106 Mitral annulus calcification: potential indicator of vascular disease and higher thromboembolic risk

Abstract Background In CHA2DS2-VASc thromboembolic risk score, vascular diseases (V) include either prior myocardial infarction, peripheral arterial disease or aortic plaque, summarizing the patient’s atherosclerotic burden. Despite this, thromboembolic risk scores used in atrial fibrillation (AF) patients do not include mitral annular calcification (MAC) as a potential indicator of vascular disease. Purpose This case-control study retrospectively assessed the relationship between MAC and thromboembolic risk scores (CHADS2 and CHA2DS2-VASc) in non-valvular AF patients (paroxysmal and non-paroxysmal). Methods We compared thromboembolic risk scores value, clinical and transthoracic echocardiographic data in AF patients with and without MAC. The presence and severity of MAC was assessed in parasternal short axis and apical four chamber views. It was qualitatively defined as either mild, moderate or severe based on echodensity and extension in mitral annulus ring. MAC of > 4mm thickness was also considered severe. Results We included 103 patients: mean age 72.6 ± 9.9 years, 44.7% male, 83.5% hypertensive, 30.1% diabetic, 79.6% with heart failure, 40.8% were in atrial fibrillation and 7.8% had a history of stroke/transient ischemic stroke. We identified MAC in 50.5% patients: 15.7% severe, 50.3% moderate, 34% mild. Mean CHADS2 and CHA2DS2-VASc were 2,56 ± 1.213 and 4.57 ± 1.61, respectively. In MAC patients, both scores tended to increase with a mean of 2,88 ± 1,114, p = 0.003 and 5,211 ± 1,51, p < 0.001 as compared with control (2,23 ± 1,06 and 3,92 ± 1,46), respectively. The presence of MAC was a risk factor for vascular disease (OR = 2,47, χ2 = 34,32, p < 0,001). Moreover, the AUC for CHA2DS2-VASc, CHADS2, and MAC was 0.73 (95% CI, 0.63-0.82) and 0.65 (95% CI, 0.54-0.75), respectively. Both scores showed higher AUC in women: 0.79 (95% CI, 0.67-0.91) for CHA2DS2-VASc and 0.68 (95% CI, 0.54-0.82) for CHADS2. Left ventricular ejection fraction (LVEF) negatively correlated with the presence of MAC (r=-0.254, p = 0.01). Sinus rhythm patients with MAC showed significantly decreased LVEF as compared to those without MAC (55.73 ± 12.3% vs 46.96 ± 14.5 %, p = 0.013). The difference was not significant in AF patients (46.83 ± 10.6% vs 45.92 ± 11.59, p= 0.79). Conclusion The presence of MAC, irrespective of severity, correlates very well with both vascular disease and thromboembolic risk scores. Therefore, we consider that MAC might be a potential indicator of vascular disease and of higher thromboembolic risk. This study raises the question whether inclusion of MAC in thromboembolic risk scores as an indicator of vascular disease (V) might increase their predictive value.