Composite risk scores and composite endpoints in the risk prediction of outcomes in anticoagulated patients with atrial fibrillation. The Loire Valley Atrial Fibrillation Project.

Several validated risk stratification schemes for prediction of ischaemic stroke (IS)/thromboembolism (TE) and major bleeding are available for patients with non-valvular atrial fibrillation (NVAF). On the basis for multiple common risk factors for IS/TE and bleeding, it has been suggested that composite risk prediction scores may be more practical and user-friendly than separate scores for bleeding and IS/TE. In a long-term prospective hospital registry of anticoagulated patients with newly diagnosed AF, we compared the predictive value of existing risk prediction scores as well as composite risk scores, and also compared these risk scoring systems using composite endpoints. Endpoint 1 was the simple composite of IS and major bleeds. Endpoint 2 was based on a composite of IS plus intracerebral haemorrhage (ICH). Endpoint 3 was based on weighted coefficients for IS/TE and ICH. Endpoint 4 was a composite of stroke, cardiovascular death, TE and major bleeding. The incremental predictive value of these scores over CHADS2 (as reference) for composite endpoints was assessed using c-statistic, net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Of 8,962 eligible individuals, 3,607 (40.2%) had NVAF and were on OAC at baseline. There were no statistically significant differences between the c-statistics of the various risk scores, compared with the CHADS2 score, regardless of the endpoint. For the various risk scores and various endpoints, NRI and IDI did not show significant improvement (≥1%), compared with the CHADS2 score. In conclusion, composite risk scores did not significantly improve risk prediction of endpoints in patients with NVAF, regardless of how endpoints were defined. This would support individualised prediction of IS/TE and bleeding separately using different separate risk prediction tools, and not the use of composite scores or endpoints for everyday 'real world' clinical practice, to guide decisions on thromboprophylaxis.

Anticoagulation in patients with atrial fibrillation undergoing coronary stent implantation.

In patients with atrial fibrillation (AF) undergoing coronary stent implantation, the optimal antithrombotic strategy is unclear. We evaluated whether use of oral anticoagulation (OAC) was associated with any benefit in morbidity or mortality in patients with AF, high risk of thromboembolism (TE) (CHA2DS2-VASC score ≥ 2) and coronary stent implantation. Among 8,962 unselected patients with AF seen between 2000 and 2010, a total of 2,709 (30%) had coronary artery disease and 417/2,709 (15%) underwent stent implantation while having CHA2DS2-VASC score ≥ 2. During follow-up (median=650 days), all TE, bleeding episodes, and major adverse cardiac events (i.e. death, acute myocardial infarction, target lesion revascularisation) were recorded. At discharge, 97/417 patients (23%) received OAC, which was more likely to be prescribed in patients with permanent AF and in those treated for elective stent implantation. The incidence of outcome event rates was not significantly different in patients treated and those not treated with OAC. However, in multivariate analysis, the lack of OAC at discharge was independently associated with increased risk of death/stroke/systemic TE (relative risk [RR] =2.18, 95% confidence interval [CI] 1.02-4.67, p=0.04), with older age (RR =1.12, 1.04-1.20, p=0.003), heart failure (RR =3.26, 1.18-9.01, p=0.02), and history of stroke (RR =18.87, 3.11-111.11, p=0.001). In conclusion, in patients with AF and high thromboembolic risk after stent implantation, use of OAC was independently associated with decreased risk of subsequent death/stroke/systemic TE, suggesting that OAC should be systematically used in this patient population.

[Non-antiarrhythmic drug therapy for the prevention of atrial fibrillation?]. / Des médicaments non anti-arythmiques peuvent-ils avoir un effet préventif sur la fibrillation auriculaire?

In atrial fibrillation (AF), the absence of a clear benefit of a rhythm-control strategy over a rate-control strategy seen in recent trials may be due to the fact that many of the usual antiarrhythmic strategy have significant weaknesses. Besides research efforts to improve the efficacy and safety of conventional antiarrhythmic agents, therapies directed 'upstream'of the electrical aspects of AF, towards the underlying anatomical substrate and atrial remodelling, have been proposed as new pharmacological therapeutic approaches. Potential upstream therapies for AF comprise a variety of agents such as angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB), statins, N-3 polyunsaturated fatty acids and steroids. On the basis of experimental data, clinical studies have provided information on the potential of upstream therapy for the prevention of AF across a broad spectrum of cardiovascular patient groups. In patients with heart failure or hypertension, data are sufficient to support the use of ACEI or ARB as treatment that may decrease the risk of AF beyond their other beneficial effects. Similarly, it is highly possible that the use of statin in patients with a recognized indication may be associated with a benefit against AF. However, in most clinical settings, the evidence appears to be insufficient to drive changes in therapy management per se, and large-scale, randomized controlled trials with adequately defined endpoints are still needed. The results from these trials may help to understand the complex mechanisms that lead to AF, and may clarify the benefit-to-risk ratio of these new therapeutic approaches.