Results:
Of the 2,020 patients included in this registry, 201 (10.0%) were young. The majority of patients were enrolled in the outpatient setting (72.8%). The baseline characteristics for both groups are summarized in Table 1. There was a lower prevalence of HTN, DM, and dyslipidemia in the young group compared to the older patients (31.3% vs. 79.3%, 10.4% vs. 47.2%, and 23.9% vs. 47.3%, respectively, all with a p-value <0.001). Cigarette smoking was significantly more prevalent in the young group compared to the older group (38.3% vs. 11.2%, P<0.001). Additionally, heart failure (HF), left ventricular ejection fraction (LVEF)<40%, left ventricular hypertrophy (LVH), pulmonary HTN, OSA, chronic kidney disease (CKD), and co-existing thyroid diseases were all significantly higher in the older group.
Paroxysmal AF was the most common initial presentation in both groups, but it was more common in the young group compared to the older group. Valvular AF (AF in a patient with moderate to severe rheumatic mitral stenosis or prosthetic mitral valve) was uncommon in both groups.
Prior stroke (hemorrhagic, embolic, or thrombotic) was more common in the older group. However, a history of previous systemic embolism was rare in both groups.
Symptoms at presentation varied between the two groups (Table 2). Palpitations were more common as a presenting symptom in the young, while fatigue and dyspnea were more common at presentation in the older group.
The mean CHA2DS2VASC score was significantly lower in the younger population, and a higher percentage of patients in the older population had a score of ≥2 (Table 2). Women had higher scores in both populations as shown in Figure 1. The mean HAS-BLED score was significantly higher in the older population (1.81±1.1 vs. 0.6±0.7, p<0.001), as shown in Table 3 and Figure 2.
In patients with valvular AF (VAF), OACs were used by most patients in both groups, with vitamin K antagonists (VKAs) being the mainstay of therapy. In patients with non-valvular AF (NVAF), the rate of utilization of OAC therapy varied according to the CHA2DS2-VASc risk category and was higher in the older population in all risk categories. Overall, 44.3% of the younger population with NVAF were not taking any anticoagulant therapy compared to 14.9% of the older population.
There were 28 (13.9%) and 1479 (81.3%) young and older patients with a high CHA2DS2-VASc score (≥3 in females and ≥2 in males), respectively. Of those, 75% of the young and 83.2% of the older group were prescribed OACs (p<0.001). DOACs were prescribed more frequently than VKA in the young (53.6% vs. 21.4%) and in the older patients (53.1% vs. 30.1%). OACs which are typically not indicated for patients with low risk CHA2DS2-VASc scores, were prescribed in 27.2% of young and in 49% of older patients.
At 1 year from enrollment, 116 patients were lost to follow-up: 14 from the young age group and 102 from the older age group. Follow-up data were available for 1904 patients. All-cause mortality rate was 1.1% of the young group and 13.7% in the older group (p=0.001). Cardiovascular death was less frequent in the younger group (1.1% vs 7.7%, P=0.04), and so was major bleeding (0% vs 2.7%, P=0.02). However, there was no significant difference between the two age groups in the incidence of stroke or systemic embolism (3.4% vs 4.4%) (Figure 3).