Self-Expanding Transcatheter Aortic Valve Replacement in Patients With Low-Gradient Aortic Stenosis

Clinical Outcomes of Urgent or Emergency Transcatheter Aortic Valve Implantation - Insights From the Nationwide Registry of Japan Transcatheter Valve Therapies

BACKGROUND

Limited data are available for clinical outcomes in patients who underwent urgent or emergency transcatheter aortic valve implantation (TAVI). This study investigated in-hospital and 1-year outcomes and explored prognostic covariates in urgent/emergency TAVI using nationwide registry data.

METHODS AND RESULTS

Among 26,775 patients who underwent TAVI between August 2013 and December 2019, 25,495 with 1-year follow-up information were analyzed in this study. Baseline and procedural characteristics, as well as clinical adverse events, were compared between the urgent/emergency and elective TAVI groups. The primary outcome was all-cause mortality within 1 year after TAVI. Multivariable Cox regression models were constructed to identify independent predictors after urgent or emergency TAVI. Urgent or emergency TAVI was performed in 578 (2.3%) patients. The Society of Thoracic Surgeons score was significantly higher in the urgent/emergency than elective TAVI group (13.3% vs. 6.0%; P<0.001). Device success rate was comparable between the 2 groups. All-cause death-free survival within 1 year was lower in the urgent/emergency than elective TAVI group (77.2% vs. 92.2%; log rank P<0.001). Malignancy, albumin and creatinine concentrations, ejection fraction, and mean pressure gradient were associated with 1-year mortality in the urgent/emergency TAVI group.

CONCLUSIONS

Despite higher surgical risk and more comorbidities, the procedure was successfully performed in patients undergoing urgent/emergency TAVI, although it should be noted that prognosis was worse than for elective TAVI.

Left ventricular reverse remodeling after transcatheter aortic valve implantation in patients with low-flow low-gradient aortic stenosis

OBJECTIVES

Left ventricular reverse remodeling (LVRR) is associated with improved outcome in patients with heart failure. Factors associated with and predictive of LVRR in patients with low-flow low-gradient aortic stenosis (LFLG AS) after transcatheter aortic valve implantation (TAVI) and its impact on outcome were assessed.

METHODS

Pre- and postprocedural left ventricular (LV) function and volume were investigated in 219 patients with LFLG. LVRR was defined as an absolute increase of ≥10% in LV ejection fraction (LVEF) and reduction of ≥15% in LV end-systolic volume (LVESV). The primary endpoint was the combination of all-cause mortality and rehospitalization for heart failure.

RESULTS

The mean LVEF was 35.0 ± 10.0%, with a stroke volume index (SVI) of 25.9 ± 6.0 mL/m2 and LVESV of 94.04 ± 46.0 mL. At a median of 5.2 months (interquartile range, 2.7-8.1 months), 77.2% (n = 169) of the patients showed echocardiographic evidence of LVRR. A multivariate model revealed three independent factors for LVRR after TAVI: SVI of <25 mL/m2 (hazard ratio [HR], 2.31; 95% confidence interval [CI], 1.08-3.58; p < 0.01), LVEF of <30% (HR, 2.76; 95% CI, 1.53-2.91; p < 0.01), and valvulo-arterial impedance (Zva) of <5 mmHg/mL/m2 (HR, 5.36; 95% CI, 1.80-15.98; p < 0.01). Patients without evidence of LVRR showed a significantly higher incidence of the 1-year combined endpoint (32 [64.0%] vs. 75 [44.4%], p < 0.01).

CONCLUSIONS

The majority of patients with LFLG AS show LVRR after TAVI, which is associated with favorable outcomes. An SVI of <25 mL/m2, LVEF of <30%, and Zva < 5mmHg/mL/m2 represent predictors of LVRR.

Cardiac Reversibility and Survival After Transcatheter Aortic Valve Implantation in Patients With Low-Gradient Aortic Stenosis

Background Prognostic implications of transcatheter aortic valve implantation (TAVI) in low-gradient (LG) aortic stenosis (AS) remain controversial. The authors hypothesized that differences in cardiac functional recovery may solve this ongoing controversy. The aim was to evaluate clinical outcomes and the response of left ventricular (LV) function following TAVI in patients with LG AS. Methods and Results This multicenter retrospective study included 1742 patients with severe AS undergoing TAVI between January 2015 and March 2019. Patients were subdivided into low-flow (LF) LG, normal-flow (NF) LG, LF high-gradient, and NF high-gradient AS groups according to the mean gradient of the aortic valve (LG <40 mm Hg) and LV stroke volume index (LF <35 mL/m2). Outcomes and changes in echocardiographic parameters after TAVI were compared between the groups. A total of 227 patients (13%) had reduced ejection fraction, and 486 patients (28%) had LG AS (LF-LG 143 [8%]; NF-LG 343 [20%]). During a median follow-up period of 747 days, 301 patients experienced a composite end point of cardiovascular death and rehospitalization for cardiovascular events, which was higher in the LF-LG and NF-LG groups than in the high-gradient groups. LG AS was independently associated with the primary outcome (hazard ratio, 1.69; P<0.001). Among 1239 patients with follow-up echocardiography, LG AS showed less improvement in the LV mass index and LV end-diastolic volume compared with high-gradient AS after 1 year, while LV recovery was similar between the LF AS and NF AS groups. Conclusions LG AS was associated with poorer outcomes and LV recovery, regardless of flow status after TAVI. Careful evaluation of AS severity may be required in LG AS to provide TAVI within the appropriate time and advanced care afterward.

Outcomes among patients undergoing transcatheter aortic valve replacement with very low baseline gradients

Background

While there is evidence that patients with low-flow, low-gradient aortic stenosis (AS) benefit from transcatheter aortic valve replacement (TAVR), data are lacking regarding outcomes of patients with a very low gradient (VLG).

Methods

In this retrospective, single-center study of patients with severe AS who underwent TAVR, three groups were defined using baseline mean aortic valve gradient: VLG (≤25 mmHg), low gradient (LG, 26-39 mmHg), and high gradient (HG, ≥40 mmHg). The primary outcome was the composite of Kansas City Cardiomyopathy Questionnaire (KCCQ)-12 of <45, decrease in KCCQ-12 of ≥10 compared with baseline, or death at 1 year.

Results

One-thousand six patients were included: 571 HG, 353 LG, and 82 VLG. The median age was 82.1 years [interquartile range (IQR) 76.3-86.9]; VLG patients had more baseline comorbidities compared with the other groups. The primary outcome was highest at 1 year in the VLG group (VLG, 46.7%; LG, 29.9%; HG, 23.1%; p = 0.002), with no difference between groups after adjustment for baseline characteristics. At baseline, <30% of VLG patients had an excellent or good (50-100) KCCQ-12, whereas more than 75% and 50% had an excellent or good KCCQ-12 at 30-day and 1-year follow-up, respectively.

Conclusion

Although patients with VLG undergoing TAVR have a higher rate of poor outcomes at 1 year compared with patients with LG and HG severe AS, this difference is largely attributable to baseline comorbidities. Patients with severe AS undergoing TAVR have significant improvement in health status outcomes regardless of resting mean gradient.

Real world outcomes using 20 mm balloon expandable SAPIEN 3/ultra valves compared to larger valves (23, 26, and 29 mm)-a propensity matched analysis

OBJECTIVE/BACKGROUND

Small balloon expandable valves have higher echocardiographic transvalvular gradients and rates of prosthesis-patient mismatch (PPM) compared to larger valves. However, the impact of these echocardiographic findings on clinical outcomes is unknown. We sought to determine the clinical outcomes of 20 mm SAPIEN 3 (S3 BEV) compared to larger S3 BEV in relation to echocardiographic hemodynamics.

METHODS

Using the STS/ACC transcatheter valve registry, we performed a propensity-matched comparison of patients undergoing treatment of native aortic valve stenosis using transfemoral, balloon-expandable implantation of 20 mm and ≥ 23 mm S3 BEVs. Baseline and procedure characteristics, echocardiographic variables and survival were analyzed. Multivariable logistic regression was used to identify predictors of 1-year mortality.

RESULTS

After propensity matching of the 20 mm and ≥ 23 mm SAPIEN 3 valves, 3,931 pairs with comparable baseline characteristics were identified. Small valves were associated with significantly higher echocardiographic gradients at discharge (15.7 ± 7.1 mmHg vs. 11.7 ± 5.5 mmHg, p < 0.0001) and severe PPM rates (21.5% vs. 9.7%, p < 0.0001). There was no significant difference in 1-year all-cause mortality (20 mm: 13.0% vs. ≥23 mm: 12.7%, p = 0.72) or other major adverse event rates and outcomes between the two cohorts. Based on a multivariable analysis, elevated discharge mean gradient (>20 mmHg), severe PPM and the use of 20 mm versus ≥23 mm were not independent predictors of 1-year mortality.

CONCLUSION

SAPIEN 3 20 mm valves were associated with higher echocardiographic gradients, and severe PPM rates compared to larger valves but these factors were not associated with significant differences in 1-year all-cause mortality or rehospitalization.

Risk of mortality following transcatheter aortic valve replacement for low-flow low-gradient aortic stenosis

BACKGROUND

Low-flow low-gradient (LF-LG) aortic stenosis (AS) is associated with high mortality, even after transcatheter aortic valve replacement (TAVR). Further knowledge of risk indicators is needed and a clinical risk score would be desirable for optimizing patient selection and therapeutic strategy.

METHODS

The study cohort comprised of 219 consecutive LF-LG AS patients undergoing TAVR from 2008 to 2018 in two high-volume German centers. Predictive factors for one-year all-cause mortality were defined according to a Cox proportional hazard model.

RESULTS

At one-year follow-up after TAVR, 28% of patients had died. A multivariate model revealed six independent predictors of one-year mortality: history of myocardial infarction (HR 2.05, 95%CI 1.13-3.72), eGFR < 30 ml/min/1.73m² (HR 2.75, 95%CI 1.48-5.11), tricuspid regurgitation moderate or more (HR 2.06, 95%CI 1.14-3.72), stroke volume index < 25 mL/m² (HR 2.03, 95%CI 1.14-3.62), self-expandable device (HR 2.72, 95%CI 1.17-6.27), and non-transfemoral approach (HR 3.42, 95%CI 1.28-9.14). The Rhineland Risk Score (RRS) consisting of these variables (c statistic 0.75, 95%CI 0.68-0.82, p < 0.001) was superior to the EuroSCORE II (c statistic 0.63) and STS-PROM score (c statistic 0.69) at predicting one-year mortality. Patients with a RRS ≥ 8 had a prohibitive risk of one-year mortality of 67.6% (95%CI 52.0-82.4%).

CONCLUSION

In patients with LF-LG AS, history of myocardial infarction, renal dysfunction, tricuspid regurgitation, a low stroke volume index, self-expandable device, and non-femoral approach were associated with increased 1-year mortality after TAVR. The RRS might serve as a helpful tool for risk prediction and patient selection for TAVR in patients with LF-LG AS.

Aortic valve calcification is subject to aortic stenosis severity and the underlying flow pattern

Sex- and flow-related aortic valve calcification (AVC) studies are still limited in number, and data on the exact calcium quantity and distribution are scarce. Therefore, we aimed to (1) re-define the best threshold of AVC load to distinguish severe from moderate aortic stenosis (AS) in common AS entities and to (2) evaluate differences in the aortic annulus and left ventricular outflow tract (LVOT) calcium load. Nine hundred and thirty-eight patients with contrast-enhanced cardiac MSCT and moderate-to-severe aortic stenosis (AS) were retrospectively enrolled. Patients with severe AS ≤ 1.0 cm² (n = 841) were further separated into three AS entities: high gradient (HGAS, n = 370, 44.0%), paradoxical low gradient (pLGAS, n = 333, 39.6%), and classical low gradient (LGAS, n = 138, 16.4%). AVC, leaflet, and LVOT calcification were quantified. Aortic valve calcification scores were highest in severe HGAS, and lower in severe pLGAS and classical LGAS. In all severity and AS entities, the non-coronary cusp (NCC) was the most calcified one. LVOT calcification was consistently comparable between gender and AS entities. Accuracy of logistic regression was the highest in HGAS (male vs. female: AVC > 2156 Agatston units (AU), c-index 0.76; vs. AVC > 1292 AU, c-index 0.85; or AVC density > 406 AU/cm², c-index 0.82; vs. > 259 AU/cm², c-index 0.86; each p < 0.0001*) to diagnose severe AS. AVC could only be used in men to differentiate between severe LGAS and moderate AS. Data from this retrospective analysis indicate that the NCC is subject to pre-dominant degeneration throughout gender, AS severity, and several AS entities. AVC was consistently comparable in severe pLGAS and classical LGAS, but only AVC in severe LGAS could sufficiently distinguish from moderate AS in men. LVOT calcification failed to be a reliable indicator of accelerating AS.

Outcome of Flow-Gradient Patterns of Aortic Stenosis After Aortic Valve Replacement

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/m 2 ) and LG; and normal-flow (left ventricular ejection fraction ≥50% and stroke volume index ≥35 mL/m 2 ) 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.

Assessment of the prognostic significance of low gradient severe aortic stenosis and preserved left ventricular function requires the integration of the consistency of stroke volume calculation and clinical data

BACKGROUND

This study was to evaluate the prognostic significance of low gradient severe aortic stenosis (LG SAS) and preserved left ventricular ejection fraction (LVEF) with the integration of echocardiographic and clinical data.

METHODS

The study included 172 patients with LG SAS (AVAi ≤ 0.6 cm² /m² , mean aortic pressure gradient < 40 mm Hg) and LVEF (≥ 50%). LV outflow tract diameters were measured at both the aortic valve annulus and 5 mm below the annulus for the measurement consistency. Patients were divided into the low flow LG SAS (LF/LG SAS: SVi < 35mL/m² and AVAi ≤ 0.6 cm² /m² ) and normal-flow LG SAS groups (NF/LG SAS: SVi ≥ 35mL/m² and AVAi ≤ 0.6 cm² /m² ). Echocardiographic findings and clinical data were systematically analyzed with mean follow-up of 3.0 ± 1.6 years.

RESULTS

LF/LG SAS had significantly smaller AVAi, lower SVi, a higher prevalence of atrial fibrillation (28% vs 12% P = .01) and diabetes (47% vs 27% P = .007) and lower 3-year cumulative survival than NF/LG SAS. Multivariable analysis showed that dyspnea, renal dysfunction (CI 1.42-3.99, P < .01), left atrial diameter, and SVi were independently associated with an increased risk for all-cause mortality. Aortic valve intervention (AVI) improved survival in LF/LG SAS (68% vs 48%, P < .05) in comparison with medical management (HR: 4.20, CI: 1.12-15.76, P = .03), but only modestly in NF/LG SAS (75% vs 65% P > .05).

CONCLUSION

Outcome of LG SAS was independently associated with clinical characteristics. AVI likely improved outcome of LF/LG SAS who had high-risk clinical characteristics and unfavorable echocardiographic findings.

Prediction of One-Year Mortality Based upon A New Staged Mortality Risk Model in Patients with Aortic Stenosis Undergoing Transcatheter Valve Replacement

Background: In-depth knowledge about potential predictors of mortality in transcatheter aortic valve replacement (TAVR) is still warranted. Currently used risk stratification models for TAVR often fail to reach a holistic approach. We, therefore, aimed to create a new staged risk model for 1-year mortality including several new categories including (a) AS-entities (b) cardiopulmonary hemodynamics (c) comorbidities, and (d) different access routes. Methods: 737 transfemoral (TF) TAVR (84.3%) and 137 transapical (TA) TAVR (15.7%) patients were included. Predictors of 1-year mortality were assessed according to the aforementioned categories. Results: Over-all 1-year mortality (n = 100, 11.4%) was significantly higher in the TA TAVR group (TF vs. TA TAVR: 10.0% vs. 18.9 %; p = 0.0050*). By multivariate cox-regression analysis, a three-staged model was created in patients with fulfilled categories (TF TAVR: n = 655, 88,9%; TA TAVR: n = 117, 85.4%). Patients in “stage 2” showed 1.7-fold (HR 1.67; CI 1.07–2.60; p = 0.024*) and patients in “stage 3” 3.5-fold (HR 3.45; CI 1.97–6.05; p < 0.0001*) enhanced risk to die within 1 year. Mortality increased with every stage and reached the highest rates of 42.5% in “stage 3” (p_logrank < 0.0001*), even when old- and new-generation devices (p_logrank = n.s) were sub-specified. Conclusions: This new staged mortality risk model had incremental value for prediction of 1-year mortality after TAVR independently from the TAVR-era.