Increase In Valve Area Research Articles

Biointegration and Growth of Porcine Valved Pulmonary Conduits in a Sheep Model

As there is currently no suitable valved pulmonary conduit for small children, porcine conduits treated by the L-Hydro process were implanted into 9 newborn lambs to investigate growth potential. Of the 8 survivors, 7 were kept alive for 12 months after implantation. The diameter of the conduit and gradient across the valve were evaluated at surgery and at 3 and 9 months postoperatively using bidirectional echocardiographic and angiographic methods. After sacrifice, histological and radiological analyses were performed. The mean weight of the animals was 4.2 +/- 1.1 kg at implantation and 43.1 +/- 6.2 kg at sacrifice. There was a significant increase in mean valve area from 139.9 +/- 18.0 mm2 at implantation to 443.5 +/- 89.2 mm2 at 12 months. Pre-sacrifice angiography showed no transvalvular gradient, and radiographic analysis did not reveal significant conduit wall or leaflet calcification in any of the animals. Histological examination of the grafts demonstrated total integration, with native-like intact valve leaflets. Thus functional evaluation, echocardiography, and histology demonstrated growth of the grafts with completely endothelialized and apparently normal pulmonary valve leaflets without calcification.

Transcatheter aortic valve implantation in the operating room: early experience

Aortic stenosis is the most common valvular heart disease in the Western world and the proportion of patients unsuitable for conventional surgery is increasing as a result of aging and comorbidities. We report our early experience with transcatheter aortic valve implantation in high-risk patients with severe symptomatic aortic stenosis. Transcatheter Edwards-SAPIEN valve implantation was attempted in 22 patients (80 +/- 5 years) in whom surgical risk was deemed excessive because of older age, poor left ventricular function, comorbidities, or all. A retrograde transarterial approach was used in 15 cases. In seven cases, valve implantation was performed by transapical approach because of aortic or iliac artery tortuosity, or both, and stenosis. All procedures were performed without cardiopulmonary bypass. Rapid ventricular pacing was used to reduce cardiac output while delivering balloon-expandable prosthesis. One patient died because of aortic dissection during early catheterization maneuvers. In the remaining patients, procedural success was achieved in all cases. Successful valve replacement was associated with an increase in transthoracic echocardiographic valve area from 0.65 +/- 0.14 to 2.2 +/- 0.4 cm2 and significant improvement in clinical condition. During the course of this experience, we encountered three (13.6%) cases of vascular complications related to transcatheter aortic valve implantation procedures. The present study confirms the excellent hemodynamic performances of the transcatheter-implanted aortic prosthesis, with both transarterial and transapical approaches, in inoperable candidates with end-stage aortic stenosis. With progressive improvement in patient selection, techniques, equipment, and operator endovascular skills, vascular complications can decline further.

Early echocardiographic evaluation following percutaneous implantation with the self-expanding CoreValve ReValving System aortic valve bioprosthesis

Although safety and feasibility studies have been published, there are few reports dedicated to the echocardiographic evaluation of patients following percutaneous aortic valve replacement (PAVR). This report describes the early echocardiographic evaluation of patients undergoing PAVR with the CoreValve Revalving System. The population consisted of 33 consecutive patients with aortic stenosis who underwent successful PAVR. Echocardiograms were performed pre-treatment (123+/-110 days prior), post-treatment (6+/-2 days) and post-discharge (80+/-64 days). Aortic valve function and left ventricular dimensions, systolic and diastolic function were assessed pre- and post-implantation. The mean age was 81+/-7 years and the mean Logistic Euroscore was 20+/-12. Following PAVR, the mean transaortic valve gradient decreased (46+/-16 mmHg pre-treatment vs. 12+/-7 mmHg post-treatment vs. 9+/-5 mmHg post-discharge, p<0.001) and the mean effective orifice area increased (0.75+/-0.23 cm2 pre-treatment vs. 1.97+/-0.85 cm2 post-treatment vs. 1.72+/-0.45 cm2 post-discharge, p<0.001). There was no significant change in mean ejection fraction (41+/-12% pre-treatment vs. 46+/-15% post-treatment vs. 44+/-13% post-discharge, p=0.44). Approximately two-thirds of patients had no change in diastolic function at follow-up. Following implantation, there was a sustained decrease in aortic valve gradient and increase in aortic valve area. In addition, the mean ejection fraction did not change significantly and in the majority of patients, diastolic function was unchanged.

Retrograde Transarterial Implantation of a Nonmetallic Aortic Valve Prosthesis in High–Surgical-Risk Patients With Severe Aortic Stenosis

Background— To assess the feasibility and safety of retrograde transarterial implantation of a novel nonmetallic aortic valve prosthesis (Direct Flow Medical Inc, Santa Rosa, Calif), a prospective single-center study was performed in patients with severe aortic stenosis at high risk for open-heart surgery. Methods and Results— Fifteen patients (intention-to-treat cohort) with an aortic valve area ≤0.8 cm 2 , a ≥35-mm Hg mean transvalvular pressure gradient, and a logistic EuroSCORE ≥20% were enrolled. Percutaneous aortic valve replacement was performed with the patient under general anesthesia. Hemodynamic parameters were assessed before and after implantation by transesophageal echocardiography. Clinical follow-up and transthoracic echocardiographic assessment were obtained at 30 days. Procedural success was achieved in 12 patients (80%). Surgical conversion became necessary at day 2 in 1 patient; 11 patients (73%) were discharged with a permanent implant. In these patients, implantation resulted acutely in a significant increase in aortic valve area (median, 1.64 [interquartile range, 1.27 to 1.74] versus 0.60 [0.46 to 0.69] cm 2 ; P =0.0033) and a concomitant reduction in the mean pressure gradient (14.0 [13.2 to 16.5] versus 54.0 [43.2 to 59.8] mm Hg; P =0.0033). At 30 days, 1 cardiac death (6.7%; 95% CI, 0.2% to 32.0%) and 1 major stroke were observed. The 10 surviving patients with a permanent implant showed marked hemodynamic and clinical improvement at this time point. Conclusions— In this small series of patients, percutaneous implantation of the Direct Flow Medical aortic valve prosthesis in high–surgical-risk patients was feasible and associated with a reasonably low safety profile.

Delayed Improvement in Valve Hemodynamic Performance After Percutaneous Pulmonary Valve Implantation

We report the case of a 21-year-old woman with a severely stenotic pulmonary homograft who underwent percutaneous pulmonary valve implantation, with no significant change in transvalvular gradient within the 24 hours after the procedure. Major improvement in hemodynamic valve performance of more than 60% decrease in transvalvular gradient and more than 30% increase in pulmonary valve area was observed 3 months after the procedure, showing that hemodynamic improvement can occur late after pulmonary valve implantation. An echocardiogram after 3 months should be done before concluding the procedure failed and that reintervention is necessary.

Percutaneous mitral valvuloplasty in patients with low cardiac output at high surgical risk

Among 1146 patients undergoing percutaneous mitral valvuloplasty for symptomatic mitral stenosis, 8 (4 men and women) were at high risk for surgery on the basis of the New York Heart Association functional class IV ( n = 8), severe pulmonary hypertension ( n = 5). All these patients aged 30 ±23.6 years had signs of right heart failure, high echocardiographic score (9.6 ± 3.6) and low mitral valve area (0.50 ± 0.19 cm 2). The procedure resulted in an increase in mitral valve area (1.55 ± 0.17 cm 2) with a concomitant reduction in pulmonary artery systolic pressure (58.7 ± 9.9 mm Hg) and decrease in tricuspid regurgitation. At follow-up (mean 14 ± 3 months), one patient with renal failure… presented with a mitral restenosis is scheduled for mitral valve replacement, two patients with severe tricuspid regurgitation required tricuspid annuloplasty. In conclusion, percutaneous mitral valvuloplasty is feasible and safe in patients at high surgical risk and can be considered as an acceptable alternative to surgery.

Percutaneous Transarterial Aortic Valve Replacement in Selected High-Risk Patients With Aortic Stenosis

Percutaneous aortic valve replacement represents an endovascular alternative to conventional open heart surgery without the need for sternotomy, aortotomy, or cardiopulmonary bypass. Transcatheter implantation of a balloon-expandable stent valve using a femoral arterial approach was attempted in 50 symptomatic patients with severe aortic stenosis in whom there was a consensus that the risks of conventional open heart surgery were very high. Valve implantation was successful in 86% of patients. Intraprocedural mortality was 2%. Discharge home occurred at a median of 5 days (interquartile range, 4 to 13). Mortality at 30 days was 12% in patients in whom the logistic European System for Cardiac Operative Risk Evaluation risk score was 28%. With experience, procedural success increased from 76% in the first 25 patients to 96% in the second 25 (P=0.10), and 30-day mortality fell from 16% to 8% (P=0.67). Successful valve replacement was associated with an increase in echocardiographic valve area from 0.6+/-0.2 to 1.7+/-0.4 cm2. Mild paravalvular regurgitation was common but was well tolerated. After valve insertion, there was a significant improvement in left ventricular ejection fraction (P<0.0001), mitral regurgitation (P=0.01), and functional class (P<0.0001). Improvement was maintained at 1 year. Structural valve deterioration was not observed with a median follow-up of 359 days. Percutaneous valve replacement may be an alternative to conventional open heart surgery in selected high-risk patients with severe symptomatic aortic stenosis.

Rest and Dobutamine stress echocardiography in the evaluation of mid-term results of mitral valve repair in Barlow's disease

BackgroundSurgical "anatomical" repair is the most frequent technique used to correct mitral regurgitation due to severe myxomatous valve disease. Debate, however, persists on the efficacy of this technique, as well as on the durability of the repaired valve, and on its functioning and hemodynamics under stress conditions. Thus, a basal and Dobutamine echocardiographic (DSE) study was carried out to evaluate these parameters at mid-term follow-up.Methods and ResultsTwenty patients selected for the study (12 men and 8 women, mean age 60 ± 9 years) underwent pre- and post-operative transthoracic echocardiography (TTE) and intra-operative transesophageal echocardiography (TEE). At mid-term follow-up (20 ± 5 months) all patients underwent rest TTE and DSE (3 min. dose increments up to 40 microg/Kg/min protocol). Pre-discharge and one-month TTE showed absence of MR in 11 pts., trivial or mild MR in 9 pts. and normal mitral valve area and gradients. Mid-term TTE showed decrease in left atrial and ventricular dimension, in pulmonary artery pressure (sPAP) and grade of MR. During DSE a significant increase in mitral valve area, maximum and mean gradients, sPAP, heart rate and cardiac output and a decrease in systolic annular diameter and left ventricular volume were found; in 6 pts. a transient left ventricular outflow tract obstruction was observed.ConclusionBasal and Dobutamine stress echocardiography proved to be valuable tools for evaluation of mid-term results of mitral valve repair. In our study population, the surgical technique employed had a favourable impact on several cardiac parameters, evaluated by these methods.

Issue Highlights

HomeCirculationVol. 114, No. 6Issue Highlights Free AccessIn BriefPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessIn BriefPDF/EPUBIssue Highlights Originally published8 Aug 2006https://doi.org/10.1161/circ.114.6.529Circulation. 2006;114:529PERFORMANCE OF TOP-RANKED HEART CARE HOSPITALS ON EVIDENCE-BASED PROCESS MEASURES, by Williams et al.The US News & World Report annual publication of “America’s Best Hospitals” attracts considerable attention each year, but the validity of the ranking is not known. Investigators from the Joint Commission on Accreditation of Healthcare Organizations sought to determine how ranked and unranked hospitals compared on the publicly reported quality-of-care measures for patients admitted with acute myocardial infarction and heart failure. Williams and colleagues compare 41 ranked hospitals and 733 unranked hospitals with respect to their performance on 6 acute myocardial infarction and 4 heart failure process measures. The study determined if the ranked hospitals, in aggregate, performed better and then investigated how well the ranking discriminated between hospitals by their performance. The results provide important information about the value of this popular system. See p 558.INHIBITION OF UROKINASE-TYPE PLASMINOGEN ACTIVATOR OR MATRIX METALLOPROTEINASES PREVENTS CARDIAC INJURY AND DYSFUNCTION DURING VIRAL MYOCARDITIS, by Heymans et al.The mechanisms by which viral myocarditis leads to cardiac injury and failure are not fully understood. In this issue of Circulation, Heymans et al examined the role of the proteinases urokinase-type plasminogen activator (uPA) and matrix metalloproteinases (MMPs) in mediating cardiac inflammation, injury, and subsequent failure during coxsackievirus-B3 induced myocarditis. The expression and activity of uPA and MMP-9 was increased in mice 7 days after infection with coxsackievirus-B3. In mice with deletion of uPA or inhibition of MMPs by adenoviral gene overexpression of tissue inhibitor of metalloproteinases-1, there was decreased cardiac inflammation and reduced myocardial necrosis, decreased cardiac fibrosis at 35 days, and prevention of cardiac dilatation and dysfunction. These data implicate these proteinases in the pathogenesis of viral myocarditis and thereby raise the possibility of new therapeutic interventions. See p 565.TRANSAPICAL TRANSCATHETER AORTIC VALVE IMPLANTATION IN HUMANS: INITIAL CLINICAL EXPERIENCE, by Lichtenstein et al.Surgical aortic valve replacement has been the standard of care for symptomatic patients with severe aortic stenosis. Recently, percutaneous transfemoral aortic valve replacement has been proposed. In this study by Lichtenstein et al, a new technique is reported, in which surgical exposure of the left ventricular apex allows aortic valve replacement of a pericardial valve prosthesis via a direct left ventricular apical puncture. The initial experience in 7 patients is described. All patients were considered too high risk for conventional surgery. The procedure was successful in all with an increase in aortic valve area from 0.7±0.1 cm2 to 1.8±0.8 cm2. At an average of 87 days follow-up, all patients were alive and doing well. This initial experience suggests that aortic valve replacement via direct left ventricular access without cardiopulmonary bypass is feasible. See p 591.Visit http://circ.ahajournals.org:Images in Cardiovascular MedicinePercutaneous Transluminal Angioplasty for Treatment of Critical Hand Ischemia. See p e232. Download figureDownload PowerPointGastroesophageal Reflux Facilitates Esophageal Imaging During Pulmonary Vein Ablation. See p e235.Hybrid Cardiac Single Photon Emission Computed Tomography/Computed Tomography Imaging With Myocardial Perfusion Single Photon Emission Computed Tomography and Multidetector Computed Tomography Coronary Angiography for the Assessment of Unstable Angina Pectoris After Coronary Artery Bypass Grafting. See p e237.CorrespondenceSee p e240. Previous Back to top Next FiguresReferencesRelatedDetailsCited ByLanger F, Kunihara T, Hell K, Schramm R, Schmidt K, Aicher D, Kindermann M and Schäfers H (2009) RING+STRING, Circulation, 120:11_suppl_1, (S85-S91), Online publication date: 15-Sep-2009.Sack S, Kahlert P, Bilodeau L, Pièrard L, Lancellotti P, Legrand V, Bartunek J, Vanderheyden M, Hoffmann R, Schauerte P, Shiota T, Marks D, Erbel R and Ellis S (2009) Percutaneous Transvenous Mitral Annuloplasty, Circulation: Cardiovascular Interventions, 2:4, (277-284), Online publication date: 1-Aug-2009. Gelsomino S, Lorusso R, Rostagno C, Caciolli S, Bille G, De Cicco G, Romagnoli S, Porciani C, Stefano P and Gensini G (2008) Prognostic value of Doppler-derived mitral deceleration time on left ventricular reverse remodelling after undersized mitral annuloplasty, European Journal of Echocardiography, 10.1093/ejechocard/jen034, 9:5, (631-640) August 8, 2006Vol 114, Issue 6 Advertisement Article InformationMetrics https://doi.org/10.1161/circ.114.6.529 Originally publishedAugust 8, 2006 PDF download Advertisement

Immediate and Long-Term Follow-Up of Percutaneous Balloon Mitral Valvuloplasty in Pregnant Patients With Rheumatic Mitral Stenosis

Percutaneous mitral balloon valvuloplasty (PMV) can be performed during pregnancy without significant maternal risk or fetal morbidity or mortality. However, little is known about long-term follow-up results after PMV in populations of pregnant women. Thus, the present study was undertaken to determine the immediate and long-term outcomes after PMV in a large cohort of pregnant patients with severe mitral stenosis. The patient population consisted of 71 consecutive pregnant women with severe rheumatic mitral stenosis admitted to the hospital with severe congestive heart failure (New York Heart Association class III and IV) for PMV. All patients underwent clinical and obstetric evaluations, electrocardiography, and 2-dimensional and Doppler echocardiography. PMV was successful in all patients, resulting in a significant increase in mitral valve area from 0.9 +/- 0.2 to 2.0 +/- 0.3 cm2 (p <0.001). At the end of pregnancy, 98% of the patients were in New York Heart Association functional class I or II. At a mean follow-up of 44 +/- 31 months, the total event-free survival rate was 54%. The mean gestational age at delivery time was 38 +/- 1 weeks. Preterm deliveries occurred in 9 patients (13%), including 2 twin pregnancies. The remaining 66 of 75 newborns (88%) had normal weight (mean 2.8 +/- 0.6 kg) at delivery. At long-term follow-up of 44 +/- 31 months after birth, the 66 children exhibited normal growth and development and did not show any clinical abnormalities. In conclusion, PMV is safe and effective, has a low morbidity and mortality rate for the mother and the fetus, and has favorable long-term results in pregnant women with rheumatic mitral stenosis in New York Heart Association functional class III or IV.

Proceedings of the TCT: Balloon Aortic Valvuloplasty Appropriate for Elderly Valve Patients

Balloon aortic valvuloplasty (BAV) has been a highly successful therapy for children and young adults with aortic valve stenosis, resulting in both symptomatic improvement and durable increases in the aortic valve area. Despite enthusiasm for BAV in older adult patients with aortic valve stenosis in the mid-1980s, the therapy has had disappointing medium- and long-term outcomes. Survival of patients with aortic valve stenosis does not increase with BAV, and restenosis occurs in the vast majority of patients within 6-24 months after therapy. Despite these limitations, most patients are symptomatically improved for a year or more. BAV remains an effective palliative therapy for selected patients.

Effect of the increase in valve area after aortic valve replacement with a 19-mm aortic valve prosthesis on left ventricular mass regression in patients with pure aortic stenosis

Although patients with aortic stenosis, who receive 19-mm valves, are at high risk for prosthesis-patient mismatch, most of them show a significant left ventricular mass (LVM) regression postoperatively. The aim of this study was to identify factors predicting postoperative relative LVM regression in this subgroup of patients. A population of 44 patients operated on for pure aortic stenosis and receiving a 19-mm valve was studied by echocardiography at 1.4 +/- 0.5 years postoperatively. The mean relative LVM regression was -19.3 +/- 18.9%, the mean gradient drop was -31.6 +/- 13.3 mmHg, and the mean Delta increase in aortic area index (postoperative aortic area index minus preoperative aortic area index) was 0.30 +/- 0.14 cm/m. Thirty-two patients had an indexed effective orifice area of less than 0.8 cm/m. At multivariate analysis (r = 0.63; r = 40%; P < 0.0001) preoperative LVM (P = 0.006), hypertension (P = 0.018) and Delta aortic area index (P = 0.049) were independent predictors of relative LVM regression. Our study shows that, at least 1 year postoperatively, in patients receiving a 19-mm valve, LVM regression is influenced by several parameters, in particular preoperative LVM, hypertension and the magnitude of the increase in aortic area.

Early Effects of Percutaneous Mitral Valvuloplasty on Left Atrial Mechanical Functions

It has been suggested that successful percutaneous balloon mitral valvuloplasty (PMV) decreases the intensity of spontaneous left atrial contrast, reduces the size of the left atrium, and improves left atrial function in patient with mitral stenosis. However, left atrial mechanical functions immediately after PMV have not been extensively evaluated yet. The aim of this study was to evaluate the effects of PMV on left atrial mechanical functions. Twenty patients with critical mitral stenosis who have normal sinus rhythm (male/female: 4 to 16; mean age: 33 +/- 8 years) were included in the study. Left atrial mechanical functions were evaluated before and after PMV, including left atrial passive emptying volume, LA passive emptying fraction, conduit volume, left ventricular stroke volume, LA active emptying volume, LA active emptying fraction, LA total emptying volume and LA total emptying fraction. PMV resulted in a significant increase in the mitral valve area (p < 0.001) and a substantial reduction in the mean transmitral pressure gradient (p < 0.001) as well as LA diameter (p < 0.002). LA maximal volume, minimal volume and atrial presystolic volumes were significantly decreased after PMV (p: 0.001; p: 0.002; p: 0.001, respectively). The conduit volume was increased and LA total emptying volume was decreased after PMV (p: 0.014; p: 0.035). The other left atrial volumes were not altered after PMV. The early increase in conduit volume and the decrease in left atrial presystolic volume indicate that PMV has favorable effects on atrial reservoir and conduit functions. PMV therefore improves atrial mechanic functions.

Left Atrial Appendage Function Analyzed by Tissue Doppler Imaging in Mitral Stenosis: Effect of Afterload Reduction after Mitral Valve Commissurotomy

This study sought to investigate the relative load dependence of left atrial appendage (LAA) tissue Doppler velocities in patients with mitral stenosis after percutaneous mechanical mitral commissurotomy (PMMC). LAA tissue Doppler velocities were obtained in 34 patients with mitral stenosis (20 with sinus rhythm and 14 with atrial fibrillation) before and after PMMC by transesophageal echocardiography. Standard ultrasound studies were also performed for mitral valve orifice area, transmitral pressure gradient, and LAA blood flow velocity measurements. PMMC resulted in a significant increase in mitral valve area (P < .001) and decrease in mean transmitral pressure gradient (P < .001). LAA tissue Doppler velocities consisted of a triphasic velocity profile: SLAA and ELAA occurring during left ventricular contraction and relaxation, respectively, and ALAA occurring after the atrial contraction. After PMMC, ELAA and ALAA velocities consistently increased (4.8 +/- 1.2 to 7.9 +/- 2.6 cm/sec [P < .001] and 6.6 +/- 2.9 to 8.1 +/- 4.2 cm/sec [P < .05], respectively). The mean transmitral pressure gradient was significantly correlated with ALAA before and after PMMC (r = .65). In mitral stenosis, tissue Doppler velocities illustrated improvement of regional LA function after PMMC, in relation to decreased transmitral pressure gradient.

Mitral Valvuloplasty by Inoue Balloon Under Transthoracic Echocardiographic Guidance

Mitral valvuloplasty traditionally performed under fluoroscopic guidance has emerged as an effective nonsurgical technique for the treatment of symptomatic patients with mitral stenosis. We undertook a study to evaluate the feasibility of performing valvuloplasty by the Inoue balloon solely under transthoracic echocardiographic (TTE) guidance with the backup of transesophaeal echocardiography (TEE) and fluoroscopy. Between September 2003 and July 2004, mitral valvuloplasty using the Inoue balloon was performed solely under TTE guidance in the catheterization laboratory with backup of fluoroscopy and TEE in 75 patients (52 female patients, including 18 who were pregnant, and 23 male patients) with symptomatic mitral stenosis (New York Heart Association class II-IV) with satisfactory TTE window and valve morphology suitable for valvuloplasty. The procedure was technically successful (no requirement of TEE or fluoroscopy) in 68 patients (89%). TEE was required for septal puncture in 3 patients whereas fluoroscopic assistance was required to complete the procedure in 4 patients. Procedural success after valvuloplasty (doubling of mitral valve area or mean gradient across mitral valve < 5 mm Hg in absence of complications like severe mitral regurgitation or tamponade) was achieved in 70 patients. There was an increase in mean mitral valve area as assessed echocardiographically from 0.84 +/- 0.16 cm2 to 1.7 +/- 0.27 cm2 with decrease in mean diastolic gradient from 27.2 +/- 8.4 mm Hg (18-36 mm Hg) to 5.2 +/- 4.1 mm Hg (3-14 mm Hg). The mean procedure time was 27.2 +/- 8.4 minutes (15-45 minutes). Mild mitral regurgitation appeared or increased in severity to moderate degree as assessed by color Doppler during the procedure in 11 patients (14.6%) but no patient developed severe mitral regurgitation. No patient had cardiac tamponade as puncture of the septum under TTE guidance prevents inadvertent puncture of the aorta, coronary sinus, inferior vena cava, and right atrial and left atrial wall that sometimes occurs during septal puncture under fluoroscopic guidance. Balloon mitral valvuloplasty under sole TTE guidance is safe and feasible in experienced hands.

Impact of the Improvement of Valve Area Achieved With Aortic Valve Replacement on the Regression of Left Ventricular Hypertrophy in Patients With Pure Aortic Stenosis

Previous studies have reported that patient-prosthesis mismatch may be associated with lesser regression of left ventricular hypertrophy. However, among the patients with mismatch, the extent of left ventricular mass regression varied markedly from one patient to another, and we hypothesized that it could be related to the magnitude of the increase in valve area achieved with aortic valve replacement. Our aim was to examine the relationship between the improvement in valve effective orifice area obtained with aortic valve replacement and the extent of postoperative left ventricular mass regression in patients with patient-prosthesis mismatch. Preoperative and postoperative measurements of valve effective orifice area, transvalvular pressure gradient, and left ventricular mass were obtained by Doppler echocardiography in 111 patients with pure aortic stenosis who were found to have patient-prosthesis mismatch based on an indexed effective orifice area of 0.8 cm2/m2 or less after operation. On average, the valve effective orifice area increased by 0.45 +/- 0.24 cm2/m2 with operation, and mean transvalvular pressure gradients decreased by -31.6 +/- 13.5 mm Hg. The absolute and relative differences between preoperative and postoperative left ventricular mass were -28 +/- 30 g and -17% +/- 18%, respectively. In multivariate analysis, higher preoperative left ventricular mass (p < 0.0001) and larger increase in indexed valve effective orifice area with operation (p = 0.019) were independently associated with greater left ventricular mass regression. This study shows that in patients with patient-prosthesis mismatch, the degree of left ventricular mass regression is influenced by the increase in valve effective orifice area achieved by aortic valve replacement.

INVITED COMMENTARY

The issue of prosthesis-patient mismatch (PPM) still generates much controversy with regard to its clinical relevance and in particular with regard to its effects on left ventricular (LV) mass regression after operation. Whereas some authors have found that the persistence of PPM results in lesser regression of left ventricular hypertrophy (LVH), others have reported that patients with PPM and/or small prostheses could exhibit significant reductions in LV mass and on this basis, have concluded that PPM was not a relevant issue. The article by Tasca and colleagues is refreshing in adopting an approach to this problem and it is particularly instructive in explaining some of the apparent discrepancies observed in previous studies. Indeed, these authors found that patients with PPM nonetheless exhibit LV mass regression after operation but that the extent of such regression varies considerably from one patient to the other and can be largely related to the extent of valve area increase after operation. Their analysis also underlines the following important pathophysiological concepts: (1) Even in the presence of PPM, surgery normally results in improved hemodynamics, the extent of which can be quite important; (2) based on their previous as well as present observations, a more optimal result can be expected if PPM is completely avoided; (3) in analyzing the results, it is important to remember that the relationship between gradients and the indexed effective orifice area (EOA) is curvilinear and that the implications for a given patient will be directly related to his original and final positions on the indexed EOA-gradient curve. Much of the controversy surrounding this topic can be related to confounding variables, which have included the choice of the wrong factor to identify PPM (indexed geometric area instead of indexed EOA) [1Dumesnil J.G. Pibarot P. Prosthesis size and prosthesis-patient size are unrelated to prosthesis-patient mismatch.J Thorac Cardiovasc Surg. 2004; 127 (Letter to the Editor).: 1852Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar], and dichotomizing between patients with and without PPM instead of considering the indexed EOA as a continuous variable that can be used to quantify the degree of severity of PPM. The study of Tasca and colleagues sets the record straight in this regard. Also, it reminds us that the calculation of the indexed EAO before operation can easily be used to predict postoperative results, orient clinical judgment, and prevent the occurrence of PPM.

Retrograde percutaneous aortic valve implantation for critical aortic stenosis

Recently, a prosthetic aortic valve has been implanted percutaneously in several patients using an antegrade transseptal approach. This has been shown to be feasible and associated with dramatic hemodynamic improvement. We report a retrograde implantation of a percutaneous heart valve (PHV) in an 84-year-old man with critical aortic stenosis and refractory congestive heart failure after difficulties encountered with an initial antegrade approach. While attempting antegrade transseptal implantation of a PHV, the anterior leaflet of the mitral valve was tethered by the guidewire resulting in severe mitral regurgitation and pulseless electrical activity. Cardiac resuscitation was successful. Utilizing a retrograde approach, the PHV was successfully implanted in a stable position below the coronary ostia and well above the mitral valve leaflets. The aortic valve area increased from 0.55 to 1.7 cm2 with only mild paravalvular aortic regurgitation. Despite marked improvement in aortic valve function, the patient died secondary to guidewire-induced mitral valve anterior leaflet laceration, severe mitral regurgitation, and cardiogenic shock. Retrograde implantation of a PHV can be successfully performed with substantial increase in aortic valve area and an acceptable degree of aortic regurgitation. Although the retrograde approach may be associated with greater risk of vascular access site complications, it may be considerably safer by avoiding potential guidewire injury to the mitral valve. Further refinements in technique may establish the retrograde approach as the preferred means of PHV implantation in nonsurgical patients with critical aortic stenosis.

Percutaneous balloon aortic valvuloplasty: Antegrade transseptal vs. conventional retrograde transarterial approach

Percutaneous balloon aortic valvuloplasty (BAV) has been limited predominantly to a palliative treatment for poor surgical candidates with critical aortic stenosis and multiple high-risk or comorbid conditions. The most commonly used technique for BAV is the retrograde approach, in which the balloon is passed via the femoral artery using 12-14 Fr sheaths. We compared an antegrade transseptal approach using the Inoue balloon vs. the retrograde transarterial approach using conventional balloons. The antegrade group had an improved acute hemodynamic outcome, including 20% additional increase of aortic valve area and 20% greater reduction of transaortic valve gradient compared to the retrograde approach. Preclosure with the Perclose device was used for the 14 Fr venous access sites, resulting in immediate hemostasis, minimizing the need for transfusion, and diminishing the period of bed rest. The improved acute efficacy and relative ease of venous access for the antegrade approach facilitate BAV by eliminating the need for large-caliber arterial access sheaths. The antegrade approach also incorporates technical elements necessary for percutaneous aortic valve replacement and may have expanded applications as an adjunct to this developing therapy. The impact of improved acute results on the long-term clinical outcome for this patient group will require further study.

Acute Improvement in Global and Regional Left Ventricular Systolic Function After Percutaneous Heart Valve Implantation in Patients With Symptomatic Aortic Stenosis

The newly developed percutaneous heart valve (PHV) implantation technique decreases transaortic pressure gradient in patients with aortic stenosis. PHV replacement effects on left ventricular (LV) global and regional systolic function are currently unknown. Eight patients with severe aortic stenosis had 2D echocardiography at baseline and 24 hours after PHV implantation to evaluate changes in LV volume and LV ejection fraction. Regional function, ie, both peak systolic anterior and posterior wall tissue velocity, as well as strain and strain rate imaging, were measured by tissue Doppler imaging from a short-axis view. At 24 hours, a significant reduction in transaortic mean pressure gradient (from 46+/-15 to 8+/-3 mm Hg; P<0.0001) was accompanied by an increase in aortic valve area (from 0.59+/-0.11 to 1.69+/-0.11 cm2; P<0.0001). LV end-diastolic volume remained unchanged (102+/-36 to 101+/-12 mL; P=NS), whereas LV ejection fraction increased (48+/-18% to 57+/-12%; P<0.01). Improvement in posterior wall displacement (posterior wall tissue velocity increased from 2.2+/-0.5 to 4.4+/-1.0 cm/s(-1); P=0.0003) and deformation (strain rate imaging increased from 1.0+/-0.3 to 1.9+/-0.7 s(-1), P=0.009, and strain increased from 11+/-5% to 17+/-9%; P=0.02) were observed. Immediately after PHV replacement, improvement of LV global and regional systolic function was evidenced by tissue Doppler imaging.