Left ventricular remodeling after aortic valve replacement]

The aim of the study was the assessment of left ventricular (LV) systolic function and left ventricular mass following aortic valve replacement (AVR) due to aortic valve stenosis as well as the influence of regression of LV hypertrophy in patients with normal and impaired LV systolic function prior to surgery. 74 patients with severe aortic valve stenosis (29 female, 45 male, mean age 66 +/- 18 years) were divided into 2 groups according to LV ejection fraction (EF): Group 1 with EF > 50% (n = 40); Group 2 with EF < or = 50% (n = 34). Furthermore, patients were differentiated into a group A without (n = 53) and a group B with aortic regurgitation (< or = II degrees, n = 21). All patients were examined by transthoracic echocardiography before and 1 month after surgery. There was a significant decrease of LV enddiastolic and endsystolic volume indices following AVR in group 2 and group B. Patients with preoperatively lower EF (group 2) showed an increase in LV ejection fraction from 39 +/- 10% before AVR to 47 +/- 11% after AVR (p < 0.001), whereas patients with preoperative normal EF (group 1) showed a significant decrease in EF (from 62 +/- 8% to 57 +/- 10%, p < 0.05). Also patients with combined aortic valve disease before AVR had an increase of EF after surgery (from 45 +/- 14% to 56 +/- 14%, p < 0.03). There were significant decreases of interventricular septum thickness and LV posterior wall thickness in group 1 and group A, whereas a significant decrease of LV enddiastolic diameter index was noted only in group B. Improvement of the NYHA functional class could be demonstrated in group 2 from 2.8 +/- 0.7 before to 2.2 +/- 0.6 after AVR, as well as in group B from 2.9 +/- 0.7 before to 1.9 +/- 0.7 after surgery. In conclusion, patients with impaired LV function or combined aortic valve disease showed a significant improvement of left ventricular systolic function after AVR, while patients with normal LV function presented a slight decrease of EF. There was a significant regression of left ventricular muscle mass in all groups independent of the left ventricular functional status.     

Left ventricular hypertrophy and remodeling after aortic valve replacement

Left ventricular geometric remodeling and regression of hypertrophy were assessed after aortic valve replacement with a mechanical prosthesis in 37 patients with aortic stenosis and 39 with aortic insufficiency, aged 54.2 +/- 14.3 and 52.6 +/- 16.6 years, respectively. The follow-up period was 2 years. In patients with aortic insufficiency, ejection fraction increased from 54.4 +/- 3.5 preoperatively to 59.6 +/- 3.4 after 6 months and 61.7 +/- 2.7 after 2 years. In patients with aortic stenosis, ejection fraction increased from 56.6 +/- 5.1 preoperatively to 63.9 +/- 4.4 after 6 months and 71.7 +/- 4.1 after 2 years. Geometric remodeling, regression of hypertrophy, and increased ejection fraction of the left ventricle were similar in both groups at 6 months after surgery, but after 2 years of follow-up, greater improvement was found in patients who had undergone valve replacement for aortic stenosis.     

Left ventricular function after aortic valve replacement.

Changes in haemodynamics and in systolic time intervals, early after valve replacement, were studied in a group of 15 patients. Though all the haemodynamic measurements were within normal limits at 44 hours after operation, there was a persistent change in systolic time intervals (shortening of left ventricular ejection time and electromechanical systole, and prolongation of pre-ejection period and increase in the ratio PEP/LVET). The effect of periods of myocardial ischaemia during cardiopulmonary bypass on myocardial function is suggested as the explanation for the changes observed.     

Left ventricular function after aortic valve replacement.

Changes in haemodynamics and in systolic time intervals, early after valve replacement, were studied in a group of 15 patients. Though all the haemodynamic measurements were within normal limits at 44 hours after operation, there was a persistent change in systolic time intervals (shortening of left ventricular ejection time and electromechanical systole, and prolongation of pre-ejection period and increase in the ratio PEP/LVET). The effect of periods of myocardial ischaemia during cardiopulmonary bypass on myocardial function is suggested as the explanation for the changes observed.     

Left ventricular function at rest and during exercise after aortic valve replacement in patients with aortic regurgitation

To determine the effect of aortic valve replacement on reversing abnormalities of left ventricular function in patients with aortic regurgitation, radionuclide cineangiography was used to study 16 symptomatic patients with aortic regurgitation before and 6 months after aortic valve replacement. Before operation, left ventricular ejection fraction was 46 ± 3 percent at rest (normal mean ± standard error of the mean 57 ± 1 percent; P < 0.001), and decreased to 37 ± 4 percent during exercise (normal 71 ± 2 percent; P < 0.001). After operation, ejection fraction rose to 58 ± 4 percent at rest, indistinguishable from the normal value, and during exercise was 53 ± 4 percent, increased (P < 0.001) from before operation but significantly (P < 0.001) subnormal. Thus, aortic valve replacement can improve but usually does not normalize left ventricular function during exercise in symptomatic patients with aortic regurgitation.     

Left ventricular remodeling early after aortic valve replacement: differential effects on diastolic function in aortic valve stenosis and aortic regurgitation

OBJECTIVES: The aim of this study was to evaluate the effect of aortic valve replacement (AVR) on left ventricular (LV) function and LV remodeling, comparing patients with aortic valve stenosis to patients with aortic regurgitation. BACKGROUND: Aortic valve disease is associated with eccentric or concentric LV hypertrophy and changes in LV function. The relationship between LV geometry and LV function and the effect of LV remodeling after AVR on diastolic filling, in patients with aortic valve stenosis compared with aortic regurgitation, are largely unknown.Nineteen patients with aortic valve disease (12 aortic valve stenosis, 7 aortic regurgitation) were studied using magnetic resonance imaging to assess LV geometry and LV function before and 9 +/- 3 months after AVR. Ten age-matched healthy males served as control subjects. RESULTS: Before AVR, the ratio between left ventricular mass index (LVMI) and left ventricular end-diastolic volume index (LVEDVI) was only increased in patients with aortic valve stenosis (1.37 +/- 0.16 g/ml) compared with control subjects (0.93 +/- 0.08 g/ml, p < 0.05). After AVR, LVMI/LVEDVI decreased significantly in aortic valve stenosis (to 1.15 +/- 0.14 g/ml, p < 0.0001), but increased significantly in aortic regurgitation (1.02 +/- 0.20 g/ml to 1.44 +/- 0.27 g/ml, p < 0.0001). Before AVR, diastolic filling was impaired in both aortic valve stenosis and aortic regurgitation. Early after AVR, diastolic filling improved in patients with aortic valve stenosis, whereas patients with aortic regurgitation showed a deterioration in diastolic filling. CONCLUSIONS: Early after AVR, patients with aortic valve stenosis show a decrease in both LVMI and LVMI/LVEDVI and an improvement in diastolic filling, whereas in patients with aortic regurgitation, LVMI decreases less rapidly than LVEDVI, causing concentric remodeling of the LV, most likely explaining the observed deterioration of diastolic filling in these patients.     

Left ventricular remodeling after pulmonary autograft replacement of the aortic valve (Ross operation)

BACKGROUND AND AIM OF THE STUDY: Aortic valve replacement (AVR) with a pulmonary autograft is an alternative treatment for young patients with aortic valve disease. Superior hemodynamic performance of the pulmonary autograft, and impact on parameters of left ventricular function were analyzed. METHODS: Thirty patients (21 males, nine females; mean age 29.97+/-12.29 years; range: 6-54 years) underwent a Ross procedure between November 1997 and November 1999. Seven patients (23%) were children (aged <15 years). In total, 22 patients were analyzed; each had at least three months follow up. Eleven patients had predominant aortic stenosis (AS), and 11 had aortic insufficiency (AI). RESULTS: There were no operative deaths. Two patients developed severe insufficiency, and the autograft was replaced with a mechanical valve. Pre- and postoperative echocardiograms were reviewed. The mean neoaortic maximal gradient was 7.85+/-5.59 mmHg (range: 3-29 mmHg). AS patients showed reduced interventricular septal (IVS) thickness at one month (from 13.27+/-3.69 to 11.60+/-2.44 mm; p = 0.0165) and 18 months after surgery (p = 0.0104). Left ventricular posterior wall (LVPW) thickness was reduced from 12.04+/-3.75 to 9.48+/-2.47 mm (p = 0.0338) at one month and 18 months (p= 0.0128) after surgery. The left ventricular end-diastolic internal dimension (LVIDd) decreased from 50.71+/-10.20 to 44.98+/-7.29 mm (p = 0.0491) at one month after surgery. In AI patients, LVPW and IVS thicknesses showed no significant variation, and LVIDd was decreased at one month (from 68.50+/-8.39 to 59.04+/-9.21 mm; p = 0.0017) and 18 months (p = 0.0229) after surgery. Left ventricular end-systolic internal dimension (LVIDs) decreased from 44.06+/-6.39 to 39.03+/-7.99 mm (p = 0.0081) at three months after surgery. Left ventricular mass index (LVMI) in the AS group decreased from 179.01+/-62.26 to 115.74+/-37.62 g/m2 (p = 0.0021) at one month after surgery, and at 18 months was normal, with a decrease from 208.77+/-32.89 to 95.89+/-28.82 g/m2 (p= 0.0003) (n = 5). In the AI group, LVMI decreased from 186.25+/-85.21 to 140.58+/-62.02 g/m2 (p = 0.0011) at one month after surgery, and at 18 months from 217.70+/-98.02 to 146.73+/-84.55 g/m2 (p= 0.0131) (n = 5). CONCLUSION: The pulmonary autograft procedure can be used safely to replace the aortic valve, and allows optimal hemodynamic performance, with no significant aortic regurgitation. The Ross procedure results in normalization of left ventricular dimensions and improvement of left ventricular function early in the postoperative period.     

Left ventricular mass regression after aortic valve replacement with CryoLife-O'Brien stentless aortic bioprosthesis

BACKGROUND AND AIM OF THE STUDY: Left ventricular (LV) hypertrophy has been shown adversely to affect LV function and late outcome after aortic valve replacement (AVR). The study aim was to assess the time course of LV mass regression (LVMR) after AVR with a CryoLife-O'Brien stentless bioprosthesis, and to identify factors affecting late reduction of myocardial hypertrophy. METHODS: In total, 113 patients (60 males, 73 females; mean age 70.9+/-6.5 years) were studied by echocardiography preoperatively, at discharge, at six and 12 months postoperatively, and yearly thereafter. LV diameter and thickness were measured using M-mode echocardiography; LV mass was calculated using the Devereux formula and indexed by body surface area (BSA). RESULTS: LV end-systolic diameter, end-diastolic diameter, septal thickness and wall thickness decreased significantly after surgery (p <0.001). LV mass index (LVMI) was reduced by 16.6, 13.6, 10.1, 3.1, 3.3, 1.7, 2.6, and 1.8% at discharge and at 6 months and 1, 2, 3, 4, 5, and 6 years, respectively. Most LVMR occurred within the first year, with further (not significant) reductions at later examinations. Male sex (p = 0.002), arterial blood pressure > or =150 mmHg (p <0.001), LV ejection fraction (LVEF) < or =35% (p = 0.01), NYHA functional class > or = III (p = 0.01), atrial fibrillation (p <0.001), mean transvalvular gradient > or =40 mmHg (p = 0.001), and prevalent aortic incompetence (p <0.001) were factors influencing LVMR, independently of baseline effective orifice area and prosthesis size. CONCLUSION: AVR with the CryoLife-O'Brien stentless prosthesis resulted in significant LVMR. These findings encourage the use of this bioprosthesis in appropriate patients.     

Left ventricular mass regression after aortic valve replacement with the mosaic bioprosthesis

BACKGROUND AND AIMS OF THE STUDY: The study aim was to evaluate the hemodynamic performance and extent of left ventricular (LV) mass regression after aortic valve replacement (AVR) with the Mosaic bioprosthesis within the first postoperative year. METHODS: Between 1994 and 1999, 366 patients (203 males, 163 females) underwent AVR with the Mosaic bioprosthesis at five centers in Europe. Mean age at implant was 71.1 years (range: 34.5-86.8 years). LV mass assessment and hemodynamic evaluation were performed using transthoracic echocardiography within six days postoperatively, after six months, and at annual intervals thereafter. RESULTS: LV mass index decreased significantly in patients with valve sizes 21 to 27 mm, from 184.4+/-56.2 g/m2 postoperatively to 157.3+/-45.5 g/m2 after one year (14.7% decrease). The 19-mm valve group did not show significant LV mass index reduction (from 210.4+/-39.4 to 195.0+/-59.4 g/m2; 7.3%). Patients with significant LV mass index regression had survival benefits after seven years. Mean pressure gradients after one year were 16.0+/-4.3, 14.2+/-5.4, 12.8+/-5.3, 11.1+/-4.0 and 10.5+/-3.7 mmHg for 19, 21, 23, 25 and 27 mm valves, respectively. CONCLUSION: Implantation of the Mosaic bioprosthesis resulted in a significant regression of LV mass for the valves sizes 21 to 27 mm, corresponding to very low pressure gradients for a stented bioprosthesis.     

Time course of left ventricular remodeling after stentless aortic valve replacement

BACKGROUND: Stentless aortic valves are associated with a significant decrease in left ventricular hypertrophy. This study examined the time course and factors affecting left ventricular mass regression (LVMR) after aortic valve replacement (AVR) with Cryolife O'Brien (CLOB) (Cryolife International, Atlanta, Ga) stentless valves. METHODS: Between 1993 and 2000, 130 consecutive patients underwent AVR with CLOB. Mean age was 71.3 +/- 6.3 years. Sixty-four (49.2%) were male. Mean body surface area (BSA) was 1.7 +/- 0.2 m(2). Mean valve size implanted was 23.6 +/- 2.0 mm. All patients were monitored with serial echocardiograms; the first study was performed preoperatively, and subsequent controls were at 6 months, 1, 2, 3, 4, 5, 6, and 7 years, respectively. Left ventricular mass was calculated by the Devereux formula and indexed by BSA. RESULTS: Analysis of variance showed a significant reduction in the left ventricular mass index (LVMI) over time (P < .001). Most LVMRs occurred within the first 6 months, and after 1 year LVMI had decreased by 37.5% with further, but not statistically significant, reductions at later examinations. We found that baseline BSA > 1.75 m(2), male sex, arterial blood pressure > or = 150 mm Hg, left ventricular ejection fraction < or = 35%, New York Heart Association functional class > or = III, non-sinus rhythm, and prevalent aortic incompetence to be factors influencing LVMR. LVMR was not related to postoperative effective orifice area < or = 0.85 cm/m(2) and prosthetic size. CONCLUSIONS: AVR with a CLOB valve is followed by a significant LVMR that occurs soon after surgery. It is influenced by several patient-related factors: most of them can be predicted preoperatively.     

Left ventricular diastolic dysfunction late after aortic valve replacement in patients with aortic stenosis

Patients with severe aortic stenosis (AS) are known to have increased left ventricular (LV) mass and diastolic dysfunction. It has been suggested that LV mass and diastolic function normalize after aortic valve replacement (AVR). In the present study, change in LV mass index and diastolic function 10 years after AVR for AS was evaluated. Patients who underwent AVR from 1991 to 1993 (n = 57; mean age 67 +/- 8.6 years at AVR, 58% men) were investigated with Doppler echocardiography preoperatively and 2 and 10 years postoperatively. Diastolic function was evaluated by integrating mitral and pulmonary venous flow data. Expected values for each patient, taking age into consideration, were defined using a control group (n = 71; age range 18 to 83 years). Patients were classified into 4 types: normal diastolic function (type A), mild diastolic dysfunction (type B), moderate diastolic dysfunction (type C), and severe diastolic dysfunction (type D). There was a reduction in LV mass index between the preoperative (161 +/- 39 g/m2) and 2-year follow-up (114 +/- 28 g/m2) examinations (p <0.0001), but no further reduction was seen at 10 years (119 +/- 49 g/m2). The percentage of patients with increased LV mass index decreased from 83% preoperatively to 29% at 2-year follow-up (p <0.001). The percentage of patients with moderate to severe LV diastolic dysfunction (types C and D) was unchanged between the preoperative (7%) and 2-year follow-up (13%) examinations (p = 0.27). The percentage of patients increased at 10-year follow-up to 61% (p <0.0001). In conclusion, this reveals the development of moderate to severe diastolic dysfunction 10 years after AVR, despite a reduction in the LV mass index.     

Left ventricular outflow tract pseudoaneurysm after aortic valve replacement: case report

A 68-year-old woman was admitted for angina pectoris and general fatigue without symptoms or signs of infective endocarditis. The patient had undergone re-replacement of an aortic prosthetic valve three months previously. Transesophageal echocardiography revealed an echo-free cavity in the mitral-aortic intervalvular fibrosa region just below the aortic annulus, communication of the echo-free cavity with the left ventricular outflow tract, and turbulent flow into the cavity. Left ventriculography revealed a cavity that arose just below the aortic prosthetic valve, and which expanded in systole and collapsed in diastole. Coronary angiography showed significant stenosis of the proximal right coronary artery, but neither stenoses nor compression were found in the left coronary artery. Patch closure of the pseudoaneurysm and aortic root replacement using a Freestyle valve with reconstruction of the coronary arteries were successfully performed. Surgical trauma to the intervalvular fibrosa during removal of the original prosthetic valve may have caused pseudoaneurysm formation in this patient.     

Left ventricular pseudoaneurysm after mitral valve replacement

Development of left ventricular pseudoaneurysm is a rare complication of mitral valve surgery and requires urgent surgical intervention. We describe a case of pseudoaneurysm of membranous septum following repeat mitral valve replacement with the use of multimodality imaging.     

Left ventricular pseudoaneurysm after mitral valve replacement

We report about a woman with a rare complication after mitral valve replacement 24 years ago. The patient had a massive hemorrhage some hours after operation. We performed invasive diagnostics because of an increasing pressure gradient across the prosthesis and revealed a left ventricular pseudoaneurysm. Before the planned reoperation the patient died suddenly. As the cause of death, we assumed a rupture of the pseudoaneurysm.