Predictor of left ventricular dysfunction after aortic valve replacement in mixed aortic valve disease.

BACKGROUND

The fate of the left ventricle (LV) after aortic valve replacement (AVR) in mixed aortic valve disease (MAVD) is unknown.

METHODS

Patients with moderate-severe MAVD, ejection fraction ≥50%, and no coronary artery disease who underwent AVR were identified. Moderate-severe MAVD was defined as a combination of ≥moderate aortic stenosis and ≥moderate aortic regurgitation. Assessment for LVD was performed at 1 and 5years after AVR. The purpose of the study was to determine prevalence and predictors of early and late left ventricular dysfunction (LVD) defined as ejection fraction <50% at 1 and 5years post-AVR. The severity of LV hypertrophy was assessed using LV mass index (LVMI), while relative wall thickness (RWT) was used to determine the type of hypertrophy. RWT was calculated as (2×posterior wall thickness)/LV end-diastolic dimension (LVEDD). A RWT score ≥0.42 and <0.42 indicates concentric and eccentric hypertrophy respectively.

RESULTS

Patients with MAVD (n=179); age 63±8years, males 134 (75%); underwent AVR at Mayo Clinic, 1994-2010. Early LVD occurred in 38(21%). Predictors of early LVD were LVMI/LVEDD >3.1 (HR 1.83, CI 1.59-1.98); RWT >0.46 (HR 2.16, CI 1.21-4.99); and older age (HR 1.62, CI 1.23-3.02). Assessment of LV function was performed in 124 patients at 5-years post-AVR, and late LVD was present in 29(23%). Predictors of late LVD were LVMI/LVEDD >3.1 (HR 1.77, CI 1.24-2.01) and RWT >0.46 (HR 1.65, CI 1.29-2.24). All-cause mortality occurred in 21(12%), and was more common in patients with LVMI/LVEDD >3.1 (P=0.043) and RWT >0.46 (P=0.029). Patients with postoperative LVD showed less regression of LV mass after AVR even after controlling for blood pressure.

CONCLUSIONS

LVD can occur after AVR even in the setting of normal preoperative LV function and absence of coronary artery disease. Preoperative LV mass was predictive of LVD and should be taken into consideration when determining the timing of AVR.