Impact of valve prosthesis-patient mismatch on short-term mortality after aortic valve replacement

Sex Differences in Aortic Stenosis: From the Pathophysiology to the Intervention, Current Challenges, and Future Perspectives

Calcific aortic stenosis (AS) is a major cause of morbidity and mortality in high-income countries. AS presents sex-specific features impacting pathophysiology, outcomes, and management strategies. In women, AS often manifests with a high valvular fibrotic burden, small valvular annuli, concentric left ventricular (LV) remodeling/hypertrophy, and, frequently, supernormal LV ejection fraction coupled with diastolic dysfunction. Paradoxical low-flow low-gradient AS epitomizes these traits, posing significant challenges post-aortic valve replacement due to limited positive remodeling and significant risk of patient-prosthesis mismatch. Conversely, men present more commonly with LV dilatation and dysfunction, indicating the phenotype of classical low-flow low-gradient AS, i.e., with decreased LV ejection fraction. However, these distinctions have not been fully incorporated into guidelines for AS management. The only treatment for AS is aortic valve replacement; women are frequently referred late, leading to increased heart damage caused by AS. Therefore, it is important to reassess surgical planning and timing to minimize irreversible cardiac damage in women. The integrity and the consideration of sex differences in the management of AS is critical. Further research, including sufficient representation of women, is needed to investigate these differences and to develop individualized, sex-specific management strategies.

Late clinical and echocardiographic results with the Magna Ease© pericardial aortic bioprosthesis

OBJECTIVES

The population of candidates to surgical aortic valve replacement (SAVR) is evolving. The Perimount Magna Ease© bioprosthesis has been introduced relatively recently in the practice. We aimed at evaluating its long-term results.

METHODS

This article describes a single-centre cohort of 1016 consecutive SAVRs with the Magna Ease© valve (2008-2014), consisting of an all-comers population. We performed a prospective collection of in-hospital data, systematic clinical and echocardiographic follow-up. Valve-related events were as follows: structural valve deterioration (SVD; according to modified definition criteria), nonstructural valve dysfunction, patient-prosthesis mismatch (PPM).

RESULTS

Age at SAVR was 73.4 ± 9.5 years; calcified aortic stenosis was the indication to surgery in 59.6%. A total of 974 patients entered the follow-up; 564 were alive at the last follow-up (median duration: 9.8 years) (up to 13.4 years). New York Heart Association class was I or II in 92.1%. Overall survival at 10 years was 56.8 ± 1.8%. Freedom from SVD at 10 was 96.5 ± 0.8% (Kaplan-Meier) and 97.4 ± 0.6% (competing risks) (28 SVD events after 6.9 ± 3.3 years). There were 15 reinterventions for SVD (redo-SAVR and Transcatheter Aortic Valve Implantation (TAVI)); 10-year freedom from reintervention was 97.8 ± 0.6%. Moderate and severe PPM occurred in 26.8% and 5.4%, respectively, without association with late mortality (P = 0.12 for moderate and P = 0.70 for severe PPM). Freedom from valve-related mortality was 97.8 ± 0.5% at 10 years.

CONCLUSIONS

In this follow-up of the Magna Ease bioprosthesis for SAVR, data indicate good late outcomes (30-day outcomes are excluded). Continued follow-up is required to further support its use in patients with life expectancy >10-12 years.

Guidelines for the Evaluation of Prosthetic Valve Function With Cardiovascular Imaging: A Report From the American Society of Echocardiography Developed in Collaboration With the Society for Cardiovascular Magnetic Resonance and the Society of Cardiovascular Computed Tomography

In patients with significant cardiac valvular disease, intervention with either valve repair or valve replacement may be inevitable. Although valve repair is frequently performed, especially for mitral and tricuspid regurgitation, valve replacement remains common, particularly in adults. Diagnostic methods are often needed to assess the function of the prosthesis. Echocardiography is the first-line method for noninvasive evaluation of prosthetic valve function. The transthoracic approach is complemented with two-dimensional and three-dimensional transesophageal echocardiography for further refinement of valve morphology and function when needed. More recently, advances in computed tomography and cardiac magnetic resonance have enhanced their roles in evaluating valvular heart disease. This document offers a review of the echocardiographic techniques used and provides recommendations and general guidelines for evaluation of prosthetic valve function on the basis of the scientific literature and consensus of a panel of experts. This guideline discusses the role of advanced imaging with transesophageal echocardiography, cardiac computed tomography, and cardiac magnetic resonance in evaluating prosthetic valve structure, function, and regurgitation. It replaces the 2009 American Society of Echocardiography guideline on prosthetic valves and complements the 2019 guideline on the evaluation of valvular regurgitation after percutaneous valve repair or replacement.

Prosthesis-patient mismatch after transcatheter implantation of contemporary balloon-expandable and self-expandable valves in small aortic annuli

BACKGROUND

Evidence of clinical impact of PPM after TAVI is conflicting and might vary according to the type of valve implanted.

AIMS

To assess the clinical impact of prosthesis-patient mismatch (PPM) after transcatheter aortic valve implantation (TAVI) with balloon-expandable (BEV) and self-expandable valves (SEV) in patients with small annuli.

METHODS

TAVI-SMALL 2 enrolled 628 patients in an international retrospective registry, which included patients with severe aortic stenosis and small annuli (annular perimeter <72 mm or area <400 mm2 ) treated with transfemoral TAVI at 16 high-volume centers between 2011 and 2020. Analyses were performed comparing patients with less than moderate (n = 452), moderate (n = 138), and severe PPM (n = 38). Primary endpoint was incidence of all-cause mortality. Predictors of all-cause mortality and PPM were investigated.

RESULTS

At a median follow-up of 380 days (interquartile range: 210-709 days), patients with severe PPM, but not moderate PPM, had an increased risk of all-cause mortality when compared with less than moderate PPM (log-rank p = 0.046). Severe PPM predicted all-cause mortality in patients with BEV (hazard ratio [HR]: 5.20, 95% confidence interval [CI]: 1.27-21.2) and intra-annular valves (IAVs, HR: 4.23, 95% CI: 1.28-14.02), and it did so with borderline significance in the overall population (HR: 2.89, 95% CI: 0.95-8.79). Supra-annular valve (SAV) implantation was the only predictor of severe PPM (odds ratio: 0.33, 95% CI: 0.13-0.83).

CONCLUSIONS

Patients with small aortic annuli and severe PPM after TAVI have an increased risk of all-cause mortality at early term follow-up, especially after IAV or BEV implantation. TAVI with SAV protected from severe PPM.

Clinical Impact of Patient-Prosthesis Mismatch After Aortic Valve Replacement With a Mechanical or Biological Prosthesis

BACKGROUND

Patient-prosthesis mismatch (PPM) may impair functional capacity and survival after aortic valve replacement. This study aimed to investigate the impact of PPM on long-term survival and quality of life after mechanical and biological aortic valve replacement.

METHODS

This study included 595 consecutive patients who had undergone isolated aortic valve replacement. Patients were divided into 2 groups according to prosthesis type. The baseline and operative characteristics, survival rates, complications, and quality of life of the groups with and without PPM were compared for up to 6 years. The PPM calculation was performed using the effective orifice area value provided by the manufacturer divided by the patient's body surface area.

RESULTS

The moderate to severe PPM rates were 69.8% and 3.7% after biological and mechanical prosthesis implantation, respectively. Mean survival for patients in the biological group who had PPM was statistically significantly shorter (50.2 months [95% CI, 45.2-55.3]) than for patients in the biological group without PPM (60.1 months [95% CI, 55.7-64.4]; P = .04). In the mechanical prosthesis group, there was no difference in mean survival between the subgroup with PPM (66.6 months [95% CI, 58.3-74.9]) and the subgroup without PPM (64.9 months [95% CI, 62.6-67.2]; P = .50). A quality-of-life questionnaire's scores did not differ between the groups.

CONCLUSION

Mismatch is common after biological valve implantation and statistically significantly affects long-term survival and quality of life. If the risk of PPM after implantation of a biological prosthesis is suspected, adopting strategies to avoid PPM at the time of surgery is warranted.

Prosthesis-Patient Mismatch and Aortic Root Enlargement: Indications, Techniques and Outcomes

Prosthesis-patient mismatch (PPM) is defined as implanting a prosthetic that is insufficiently sized for the patient receiving it. PPM leads to high residual transvalvular gradients post-aortic valve replacement and consequently results in left ventricular dysfunction, morbidity and mortality in both the short and long term. Younger patients and patients with poor preoperative left ventricular function are more vulnerable to increased mortality secondary to PPM. There is debate over the measurement of valvular effective orifice area (EOA) and variation exists in how manufacturers report the EOA. The most reliable technique is using in vivo echocardiographic measurements to create tables of predicted EOAs for different valve sizes. PPM can be prevented surgically in patients at risk through aortic root enlargement (ARE). Established techniques include the posterior enlargement through Nicks and Manouguian procedures, and aortico-ventriculoplasty with the Konno-Rastan procedure, which allows for a greater enlargement but carries increased surgical risk. A contemporary development is the Yang procedure, which uses a Y-shaped incision created through the non- and left-coronary cusp commissure, undermining the nadirs of the non- and left-coronary cusps. Early results are promising and demonstrate an ability to safely increase the aortic root by up to two to three sizes. Aortic root enlargement thus remains a valuable and safe tool in addressing PPM, and should be considered during surgical planning.

Porcine bioprostheses for surgical aortic valve replacement: very long-term performance of a third-generation device

AIMS

We aimed at investigating the long-term durability of the Epic bioprosthesis for surgical aortic valve replacement (SAVR) in a single-centre series of 888 implantations (2001-2018), expanding previous evaluations with shorter follow-up.

METHODS

We retrieved prospectively collected in-hospital data and performed a systematic follow-up focusing on valve-related events (SVD, structural valve deterioration; PPM, patient-prosthesis mismatch; reoperation) (competing risks, CIF and Kaplan--Meier methods). We distinguished between SVD (permanent changes in valve function due to evolutive structural deterioration, ≥10 mmHg average gradient vs. reference echocardiography) and PPM.

RESULTS

Average age at SAVR was 75.4 ± 7 years; 855 (96.3%) bioprostheses entered the follow-up and 396 (46.4%) were alive at last assessment. Follow-up was 99.9% complete, median duration was 7.7 years (entire cohort) and 9.9 years (survivors). At 10 years, overall survival was 50% ± 1.9, freedom from SVD was 99.4% ± 0.3 (competing risks) (seven SVD events after 8.1 ± 4.3 years). Freedom from SVD at 15 years was 98.4% ± 0.8 (competing risks). Prevalence of severe PPM was higher in 19 mm (6.5%) and 21 mm (10.2%) size cohorts. PPM (severe or moderate/severe) had no significant impact on overall survival (log-rank P = 0.27 and P = 0.21, respectively). Freedom from any reintervention (reoperation or TAVI Valve-in-Valve) for SVD at 10 years was 99.4% ± 0.3 (competing risks); freedom from any valve-related reintervention was 97.4% ± 0.6 (competing risks).

CONCLUSION

The Epic bioprosthesis for SAVR is limited by nonnegligible rates of PPM, which have nonetheless no impact on late survival. This device shows excellent durability and low rates of adverse valve-related events.

Aortic valve replacement in small aortic root- Bi-leaflet mechanical valve is superior to a Mono-leaflet mechanical valve

Background

Patient prosthetic mismatch is a serious but avoidable complication of surgical aortic valve replacement (SAVR) complicated by a small aortic annulus. This study aims to compare early and midterm outcomes following aortic valve replacement (AVR) with a mono-leaflet (ML) valve and a bi-leaflet (BL) valve in a small aortic root.

Methods and selection

From January 1st, 2017 to December 31st, 2019, 98 patients diagnosed with small aortic root underwent isolated aortic valve replacement with either TTK Chitra valve (Mono-leaflet/ ML group) or St. Jude medical valve (Bi-leaflet/ BL group) of size 17/ 19 mm. Echocardiography was analyzed from medical records and telephonic follow-up.

Results

Baseline parameters were comparable. The ML group had 42 patients and the BL group had 56 patients. Aortic cross-clamp time, the incidence of severe patient prosthetic mismatch (p = 0.002) and mean, peak pressure gradients were high in the ML group. Duration of ventilation, intensive care unit (ICU) stay, the incidence of stroke, need for intra-aortic balloon pump, permanent pacemaker, dialysis, and left ventricular mass index in echocardiography were comparable between the two groups postoperatively. There was no early mortality in both group. Survival at the end of 5 years was 57 ± 14.4% in the ML group; 91.8 ± 4% in the BL group (p = 0.005). Univariate and multivariate analysis revealed elderly age as a risk factor for mortality.

Conclusion

We conclude that aortic valve replacement without any root widening procedure, using a small-sized mechanical valve provides acceptable early outcomes. Bi-leaflet mechanical valves provide better hemodynamics and survival percentage.

Acquired Von Willebrand Factor Deficiency at Patient-Prosthesis Mismatch after AVR Procedure-A Narrative Review

Acquired von Willebrand factor deficiency has been described in patients with aortic valve stenosis due to high shear forces developed during passage through the narrowed valve orifice, which determines structural changes in this molecule. Similar flow conditions are present in patients with an aortic prosthesis that presents a patient-prosthesis mismatch. Patient-prosthesis mismatch is described by the smaller effective orifice area of the prosthesis than the native valve, which would probably determine similar changes in the molecules of the von Willebrand factor, leading to acquiring von Willebrand deficiency.

Figure of eight suture technique in aortic valve replacement decreases prosthesis-patient mismatch

BACKGROUND

While the pledget suture technique has been the standard for surgical aortic. valve replacement (AVR), discussion continues regarding the possibility of the nonpledget suture technique to produce superior structural and hemodynamic parameters. This study aims to assess the effectiveness of the figure-of-eight suture technique in AVR, as determined by the incidence of prosthesis-patient mismatch (PPM).

METHODS

We reviewed records of patients (N = 629) who underwent a surgical AVR procedure between January 2011 and July 2018 at a single institution. Indexed effective orifice area values and PPM incidence were calculated from implanted valve size and patient body surface area. Incidence of none, moderate, and severe PPM was compared across AVR suture techniques.

RESULTS

A total of 570 pledget and 59 figure-of-eight patients were compared for incidence of PPM. Patients who received AVR with the pledget suture technique had significantly lower echocardiographic measurements of baseline ejection fraction than patients who had received AVR with the figure-of-eight suture technique (p = 0.003). Patients who received the figure-of eight suture had a 14% decrease in moderate PPM compared to patients who received the pledget suture (p = 0.022). Patients who received the figure-of-eight suture also had a significantly higher rate of no PPM (p = 0.044).

CONCLUSIONS

The use of the figure-of-eight suture technique in AVR can reduce the incidence of moderate PPM. While the pledget suture is the standard technique in AVR, the figure-of-eight suture technique may offer better structural and hemodynamic outcomes, especially for patients with a smaller aortic annulus.

Effect of Prosthesis-Patient Mismatch on Long-Term Clinical Outcomes After Bioprosthetic Aortic Valve Replacement

BACKGROUND

Prosthesis-patient mismatch (PPM) is common following surgical aortic valve replacement (SAVR).

OBJECTIVES

The purpose of this study was to quantify the impact of PPM on all-cause mortality, heart failure hospitalization, and reintervention following bioprosthetic SAVR.

METHODS

This observational nationwide cohort study from SWEDEHEART (Swedish Web system for Enhancement and Development of Evidence based care in Heart disease Evaluated According to Recommended Therapies) and other national registers included all patients who underwent primary bioprosthetic SAVR in Sweden from 2003 to 2018. PPM was defined according to the Valve Academic Research Consortium 3 criteria. Outcomes were all-cause mortality, heart failure hospitalization, and aortic valve reintervention. Regression standardization was used to account for intergroup differences and to estimate cumulative incidence differences.

RESULTS

We included 16,423 patients (no PPM: 7,377 [45%]; moderate PPM: 8,502 [52%]; and severe PPM: 544 [3%]). After regression standardization, the cumulative incidence of all-cause mortality at 10 years was 43% (95% CI: 24%-44%) in the no PPM group compared with 45% (95% CI: 43%-46%) and 48% (95% CI: 44%-51%) in the moderate and severe PPM groups, respectively. The survival difference at 10 years was 4.6% (95% CI: 0.7%-8.5%) and 1.7% (95% CI: 0.1%-3.3%) in no vs severe PPM and no vs moderate PPM, respectively. The difference in heart failure hospitalization at 10 years was 6.0% (95% CI: 2.2%-9.7%) in severe vs no PPM. There was no difference in aortic valve reintervention in patients with or without PPM.

CONCLUSIONS

Increasing grades of PPM were associated with long-term mortality, and severe PPM was associated with increased heart failure. Moderate PPM was common, but the clinical significance may be negligible because the absolute risk differences in clinical outcomes were small.

Outcomes Post-Nick's Aortic Root Enlargement Technique: Single-Center Experience

BACKGROUND

 Different techniques for aortic root enlargement (ARE) have been reported in the literature. Each technique comes with its own advantages and disadvantages. We report our outcomes of Nick's technique for ARE.

METHODS

 A single-center retrospective data analysis of 31 patients was performed. Patients were operated between May 2015 and November 2017 at Assuit University Heart Hospital, Assuit, Egypt.

RESULTS

 The median cardiopulmonary bypass time was 125 minutes (range: 90.0-160.0 minutes), with 90 minutes of cross-clamp (range: 60.0-110.0 minutes). Altogether 59% of the patients had mixed aortic valve diseases. Median intensive care unit and total hospital stay were 2 and 5 days, respectively. Patient-prosthesis mismatch was reported in one patient only (3.25%). Two patients died within 30 days. Median pressure gradient across the aortic valve was 20 mm Hg at 3 years of follow-up.

CONCLUSION

 The benefits of Nick's technique for ARE can be demonstrated in populations with younger patients and complicated pathology. Further research is required in larger patient populations.

Surgical versus transcatheter aortic valve replacement: Impact of patient-prosthesis mismatch on outcomes

BACKGROUND

The hemodynamics of most prosthetic valves are often inferior to that of the normal native valve, and a significant proportion of patients undergoing surgical (SAVR) or transcatheter aortic valve replacement (TAVR) have high residual transaortic pressure gradients due to prosthesis-patient mismatch (PPM). As the experience with TAVR has increased and long-term outcomes are reported, a close look at the PPM literature is required in light of new evidence.

METHODS

For this review, we searched the Embase, Medline, and Cochrane databases from 2000 to 2022. Articles reporting PPM as an outcome following aortic valve replacements were identified and reviewed.

RESULTS

The impact of PPM on clinical outcomes in aortic valve replacement has not been clear as multiple studies failed to report PPM incidence. However, the PPM outcomes after SAVR vary more widely than after TAVR, ranging from 8% to 80% in SAVR and from 24% to 35% in TAVR. Incidence of severe PPM following redo SAVR ranges from 2% to 9% and following valve-in-valve TAVR is from 14% to 33%, however, while PPM is higher in valve-in-valve TAVR, patients had better survival rates.

CONCLUSIONS

The gap between valve performance and clinical outcomes in SAVR and TAVR could be reduced by carefully selecting patients for either treatment option. Understanding predictors of PPM can add to the safety, effectiveness, and increased survival benefit of both SAVR and TAVR.

Prosthesis-patient mismatch after transcatheter aortic valve implantation

Prosthesis-patient mismatch (PPM), first described in 1978, occurs when a prosthetic valve functions normally, but has an effective orifice area that is too small relative to the patient's body surface area. It results in residual left ventricular afterload and higher transvalvular pressure gradient, which has been considered to impair prognosis. PPM following surgical aortic replacement is reportedly associated with worse clinical outcomes, such as high mortality. However, the impact of PPM on clinical outcomes after transcatheter aortic valve implantation (TAVI) remains unclear. There is conflicting evidence on the impact of PPM following TAVI due to differences across studies in terms of follow-up period, methods, patient populations, and type of bioprosthetic valve. The present review summarizes the most recent evidence on PPM after TAVI.

Less invasive aortic valve replacement using the trifecta bioprosthesis

Objectives. The safety and effectiveness of the Trifecta GT bioprosthesis (introduced in 2016) in less invasive aortic valve replacement are scarcely investigated. Our aim was to evaluate the immediate and initial follow-up results of this device in the context of less invasive surgery. We discuss patient-specific strategies for the selection of the surgical approach. Methods. A retrospective review of 133 patients undergoing AVR with the Trifecta GT through three less invasive accesses (UMS, Upper ministernotomy; RMS, Reversed ministernotomy; RAMT, Right anterior minithoracotomy) was performed. In-hospital, follow-up and hemodynamic performance (PPM, Patient-prosthesis mismatch) data were collected. Results. Among patients, 79% received UMS, 11% RMS and 10% RAMT. Selection of approach was based on preoperative anatomical analysis (CT-scan) and planned concomitant procedures. There was no operative mortality, no valve-related adverse events. There were 36 concomitant procedures. No significant intergroup differences occurred in cardiopulmonary bypass, aortic clamp, mechanical ventilation time, ICU stay and average bleeding. There were two cases of moderate PPM (1.5%) and no instances of severe PPM; there were no significant (≥2/4) perivalvular leaks. Average mean gradient at discharge was 8 ± 3 mmHg. At follow-up (average: 2.5 ± 0.9 years, 100% complete, 315 patient years) there was no mortality and no valve-related adverse event. Hemodynamic performance was maintained at follow-up. Conclusions. The optimal device for less invasive AVR needs to be individualized, as well as the selection of the surgical approach. The use of the Trifecta GT bioprosthesis appears to be reproductible whatever less invasive approach is employed, with confirmed excellent hemodynamic performance.

Prosthesis-Patient Mismatch in Small Aortic Annuli: Self-Expandable vs. Balloon-Expandable Transcatheter Aortic Valve Replacement

Prosthesis−patient mismatch (PPM) is associated with worse outcomes following surgical aortic valve replacement (SAVR). PPM has been identified in a significant proportion of TAVR, particularly in patients with small aortic annuli. Our objective was to evaluate the hemodynamic performances of balloon-expandable (BE) (Sapiens 3TM) versus two different self-expandable (SE) (Evolut ProTM, Accurate NeoTM) TAVR devices in patients with small aortic annulus defined by a computed tomography aortic annulus area (AAA) between 330 and 440 mm2. We enrolled 131 consecutive patients corresponding to 76 Sapiens 3 23 mm (58.0%), 26 Evolut Pro (19.9%) and 29 Accurate Neo (22.1%). Mean age was 82.5 ± 7.06 years, 22.9% of patients were male and mean Euroscore was 4.0%. Mean AAA was 374 ± 27 mm2 for Sapiens 3, 383 ± 29 mm2 for Corevalve Evolut Pro and 389 ± 25 mm2 for Accurate Neo. BE devices were associated with significantly higher rates of PPM (39.5%) as compared to SE devices (15.4% for Corevalve Evolut Pro and 6.9% for Accurate Neo) (p < 0.0001). Paravalvular leaks ≥ 2/4 were more often observed in SE devices (15.4% for Corevalve Evolut Pro and 17.2% for Accurate Neo) than in BE devices (2.6%) (p = 0.007). In conclusion, SE TAVR devices did achieve better hemodynamic results despite higher rates of paravalvular leaks. Therefore, SE TAVI devices could be considered as first choice in small aortic anatomy.

Patient Prosthesis Mismatch After SAVR and TAVR

Patient-prosthesis mismatch (PPM) remains one out of many factors to be considered during decision-making for the treatment of aortic valve pathologies. The idea of adequate sizing of a prosthetic heart valve was established by Rahimtoola already in 1978. In this article, the author described the phenomenon that the orifice area of a prosthetic heart valve may be too small for the individual patient. PPM is assessed by measurement or projection of the prosthetic effective orifice area indexed to body surface area (iEOA), while it is recommended to use different cut point values for non-obese and obese patients for the categorization of moderate and severe PPM. Several factors influence the accuracy of both the projected and the measured iEOA for PPM assessment, which leads to a certain number of false assignments to the PPM or no PPM group. Despite divergent findings on the impact of PPM on clinical outcomes, there is consensus that PPM should be avoided to prevent sequelae of increased prosthetic gradients after aortic valve replacement. To prevent PPM, it is required to anticipate the iEOA of the prosthesis prior to the procedure. The use of adequate reference tables, derived from echocardiographically measured mean effective orifice area (EOA) values from preferably large numbers of patients, is most appropriate to predict the iEOA. Such tables should be used also for transcatheter heart valves in the future. During the decision-making process, all available options should be taken into account for the individual patient. If the predicted size and type of a surgical prosthesis cannot be implanted, additional surgical procedures, such as annular enlargement with the Manougian technique, or alternative procedures, such as transcatheter aortic valve implantation (TAVI) can prevent PPM. PPM prevention for TAVI patients is a new field of interest and includes anticipation of the iEOA, prosthesis selection, and procedural strategies.

2-Year Outcomes After Transcatheter Versus Surgical Aortic Valve Replacement in Low-Risk Patients

BACKGROUND

The Evolut Low Risk Trial (Medtronic Evolut Transcatheter Aortic Valve Replacement in Low Risk Patients) showed that transcatheter aortic valve replacement (TAVR) with a supra-annular, self-expanding valve was noninferior to surgery for the primary endpoint of all-cause mortality or disabling stroke at 2 years. This finding was based on a Bayesian analysis performed after 850 patients had reached 1 year of follow-up.

OBJECTIVES

The goal of this study was to report the full 2-year clinical and echocardiographic outcomes for patients enrolled in the Evolut Low Risk Trial.

METHODS

A total of 1,414 low-surgical risk patients with severe aortic stenosis were randomized to receive TAVR or surgical AVR. An independent clinical events committee adjudicated adverse events, and a central echocardiographic core laboratory assessed hemodynamic endpoints.

RESULTS

An attempted implant was performed in 730 TAVR and 684 surgical patients from March 2016 to May 2019. The Kaplan-Meier rates for the complete 2-year primary endpoint of death or disabling stroke were 4.3% in the TAVR group and 6.3% in the surgery group (P = 0.084). These rates were comparable to the interim Bayesian rates of 5.3% with TAVR and 6.7% with surgery (difference: -1.4%; 95% Bayesian credible interval: -4.9% to 2.1%). All-cause mortality rates were 3.5% vs 4.4% (P = 0.366), and disabling stroke rates were 1.5% vs 2.7% (P = 0.119), respectively. Between years 1 and 2, there was no convergence of the primary outcome curves.

CONCLUSIONS

The complete 2-year follow-up from the Evolut Low Risk Trial found that TAVR is noninferior to surgery for the primary endpoint of all-cause mortality or disabling stroke, with event rates that were slightly better than those predicted by using the Bayesian analysis. (Medtronic Evolut Transcatheter Aortic Valve Replacement in Low Risk Patients [Evolut Low Risk Trial]; NCT02701283).

Impact of Prosthesis-Patient Mismatch on Hemodynamics During Exercise in Patients With Aortic Stenosis After Transcatheter Aortic Valve Implantation With a Balloon-Expandable Valve

Background

There is no evidence of hemodynamic performance during exercise in patients with aortic stenosis (AS) after transcatheter aortic valve implantation (TAVI). This study aimed to investigate the changes in kinematic hemodynamics during exercise and determine the impact of prosthesis-patient mismatch (PPM) on the hemodynamics of transcatheter heart valves using exercise stress echocardiography (ESE) in AS patients after TAVI.

Methods and Results

This study enrolled 77 consecutive patients (mean age 82 ± 5 years, 50.6% male) who underwent ESE 3–6 months after TAVI with a balloon-expandable valve. The effective orifice area index at rest was significantly correlated with the mean pressure gradient (PG) during exercise (p <0.001). The patients were divided into two groups according to the presence of PPM (PPM and non-PPM groups). During exercise, the patients with PPM had a higher left ventricular ejection fraction (74.6 ± 6.1% vs. 69.7 ± 9.6%, p = 0.048), a lower stroke volume index (47.2 ± 14.0 ml/m² vs. 55.6 ± 14.5 ml/m², p = 0.037), a significantly higher mean transvalvular PG (21.9 ± 9.1 mmHg vs. 12.2 ± 4.9 mmHg, p = 0.01) and an increased mean PG from rest to exercise (5.7 ± 3.5 mmHg vs. 2.3 ± 2.8 mmHg, p <0.001) compared with patients without PPM. Patients with PPM had a higher pulmonary artery systolic pressure (SPAP) during exercise (57.3 ± 13.8 mmHg vs. 49.7 ± 10.9 mmHg, p = 0.021) and a higher incidence of exercise-induced pulmonary hypertension (43.8 vs. 15.0%, p = 0.037) than patients without PPM. PPM was strongly associated with exercise-induced pulmonary hypertension (hazard ratio: 3.570, p = 0.013).

Conclusions

AS patients with PPM after TAVI showed a disproportionate increase in the transvalvular PG and SPAP during exercise, and PPM was associated with exercise-induced pulmonary hypertension.

Patient–Prosthesis Mismatch in Contemporary Small-Size Mechanical Prostheses Does Not Impact Survival at 10 Years

Background: The effect of PPM in mechanical prostheses on long-term survival is not well-established. Methods: Patients who received a 21 mm or smaller aortic valve between 2000 and 2011 were retrospectively analyzed (n = 416). Propensity matching was used in order to account for baseline differences in patient subgroups (PPM vs. no PPM; severe PPM vs. no severe PPM). Results: Five- and ten-year survival was 78 ± 3.52% and 64.51 ± 4.51% in patients with PPM, versus 83.3 ± 3.12% and 69.37 ± 4.36% in patients without (p = 0.28) when analyzed at 10.39 ± 5.25 years after the primary procedure. Independent risk factors for impaired survival, after matching, were age, serum creatinine, and severe pulmonary hypertension. Five- and ten-year survival in patients with severe PPM was 73.34 ± 6.01% and 61.76 ± 8.17%, respectively, versus 74.72 ± 5.68% and 67.50 ± 7.09% in those without (p = 0.49), at 8.82 ± 5.17 years after SAVR. Age was the only independent variable that influenced long-term survival when severe PPM was added to the model. Conclusions: PPM or severe PPM does not impact long-term survival up to 10 years in mechanical valve recipients when matching for preoperative variables.

Racial Differences in the Incidence and Impact of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Replacement

OBJECTIVES

The aim of this study was to compare the incidence and prognostic significance of prosthesis-patient mismatch (PPM) after transcatheter aortic valve replacement (TAVR) according to racial groups.

BACKGROUND

PPM after TAVR may be of more concern in Asian populations considering their relatively small annular and valve sizes compared with Western populations.

METHODS

TP-TAVR (Transpacific TAVR Registry) was an international multicenter cohort study of patients with severe aortic stenosis who underwent TAVR in the United States and South Korea from January 2015 to November 2019. PPM was defined as moderate (0.65-0.85 cm²/m²) or severe (<0.65 cm²/m²) at the indexed effective orifice area. The primary outcome was a composite of death, stroke, or rehospitalization at 1 year.

RESULTS

Among 1,101 eligible patients (533 Asian and 569 non-Asian), the incidence of PPM was significantly lower in the Asian population (33.6%; moderate, 26.5%; severe, 7.1%) than in the non-Asian population (54.5%; moderate, 29.8%; severe, 24.7%). The 1-year rate of the primary outcome was similar between the PPM and non-PPM groups (27.5% vs 28.1%; P = 0.69); this pattern was consistent between Asian (25.4% vs 25.2%; P = 0.31) and non-Asian (28.7% vs 32.1%; P = 0.97) patients. After multivariable adjustment, the risk for the primary outcome did not significantly differ between the PPM and non-PPM groups in the overall population (HR: 0.95; 95% CI: 0.74-1.21), in Asian patients (HR: 1.07; 95% CI: 0.74-1.55), and in non-Asian patients (HR: 0.86; 95% CI: 0.63-1.19).

CONCLUSIONS

In this study of patients with severe aortic stenosis who underwent TAVR, the incidence of PPM was significantly lower in Asian patients than in non-Asian patients. The 1-year risk for the primary composite outcome was similar between the PPM and non-PPM groups regardless of racial group. (Transpacific TAVR Registry [TP-TAVR]; NCT03826264).

Updates on the Latest Surgical Approach of the Aortic Stenosis

Over the last twenty years, we marked significant progresses in the field of tissue engineering and the development of new aortic valve structural and delivery systems. These continuous iterations on the field, have completely changed the surgical indications and approaches for AVR. Nowadays, therapeutic decisions are endorsed by international guidelines; however, new technical advances need a new integrated approach. The clinical scenarios issued from the interaction between the Guidelines and the newest approaches and technologies are regularly on debate by the Heart Team. We will present some of our most encountered situations and the pattern of our therapeutic decisions. To easily navigate through Guidelines and clinical scenarios, we reported in this review a simplified and easy to use Clinical decision-making algorithm that may be a valuable tool in our daily practice.

Mid-term clinical and health-related quality of life outcomes for the Trifecta bioprosthesis

Background

The Trifecta valve has been reported to have excellent hemodynamics. Controversy exists on occurrence of patient-prosthesis mismatch (PPM) and data on mid-term outcome is sparse. Health-related quality of life (HRQoL) assessment for the Trifecta valve has not been reported before. The aim of this study was to report the mid-term clinical and HRQoL outcomes in patients undergoing Trifecta valve implantation at our institution.

Methods

In this prospective, observational study, patients undergoing an aortic valve replacement (AVR) using the Trifecta valve were included. Data collection was retrospective from prospectively collected institutional database. Clinical and echocardiographic data were collected prospectively during follow-up. Quality of life was assessed using the Short Form-36 (SF-36) questionnaire.

Results

Forty-seven patients were included in the study of which 9 (19%) were women. Isolated AVR was carried out in 33 (70%) patients. In-hospital mortality and 30-day mortality were 1 (2.1%) and 2 (4.2%), respectively. With a mean indexed effective orifice area (iEOA) 0.96 ± 0.1, none of the patients had severe PPM. Moderate PPM was seen in 19%. The mean follow-up was 3 ± 1.7 years. The 5-year survival estimate was 83.2% in the overall cohort, 81.4% in the isolated and 87.5% in the concomitant procedure group. Freedom from re-operation and structural valve degeneration at 5 years was 95.7% and 97.8%. The mean physical health composite was 69.24 ± 2 and the mean mental health composite was 69.7 ± 25, indicating excellent mental and physical well-being among patients.

Conclusion

The Trifecta valve provides satisfactory hemodynamics, survival and freedom from re-operation and excellent HRQoL at mid-term follow-up.

Long-term outcomes after aortic valve replacement using a 19-mm bioprosthesis

OBJECTIVES

Transcatheter aortic valve replacement is known to be associated with improved haemodynamics in patients with aortic stenosis and a small aortic annulus. However, limited benchmark data are available regarding the long-term outcomes in patients treated with surgical aortic valve replacement (SAVR). We investigated the long-term outcomes of SAVR using a 19-mm bioprosthesis.

METHODS

This study included consecutive patients who underwent SAVR using a 19-mm bioprosthesis at our hospital between 2008 and 2012.

RESULTS

In a total of 132 patients, moderate and severe prosthesis-patient mismatch occurred in 36 (27.3%) and 7 patients (5.3%), respectively. The median follow-up period was 7.7 years. The overall 5- and 10-year survival rates were 79.4% and 52.9%, respectively. The 5- and 10-year freedom from major adverse valve-related events rates were 89.6% and 74.2%, respectively. Neither moderate nor severe prosthesis-patient mismatch was associated with late mortality, major adverse valve-related events or heart failure. Follow-up echocardiographic data were obtained at a median interval of 4.8 years in 80% of patients who survived ≥6 months postoperatively. Follow-up echocardiographic data showed a significantly increased left ventricular ejection fraction, decreased mean transvalvular/transprosthetic pressure gradients and a decreased mean left ventricular mass. At follow-up, we observed moderate or severe haemodynamic structural valve deterioration in 17 patients; however, structural valve deterioration did not affect late survival or freedom from major adverse valve-related events rates, or heart failure.

CONCLUSIONS

SAVR using the 19-mm bioprosthesis was associated with satisfactory long-term clinical and haemodynamic outcomes.

Prosthesis-patient mismatch affects late survival after valve surgery for severe aortic stenosis

BACKGROUND

The effect of prosthesis-patient mismatch (PPM) on late survival after aortic valve replacement (AVR) in patient with symptomatic severe aortic stenosis (AS) remains unclear. Also, late follow-up in previous studies is confined to only one decade. We aimed to determine the effect of PPM on late survival after isolated AVR for symptomatic severe AS during 25 years of follow-up.

METHODS

In this retrospective cohort study, Kaplan-Meier survival analysis was performed to determine late survival in 404 consecutive patients with moderate PPM (N.=86), severe (N.=11), or no/mild PPM (N.=307) after isolated AVR for symptomatic severe AS during a mean follow-up of 25.0±2.9 years. Moderate, severe, and no/mild PPM were defined as indexed effective orifice area of >0.65≤0.85, ≤0.65, and >0.85 cm2/m2, respectively. Multivariable analysis was performed to identify possible independent predictors of decreased late survival, including moderate or severe PPM.

RESULTS

Late survival of patients with severe PPM was worse in comparison with those with no/mild PPM: 7.4±2.6 (95% confidence interval 2.2-12.5) vs. 13.6±0.5 (95% confidence interval 12.6-14.6) years, respectively; P=0.020. Late survival of patients with moderate PPM was similar to those with no/mild PPM. Severe PPM was an independent predictor of decreased late survival: hazards ratio 4.002 (95% confidence interval 1.869-8.569); P<0.001. Moderate PPM was not an independent predictor of decreased late survival.

CONCLUSIONS

Severe PPM was independently associated with decreased late survival after isolated AVR for symptomatic severe AS during a mean follow-up of 25.0±2.9 years. Therefore, severe PPM should be prevented as much as possible.

Aortic valve neocuspidization with autologous pericardium in adult patients: UK experience and meta-analytic comparison with other aortic valve substitutes

OBJECTIVES

We sought to provide further evidence on the safety and efficacy of aortic valve neocuspidization (AVNeo) using autologous pericardium in adult patients with aortic valve disease by reporting clinical and echocardiographic results from the first UK experience and performing a meta-analytic comparison with other biological valve substitutes.

METHODS

We reported clinical and echocardiographic outcomes of 55 patients (mean age 58 ± 15 years) undergoing AVNeo with autologous pericardium in 2 UK centres from 2018 to 2020. These results were included in a meta-analytic comparison between series on AVNeo (7 studies, 1205 patients, mean weighted follow-up 3.6 years) versus Trifecta (10 studies, 8705 patients, 3.8 years), Magna Ease (3 studies, 3137 patients, 4.1 years), Freedom Solo (4 studies, 1869 patients, 4.4 years), Freestyle (4 studies, 4307 patients, 7 years), Mitroflow (4 studies, 4760 patients, 4.1 years) and autograft aortic valve (7 papers, 3839 patients, 9.1 years).

RESULTS

In the present series no patients required intraoperative conversion. After mean follow-up of 12.5 ± 0.9 months, 3 patients presented with endocarditis and 1 required reintervention. The remaining patients had absent or mild aortic valve insufficiency with very low peak and mean transvalvular gradients (16 ± 3.7 and 9 ± 2.2 mmHg, respectively). Meta-analytic estimates showed non-significant difference between AVNeo and all but Magna Ease valves with regards to structural valve degeneration, reintervention and endocarditis. When compared Magna Ease valve, AVNeo and other valve substitutes showed an excess of valve-related events.

CONCLUSIONS

AVNeo is safe, associated with excellent haemodynamic profile. Its midterm risk of valve-related events is comparable to most biological valve substitutes. Magna Ease is potentially the best biological choice as far as risk of reintervention is concerned.

The relation of structural valve deterioration to adverse remodelling and outcome in patients with biological heart valve prostheses

AIMS

Native valve aortic stenosis is associated with adverse remodelling of the left ventricle and remodelling is stopped or even reversed with aortic valve replacement (AVR). However, the degeneration of bioprostheses and development of structural valve deterioration (SVD) may affect this.

METHODS AND RESULTS

To assess the association with SVD, remodelling and outcome 451 patients from a single surgical centre who had undergone AVR with a Mitroflow pericardial bioprosthesis were studied. All patients were assessed in 2014 and a subgroup of patients (N = 327) were re-exanimated again after at least 18 months [median time of 27 (interquartile range, IQR 26-33) months] including echocardiography, measurements of N-terminal pro-brain natriuretic peptide, and assessment of functional status. SVD was based on echocardiography. Moderate SVD was present in 63 patients (14%) and severe SVD in 19 (4%), in the subgroup with follow-up echocardiography 48 patients (15%) patients had moderate to severe SVD at first examination. Patients with SVD had significantly greater increase in left ventricular (LV) mass index [21.6 g/m2 (IQR 5.7-48.3 g/m2) vs. 9.1 g/m2 (-8.6 to 27.3 g/m2), P = 0.01]. Further, patients with SVD had lower LV ejection fraction [55% (IQR 51-62%) vs. 60% (IQR 54-63%), P = 0.01] at follow-up. During follow-up, 94 patients (21%) met the composite endpoint of death or reoperation due to SVD and 41 patient readmitted for heart failure. In multivariable Cox regression analysis, severe SVD [hazard ratio (HR) 2.64 (1.37-5.07), P = 0.004] was associated with composite endpoint, and readmission for heart failure [HR 3.82 (1.53-9.51), P = 0.004].

CONCLUSION

SVD in aortic bioprostheses is associated with adverse LV remodelling and adverse outcome.

Clinical and Technical Challenges of Prosthesis-Patient Mismatch After Transcatheter Aortic Valve Implantation

Prosthesis-patient mismatch (PPM) is present when the effective area of a prosthetic valve inserted into a patient is inferior to that of a normal human valve; the hemodynamic consequence of a valve too small compared with the size of the patient's body is the generation of higher than expected transprosthetic gradients. Despite evidence of increased risk of short- and long-term mortality and of structural valve degeneration in patients with PPM after surgical aortic valve replacement, its clinical impact in patients subject to transcatheter aortic valve implantation (TAVI) is yet unclear. We aim to review and update on the definition and incidence of PPM after TAVI, and its prognostic implications in the overall population and in higher-risk subgroups, such as small aortic annuli or valve-in-valve procedures. Last, we will focus on the armamentarium available in order to reduce risk of PPM when planning a TAVI procedure.

Early outcomes of patient-prosthesis mismatch following aortic valve replacement

INTRODUCTION

Patient-prosthesis mismatch (PPM) has been associated with numerous short- and long-term adverse events. This study aimed to evaluate the effect of PPM on early postoperative results after aortic valve replacement (AVR) in daily practice.

METHODS

In this single-centre retrospective study, 150 non-consecutive patients from March 2019 to January 2020 with clinically indicated AVR with/without concomitant surgery were analysed. The study protocol included operative mortality, complication rate, and pre- and postoperative echocardiographic data. PPM was considered severe with indexed effective orifice area at <0.65 cm²/m², moderate at 0.65-0.85 cm²/m² and none at >0.85 cm²/m².

RESULTS

Moderate PPM was observed in 16 patients (10.6%). No patient had severe PPM. PPM was not related to early mortality (r = 0.40, p = 0.630), intra- (r = -0.076, p = 0.352) and postoperative (r = -0.0134, p = 0.102) events.

CONCLUSION

In this study, moderate PPM was a frequent finding after AVR, whereas severe PPM was not observed. PPM did not affect the early results after AVR. A long-term follow-up study in a large patient population is required to assess the actual influence of residual PPM.

Bioprosthetic aortic valve diameter and thickness are directly related to leaflet fluttering: Results from a combined experimental and computational modeling study

OBJECTIVE

Bioprosthetic heart valves (BHVs) are commonly used in surgical and percutaneous valve replacement. The durability of percutaneous valve replacement is unknown, but surgical valves have been shown to require reintervention after 10 to 15 years. Further, smaller-diameter surgical BHVs generally experience higher rates of prosthesis-patient mismatch, which leads to higher rates of failure. Bioprosthetic aortic valves can flutter in systole, and fluttering is associated with fatigue and failure in flexible structures. The determinants of flutter in BHVs have not been well characterized, despite their potential to influence durability.

METHODS

We use an experimental pulse duplicator and a computational fluid-structure interaction model of this system to study the role of device geometry on BHV dynamics. The experimental system mimics physiological conditions, and the computational model enables precise control of leaflet biomechanics and flow conditions to isolate the effects of variations in BHV geometry on leaflet dynamics.

RESULTS

Both experimental and computational models demonstrate that smaller-diameter BHVs yield markedly higher leaflet fluttering frequencies across a range of conditions. The computational model also predicts that fluttering frequency is directly related to leaflet thickness. A scaling model is introduced that rationalizes these findings.

CONCLUSIONS

We systematically characterize the influence of BHV diameter and leaflet thickness on fluttering dynamics. Although this study does not determine how flutter influences device durability, increased flutter in smaller-diameter BHVs may explain how prosthesis-patient mismatch could induce BHV leaflet fatigue and failure. Ultimately, understanding the effects of device geometry on leaflet kinematics may lead to more durable valve replacements.

Moderate Aortic Stenosis in Patients With Heart Failure and Reduced Ejection Fraction

BACKGROUND

The study investigators previously reported that moderate aortic stenosis (AS) is associated with a poor prognosis in patients with heart failure (HF) with reduced left ventricular ejection fraction (LVEF) (HFrEF). However, the respective contribution of moderate AS versus HFrEF to the outcomes of these patients is unknown.

OBJECTIVES

This study sought to determine the impact of moderate AS on outcomes in patients with HFrEF.

METHODS

The study included 262 patients with moderate AS (aortic valve area >1.0 and <1.5 cm²; and peak aortic jet velocity >2 and <4 m/s, at rest or after dobutamine stress echocardiography) and HFrEF (LVEF <50%). These patients were matched 1:1 for sex, age, estimated glomerular filtration rate, New York Heart Association functional class III to IV, presence of diabetes, LVEF, and body mass index with patients with HFrEF but no AS (i.e., peak aortic jet velocity <2 m/s). The endpoints were all-cause mortality and the composite of death and HF hospitalization.

RESULTS

A total of 262 patients with HFrEF and moderate AS were matched with 262 patients with HFrEF and no AS. Mean follow-up was 2.9 ± 2.2 years. In the moderate AS group, mean aortic valve area was 1.2 ± 0.2 cm², and mean gradient was 14.5 ± 4.7 mm Hg. Moderate AS was associated with an increased risk of mortality (hazard ratio [HR]: 2.98; 95% confidence interval [CI]: 2.08 to 4.31; p < 0.0001) and of the composite of HF hospitalization and mortality (HR: 2.34; 95% CI: 1. 72 to 3.21; p < 0.0001). In the moderate AS group, aortic valve replacement (AVR) performed in 44 patients at a median follow-up time of 10.9 ± 16 months during follow-up was associated with improved survival (HR: 0.59; 95% CI: 0.35 to 0.98; p = 0.04). Notably, surgical AVR was not significantly associated with improved survival (p = 0.92), whereas transcatheter AVR was (HR: 0.43; 95% CI: 0.18 to 1.00; p = 0.05).

CONCLUSIONS

In this series of patients with HFrEF, moderate AS was associated with a marked incremental risk of mortality. AVR, and especially transcatheter AVR during follow-up, was associated with improved survival in patients with HFrEF and moderate AS. These findings provide support to the realization of a randomized trial to assess the effect of early transcatheter AVR in patients with HFrEF and moderate AS.

Predictors and Clinical Impact of Prosthesis-Patient Mismatch After Self-Expandable TAVR in Small Annuli

OBJECTIVES

The aim of this study was to define predictors of prosthesis-patient mismatch (PPM) and its impact on mortality after transcatheter aortic valve replacement (TAVR) with self-expandable valves (SEVs) in patients with small annuli.

BACKGROUND

TAVR seems to reduce the risk for PPM compared with surgical aortic valve replacement, especially in patients with small aortic annuli. Nevertheless, predictors and impact of PPM in this population have not been clarified yet.

METHODS

Predictors of PPM and all-cause mortality were investigated using multivariable logistic regression analysis from the cohort of the TAVI-SMALL (International Multicenter Registry to Evaluate the Performance of Self-Expandable Valves in Small Aortic Annuli) registry, which included patients with severe aortic stenosis and small annuli (annular perimeter <72 mm or area <400 mm² on computed tomography) treated with transcatheter SEVs: 445 patients with (n = 129) and without (n = 316) PPM were enrolled.

RESULTS

Intra-annular valves conferred increased risk for PPM (odds ratio [OR]: 2.36; 95% confidence interval [CI]: 1.16 to 4.81), while post-dilation (OR: 0.46; 95% CI: 0.25-0.84) and valve oversizing (OR: 0.53; 95% CI: 0.28-1.00) seemed to protect against PPM occurrence. At a median follow-up of 354 days, patients with severe PPM, but not those with moderate PPM, had a higher all-cause mortality rate compared with those without PPM (log-rank p = 0.008). Multivariable Cox regression confirmed severe PPM as an independent predictor of all-cause mortality (hazard ratio: 4.27; 95% CI: 1.34 to 13.6).

CONCLUSIONS

Among patients with aortic stenosis and small aortic annuli undergoing transcatheter SEV implantation, use of intra-annular valves yielded higher risk for PPM; conversely, post-dilation and valve oversizing protected against PPM occurrence. Severe PPM was independently associated with all-cause mortality.

Hemodynamically significant prosthesis-patient mismatch can be predicted and is associated with early prosthetic valve dysfunction in aortic bioprosthesis

OBJECTIVES

To evaluate the accuracy of predicted prosthesis-patient mismatch (PPM) regarding actual PPM measured postoperatively. To assess the association between PPM and prosthetic valve dysfunction.

METHODS

Retrospective cohort study including adult patients after aortic valve replacement surgery with a biological prosthesis. Predicted PPM status was determined using mean reference effective orifice area indexed to total body surface (iEOA), without considering reference standard deviations. Postoperative PPM status was determined by measuring iEOA within the first 60 postoperative days. Prosthetic valve dysfunction was defined as thrombosis, pannus, valve degeneration, and/or disruption.

RESULTS

205 patients were enrolled between January 2003 and June 2017: predicted PPM was absent in 52 patients (25.4%), moderate in 137 patients (66.8%), and severe in 16 patients (7.8%). After surgery, the actual postoperative iEOA was measured: 53 (25.9%) did not have PPM, 73 had moderate PPM (35.6%), and 79 had severe PPM (38.5%). Predicted PPM identified the presence of hemodynamically significant actual postoperative PPM (OR = 2.56; 95%CI 1.30-5.05; P = .006), though not its degree of severity. Prosthetic valve dysfunction was more frequent among patients with hemodynamically significant PPM (53.9% vs. 11.3%; P < .001), compared to those without PPM. The association between PPM and prosthetic valve dysfunction was maintained after adjusting for gender, age, and ever-smoking (OR = 9.03; P < .001). The incidence of thrombosis or pannus was also nonsignificantly higher in patients with moderate or severe PPM.

CONCLUSIONS

Predicted PPM identifies the presence, possibly not the severity, of actual postoperative PPM. Moderate or severe PPM is associated with prosthetic valve dysfunction. Actual postoperative prosthesis-patient mismatch measured within 60 postoperative days showed a distinctive hemodynamic profile and presented a stronger association with prosthetic valve dysfunction than predicted prosthesis-patient mismatch. A. Echocardiographic follow-up in patients according to the actual postoperative PPM measured within 60 postoperative days. B. Prediction of prosthetic valve dysfunction based on preoperative predicted PPM or on actual postoperative PPM within 60 postoperative days. PPM: prosthesis-patient mismatch. OR: Odds ratio.

Blood flow energy loss: a predictor for the recovery of left ventricular function after bioprosthetic aortic valve replacement

OBJECTIVES

It is difficult to estimate the improvement in left ventricular (LV) function after aortic valve replacement (AVR). The present study aimed to evaluate whether energy loss (EL) can predict the postoperative LV function after AVR.

METHODS

Nine patients who underwent AVR with a bioprosthetic valve were enrolled in the present study. Porcine prostheses were used in 5 patients and bovine pericardial prostheses were used in 4 patients. The aortic flow pattern was visualized and EL and cardiac output (CO) were measured using 4-dimensional flow magnetic resonance imaging from the LV to the descending aorta; the EL/CO ratio in the extracted area was calculated as total EL/CO ratio.

RESULTS

With a porcine valve, a severe helical flow was observed in the ascending aorta during the holosystolic phase. In contrast, with a bovine pericardial valve, straight transvalvular aortic flow was observed in the early systolic phase and 2 large vortical flows occurred on both sides of the greater and lesser curvature of the ascending aorta after the mid-systolic period. The total EL/CO ratio was strongly correlated with LV ejection fraction improvement after AVR (r = 0.74, P = 0.02).

CONCLUSIONS

The aortic flow pattern is different between the porcine valve and bovine pericardial valve. The total EL/CO ratio is a valuable tool for evaluating the postoperative LV ejection fraction improvement after AVR. Optimization of total EL/CO ratio would have potential to improve haemodynamic performances after AVR.

The impact of patient-prosthesis mismatch on early and long-term survival after aortic replacement with the Edwards Perimount valve: A propensity score-matched analysis

BACKGROUND

To investigate the impact of severe patient-prosthesis mismatch (PPM) related to the Edwards Lifesciences Perimount (EP) bioprosthesis in the aortic position on early in-hospital outcomes and long-term survival.

METHODS

A total of 5964 consecutive patients underwent aortic valve replacement at the Bristol Heart Institute between 1998 and 2014, 2667 representing the cohort of this study received EP. PPM was defined severe as EOAi < 0.65 cm² /m² . To minimize bias, propensity score matching was conducted and two groups A and B (without and with severe PPM) of 320 patients with similar preoperative characteristics were matched. We assessed early in-hospital outcomes including CVA, re-exploration for bleeding, low cardiac output, wound infection, acute renal injury, length of hospital stay, and long-term survival for both groups in unmatched and matched populations.

RESULTS

In the unmatched analysis, 18.3% of patients had severe PPM. Severe PPM was not associated with increased in-hospital mortality (4.5% vs. 2.9%, respectively, p = .09) or any other early adverse outcomes except increased length of hospital stay (10.57 ± 8.2 vs. 11.7 ± 9.4, respectively, p = .01). Long-term survival differed significantly between groups at 2 and 8 years (91.8% vs. 91.4% and 60.5% vs. 55.7%, respectively, p = .02). Matched analysis showed no differences between the groups in early health outcomes and overall survival at 2 and 8 years was also similar (89.7% vs. 91% and 57.3% vs. 58%, group A vs. B, respectively p = .9).

CONCLUSION

Presence of PPM does not seem to affect early in-hospital outcomes or late survival when using EP in patients undergoing aortic valve replacement.

A Retrospective Comparison of Hemodynamic and Clinical Outcomes between Two Differently Designed Aortic Bioprostheses for Small Aortic Annuli

The Trifecta valve has externally mounted leaflets; it differs from classic internally mounted valves (e.g., Carpentier-Edwards [C-E]). We evaluated post-implantation hemodynamics and clinical outcomes of these bioprostheses in small aortic annuli. From January 2015 to April 2019, 490 patients who underwent aortic valve replacement (AVR) were reviewed retrospectively. Altogether, 183 patients received 19 or 21 mm diameter C-E (n = 121) or Trifecta (n = 62) prostheses. To minimize confounding variables, we performed propensity-score matching analysis. The mean transvalvular pressure gradient (TVPG) was significantly lower in the Trifecta than in the C-E group at discharge (12.9 ± 4.8 vs. 15.0 ± 5.3 mmHg, p = 0.044). TVPG change over time was not significantly different between groups (p = 0.357). Left ventricular mass index decreased postoperatively (reduction: C-E, 28.1%; Trifecta, 30.1%, p = 0.879). No late mortality, severe patient–prosthesis mismatch, moderate-to-severe paravalvular leakage, structural valve degeneration, or valve thromboses were observed. Freedom from valve-related events at 3 years were similar for C-E (97.9% ± 2.1%) and Trifecta (97.7% ± 2.2%) patients (log-rank p = 0.993). Bioprosthesis design for small annuli significantly affected TVPG immediately after AVR. However, hemodynamics over time and clinical outcomes did not differ between the two designs.

Prosthesis-patient mismatch after surgical aortic valve replacement in patients with aortic stenosis

OBJECTIVES

The issue of prosthesis-patient mismatch (PPM) after surgical aortic valve replacement (SAVR) has been a controversial topic. We sought to evaluate the long-term clinical impacts of PPM in patients undergoing SAVR in an updated, homogeneous cohort.

METHODS

Using the prospective institutional database, we identified 895 adult patients (median age 66, interquartile range 58-72; 45.6% women) who underwent isolated SAVR from January 2000 to March 2016. Those with pure aortic insufficiency and concomitant other cardiac operations were excluded from this study cohort. The presence of a significant PPM was defined as an indexed effective orifice area 0.85 cm2/m2 or less. The outcome of interest was all-cause deaths. Propensity score matching was performed for adjusting bias.

RESULTS

Significant PPM was present in 247 patients (27.6%). During the follow-up period (mean 71.2 ± 51.04 months), 134 patients (15%) died. Survival rates at 10 and 15 years were 78.3% vs 83.8% and 71.3% vs 57.6% in the PPM and non-PPM groups (P = 0.972). Risk factor analysis indicated that developing PPM was not associated with a risk of death. After propensity score matching (1:1), developing PPM was not a risk factor for long-term death as well (P = 0.584).

CONCLUSIONS

Significant PPM was common after SAVR in patients with aortic stenosis. However, there was no significant difference in survival rate between those with and without PPM.

Aortic root widening: “pro et contra”

In patients with a small aortic annulus, the clinical benefits of aortic valve replacement depend on avoidance of patient-prosthesis mismatch as it is associated with reduced overall survival. Aortic root widening or enlargement is a useful technique to implant larger valve prosthesis to prevent patient-prosthesis mismatch. Posterior annular enlargement is the commonest technique used for aortic root enlargement. Consistent enlargement of the aortic root requires more extensive procedures like Manouguian or Konno-Rastan techniques. The patients commonly selected are younger patients with good life expectancy. However, caution is advised in applying this procedure in elderly patients, patients with heavily calcified annulus and when performing concomitant procedures. There is no definitive conclusion on the best material to use for the reconstruction of aortic annulus and aorta in aortic root enlargement procedures.

Impact of the Trifecta bioprosthetic valve in patients with low-flow severe aortic stenosis

Aortic stenosis (AS) is the most common valve disorder in advanced age. Previous reports have shown that low-flow status of the left ventricle is an independent predictor of cardiovascular mortality after surgery. The Trifecta bioprosthesis has recently shown favorable hemodynamic performance. This study aimed to evaluate the effect of the Trifecta bioprosthesis, which has a large effective orifice area, in patients with low-flow severe AS who have a poor prognosis. We retrospectively evaluated 94 consecutive patients with severe AS who underwent aortic valve replacement (AVR). Patients were divided into two groups according to the stroke volume index (SVI): low-flow (LF) group (SVI < 35 ml/m², n = 22) and normal-flow (NF) group (SVI ≥ 35 ml/m², n = 72). Patients’ characteristics and early and mid-term results were compared between the two groups. There were no differences in patients’ characteristics, except for systolic blood pressure (LF:NF = 120:138 mmHg, p < 0.01) and the rate of atrial fibrillation between the groups. A preoperative echocardiogram showed that the pressure gradient was higher in the NF group than in the LF group, but aortic valve area was similar. The Trifecta bioprosthesis size was similar in both groups. The operative outcomes were not different between the groups. Severe patient–prosthesis mismatch (PPM) (< 0.65 cm²/m²) was not observed in either of the groups. There were no significant differences in mid-term results between the two groups. The favorable hemodynamic performance of the Trifecta bioprosthesis appears to have the similar outcomes in the LF and NF groups. AVR with the Trifecta bioprosthesis should be considered for avoidance of PPM, particularly in AS patients with LV dysfunction.

Elevated Prosthetic Valve Gradients: What to Consider When Determining an Etiology

DOPPLER echocardiography is a useful noninvasive tool for the assessment of cardiac hemodynamics. However, it is subject to limitations that can have important clinical implications, especially in the setting of valve prosthesis. Elevation in mean transvalvular gradient is a finding that has a variety of etiologies. One such etiology is the pressure-recovery (PR) phenomenon, a consequence of stream convergence and energy conversion across a narrowing, which is an artifact of Doppler echocardiographic calculations of valvular flow. The elevated gradient measured with Doppler echocardiography as a result of PR is not present on cardiac catheterization and does not represent true problematic valve hemodynamics. PR should be suspected with an elevated gradient on Doppler echocardiography with normal leaflet motion, especially in the setting of a small proximal aorta. Understanding and awareness of PR are important because PR can lead to overestimation of disease severity in the clinical setting.

Analysis of various techniques of aortic root enlargement

Prosthesis-patient mismatch after aortic valve replacement is associated with increased morbidity and mortality. A myriad of techniques have been described for aortic root enlargement to circumvent this problem. We review the salient techniques with their merits, demerits, and results.

Simple Interrupted Suturing for Aortic Valve Replacement in Patients with Severe Aortic Stenosis

Background

Attaining an adequate effective orifice area (EOA) is definitive goal in aortic valve replacement (AVR). The simple interrupted suture (SIS) technique could be a solution to achieve this goal, but limited data are available in the literature. This study aimed to compare hemodynamic differences between the SIS and non-everting mattress suture (NMS) techniques.

Methods

From our database, 215 patients who underwent AVR for severe aortic stenosis were extracted to form the overall cohort. From March 2015 to November 2016, the SIS technique was used in 79 patients, while the NMS technique was used in 136 patients. Hemodynamic outcomes were evaluated, as detected by transthoracic echocardiography and computed tomography.

Results

There were no significant differences in baseline characteristics between the 2 groups. On immediate postoperative echocardiography, the SIS group showed a significantly wider EOA (1.6±0.4 vs. 1.4±0.5 cm², p=0.007) and a lower mean pressure gradient (PG) (13.3±5.4 vs. 17.0±6.0 mm Hg, p<0.001) than the NMS group. On follow-up echocardiography, the SIS group continued to have a wider EOA (1.6±0.4 vs. 1.4±0.3 cm², p<0.001) and a lower mean PG (11.0±5.1 vs. 14.1±5.5 mm Hg, p<0.001). There was no significant difference in paravalvular leakage.

Conclusion

The SIS technique for AVR was associated with a wider EOA and a lower mean PG. The SIS technique could be a reasonable option for AVR.