Prognosis and antithrombotic practice patterns in recurrent and transient atrial fibrillation following acute coronary syndrome: a nationwide study

Background

First-time detected atrial fibrillation (AF) during acute coronary syndrome (ACS) aggravates the prognosis and increases the risk of ischemic stroke. In this setting, AF may present as brief and transient or with recurrent episodes after discharge. However, data on the association between transient or recurrent AF and ischemic stroke in patients with ACS are sparse. Further, despite being associated with ischemic stroke, first-time detected AF patients have been reported with low oral anticoagulation (OAC) rates.

Purpose

To examine the associated rate of ischemic stroke and mortality in ACS survivors with transient or recurrent AF and to assess the antithrombotic practice patterns one year after ACS.

Methods

Using data from Danish nationwide registries, we identified all patients with first-time ACS, without known AF prior to ACS, from 2000–2017 who were alive one year after ACS discharge (index date). According to a grace period between ACS discharge and one year after ACS discharge, patients were categorized into: i) no AF; ii) first-time detected AF during ACS admission without AF recurrence (transient AF); and iii) first-time detected AF during ACS admission with a subsequent recurrent AF episode (recurrent AF). Patients who developed AF during the grace period were excluded. Patients were followed from one year post ACS discharge, and two-year rates of ischemic stroke and mortality were compared using multivariable adjusted Cox proportional hazards analysis. Further, we assessed the prescribed OAC rates in a three-month period following the index date.

Results

We included 116,793 patients surviving one year post ACS discharge: 111,708 (95.6%) without AF (64.9% male, median age 64 years), 2,671 (2.3%) with transient AF (58.0% male, median age 74 years), and 2,414 (2.1%) with recurrent AF (55.2% male, median age 76 years). The cumulative two-year incidence of ischemic stroke was 0.9%, 1.5%, and 2.3% for patients without AF, transient AF, and recurrent AF, respectively (Figure 1). The cumulative two-year incidence of mortality was 7.4%, 12.1%, and 20.3% for patients without AF, transient AF, and recurrent AF, respectively (Figure 1). Compared to those without AF, the adjusted two-year rates of outcomes were as follows: ischemic stroke: HR 1.15 (95% CI: 0.81–1.61) for patients with transient AF and HR 1.50 (95% CI: 1.14–1.98) for patients with recurrent AF; mortality: HR 0.98 (95% CI: 0.87–1.10) for patients with transient AF and HR 1.35 (95% CI: 1.23–1.49) for patients with recurrent AF (Figure). We identified that 20.9% for transient AF and 42.2% for recurrent AF were prescribed OAC therapy in the three-month period after one year.

Conclusion

In patients surviving one year after ACS with first-time detected AF, a recurrent AF episode was associated with an increased long-term rate of ischemic stroke and mortality, while transient AF yielded no statistically difference as compared with patients without AF.

Funding Acknowledgement

Type of funding sources: None.

P3798High levels of C-reactive protein after coronary artery bypass graft surgery is associated with postoperative atrial fibrillation

Background

Postoperative atrial fibrillation (POAF), a common complication following coronary artery bypass graft (CABG) surgery, is associated with increased morbidity and mortality. Inflammation seems to be an important pathogenic factor and elevated preoperative levels of C-reactive protein (CRP) are associated with POAF. However, the association between postoperative CRP and POAF is less established.

Purpose

To examine the association between postoperative levels of CRP and POAF after CABG.

Methods

Patients undergoing first-time isolated CABG (Jan 01, 2000 to Dec 31, 2016) were identified using Danish nationwide administrative registries. Patients with CRP measurements from the fourth postoperative day and no history of atrial fibrillation were included. POAF was defined as a postoperative atrial fibrillation rhythm that required medical therapy or cardioversion, with patients being followed for POAF until discharge. The study population was divided into quartiles based on CRP levels. A Cochran-Armitage trend test was used to examine the trend of increased levels of CRP and the associated risk of POAF. The association between CRP levels and POAF was investigated using a multivariable logistic regression analysis adjusted for other patient characteristics.

Results

The study included 6,711 patients with mean CRP values from the lowest to the highest CRP groups being 66, 109, 150 and 228 mg/L, respectively. Patients in the highest CRP group were older and more likely to be male compared with the lowest CRP group (median age 67 years [P25-P75: 61–73] and 84.7% men vs. median age 64 years [P25-P75: 56–70] and 77.9% men). In the highest CRP group, 35% of patients developed POAF vs. 25% in the lowest CRP group. A dose-response relationship was seen between increasing levels of CRP and the associated risk of POAF (p<0.0001 for trend). An adjusted analysis showed a statistically significant association between the highest CPR group and POAF (OR: 1.44; 95% CI: 1.24–1.69) compared with the lowest CRP group (figure 1).

Conclusion

High postoperative CRP levels after CABG were associated with POAF development. Future studies may examine whether CRP also predicts worse outcomes and whether these factors could be modified in the development of POAF.

Acknowledgement/Funding

Internal grant from Copenhagen University Hospital