Thromboembolic Risk of Imaging-Confirmed Coronary Artery Disease Without Myocardial Infarction in Patients With Nonvalvular Atrial Fibrillation

High incidence of newly diagnosed obstructive coronary artery disease regardless of chest pain detected on pre-procedural cardiac computed tomography angiography in patients undergoing atrial fibrillation ablation

BACKGROUND

Cardiac computed tomography (CT) is often performed before catheter ablation of atrial fibrillation to map atrial and pulmonary anatomy. Incident coronary artery disease (CAD) may also be diagnosed during cardiac CT angiography (CTA). Our aim was to assess whether coronary CTA might be able to identify a significant proportion of patients with obstructive CAD prior to their catheter ablation procedure event, even in asymptomatic patients.

METHODS

Consecutive patients undergoing pre-ablation coronary CTA for atrial fibrillation between 2013 and 2020 were retrospectively selected. Patients with previously diagnosed CAD were excluded. Obstructive CAD was defined as ≥50% luminal stenosis. We analyzed the relationship between obstructive CAD, any chest pain, and traditional risk factors.

RESULTS

Overall, 2321 patients [median age 63.0 (54.4-69.2), 1052/2321 (45.3%) female] underwent coronary CTA and 488/2321 (21.0%) were diagnosed with obstructive CAD. There was no difference regarding the rate of obstructive CAD in patients with any chest pain compared to patients without any chest pain [91/404 (22.5%) vs. 397/1917 (20.7%), P = 0.416, respectively). The following parameters were associated with obstructive CAD: age > 65 years [odds ratio (OR) = 2.51; 95% confidence interval (CI), 2.02-3.13; P < 0.001), male sex (OR = 1.59; 95% CI, 1.28-1.98; P < 0.001), hypertension (OR = 1.40; 95% CI, 1.08-1.81; P = 0.012), diabetes (OR = 1.50; 95% CI, 1.13-1.99; P = 0.006), dyslipidaemia (OR = 1.33; 95% CI, 1.07-1.66; P = 0.011) and history of smoking (OR = 1.34; 95% CI, 1.07-1.68; P = 0.011).

CONCLUSIONS

The high prevalence of obstructive CAD even in patients without chest pain highlights the importance of additional coronary artery diagnostics in patients undergoing left atrial CTA awaiting catheter ablation for atrial fibrillation. These patients regardless of chest pain thus may require further risk modification to decrease their potential ischemic and thromboembolic risk.

Outcome of catheter ablation for paroxysmal atrial fibrillation in patients with stable coronary artery disease

BACKGROUND

Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. This study aimed to assess the long-term outcome of catheter ablation in patients with paroxysmal AF and SCAD.

METHODS

In total, 12104 patients with paroxysmal AF underwent catheter ablation in the Chinese Atrial Fibrillation Registry between 2011 and 2019 were screened. A total of 441 patients with SCAD were matched with patients without SCAD in a 1:4 ratio. The primary endpoint was AF recurrence after single ablation. The composite secondary endpoints were thromboembolism, coronary events, major bleeding, all-cause death. RESULTS;: Over a mean follow-up of 46.0±18.9 months, the recurrence rate in patients with SCAD was significantly higher after a single ablation (49.0% vs. 41.9%, P = 0.03). The very late recurrence rate of AF in the SCAD group was also significantly higher than that in the control group (38.9% vs. 31.2%;P = 0.04). In multivariate analysis, adjusted with the female, smoking, duration of AF, previous thromboembolism, COPD, and statins, SCAD was independently associated with AF recurrence (adjusted HR, 1.19 [1.02-1.40], P = 0.03). The composite secondary endpoints were significantly higher in the SCAD group (12.70% vs. 8.54%, P = 0.02), mainly due to thromboembolism events (8.16% vs. 4.41%, P<0.01).

CONCLUSIONS

SCAD significantly increased the risk of recurrence after catheter ablation of paroxysmal AF. The incidence of thromboembolic events after catheter ablation of paroxysmal AF in the patients with SCAD was significantly higher than that in those without SCAD. This article is protected by copyright. All rights reserved.

Edoxaban-based long-term antithrombotic therapy in patients with atrial fibrillation and stable coronary disease: Rationale and design of the randomized EPIC-CAD trial

BACKGROUND

Anticoagulants are the standard therapy for patients with atrial fibrillation (AF) and antiplatelet therapy for those with coronary artery disease (CAD). However, compelling clinical evidence is still lacking regarding the long-term maintenance strategy with the combination of anticoagulant and antiplatelet drugs in patients with AF and stable CAD.

DESIGN

The EPIC-CAD trial is an investigator-initiated, multicenter, open-label randomized trial comparing the safety and efficacy of 2 antithrombotic strategies in patients with high-risk AF (CHA₂DS₂-VASc score ≥ 2 points) and stable CAD (≥6 months after revascularization for stable angina or ≥12 months for acute coronary syndrome; or medical therapy alone). Patients (approximately N = 1,038) will be randomly assigned at a 1:1 ratio to (1) monotherapy with edoxaban (a non-vitamin K antagonist oral anticoagulant) or (2) combination therapy with edoxaban plus a single antiplatelet agent. The primary endpoint is the net composite outcome of death from any cause, stroke, systemic embolism, myocardial infarction, unplanned revascularization, and major or clinically relevant nonmajor bleeding at 1 year after randomization.

RESULTS

As of December 2021, approximately 901 patients had been randomly enrolled over 2 years at 18 major cardiac centers across South Korea. The completed enrollment is expected at the mid-term of 2022, and the primary results will be available by 2023.

CONCLUSIONS

EPIC-CAD is a large-scale, multicenter, pragmatic design trial, which will provide valuable clinical insight into edoxaban-based long-term antithrombotic therapy in patients with high-risk AF and stable CAD.

Relation of Left Atrial Enlargement to Subsequent Thromboembolic Events in Nonvalvular Atrial Fibrillation Patients With Low to Borderline Embolic Risk

The current thromboembolic risk stratification of non-valvular atrial fibrillation (NVAF) does not include parameters from transthoracic echocardiography (TTE). We hypothesized that left atrial enlargement (LAE) on TTE could discriminate who require anticoagulation therapy among NVAF patients with low/borderline clinical embolic risk. This single-center cohort study included 6,602 patients with NVAF (median age, 56 years, 70.0% male) with a low to borderline clinical embolic risk (CHA₂DS₂-VASc score: 0 to 1 in males, 1 to 2 in females). LAE was classified as mild (≥41 mm in males; ≥39 mm in females) or moderate-severe (≥47 mm in males; ≥43 mm in females). The main study outcome was thromboembolic event (ischemic stroke and systemic embolism). Mild and moderate-severe LAE was diagnosed in 26.1% and 32.9% of the cohort, respectively. The patients with moderate-severe LAE showed a higher prevalence of baseline comorbidities and valvular heart disease and had a higher incidence of thromboembolic events than patients with mild or no LAE at 2 years of follow-up (2.5% vs 1.3% vs 1.1%, respectively, p < 0.001). After multivariable adjustment, patients with moderate-severe LAE were at a higher risk of thromboembolic event (hazard ratio, 2.54; 95% CI, 1.65 to 3.90; p < 0.001) compared to those with no LAE. This result persisted in a subgroup analysis of anticoagulant-naïve patients. The rate of thromboembolic events in patients with low clinical embolic risk and moderate-severe LAE was not different to those with high clinical embolic risk without LAE. In conclusion, Moderate-severe LAE on TTE was a significant predictor of thromboembolic events in NVAF patients at low/borderline clinical embolic risk.

Risk of Myocardial Infarction in Patients Without Angiographic Coronary Artery Disease Compared With the General Population

We examined the 10-year risk of myocardial infarction (MI) and death in patients without obstructive coronary artery disease (CAD) compared with the general population. We conducted a cohort study of every patient without obstructive CAD by coronary angiography (CAG) between 2003 and 2016 in Western Denmark. Patients were matched by gender and age with individuals from the general population of Western Denmark with no history of CAD. End points were MI and death. Ten-year risk differences in cumulative incidence proportions were computed, accounting for the competing risk of death in the case of MI. Unadjusted and adjusted incidence rate ratios (aIRRs) were estimated using conditional Poisson regression. We included 46,467 patients and 234,654 individuals from the general population. Median follow-up was 7.7 years. The 10-year cumulative incidence of MI was 2.40% (95% confidence interval [CI] 2.24 to 2.57) in patients without obstructive CAD in the CAG and 2.70% (95% CI 2.62 to 2.78) in the general population, with a reduced absolute 10-year risk (risk difference -0.30%, 95% CI -0.49 to -0.12) and a reduced aIRR (aIRR 0.70, 95% CI 0.63 to 0.77). Ten-year mortality was higher in patients without obstructive CAD in the CAG (21.44%, 95% CI 20.99 to 21.89) compared with the general population (17.25%, 95% CI 17.06 to 17.44). However, mortality rates were similar after adjustment (aIRR 1.00, 95% CI 0.96 to 1.02). In conclusion, the absence of obstructive CAD according to CAG is associated with a lower risk of MI than in the general population, and similar 10-year mortality.

Prognostic Value of Subclinical Coronary Artery Disease in Atrial Fibrillation Patients Identified by Coronary Computed Tomography Angiography

Identifying coronary artery disease (CAD) in atrial fibrillation (AF) patients improves risk stratification and defines clinical management. However, the value of screening for subclinical CAD with cardiac CT in AF patients is unknown. Between 2011 and 2015, 94 consecutive patients without known or suspected CAD (66 (57-73) years, 68% male), who were referred for AF evaluation, underwent a noncontrast-enhanced coronary calcium scan and a coronary computed tomography angiography (CCTA) at our center. We retrospectively evaluated the coronary calcium score, the prevalence of obstructive CAD (≥50% stenosis) determined by CCTA, compared clinical management and 5-year outcome in patients with and without obstructive CAD on CCTA, and examined the potential impact of a coronary calcium score and obstructive CAD on CCTA as a manifestation of vascular disease on the CHA2Ds2VASc score and for the cardiovascular risk stratification of AF patients. The median coronary calcium score was 57 (0-275) and 24 patients (26%) had obstructive CAD on CCTA. At baseline, patients with obstructive CAD more often used statins than those without obstructive CAD (54% vs 26%, p = 0.011). After a median clinical follow-up of 2.4 (0.5-4.5) years, patients with obstructive CAD more frequently used oral anticoagulant and/or antiplatelet drugs, statins, angiotensin-II-receptor blockers and/or angiotensin-converting-enzyme inhibitors, and less often used class I antiarrhythmic drugs than patients without obstructive CAD (all p <0.050). After a median follow-up of 5.7 (4.8-6.8) years, mortality was higher in patients with obstructive CAD than in those without obstructive CAD (29% vs 11%, log-rank test: p = 0.034). Implementation of a coronary calcium score and/or obstructive CAD on CCTA elevated the CHA2Ds2VASc score and cardiovascular risk stratification in 42 patients (p <0.001) and 47 patients (p = 0.006), respectively. In conclusion, we observed a high prevalence of obstructive CAD on CCTA in AF patients without known or suspected CAD. AF patients with obstructive CAD were managed differently and had a worse prognosis than those without obstructive CAD. Cardiac CT could enhance cardiovascular risk stratification of AF patients.