Stroke and bleeding risk scores in patients with atrial fibrillation and valvular heart disease: evaluating 'valvular heart disease' in a nationwide cohort study.

Abstract

Substantial interest has been directed towards stroke risk stratification in patients with atrial fibrillation (AF) but prior studies have focused on AF without significant valvular heart disease (VHD), so-called 'non-valvular AF'. A formal validation exercise addressing stroke risks in relation to the CHA2DS2-VASc risk factor(s) in AF patients with VHD is lacking. Also, the use of the HAS-BLED score in anticoagulated patients with VHD has not been previously studied. The aim of this study was to investigate stroke and bleeding rates in AF patients with VHD in relation to the CHA2DS2-VASc and HAS-BLED scores. We conducted a nationwide cohort study. VHD were categorized based on the 2017 joint European consensus document definition, i.e. Evaluated Heartvalves, Rheumatic or Artificial (EHRA) categorization, as follows: (i) EHRA Type 1 VHD, which refers to AF patients with 'VHD needing therapy with a Vitamin K antagonist (VKA)', thus including severe native mitral stenosis and prosthetic mechanical heart valves and (ii) EHRA Type 2 VHD, which refers to AF patients with 'VHD needing therapy with a VKA or a non-VKA oral anticoagulant (NOAC)', thus including all other forms of VHD. We identified 25818 AF patients with VHD with EHRA Type 2 in 90% (n = 23253). Thromboembolism and bleeding events increased with increasing CHA2DS2-VASc and HAS-BLED scores, whether with 1 or 2.5 years follow-up. EHRA Type 1 outcomes: The predictive value of CHA2DS2-VASc score for thromboembolism was modest, c-indexes 0.62 (0.55-0.70) at 1 year. The predictive value of the HAS-BLED score for bleeding was also modest being 0.59 (0.53-0.65) at 1 year. EHRA Type 2 outcomes: The predictive value of CHA2DS2-VASc score for thromboembolism was modest, c-indexes 0.63 (0.60-0.65) at 1 year. The predictive value of the HAS-BLED score for bleeding was also modest being 0.59 (0.53-0.65) at 1 year. This is the first validation of CHA2DS2-VASc and HAS-BLED scores in AF patients with VHD (so-called 'valvular AF') using the new EHRA classification. Both scores are modestly predictive of thromboembolism and bleeding events in VHD, respectively. Event rates increased with increasing risk factors as evident by increasing CHA2DS2-VASc and HAS-BLED score points, consistent with performance of these clinical scores in 'non-valvular AF' patients.