Cancer and atrial fibrillation/flutter: an analysis of patients referred to electrical cardioversion

Abstract

Abstract Introduction Cancer is associated with an increased risk of atrial fibrillation (AF) development. Both an active tumour and AF are related to increased thromboembolic risk. Purpose To determine the clinical characteristics, management and prognosis of cancer patients with AF or atrial flutter (AFL) referred to electrical cardioversion (EC). Methods We conducted a retrospective study encompassing patients referred to EC due to AF/ AFL in our Cardiology Department, from September 2011 to September 2020. Clinical characteristics, echocardiographic studies and follow-up data were analysed. We considered patients with a recent (up to 5 years) diagnosis of cancer. Primary endpoints were the occurrence of stroke, bleeding complications and all-cause mortality. Results A total of 691 patients were included, with a median age of 67 years-old and 70,8% male predominance. AFL was identified in 21,1% of patients and 57,4% had arterial hypertension. Persistent AF/AFL was diagnosed in 60,7%, 20,4% presented with first diagnosed AF/AFL and 17,9% had paroxysmal episodes. 89,5% of patients had indication for anticoagulation therapy and, of these, 75,4% were medicated with non-vitamin K antagonist oral anticoagulants (NOAC). 58 patients (8,4%) had a recent diagnosis of cancer, who were older (69,7 vs 67,9 years-old; p<0,001) and more frequently cardioverted in an outpatient setting (63,8%). They had a lower rate of heart failure (1,9% vs 16,7%; p=0,004), but a higher prevalence of sleep apnea (13% vs 5,4%; p=0,025) and chronic kidney disease (10,9% vs 4,2%; p=0,027). HAS-BLED score was applied, and higher values were obtained in cancer patients (1,0 vs 0,7; p=0,002). CHA2DS2-VASc score was not significantly different between both groups. NOAC were preferred in cancer patients (86,8% vs 74,2%; p=0,043), instead of vitamin K antagonists. These patients were less referred to AF/AFL ablation procedures (1,9% vs 11,6%; p=0,027). During a median follow-up of 1342 days, no significant differences were found regarding the occurrence of ischemic stroke and bleeding complications. All-cause mortality was significantly higher in cancer patients (31,5% vs 15,5%; p=0,003), but none died from cardiovascular causes. Conclusion Cancer is frequent in patients with AF/AFL referred to EC, who are older and had a higher bleeding risk. Stroke rate was not significantly different than other patients, and NOAC seem to be a safe medication in this population. All-cause mortality is high in cancer patients, but we did not find any association with cardiovascular causes. Funding Acknowledgement Type of funding sources: None.