Cluster analysis demonstrated patients at engraftment with high DC (>6.92/mm3) (n =68), low DC (n=56), and at 60 days with high DC (>3.95/mm3) (n=48), and low DC (n=43). Primary study endpoint was onset of OI, defined as viral and invasive fungal (proven and probable) OI within 6 months of HSCT. A cox proportional hazard multivariate model was adjusted for important covariates, including age, transplant conditioning (myeloablative vs. non-myeloablative), graft source (peripheral blood vs. bone marrow), donor-type (HLA-matched related vs. unrelated), and ANC. Results: Patients with low DC at engraftment had significantly increased onset of acute grade II-IV GVHD by Kaplan-Meier analysis (p=0.004). Patients with onset of GVHD prior to day 60 were less likely to have high DC (32% with GVHD, 72% without GVHD) (p=0.001). Furthermore, low DC at 60 days was adversely associated with: time to viral OI (p=0.04), time to composite of viral OI and death (p=0.02), time to viral or fungal OI (p=0.009), and time to composite of viral or fungal OI and death (p=0.02). In the Cox model, low DC at 60 days, was associated with a 3.7 relative risk (RR) (1.2, 11.8) for onset of OI. Patients with onset of OI prior to day 60 were significantly less likely to have high DC (41% with OI, 61% without OI) (p=0.05). Conclusions: This study emphasizes the clinical importance of measuring DC after transplant. Patients with low DC reconstitution are at an increased risk of OI and death. Measuring DC, and further understanding of the likely complex factors involved in DC reconstitution, may provide rationale towards future therapeutic immune interventions.

No significant financial relationships to disclose.