Transapical aortic valve implantation: The Vancouver experience.

INTRODUCTION

Off-pump transapical aortic valve implantation (TA-TAVI) through mini-thoracotomy was first performed in Vancouver, Canada in October 2005. The objective of this manuscript is to describe the Vancouver experience with 178 TA-TAVI cases in symptomatic severe aortic stenosis (AS) since 2005.

METHODS

Baseline characteristics and in-hospital outcomes were calculated for the overall cohort. To compare pre-procedure and post-procedure echocardiographic measurements, one way analysis of variance was utilized, followed by Tukey's HSD. In-hospital outcomes were compared between early and late cohorts using Z-test and chi-squared test as appropriate. Kaplan-Meier analysis was used to generate 3-year survival curves. The Log-rank test was used to compare survival between low-risk and high-risk groups, based on STS score.

RESULTS

Between October 2005-March 2012, TA-TAVI was performed in 178 patients. Mean age was 80.5±8.6 years. Congestive heart failure and renal failure were more common in the late cohort, while previous myocardial infarction was more common in the early cohort (P<0.05). Eleven patients (6.2%) had significant intra-operative complications, including death (1.7%), conversion to CPB (3.9%), and valve embolization (1.1%). In-hospital survival was 87.9%. Mean length of hospital stay was 12.2±17.1 days. In-hospital incidence of stroke was 3.4%. Bleeding (20.2% vs. 4.7%) and vascular (14.6% vs. 3.5%) complications were more common in the early cohort. Echocardiography demonstrated a significant increase in aortic valve area and decrease in mean transvalvular gradient post-procedure. These improvements were maintained throughout the 3-year follow-up period. Overall survival was 72.1% at 6 months, 67.7% at 12 months, 55.5% at 24 months, and 47.3% at 36 months. Repeated Kaplan-Meier analysis for the 2 groups stratified by STS score, demonstrated improved survival in the low-risk group (Log-rank P=0.039).

CONCLUSIONS

Among patients with symptomatic severe AS at high risk for conventional AVR, TA-TAVI is a reasonable therapeutic option with acceptable risk. Long-term survival appears to be superior in lower-risk patients.