Use of Hancock porcine xenografts in children and adolescents

Between January 1,1974 and December 31,1978,47 xenografts (8 aortic, 28 mitral, 4 tricuspid, 3 left atrioventricular valve in I-transposition of the great arteries and 3 aortic-mitral) were implanted in 44 patients, aged 10/12 to 20 5/12 years (median 12 2/12). All eight patients with aortic valve replacement survived and were followed up for 22.5 ± 10.4 months (mean ± standard error of the mean). At postoperative cardiac catheterization in three patients, the peak systolic ejection gradient ranged between 24 and 38 mm Hg and the valve area index between 0.71 and 1.15 cm²/m². Among 26 patients who underwent mitral valve replacement, 5 died operatively and 2 died 2 months postoperatively, leaving 19 long-term survivors who were followed up for 26.2 ± 15.6 months. In the 11 patients who underwent postoperative cardiac catheterization, the mean diastolic gradient was 6.1 ± 2.7 mm Hg and the mean valve index 1.79 ± 0.76 cm²/m². Severe subaortic obstruction, due to the prosthetic mitral valve, occurred in three of five patients less than 5 years old.Among four patients who underwent tricuspid valve replacement there were no operative deaths; complete heart block occurred in three. At postoperative catheterization in two patients, the mean diastolic gradient was 3 and 5 mm Hg, and the valve index 1.32 and 1.7 cm²/m², respectively. Three patients with I-transposition of the great arteries who underwent replacement of the systemic atrioventricular valve were followed up for 12 to 37 months. At postoperative catheterization the mean diastolic gradient was 0 to 4 mm Hg and the valve index ranged from 1.68 to 1.88 cm²/m². Both aortic and mitral valves were replaced in three children. One died at operation and one 6 months after operation. The survivor has complete heart block but is in New York Heart Association functional class I.Eight xenografts (6 mitral, 1 left atrioventricular valve in I-transposition of the great arteries and 1 aortic) failed, requiring replacement 22 to 68 months after implantation. All were calcified to varying degrees. Valve failure began presenting 22 months after implantation, and of 25 valves implanted for 20 months or longer, 8 have been replaced. These 8 patients were younger (10.3 ± 0.2 years) at initial valve replacement than the other 17 patients (15.0 ± 0.3 years) followed up for 20 months or longer (p <0.05). High levels of γ-carboxyglutamic acid (GLA), a calciumbinding amino acid, were found in all six calcified xenografts analyzed, whereas none was found in a fresh porcine aortic valve or in an unimplanted xenograft. GLA-containing protein, laid down after implantation, may play a role in xenograft calcification.     

Doppler echocardiography in the evaluation of tricuspid stenosis

Seventeen patients (12 with native and five with prosthetictricuspid valves) with tricuspid stenosis were studied by Dopplerechocardiography followed by cardiac catheterization within24 h. The mean tricuspid diastolic pressure gradient was calculatedusing the modified Bernoulli equation. Tricuspid valve area(TVA) was calculated by the pressure half-time method (TVA =190 divided by pressure half-time). Data from Doppler echocardiographyand cardiac catheterization were compared. The Doppler-derivedtricuspid mean diastolic gradient was 1.9–9.9 mmHg (average5.3±2.5 mmHg), which correlated moderately well withthe catheterization-determined mean diastolic gradient of 2–17mmHg(average 7.3 ±4.0 mmHg), R = 0.74, standard error ofthe estimate (SEE) 1.70 mmHg, Y=0.45 x+2.00,P<0.001. TheDoppler-derived TVA was 0.56–1.58 cm² (average 1.06±0.32cm²), which correlated well with the catheterization-determinedTVA of 0.4–2.2cm² (average 1.06±0.46 cm²), R=0.81,SEE=0.20cm², Y=0.56 x+0.46, P<0.001. Of 12 patients undergoingright ventricular angiography, the angiographic and Dopplergrades of tricuspid regurgitation matched exactly in six anddiffered by one grade in the remaining six. This study demonstratedthat Doppler echocardiography compares very well to cardiaccatheterization in the quantification of tricuspid stenosisand in the assessment of concomitant tricuspid regurgitation.     

Accuracy of aortic stenosis severity assessment by Doppler echocardiography: importance of image quality

The aim of the present study was to investigate which factors could influence the accuracy of aortic stenosis severity assessment by Doppler echocardiography in an unselected population. Doppler echocardiographic determination of mean transvalvular pressure gradient and aortic valve area by continuity equation was performed in 101 patients before catheterization. According to the catheterization data, aortic stenosis was classified into 2 categories: mild to moderate (orifice area [Gorlin formula] > 0.75 cm², mean transvalvular gradient < 50 mmHg) and severe (orifice area < 0.75 cm², mean transvalvular gradient 50 mmHg). The influence of eight factors on the absolute difference in aortic valve area and mean transvalvular pressure gradient and on the concordant classification in the same category by both methods was investigated.Results. By multivariate analysis, the absolute difference in aortic valve area by both methods was significantly associated with poor image quality, absolute difference between mean catheterization and Doppler transvalvular gradient and inversely related to body mass index. Absolute difference in mean transvalvular gradients by both methods was significantly associated only with image quality. Poor image quality emerged as the only significant factor influencing the concordant classification between invasive and noninvasive studies according to orifice area (but not according to transvalvular pressure gradient).Conclusion. Echographic image quality significantly influences the accuracy of Doppler echocardiographic determination of aortic valve area and, to a lesser extent, of transvalvular pressure gradient. Therefore, the mere noninvasive approach is not suitable to every consecutive patient with aortic stenosis. Qualifications concerning overall image quality should identify patients most likely to benefit from catheterization.     

Hemodynamic assessment of the lonescu-shiley pericardial xenograft in the mitral position

While the very low thrombogenicity without anticoagulant therapy and generally good durability of the lonescu-Shiley bioprosthesis has been demonstrated, further hemodynamic assessment is necessary. The present study assessed cardiac function and heterograft performance during right and left heart catheterization at rest and exercise (three to six months postoperation) of eight patients with severe mitral stenosis and/or regurgitation prior to surgery. We found, comparing pre- and postoperative resting values, that mean pulmonary artery pressure decreased (32 ± 2.7 to 22 ± 3.5 mm Hg; P < 0.02), cardiac index increased (2.1 ± 0.09 to 2.5 ± 0.13 liters/min/m²; P < 0.01), pulmonary wedge pressure decreased (21 ± 2.3 to 13 ± 1.8 mm Hg; P < 0.01), and the clinical status (NYHA) improved markedly. Mean diastolic gradient across the pericardial xenograft was 6.1 ± 1.1 mm Hg at rest and 14.6 ± 2.3 mm Hg on exercise. The calculated xenograft surface area was 1.7 cm² at rest and 2.0 cm² during exercise. No regurgitation was detected in seven of eight patients. Thus, mitral lonescu-Shiley bioprosthesis provide excellent heterograft function.     

Percutaneous balloon valvuloplasty in mirror-image dextrocardia and rheumatic mitral stenosis

A 28-year-old woman with mirror-image dextrocardia and severe rheumatic mitral stenosis underwent successful percutaneous balloon mitral valvuloplasty (PBMV). Standard technique was altered to include transseptal catheterization via the left femoral vein and inter-atrial septal puncture with the transseptal needle rotated to a 7 o'clock position. The predilatation transmitral gradient (mean) of 16 mmHg decreased to 5 mmHg following PBMV. The valve area improved from 1.0 cm² to 2.6 cm². There were no complications. This case illustrates that transseptal catheterization can be accomplished safely in patients with unusual cardiac anatomy and mitral valvuloplasty can be performed in patients with mirror-image dextrocardia and rheumatic mitral stenosis. © 1993 Wiiey-Liss, Inc.     

A Doppler echocardiographic method for calculating volume flow across the tricuspid valve: correlative laboratory and clinical studies

In this study we tested a two-dimensional Doppler echocardiographic method for measuring volume flow across the tricuspid valve. Five anesthetized, open-chest dogs had a calibrated electromagnetic flow probe placed on the ascending aorta. Volume flow across the tricuspid valve was controlled by creating a variable femoral-to-pulmonary arterial shunt. Since no standard plane provided a direct view of the tricuspid valve orifice, tricuspid flow area was estimated by calculating a fixed circular flow orifice from the maximal late diastolic diameter of the tricuspid anulus in a four-chamber view. Doppler-determined velocities across the tricuspid valve and tricuspid anulus images in the four-chamber view were obtained in inspiration and expiration. For 24 cardiac outputs (0.6 to 4.0 liters/min), inspiratory tricuspid flow determined by the Doppler method correlated minimally better (r = .90, SEE = 0.30 liter/min) than did expiratory measurements (r = .89, SEE = 0.35 liter/min) with the time-averaged systemic flow determined electromagnetically. Doppler-determined tricuspid volume flows in four-chamber and short-axis two-dimensional echocardiographic views from 10 children were then compared with values determined simultaneously by thermodilution during cardiac catheterization. In the children, Doppler-determined flows in short-axis and four-chamber views, both in inspiration and expiration, were similar; when results for the two views were averaged in inspiration and expiration, the tricuspid flows predicted by the Doppler method were highly correlated (r = .98, SEE = 0.48 liter/min) with the results of thermodilution. The two-dimensional Doppler echocardiographic method provides a means of estimating volume flow across the tricuspid valve noninvasively.     

Echodoppler evaluation of the normally functioning Saint-Jude's aortic valve prosthesis

The aims of this study were: to define Doppler echocardiographic criteria of normality of aortic St Jude Medical (SJM) valve prostheses with respect to their size and to verify the validity of the continuity equation in the determination of prosthetic valve functional surface area. Forty patients with apparently normally functioning SJM prostheses without other cardiac disease were investigated at least one month after surgery. The group consisted in 1 n. 19, 6 n. 21, 9 n. 23, 12 n. 25 and 12 n. 27 SJM prostheses. The following parameters were measured: the maximum transprosthetic velocity, maximum and mean transprosthetic pressure gradients, permeability index and the Doppler surface area calculated by the continuity equation using the method proposed by Skjaerpe. The global results were as follows: maximum velocity = 2.5 +/- 0.4 m/s (1.8-3.7 m/s); maximum gradient = 26.9 +/- 9.8 mmHg (14-53 mmHg); mean gradient = 13.7 +/- 5.6 mmHg (7-30 mmHg); permeability index = 0.41 +/- 0.09 (0.23-0.57); Doppler surface area = 1.89 +/- 0.66 cm2 (0.73-3.23 cm2). When the prostheses were considered according to their sizes a weak negative correlation was observed between the mean pressure gradients and the size of the prostheses: r = -0.43, p less than 0.05 and a positive correlation between Doppler surface area and the theoretical prosthetic surface area: r = 0.71, p less than 0.005; SD = 0.45 cm2. No significant differences were observed between the pressure gradients and velocities of each size of prosthesis except when sizes 21 + 23 were compared with the large sizes (n. 25 + 27).(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of morphine and aminophylline on the severity of obstruction to left ventricular outflow in idiopathic hypertrophic subaortic stenosis: potential adverse effects in treatment of pulmonary edema

Although morphine sulfate and aminophylline are commonly employed in the management of acute pulmonary edema of diverse etiologies including idiopathic hypertrophic subaortic stenosis (IHSS), the effects of morphine and aminophylline on left ventricular (LV) outflow obstruction in IHSS are unknown. Thus to determine the actions of morphine and aminophylline in IHSS, seven patients with IHSS (mean peak resting systolic gradient 16 mmHg, mean Valsalva provoked gradient 87 mmHg) received 5 mg morphine intravenously and simultaneous LV and brachial arterial pressures were continously monitored and cardiac outputs obtained. On return to control hemodynamics, 250 mg aminophylline was infused in three patients and hemodynamics repeated. Peak increase in gradient with morphine occurred in 5 min in each patient and average maximal gradient was 48 mmHg (p<0.001). Peak LV systolic pressure increased 158 to 182 mmHg (p<0.05); LV end-diastolic pressure declined 12 to 8 mmHg (p<0.005); cardiac index decreased 3.18 to 2.89 l/min/m² (p<0.005); while heart rate and total systemic vascular resistance were unchanged (p>0.05). Aminophylline increased peak gradient to 57 mmHg; lowered LV end-diastolic pressure by 2 mmHg; decreased total systemic vascular resistance 1610 to 1120 dyne s · cm^?5; while cardiac index was unchanged. Therefore morphine and aminophylline can rapidly increase LV outflow obstruction to marked extents in IHSS. These data indicate morphine worsens subaortic stenosis by decrease in LV preload through systemic venodilation, whereas aminophylline increases intraventricular gradient predominantly by peripheral arterial dilation. Thus morphine and aminophylline should be avoided, or used cautiously in low doses, in management of acute pulmonary edema in IHSS.     

A prospective study comparing the haemodynamic with the cross-sectional echocardiographic diagnosis of rheumatic tricuspid stenosis

The value of cross-sectional echocardiography in the diagnosisof tricuspid valve stenosis is not clearly established. We prospectivelystudied by cardiac catheterization 42 consecutive patients,with a mean age of 29 ± 11 years, who exhibited the cross-sectionalechocardiographic features of tricuspid valve stenosis, definedas: diastolic doming of all three tricuspid leaflets and leafletthickening with restrictive motion. To expose occult and amplifyborderline tricuspid diastolic gradients, simultaneous rightatrial and right ventricular pressures were recorded in thebasal state, after incremental infusions of normal saline to200,400,500, 700 or 1000 ml until a mean right atrial pressureof 12 mmHg was achieved, and finally after intravenous administrationof 0.6 mg of atropine. Eighteen patients, Group 1, (43%) exhibitedmean tricuspid diastolic gradients >2mmHg after saline infusion,increasing from a mean of4 ± 2 to 9 ± 3 mmHg,(P <0.001), 14 (33%) having gradients <2mmHg in the basalstate, together with four (10%) increasing from 1.7 ±0.2 to 4.5 ± l.2 mmHg (P <0.01) after provocationwith fluid challenge. In the remaining 24 patients, Group 2,(57%) the mean tricuspid diastolic gradient was <2 mmHg,both at rest and after provocative manoeuvres. We conclude thatthe cross-sectional echocardiographic features of tricuspidvalve stenosis are not a precise indicator of tricuspid valvestenosis. Provocative manoeuvres during haemodynamic studiesare required to expose occult or amplify borderline tricuspiddiastolic gradients in a minority of patients with the cross-sectionalechocardiographic features of tricuspid stenosis.     

Prosthesis-Patient Mismatch Following Transcatheter Aortic Valve Replacement With Supra-Annular and Intra-Annular Prostheses

ObjectivesThis study sought to compare the frequency of prosthesis-patient mismatch (PPM) with self-expandable valves (SEV) to balloon-expandable valves (BEV).BackgroundPPM has been associated with increased mortality after transcatheter aortic valve replacement. Data on the frequency of PPM as a function of supra-annular or intra-annular position of transcatheter heart valves are insufficient.MethodsA total of 757 patients treated with SEV (CoreValve, Evolut R) and BEV (SAPIEN THV/XT/3) were enrolled in the present analysis between August 2007 and June 2017. PPM was classified based on discharge prosthetic effective orifice area indexed to body surface area (BSA) as severe (<0.65 cm²/m²) or moderate (0.65 to 0.85 cm²/m²) in the general population, and as severe (<0.60 cm²/m²) or moderate (0.60 to 0.90 cm²/m²) in the obese population (body mass index ≥30 kg/m²).ResultsPropensity score matching resulted in 224 matched pairs. At discharge, SEV were associated with a lower incidence of PPM compared with BEV (PPM, 33.5% vs. 46.9%; p = 0.004; severe PPM, 6.7% vs. 15.6%; p = 0.003). The lower frequency of severe PPM in SEV was observed even in patients with larger annulus. Although patients with BSA >1.83 m² had a significantly lower incidence of PPM with SEV compared with BEV, there was no significant difference in patients with BSA ≤1.83 m². We found no impact of PPM on cardiovascular mortality or New York Heart Association functional class at 1 year.ConclusionsSEV were associated with a lower frequency of PPM compared with BEV irrespective of annulus area. The difference was mainly driven by larger patients with BSA >1.83 m².     

The influence of prosthesis size and design on exercise dynamics after aortic valve replacement

BACKGROUND AND AIM OF THE STUDY: Residual gradient following aortic valve replacement (AVR) may adversely affect clinical outcome. The size and design of the valve may influence these characteristics. The study aim was to determine the influence of prosthesis physical size and leaflet design on hemodynamic performance after mechanical AVR. METHODS: After AVR, two patient groups with a range of valve sizes were studied. Group 1 patients (n=19) each received a monoleaflet valve; group 2 patients (n=18) each received a bileaflet valve. Transthoracic echocardiography was performed at rest and after graded bicycle ergometry to assess prosthetic valve parameters, including mean and peak transvalvular gradient and effective orifice area (EOA). RESULTS: Transprosthetic gradients (mean and peak) measured at rest, maximum exercise and 3-min recovery were related to indexed geometric orifice area (IGOA) by an exponential decay function, with no significant advantage for either valve design. However, in valve sizes < or =25 mm the bileaflet valves demonstrated lower gradients, both at rest and under exercise conditions (mean gradient during exercise, bileaflet versus monoleaflet 19.9 +/- 7.2 mmHg versus 25.6 +/- 6.3 mmHg, p = 0.01). Similarly, EOAs were larger in the bileaflet group when equivalent GOAs < or =2.5 cm2 were compared (EOA: bileaflet versus monoleaflet 1.51 +/- 0.33 cm2 versus 1.14 +/- 0.26 cm2, p = 0.018). The total work performed correlated with prosthesis diameter (r2 = 0.81, p = 0.037) and was not influenced by valve design. CONCLUSION: The hemodynamic performance of mechanical aortic valves, including transprosthetic gradient and maximum exercise work performed, related principally to the prosthesis physical size. However, within the smaller valve sizes, the bileaflet design appeared to offer hemodynamic advantages.     

Method for computation of cardiac output in mitral stenosis independent of left ventricular dimensions and kinetic state: correlation with cardiac catheterization via the Fick method

An hydraulic orifice formula offering the possibility of quantifying cardiac output in conditions of mitral stenosis is tested using potentially noninvasive portions of catheterization data from patients evaluated for obstructive mitral valve disease. The equation studied is V = (1/21) R A T2, where V is the cardiac output (ml/min), R is the heart frequency, A is the mitral valve area (cm2), and T is the diastolic filling interval (sec/min). The mitral valve area was determined by the Gorlin formula, and R and T were measured from the pressure tracings recorded at cardiac catheterization. The degree of correspondence between the equation tested and the measured cardiac output as determined by the Fick principle technique is characterized by r = 0.87, SE = 450 ml/min, N = 10. The results suggest that the new formulation may offer a noninvasive method for estimating the cardiac output status of patients with mitral valve disease once mitral valve area is measured either at catheterization or by two-dimensional echocardiography.     

Doppler evaluation of the Sorin and Medtronic-Hall prostheses in the aortic position

Doppler characteristics of normally functioning tilting disk prostheses in aortic position were studied in 55 patients (30 Medtronic-Hall and 25 Sorin) whose valvular function was considered normal using clinical and echocardiographic evaluation. Peak gradients, mean gradients and effective orifice area were estimated for different sizes of prostheses. The peak gradient calculated from maximal aortic velocity was 27.3 +/- 11.1 mmHg in Sorin and 21.1 +/- 9.7 mmHg in Medtronic-Hall valves; the mean gradients were 12.9 +/- 6.2 mmHg and 10.8 +/- 5.7 mmHg in Sorin and Medtronic-Hall valves respectively. The effective orifice area calculated by the continuity equation was 1.4 +/- 0.5 cm2 in Sorin and 1.5 +/- 0.57 cm2 in Medtronic-Hall prostheses; the performance index calculated as the ratio between functional area and manufactured area was 0.4-0.6 for Medtronic-Hall and 0.45-0.52 for Sorin prostheses. Prosthetic regurgitation was found in 64% of Sorin valves and 80% of Medtronic-Hall valves; prosthetic regurgitation was mild in 81% and moderate in 19% of cases. Doppler echocardiography is a reliable method for the characterization of the normal function of prosthetic aortic valves and provides information similar to cardiac catheterization.     

Percutaneous balloon valvuloplasty for bioprosthetic mitral valve stenosis

Percutaneous transcatheter mitral valvuloplasty is the indicated treatment of choice for symptomatic native mitral valve stenosis, but there have been limited reports of successful procedures of balloon valvuloplasty for bioprosthetic mitral valve stenosis. We present the case of a 62-year-old woman suffering from progressive dyspnea due to bioprosthetic mitral valve stenosis. The measured mean pressure gradient across the mitral valve was 30 mmHg and the mitral valve area was 0.73 cm². Redoing mitral replacement was considered high risk and was refused by the patient. Percutaneous balloon valvuloplasty was performed with an Inoue balloon catheter inflated to 20 mm. The patient’s symptoms immediately improved after the procedure, with no procedure-related complications. The mean pressure gradient across the valve decreased to 19 mmHg, and the mitral valve area increased to 1.21 cm² in postprocedural echocardiography. We conducted a literature search and identified 26 cases of balloon valvuloplasty for degenerated bioprosthetic valves. Of these, 14 cases were bioprosthetic mitral valves, and the results were favorable. However, more case reports are required to establish an evidence base for future expert recommendation of balloon valvuloplasty of prosthetic mitral valve. Meanwhile, balloon valvuloplasty will serve a niche role in highly selected patients with prosthetic mitral valve stenosis.     

Clinical and hemodynamic prognosis after tricuspid valve replacement with bioprosthesis]

Between 1974 and 1990, 58 patients underwent tricuspid valve replacement with a porcine bioprosthesis (Hancock 42, Carpentier-Edwards 16) in the course of polyvalvular replacement (double 21, triple 37). Early postoperative mortality was 12%: 16 patients died secondarily, usually of cardiac causes. The actuarial survival (1 patient lost to follow-up) was 81 +/- 11% at 5 years and 60 +/- 17% at 10 years. Two patients were reoperated for dysfunction of a Hancock bioprosthesis, 11 and 15 years after implantation. At long-term, with an average follow-up of 108 +/- 48 months, 82% of survivors (28/34) were clinically improved. Doppler echocardiography was performed in 29 patients in February 1991. In 21 cases, with a follow-up of 88 +/- 40 months, the bioprosthesis was normal with an average diastolic transprosthetic pressure gradient of 3.8 +/- 1.7 mmHg. In 7 patients followed up for 129 +/- 40 months (p < 0.05) moderate dysfunction of the Hancock prosthesis was observed with a mean diastolic pressure. Severe dysfunction of a Hancock prosthesis was observed in 1 case. Fixed pulmonary hypertension was noted in 11 cases and was associated with a poor clinical result and a raised mean diastolic transprosthetic pressure gradient. The durability and haemodynamic performance of tricuspid porcine bioprostheses are satisfactory in the long term. Prosthetic dysfunction is correlated to the duration of implantation of the bioprosthesis and to persistent pulmonary hypertension.     

Effect of catheter positioning on the variability of measured gradient in aortic stenosis

The purpose of this study was to quantify the variation in measured aortic valve gradient and calculated aortic valve area when different techniques of cardiac catheterization were utilized. Hemodynamic assessment of aortic stenosis severity requires an accurately determined pressure gradient. In aortic stenosis, the presence of intraventricular pressure gradients and downstream pressure recovery within the aorta means that a range of aortic valve gradients could be measured in a given patient depending upon catheter position and measurement technique. To quantify the degree of variation in measured gradient and calculated aortic valve area, we generated transvalvular gradients by nine different techniques in 15 patients (11 men, 4 women; 29-86 years old). Patients were divided into those with severe aortic stenosis (aortic valve area ≤ 0.6 cm², n = 6) and those with moderately severe aortic stenosis (aortic valve area 0.61-0.90 cm², n = 9). Considerable variation in measured gradient and calculated aortic valve area was observed. The maximum variation in gradient was similar in severe and moderately severe aortic stenosis groups (33 mm Hg. vs. 32 mm Hg., p = NS). However, the variation in gradient as a percent of maximum gradient was greater (P < 0.05) in the moderately severe aortic stenosis group. The maximum variation in calculated aortic valve area was 0.1 cm² in the severe group and 0.3 cm² in the moderately severe group (P < 0.01). An intraventricular gradient, present in 13 of 15 (87%) patients, was partially responsible for the variation in pressure gradient measurement and calculated aortic valve area. We conclude that in patients with valvular aortic stenosis, catheterization technique has an important impact on the hemodynamic assessment of aortic stenosis severity. This is particularly true in patients with moderately severe aortic stenosis where any variation tends to represent a larger percentage of the total gradient. © 1993 Wlley-Liss, Inc     

Effect of Transcatheter Aortic Valve Replacement on Right Ventricular–Pulmonary Artery Coupling

ObjectivesThe aim of this study was to test the hypothesis that the acute left ventricular (LV) unloading effect of transcatheter aortic valve replacement (TAVR) would improve right ventricular (RV) function and RV–pulmonary artery (PA) coupling in patients with severe aortic stenosis (AS).BackgroundRV dysfunction is an ominous prognostic marker in patients undergoing TAVR, suggesting that relief of obstruction might be less beneficial in this cohort. However, the left ventricle and right ventricle influence each other through ventricular interaction, which could lead to improved RV function through LV unloading.MethodsProspective invasive hemodynamic measurements with simultaneous echocardiography were performed in symptomatic patients with severe AS before and immediately after TAVR.ResultsForty-four patients (mean age 81 ± 8 years, 27% women) with severe AS underwent TAVR. At baseline, right atrial, PA mean (27 ± 7 mm Hg), and pulmonary capillary wedge (16 ± 4 mm Hg) pressures were mildly elevated, with a low normal cardiac index (2.3 l/min/m²). Pulmonary vascular resistance was mildly elevated (222 ± 133 dynes · s/cm⁵) and PA compliance mildly reduced (3.4 ± 01.4 ml/mm Hg). Following TAVR, aortic valve area increased (from 0.8 ± 0.3 to 2.7 ± 1.1 cm²; p < 0.001) with a reduction in mean aortic gradient (from 37 ± 11 to 7 ± 4 mm Hg; p < 0.001) and an increase in cardiac index (from 2.3 ± 0.5 to 2.5 ± 0.6 l/min/m²; p = 0.03). LV stroke work, end-systolic wall stress, and systolic ejection period decreased by 23% to 27% (p < 0.001 for all), indicating substantial LV unloading. RV stroke work (from 16 ± 7 to 18 ± 7 mm Hg · ml; p = 0.04) and tricuspid annular systolic velocities (from 9.5 ± 2.0 to 10.4 ± 3.5 cm/s; p = 0.01) increased, along with a decrease in PVR (194 ± 113 dynes · s/cm⁵; p = 0.03), indicating improvement in RV-PA coupling. Increased RV stroke work following TAVR directly correlated with the magnitude of increase in aortic valve area (r = 0.58; p < 0.001).ConclusionsAcute relief in obstruction to LV ejection with TAVR is associated with improvements in RV function and RV-PA coupling. These findings provide new insights into the potential benefits of LV unloading with TAVR on RV dysfunction in patients with severe AS.     

Repeat balloon aortic valvuloplasty

This paper attempts to determine limitations and indications of performing a second balloon aortic valvuloplasty procedure (BAV2) because of restenosis, which is the major limitation of this technique. From September 1985 to December 1989, 357 patients underwent a primary BAV (BAV1) and 67 patients had a BAV2. Forty-two patients (group A) had repeat catheterization because they were markedly symptomatic 11 ± 7 months after BAV1. Twenty-five patients (group B) came from a group of 73 patients who had been systematically scheduled for repeat catheterization in order to evaluate the hemodynamic restenosis rate 8 ± 3 months after BAV. At time of BAV2 most of the patients of group A were severely disabled. Comparison of pre-BAV2 gradient and aortic valve area with pre-BAV1 measurements showed in a slightly less severe degree of aortic stenosis in group A and in group B with any difference in cardiac index and ejection fraction. Immediately following BAV2, the gradient decreased from 72 ± 22 to 33 ± 15 mm Hg (P ± and aortic valve area increased from 0.56 ± 0.18 to 0.85 ± 0.28 cm ²) (p < 0.001) in group A. In group B, gradient decreased from 68 ± 15 to 33 ± 15 mm Hg (p < 0.001) and aortic valve area increased from 0.70 ± 0.16 to 0.90 ± 0.25 cm² (p < 0.001). Comparison of the post-BAV2 peak systolic gradient, aortic valve area, ejection fraction, and cardiac index with post-BAV1 measurements revealed no significant differences in the two groups, but the absolute increase in aortic valve area obtained at BAV2 was significantly less than at BAV1 in group B (0.20 ± 0.22 vs 0.31 ± 0.16 cm² p < 0.02). The larger balloon size used for BAV2 than for BAV1 did not increase the final valve area at BAV2. In-hospital mortality was 3%. The use of a better profiled catheter with an arterial introducer explained the lower rate of vascular complications (4%). This report demonstrates that when BAV is indicated a second procedure can be performed safely and with low risk in symptomatic patients. © 1992 Wiley-Liss, Inc.     

Doppler Echocardiographic Assessment of the Bjork-Shiley Monostrut Valve Prosthesis in the Aortic Position

In order to determine the standard Doppler hemodynamic characteristics of the Bjork-Shiley monostrut aortic prosthesis and the value of the continuity equation to calculate the prosthetic valvular area, we performed Doppler echocardiographic study in 106 stable patients with this prosthesis and in 7 patients with suspicion of aortic Bjork-Shiley dysfunction. We measured maximum and mean Doppler gradients, prosthetic valvular area using the continuity equation, and degree of aortic regurgitation. The maximum and mean Doppler gradients in the 106 stable patients ranged from 9.5 to 51 mmHg (X?= 28.9 ± 11 mmHg) and from 2 to 24 mmHg (X?= 12.7 ± 5.2 mmHg), respectively. Maximum Doppler gradients > 45 mmHg and mean Doppler gradients > 20 mmHg occurred only in size 23 or smaller. No patient had a mean Doppler gradient > 25 mmHg. We found significant differences between sizes 25 and 27 (P < 0.01) and 21 and 25 (P < 0.01), but not between sizes 19, 21, and 23, or 23 and 25. There was significant difference in Doppler prosthetic valvular area between each valve size. The correlation coefficient between the prosthetic size and the echo-Doppler valvular area was 0.89 according to a lineal equation (SEE = 16). We could demonstrate mild aortic regurgitation in 25 cases (24%). The Doppler-derived prosthetic valvular area was < 0.38 cm² in two patients with obstruction and > 2 cm² in three patients with regurgitation alone. We conclude that high pressure gradients can be observed through the smallest sizes of the Bjork-Shiley monostrut aortic prostheses. Mild aortic regurgitation is a common finding. Our values are suggested as a reference for comparison in the case of suspected Bjork-Shiley valve dysfunction. The Doppler-derived prosthetic valvular area may be useful in patients with dysfunction of this prosthesis, especially to differentiate obstruction and regurgitation from regurgitation alone.     

Late (5 to 132 months) clinical and hemodynamic results after either tricuspid valve replacement or anuloplasty for ebstein's anomaly of the tricuspid valve

Late clinical and hemodynamic observations are described in 6 patients who had either tricuspid valve anuloplasty (TVA) (2 patients) or tricuspid valve replacement (TVR) (4 patients) 5 to 132 months earlier for Ebstein's anomaly of the tricuspid valve unassociated with right ventricular outflow obstruction. Of the 6 patients, 4 had improved postoperatively by 1 New York Heart Association functional class and 2 had improved by 2 functional classes. The cardiothoracic ratio decreased 5 to 12 months after either TVR or TVA in all 6 patients (from a mean of 0.72 to 0.62). Repeat cardiac catheterization 5 to 12 months after TVA or TVR disclosed that the right atrial mean pressure had increased from a median of 4.0 to 10.5 mm Hg (p = 0.05); the right ventricular peak systolic pressure had increased from 19.0 to 31.5 mm Hg (p = 0.02); the right ventricular end-diastolic pressure had increased from 5.0 to 9.0 mm Hg (p = 0.05); the systemic arterial peak systolic pressure had increased from 115 to 123 mm Hg (p = 0.03); and the cardiac index had increased (in all 4 patients in whom both pre- and postoperative values were available) from 1.7 to 2.9 liters/min/m² (p = 0.06). Thus, the tricuspid valve operations in our 6 patients with Ebstein's anomaly were associated with a decrease in symptoms of cardiac dysfunction, a decrease in cardiac size, an increase in cardiac index and an increase in right ventricular and right atrial pressures. The elevation of the right atrial pressures postoperatively may have resulted from increased right ventricular filling pressures, persistent tricuspid regurgitation or bioprosthetic stenosis.