Cardiovascular safety of a standardized outpatient triage and diagnostic approach for suspected cardiovascular immune-related adverse events of immune checkpoint inhibitors.

Background: Immune checkpoint inhibitors have changed cancer prognosis, at the expense of potential cardiovascular immune-related adverse events. Guidelines recommend troponin testing, prompting hospital admission if abnormal.

Aim: To assess the safety of outpatient management of suspected cardiovascular immune-related adverse events.

Methods: This is a prospective cohort study of all consecutive adults referred for suspected cardiovascular immune-related adverse events. Hospital admission followed a prespecified algorithm. In the absence of cardiovascular or muscle symptoms, double immune checkpoint inhibitors, electrocardiogram changes, and cardiovascular or immune disease, patients were managed as outpatients. The primary objective was safety of outpatient management, with cardiovascular death at 30days as the main outcome; the secondary objective was identification of factors associated with cardiovascular immune-related adverse events at referral.

Results: Among the 175 patients enrolled between March 2022 and October 2023, 135 (72.11%) were female, the median age was 61 (interquartile range 48.0; 72.0) years, 146 (83.43%) were outpatients and 112 (64.00%) were referred for asymptomatic troponin increase. There were no cardiovascular deaths at 30days. Ninety-five (54.29%) patients had cardiovascular immune-related adverse events at referral, among whom 72 (41.14%) were diagnosed with immune checkpoint inhibitor-related myocarditis. History of cardiovascular disease (odds ratio 2.52, 95% confidence interval 1.12-5.40; P=0.017) and global longitudinal strain <16% (odds ratio 2.18, 95% confidence interval 1.03-4.63; P=0.042) were independently associated with cardiovascular immune-related adverse events at referral.

Conclusions: Outpatient management is feasible in most patients when cardiovascular immune-related adverse events are suspected, provided that a FAST TRACK immune checkpoint inhibitor safety checklist is applied by the oncologists for triage. History of cardiovascular disease and global longitudinal strain are associated with the diagnosis of cardiovascular immune-related adverse events.