Comparative Outcomes of Surgical and Transcatheter Aortic Valve Replacement: A Meta-analysis and Parametric Extrapolation of Clinical Trials

INTRODUCTION

We aimed to pool randomized clinical trials (RCTs) comparing surgical aortic valve replacement (SAVR) with transcatheter aortic valve replacement (TAVR) and extrapolate pooled time-to-event data to compare long-term outcomes.

METHODS

An electronic database search was performed for RCTs comparing SAVR with TAVR. The most current longest follow-up data for each RCT were included. Data were pooled using a random-effects model. Survival data were pooled for Kaplan-Meier analysis as well as parametric modeling with extrapolation.

RESULTS

Seven RCTs comprising 7774 patients were included. Mean valve gradient at 5 y was comparable between SAVR [11 mmHg (3.7; 18.3)] and TAVR [8.1 mmHg (1.9; 14.3)] (P = 0.38). TAVR had a higher mean valve area at 30 d, 1 y, and 2 y [1.68 cm2 (1.22; 2.13) versus 1.8 cm2 (1.35; 2.25), P = 0.02]. SAVR had a higher freedom from any paravalvular leak at 30 d and 1 y [86% (81; 90) versus 39% (36; 41), P < 0.01]. All-cause death was lower in the SAVR group at 5 y [39% (29; 50) versus 43% (31; 57), P < 0.01]. Although no differences were seen between SAVR and TAVR in the pooled Kaplan-Meier analysis of all-cause mortality and composite of all-cause mortality or stroke, parametric modeling with extrapolation showed significant divergence for both outcomes.

CONCLUSIONS

Pooled all-cause mortality as well as pooled composite of all-cause mortality or stroke indicated better survival with SAVR at 5 y. Long-term parametric extrapolation also indicated superior survival with SAVR.

Reverse left ventricular remodeling after aortic valve replacement for aortic stenosis: a systematic review and meta-analysis

Reverse left ventricular (LV) remodeling after aortic valve replacement (AVR), in patients with aortic stenosis, is well-documented as an important prognostic factor. With this systematic review and meta-analysis, we aimed to characterize the response of the unloaded LV after AVR. We searched on MEDLINE/PubMed and Web of Science for studies reporting echocardiographic findings before and at least 1 month after AVR for the treatment of aortic stenosis. In total, 1,836 studies were identified and 1,098 were screened for inclusion. The main factors of interest were structural and dynamic measures of the LV and aortic valve. We performed a random-effects meta-analysis to compute standardized mean differences (SMD) between follow-up and baseline values for each outcome. Twenty-seven studies met the eligibility criteria, yielding 11,751 patients. AVR resulted in reduced mean aortic gradient (SMD: - 38.23 mmHg, 95% CI: - 39.88 to - 36.58 , I 2 = 92 % ), LV mass (SMD: - 37.24 g, 95% CI: - 49.31 to - 25.18 , I 2 = 96 % ), end-diastolic LV diameter (SMD: - 1.78 mm, 95% CI: - 2.80 to - 0.76 , I 2 = 96 % ), end-diastolic LV volume (SMD: - 1.6 ml, 95% CI: - 6.68 to 3.51, I 2 = 91 % ), increased effective aortic valve area (SMD: 1.10 cm2, 95% CI: 1.01 to 1.20, I 2 = 98 % ), and LV ejection fraction (SMD: 2.35%, 95% CI: 1.31 to 3.40%, I 2 = 94.1 % ). Our results characterize the extent to which reverse remodeling is expected to occur after AVR. Notably, in our study, reverse remodeling was documented as soon as 1 month after AVR.

Transcatheter or surgical aortic valve implantation: 10-year outcomes of the NOTION trial

BACKGROUND AND AIMS

Transcatheter aortic valve implantation (TAVI) has become a viable treatment option for patients with severe aortic valve stenosis across a broad range of surgical risk. The Nordic Aortic Valve Intervention (NOTION) trial was the first to randomize patients at lower surgical risk to TAVI or surgical aortic valve replacement (SAVR). The aim of the present study was to report clinical and bioprosthesis outcomes after 10 years.

METHODS

The NOTION trial randomized 280 patients to TAVI with the self-expanding CoreValve (Medtronic Inc.) bioprosthesis (n = 145) or SAVR with a bioprosthesis (n = 135). The primary composite outcome was the risk of all-cause mortality, stroke, or myocardial infarction. Bioprosthetic valve dysfunction (BVD) was classified as structural valve deterioration (SVD), non-structural valve dysfunction (NSVD), clinical valve thrombosis, or endocarditis according to Valve Academic Research Consortium-3 criteria. Severe SVD was defined as (i) a transprosthetic gradient of 30 mmHg or more and an increase in transprosthetic gradient of 20 mmHg or more or (ii) severe new intraprosthetic regurgitation. Bioprosthetic valve failure (BVF) was defined as the composite rate of death from a valve-related cause or an unexplained death following the diagnosis of BVD, aortic valve re-intervention, or severe SVD.

RESULTS

Baseline characteristics were similar between TAVI and SAVR: age 79.2 ± 4.9 years and 79.0 ± 4.7 years (P = .7), male 52.6% and 53.8% (P = .8), and Society of Thoracic Surgeons score < 4% of 83.4% and 80.0% (P = .5), respectively. After 10 years, the risk of the composite outcome all-cause mortality, stroke, or myocardial infarction was 65.5% after TAVI and 65.5% after SAVR [hazard ratio (HR) 1.0; 95% confidence interval (CI) 0.7-1.3; P = .9], with no difference for each individual outcome. Severe SVD had occurred in 1.5% and 10.0% (HR 0.2; 95% CI 0.04-0.7; P = .02) after TAVI and SAVR, respectively. The cumulative incidence for severe NSVD was 20.5% and 43.0% (P < .001) and for endocarditis 7.2% and 7.4% (P = 1.0) after TAVI and SAVR, respectively. No patients had clinical valve thrombosis. Bioprosthetic valve failure occurred in 9.7% of TAVI and 13.8% of SAVR patients (HR 0.7; 95% CI 0.4-1.5; P = .4).

CONCLUSIONS

In patients with severe AS and lower surgical risk randomized to TAVI or SAVR, the risk of major clinical outcomes was not different 10 years after treatment. The risk of severe bioprosthesis SVD was lower after TAVR compared with SAVR, while the risk of BVF was similar.

Impact of Transcatheter Aortic Valve Replacement on Cardiac Reverse Remodeling and Prognosis in Mixed Aortic Valve Disease

BACKGROUND

The management of mixed aortic valve disease (MAVD), defined as the concomitant presence of aortic stenosis (AS) and aortic regurgitation, remains a clinical challenging. The present study assessed the impact of transcatheter aortic valve replacement (TAVR) on cardiac geometry and prognosis in patients with MAVD.

METHODS AND RESULTS

A retrospective multicenter TAVR registry was conducted, including patients who underwent TAVR for severe symptomatic AS between January 2015 and March 2019. Patients were subdivided into 2 groups according to concomitant presence of moderate or more severe aortic regurgitation as the MAVD group, and with mild or less severe aortic regurgitation as the isolated AS group. The primary outcome was a composite of cardiovascular death and rehospitalization due to cardiovascular causes. A total of 1742 patients (isolated AS, 1522 patients; MAVD, 220 patients) were included (84.0±5.2 years). Although MAVD exhibited significantly larger left ventricular volumes and higher left ventricular mass index at the TAVR procedure than isolated AS (respectively, P<0.001), MAVD showed a greater improvement of left ventricular volumes and left ventricular mass index after TAVR (respectively, P≤0.001). During a median follow-up of 747 days, 301 patients achieved the primary event. The prognosis post-TAVR was comparable between the 2 groups (log-rank P=0.65). Even after adjustment using propensity score matching to reduce the potential bias between the 2 groups, similar results were obtained for the entire cohort.

CONCLUSIONS

Despite more advanced cardiac remodeling in MAVD at the time of TAVR compared with isolated AS, a greater improvement of cardiac reverse remodeling was found in MAVD, and the prognosis following TAVR was comparable between the 2 groups.

Minimally Invasive Versus Transcatheter Aortic Valve Replacement: An Updated Meta-Analysis and Systematic Review

OBJECTIVE

Transcatheter aortic valve replacement (TAVR) has arisen as a viable alternative to surgery. Similarly, minimally invasive surgical aortic valve replacement (mini-SAVR), such as ministernotomy and minithoracotomy, have also gained interest. We conducted a pairwise meta-analysis to further investigate the efficacy of TAVR versus mini-SAVR.

METHODS

Medical databases were comprehensively searched for studies comparing TAVR with a mini-SAVR modality, defined as minimally invasive aortic surgery, ministernotomy, minithoracotomy, or rapid-deployment or sutureless SAVR. Random-effects meta-analysis was conducted using the generic inverse variance method. Primary outcomes included 30-day mortality, midterm mortality, 30-day stroke, acute kidney injury (AKI), paravalvular leak (PVL), new permanent pacemaker (PPM), new-onset atrial fibrillation, and postintervention mean and peak valve pressure gradients and were pooled as risk ratio (RR), mean difference (MD), or hazard ratio (HR) with 95% confidence interval (CI).

RESULTS

A total of 5,071 patients (2,505 mini-SAVR vs 2,566 TAVR) from 12 studies were pooled. Compared with TAVR, mini-SAVR showed significantly lower rates of both 30-day (RR = 0.63, 95% CI: 0.42 to 0.96, P = 0.03) and midterm mortality at 4 years of follow-up (HR = 0.76, 95% CI: 0.67 to 0.87, P < 0.001). Furthermore, mini-SAVR was protective against 30-day PVL (RR = 0.07, 95% CI: 0.04 to 0.13, P < 0.001) and new PPM (RR = 0.25, 95% CI: 0.11 to 0.57, P < 0.001). Conversely, TAVR was protective against 30-day AKI (RR = 1.67, 95% CI: 1.20 to 2.32, P = 0.002) and postinterventional mean gradients (MD = 1.65, 95% CI: 0.25 to 3.05, P = 0.02). No difference was observed for 30-day stroke (RR = 0.84, 95% CI: 0.56 to 1.24, P = 0.38), new-onset atrial fibrillation (RR = 1.79, 95% CI: 0.93 to 3.44, P = 0.08), or postinterventional peak gradients (MD = 3.24, 95% CI: -1.10 to 7.59, P = 0.14).

CONCLUSIONS

Compared with TAVR, mini-SAVR was protective against 30-day and midterm mortality, 30-day PVL, and new permanent pacemaker, while TAVR patients had lower 30-day AKI. Future randomized trials comparing the efficacy of mini-SAVR approaches with TAVR are needed.

Interaction between sex and left ventricular reverse remodeling and its association with outcomes after transcatheter aortic valve implantation

Women with severe aortic stenosis (AS) have better long-term prognosis after transcatheter aortic valve implantation (TAVI) compared to men. Whether this is caused by sex-related differences in left ventricular (LV) reverse remodeling after TAVI is unknown. Patients with severe AS who underwent transfemoral TAVI between 2007 and 2018 were selected. LV dimensions, volumes, and ejection fraction (LVEF) were assessed by transthoracic echocardiography before TAVI and at 6 and 12 months follow-up after TAVI. LV reverse remodeling was defined as the percentual LV mass index (LVMi) reduction compared to baseline. The primary outcome was all-cause mortality. A total of 459 patients (80 ± 8 years; 52% male) were included. At 6 and 12 months follow-up, both sexes showed significant reductions in LV volumes and LVMi accompanied by improvement in LVEF, without significant differences between the sexes over time. During a median follow-up of 2.8 [IQR 1.9-4.3] years, 181 (39%) patients died. Women showed better outcomes compared to men (log-rank p = 0.024). In addition, male sex was independently associated with all-cause mortality in multivariable Cox regression (HR 1.423, 95% CI 1.039-1.951, p = 0.028). No association was observed between the interaction of percentual LVMi reduction and sex with outcomes (p = 0.64). Men and women with severe AS had similar improvement in LVEF, and similar reductions in LV volumes and LVMi at 6 and 12 months after TAVI. Women showed better survival after TAVI as compared to men. The superior outcomes noted in women after TAVI are not associated with sex differences in LV reverse remodeling.

Prognostic Implications of Change in Left Ventricular Ejection Fraction After Transcatheter Aortic Valve Implantation

Reduced left ventricular (LV) systolic function is associated with worse prognosis in patients with severe aortic stenosis (AS) treated with transcatheter aortic valve implantation (TAVI). We aimed to examine the changes in left ventricular ejection fraction (LVEF) after TAVI among patients with varying baseline LVEF. Moreover, variables associated with lack of LVEF improvement were identified and the association with long-term outcomes was investigated. A total of 560 patients (age 80 ± 7 years, 53% men) with severe AS who underwent transfemoral TAVI between 2007 and 2019 were selected. LVEF was assessed from transthoracic echocardiography at baseline (before TAVI) and at 6 and 12 months after TAVI. Patients were stratified according to baseline LVEF: (1) LVEF ≥50%, (2) LVEF 40% to 49%, and (3) LVEF <40%. The clinical end point was ≥5% LVEF improvement. The primary outcome was all-cause mortality. Patients with baseline LVEF<40% showed greater increase in LVEF than those with baseline LVEF 40% to 49% and LVEF ≥50% (from 33% ± 6% to 43% ± 10%, p <0.001; from 45% ± 3% to 52% ± 8%, p <0.001; and from 58% ± 5% to 59% ± 7%, p = 0.012, respectively, p for interaction <0.001). Coronary artery disease (odds ratio [OR] 1.80 [95% confidence interval (CI) 1.06 to 3.06], p = 0.031), myocardial infarction (OR 2.07 [95% CI 1.19 to 3.61], p = 0.010), and permanent pacemaker (OR: 1.93 [95% CI 1.25 to 3.00], p = 0.003) were independently associated with the lack of ≥5% LVEF improvement. During a median follow-up of 3.8 (interquartile range 2.6 to 5.2) years, 176 patients died (31%). Patients with ≥5% LVEF improvement had similar outcomes compared with those with <5% LVEF improvement (log-rank p = 0.89). In conclusion, patients with severe AS and baseline LVEF <40% had the greatest improvement in LVEF at 1-year follow-up after TAVI. Coronary artery disease, myocardial infarction, and permanent pacemaker were associated with lack of LVEF improvement. However, LVEF improvement at 12 months was not associated with long-term outcomes.

Cardiac sympathetic dysfunction in left ventricular hypertrophy caused by arterial hypertension and degenerative aortic stenosis

BACKGROUND

To evaluate cardiac sympathetic innervation in hypertensive patients with left ventricular (LV) hypertrophy (H) and aortic stenosis (AS) submitted to transcatheter aortic valve implantation (TAVI).

METHODS AND RESULTS

Twenty-two hypertensive elders (82 ± 5 years) with severe AS and significant LVH (> 122 g·m-2 in women and > 149 g·m-2 in men) were compared with 14 patients with uncomplicated essential hypertension (HT) with similar degree of LVH and 10 controls. 123I-metaiodobenzylguanidine (MIBG) and 99mTc-tetrofosmin SPECT acquisitions were obtained to assess sympathetic innervation and LV perfusion. The innervation/perfusion mismatch score was taken as an indicator of cardiac sympathetic dysfunction. The imaging protocol was repeated 6 months after TAVI. Regional MIBG uptake was more heterogeneous in HT and AS patients than controls, and therefore, innervation/perfusion mismatch score was higher in both AS (9 ± 8) and HT (5 ± 2) than controls (1 ± 1, P < .001). On multivariate analysis, significant LVH was the major predictor of impaired LV sympathetic innervation (OR 19.45, 95% CI 1.87-201.92; P = .013). After TAVI, no differences in measures of LV sympathetic innervation were evident, although only a marginal LV mass reduction was observed (- 5.4 ± 2.4 g).

CONCLUSIONS

Cardiac sympathetic innervation is impaired in patients with LVH, either with AS or not, and is not impacted significantly by TAVI procedure.

Transcatheter aortic valve implantation versus surgical aortic valve replacement in patients with severe aortic stenosis: a systematic review and meta-analysis

OBJECTIVES

Patients undergoing surgery for severe aortic stenosis (SAS) can be treated with either transcatheter aortic valve implantation (TAVI) or surgical aortic valve replacement (SAVR). The choice of procedure depends on several factors, including the clinical judgement of the heart team and patient preferences, which are captured by actively informing and involving patients in a process of shared decision making (SDM). We synthesised the most up-to-date and accessible evidence on the benefits and risks that may be associated with TAVI versus SAVR to support SDM in this highly personalised decision-making process.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE (Ovid), Embase (Ovid) and the Cochrane Central Register of Controlled Trials (CENTRAL; Wiley) were searched from January 2000 to August 2020 with no language restrictions. Reference lists of included studies were searched to identify additional studies.

ELIGIBILITY CRITERIA

Randomised controlled trials (RCTs) that compared TAVI versus SAVR in patients with SAS and reported on all-cause or cardiovascular mortality, length of stay in intensive care unit or hospital, valve durability, rehospitalisation/reintervention, stroke (any stroke or major/disabling stroke), myocardial infarction, major vascular complications, major bleeding, permanent pacemaker (PPM) implantation, new-onset or worsening atrial fibrillation (NOW-AF), endocarditis, acute kidney injury (AKI), recovery time or pain were included.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers were involved in data extraction and risk of bias (ROB) assessment using the Cochrane tool (one reviewer extracted/assessed the data, and the second reviewer checked it). Dichotomous data were pooled using the Mantel-Haenszel method with random-effects to generate a risk ratio (RR) with 95% CI. Continuous data were pooled using the inverse-variance method with random-effects and expressed as a mean difference (MD) with 95% CI. Heterogeneity was assessed using the I² statistic.

RESULTS

8969 records were retrieved and nine RCTs (61 records) were ultimately included (n=8818 participants). Two RCTs recruited high-risk patients, two RCTs recruited intermediate-risk patients, two RCTs recruited low-risk patients, one RCT recruited high-risk (≥70 years) or any-risk (≥80 years) patients; and two RCTs recruited all-risk or 'operable' patients. While there was no overall change in the risk of dying from any cause (30 day: RR 0.89, 95% CI 0.65 to 1.22; ≤1 year: RR 0.90, 95% CI 0.79 to 1.03; 5 years: RR 1.09, 95% CI 0.98 to 1.22), cardiovascular mortality (30 day: RR 1.03, 95% CI 0.77 to 1.39; ≤1 year: RR 0.90, 95% CI 0.76 to 1.06; 2 years: RR 0.96, 95% CI 0.83 to 1.12), or any type of stroke (30 day: RR 0.83, 95% CI 0.61 to 1.14;≤1 year: RR 0.94, 95% CI 0.72 to 1.23; 5 years: RR 1.07, 95% CI 0.88 to 1.30), the risk of several clinical outcomes was significantly decreased (major bleeding, AKI, NOW-AF) or significantly increased (major vascular complications, PPM implantation) for TAVI vs SAVR. TAVI was associated with a significantly shorter hospital stay vs SAVR (MD -3.08 days, 95% CI -4.86 to -1.29; 4 RCTs, n=2758 participants). Subgroup analysis generally favoured TAVI patients receiving implantation via the transfemoral (TF) route (vs non-TF); receiving a balloon-expandable (vs self-expanding) valve; and those at low-intermediate risk (vs high risk). All RCTs were rated at high ROB, predominantly due to lack of blinding and selective reporting.

CONCLUSIONS

No overall change in the risk of death from any cause or cardiovascular mortality was identified but 95% CIs were often wide, indicating uncertainty. TAVI may reduce the risk of certain side effects while SAVR may reduce the risk of others. Most long-term (5-year) results are limited to older patients at high surgical risk (ie, early trials), therefore more data are required for low risk populations. Ultimately, neither surgical technique was considered dominant, and these results suggest that every patient with SAS should be individually engaged in SDM to make evidence-based, personalised decisions around their care based on the various benefits and risks associated with each treatment.

PROSPERO REGISTRATION NUMBER

CRD42019138171.

The coronary and microcirculatory measurements in patients with aortic valve stenosis study: rationale and design

Although concomitant coronary artery disease (CAD) is frequent in patients with severe aortic stenosis (AS), hemodynamic assessment of CAD severity in patients undergoing valve replacement for severe AS is challenging. Myocardial hypertrophic remodeling interferes with coronary blood flow and may influence the values of fractional flow reserve (FFR) and nonhyperemic pressure ratios (NHPRs). The aim of the current study is to investigate the effect of the AS and its treatment on current indices used for evaluation of CAD. We will compare intracoronary hemodynamics before, immediately after, and 6 mo after aortic valve replacement (AVR) when it is expected that microvascular function has improved. Furthermore, we will compare FFR and resting full-cycle ratio (RFR) with myocardial perfusion single-photon emission-computed tomography (SPECT) as indicators of myocardial ischemia in patients with AS and CAD. One-hundred consecutive patients with AS and intermediate CAD will be prospectively included. Patients will undergo pre-AVR SPECT and intracoronary hemodynamic assessment at baseline, immediately after valve replacement [if transcatheter AVR (TAVR) is chosen], and 6 mo after AVR. The primary end point is the change in FFR 6 mo after AVR. Secondary end points include the acute change of FFR after TAVR, the diagnostic accuracy of FFR versus RFR compared with SPECT for the assessment of ischemia, changes in microvascular function as assessed by the index of microcirculatory resistance (IMR), and the effect of these changes on FFR. The present study will evaluate intracoronary hemodynamic parameters before, immediately after, and 6 mo after AVR in patients with AS and intermediate coronary stenosis. The understanding of the impact of AVR on the assessment of FFR, NHPR, and microvascular function may help guide the need for revascularization in patients with AS and CAD planned for AVR.

Impact of conduction disturbances on left ventricular mass regression and geometry change following transcatheter aortic valve replacement

Our study aimed to compare the difference of LV mass regression and remodeling in regard of conduction disturbances (CD) following transcatheter aortic valve replacement (TAVR). A prospective analysis of 152 consecutive TAVR patients was performed. 53 patients (34.9%) had CD following TAVR, including 30 (19.7%) permanent pacemaker implantation and 23 (15.2%) new left bundle branch block. In 123 patients with 1-year follow-up, significant improvement of LV ejection fraction (LVEF) (baseline vs 12-month: 65.1 ± 13.2 vs 68.7 ± 9.1, P = 0.017) and reduced LV end-systolic volume (LVESV) (39.8 ± 25.8 vs 34.3 ± 17.1, P = 0.011) was found in non-CD group (N = 85), but not in CD group (N = 38). Both groups had significant decrease in LV mass index (baseline vs 12-month: 148.6 ± 36.9 vs. 136.4 ± 34.7 in CD group, p = 0.023; 153.0 ± 50.5 vs. 125.6 ± 35.1 in non-CD group, p < 0.0001). In 46 patients with 3-year follow-up, only non-CD patients (N = 28) had statistically significant decrease in LV mass index (Baseline vs 36-month: 180.8 ± 58.8 vs 129.8 ± 39.1, p = 0.0001). Our study showed the improvement of LV systolic function, reduced LVESV and LV mass regression at 1 year could be observed in patients without CD after TAVR. Sustained LV mass regression within 3-year was found only in patients without CD.

Left Ventricle Mass Regression After Surgical or Transcatheter Aortic Valve Replacement in Veterans

BACKGROUND

Differences in left ventricular mass regression (LVMR) between transcatheter aortic valve replacement (TAVR) and surgical aortic valve replacement (SAVR) have not been studied. We present clinical and echocardiographic data from veterans who underwent TAVR and SAVR, evaluating the degree of LVMR and its association with survival.

METHODS

We retrospectively reviewed TAVR (n = 194) and SAVR (n = 365) procedures performed in veterans from 2011 to 2019. After 1:1 propensity matching, we evaluated mortality and secondary outcomes. Echocardiographic data (median follow-up 957 days, interquartile range 483-1652 days) were used to evaluate LVMR, its association with survival, and predictors of LVMR.

RESULTS

There was no difference between SAVR and TAVR patients in mortality (for up to 8 years), stroke at 30 days, myocardial infarction, renal failure, prolonged ventilation, reoperation, or structural valve deterioration. SAVR patients (67.3% [101 of 150]) were more likely to have LVMR than TAVR patients (55.7% [44 of 79], P = .11). The magnitude of LVMR was greater for the SAVR patients (median, -23.3%) than for the TAVR patients (median, -17.8%, P = .062). SAVR patients with LVMR had a survival advantage over SAVR patients without LVMR (P = .016). However, LVMR was not associated with greater survival in TAVR patients (P = .248).

CONCLUSIONS

SAVR patients were more likely to have LVMR and had a greater magnitude of LVMR than TAVR patients. LVMR was associated with better survival in SAVR patients, but not in TAVR patients.

Challenges and opportunities in improving left ventricular remodelling and clinical outcome following surgical and trans-catheter aortic valve replacement

Over the last half century, surgical aortic valve replacement (SAVR) has evolved to offer a durable and efficient valve haemodynamically, with low procedural complications that allows favourable remodelling of left ventricular (LV) structure and function. The latter has become more challenging among elderly patients, particularly following trans-catheter aortic valve implantation (TAVI). Precise understanding of myocardial adaptation to pressure and volume overloading and its responses to valve surgery requires comprehensive assessments from aortic valve energy loss, valvular-vascular impedance to myocardial activation, force-velocity relationship, and myocardial strain. LV hypertrophy and myocardial fibrosis remains as the structural and morphological focus in this endeavour. Early intervention in asymptomatic aortic stenosis or regurgitation along with individualised management of hypertension and atrial fibrillation is likely to improve patient outcome. Physiological pacing via the His-Purkinje system for conduction abnormalities, further reduction in para-valvular aortic regurgitation along with therapy of angiotensin receptor blockade will improve patient outcome by facilitating hypertrophy regression, LV coordinate contraction, and global vascular function. TAVI leaflet thromboses require anticoagulation while impaired access to coronary ostia risks future TAVI-in-TAVI or coronary interventions. Until comparable long-term durability and the resolution of TAVI related complications become available, SAVR remains the first choice for lower risk younger patients.

Electrocardiographic Strain Pattern Is a Major Determinant of Rehospitalization for Heart Failure After Transcatheter Aortic Valve Replacement

Background Electrocardiographic strain pattern (ESP) has recently been associated with increased adverse outcome in aortic stenosis and after surgical aortic valve replacement. Our study sought to determine the impact and incremental value of ESP pattern in predicting adverse outcome after transcatheter aortic valve replacement. Methods and Results A total of 585 patients with severe aortic stenosis (mean age, 83±7 years; men, 39.8%) were enrolled for transcatheter aortic valve replacement from November 2012 to May 2018. ESP was defined as ≥1-mm concave down-sloping ST-segment depression and asymmetrical T-wave inversion in the lateral leads. The primary end points of the study were all-cause mortality, rehospitalization for heart failure, myocardial infarction, and stroke. A total of 178 (30.4%) patients were excluded because of left bundle-branch block (n=103) or right bundle-branch block (n=75). Among the 407 remaining patients, 106 had ESP (26.04%). At a median follow-up of 20.00 months (11.70-29.42 months), no impact of electric strain on overall and cardiac death could be established. By contrast, incidence of rehospitalization for heart failure was significantly higher (33/106 [31.1%] versus 33/301 [11%]; P<0.001) in patients with ESP. By multivariate analyses, ESP remained a strong predictor of rehospitalization for heart failure (hazard ratio, 2.75 [95% CI, 1.61-4.67]; P<0.001). Conclusions In patients with aortic stenosis who were eligible for transcatheter aortic valve replacement, ESP is frequent and associated with an increased risk of postinterventional heart failure regardless of preoperative left ventricular hypertrophy. ESP represents an easy, objective, reliable, and low-cost tool to identify patients who may benefit from intensified postinterventional follow-up.

Time course of left ventricular remodelling and mechanics after aortic valve surgery: aortic stenosis vs. aortic regurgitation

Aims

Pressure overload in aortic stenosis (AS) and both pressure and volume overload in aortic regurgitation (AR) induce concentric and eccentric hypertrophy, respectively. These structural changes influence left ventricular (LV) mechanics, but little is known about the time course of LV remodelling and mechanics after aortic valve surgery (AVR) and its differences in AS vs. AR. The present study aimed to characterize the time course of LV mass index (LVMI) and LV mechanics [by LV global longitudinal strain (LV GLS)] after AVR in AS vs. AR.

Methods and results

Two hundred and eleven (61 ± 14 years, 61% male) patients with severe AS (63%) or AR (37%) undergoing surgical AVR with routine echocardiographic follow-up at 1, 2, and/or 5 years were evaluated. Before AVR, LVMI was larger in AR patients compared with AS. Both groups showed moderately impaired LV GLS, but preserved LV ejection fraction. After surgery, both groups showed LV mass regression, although a more pronounced decline was seen in AR patients. Improvement in LV GLS was observed in both groups, but characterized by an initial decline in AR patients while LV GLS in AS patients remained initially stable.

Conclusion

In severe AS and AR patients undergoing AVR, LV mass regression and changes in LV GLS are similar despite different LV remodelling before AVR. In AR, relief of volume overload led to reduction in LVMI and an initial decline in LV GLS. In contrast, relief of pressure overload in AS was characterized by a stable LV GLS and more sustained LV mass regression.

Network Meta-analysis of Surgical Aortic Valve Replacement and Different Transcatheter Heart Valve Systems for Symptomatic Severe Aortic Stenosis

BACKGROUND

Although different transcatheter heart valve (THV) systems have been introduced to overcome transcatheter aortic valve replacement (TAVR)-specific complications, head-to-head comparisons of these THV systems are scarce. The aim of this study was to compare different THV systems and surgical aortic valve replacement (SAVR) by conducting a network meta-analysis.

METHODS

PubMed and EMBASE were searched through November 2019 for studies comparing safety and efficacy of balloon-expandable valve (BEV), self-expanding valve (SEV), mechanically expandable valve (MEV), and SAVR for symptomatic severe aortic stenosis. End points in the short term at 30 days or discharge and the long term up to 2 years were assessed.

RESULTS

We identified 11 randomized controlled trials with a total of 10,300 patients eligible for inclusion in our study. There were no significant differences in all-cause death among different THV systems and SAVR in both short and long terms. Disabling stroke was significantly lower with MEV vs BEV and SAVR (hazard ratios [HRs] 0.31 [95% confidence interval [CI] 0.12-0.77] and 0.33 [95% CI 0.14-0.76], respectively) in the long term. MEV was associated with an increased risk of new permanent pacemaker implantation compared with BEV, SEV, and SAVR (HRs 3.82 [95% CI 1.83-7.97], 1.85 [95% CI 1.02-3.36], and 5.23 [95% CI 2.61-10.47], respectively) in the long term.

CONCLUSIONS

In patients with symptomatic severe aortic stenosis undergoing intervention, there were no significant differences in all-cause death among different THV systems and SAVR. MEV had low frequency of disabling stroke compared with BEV and SAVR, but an increased frequency of permanent pacemaker implantation compared with other interventions.

Postimplant biological aortic prosthesis degeneration: challenges in transcatheter valve implants

Surgical aortic valve replacement (SAVR) is highly effective and can be achieved with relatively low risk in patients with severe aortic stenosis. Bioprostheses have been used most frequently during the past 60 years. However, the function of biological valves usually declines after 10-15 years from implant when structural valve degeneration occurs often mandating a reoperation once valve dysfunction becomes haemodynamically significant. Known for many years by surgeons and cardiologists taking care of patients with SAVR, the issue of postimplant structural valve degeneration has been recently highlighted also in patients with transcatheter aortic valve implant (TAVI). There is growing concern that TAVI valves exhibit structural valve degeneration due to inherent challenges of the deployment mode. The impact on postimplant degeneration of TAVI valves compared to SAVR has still to be understood and defined. Based on the ongoing process of expanding TAVI indications, several potential shortcomings and caveats, learned during the last 60 years of SAVR experience, should be taken into consideration to refine this technique.

Five-Year Clinical and Echocardiographic Outcomes From the NOTION Randomized Clinical Trial in Patients at Lower Surgical Risk

BACKGROUND

The NOTION trial (Nordic Aortic Valve Intervention) was designed to compare transcatheter aortic valve replacement (TAVR) with surgical aortic valve replacement (SAVR) in patients ≥70 years old with isolated severe aortic valve stenosis. Clinical and echocardiographic outcomes are presented after 5 years.

METHODS

Patients were enrolled at 3 Nordic centers and randomized 1:1 to TAVR using the self-expanding CoreValve prosthesis (n=145) or SAVR using any stented bioprostheses (n=135). The primary composite outcome was the rate of all-cause mortality, stroke, or myocardial infarction at 1 year defined according to Valve Academic Research Consortium-2 criteria.

RESULTS

Baseline characteristics were similar. The mean age was 79.1±4.8 years and mean Society of Thoracic Surgeons Predicted Risk of Mortality score was 3.0%±1.7%. After 5 years, there were no differences between TAVR and SAVR in the composite outcome (Kaplan-Meier estimates 38.0% versus 36.3%, log-rank test P=0.86) or any of its components. TAVR patients had larger prosthetic valve area (1.7 cm2 versus 1.2 cm2, P<0.001) with a lower mean transprosthetic gradient (8.2 mm Hg versus 13.7 mm Hg, P<0.001), both unchanged over time. More TAVR patients had moderate/severe total aortic regurgitation (8.2% versus 0.0%, P<0.001) and a new pacemaker (43.7% versus 8.7%, P<0.001). Four patients had prosthetic reintervention and no difference was found for functional outcomes.

CONCLUSIONS

These are currently the longest follow-up data comparing TAVR and SAVR in lower risk patients, demonstrating no statistical difference for major clinical outcomes 5 years after TAVR with a self-expanding prosthesis compared to SAVR. Higher rates of prosthetic regurgitation and pacemaker implantation were seen after TAVR.

CLINICAL TRIAL REGISTRATION

URL: https://clinicaltrials.gov. Unique identifier: NCT01057173.

Impact of Metabolic Syndrome and/or Diabetes Mellitus on Left Ventricular Mass and Remodeling in Patients With Aortic Stenosis Before and After Aortic Valve Replacement

In aortic stenosis (AS), metabolic syndrome (MetS), and diabetes mellitus (DM) are associated with more pronounced left ventricular (LV) hypertrophy and more concentric remodeling. We aimed to assess the impact of MetS and DM on LV mass, remodeling, and LV mass regression after aortic valve replacement (AVR) in patients with severe AS. We included 177 patients with severe AS and preserved LV ejection fraction (>50%). All patients underwent a complete echocardiogram before and 1 year after AVR. Forty-seven (27%) patients had MetS, 37 (21%) DM, and 93 (52%) neither MetS nor DM (No MetS-DM). Before AVR, indexed LV mass was higher in MetS and DM groups compared with No MetS-DM group (56.1 ± 14.2, 56.2 ± 18.2 vs 49.2 ± 14.1 g/m^2.7, respectively; p <0.01). Prevalence of LV hypertrophy was higher in MetS and DM than in No MetS-DM patients (66%, 65% vs 44%, p <0.01) as well as LV mass to end-diastolic volume ratio (2.10 ± 0.44 and 2.21 ± 0.63 vs 1.96 ± 0.41 g/ml, respectively, p = 0.03). After multivariate analysis, DM and MetS were independently associated with higher baseline LV mass (p <0.05). One year after AVR, decrease in LV mass was significant (p <0.001) in all 3 groups. MetS was independently associated with less LV mass regression and higher LV mass 1 year after AVR. Therefore, MetS and DM patients showed more residual LV hypertrophy than those with No MetS-DM (57%, 38%, and 17%, p <0.01). In conclusion, MetS and DM were associated with higher preoperative LV mass, more LV hypertrophy, and more concentric remodeling. One year after AVR, MetS showed less significant LV mass regression and both DM and MetS persisted with more residual LV hypertrophy.

Surgical as Opposed to Transcatheter Aortic Valve Replacement Improves Basal Interventricular Septal Hypertrophy

BACKGROUND

Basal interventricular septum (IVS) hypertrophy (BSH) with reduced basal IVS contraction and IVS-aorta angle is frequently associated with aortic stenosis (AS). BSH shape suggests compression by the longitudinally elongated ascending aorta, causing basal IVS thickening and contractile dysfunction, further suggesting the possibility of aortic wall shortening to improve the BSH. Surgical aortic valve replacement (SAVR), as opposed to transcatheter AVR (TAVR), includes aortic wall shortening by incision and stitching on the wall and may potentially improve BSH. We hypothesized that BSH configuration and its contraction improves after SAVR in patients with AS. Methods and Results: In 32 patients with SAVR and 36 with TAVR for AS, regional wall thickness and systolic contraction (longitudinal strain) of 18 left ventricular (LV) segments, and IVS-aorta angle were measured on echocardiography. After SAVR, basal IVS/average LV wall thickness ratio, basal IVS strain, and IVS-aorta angle significantly improved (1.11±0.24 to 1.06±0.17; -6.2±5.7 to -9.1±5.2%; 115±22 to 123±14°, P<0.001, respectively). Contractile improvement in basal IVS was correlated with pre-SAVR BSH (basal IVS/average LV wall thickness ratio or IVS-aorta angle: r=0.47 and 0.49, P<0.01, respectively). In contrast, BSH indices did not improve after TAVR.

CONCLUSIONS

In patients with AS, SAVR as opposed to TAVR improves associated BSH and its functional impairment.