Transcatheter aortic valve implantation procedure does not improve intraoperative left ventricular compliance.

Kosaku Toyota, Takashi Ota, Yasuhiro Koide
Department of anaesthesia Shonan Kamakura General Hospital

Background and Goal of Study:
Transcatheter aortic valve implantation (TAVI) procedure for patients with aortic stenosis is expected to reduce left ventricular after load and following improvement of cardiac function. However, the effect of TAVI on perioperative diastolic function gets less attention. This retrospective observational study is aimed to investigate the intraoperative left ventricular compliance to assess the effect of TAVI on diastolic function. 

Materials and Methods:
18 patients who underwent transfemoral TAVI procedure using SAPIEN XT valve under general anaesthesia were recruited in this study. 
Left ventricular pressure just before balloon aortic valvuloplasty and after prosthetic valve deployment were measured using intracardiac catheter by surgeon.
Intraoperative left ventricular inflow volume before and after those procedures were calculated using transmitral flow velocity time integral and mitral valve orifice area obtained using intraoperative TEE.
Left ventricular compliance was calculated by dividing the left ventricular inflow volume by the left ventricular early to end diastolic pressure change.
Statistical analysis was performed using paired t-test. P value less than 0.05 was defined as significant difference.

Results:
The systolic blood pressure was 112.3 ± 21.3 mmHg  (mean±SD) before balloon aortic valvuloplasty, and significantly increased to 133.2 ± 30.7 ml after prosthetic valve deployment.
The left ventricular compliance just before balloon aortic valvuloplasty and just after prosthetic valve deployment were 5.3±2.2 ml/mmHg and 4.5±1.4 ml/mmHg, respectively. There was no significant difference between these left ventricular compliances. 

Conclusion:
TAVI procedure does not improve left ventricular compliance just after prosthetic valve deployment. This result indicates that the continuation of careful circulatory management is still required even after a valve deployment is successfully performed.