Lower Mean Pressure Gradient Research Articles

Comparison of middle-term valve durability between transcatheter aortic valve implantation and surgical aortic valve replacement: an updated systematic review and meta-analysis of RCTs.

This study aims to compare valve durability between transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR). We conducted a systematic review and meta-analysis using data from randomized controlled trials (RCTs). The primary outcome was structural valve deterioration (SVD). Secondary outcomes were bioprosthetic valve failure, reintervention, effective orifice area (EOA), mean pressure gradient, and moderate-severe aortic regurgitation (AR, transvalvular and/or paravalvular). Twenty-five publications from seven RCTs consisting of 7,970 patients were included in the analysis with follow-up ranges of 2-8 years. No significant difference was found between the two groups with regard to SVD [odds ratio (OR) 0.72; 95% CI: 0.25-2.12]. The TAVI group was reported to exhibit a statistically significant higher risk of reintervention (OR 2.03; 95% CI: 1.34-3.05) and a moderate-severe AR (OR 6.54; 95% CI: 3.92-10.91) compared with the SAVR group. A trend toward lower mean pressure gradient in the TAVI group [(mean difference (MD) -1.61; 95% CI: -3.5 to 0.28)] and significant higher EOA (MD 0.20; 95% CI: 0.08-0.31) was noted. The present data indicate that TAVI provides a comparable risk of SVD with favorable hemodynamic profile compared with SAVR. However, the higher risk of significant AR and reintervention was demonstrated. PROSPERO (CRD42022363060).

ADVANTAGES AND DISADVANTAGES OF HEART VALVE PROSTHESES WITH FLEXIBLE SUPPORTING FRAME COMPARED WITH THE CLASSIC STENTED PROSTHESES: EVALUATION OF THE HYDRODYNAMIC INDICATORS OF THE “UNILINE” AND “TIARA” BIOPROSTHESES

HighlightsThe «TiAra» bioprosthetic heart valves have better hemodynamic characteristics, such as higher effective orifice area and a lower mean pressure gradient.The «UniLine» bioprosthetic heart valve demonstrated better closing dynamic, expressed in a smaller regurgitation volume. Aim. To assess hydrodynamic characteristics of the «TiAra» bioprosthetic heart valve with flexible supporting frame compared with the classic stented «UniLine» bioprosthetic aortic valve.Methods. Using the Vivitro Pulse Duplicator (Vivitro Labs, Canada), we simulated the function of the heart via generating pulsatile flow to analyze bioprosthetic heart valves. To comprehensively assess the bioprosthesis function, three valves of each standard size (21, 23, 25 mm) were submitted to hydrodynamic testing, thus making a sample of nine bioprostheses of each model. The article provides the analysis of the effective orifice area, mean pressure gradient, regurgitation volume, and assessment of the statistical sensitivity of the parameters between groups at p = 0.05.Results. The assessment revealed that the «TiAra» bioprosthesis has bigger effective orifice area (p = 0.006) and lower mean pressure gradient (p = 0.02): 1.6–2.2 cm2 and 3.6–6.3 mmHg versus 1.08–1.73 cm2 and 4.8–12.1 mmHg, respectively. The regurgitation volume, however, was lower in the «UniLine» bioprostheses 0.8–4.1 mL/cycle versus 6.2–9.0 mL/cycle (p = 0.0004).Conclusion. Despite the fact that both studied models showed good hydrodynamic performance, the prosthesis with the flexible supporting frame («TiAra») showed better results regarding its effectiveness in vitro via presenting with bigger effective orifice area and lower mean pressure gradient. At the same time, the «UniLine» stented bioprosthesis had lower regurgitation volume, i.e. better closing dynamics.

Impact of aortic annular size and valve type on haemodynamics and clinical outcomes after transcatheter aortic valve implantation

Data on patients with small aortic annuli (SAA) undergoing transcatheter aortic valve implantation (TAVI) are limited. We aim to describe the impact of aortic annular size, particularly SAA and TAVI valve type on valve haemodynamics, durability and clinical outcomes. All patients in National Heart Centre Singapore who underwent transfemoral TAVI for severe symptomatic native aortic stenosis from July 2012 to December 2019 were included. Outcome measures include valve haemodynamics, prosthesis-patient mismatch (PPM), structural valve degeneration (SVD) and mortality. A total of 244 patients were included. The mean Society of Thoracic Surgeons score was 6.22±6.08, with 52.5% patients with small aortic annulus (<23mm), 33.2% patients with medium aortic annulus (23-26mm) and 14.3% patients with large aortic annulus (>26mm). There were more patients with self-expanding valve (SEV) (65.2%) versus balloon-expandable valve (BEV) (34.8%). There were no significant differences in indexed aortic valve area (iAVA), mean pressure gradient (MPG), PPM, SVD or mortality across all aortic annular sizes. However, specific to the SAA group, patients with SEV had larger iAVA (SEV 1.19±0.35cm2/m2 vs BEV 0.88±0.15cm2/m2, P<0.01) and lower MPG (SEV 9.25±4.88 mmHg vs BEV 14.17±4.75 mmHg, P<0.01) at 1 year, without differences in PPM or mortality. Aortic annular size, TAVI valve type and PPM did not predict overall mortality up to 7 years. There was no significant difference in SVD between aortic annular sizes up to 5 years. Valve haemodynamics and durability were similar across the different aortic annular sizes. In the SAA group, SEV had better haemodynamics than BEV at 1 year, but no differences in PPM or mortality. There were no significant differences in mortality between aortic annular sizes, TAVI valve types or PPM.

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

BackgroundAttaining 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.MethodsFrom 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.ResultsThere 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.ConclusionThe 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.

Does the severity of low-gradient aortic stenosis classified by computed tomography-derived aortic valve calcification determine the outcome of patients after transcatheter aortic valve implantation (TAVI)?

Aortic valve calcification (AVC) determined by computed tomography has emerged as a complementary measure of aortic stenosis (AS) severity and as a predictor of adverse events. Thus, AVC can guide further treatment decisions in patients with low-gradient AS (LG-AS). We compared the symptomatic and prognostic outcome of patients with low vs. high AVC after transcatheter aortic valve implantation (TAVI). Patients with an aortic valve area index ≤ 0.6cm2/m2 and a mean pressure gradient (MPG) < 40mmHg were classified as low-flow, low-gradient AS (LFLG-AS; stroke volume index [SVI] ≤ 35ml/m2, left ventricular ejection fraction [LVEF] < 50%, n = 173), paradoxical LFLG-AS (pLFLG-AS, SVI ≤ 35ml/m2, LVEF ≥ 50%, n = 233), or normal-flow, low-gradient AS (NFLG-AS, SVI > 35ml/m2, LVEF ≥ 50%, n = 244); patients with MPG ≥ 40mmHg (n = 1142) served as controls. Patients were further categorized according to published AVC thresholds. Demographic characteristics and cardiovascular risk were not different between patients with high vs. low AVC in any of the subgroups. Patients with low AVC had a lower MPG. Symptom improvement at 30days was observed in the majority of patients but was less pronounced in LFLG-AS patients with low vs. those with high AVC. Kaplan-Meier 1-year survival curves were identical between patients with low and high AVC in all three LG-AS groups. The severity of LG-AS based on AVC has no impact on 1-year prognosis once TAVI has been performed. • Aortic valve calcification (AVC) determined by computed tomography has emerged as a complementary measure of aortic stenosis (AS) severity and is of prognostic value in selected patients. • Patients with inconsistent echocardiographic measures can be classified as having severe or nonsevere AS by the computed tomography-derived AVC score. • The prognostic value of AVC in patients with low-gradient AS is abrogated after correction of afterload by TAVI.

Prevalence, clinical and echocardiographic characteristics of various flow and gradient patterns in mild or moderate aortic stenosis with normal left ventricular ejection fraction

Background/objectivesParadoxical low-flow aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) has only been described in severe AS. Controversy surrounds prognosis and management but no studies have reported this phenomenon in mild or moderate AS. We investigated the prevalence of flow and gradient patterns in this population, characterising their clinical and echocardiographic profile. MethodsConsecutive subjects (n=1362) with isolated AS: mild (n=462, aortic valve area≥1.5cm2, 2.5m/s<aortic jet velocity≤3m/s) or moderate (n=900, 1cm2≤aortic valve area<1.5cm2) and normal LVEF (≥50%) were studied. Subjects with low-flow (stroke volume index<35ml/m2) were identified. Univariate and multivariate analyses were employed to compare the flow and gradient patterns. ResultsIn mild AS, 130 (28%) had low-flow. Lower left ventricular mass index (LVMI) (97.0±28.5vs116.4±2.3g/m2,p<0.001), higher percentage of concentric remodelling (40%vs6%,p<0.001) and hypertrophy (43%vs40%,p<0.001) and lower end-systolic wall stress (ESWS) (57.6±1.60vs67.7±19.6dyn/cm2,p=0.014) were independently associated with low-flow. Similarly, in moderate AS, 297 (33%) had low-flow. Older age (73.4±14.8vs69.5±16.5,p=0.027), lower LVMI (88.6±25.9vs118.0±36.5,p<0.001), higher percentage of concentric remodelling (46%vs8%,p<0.001) and lower ESWS (59.9±18.3vs70.5±19.7,p<0.001) were independently associated with low-flow. Despite moderate AS, most had lower mean pressure gradients, especially subjects with concentric remodelling. In the entire cohort, low-flow patients had more concentric remodelling (43%vs7%,p<0.001) and less eccentric hypertrophy (2%vs27%,p<0.001) compared to normal flow. ConclusionsLow-flow AS with normal LVEF is observed in mild or moderate AS, in up to a third of the cases. These patients had different LV structure compared to normal-flow, with more concentric remodelling. Further studies are warranted.

Homograft Performance in Children After the Ross Operation

The Ross operation may be the ideal aortic valve replacement in pediatric patients. However, reoperations for replacement of the homograft in the pulmonary position are inevitable. This study determined influencing factors for the development of homograft stenosis and regurgitation in pediatric Ross patients. Follow-up echocardiograms of 116 children (86 boys) undergoing Ross operations at a mean age, 9.3 +/- 4.9 years were analyzed using hierarchic multilevel modeling. Mean duration of the echocardiographic follow-up was 5.3 +/- 4.2 years (609 patient-years, 398 examinations). Median homograft diameter z value was 0.3 (range -2.2 to +7.3). Mean homograft pressure gradient at implantation was 5.0 mm Hg with a significant increase of 4.2 mm Hg/y (p < 0.001) within the first 2 years and a steady state thereafter. Older donor age was significantly associated with lower mean pressure gradient at implantation (p = 0.037). Larger z value had no significant influence on the annual increase of pressure gradient (p = 0.87). Mean grade of regurgitation at implantation was 0.9, without significant annual increase (0.02 grade/y, (p = = 0.32). Older recipient (p = 0.005) and donor age (p < 0.0001) were significantly associated with lower mean regurgitation at implantation. Larger z value was associated with a higher annual increase of regurgitation (p = 0.014). Relevant midterm homograft regurgitation is rare in children after the Ross operation. However, a significant annual increase occurs in the pressure gradient that cannot be influenced by larger graft size. Homograft oversizing may lead to a higher annual increase of regurgitation.

Chordae Replacement Versus Resection for Repair of Isolated Posterior Mitral Leaflet Prolapse: À Ègalité

Mitral valve (MV) repair for posterior mitral leaflet (PML) prolapse has proven excellent results. The loop technique, which involves insertion of polytetrafluoroethylene neochordae while preserving the native PML tissue, was developed to facilitate MV repair through a minimally invasive approach. The aim of this study was to assess the medium-term results of the loop technique in comparison with the widely adopted leaflet resection technique for repair of isolated PML prolapse. Between March 1999 and January 2008, a total of 1,708 patients underwent minimally invasive MV repair. Six hundred and seventy patients (39.2%) had isolated PML prolapse and were treated with either the loop technique (n = 317) or the leaflet resection (n = 353) technique, according to surgeon preference. Mean follow-up time was 2.8 +/- 2.2 years, and follow-up was 99% complete. Early postoperative echocardiography showed a significantly larger mitral orifice area (3.3 +/- 0.3 cm(2) versus 3.0 +/- 0.8 cm(2), p < 0.001) and lower mean pressure gradient (2.7 +/- 1.7 mm Hg versus 3.1 +/- 1.7 mm Hg, p = 0.03) after implantation of loops. Other perioperative outcomes were similar for the two groups of patients. Freedom from reoperation at 5 years was significantly higher after the loop technique (98.7%, 95% confidence interval [CI]: 96.7% to 99.5%) when compared with leaflet resection (93.9%, 95% CI: 90.7% to 96.1%, log-rank p = 0.005). Cox regression analysis revealed that implantation of a flexible, incomplete band was an independent predictor of reoperation (hazard ratio 6.2, 95% CI: 1.3 to 110.7), whereas use of leaflet resection had a nonsignificant trend toward an increased reoperation rate (hazard ratio 2.6, 95% CI: 0.9 to 9.1). Reoperation for excessive systolic anterior motion did not occur in any loop patient. Both the loop technique and conventional leaflet resection yield excellent results for repair of isolated PML prolapse. The technical ease of performing the loop technique through a minimally invasive approach, however, makes this method a particularly valuable alternative for MV repair surgery.

Angina pectoris and coronary artery disease in patients with severe aortic valvular disease

We studied the clinical, hemodynamic, and angiographic findings of 90 consecutive patients with significant symptomatic aortic valve disease, 40 years of age or older, to evaluate the prevalence of angina pectoris in relation to coronary artery disease and the effect upon cardiac function. The prevalence of chest pain was 66% (typical angina, 39%; atypical chest pain, 27%), and the prevalence of coronary artery disease was 39%. The prevalence of coronary artery disease in patients with typical angina was 77%, in contrast to 25% in patients with atypical chest pain ( P = 0.001) . Only two of the 35 patients (6%) with coronary artery disease were free of chest pain. Although the incidence of coronary artery disease in patients with aortic stenosis was slightly higher than in patients with aortic regurgitation or aortic stenosis-aortic regurgitation, it was not statistically significant. Patients with aortic regurgitation and coronary artery disease had significantly lower ejection fraction than patients with aortic stenosis and coronary artery disease. There were no significant differences between ejection fraction in patients without coronary artery disease in the different groups. Patients with aortic stenosis and coronary artery disease tend to have lower mean pressure gradients than those without coronary artery disease. Patients with coronary artery disease in aortic regurgitation and aortic stenosis-aortic regurgitation tend to have higher left ventricular end-diastolic pressure. This study indicates that although patients with aortic valve disease and typical angina are most likely to have associated coronary artery disease, it is not possible to predict this disorder with accuracy by means of clinical or hemodynamic findings. Since the presence or absence of coronary artery disease in patients undergoing aortic valve replacement has prognostic and therapeutic significance, we recommend that coronary arteriography be performed in all patients with significant aortic valve disease undergoing cardiac catheterization when they present with any form of chest pain, or in patients over the age of 40 years even if no chest pain is present. Coronary arteriography would also rule out anomalous aortic origin of the coronary arteries.