Impact of moderate or severe left ventricular outflow tract calcification on clinical outcomes of patients with severe aortic stenosis undergoing transcatheter aortic valve implantation with self- and balloon-expandable valves: a post hoc analysis from the SOLVE-TAVI trial

Impact of prosthesis oversizing on clinical outcomes of transcatheter aortic valve implantation using a self-expandable Evolut R valve

BACKGROUND

Transcatheter Aortic Valve Implantation (TAVI) has a growing target population after being indicated even in low-surgical-risk patients with severe symptomatic aortic stenosis. However, postoperative outcomes can be compromised due to para-valvular leakage (PVL). A lot of procedural steps have been investigated to decrease this partially avoidable operational hazard. Oversizing is a main technique to decrease the PVL, despite being itself a risky step. Many studies have been conducted to identify the optimum degree of oversizing. However, studies about oversizing by more than 20% are scarce. We aimed to evaluate the safety and efficacy of oversizing equal to or more than 20%.

RESULTS

209 patients who underwent TAVI using the self-expandable valve Evolut R were initially included. 66 patients were excluded because of the baseline conduction disturbance and lack of sufficient data, so 143 patients, 60 females and 83 males, were enrolled in our study as two groups based on the degree of oversizing: Group A included 97 patients with an oversizing index (OI) of less than 20%, and Group B included 46 patients with an OI of 20% or more. We conducted a new technique for more accurate measuring of the OI in the context of the implantation depth, and our patients were categorized using this technique. Our findings have met our primary end point in terms of the safety and efficacy of oversizing by 20% or more. There was no significant difference between both groups in terms of new-onset conduction disturbance (NOCD), with zero cases of annular rupture or coronary encroachment. In terms of efficacy, The incidence of significant PVL (grade 2 or more) in group B was less than in group A (P value 0.007). The ROC curve found that the minimum depth of implantation-derived oversizing (DIDO) to predict no significant PVL was less than 17%.

CONCLUSION

Prosthesis oversizing by 20% using the self-expandable Evolut R valve is safe and effective, with no significant effect on the conduction system, coronary encroachment, or annular injury, and warrants a greater reduction in the incidence of significant PVL.

Transcatheter Aortic Valve Implantation: Addressing the Subsequent Risk of Permanent Pacemaker Implantation

Transcatheter aortic valve implantation (TAVI) is now a commonly used therapy in patients with severe aortic stenosis, even in those patients at low surgical risk. The indications for TAVI have broadened as the therapy has proven to be safe and effective. Most challenges associated with TAVI after its initial introduction have been impressively reduced; however, the possible need for post-TAVI permanent pacemaker implantation (PPI) secondary to conduction disturbances continues to be on the radar. Conduction abnormalities post-TAVI are always of concern given that the aortic valve lies in close proximity to critical components of the cardiac conduction system. This review will present a summary of noteworthy pre-and post-procedural conduction blocks, the best use of telemetry and ambulatory device monitoring to avoid unnecessary PPI or to recognize the need for late PPI due to delayed high-grade conduction blocks, predictors to identify those patients at greatest risk of requiring PPI, important CT measurements and considerations to optimize TAVI planning, and the utility of the MInimizing Depth According to the membranous Septum (MIDAS) technique and the cusp-overlap technique. It is stressed that careful membranous septal (MS) length measurement by MDCT during pre-TAVI planning is necessary to establish the optimal implantation depth before the procedure to reduce the risk of compression of the MS and consequent damage to the cardiac conduction system.