Citations

Background: Patient-prosthesis mismatch (PPM) is still a frequently encountered problem after aortic valve surgery for aortic stenosis(AS). Advanced planning for prevention of PPM would be beneficial. We hypothesized that identification of severe PPM based on chosen surgical valve will predict development of severe PPM after surgery. Methods: Fifty one patients (74±13yrs) with severe aortic valve stenosis who underwent aortic valve surgery had postoperative echocardiogram (TTE) within 6 months. Severe PPM was defined as effective orifice area index (EOAI)<0.65 cm2/m2.We calculated predicted severe PPM using published references values of the prosthetic valve. We used mean value and the values one standard deviation above and below. We compared these values to the actual PPM based on postoperative TTE. Results: All patients had severe AS (MG50±7 mm Hg) and an LV EF of 56±15%. Forty four patients had tissue valves implanted and 7 had mechanical valves implanted. Mean time between postoperative TTE and surgery was 39± 60 days. When the mean reference values for the valve implanted was used, only 1 patient (2%) was predicted to have severe PPM. However, based on postoperative TTE, 6 patients (13%) had severe PPM. There was no correlation between EOAI based on postop TTE and mean published reference values (Figure).When the EOAI below one SD of the published reference value was chosen, the predicted incidence of severe PPM was 38%. When the EOAI above one SD was chosen for the reference value none of the patients were predicted to have PPM. Sensitivity and specificity to identify severe PPM was 17% and 100% for mean published reference value while it was 0% and 100% for +1 SD and 83% and 68% for -1 SD. Conclusions: 1) Use of mean published reference values markedly under estimate the true incidence of post-operative PPM and has unacceptably low sensitivity. 2) Predicted occurrence of PPM was widely variable (0% to 38%) based on the published reference values. Larger studies are needed.

Background Valvuloarterial impedance (Zva) was introduced as a prognostic measure in patients with aortic stenosis (AS). However, it is unclear whether Zva has a prognostic impact on survival after surgical aortic valve replacement (AVR) in patients with severe AS with preserved ejection fraction (EF). Methods We retrospectively reviewed 929 consecutive patients who had AVR. We investigated 170 elderly patients (age >65 years, mean 76 years) who had AVR secondary to severe AS (mean gradient ≥40 mm Hg; aortic valve area ≤1 cm2; peak velocity ≥4 m/s). Patients with EF <50%, greater than moderate aortic regurgitation, prior heart surgery and concomitant mitral or tricuspid valve surgery were excluded. Zva was calculated and the patients were divided into two groups; low Zva, Zva <4.3 (n=82) and high Zva, Zva ≥4.3 (n=88). The end point was all-cause of death. Survival curves were calculated according to Kaplan-Meier method. Results Age, prevalence of hypertension, diabetes, chronic kidney disease (CKD), atrial fibrillation, symptoms, EF, E/e′ and concomitant coronary artery bypass graft were not different between the groups. Survival was not different between the groups at 5 years (70% in low Zva and 81% in high Zva; p=0.21) and for the entire follow-up period (p=0.23). Only age was a significant factor in predicting survival by multivariate analyses in Cox proportional hazards model after adjusting for Zva, CKD, atrial fibrillation and hypertension. Conclusions Our results suggest that preoperative Zva does not have a prognostic impact on postoperative survival in elderly patients with severe AS with preserved EF. Further investigation is needed to elucidate the controversial results.