The long-term contemporary outcomes of patients with immune checkpoint inhibitor (ICI) myocarditis, spanning the spectrum of clinical severity, are undetermined. We sought to investigate the characteristics and cardiovascular outcomes of patients with severe and nonsevere ICI myocarditis. This was a retrospective cohort study of patients with suspected ICI myocarditis at Massachusetts General Brigham Health System conducted between 2015 and 2022. Cases were classified as severe, nonsevere, and negative based on the International Cardio-Oncology Society criteria. One-year cardiovascular mortality, all-cause mortality, and cardiovascular readmissions were evaluated. We also evaluated 1-year ICI resumption and left ventricular ejection fraction over a median follow-up of 18 (Q1-Q3: 8-67) weeks. The study included 160 patients: 28 severe, 96 nonsevere, and 36 negative cases. Patients with severe myocarditis had an increased risk of 1-year cardiovascular mortality, particularly in the early post-myocarditis period (29% vs 5%; HR: 6.52; 95% CI: 2.2-19.6; P < 0.001). Patients with nonsevere myocarditis had a cardiovascular mortality rate similar to negative cases (HR: 0.61; 95% CI: 0.14-2.54). One-year all-cause mortality did not differ between severe, nonsevere, and negative cases (P = 0.74). Rates of 1-year cardiovascular readmissions and long-term left ventricular ejection fraction were also similar among the 3 groups. ICI resumption was low, even in negative cases. In a contemporary analysis of patients with suspected ICI myocarditis, severe ICI myocarditis was associated with increased 1-year cardiovascular mortality, which was lower than previously reported. Patients with nonsevere ICI myocarditis had outcomes similar to negative cases. The optimal management strategies for nonsevere ICI myocarditis need to be re-evaluated.

High admission blood glucose (ABG) level has been associated with a poor short-term outcome among non-diabetic patients with heart failure (HF). We aimed to investigate the association between ABG levels and long-term (10 years) mortality in patients with or without pre-existing diabetes mellitus (DM) admitted with HF. We analyzed data on 1811 patients with DM and 2182 patients without pre-existing DM who were hospitalized with HF during a prospective national survey. The relationship between ABG and 10-year mortality was assessed using the Cox proportional hazard model adjusting for multiple variables. ABG was analyzed both as a categorical (200 mg/dL) and as a continuous variable. At 10 years of follow-up the cumulative probability of mortality was 85 and 78% among patients with DM and patients with no pre-existing DM (p < 0.001), respectively. Among patients with no pre-existing DM, glucose levels of 110–140, 140–200 and ≥200 mg/dL were associated with 9% (p = 0.140), 16% (p = 0.031) and 53% (p < 0.001) increased mortality risk compared to ABG < 110 mg/dL. Each 18-mg/dL (1-mmol/L) increase in glucose level was associated with a 5% increased risk of mortality (p < 0.001) among patients with no-pre-existing DM. In contrast, among patients with DM, only those with glucose levels >200 mg/dL had an increased mortality risk (>200 mg/dL versus 200 mg/dL is associated with increased mortality risk.

Immune checkpoint inhibitors (ICIs) have transformed cancer treatment, but ICI myocarditis (ICI-M) remains a potentially fatal complication. The clinical implications and predictors of left ventricular ejection fraction (LVEF) <50% in ICI-M are not well understood. The aim of this study was to identify factors associated with LVEF <50% vs ≥50% at the time of hospitalization for ICI-M. A secondary objective was to evaluate the relationship between LVEF and 30-day all-cause mortality. The International ICI-Myocarditis Registry, a retrospective, international, multicenter database, included 757 patients hospitalized with ICI-M. Patients were stratified by LVEF as reduced LVEF (<50%) or preserved LVEF (≥50%) on admission. Cox proportional hazards models were used to assess the associations between LVEF and clinical events, and multivariable logistic regression was conducted to examine factors linked to LVEF. Of 757 patients, 707 had documented LVEFs on admission: 244 (35%) with LVEF <50% and 463 (65%) with LVEF ≥50%. Compared with patients with LVEF ≥50%, those with LVEF <50% were younger (<70 years), had a body mass index of <25 kg/m², and were more likely to have received chest radiation (24.2% vs 13.5%; P < 0.001). Multivariable analysis identified predictors of LVEF <50%, including exposure to v-raf murine sarcoma viral oncogene homolog B1/mitogen-activated protein kinase inhibitors, pre-existing heart failure, dyspnea at presentation, and at least 40 days from ICI initiation to ICI-M onset. Conversely, myositis symptoms were associated with LVEF ≥50%. LVEF <50% was marginally associated with 30-day all-cause mortality (unadjusted log-rank P = 0.062; adjusted for age, cancer types, and ICI therapy, HR: 1.50; 95% CI: 1.02-2.20). Dyspnea, time from ICI initiation, a history of heart failure, and prior cardiotoxic therapy may be predictors of an initial LVEF <50% in patients with ICI-M.