Mohammad Abdelghani

Single or dual antiplatelet therapy after PCI

The optimal duration and type of antiplatelet therapy after implantation of a drug-eluting stent (DES) remains uncertain. At the time of the first-in-man implantation of the sirolimus DES in 1999, the protocol-defined dual antiplatelet therapy (DAPT) duration was only 2 months. Subsequently, DAPT duration was extended to 1 year on the basis of anecdotal historical data, and this practice was then incorporated into clinical guidelines. For >1 decade, trialists have sought to compare the safety and efficacy of abbreviated (<6 months) and prolonged (>12 months) DAPT regimens. However, the body of evidence is limited by the heterogeneity of end points, time of randomization, and bleeding criteria used in each trial. Pharmaceutical advances led to the introduction of new ADP-receptor antagonists, which are thought to be more effective than clopidogrel. The ADP-receptor antagonists moved the focus from the optimal duration of DAPT to the potential efficacy of single antiplatelet therapy after DES implantation. In this Review, we summarize the current evidence on the duration of DAPT and the risk of bleeding and adverse cardiac events after DES implantation, and describe the pitfalls of trial interpretation. The ongoing, prospective trials to test single antiplatelet therapy after DES implantation are also discussed.

Echocardiographic and angiographic assessment of paravalvular regurgitation after TAVI: optimizing inter-technique reproducibility

AIMS Aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) is often first diagnosed by angiography and then confirmed and followed-up by transthoracic echocardiography (TTE). Consistency between both methods is important for follow-up. We sought to determine inter-technique reproducibility of the assessment of paravalvular AR after TAVI. METHODS AND RESULTS The study included 165 patients treated with a self-expanding bioprosthesis and had angiography and TTE performed at a median interval of 4 days. TTE parameters of AR severity included VARC score (the average AR grade determined by the echocardiographic VARC-II criteria), pressure half time (PHT), regurgitation jet features in long-axis views (LAX score) and colour Doppler (CD) score (=paravalvular AR jet circumferential extent (%) + LAX score). Using receiver-operating characteristics curves, the cut-points that best defined an angiographic >mild AR were identified.On TTE, AR was paravalvular in all cases, multi-jet in 28%, and predominantly (64%) detected in the commissural region between the right and left coronary sinuses. Using VARC-II criteria (combining at least two), TTE agreed with angiographic classification in 53% of cases (k = 0.14). Greater than mild AR could better be defined by one of the following combinations of criteria: (i) LAX score >4.25 and VARC-II score >1.33; (ii) CD score >11.5 and PHT <400 ms. The combination of the CD score with PHT gave the best sum of sensitivity, specificity, positive, and negative predictive values. CONCLUSIONS Agreement between angiography and TTE (using the VARC-II criteria) in the grading of post-TAVI AR is modest, and this might have contributed to the inconsistency of data on the rate and fate of paravalvular AR. Inter-technique reproducibility can be improved using a combination of CD and hemodynamic parameters.

Edge Vascular Response After Resorption of the Everolimus-Eluting Bioresorbable Vascular Scaffold - A 5-Year Serial Optical Coherence Tomography Study.

BACKGROUND The edge vascular response (EVR) has been linked to important prognostic implications in patients treated with permanent metallic stents. We aimed to investigate the relationship of EVR with the geometric changes in the everolimus-eluting bioresorbable scaffold using serial optical coherence tomography (OCT) analysis. METHODSANDRESULTS In the first-in-man ABSORB trial, 28 patients (29 lesions) underwent serial OCT at 4 different time points (Cohort B1: post-procedure, 6, 24, and 60 months [n=13]; Cohort B2: post-procedure, 12, 36, and 60 months [n=15]) following implantation of the scaffold. In Cohort B1, there was no significant luminal change at the distal or proximal edge segment throughout the entire follow-up. In contrast, there was a significant reduction of the lumen flow area (LFA) of the scaffold between post-procedure and 6 months (-1.03±0.49 mm(2)[P<0.001]), whereas between 6 and 60 months the LFA remained stable (+0.31±1.00 mm(2)[P=0.293]). In Cohort B2, there was a significant luminal reduction of the proximal edge between post-procedure and 12 months (-0.57±0.74 mm(2)[P=0.017]), whereas the lumen area remained stable (-0.26±1.22 mm(2)[P=0.462]) between 12 and 60 months. The scaffold LFA showed a change similar to that observed in Cohort B1. CONCLUSIONS Our study demonstrated a reduction in the scaffold luminal area in the absence of major EVR, suggesting that the physiological continuity of the lumen contour is restored long term. (Circ J 2016; 80: 1131-1141).

A simplified and reproducible method to size the mitral annulus: implications for transcatheter mitral valve replacement

Aims Transcatheter mitral valve replacement (TMVR) provides definitive valve replacement through a minimally invasive procedure. In the setting of TMVR, it remains unclear how relevant the differences between different mitral annular (MA) diameters are. We sought to define a simplified and reproducible method to describe the MA size. Methods and results Using cardiac computed tomography angiography (CTA) studies of 47 patients, 3D MA perimeter (P3D) was annotated. The aorto-mitral continuity was excluded from MA contour either by manual annotation (yielding a saddle-shape model) or by simple truncation at the medial and lateral trigones (yielding a D-shape model). The method of the least squares was used to generate the projected MA area (Aproj) and perimeter (Pproj). Intercommissural (IC) and septolateral (SL) diameters, Dmean = (IC diameter + SL diameter)/2, area-derived diameter (DArea = 2 x √(A/&pgr;)) and perimeter-derived diameter (DPerimeter = P/&pgr;) were measured. MA eccentricity, height, and calcification (MAC) were assessed. Thirty studies were re-read by the same and by another observer to test intra- and inter-observer reproducibility. Patients (age, 75 ± 12 years, 66% males) had a wide range of mitral regurgitation severity (none-trace in 8%, mild in 55%, moderate–severe in 37%), MA size (area: 5–16 cm2), eccentricity (−8–52%), and height (3–11 mm). MAC was seen in 11 cases, in whom MAC arc occupied 26 ± 20% of the MA circumference. DArea (36.0 ± 4.0 mm) and DPerimeter (37.1 ± 3.8 mm) correlated strongly (R2 = 0.97) and were not significantly different (P = 0.15). The IC (39.3 ± 4.6 mm) and the SL (31.4 ± 4.5 mm) diameters were significantly different from DArea (P < 0.001) while Dmean (35.4 ± 4.0 mm) was not (P = 0.5). The correlation of DArea was stronger with Dmean (R2 = 0.96) than with IC and SL diameters (R2 = 0.69 and 0.76, respectively). The average difference between DArea and Dmean was +0.6 mm and the 95% limits of agreement were 2.1 and −0.9 mm. Similar results were found when the D-shape model was applied. All MA diameters showed good reproducibility with high intraclass correlation coefficient (0.93–0.98), small average bias (0.37–1.1 mm), and low coefficient of variation (3–7%) for intra- and inter-observer comparisons. Reproducibility of DArea was lower in patients with MAC. Conclusion MA sizing by CTA is readily feasible and reproducible. Dmean is a simple index that can be used to infer the effective MA size.

Non-invasive Heart Team assessment of multivessel coronary disease with coronary computed tomography angiography based on SYNTAX score II treatment recommendations: design and rationale of the randomised SYNTAX III Revolution trial

AIMS The aim of this study was to investigate whether a Heart Team decision-making process regarding the choice of revascularisation strategy based on non-invasive coronary multislice computed tomography angiography (MSCT) assessment of coronary artery disease (CAD) is equivalent to the standard-of-care invasive angiography-based assessment in patients with multivessel CAD. METHODS AND RESULTS The SYNTAX III Revolution trial is a prospective, multicentre, all-comers randomised trial that will randomise two Heart Teams to select between surgical and percutaneous treatment according to either an invasive conventional angiography or a non-invasive MSCT angiography assessment in patients with multivessel CAD. The treatment selection by each Heart Team will be guided by the SYNTAX score II calculation. The primary endpoint is the level of agreement according to kappa of the initial decision by the Heart Teams on the modality of the revascularisation based on MSCT and angiography assessments. Secondary endpoints include agreement on the number of vessels requiring treatment and the coronary segments in need of revascularisation. CONCLUSIONS The SYNTAX III Revolution trial will provide valuable information regarding the ability of a purely non-invasive coronary anatomy assessment to select accurately the most appropriate revascularisation strategy for patients with multivessel CAD.

Acute performance of a novel restorative transcatheter aortic valve: preclinical results

AIMS The Xeltis aortic valve leaflets are made from a bioabsorbable supramolecular polymer that guides the tissue to restoring itself. It is mounted on a self-expanding nitinol frame that includes three feelers and a native leaflet clipping mechanism. We sought to investigate the acute valve performance in a preclinical setting. METHODS AND RESULTS In 33 sheep, 26 mm Xeltis aortic valves were transapically implanted in a 23 mm native annulus. Aortography (analysable, n=28) and echocardiography (analysable, n=20) images were acquired immediately after implantation of the Xeltis aortic valve to assess the acute device performance. On echocardiography, transvalvular peak pressure gradient (PG) was 7.4 (IQR: 6.0-8.9) mmHg, mean PG was 4.0 (IQR: 3.0-5.0) mmHg, and effective orifice area was 2.2 (IQR: 1.6-2.5) cm2. Trace (n=6), mild (n=2) and no (n=12) transvalvular aortic regurgitation (AR) were seen. Likewise, no paravalvular AR was detected in 7 cases, whereas trace, mild and moderate were seen in 7, 5 and 1 cases, respectively. On quantitative videodensitometric AR (VD-AR) assessment, a median value of 6% (IQR: 1-12%) of AR was seen. Three cases had a VD-AR superior to 17%, which has a prognostic significance. Out of these three cases, two had echocardiographic assessment available, which showed mild and moderate paravalvular regurgitation due to inadequate leaflet clipping. CONCLUSIONS In a transapical ovine model, the novel restorative transcatheter aortic valve with bioabsorbable leaflets demonstrated good haemodynamic performance comparable to commercially available devices. The highly porous polymeric leaflets demonstrated good competence immediately after implantation with no cases having >mild transvalvular AR.

Transcatheter Aortic Valve Implantation in Lower-Risk Patients With Aortic Stenosis Is It Justified to Be the Preferred Treatment?

Transcatheter aortic valve implantation underwent progressive improvements until it became the default therapy for inoperable patients, and a recommended therapy in high-risk operable patients with symptomatic severe aortic stenosis. In the lower-risk patient strata, a currently costly therapy that still has important complications with questionable durability is competing with the established effective and still-improving surgical replacement. This report tries to weigh the clinical evidence, the recent technical improvements, the durability, and the cost-effectiveness claims supporting the adoption of transcatheter aortic valve implantation in intermediate-low risk patients. The importance of appropriate patients’ risk stratification and a more comprehensive approach to estimate that risk are also emphasized in the present report.

The interaction of de-novo and pre-existing aortic regurgitation after TAVI: Insights from a new quantitative aortographic technique.

AIMS The aim of this study was to evaluate the intermediate-term clinical impact of aortic regurgitation (AR) after transcatheter aortic valve implantation (TAVI) using a novel quantitative angiographic method taking into account the influence of pre-existing AR. METHODS AND RESULTS AR after TAVI was quantified in 338 patients (age 82 [78-86] years; 55% male) and the influence on intermediate-term all-cause mortality was evaluated. In 228 aortograms, AR was quantitated using a dedicated videodensitometric method focused in the left ventricular outflow tract (LVOT-AR). Patients with LVOT-AR >0.17 had a significantly increased all-cause mortality at three years, compared with patients who had LVOT-AR ≤0.17 (adjusted hazard ratio [HR]: 1.73, 95% confidence interval [CI]: 1.05-2.86, p=0.032). Taking the influence of pre-existing AR into account, patients with post-procedural LVOT-AR >0.17 and ≤mild pre-existing AR had a significantly increased mortality at two years, compared to patients with LVOT-AR >0.17 and >mild pre-existing AR (HR: 2.55, 95% CI: 1.16-5.58, p=0.029). In those with >mild pre-existing AR (n=70), post-TAVI LVOT-AR >0.17 was not associated with increased mortality (HR: 0.77, 95% CI: 0.31-1.91, p=0.578). CONCLUSIONS AR after TAVI could be quantitated utilising LVOT-AR. The cut-point of >0.17 indicates a significant AR pertaining to increased intermediate-term mortality, especially in those with no significant pre-existing AR.

Intracoronary optical coherence tomography: Clinical and research applications and intravascular imaging software overview

By providing valuable information about the coronary artery wall and lumen, intravascular imaging may aid in optimizing interventional procedure results and thereby could improve clinical outcomes following percutaneous coronary intervention (PCI). Intravascular optical coherence tomography (OCT) is a light‐based technology with a tissue penetration of approximately 1 to 3 mm and provides near histological resolution. It has emerged as a technological breakthrough in intravascular imaging with multiple clinical and research applications. OCT provides detailed visualization of the vessel following PCI and provides accurate assessment of post‐procedural stent performance including detection of edge dissection, stent struts apposition, tissue prolapse, and healing parameters. Additionally, it can provide accurate characterization of plaque morphology and provides key information to optimize post‐procedural outcomes. This manuscript aims to review the current clinical and research applications of intracoronary OCT and summarize the analytic OCT imaging software packages currently available.

Quantification by optical coherence tomography imaging of the ablation volume obtained with the Orbital Atherectomy System in calcified coronary lesions

AIMS Recently, favourable procedural 30-day and one-year outcomes with the Diamondback 360 Orbital Atherectomy System (OAS) in the treatment of severely calcified lesions have been reported. The purpose of this study was to assess the therapeutic mechanism and efficacy of the OAS with optical coherence tomography (OCT) imaging. METHODS AND RESULTS This was an observational imaging study in 18 patients with complex calcified coro-nary artery lesions who underwent percutaneous coronary intervention with the OAS. Pre-OAS and post-OAS OCT analyses demonstrated that the minimum lumen area (MLA) increased from 2.07±0.66 mm2 to 2.38±0.68 mm2 with a lumen volume increase of 9.68±17.22 mm3 in the ablated segment with a length of 30.7±13.1 mm. The maximal vessel injury (dissection) involved the intima in 39% and the media in 6% of the study population. To eliminate the influence of post-OAS vasoconstriction, the ablation area was measured with the interpolated original lumen surface by comparing the endoluminal border of the pre-OAS image. The ablation area at the maximal ablated cross-section was 0.55±0.41 mm2, and the ablation volume by OAS was 2.68±2.80 mm3. CONCLUSIONS OAS effectively ablated coronary calcified tissue with some degree of intimal dissection. OCT imaging can be used to assess the total ablation volume after orbital atherectomy.