The evolution of transcatheter valvular interventions: current evidence

Transcatheter valvular interventions have revolutionized valvular heart disease management. Transcatheter interventions are appealing as they are characterized by a less invasive approach, less peri-procedural issues, speedy recovery, and short hospital stay. Historical perspective and the latest evidence of the transcatheter interventions are discussed (Figure 1, Table 1). Regulatory milestones of transcatheter valvular interventions. AR, aortic valve regurgitation; AV, aortic valve; BAV, balloon aortic valvuloplasty; BMV, balloon mitral valvuloplasty; BPV, balloon pulmonary valvuloplasty; BT, breakthrough; DMR, degenerative mitral valve regurgitation; ER, extreme risk; FMR, functional mitral valve regurgitation; HR, high risk; IR, intermediate risk; LR, low risk; MV, mitral valve; MR, mitral valve regurgitation; MV, mitral valve; PV, pulmonary valve; RVOT, right ventricular outflow tract; RV-PA, right ventricle to pulmonary artery; SAVR, surgical aortic valve replacement; SMVR, surgical mitral valve replacement; TAVI, transcatheter aortic valve implantation; TPVI, transcatheter pulmonary valve implantation; TV, tricuspid valve; ViV, valve-in-valve. Transcatheter valvular interventions Temporary symptomatic relief and small haemodynamic improvement High valvular restenosis rate Reduction in mortality rate with TAVI Perioperative mortality: comparable Mortality at follow-up: not different/non-inferior Morbidity: PVL and vascular complication rates are higher with TAVI AF and bleeding: lower with TAVI PVL: reduced with newer valve generations and implantation techniques Vascular complication rate: improved with devices requiring smaller sheaths Mechanically expandable LOTUS® Edge valve: withdrawn from market due to delivery system flaws Device success: better with SAPIEN®XT than CoreValve®. Mean gradient: lower with CoreValve® Equivalent composite endpoint between Evolut® R and SAPIEN® 3 ACURATE® neo/neo2 failed to meet non-inferiority criteria of safety and clinical efficacy Portico® (precursor of Navitor®) met non-inferiority criteria for primary safety and primary efficacy outcomes TAVI vs. routine care TAVI vs. active surveillance TAVI vs. medical therapy Single arm in intermediate or low surgical risk. Acceptable safety and efficacy in terms of procedural success, mortality, haemodynamic outcomes, functional status, cardiovascular events, PPI, and hospitalization compared to native TAVI Acceptable safety and efficacy in terms of mortality, haemodynamic outcomes, and procedural success Proven feasibility of TAVI in patients with pure native AR TAVI should be reserved for inoperable patients Safe and effective procedure Leaflet coaptation Durability: no difference in MR recurrence at 5 years compared to surgery MitraClip® showed low rate of adverse events, efficacy, safety, acute procedural success, and reverse left ventricle remodelling Acceptable safety and feasibility Procedural success, functional and survival improvement CLASPIID: PASCAL® is non-inferior to MitraClip® Safety and effective in FMR Improved in MR, left ventricular dimensions, and 6-minute walk test Safe and effective in primary MR ViV implantation is a safe and good alternative to redo surgery ViR and ViMAC implantation remain at high risk of mortality and complication (LVOT obstruction and valve migration) Safe and effective Comparable to surgical valvuloplasty Low re-intervention and explantation rates Early studies: safe and effective TriClip® was effective and improved quality of life Safe and effective device Safe and effective device Small early studies showed promising results in terms of technical success, mortality, and complications Safe and effective devices TRICAVAL RCT 2020 (SAPIEN®): valve dislocation AF, atrial fibrillation; AR, aortic valve regurgitation; CAVI, caval valve implantation; CRT, cardiac resynchronization therapy; DMR, degenerative mitral regurgitation; EFS, early feasibility study; ESC, European Society of Cardiology (recommendation); FMR, functional mitral regurgitation; LVOT, left ventricular outflow tract; MAC, mitral annular calcification; MR, mitral valve regurgitation; PMC, percutaneous mitral commissurotomy; PPI, permanent pacemaker implantation; PVL, paravalvular leak; RCT, randomized controlled trial(s); TAVI, transcatheter aortic valve implantation; TEER, transcatheter edge-to-edge repair; US, The United States; ViMAC, valve-in-mitral annular calcification; ViR, valve-in-ring; ViV, valve-in-valve. The degenerative, calcific aortic valve stenosis (AS) is the most prevalent valvular disease in the ageing population. Balloon aortic valvuloplasty (BAV) was the first transcatheter AS therapy to be introduced in 1986. BAV has never been tested in large-scale randomized trials. Its informed practice was based on multi-centre registries in the 1980s. Balloon aortic valvuloplasty is reserved as a palliative option for high-risk patients not suitable for cardiac surgery or as a bridge to surgery or transcatheter aortic valve implantation (TAVI) in unstable patients or in those requiring urgent non-cardiac surgery. Moreover, the role of BAV as stand-alone therapy has faded since TAVI became commonly used. Transcatheter aortic valve implantation has transformed AS management since its introduction in 2002. Transcatheter aortic valve implantation was superior or non-inferior to surgery across the surgical risk spectrum at mid-term follow-up (i.e. 1–5 years). Although there is a dearth of data regarding clinical outcomes of low-risk younger patients and those with bicuspid aortic valve, evidence is accumulating on device durability. Randomized trials and large-scale registries demonstrated positive data about durability of TAVI devices for up to 10 years. An emerging life-time management approach especially in a low-risk younger patient is the ability to implant an appropriately sized first TAVI device that allows a repeat valve-in-valve procedure without increased concerns about coronary occlusion or patient-prosthesis mismatch. Unlike AS, the characteristics of native aortic valve regurgitation (AR) are challenging for a transcatheter intervention because of the usual absence of aortic valve calcification which offers an anchoring base in AS. Thus, AR has been deemed a relative contraindication to TAVI. Nevertheless, few TAVI devices are under investigation to address pure AR pathology with current evidence showing the feasibility of TAVI in native AR, which should be retained for inoperable patients. Mitral valve stenosis is mostly of rheumatic or degenerative origin. Percutaneous mitral commissurotomy was used in selected patients since the early 1980s. Transcatheter implantation of balloon-expandable TAVI valve in the mitral position is currently feasible in elderly or high-risk patients with severe prosthetic or native mitral stenosis or regurgitation, if there is enough anchoring calcium, or surgical ring at the mitral annulus. Recently, transapically delivered Tendyne® prosthesis became the first device to receive regulatory approval in patients with native mitral valve pathology. There are multiple trans-septal delivered devices currently being clinically tested to address native mitral valve pathology with multiple alterations and techniques to improve device anchoring and overcome potential intervention-associated left ventricular outflow tract obstruction. Mitral valve regurgitation (MR) repair is a more complex approach due to various elements that contribute to the function of mitral valve. Thus, repair methods can target leaflets and commissures, annulus, chordae tendineae, or a combination thereof. Edge-to-edge repair is the most widely used method with established efficacy and safety in high surgical risk patients with degenerative or functional MR. MitraClip® and PASCAL® have the most evidence among other repair devices. Several other devices are being investigated (e.g. Carillon®, NeoChord®, Valtech Cardioband®). Transcatheter pulmonary valvuloplasty is the treatment of choice for all patients (i.e. from neonates to octogenarians) with isolated pulmonary stenosis of more than moderate severity. More than 85% of treated patients were re-intervention-free for up to 9 years. Transcatheter pulmonary valve implantation (TPVI) has been widely accepted as a non-surgical option since 2000, to prolong the lifespan of malfunctioning right ventricle to pulmonary artery conduits. Thus, delaying cardiac surgery in patients diagnosed with congenital heart disease. In addition, TPVI allows avoiding cardiac surgery for right ventricular outflow tract (RVOT) dysfunction in both children and adults. MELODY® device was the first to obtain regulatory approval, followed by multiple devices approval for clinical use in Europe or the United States (e.g. SAPIEN®, Venus P-Valve®, Harmony®, and Pulsta® devices) making this technique feasible to a broader patient population with variable RVOT anatomy. Functional tricuspid valve regurgitation (TR) is the commonest TR phenotype. It may be atrial TR due to atrial fibrillation, or ventricular TR secondary to right heart chambers remodelling and dysfunction, left-heart valvular disease, or pulmonary hypertension. Consequently, leading to tricuspid annulus dilatation and malfunction, which is associated with poor long-term clinical outcomes including reduced survival. Surgical repair has yielded unsatisfactory outcomes in the past which rendered the transcatheter approach a suitable alternative. The experience with transcatheter devices is still in its early stage. The devices can be coaptation/repair systems or transcatheter valves (either ortho- or heterotopic). Coaptation or leaflet edge-to-edge approximation devices include TriClip® and Pascal® system which received regulatory approval at certain markets for clinical use. Other devices are still under investigation including annuloplasty and spacer technology. The orthotopic transcatheter valve started with the implantation of SAPIEN® prosthesis within a previously implanted bioprosthetic valve or ring (i.e. ‘valve-in-valve’ or valve-in-ring) as an off-label procedure. There is a plethora of transcatheter valves that address native tricuspid valve pathology such as Evoque®, Intrepid®, Cardiovalve®, and Hi-life® that are currently under investigation. Usually used as a last measure, stented valves implanted in inferior and superior vena cava (i.e. heterotopic caval valve implantation) to prevent backflow of regurgitant jet to other organs are currently being used in Europe for patients who do not have alternative valve replacement or repair options. However, the extent of a clinically meaningful benefit of these devices is not well established. Valvular heart diseases affect many patients worldwide with an increased burden among the ageing population. It is a growing cause of morbidity and mortality. Transcatheter valvular interventions have revolutionized valvular disease management with both transcatheter, and surgical interventions have improved clinical outcomes. However, there are still opportunities to identify unmet needs, expand evidence-based practice, and assess efficacy, safety, and cost-effectiveness of transcatheter interventions. All authors declare no conflict of interest for this contribution.