Association of Thoracic Aorta Calcium Score With Left Ventricular Hypertrophy and Clinical Outcomes in Patients With Severe Aortic Stenosis After Aortic Valve Replacement

Abstract

BACKGROUND: Substantial aortic calcification is known to be associated with aortic stiffening and subsequent left ventricular (LV) hypertrophy. This study examined whether the thoracic aorta calcium score (TACS) is related to LV hypertrophy and whether it leads to an adverse prognosis in patients with severe aortic stenosis (AS) after aortic valve replacement (AVR).

METHODS: We retrospectively reviewed 47 patients (mean age, 64 ± 11 years) with isolated severe AS who underwent noncontrast computed tomography of the entire thoracic aorta and who received AVR. TACS was quantified using the volume method with values becoming log transformed (log[TACS+1]). Transthoracic echocardiography was performed before and 1 year after the operation.

RESULTS: Preoperative LV mass index (LVMI) displayed significant positive correlations with male gender (r = 0.430, p = 0.010) and log(TACS+1) (r = 0.556, p = 0.003). In multivariate linear regression analysis, only log(TACS+1) was independently associated with LVMI, even after adjusting for age, gender, transaortic mean pressure gradient, and coronary or valve calcium score. Independent determinants for postoperative LVMI included log(TACS+1) and preoperative LVMI after 1 year of follow-up echocardiography, adjusting for age, gender, indexed effective orifice area, and coronary or valve calcium score. During a median follow-up period of 54 months after AVR, there were 10 events (21%), which included 4 deaths from all-causes, 3 strokes, 2 inpatient admissions for heart failure, and 1 myocardial infarction. The event-free survival rate was significantly lower for patients with TACS of 2,257 mm3 or higher compared with those whose TACS was lower than 2,257 mm3 (log-rank p < 0.001).

CONCLUSIONS: High TACS was associated with increased LVMI among patients with severe AS. Further, high TACS usefully predicted less regression of LVMI and poor clinical outcomes after AVR. TACS may serve as a useful proxy for predicting LV remodeling and adverse prognosis in patients with severe AS undergoing AVR.