Geeteshwar Mangat

Subclinical leaflet thrombosis in surgical and transcatheter bioprosthetic aortic valves: an observational study

BACKGROUND Subclinical leaflet thrombosis of bioprosthetic aortic valves after transcatheter valve replacement (TAVR) and surgical aortic valve replacement (SAVR) has been found with CT imaging. The objective of this study was to report the prevalence of subclinical leaflet thrombosis in surgical and transcatheter aortic valves and the effect of novel oral anticoagulants (NOACs) on the subclinical leaflet thrombosis and subsequent valve haemodynamics and clinical outcomes on the basis of two registries of patients who had CT imaging done after TAVR or SAVR. METHODS Patients enrolled between Dec 22, 2014, and Jan 18, 2017, in the RESOLVE registry, and between June 2, 2014, and Sept 28, 2016, in the SAVORY registry, had CT imaging done with a dedicated four-dimensional volume-rendered imaging protocol at varying intervals after TAVR and SAVR. We defined subclinical leaflet thrombosis as the presence of reduced leaflet motion, along with corresponding hypoattenuating lesions shown with CT. We collected data for baseline demographics, antithrombotic therapy, and clinical outcomes. We analysed all CT scans, echocardiograms, and neurological events in a masked fashion. FINDINGS Of the 931 patients who had CT imaging done (657 [71%] in the RESOLVE registry and 274 [29%] in the SAVORY registry), 890 [96%] had interpretable CT scans (626 [70%] in the RESOLVE registry and 264 [30%] in the SAVORY registry). 106 (12%) of 890 patients had subclinical leaflet thrombosis, including five (4%) of 138 with thrombosis of surgical valves versus 101 (13%) of 752 with thrombosis of transcatheter valves (p=0·001). The median time from aortic valve replacement to CT for the entire cohort was 83 days (IQR 33-281). Subclinical leaflet thrombosis was less frequent among patients receiving anticoagulants (eight [4%] of 224) than among those receiving dual antiplatelet therapy (31 [15%] of 208; p<0·0001); NOACs were equally as effective as warfarin (three [3%] of 107 vs five [4%] of 117; p=0·72). Subclinical leaflet thrombosis resolved in 36 (100%) of 36 patients (warfarin 24 [67%]; NOACs 12 [33%]) receiving anticoagulants, whereas it persisted in 20 (91%) of 22 patients not receiving anticoagulants (p<0·0001). A greater proportion of patients with subclinical leaflet thrombosis had aortic valve gradients of more than 20 mm Hg and increases in aortic valve gradients of more than 10 mm Hg (12 [14%] of 88) than did those with normal leaflet motion (seven [1%] of 632; p<0·0001). Although stroke rates were not different between those with (4·12 strokes per 100 person-years) or without (1·92 strokes per 100 person-years) reduced leaflet motion (p=0·10), subclinical leaflet thrombosis was associated with increased rates of transient ischaemic attacks (TIAs; 4·18 TIAs per 100 person-years vs 0·60 TIAs per 100 person-years; p=0·0005) and all strokes or TIAs (7·85 vs 2·36 per 100 person-years; p=0·001). INTERPRETATION Subclinical leaflet thrombosis occurred frequently in bioprosthetic aortic valves, more commonly in transcatheter than in surgical valves. Anticoagulation (both NOACs and warfarin), but not dual antiplatelet therapy, was effective in prevention or treatment of subclinical leaflet thrombosis. Subclinical leaflet thrombosis was associated with increased rates of TIAs and strokes or TIAs. Despite excellent outcomes after TAVR with the new-generation valves, prevention and treatment of subclinical leaflet thrombosis might offer a potential opportunity for further improvement in valve haemodynamics and clinical outcomes. FUNDING RESOLVE (Cedars-Sinai Heart Institute) and SAVORY (Rigshospitalet).

Concomitant mitral annular calcification and severe aortic stenosis: prevalence, characteristics and outcome following transcatheter aortic valve replacement

Aims Calcified aortic stenosis (AS) and mitral annular calcification (MAC) have certain similar etiology and pathophysiological mechanisms. MAC is frequently encountered in pre-procedural computed tomography (CT) imaging of patients that undergo transcatheter aortic valve replacement (TAVR), but its prognostic implications for these patients have not been thoroughly investigated. This study sought to evaluate the prevalence of MAC among patients with severe AS and to assess the clinical implications of MAC on these patients during and following TAVR. Methods and results Consecutive patients that underwent TAVR were compared according to the existence of MAC and its severity in pre-TAVR CT scans. From the entire cohort of 761 patients, 49.3% had MAC, and 50.7% did not have MAC. Mild MAC was present in 231 patients (30.4%), moderate MAC in 72 patients (9.5%), and severe MAC in 72 patients (9.5%). Thirty-day mortality and major complications were similar between patients with and without MAC. In a multivariable survival analysis, severe MAC was found to be an independent strong predictor of overall mortality following TAVR (all-cause mortality: hazards ratio [HR] 1.95, 95% confidence interval [CI] 1.24–3.07, P = 0.004; cardiovascular mortality: HR 2.35, 95% CI 1.19–4.66; P = 0.01). Severe MAC was also found to be an independent strong predictor of new permanent pacemaker implantation (PPI) after TAVR (OR 2.83, 95% CI 1.08–7.47; P = 0.03). Conclusion Half of the patients with severe AS evaluated for TAVR were found to have MAC. Severe MAC is associated with increased all-cause and cardiovascular mortality and with conduction abnormalities following TAVR and should be included in future risk stratification models for TAVR.

Impact of Preprocedural B-Type Natriuretic Peptide Levels on the Outcomes After Transcatheter Aortic Valve Implantation.

There are limited data on the effect of baseline B-type natriuretic peptide (BNP) on the outcome after transcatheter aortic valve implantation (TAVI). We investigated the influence of baseline BNP levels on the short-term and midterm clinical outcomes after TAVI. During a 3-year period, 780 patients with severe aortic stenosis underwent TAVI at our institute and had baseline BNP levels. We compared the high, mid, and low tertiles of BNP levels. TAVI end points, device success, and adverse events were considered according to the Valve Academic Research Consortium 2 definitions. Device success was significantly lower for patients with high BNP (98.1% vs 96.2% vs 91.9% for the low, mid, and high BNP tertiles, respectively; p = 0.003). All-cause mortality up to 30 days was 1.2% (3 of 260) versus 2.3% (6 of 260) versus 5% (13 of 260), respectively (p = 0.03). Six-month mortality rate was 4.1% (10 of 241) for the low BNP tertile, 5% (12 of 239) for the mid BNP tertile, and 17.1% (40 of 234) for the high BNP tertile (p <0.001). In the multivariate model, high tertile of baseline BNP was found to be significantly associated with all-cause mortality (hazard ratio 3.3, 95% confidence interval 1.64 to 6.48; p = 0.001). In conclusion, elevated BNP levels are associated with increased short-term and midterm mortality after TAVI. We recommend measurement of baseline BNP as part of risk stratification models for TAVI.

Impact of body mass index on the outcomes following transcatheter aortic valve implantation

To investigate the influence of body mass index (BMI) on short‐ and midterm outcomes following transcatheter aortic valve implantation (TAVI).

Optimal sizing for SAPIEN 3 transcatheter aortic valve replacement in patients with or without left ventricular outflow tract calcification

AIMS The impact of left ventricular outflow tract calcification (LVOT-CA) on SAPIEN 3 transcatheter aortic valve replacement (S3-TAVR) is not well understood. The aims of the present study were to determine optimal device sizing for S3-TAVR in patients with or without LVOT-CA and to evaluate the influence of residual paravalvular leak (PVL) on survival after S3-TAVR in these patients. METHODS AND RESULTS This study analysed 280 patients (LVOT-CA=144, no LVOT-CA=136) undergoing S3-TAVR. Optimal annular area sizing was defined as % annular area sizing related to lower rates of ≥mild PVL. Annular area sizing was determined as follows: (prosthesis area/CT annulus area-1)×100. Overall, ≥mild PVL was present in 25.7%. Receiver operating characteristic curve analysis for prediction of ≥mild PVL in patients with LVOT-CA showed that 7.2% annular area sizing was identified as the optimal threshold (area under the curve [AUC] 0.71). Conversely, annular area sizing for no LVOT-CA appeared unrelated to PVL (AUC 0.58). Aortic annular injury was seen in four patients (average 15.5% annular area oversizing), three of whom had LVOT-CA. Although there was no difference in one-year survival between patients with ≥mild PVL and without PVL (log-rank p=0.91), subgroup analysis demonstrated that patients with ≥moderate LVOT-CA who had ≥mild PVL had lower survival compared to patients with ≥mild PVL and none or mild LVOT-CA (log-rank p=0.010). CONCLUSIONS In the setting of LVOT-CA, an optimally sized S3 valve is required to reduce PVL and to increase survival following TAVR.

Outcome of paravalvular leak repair after transcatheter aortic valve replacement with a balloon-expandable prosthesis.

Significant paravalvular leak (PVL) occurs in up to 13% of patients after transcatheter aortic valve replacement (TAVR) with a balloon‐expandable bioprosthesis. Transcatheter PVL repair has emerged as a less invasive alternative for this problem.

Relation Between Left Ventricular Outflow Tract Calcium and Mortality Following Transcatheter Aortic Valve Implantation

Left ventricular outflow tract (LVOT) calcium is known to be associated with adverse procedural outcomes after transcatheter aortic valve implantation (TAVI), yet its effect on midterm outcomes has not been previously investigated. The aim of this study was to determine the influence of LVOT calcium on 2-year mortality after TAVI. A total of 537 consecutive patients underwent TAVI and 2 groups were established, stratified based on the severity of the LVOT calcium. The primary outcome was 2-year overall survival rate. The ≥moderate LVOT calcium group included 107 patients (19.9%) and the remaining 430 patients (80.1%) were included in the ≤mild LVOT calcium group. After a median follow-up of 717 days (interquartile range 484 to 828), the Kaplan-Meier analysis revealed that the 2-year overall survival probability was significantly lower in the ≥moderate LVOT calcium group than in the ≤mild LVOT calcium group (log-rank p = 0.001). On a Cox hazard model, ≥moderate LVOT calcium was associated with increased all-cause mortality after TAVI (hazard ratio 1.74, p = 0.009). In the subgroup analysis, based on valve designs, SAPIEN 3-TAVI done in the setting of ≥moderate LVOT calcium had a relatively similar survival probability as those of ≤mild LVOT calcium (log-rank p = 0.18), which is in contrast with older generation valves (log-rank p = 0.001). In conclusion, patients with ≥moderate LVOT calcium were shown to have a lower survival probability in the midterm follow-up after TAVI, compared with those with ≤mild LVOT calcium. Patients with high-grade LVOT calcium should be monitored with longer-term follow-ups after TAVI.

Severe aortic stenosis with low aortic valve calcification: characteristics and outcome following transcatheter aortic valve implantation

Aims High aortic valve calcification (AVC) assessed with CT may be used to differentiate between severe and non-severe aortic stenosis (AS). Nonetheless, in some cases patients with low calcification are diagnosed with haemodynamically severe AS. The prevalence, mechanism of valve stenosis and implications for transcatheter aortic valve implantation (TAVI) of low AVC severe AS remain unclear. We assessed the clinical and haemodynamic characteristics and the outcome of patients with severe AS and low AVC that undergo TAVI. Methods and results Ninety-three patients that had low CT aortic valve calcification score (AVCS) were compared to 470 patients with high AVCS. High gradient severe AS was found among 53.8% (50/93) of the patients with low AVCS vs. 86% (404/470) of the patients with high AVCS (P < 0.001). Device success rate was similar between both groups. There were significantly lower rates of postprocedural paravalvular regurgitation (PVR) in the low AVCS group (≥ mild PVR: 12.9% vs. 23.6%; P = 0.03). Overall, there were only two cases (0.4%) of valve embolization in patients with high AVCS and 1 (1.1%) in patients with low AVCS (P = 0.42). Thirty-day mortality and major complications were similar between groups. Conclusion Balloon-expandable TAVI in patients with a mildly calcified aortic valve was not associated with increased risk of valve embolization or mortality. We demonstrated high device success and lower rates of PVR for these patients. These findings suggest that in patients with evidence of haemodynamically severe AS at echocardiography, the presence of low ACVS at CT should not preclude the consideration of TAVI.

Characteristics and outcome following transcatheter aortic valve replacement in patients with severe aortic stenosis with low flow

AIMS Only a few studies have examined the respective impact of low flow (LF), low gradient (LG) and low ejection fraction (LEF) on outcomes following transcatheter aortic valve replacement (TAVR). The purpose of this study was to assess the impact of preprocedural stroke volume index, aortic valve gradient, left ventricular ejection fraction (LVEF) and different flow/gradient/LVEF patterns on the clinical outcomes of patients with severe aortic stenosis (AS) who undergo TAVR. METHODS AND RESULTS We analysed the clinical, echocardiographic, and outcome data collected in 770 patients with AS who underwent TAVR. Overall, 357 patients had normal flow (NF) AS and 413 had LF AS. Patients with NF had similar one-year mortality (12.0% vs. 15.0%, p=0.23) compared with those in the LF group. Overall, patients with NF and/or HG had lower one-year mortality rates (11.7 to 13%) compared to those with paradoxical LF-LG with NEF (19%) and those with classical LF-LG with LEF (27.3%). Low mean gradient was an independent predictor of all-cause mortality (hazard ratio: 1.14, per 10 mmHg decrease, p=0.02). Despite significant association in univariable analyses, LF and LEF were not found to be predictors of outcomes in multivariable analyses. CONCLUSIONS Patients with HG and those with NF-LG have low one-year mortality rates following TAVR, whereas those with classical LF-LG and LEF and those with paradoxical LF-LG and NEF have high and intermediate risk of mortality, respectively. In contradiction to previous reports, LG but not LF or LEF is an independent predictor of late mortality in high-risk patients with severe AS undergoing TAVR.

Effect of ascending aortic dimension on acute procedural success following self-expanding transcatheter aortic valve replacement: A multicenter retrospective analysis

AIMS Self-expanding (SE) valves are characterized with long stent frame design and the radial force of the device exists both in the inflow and outflow level. Therefore, we hypothesized that device success of SE-valves may be influenced by ascending aortic dimensions (AAD). The aim of this study was to determine the influence of AAD on acute device success rates following SE transcatheter aortic valve replacement (TAVR). METHODS & RESULTS In 4 centers in the United States and Asia, 214 consecutive patients underwent SE-TAVR. Outcomes were assessed in line with Valve Academic Research Consortium criteria. AAD was defined as the sum of the short and long axis aortic diameter divided by 2. Overall, device success rate was 85.0%. Multivariate analysis revealed that increased AAD (Odds ratio 1.27) and % oversizing (Odds ratio 0.88) were found to be independent predictors of unsuccessful device implantation. The c-statistic of the model for device success was area under the curve 0.79, sensitivity 81.3% and specificity 44.0%. Co-existence of several risk factors was associated with an exponential fall to 64.2% in device success rate. For a large AAD, however, optimally oversized SE-valves (threshold 16.2%) resulted with high device success rates compared to suboptimal oversizing (88.6% vs. 64.2%, p=0.005). CONCLUSIONS Larger AAD and smaller degrees of oversizing were confirmed to be the most relevant predictors of unsuccessful device implantation following SE-valve implantations. Optimal oversizing of great significance was noted, particularly that with a large AAD.