The impact of global left ventricular afterload on left ventricular reverse remodeling after aortic valve replacement.

BACKGROUND

Conventional indices such as prosthetic valve effective orifice area (EOA) or transvalvular pressure gradients (TPG) may be unreliable in predicting left ventricular (LV) reverse remodeling after aortic valve replacement (AVR). We hypothesized that the global LV afterload, including valvular and arterial impedance, could influence LV reverse remodeling after AVR.

METHODS

Twenty-three consecutive aortic-stenosis patients (mean age, 76 ± 6.4 years) underwent isolated AVR using contemporary externally wrapped pericardial valves (19 mm, 10 patients; 21 mm 11; 23 mm, 2). Valvuloarterial impedance (Zva), a marker of global LV afterload, was measured on serial echocardiography in addition to indexed EOA, energy loss index (ELI), mean TPG, and stroke work loss. LV mass regression was used as a parameter of LV reverse remodeling.

RESULTS

The Zva significantly decreased after AVR (5.05 ± 1.7 mmHg/mL/m , pre-operatively; 3.12 ± 1.0, postoperatively; 3.13 ± 0.89, at last follow-up) in parallel with increased indexed EOA (0.46 ± 0.13 cm /m ; 1.13 ± 0.24; 0.96 ± 0.19), ELI (0.55 ± 0.21 cm /m ; 1.74 ± 0.52; 1.47 ± 0.42), and decreased mean TPG (50.2 ± 19.6 mmHg; 11.1 ± 5.4; 14.7 ± 5.8). The stroke work loss also decreased (26.3 ± 8.5 %; 8.65 ± 4.0; 9.36 ± 3.4). The Zva at last follow-up was significantly correlated with LV mass regression (correlation coefficient, r = - 0.48; P = 0.002), and was a significant predictor of LV reverse remodeling on multiple regression analysis (adjusted odds ratio, -0.43; 95% confidence interval, -31.3 to -0.67, P = 0.042), while indexed EOA, ELI, mean TPG, or systemic arterial compliance were not.

CONCLUSIONS

The postoperative Zva was significantly associated with LV mass regression after AVR. Maintaining low global LV afterload following AVR may enhance LV reverse remodeling.