Risk factors of thromboembolism in nonvalvular atrial fibrillation patients with low CHA2DS2-VASc score

Abstract

The risk of thromboembolism in patients with CHA 2 DS 2 -VASc score of 0 to 1 was low, and the anticoagulant therapy was not recommended. Although the CHA 2 DS 2 -VASc score was low, there were still many patients suffered from thrombotic events and stroke. We aim to investigate the risk factors of thrombotic events in nonvalvular atrial fibrillation (NVAF) patients with low CHA 2 DS 2 -VASc score. We retrospectively enrolled 595 consecutive NVAF patients with low CHA 2 DS 2 -VASc score (male: CHA 2 DS 2 -VASc = 0, female: CHA 2 DS 2 -VASc = 1). The general clinical data, blood biochemical data, and echocardiography results of the 595 patients were collected. Multivariate logistic regression models were used to evaluate risk factors of thrombosis. Receiver operating characteristic curve was used to identify the optimal cut-off value of the independent risk factors. A P value of <.05 (2-sided) was considered to be statistically significant. In multivariate analysis, lipoprotein (a) (Lp(a)) plasma level and left atrium diameter (LAD) were positively related to thromboembolism in NVAF patients with CHA 2 DS 2 -VASc score of 0 to 1 after adjustment for age, gender, and other variables (odds ratio [OR] = 1.02, 95% confidence interval [CI]: 1.01–1.03; OR = 1.13, 95% CI: 1.06–1.18). Lp(a) exerted a significant predictive value with area under the curve (AUC) of 0.62 (95% CI: 0.55–0.68, P < .01). The optimal cut-off value for Lp(a) predicting thrombotic events was 27.2 mg/dL (sensitivity 45.7%, specificity 73.4%). LAD showed a significant predictive value with AUC of 0.71 (95% CI: 0.64–0.78, P < .01). The optimal cut-off point for LAD predicting thrombotic events was 43.5 mm (sensitivity 47.1%, specificity 85.8%). High Lp(a) plasma level and left atrial dilatation might be independent risk factors of thrombotic events for NVAF patients with low CHA 2 DS 2 -VASc score.

Relationship between lipoproteins, thrombosis, and atrial fibrillation

“…More recently, higher Lp(a) levels were found to be independently associated with clinically confirmed thromboembolic events in non-valvular AF patients with a CHA 2 DS 2 -VASc score of less than two. 162 Curiously, Aronis et al 54 found that elevated levels of Lp(a) was associated with an increased stroke risk among non-AF patients, but not in those with AF. In support of the latter, we previously demonstrated that there was no correlation between Lp(a) and D-dimer, as a marker of thrombogenesis.…”

Finding low CHA2DS2-VASc scores unreliable? Why not give morphological and hemodynamic methods a try?

“…Left atrial diameter (LAD) was found to have an AUC generally over 0.7 in AF patients, with relatively balanced specificity and sensitivity. One study about low-score patients reported an AUC of 0.878 (cutoff point 43.5 mm, sensitivity 84.4%, specificity 74.7%), and if we bind LAD with CHA2DS2-VASc, we were still able to obtain a much better predictive value (AUC 0.747 vs. 0.541) ( 19 , 31 , 34 , 36 , 51 ). Left atrium top and bottom diameter (LTD) also has a decent value (AUC 0.705, sensitivity 75.7%, specificity 73.7%), which is not as good as LAD.…”

“…In other words, although our review shows that some of the parameters, such as LAD and blood flow velocity-related parameters, have higher AUCs, the conclusion may not be correct. Additionally, although our review mainly focused on thrombosis risk and the endpoint of many studies included may be LA/LAA thrombus, which is the main cause of stroke in AF ( 61 ), doctors may care more about predicting specific thrombosis events, and in our study, only LAA orifice area, LAD, and LAA flow velocity were reported to be used in predicting thromboembolic events like stroke ( 34 , 46 ), so some more direct studies are needed. Moreover, we found that many of the parameters reported above do not have an independent relationship with thrombus risk, and some of them may compensate for each other.…”

“…On the one hand, patients with low CHA2DS2-VASc scores have a considerable rate of LAT. The annual stroke rate was reported to be approximately 3% among men whose score was one and among women whose score was two, while the incidence of thrombotic events even reached 11.4% in patients with AF with CHA2DS2-VASc scores of 0 to 1 ( 33 , 34 ). However, some patients with high scores did not have as high a risk as expected.…”

Association between lipoprotein(a) and thromboembolism in patients with non-valvular atrial fibrillation: a cross-sectional study

“…In this study, we observed that an increased level of Lp(a) was associated with a higher risk of IS in AF patients with CHA 2 DS 2 -VASc < 2 scores, indicating that the residual cardiovascular risk in this population remains high, and clinicians should focus on it. A small-sample case-control study showed that Lp(a) was an independent risk factor for thromboembolism in NVAF patients with a CHA 2 DS 2 -VASc score of 0–1 [ 33 ]. However, they did not report the respective prevalence rates of IS and SEE in thromboembolic events and the results of logistic regression analysis; therefore, it cannot be concluded that Lp(a) is related to IS and SEE in patients with NVAF with low CHA 2 DS 2 -VASc scores.…”