Unmet Needs in TAVR: Conduction Disturbances and Management of Coronary Artery Disease.

Over the past two decades, transcatheter aortic valve replacement (TAVR) swiftly evolved from a disrupting technology towards mainstream therapy in the field of severe symptomatic aortic stenosis. A series of randomized evaluations established its role in treating severe aortic stenosis patients across all surgical risk categories, paving the way for an extension of its indications to younger low-risk patients with a longer life expectancy. Therefore, managing comorbidities and limiting procedural complications, which may affect long-term outcomes, is of paramount importance. Among those, new-onset conduction disturbances and concomitant coronary artery disease remain two of the most debated issues. In the present review, we will discuss the incidence, prognostic impact, and unmet needs of patients with post-TAVR new-onset conduction disturbances and the ongoing challenges posed by the management of concomitant coronary artery disease.

Outcome of Flow-Gradient Patterns of Aortic Stenosis After Aortic Valve Replacement: An Analysis of the PARTNER 2 Trial and Registry.

BACKGROUND: Although aortic valve replacement is associated with a major benefit in high-gradient (HG) severe aortic stenosis (AS), the results in low-gradient (LG, mean gradient <40 mm Hg) AS are conflicting. LG severe AS may be subdivided in classical low-flow (left ventricular ejection fraction <50%) and LG (CLF-LG); paradoxical low-flow (left ventricular ejection fraction ≥50% but stroke volume index <35 mL/m2) and LG; and normal-flow (left ventricular ejection fraction ≥50% and stroke volume index ≥35 mL/m2) and LG. The primary objective is to determine in the PARTNER 2 trial (The Placement of Aortic Transcatheter Valves) and registry the outcomes after aortic valve replacement of the 4 flow-gradient groups. METHODS: A total of 3511 patients from the PARTNER 2 Cohort A randomized trial (n=1910) and SAPIEN 3 registry (n=1601) were included. The flow-gradient pattern was determined at baseline transthoracic echocardiography and classified as follows: (1) HG; (2) CLF-LG; (3) paradoxical low-flow-LG; and (4) normal-flow-LG. The primary end point for this analysis was the composite of (1) death; (2) rehospitalization for heart failure symptoms and valve prosthesis complication; or (3) stroke. RESULTS: The distribution was HG, 2229 patients (63.5%); CLF-LG, 689 patients (19.6%); paradoxical low-flow-LG, 247 patients (7.0%); and normal-flow-LG, 346 patients (9.9%). The 2-year rate of primary end point was higher in CLF-LG (38.8%) versus HG: 31.8% (P=0.002) and normal-flow-LG: 32.1% (P=0.05) but was not statistically different from paradoxical low-flow-LG: 33.6% (P=0.18). There was no significant difference in the 2-year rates of clinical events between transcatheter aortic valve replacement versus surgical aortic valve replacement in the whole cohort and within each flow-gradient group. CONCLUSIONS: The LG AS pattern was highly prevalent (36.5%) in the PARTNER 2 trial and registry. CLF-LG was the most common pattern of LG AS and was associated with higher rates of death, rehospitalization, or stroke at 2 years compared with the HG group. Clinical outcomes were as good in the LG AS groups with preserved left ventricular ejection fraction compared with the HG group.

Prevalence and Impact of Prosthesis-Patient Mismatch Following Surgical Aortic Valve Replacement for Pure Aortic Regurgitation.

BACKGROUND: Prosthesis-patient mismatch (PPM) is highly prevalent among patients undergoing aortic valve replacement (AVR) to treat aortic stenosis. Data regarding the prevalence and impact of PPM on left ventricular remodeling and outcomes in patients who have undergone surgical AVR to treat pure severe aortic regurgitation (AR) are, however, scarce. METHODS: A retrospective analysis was conducted of clinical and echocardiographic data acquired from 50 consecutive patients with pure severe AR, without evidence of significant coronary artery disease, who underwent AVR between 2004 and 2010 at the authors' institution. PPM was defined as a projected in vivo effective orifice area (EOA) 0.85 cm2/m2. RESULTS: The incidence of PPM was 16%, but no severe mismatch occurred. At a mean follow up of 52 ± 39 months, event-free survival (a composite of all-cause mortality and hospitalization for cardiovascular causes) was similar between patients with and without PPM (p = 0.73). Within seven days after surgery, mean reductions in indexed left ventricular end-diastolic diameter (LVEDD) and indexed left ventricular end-systolic diameter (LVESD) were similar between patients with and without PPM [4.4 mm/m2 versus 5.0 mm/m2; p = 0.67 and 1.6 mm/m2 versus 2.2 mm/m2; p = 0.35, respectively]. At follow up, no difference was observed for mean reductions in indexed LVEDD and indexed LVESD [6.9 mm/m2 versus 7.1 mm/m2; p = 0.91 and 4.1 mm/m2 versus 5.1 mm/m2; p = 0.57, respectively], and mean improvement in left ventricular ejection fraction (4.4% versus 5.1%; p = 0.87). CONCLUSIONS: PPM occurs less frequently in patients undergoing AVR for pure severe AR than for aortic stenosis, and seems to have a less significant impact on ventricular remodeling and outcomes.

Strain analysis during exercise in patients with left ventricular hypertrophy: impact of etiology.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) and aortic stenosis (AS) may influence left ventricular (LV) systolic function, despite preservation of LV ejection fraction. The aim of this study was to determine the relative importance of cardiac afterload and myocardial hypertrophy in the potential dysfunction of myocardial deformation, at rest and during standardized exercise. METHODS: Patients with moderate to severe (≤ 1.5 cm(2)) asymptomatic AS and patients with HCM in sinus rhythm were prospectively studied using resting and exercise echocardiography during submaximal exercise. Myocardial deformations were assessed using two-dimensional strain. Exclusion criteria were altered LV ejection fraction (<50%), coronary artery disease, intra-LV obstruction > 30 mm Hg at rest, diastolic LV thickness ≥ 30 mm, and New York Heart Association class > II. Thus, 50 patients (25 with AS, 25 with HCM) were selected and matched for age, sex, rest and exercise blood pressure, degree of LV hypertrophy (defined by maximal wall thickness), and LV ejection fraction. RESULTS: Mean resting global longitudinal strain (GLS) was -14.9 ± 4.7% in patients with AS and -16.1 ± 3.9% in those with HCM (P = .30). During exercise (mean heart rate, 110 ± 10 beats/min), mean GLS was -13.9 ± 4.2% in patients with AS and -18.1 ± 5.4% in those with HCM (P = .004). GLS decreased in patients with AS but increased in those with HCM (ΔGLS, 0.9 ± 3.1% and -1.9 ± 3.2%, respectively, P = .003). The same results were observed for global circumferential strain. Mean resting global circumferential strain was -16.4 ± 5.8% in patients with AS and -17.9 ± 4.5% in those with HCM (P = .36). During exercise, mean global circumferential strain was -13.8 ± 4.1% in patients with AS and -18.6 ± 5.3% in those with HCM (P = .011). Afterload was higher, particularly during exercise, in patients with AS than in those with HCM. CONCLUSIONS: Longitudinal and circumferential LV deformation during exercise was lower in patients with AS compared with those with HCM, despite similar resting characteristics. The greater afterload observed in patients with AS led to reduced contractile reserve.

How to facilitate introduction of delivery system in transaortic transcatheter aortic valve implantation.

A new method to facilitate both introduction and handling of the delivery system in transcatheter valve implantation via the direct transaortic access (TAo-TAVI) is presented. An additional upper 2-cm incision facilitates the coaxiality between the delivery system and the aortic root.