Results
In the absence of randomised controlled trial data, prospectively collected observational data offer reliable alternative for such a comparison. In this regard, we reported a large series of SC and TA cases over a long period and each limitation of no-randomized observational study was robustly addressed by a propensity score analysis. From the UK TAVI registry, 1,506 patients were suitable for our analysis. The TA arm grouped 1,216 patients, while the SC collected 290 patients. Demographic characteristics of the 1,506 patients are summarized in Table I. To reduce biases which are related to confounding variables and to the observational study per se, we performed a propensity score matching weighted analysis for LogEuroSCORE II, valve type (balloon-expandable/self-expandable), presence and severity of coronary artery disease (one, vs two, vs three coronary arteries), access route (SC vs. TA), heart rhythm (atrial fibrillation vs. sinus rhythm), and year of implantation (2015 vs. 2007). Stroke, major/minor vascular complications, major/minor bleeding, tamponade, permanent pacemaker implantation, acute kidney impairment within 7 days, renal replacement therapy, emergency valve in valve needs, paravalvular leak, balloon re-dilatation, and in operating room, 30-days, and 12-month mortality were all treated as dichotomous post-operative outcomes and their analysis is summarized in Table II. In the Cox proportional hazard model, 1,263 patients were fit to be entered and the results are presented in Table III. The median age of patients was 80 (IQR 75–85) years and 30% were female. SC access patients were marginally older than TA ones. Significantly more men were approached via SC route (p = 0.04), while the Logistic EuroSCORE was almost similar among groups (p = 0.06). The body mass index (BMI) distribution was comparable. SC access was almost exclusively used for the self-expandable device (93.9%), whereas most TA cases were for a balloon-expandable device (89.8%). Acute Kidney Injury stage III within 7 days after procedure and the renal replacement therapy rate were almost similar between groups. Conversely, the rate of permanent pacemaker implantation (PPI) in the SC (28%) was significantly greater than that in the TA (11.0%) group (p = 0.02), but this data did not affect the overall survival at our analysis. Vascular complications and major peripheral vascular injuries that required vascular surgery repair were observed with comparable frequency within groups, 1.0% in SC and 0.6% in TA. While in SC they were purely related to the access, in TA they occurred as complication of femoral percutaneous access for concomitant coronary intervention (4 cases) or accidental injury of the femoral artery, which occurred during the placement of the venous temporary intracavitary pacemaker catheter (8 cases). The rates of in-hospital acute myocardial infarction (within 72 hours after the procedure), in-hospital TIA, and stroke were not significantly different among groups (p = 1.0, p = 0.25, and p = 0.09, respectively). The rates of moderate and severe paravalvular leakage, balloon re-dilatation after valve deployment, emergency valve in valve procedure, bleeding, cardiac tamponade, emergency cardiac surgery, and in-operating room death were not significantly different among groups. Conversely, we found that in the SC the procedural time (193.24 ±77.3529 minutes) was significantly longer (p= 0.04) than that in TA (123.10 ±55.12 minutes), meanwhile the average length of hospital stay was significantly reduced (p = 0.01) in SC group (9.8 ±7.5 days) compared to TA (13.3 ±7.5 days). Moreover, the 30-days mortality was not significantly different in SC compared to TA, while the 12-months mortality was significantly higher in SC than in TA (p = 0.01). Estimates of long-term survival are represented by Kaplan-Meier curves. Long-term survival in the SC and TA groups at 8-year follow up was not significantly different (p = 0.77), as it is represented in Figure 1. Finally, based on our analysis, there was no significant difference in long-term survival between patients who received balloon-expandable devices compared to those who received self-expandable devices (p = 0.26), as it is shown in Figure 2.