TAVR for low-flow, low-gradient aortic stenosis: Prognostic impact of aortic valve calcification

Epicardial adipose tissue as an independent predictor of long-term outcome in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement

BACKGROUND

Accurate risk stratification is important to improve patient selection and outcome of patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR). As epicardial adipose tissue (EAT) is discussed to be involved in cardiovascular disease, it could be useful as a marker of poor prognosis in patients with severe AS undergoing TAVR.

METHODS

A total of 416 patients diagnosed with severe AS by transthoracic echocardiography were assigned for TAVR and enrolled for systematic assessment. Patients underwent clinical surveys and 5-year long-term follow-up, with all-cause mortality as the primary endpoint. EAT volume was quantified on pre-TAVR planning CTs. Patients were retrospectively dichotomized at the median of 74 cm3 of EAT into groups with low EAT and high EAT volumes. Mortality rates were compared using Kaplan-Meyer plots and uni- and multivariable cox regression analyses.

RESULTS

A total number of 341 of 416 patients (median age 80.9 years, 45% female) were included in the final analysis. Patients with high EAT volumes had similar short-term outcome (p = 0.794) but significantly worse long-term prognosis (p = 0.023) compared to patients with low EAT volumes. Increased EAT volumes were associated with worse long-term outcome (HR1.59; p = 0.031) independently from concomitant cardiovascular risk factors, general type of AS, and functional echocardiography parameters of AS severity (HR1.69; p = 0.013).

CONCLUSION

Increased EAT volume is an independent predictor of all-cause mortality in patients with severe AS undergoing TAVR. It can be easily obtained from pre-TAVR planning CTs and may thus qualify as a novel marker to improve prognostication and management of patient with severe AS.

TRIAL REGISTRATION

DRKS, DRKS00024479.

Prognostic Impact of Mitral Regurgitation Before and After Transcatheter Aortic Valve Replacement in Patients With Severe Low-Flow, Low-Gradient Aortic Stenosis

Background There is little evidence about the prognostic role of mitral regurgitation (MR) in patients with low-flow, low-gradient aortic stenosis undergoing transcatheter aortic valve replacement (TAVR). The aim of this study was to assess the prevalence and outcome implications of MR severity in patients with low-flow, low-gradient aortic stenosis undergoing TAVR, and to evaluate whether MR improvement after TAVR could influence clinical outcome. Methods and Results This study included consecutive patients with low-flow, low-gradient aortic stenosis undergoing TAVR at 2 Italian high-volume centers. The study population was categorized according to the baseline MR severity and to the presence of MR improvement at discharge. The primary outcome was the composite of all-cause death and hospitalization for worsening heart failure up to 1 year. The study included 268 patients; 57 (21%) patients showed MR >2+. Patients with MR >2+ showed a lower 1-year survival free from the primary outcome (P<0.001), all-cause death (P<0.001), and heart failure hospitalization (P<0.001) compared with patients with MR ≤2+. At multivariable analysis, baseline MR >2+ was an independent predictor of the primary outcome (P<0.001). Among patients with baseline MR >2+, MR improvement was reported in 24 (44%) cases after TAVR. The persistence of MR was associated with a significantly reduced survival free from the primary outcome, all-cause death, and heart failure hospitalization up to 1 year. Conclusions In this study, the presence of moderately severe to severe MR in patients with low-flow, low-gradient aortic stenosis undergoing TAVR portends a worse clinical outcome at 1 year. TAVR may improve MR severity in nearly half of the patients, resulting in a potential outcome benefit after discharge.

Aortic valve calcification and myocardial fibrosis determine outcome following transcatheter aortic valve replacement

AIMS

There is evidence to suggest that the subtype of aortic stenosis (AS), the degree of myocardial fibrosis (MF), and level of aortic valve calcification (AVC) are associated with adverse cardiac outcome in AS. Because little is known about their respective contribution, we sought to investigate their relative importance and interplay as well as their association with adverse cardiac events following transcatheter aortic valve replacement (TAVR).

METHODS AND RESULTS

One hundred consecutive patients with severe AS and indication for TAVR were prospectively enrolled between January 2017 and October 2018. Patients underwent transthoracic echocardiography, multidetector computed tomography, and left ventricular endomyocardial biopsies at the time of TAVR. The final study cohort consisted of 92 patients with a completed study protocol, 39 (42.4%) of whom showed a normal ejection fraction (EF) high-gradient (NEFHG) AS, 13 (14.1%) a low EF high-gradient (LEFHG) AS, 25 (27.2%) a low EF low-gradient (LEFLG) AS, and 15 (16.3%) a paradoxical low-flow, low-gradient (PLFLG) AS. The high-gradient phenotypes (NEFHG and LEFHG) showed the largest amount of AVC (807 ± 421 and 813 ± 281 mm³ , respectively) as compared with the low-gradient phenotypes (LEFLG and PLFLG; 503 ± 326 and 555 ± 594 mm³ , respectively, P < 0.05). Conversely, MF was most prevalent in low-output phenotypes (LEFLG > LEFHG > PLFLG > NEFHG, P < 0.05). This was paralleled by a greater cardiovascular (CV) mortality within 600 days after TAVR (LEFLG 28% > PLFLG 26.7% > LEFHG 15.4% > NEFHG 2.5%; P = 0.023). In patients with a high MF burden, a higher AVC was associated with a lower mortality following TAVR (P = 0.045, hazard ratio 0.261, 95% confidence interval 0.07-0.97).

CONCLUSIONS

MF is associated with adverse CV outcome following TAVR, which is most prevalent in low EF situations. In the presence of large MF burden, patients with large AVC have better outcome following TAVR. Conversely, worse outcome in large MF and relatively little AVC may be explained by a relative prominence of an underlying cardiomyopathy. The better survival rates in large AVC patients following TAVR indicate TAVR induced relief of severe AS-associated pressure overload with subsequently improved outcome.

Prognostic impact and diagnostic value of invasively derived hemodynamic measures in patients with severe aortic stenosis undergoing TAVI

BACKGROUND

Ejection time (ET), acceleration time (AT) and time between left ventricular and aortic systolic pressure peaks (T-LVAo) might be of diagnostic and prognostic use in patients with aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI).

AIM

We aimed to assess the diagnostic value and prognostic impact of invasively measured ET, AT, and T-LVAo in patients undergoing TAVI.

METHODS

A total of 1274 patients received invasive measurement of ET, AT and T-LVAo prior to TAVI. Anatomic AS severity was assessed by CT-derived aortic valve calcification density (AVC_d). Impact on all-cause mortality was retrospectively analyzed.

RESULTS

In multivariable linear regression, T-LVAo showed the strongest correlation with AVC_d. No prognostic impact of T-LVAo was found according to uni- and multivariable analyses. In contrast, using an individual C-statistic derived cutoff (C_D), patients with ET or AT ≥ C_D showed lower mortality rates compared to patients with ET or AT < C_D (1-year mortality: ET ≥ vs. < C_D: 15.01vs. 33.1%, AT ≥ vs < C_D 16.3 vs. 26.5%, p < 0.001). Moreover, multivariable analysis identified ET ≥ C_D (HR 0.61 [95% CI 0.43-0.87; p < 0.007]) to be associated with beneficial outcome after TAVI, independent from clinical risk factors and echocardiography-derived parameters.

CONCLUSION

Among the studied hemodynamic parameters T-LVAo provides the highest diagnostic value, whereas ET is an outcome predictor beyond clinical risk factors and echocardiographic parameters in AS patients following TAVI. These parameters could be of considerable use in diagnostic evaluation and risk assessment of patients scheduled for TAVI. T-LVAo (yellow): defined as time between left ventricular and aortic systolic pressure peaks. ET (green): Ejection Time defined as time from the start to flow end. AT (orange): Acceleration time defined as time from the start to the peak flow. AOP: aortic pressure, AVC: aortic valve calcification, CI: confidence interval, HGAS: high-gradient aortic stenosis, LGAS: low-gradient aortic stenosis, LVP: left ventricular pressure, SD: standard deviation.

Aortic valve calcium volume as measured by native versus contrast-enhanced computer tomography and the implications for the diagnosis of severe aortic stenosis in TAVR patients with low-gradient aortic stenosis

Background

Most of TAVR centers evaluate the calcium score in contrast-enhanced (ce) CT. We compared in this study between different methodologies to measure calcium score. We studied also the difference between patients with low-gradient (LG) and high-gradient (HG) severe aortic stenosis (AS) as regard the burden of aortic valve calcium (AVC).

Results

We measured the calcium volume and score using Agatston methodology in non-contrast (nc) CT and with modified and fixed 850 Hounsfield unit (HU) thresholds in ce CT. The calcium score and volume in ceCT using even with modified thresholds is significantly lower than the assessed score and volume in ncCT. The median (IQR) of calcium score in nc CT and in cc CT were 1288 AU (750–1815) versus 947 HU (384–2202). The median (IQR) of calcium volume in nc CT and in cc CT with modified thresholds were 701 mm³ (239–1632) versus 197 mm³ (139–532). Agatston score and calcium volume were lower in patients with LG AS than HG AS; 2069 AU (899–2477) versus 928AU (572–1284) and 1537 mm³ (644–1860) versus 286 mm³ (160–700), respectively. Only 20% of patients with LGAS had Agatston score higher than the previously supposed AVC score threshold for the diagnosis of severe AS (> 2000AU in men and > 1200 in women).

Conclusions

The diagnosis of severe LGAS should not depend on a single parameter as calcium score. In these patients, calcium score should be measured in nc CT and not in ce CT.

Artificial Intelligence Enabled Fully Automated CMR Function Quantification for Optimized Risk Stratification in Patients Undergoing Transcatheter Aortic Valve Replacement

Background

Cardiovascular magnetic resonance imaging is considered the reference standard for assessing cardiac morphology and function and has demonstrated prognostic utility in patients undergoing transcatheter aortic valve replacement (TAVR). Novel fully automated analyses may facilitate data analyses but have not yet been compared against conventional manual data acquisition in patients with severe aortic stenosis (AS).

Methods

Fully automated and manual biventricular assessments were performed in 139 AS patients scheduled for TAVR using commercially available software (suiteHEART®, Neosoft; QMass®, Medis Medical Imaging Systems). Volumetric assessment included left ventricular (LV) mass, LV/right ventricular (RV) end-diastolic/end-systolic volume, LV/RV stroke volume, and LV/RV ejection fraction (EF). Results of fully automated and manual analyses were compared. Regression analyses and receiver operator characteristics including area under the curve (AUC) calculation for prediction of the primary study endpoint cardiovascular (CV) death were performed.

Results

Fully automated and manual assessment of LVEF revealed similar prediction of CV mortality in univariable (manual: hazard ratio (HR) 0.970 (95% CI 0.943–0.997) p=0.032; automated: HR 0.967 (95% CI 0.939–0.995) p=0.022) and multivariable analyses (model 1: (including significant univariable parameters) manual: HR 0.968 (95% CI 0.938–0.999) p=0.043; automated: HR 0.963 [95% CI 0.933–0.995] p=0.024; model 2: (including CV risk factors) manual: HR 0.962 (95% CI 0.920–0.996) p=0.027; automated: HR 0.954 (95% CI 0.920–0.989) p=0.011). There were no differences in AUC (LVEF fully automated: 0.686; manual: 0.661; p=0.21). Absolute values of LV volumes differed significantly between automated and manual approaches (p < 0.001 for all). Fully automated quantification resulted in a time saving of 10 minutes per patient.

Conclusion

Fully automated biventricular volumetric assessments enable efficient and equal risk prediction compared to conventional manual approaches. In addition to significant time saving, this may provide the tools for optimized clinical management and stratification of patients with severe AS undergoing TAVR.

Impact of left ventricular outflow tract calcification in patients undergoing transfemoral transcatheter aortic valve implantation

BACKGROUND

Left ventricular outflow tract (LVOT) calcification is known to be associated with adverse outcomes after transcatheter aortic valve implantation (TAVI) in patients receiving first-generation transcatheter heart valves (THV).

AIMS

The aim of the present study was to assess the prevalence of LVOT calcification as well as its impact on outcomes in a contemporary TAVI patient cohort.

METHODS

This retrospective single-centre analysis includes 1,207 patients who underwent transfemoral TAVI between 2012 and 2018 and in whom adequate contrast-enhanced multislice computed tomgraphy (MSCT) imaging for quantification of LVOT calcification was available.

RESULTS

Significant LVOT calcification, defined as >10 mm³, was present in 37.4% (n=451) of the patient cohort. After applying propensity score matching there was no difference between patients without (w/o; n=358) and with (w; n=358) significant LVOT calcification with respect to baseline clinical characteristics. At 30 days, the composite of all-cause mortality and non-disabling/disabling stroke occurred more often in patients w LVOT calcification compared to those w/o (4.6 vs 10.1%, p=0.008). Moreover, the composite VARC-3 endpoint of device success at 30 days was in favour of patients w/o LVOT calcification (82.2% vs 73.4%, p=0.007). According to Kaplan-Meier analysis, all-cause mortality one year after TAVI was higher in patients w vs w/o LVOT calcification (12.9 vs 21.4 %, p=0.004).

CONCLUSIONS

In patients undergoing TAVI, the presence of significant LVOT calcification is common and associated with worse short-term clinical and functional outcomes as well as higher one-year mortality rates compared to patients w/o LVOT calcification.

Risk prediction in patients with low-flow, low-gradient aortic stenosis and reduced ejection fraction undergoing TAVI

OBJECTIVE

Patients with low-flow, low-gradient aortic stenosis (LFLG AS) and reduced left ventricular ejection fraction (LVEF) are known to suffer from poor prognosis after transcatheter aortic valve implantation (TAVI). This study aimed to develop a simple score system for risk prediction in this vulnerable subset of patients.

METHODS

All patients with LFLG AS with reduced EF and sufficient CT data for aortic valve calcification (AVC) quantification, who underwent TAVI at five German centres, were retrospectively included. The Risk prEdiction in patients with Low Ejection Fraction low gradient aortic stenosis undergoing TAVI (RELiEF TAVI) score was developed based on multivariable Cox regression for all-cause mortality.

RESULTS

Among all included patients (n=718), RELiEF TAVI score variables were defined as independent predictors of mortality: male sex (HR 1.34 (1.06, 1.68), p=0.013), underweight (HR 3.10 (1.50, 6.40), p=0.0022), chronic obstructive pulmonary disease (HR 1.55 (1.21, 1.99), p=0.001), pulmonary hypertension (HR 1.51 (1.17, 1.94), p=0.0015), atrial fibrillation (HR 1.28 (1.03, 1.60), p=0.028), stroke volume index (HR 0.96 (0.95, 0.98), p<0.001), non-transfemoral access (HR 1.36 (1.05, 1.76), p=0.021) and low AVC density (HR 1.44 (1.15, 1.79), p=0.0012). A score system was developed ranging from 0 to 12 points (risk of 1-year mortality: 13%-99%). Kaplan-Meier analysis for low (0-1 points), moderate (2-4 points) and high RELiEF TAVI score (>4 points) demonstrated rates of 18.0%, 29.0% and 46.1% (p<0.001) for all-cause mortality and 23.8%, 35.9% and 53.4% (p<0.001) for the combined endpoint of all-cause mortality or heart failure rehospitalisation after 1 year, respectively.

CONCLUSIONS

The RELiEF TAVI score is based on simple clinical, echocardiographic and CT parameters and might serve as a helpful tool for risk prediction in patients with LFLG AS and reduced LVEF scheduled for TAVI.

Head-to-Head Comparison of Different Software Solutions for AVC Quantification Using Contrast-Enhanced MDCT

Aortic valve calcification (AVC) in aortic stenosis patients has diagnostic and prognostic implications. Little is known about the interchangeability of AVC obtained from different multidetector computed tomography (MDCT) software solutions. Contrast-enhanced MDCT data sets of 50 randomly selected aortic stenosis patients were analysed using three different software vendors (3Mensio, CVI42, Syngo.Via). A subset of 10 patients were analysed twice for the estimation of intra-observer variability. Intra- and inter-observer variability were determined using the ICC reliability method, Bland-Altman analysis and coefficients of variation. No differences were revealed between the software solutions in the AVC calculations (3Mensio 941 ± 623, Syngo.Via 948 mm³ ± 655, CVI42 941 ± 637; p = 0.455). The best inter-vendor agreement was found between the CVI42 and the Syngo.Via (ICC 0.997 (CI 0.995-0.998)), followed by the 3Mensio and the CVI42 (ICC 0.996 (CI 0.922-0.998)), and the 3Mensio and the Syngo.Via (ICC 0.992 (CI 0.986-0.995)). There was excellent intra- (3Mensio: ICC 0.999 (0.995-1.000); CVI42: ICC 1.000 (0.999-1.000); Syngo.Via: ICC 0.998 (0.993-1.000)) and inter-observer variability (3Mensio: ICC 1.000 (0.999-1.000); CVI42: ICC 1.000 (1.000-1.000); Syngo.Via: ICC 0.996 (0.985-0.999)) for all software types. Contrast-enhanced MDCT-derived AVC scores are interchangeable between and reproducible within different commercially available software solutions. This is important since sufficient reproducibility, interchangeability and valid results represent prerequisites for accurate TAVR planning and its widespread clinical use.

True-severe stenosis in paradoxical low-flow low-gradient aortic stenosis: outcomes after transcatheter aortic valve replacement

AIMS

The ESC/EACTS guidelines propose criteria that determine the likelihood of true-severe aortic stenosis (AS). We aimed to investigate the impact of the guideline-based criteria of the likelihood of true-severe AS in patients with low-flow low-gradient (LFLG) AS with preserved ejection fraction (pEF) on outcomes following transcatheter aortic valve replacement (TAVR).

METHODS AND RESULTS

In a prospective TAVR registry, LFLG-AS patients with pEF were retrospectively categorized into high (criteria ≥6) and intermediate (criteria <6) likelihood of true-severe AS. Haemodynamic, functional, and clinical outcomes were compared with high-gradient AS patients with pEF. Among 632 eligible patients, 202 fulfilled diagnostic criteria for LFLG-AS. Significant haemodynamic improvement after TAVR was observed in LFLG-AS patients, irrespective of the likelihood. Although >70% of LFLG-AS patients had functional improvement, impaired functional status [New York Heart Association (NYHA III/IV)] persisted more frequently at 1 year in LFLG-AS than in high-gradient AS patients (7.8%), irrespective of the likelihood (high: 17.4%, P = 0.006; intermediate: 21.1%, P < 0.001). All-cause death at 1 year occurred in 6.6% of high-gradient AS patients, 10.9% of LFLG-AS patients with high likelihood [hazard ratio (HR)adj 1.43, 95% confidence interval (CI) 0.68-3.02], and in 7.2% of those with intermediate likelihood (HRadj 0.92, 95% CI 0.39-2.18). Among the criteria, only the absence of aortic valve area ≤0.8 cm2 emerged as an independent predictor of treatment futility, a combined endpoint of all-cause death or NYHA III/IV at 1 year (OR 2.70, 95% CI 1.14-6.25).

CONCLUSION

Patients with LFLG-AS with pEF had comparable survival but worse functional status at 1 year than high-gradient AS with pEF, irrespective of the likelihood of true-severe AS.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov. NCT01368250.

How valvular calcification can affect the outcomes of transcatheter aortic valve implantation

Introduction In transcatheter aortic valve implantation (TAVI), assessment of aortic valve calcification is not as standardized as aortic annulus measurement. Aortic valve calcification is important for stable anchoring of the prosthesis to the aortic annulus. However, excessive aortic valve calcification is related to procedural complications. Areas covered This review covers the methods to assess aortic valve calcification and the implications of aortic valve calcium burden for TAVI outcomes. We performed a systematic review of the literature in Pubmed and secondary sources. Furthermore, future perspectives on how to integrate aortic valve calcification assessment in the management of patients with aortic stenosis is discussed. Expert opinion Thorough assessment of the aortic valve and aortic root components including aortic valve calcification is key in the planning of TAVI. Aortic valve calcification load, location and extension are important contributors to paravalvular regurgitation. Asymmetric calcification burden with greater calcification of the left-coronary cusp related to higher need of permanent pacemaker implantation. Patients with moderate and severe left ventricular outflow tract/subannular calcification are more susceptible to aortic annular rupture. Periprocedural dislodgement of calcium form cusps and commissures is one of the main reasons of coronary artery ostial occlusion during transcatheter aortic valve implantation. Abbreviations Ao, aorta; LA, left atrium; LAA, left atrial appendage; LV, left ventricle; LVOT, left ventricular outflow tract; THV, transcatheter heart valve.