New Study Demonstrates Significant Burden of New Onset Atrial Fibrillation in Patients Undergoing Aortic Valve Replacement

A study led by Dr. Rajat Kalra published in JAMA Internal Medicine showed that new-onset atrial fibrillation is a significant burden on patients after aortic valve replacement either through trans-jugular aortic valve implantation (TAVI) or aortic valve replacement (AVR). Additionally, the investigators demonstrated that atrial fibrillation (AF) was higher after AVR than after TAVI.

Atrial fibrillation is one of the most common arrhythmias with a prevalence of up to 37% in individuals over the age of 55. AF is also associated with significant cardiovascular mortality and morbidity. Additionally, AF has been recognized as a common occurrence after surgery, including aortic valve replacement, with the incidence of AF after TAVI or AVR ranging between 8-100%. However, most studies that assessed the association between aortic valve replacement and new-onset AF were single center or based on analysis of clinical trial data. The investigators aimed to assess the association between aortic valve replacement (either surgically or TAVI) and new-onset AF in a large cohort sample of hospitalizations.

The study population was derived from the NIS (National Inpatient Sample). All hospitalizations with aortic valve stenosis that occurred between January 1, 2012 and September 30, 2015 were identified. Of those patients, all patients who underwent TAVI or surgical AVR were identified. Patients with a prior history of AF or other arrhythmias were excluded and those who had percutaneous coronary intervention or coronary artery bypass grafting done during that same hospitalization. The primary outcome was the incidence of new-onset atrial fibrillation after TAVI and AVR during that hospitalization. All diagnoses and procedures were identified using ICD-9 codes. Additionally, the investigators built a model to assess the association between baseline factors and the occurrence of new-onset AF.

A total of 171,480 hospitalizations were identified. Of those, 48,715 patients underwent TAVI and 122,765 underwent AVR. New-onset atrial fibrillation occurred in 50.4% of TAVI hospitalizations and 50.1% of AVR hospitalizations. Some of the baseline factors associated with new-onset AF included age, white race, chronic kidney disease at baseline, chronic pulmonary disease at baseline, and congestive heart failure at baseline. When assessing mortality, the investigators found that patients with new-onset AF had higher odds of in-hospital mortality (TAVI OR 1.57, 95% CI 1.21-2.04; and AVR OR 1.36, 95% CI 1.08-1.70). Finally, the results of the study were then compared to the New York state inpatient database. The authors found that the incidence of new-onset atrial fibrillation was 14.1% (244 of 1736 hospitalizations) after TAVI and 30.6% (1573 of 5141 hospitalizations) after AVR.

The investigators found that the incidence of new-onset AF after TAVI and AVR is almost 50% in both groups. Additionally, patients who do develop AF end up having a higher in-hospital mortality rate as compared to those who don’t. The incidence of new-onset AF in the study population is higher than that in the New York state inpatient database. The findings of this study have significant implications. Dr. Kalra wrote, “given the medical and socioeconomic burdens that atrial fibrillation and aortic valve disease carry on a population level. Our investigation raises the question of how perioperative anticoagulation strategies must be altered for TAVI and AVR with such a high incidence of post-procedural atrial fibrillation.” Also, considering the findings of the study and increased mortality associated with AF, the authors argue for including AF at baseline and/or new-onset AF in the risk stratification scoring schemes for patients undergoing TAVI.