Patient-prosthesis mismatch in aortic valve replacement: really tolerable?
OBJECTIVE
Several studies have demonstrated favorable results despite patient-prosthesis mismatch after aortic valve replacement with the use of third generation prostheses. Our aim was to determine whether this mismatch is always tolerable.


METHODS
A clinical-echocardiographic study has been performed in 339 consecutive patients who underwent aortic valve replacement because of aortic stenosis. In-hospital outcome and left ventricular mass index regression (1st month-1st year) were analyzed in the presence or absence of mismatch (indexed effective orifice area < or =0.85cm(2)/m(2)). The influence of high degrees of preoperative left ventricular mass on in-hospital mortality has also been evaluated. Left ventricular mass index was considered increased if the calculated value was over the superior quartile of the frequency distribution of all the values observed in both sexes.


RESULTS
Mismatch was found in 38% of the patients. In the absence of mismatch, the absolute mass regression was proportional to the preoperative left ventricular mass. This regression was higher in patients with increased left ventricular mass indexed (vs not increased): -38.0+/-7.8 vs -8.8+/-4.7g/m(2), p<0.01 (1st month) and -67.7+/-16.9vs -23.5+/-6.7g/m(2), p<0.05 (1st year). Mass regression was impaired in the presence of mismatch, particularly, in patients with previously increased left ventricular mass: -8.2+/-11.6 vs -5.6+/-6.3g/m(2) (p=0.83) and -24.6+/-12.6 vs -11.7+/-10.5g/m(2) (p=0.54). This worse regression was reflected on a 100% incidence of residual hypertrophy at follow-up (1st month-1st year). In the presence of mismatch, increased ventricular mass was associated with higher mortality: 14.7% vs 2.1% (p<0.01). In the absence of mismatch, ventricular mass was not associated with mortality: 4.1 vs 2.5% (p=0.55).


CONCLUSIONS
In patients with severe ventricular hypertrophy it may be important to elude patient-prosthesis mismatch to avoid a significant increase in mortality and improve ventricular mass regression. Mismatch may be tolerable in those patients with lesser degree of hypertrophy.
Fuster
Rafael García
RG
Universitary General Hospital of Valencia, Av. Tres Cruces s/n, C/ Artes Gráficas no. 4, esc. izq. pta. 3, 46014 Valencia, Spain. rgfuster@terra.com
Montero Argudo
José A
JA
Albarova
Oscar Gil
OG
Sos
Fernando Hornero
FH
López
Sergio Cánovas
SC
Codoñer
María Bueno
MB
Buendía Miñano
José A
JA
Albarran
Ignacio Rodríguez
IR
D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D015150:Echocardiography, Doppler; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods; D017052:Hospital Mortality; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000473:pathology; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011379:Prognosis; D011446:Prospective Studies; D011474:Prosthesis Design; D012016:Reference Values; D012307:Risk Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left