Clinical Outcomes in Hospitalized Patients with Cancer and New versus Preexistent Atrial Fibrillation.

Background: There is limited information on the prognostic impact of new onset versus preexistent atrial fibrillation (AF) in hospitalized patients with cancer.

Objectives: We sought to determine the clinical impact of new onset AF (NOAF) compared with preexistent AF in hospitalized patients with cancer.

Methods: All patients with cancer hospitalized over the course of 1 year with clinically manifest new or preexistent AF were enrolled in the Memorial Sloan Kettering Cancer Center AF registry. The relationship of NOAF to the primary composite outcome of all cause death, cardiovascular (CV) rehospitalization, or cerebrovascular event (CVE), as well as secondary CV endpoints, were analysed using proportional hazards regression. Where applicable, the competing risk of death was accounted for using methodology described by Fine and Gray.

Results: Among 606 patients included in the analysis, 313 (51.7%) had NOAF and 293 (48.3%) had preexistent AF. Patients with NOAF were younger and had less frequent prior history of CV disease compared with patients with preexistent AF. At follow-up, patients with NOAF had a higher adjusted hazard for the primary composite outcome versus patients with prior AF (hazard ratio [HR] 1.64, 95% confidence interval [CI] 1.27, 2.13, P = 0.002), as well as the secondary CV composite outcome of clinical AF recurrence, CV death, CV rehospitalization, or CVE (HR 2.17, 95% CI 1.57, 2.99, P < 0.0001).

Conclusions: In hospitalized patients with cancer and electrocardiographically manifest new versus preexistent AF, NOAF was associated with a higher risk for the primary composite outcome of all-cause death, CV rehospitalization, or CVE.