May
Structural Heart Interventions
Issue
19 53
A “crackdown” on alternative access for TAVI
17
Carlo Di Mario Comment & Analysis The transfemoral approach is—by far—the most desirable access route for transcatheter aortic valve implantation (TAVI) for eligible patients; it was used in the TAVI arm of the recently published PARTNER 3 trial, showing superiority over surgical aortic valve replacement in low-risk patients (see page 1). Results from the National Inpatient Sample Database suggest that transfemoral access is safer and associated with lower in-hospital stay, mortality and costs, compared with the transapical approach. In this commentary, Carlo Di Mario reviews how intravascular lithotripsy may enable more patients to undergo transfemoral TAVI. ADDITIONAL ALTERNATIVE access techniques for TAVI—such as transaxillary, transcarotid and transcaval access—have been refined but have only been studied in small prospective registries. Their generalisability to all TAVI programmes is unlikely because of the demanding learning curve and hesitation on the part of many centres to embark into alternative access TAVI procedures. The use of intravascular lithotripsy to alter compliance, allowing successful dilatation in calcified infrainguinal peripheral arterial vessels, was reported in a controlled registry. These findings led to the granting of the CE mark and
Food and Drug Administration (FDA) approval for intravascular lithotripsy peripheral balloons up to 7mm in diameter. Modifying vascular compliance via intravascular lithotripsy in larger suprainguinal vessels, such as the iliac arteries, was initially reported in two cases, and demonstrated feasibility. A recently published 42-patient registry robustly showed high efficacy in allowing transfemoral access for TAVI after intravascular lithotripsy, maintaining excellent overall procedural outcomes, including vascular events and perivalvular regurgitation. Key highlights from that registry are as follows:
CT reconstruction of left iliac artery, demonstrating severe nearly circumferential calcification with lumen diameters below 5.5mm (A). Infrarenal aorta and iliac axis angiography showing coexistent severe tortuosity (B). Intravascular lithotripsy balloon inflation (4atm) at two different sites (C and D). Successful implantation of a 26mm CoreValve Evolut R prosthesis (E). Final iliac angiography showing no significant dissections (F).
42 consecutive TAVI patients with prohibitive calcified, stenotic femoral-iliac disease received intravascular lithotripsy 100% heavy calcification with a 265.5-degree average maximum arc of calcium >90% access was percutaneous and closed with a percutaneous closure system 100% transfemoral valve delivery success Zero flow-limiting dissections or perforations Zero provisional stenting. The three main obstacles to using the transfemoral route in TAVI are small vessel diameter, excessive vessel tortuosity and the presence of severe peripheral vascular disease of the iliac and/or the femoral arteries. The presence of severe circumferential arterial luminal calcification is a common finding in elderly patients with
TAVI in bicuspid stenosis provides satisfactory clinical outcomes Transcatheter aortic valve implantation (TAVI) using the current generation of balloon expandable technology leads to acceptable clinical outcomes in the bicuspid anatomy, according to an analysis of the Society of Thoracic Surgeons (STS)/American College of Cardiology (ACC) TVT Registry. Raj B Makkar (Cedars Sinai Medical Center, Los Angeles, USA) outlined outcomes following TAVI with the Sapien 3 valve (Edwards Lifesciences) in bicuspid aortic stenosis at the American College of Cardiology Scientific Session (ACC 2019; New Orleans, 16–18 March).
M
akkar said: “These data provide an argument for TAVI to be a reasonable alternative for bicuspid aortic stenosis in patients who are intermediate or high risk for aortic valve replacement, and provide a sound basis to conduct a randomised clinical trial in young patients with bicuspid aortic stenosis who are low risk for surgery.” Up to 50% of patients in the younger population require surgical valve replacement of the bicuspid aortic valves. Researchers sought to compare outcomes in native bicuspid versus tricuspid aortic valve stenosis following TAVI with the balloon expandable Sapien 3 valve in the
real-world STS/ACC TVT registry. The study population was 92,236 Sapien 3 TAVIs in the registry between June 2015 and November 2018 at 552 sites; 2,276 were bicuspid Sapien 3 patients, and 79,096 were tricuspid Sapien 3 patients. Following 1:1 propensity matching across 25 covariates including age, gender, body mass index, carotid stenosis, and peripheral arterial disease, 2,691 bicuspid Sapien 3 patients and 2,691 tricuspid Sapien 3 patients remained for comparison. The primary endpoint was mortality and stroke at 30 days and one year, with secondary endpoints procedural
complications, in-hospital adverse events, post-procedural echocardiographic assessment of the valve, and functional and health status at 30 days and one year. Device success rate was 96.5% in the bicuspid cohort and 96.6% in the tricuspid group (p=0.87), with a conversion to open surgery rate of 0.9% vs. 0.4%, respectively (p=0.03). Annulus rupture rate was 0.3% vs. 0%, respectively (p=0.02), and 0.4% of bicuspid AS patients needed a second valve, compared to 0.2% of tricuspid AS patients (p=0.16). Kaplan-Meier estimates of 30-day outcomes for all-cause mortality were
aortic stenosis and often prohibits any consideration of transfemoral TAVI. Intravascular lithotripsy may represent a straightforward technique to preserve the benefits of reduced morbidity and mortality of transfemoral TAVI in patients with calcified peripheral arterial disease. Additionally, the ease of intravascular lithotripsy and the familiarity of peripheral vascular angioplasty techniques may allow for TAVI centres of varying levels of experience and volume to adopt a strategy of routine intravascular lithotripsy followed by TAVI in carefully selected patients with prohibitive iliofemoral anatomy. Such a pathway could theoretically lead to benefits in quality of life, healthcare cost, and procedural morbidity as compared to referral to traditional alternative access TAVI or surgical valve replacement. Carlo Di Mario is at Structural Interventional Cardiology, Careggi University Hospital, Florence, Italy. 2.6% among bicuspid patients vs. 2.5 in the tricuspid group (p=0.82), with all stroke at 2.4% vs. 1.6%, respectively (p=0.02). A new pacemaker was required in 9.1% of bicuspid patients vs. 7.5% of tricuspid (p=0.03), and rates of lifethreatening bleeding were low in both groups at 0.1%. One-year all-cause mortality in the matched cohorts of bicuspid and tricuspid was 10.5% vs. 12% (HR 0.9, 95% CI 0.73–1.1; p=0.31), and one-year stroke was 3.4% vs. 3.1% (HR 1.28, 95% CI 0.91–1.79; p=0.16), respectively. Haemodynamics were equivalent in both groups, with similar improvement after matching in quality of life metrics of New York Heart Association class and Kansas City Cardiomyopathy Questionnaire. Makkar said: “This largest real-life registry of all consecutive TAVI with balloon expandable Sapien 3 valve for bicuspid compared to tricuspid was associated with similar survival at 30 days and one year, an increased risk of aortic root injury and conversion to open heart surgery, although overall rate was still low at <1%.”