Back to Annual Meeting Posters

BACKGROUND: Prosthesis-patient mismatch (PPM) is defined as a too small effective orifice area (EOA) of the prosthetic valve in relation to the patient’s body size and negatively affects postoperative outcome. The incidence of PPM after transcatheter aortic valve implantation (TAVI) may variy between 32% and 39%, despite low transprosthetic gradients. Aim of this study was to evaluate if the current concept of detecting PPM in transthoracic echocardiographic continuity equation (TTE-CE) measurements is applicable in TAVI.
METHODS: After T-AVI using the Edwards SAPIEN valve TTE-CE measurements were prospectively compared to transesophageal echocardiographic planimetric assessment (TEE-PA) and magnetic resonance imaging planimetric assessment (MRI-PA) in 33 patients. EOA was indexed to body surface area (EOAi). PPM was defined as EOAi≤0.85 cm2/m2.
RESULTS: Mean age was 81±6 years and mean logistic EuroSCORE was 23.5±13.6%. Mean preoperative EOAi was 0.36±0.1 cm2/m2. Valve size distribution and mean EOA for each imaging technique is presented in Table 1. Mean difference between TTE-CE and TEE-PA was 1.0±0.5 cm2 (p<0.001). Mean difference between TTE-CE and MRI-PA was 0.6±0.5 cm2 (p=0.003). Based on TTE-CE the incidence of PPM was 48% with a mean EOAi of 0.87±0.2 cm2/m2. There was no PPM when using planimetric assessment by TEE or MRI (mean EOAi for TEE-PA=1.40±0.2 cm2/m2, mean EOAi for MRI-PA=1.20±0.2 cm2/m2). There was no significant difference in postoperative mean transprosthetic gradients between patients with or without TTE-CE determined PPM (8.09±2.2 mmHg versus 8.5±4.0 mmHg; p=0.771).
CONCLUSIONS: Continuity equation measurements lead to underestimation of EOA of the Edwards SAPIEN valve. The conventional TTE-CE measurement may not be applicable after TAVI due to altered anatomic situation after valve stent placement. Planimetric measurements should be regarded as the realistic measures and thus the new standard to assess for EOAs after TAVI. These findings are consistent with the large in-vitro EOAs, low gradients and thus excellent antegrade hemodynamic function after TAVI.

	23 mm valve (n=6)	26 mm valve (n=21)	29 mm valve (n=6)
TTE-CE [cm2]	1.5±0.5	1.5±.02	1.8±0.1
TEE-PA [cm2]	2.0±0.3	2.5±0.2	3.2±.0.4
MRI-PA [cm2]	1.8±0.3	2.1±0.2	3.2±0.3
In-vitro [cm2]	1.6	2.1	2.97