Efficacy of transcatheter aortic valve implantation in patients with aortic stenosis and reduced LVEF. A systematic review

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.

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.

Outcomes of Transcatheter Aortic Valve Replacement in Patients With Severely Reduced Left Ventricular Systolic Function in the Low Systolic Function and Transcatheter Aortic Valve Implantation (LOSTAVI) International Registry

Transcatheter aortic valve replacement (TAVR) is an established therapy for severe, symptomatic aortic valve stenosis even in patients with impaired left ventricular systolic function. However, there is uncertainty on the clinical effectiveness of the currently available TAVR devices in patients with reduced left ventricular ejection fraction (LVEF). The LOSTAVI (Low Systolic function and Transcatheter Aortic Valve Implantation) registry is a retrospective observational study using baseline, procedural, discharge, and long-term follow-up details. A total of 3 groups of interest were distinguished: extremely reduced LVEF (<25%), severely reduced LVEF (25% to 30%), and reduced LVEF (31% to 35%). Unadjusted and adjusted analyses were carried out for in-hospital and follow-up outcomes. A total of 923 patients were included from 12 centers, with 146 patients (16%) with LVEF <25%, 425 (46%) with LVEF 25% to 30%, and 352 (38%) with LVEF 31% to 35%. Several baseline and procedural features were different across groups, including age, risk, functional class, and prevalence of bicuspid disease (all p <0.05). In-hospital mortality was similar in the 3 groups (7 [4.8%], 18 [4.2%], and 7 [2.0%], respectively, p = 0.661), but major adverse events were more common in those with extremely reduced and severely reduced LVEF (19 [13%], 53 [13%], and 25 [7.1%], respectively, p = 0.024). The 12-month follow-up confirmed the significant detrimental impact of reduced LVEF on both death (21 [14%], 49 [12%], and 25 [7.1%], respectively, p = 0.024) and major adverse events (37 [25%], 89 [21%], and 53 [15%], respectively, p = 0.016). The adjusted analysis confirmed the significant prognostic role of LVEF on both outcomes, whereas TAVR device type was not associated with death or major adverse events (all p >0.05). In conclusion, TAVR yields favorable early and 1-year results in patients with reduced LVEF, including those with extremely depressed systolic dysfunction. However, reduced LVEF still represents a major adverse prognostic factor for both short- and mid-term outcomes.

Clinical and Echocardiographic Characteristics of Flow-Based Classification Following Balloon-Expandable Transcatheter Heart Valve in PARTNER Trials

BACKGROUND

Current expected normal echocardiographic measures of transcatheter heart valve (THV) function were derived from pooled cohorts of the randomized trials; however, THV function by flow state before or following transcatheter aortic valve replacement (TAVR) has not been previously reported.

OBJECTIVES

This study sought to assess the expected normal echocardiographic hemodynamics for the balloon-expandable THV grouped by stroke volume index (SVI).

METHODS

Patients with severe aortic stenosis enrolled in PARTNER (Placement of Aortic Transcatheter Valves) 1 (high/extreme surgical risk), PARTNER 2 (intermediate surgical risk), or PARTNER 3 (low surgical risk) trials with complete core laboratory echocardiography were included. Patients were grouped by low-flow (SVI_LOW <35 mL/m²) and normal-flow (SVI_NORMAL ≥35 mL/m²). Mean gradient, effective orifice area (EOA), and Doppler velocity index (DVI) were collected at baseline and at 30 days post-TAVR. Prosthesis-patient mismatch (PPM) was both calculated and predicted from normative data, using defined criteria.

RESULTS

In the entire population (N = 4,991), mean age was 81.8 years, 58% of patients were male, and 42% had low flow. Compared with patients with baseline SVI_NORMAL, those with SVI_LOW were more likely to be male; have more comorbidities; and lower left ventricular ejection fraction, mean gradient, and EOA. Post-TAVR, SVI_LOW increased to SVI_NORMAL in 17.3% and SVI_NORMAL decreased to SVI_LOW in 12.3% of patients. Using baseline SVI, follow-up EOA, mean gradient, and DVI for patients with SVI_LOW tended to be lower than for patients with SVI_NORMAL. Using the post-TAVR SVI, follow-up EOA, mean gradient, and DVI were significantly lower for patients with SVI_LOW than for those with SVI_NORMAL (P < 0.001 for all). The incidence of calculated, but not predicted, severe PPM was higher in patients with low flow than it was in patients with normal flow, suggesting pseudo-PPM in the presence of low flow.

CONCLUSIONS

This study demonstrates that flow affects THV hemodynamics and both baseline and follow-up SVI should be considered when predicting THV hemodynamics prior to TAVR, as well as assessing valve function following valve implantation.

The role of TAVR in patients with heart failure: do we have the responses to all questions?

Severe aortic stenosis (AS) is the most prevalent valvular heart disease in developed countries. Heart failure (HF) is a frequent comorbidity of this condition and represents a diagnostic and therapeutic challenge. The spectrum of both conditions has become progressively wider in the last decade; HF has been divided in three groups according to left ventricular ejection fraction (LVEF) and severe AS has been reclassified into four groups according to aortic valve (AV) gradient, AV flow measured by LV stroke index, and LVEF. Although all four AS types may be found in patients with signs and symptoms of HF, low-flow AS with low or normal gradient is the most common type in these patients. Several studies have documented that patients with low-flow severe AS have a higher mortality risk than patients with normal-flow and high-gradient AS not only during the natural progression of the disease, but also after either interventional or surgical AV replacement. Existing data support transcatheter AV replacement (TAVR) in patients with severe AS, irrespective of AV gradient, AV flow, and LVEF. Controversial issues, however, are still present on this topic, which has not been adequately addressed by large studies and trials. This clinical review summarizes the epidemiology of the different HF types in patients with severe AS, as well as the impact of HF and LVEF on clinical outcomes of AS patients either untreated or after AV replacement. In particular, we addressed the influence of AV gradient and AV flow on all-cause and cardiovascular mortality in AS patients after TAVR.

Imaging Challenges in Patients with Severe Aortic Stenosis and Heart Failure: Did We Find a Way Out of the Labyrinth?

Aortic stenosis (AS) is the most frequent degenerative valvular disease in developed countries. Its incidence has been constantly rising due to population aging. The diagnosis of AS was considered straightforward for a very long time. High gradients and reduced aortic valve area were considered as "sine qua non" in diagnosis of AS until a growing body of evidence showed that patients with low gradients could also have severe AS with the same or even worse outcome. This completely changed the paradigm of AS diagnosis and involved large numbers of parameters that had never been used in the evaluation of AS severity. Low gradient AS patients may present with heart failure (HF) with preserved or reduced left ventricular ejection fraction (LVEF), associated with changes in cardiac output and flow across the aortic valve. These patients with low-flow low-gradient or paradoxical low-flow low-gradient AS are particularly challenging to diagnose, and cardiac output and flow across the aortic valve have become the most relevant parameters in evaluation of AS, besides gradients and aortic valve area. The introduction of other imaging modalities in the diagnosis of AS significantly improved our knowledge about cardiac mechanics, tissue characterization of myocardium, calcium and inflammation burden of the aortic valve, and their impact on severity, progression and prognosis of AS, not only in symptomatic but also in asymptomatic patients. However, a variety of novel parameters also brought uncertainty regarding the clinical relevance of these indices, as well as the necessity for their validation in everyday practice. The aim of this review is to summarize the prevalence of HF in patients with severe AS and elaborate on the diagnostic challenges and advantages of comprehensive multimodality cardiac imaging to identify the patients that may benefit from surgical or transcatheter aortic valve replacement, as well as parameters that may help during follow-up.

Baseline left ventricular diastolic dysfunction affects midterm mortality after transcatheter aortic valve implantation

OBJECTIVES

To determine whether preprocedural left ventricular (LV) diastolic dysfunction impairs midterm mortality after transcatheter aortic valve implantation (TAVI) for patients with severe aortic stenosis (AS), we performed a meta-analysis of currently available evidence.

METHODS

We identified all studies investigating impact of preprocedural severity of LV diastolic dysfunction on midterm (≥1-year) all-cause mortality after TAVI for patients with AS through a search of databases (MEDLINE and EMBASE) until September 2019. From each study, we extracted an adjusted (if unavailable, unadjusted) hazard ratio (HR) of midterm mortality. We pooled study-specific estimates in the random-effects model.

RESULTS

Ten eligible studies with a total of 2380 patients with AS undergoing TAVI were identified. In accordance with pooled analyses, higher-grade preprocedural LV diastolic dysfunction was associated with significantly worse midterm all-cause mortality after TAVI compared to lower-grade dysfunction (HR for grade II vs I, 1.15; P = .002; HR for grade III vs I, 1.35; P = .001; HR for grade III vs II; 1.16, P = .002; HR for grade II-III vs I, II-III vs 0-I, or III vs I-II, 1.34; P < .00001 [primary meta-analysis]; HR per grade, 1.16; P = .003). No funnel plot asymmetry for the primary meta-analysis (for grade II-III vs I, II-III vs 0-I, or III vs I-II) was identified, which probably indicated no publication bias (P = .381 by the linear-regression test).

CONCLUSION

Higher-grade preprocedural LV diastolic dysfunction was associated with worse midterm all-cause mortality after TAVI for patients with AS compared to lower-grade dysfunction.

Outcome of patients with heart failure after transcatheter aortic valve implantation

AIMS

Patients with aortic stenosis (AS) may have concomitant heart failure (HF) that determines prognosis despite successful transcatheter aortic valve implantation (TAVI). We compared outcomes of TAVI patients with low stroke volume index (SVI) ≤35 ml/m2 body surface area in different HF classes.

METHODS AND RESULTS

Patients treated by transfemoral TAVI at our center (n = 1822) were classified as 1) 'HF with preserved ejection fraction (EF)' (HFpEF, EF ≥50%), 2) 'HF with mid-range EF' (HFmrEF, EF 40-49%), or 3) 'HF with reduced EF' (HFrEF, EF <40%). Patients with SVI >35 ml/m2 served as controls. The prevalence of cardiovascular disease and symptoms increased stepwise from controls (n = 968) to patients with HFpEF (n = 591), HFmrEF (n = 97), and HFrEF (n = 166). Mortality tended to be highest in HFrEF patients 30 days post-procedure, and it became significant after one year: 10.2% (controls), 13.5% (HFpEF), 13.4% (HFmrEF), and 23.5% (HFrEF). However, symptomatic improvement in survivors of all groups was achieved in the majority of patients without differences among groups.

CONCLUSIONS

Patients with AS and HF benefit from TAVI with respect to symptom alleviation. TAVI in patients with HFpEF and HFmrEF led to an identical, favorable post-procedural prognosis that was significantly better than that of patients with HFrEF, which remains a high-risk population.

Significance of echocardiographic evaluation for transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is widely accepted as an alternative to surgical aortic valve replacement (SAVR) for the treatment of severe aortic stenosis (AS). Existing scientific evidence demonstrates that TAVI is superior to SAVR, and it is expected that indications for the clinical applications of TAVI will be expanded in the future. Echocardiography plays a key role in perioperative assessment of patients undergoing TAVI. Preprocedural echocardiographic evaluation is important to determine the severity of AS in addition to patients' anatomical suitability for TAVI. Furthermore, echocardiography is essential for intraoperative guidance, assessment of complications, postoperative evaluation, and prognostic prediction. Inaccurate echocardiographic measurements and evaluation can lead to less-than-optimal/inappropriate treatment strategies in patients with AS. Therefore, a thorough understanding of the limitations of echocardiographic evaluation is important. This review summarizes the role of echocardiographic evaluation in patients undergoing TAVI.

Impact of baseline left ventricular ejection fraction on outcome after transfemoral transcatheter aortic valve implantation in patients with and without low-gradient aortic stenosis

OBJECTIVES

To evaluate the impact of baseline left ventricular ejection fraction (LVEF) and its interaction with low-gradient aortic stenosis (LGAS) on all-cause mortality after transfemoral aortic valve implantation (TF-TAVI).

METHODS

We reviewed mortality data of 624 consecutive single center TF-TAVI patients and categorized LVEF according to current ASE/EACVI recommendations (normal, mildly-, moderately-, and severely abnormal).

RESULTS

Baseline LVEF was normal in 336 (53.8%), mildly abnormal in 160 (25.6%), moderately abnormal in 91 (14.6%), and severely abnormal in 37 (5.9%) patients, and 1-year mortality was 19%, 17%, 23%, and 43% (P = 0.002), respectively. Patients with LGAS had a similar 1-year mortality compared to those without LGAS in groups with normal (19% vs 19%, P = 0.899) and mildly abnormal LVEF (16% vs 17%, P = 0.898). One-year mortality of patients with LGAS was significantly greater than in those without LGAS in presence of moderately abnormal LVEF (31% vs 11%, P = 0.022), and it was numerically greater than in those without LGAS in presence of severely abnormal LVEF (48% vs 25%, P = 0.219). In multivariate analysis, only the combination of moderately/severely abnormal LVEF and LGAS predicted increased 1-year mortality (HR: 2.12, 95% CI: 1.4-3.2, P < 0.001). Other variables, including EuroSCORE I did not affect this result.

CONCLUSIONS

Moderately/severely abnormal LVEF (≤40%) at baseline is associated with increased mortality after TF-TAVI, especially when the mean transvalvular aortic gradient is <40 mm Hg (LGAS), while outcomes in patients with normal and mildly abnormal LVEF are comparable regardless of the pressure gradient across the native aortic valve. (DRKS00013729).

Prognostic Significance of Change in the Left Ventricular Ejection Fraction After Transcatheter Aortic Valve Implantation in Patients With Severe Aortic Stenosis and Left Ventricular Dysfunction

Patients with severe aortic stenosis and reduced left ventricular ejection fraction (LVEF) have a poor prognosis compared with patients with preserved LVEF. To evaluate the impact of early LVEF recovery in patients with baseline dysfunction on clinical outcomes after transcatheter aortic valve implantation (TAVI), we included all consecutive patients who underwent TAVI from the Italian ClinicalService registry with an LVEF of ≤45% at baseline who had 1-month LVEF data. Patients who experienced a previous coronary artery bypass graft, a previous valve replacement, or a previous myocardial infarction were excluded from the analysis. Therefore, 131 patients with an improvement in LVEF of <10% (no-R group) were compared with 121 patients with an improvement in LVEF of ≥10% (R group). The primary end point was the rate of death of any cause. Multivariable analysis was performed to determine independent predictors of lack in LVEF recovery. Early LVEF recovery occurred in 48% of the patients, generally before discharge. One-year all-cause mortality and major adverse cardiac and cerebrovascular events were significantly higher in the no-early recovery group (log rank test p = 0.005 and p = 0.003, respectively). Baseline severe left ventricular dysfunction and previous percutaneous coronary intervention were identified as independent predictors to warn the lack of improvement in LVEF. In conclusion, nearly 50% of patients with preoperative left ventricular dysfunction demonstrated a significant early improvement in LVEF after TAVI. Lack of early LVEF recovery is associated with a worse clinical outcome and is most likely among patients with a severely abnormal baseline LVEF and a previous percutaneous coronary intervention.