Transcatheter aortic valve implantation – what the general physician needs to know

Abstract

with a 5-10% risk of major adverse perioperative events and a mortality of up to 20% at one year. 5 Given this prohibitively high surgical risk, these patients have historically refused or been denied surgery with no alternative treatment option.Following the first successful human implantation in 2002, 6 transcatheter aortic valve implantation (TAVI) has rapidly developed over the past few years and is now the established treatment option for inoperable or high-risk surgical patients with severe symptomatic AS. 7 In this article, we will summarise the current evidence base and discuss factors that need to be taken into account by the general physician when considering TAVI as a treatment option, including practical aspects and future directions. Current evidenceFollowing the first successful TAVI in 2002, 6 the feasibility, efficacy and safety of the procedure were subsequently confirmed in a number of single-and multi-centre registries. 8 The Placement of AoRTic TraNscathetER Valves (PARTNER) trials were the first prospective randomised studies to compare outcomes of TAVI using the balloon-expandable (BE) Edwards Sapien valve (Edwards LifeSciences, Irvine, CA, USA) with medical management in inoperable patients 9 (cohort B) and with SAVR in patients of high surgical risk (cohort A). 10 When compared with medical therapy (plus balloon aortic valvuloplasty as required), TAVI resulted in a significant reduction in one-year mortality (30.7 vs 50.1%) that was maintained at three-year follow-up (54.1 vs 80.9%). 11 When TAVI was compared with SAVR in high-risk individuals, all-cause mortality was slightly lower with TAVI at 30 days (3.4 vs 6.5%, p=0.07) but comparable three years following implantation (44.2 vs 44%) with long-term symptomatic improvement sustained in both groups. 12 Of late, results of two more contemporary TAVI trials were reported. The non-randomised CoreValve US extremerisk pivotal trial described outcomes of TAVI using the self-expandable (SE) Medtronic CoreValve (Medtronic Inc., Minneapolis, MN, USA) in inoperable patients and demonstrated the efficacy of this treatment option with a 40% reduction in the one-year combined endpoint of all-cause mortality and stroke. 13 The randomised CoreValve US high-risk pivotal trial compared the same device with SAVR in patients deemed to be of high surgical risk. For the first time, TAVI was shown to be associated with a mortality benefit (14.2 vs 19.1%; p<0.0001 for non-inferiority and p=0.04 for superiority).With an increasingly elderly population, the incidence of aortic stenosis (AS) is rising. While surgical aortic valve replacement remains the gold standard treatment for patients with severe symptomatic AS, transcatheter aortic valve implantation (TAVI) has emerged as the treatment of choice for patients who are inoperable or high surgical risk. TAVI has been shown to be associated with a clear mortality benefit when compared with medical therapy and to be at least as good as surgical aortic valve replacement in this patient group. The last few years h...

Transcatheter aortic valve replacement; a kidney’s perspective

“…The TAVR procedure can be performed through a few approaches such as transfemoral (TF), transapical (TA) and transaortic routes. There are a few advantages to using TF-TAVR over other techniques, including the ability to use moderate sedation and local anesthetics and shorter procedure and recovery times ( 29 ). Therefore, at most centers the TF-TAVR strategy is considered first ( 13 , 14 , 28 , 29 ).…”

“…There are a few advantages to using TF-TAVR over other techniques, including the ability to use moderate sedation and local anesthetics and shorter procedure and recovery times ( 29 ). Therefore, at most centers the TF-TAVR strategy is considered first ( 13 , 14 , 28 , 29 ). However, not all patients are suitable for TF-TAVR due to advanced peripheral vascular disease; in these cases, very small or severely calcified or tortuous peripheral vessels can preclude safe placement of the access sheath ( 28 , 29 ).…”

“…Therefore, at most centers the TF-TAVR strategy is considered first ( 13 , 14 , 28 , 29 ). However, not all patients are suitable for TF-TAVR due to advanced peripheral vascular disease; in these cases, very small or severely calcified or tortuous peripheral vessels can preclude safe placement of the access sheath ( 28 , 29 ). For these patients, TA-TAVR is the method of choice ( 30 ).…”

“…During the TA-TAVR procedure, the instrumentation of the aorta may result in the dislodgement of calcium plaques and cholesterol emboli to the renal vascular bed, leading to AKI ( 35 ). Also, as discussed earlier, TA-TAVR is mostly performed under general anesthesia, which could be associated with general and renal hypoperfusion, while TF-TAVR is performed under moderate sedation and local anesthetics and is commonly not associated with hemodynamic instability ( 29 ).…”

“…During the TAVR procedure, the positioning of balloon-expandable valves requires rapid ventricular pacing via a right ventricular temporary pacing wire to reduce aortic pressure and achieve cardiac standstill ( 14 , 29 ). It has been suggested that excessive hypotension, induced by rapid ventricular pacing, may theoretically lead to a decrease in renal perfusion and renal ischemia-reperfusion injury, with an increased risk of AKI.…”