Up to thirty-year survival after aortic valve replacement in the small aortic root

Severe aortic stenosis with low transvalvular gradient and severe left ventricular dysfunction:result of aortic valve replacement in 52 patients

BACKGROUND

The outcome of aortic valve replacement in patients with severe aortic stenosis, low transvalvular gradient, and severe left ventricular dysfunction is not well known.

METHODS AND RESULTS

Between 1985 and 1995, 52 patients with left ventricular ejection fraction (EF) < or =35% and aortic stenosis with transvalvular mean gradient <30 mm Hg underwent aortic valve replacement. The mean (+/-SD) preoperative characteristics included EF, 26+/-8%; aortic valve mean gradient, 23+/-4 mm Hg; aortic valve area, 0.7+/-0.2 cm(2); and cardiac output, 3.7+/-1.2 L/min. Simultaneous coronary artery bypass graft surgery was performed in 32 patients (62%). Perioperative (30-day) mortality was 21% (11 of 52 patients). Ten additional patients died during follow-up. Advanced age (P=0.048) and small aortic prosthesis size (P=0.03) were significant predictors of hospital mortality by univariate analysis. By multivariate analysis, the only predictor of surgical mortality was smaller prosthesis size. The only predictor of postoperative survival was improvement in postoperative functional class (P=0.04). Postoperative functional improvement occurred in most patients. Postoperative EF was assessed in 93% of survivors; 74% demonstrated improvement. Positive change in EF was related to smaller preoperative aortic valve area and female sex.

CONCLUSIONS

Despite severe left ventricular dysfunction, low transvalvular mean gradient, and increased operative mortality, aortic valve replacement was associated with improved functional status. Postoperative survival was related to younger patient age and larger aortic prosthesis size, and medium-term survival was related to improved postoperative functional class.

Patient-prosthesis mismatch is negligible with modern small-size aortic valve prostheses

BACKGROUND

Concern has been raised about residual significant gradients when small aortic prostheses are used, particularly in patients with large body surface areas. We studied the performance of six types of small aortic prostheses using dobutamine stress echocardiography.

METHODS

Sixty-three patients (mean age, 67 +/- 7 years) who had undergone aortic valve replacement 17 +/- 6 months previously were studied. Two bileaflet mechanical prostheses (St. Jude Medical and CarboMedics: sizes, 19 mm and 21 mm) and two biological prostheses (Medtronic Intact and St. Jude BioImplant: size, 21 mm) were evaluated. A graded infusion of dobutamine was given and Doppler studies of valve performance were carried out.

RESULTS

All prostheses except one biological valve had acceptable hemodynamic performance under stress. Using regression modeling, gradient at rest was the only variable found to predict gradient under stress (p < 0.001). Moreover, the most important predictor of gradient at rest was valve design, which accounted for 72% of the variance (p < 0.001). This relationship was independent of valve size (19 mm or 21 mm) or material (ie, mechanical or biological). Body surface area accounted for 4% of the variance in gradient only.

CONCLUSIONS

The main predictor of transprosthetic gradient is the inherent characteristics of each particular prosthesis, with relatively insignificant contribution from variations in body surface area. Patient-prosthesis mismatch is not a problem of clinical significance when certain modern valve prostheses are used.

Impact of small prosthetic valve size on operative mortality in elderly patients after aortic valve replacement for aortic stenosis: does gender matter?

OBJECTIVE

Ideal management of the elderly patient with a small aortic root remains controversial. This retrospective analysis was performed to determine whether small prosthetic valve size is related to outcome in patients 70 years of age or older undergoing aortic valve replacement for aortic stenosis.

METHODS

Between December 1991 and July 1998, 366 patients 70 years of age or older (median age 77 years, range 73-81 years, 49% male) underwent isolated aortic valve replacement or aortic valve replacement with coronary bypass grafting with standard Carpentier-Edwards bovine pericardial valves (Baxter Healthcare Corp, Edwards Division, Santa Ana, Calif) (n = 277; 76%) or St Jude Medical mechanical valves (St Jude Medical, Inc, St Paul, Minn) (n = 89; 24%). Propensity scoring and multivariable regression models were used to evaluate the risks associated with implantation of 19-mm valves.

RESULTS

Operative mortality was 16.7% (17/102) in patients who received 19-mm valves and 3% (8/264) among those receiving >/=21-mm valves (P </=.0005). The univariable odds ratio for operative death for 19-mm versus >/=21-mm valves was 6.4 (95% CI 2.7, 15.4; P </=.0005). In the final multivariable model, receipt of a 19-mm valve alone was not a statistically significant predictor of operative death (odds ratio 2. 1; 95% CI 0.7, 6.4; P =.21). However, the combination of male sex and 19-mm valve resulted in a significant risk of operative death (4/9 patients; odds ratio 17.5; 95% CI 2.2, 139; P =.007). Use of a 19-mm valve was not related to late death in either the univariable (hazard ratio 1.0; 95% CI 0.5, 2.0; P =.95) or the multivariable analysis (hazard ratio 0.7; 95% CI 0.3, 1.8; P =.51).

CONCLUSIONS

Implantation of a standard 19-mm aortic valve in elderly men with aortic stenosis may be associated with an increased risk of operative mortality. A higher performance valve and/or a root enlargement procedure should be considered in men with a measured 19-mm anulus.

Performance profile of the Starr-Edwards aortic cloth covered valve, track valve, and silastic ball valve

OBJECTIVE

The Starr-Edwards aortic ball valve has passed 30 years of clinical follow-up. A detailed account of the long-term performance from a large series could thus give valuable guidance in managing patients who are still alive, depict the total remaining life-span after aortic valve replacement (AVR) for the average patient, and set a record yet to be matched by modern disc valves.

METHODS

A detailed follow-up to a maximum of 31.1 years was performed for 717 patients who underwent their first AVR during 1965-1993 with a Starr-Edwards silastic ball valve (N = 355), a cloth covered valve (N = 164) or a track valve (N = 198) with a total of 7254 patient-years at risk.

RESULTS

Patients who received a silastic ball valve were older (average 60 vs. 58 years), had more endocarditis (9%) and more secondary kidney failure (24%) preoperatively than the other patients. The three valve types did not differ as regards long-term survival or freedom from complications and only 15% of late deaths were related to the valve. For the silastic ball valve cumulative freedoms at 10 and 25 years were 59 and 20% from all deaths (crude survival), 85 and 80% from thromboembolism, 87 and 70% from bleeding, 98 and 94% from endocarditis, 96 and 95% from redo AVR and 68 and 51% from all valve related complications joined. There were no instances of structural failure apart from wear of the cloth covering the cage struts of the cloth covered valves. Incidences of haemolysis (0.10%/patient-year) and valve thrombosis (0.06%/patient-year) were low for the silastic ball valve. Analysis of relative survival for the silastic ball valve indicated excess mortality relative to a matched background population only during 1st and 13th postoperative year. Apart from heart related factors and age, independent incremental risk factors for mortality and the various complications included, not valve type, but valve size index (valve size divided by body surface area) < or = 13 mm/m2.

CONCLUSIONS

The Starr-Edwards aortic ball valves, not least the currently available silastic ball valve, are durable through the remaining life time of the patients and able to secure near normal age and sex specific survival provided valve and patient size mismatch is avoided.

A novel comparison of stentless versus stented valves in the small aortic root

BACKGROUND

Previous studies have compared prosthetic valves on the basis of industry-labeled valve sizes. Unfortunately, the relationship between the labeled size and the true measured external or internal diameter differs between valve manufacturers. Therefore hemodynamic comparisons between prosthetic valves are inaccurate if based solely on industry-labeled valve sizes.

METHODS

We have previously demonstrated that the internal diameter of a 21-mm Carpentier-Edwards pericardial stented valve is similar to that of a 25-mm Toronto stentless porcine valve. Therefore we chose to compare postoperative hemodynamics in patients who received 19-, 21-, or 23-mm Carpentier-Edwards pericardial stented valves (inner diameter 18-22 mm, n = 69) with those in patients who received 23- or 25-mm stentless porcine valves (internal diameter 19-21 mm, n = 41).

RESULTS

Patients in the Carpentier-Edwards group were more likely to be elderly and more likely to require concomitant revascularization. Operative mortality was lower in the stentless porcine valve group (0% vs 9%, P =.06). Hospital stay and ventilation requirements were shorter in the stentless porcine valve group. Postoperative hemodynamics were similar in the two groups.

CONCLUSIONS

These data provide evidence that stentless and stented valves have similar hemodynamic profiles in the small aortic root when matched on true measured internal diameters. The clinical benefit of the stentless porcine valve may be due to patient selection or the lack of a rigid stent in the small aortic root, but it is not due to hemodynamic superiority over stented aortic valves of similar sizes.

Multicenter study of stentless valve replacement in the small aortic root

OBJECTIVE

A clinical study was conducted to evaluate the results of stentless porcine valves in patients with a small aortic root (19- and 21-mm aortic anulus).

METHODS

Of 567 patients, from 4 surgical institutions, 171 patients (30.1%) had a small aortic root, comprising 163 cases with calcified aortic stenosis and 8 cases with predominant valvular insufficiency. Sixty patients had associated mitral or coronary lesions. Mean age was 72 +/- 4.2 years. Forty-seven patients with a small aortic root had a 19-mm anulus, and 124 patients had a 21-mm anulus. The body surface area was, respectively, 1.55 +/- 0.2 m2 and 1.78 +/- 0.45 m2. Hemodynamic evaluation of the stentless valve comprised serial measures of mean gradients, effective orifice area, and left ventricular mass reduction. Complication rates for secondary events were evaluated over a 6-year period.

RESULTS

The hospital mortality rate was 3.5%. The mean gradients after the first year were 9 +/- 2 mm Hg and 6 +/- 1.7 mm Hg in patients with a 19-mm and a 21-mm anulus, respectively. Effective orifice area was 1.45 +/- 0.3 cm2 and 1.72 +/- 0.4 cm2. Gradients and surfaces remained stable throughout the study period. Aortic regurgitation was zero to trace. Left ventricular mass at discharge and at 1 year were, respectively, 296 +/- 127 g and 215 +/- 102 g for patients with a 19-mm anulus and 281 +/- 75 g and 236 +/- 15 g for patients with a 21-mm anulus.

CONCLUSIONS

Stentless valves are a suitable device for elderly patients with small aortic roots, which leave only mild residual obstruction.

[Hemodynamic evaluations of patients with small aortic annulus with St. Jude Medical prosthetic heart valve]

As the elderly population in Japan increases, senile degenerative aortic valvular disease also tends to increase. These patients often have a small aortic annulus. The problem of "valve-patient-mismatch" occurs when a small prosthesis is inserted into a patient with a small aortic annulus. To avoid annular enlargement after aortic valve replacement (AVR), we tried to use a small-sized St. Jude Medical (SJM) valve. From September 1988 through November 1996, 110 AVR were performed in our institution. In these cases, 30 underwent AVR with a small sized SJM valve (male < or = 21 mm, female < or = 19 mm). Dobutamine stress echocardiography was performed in 19 patients who had undergone AVR with a small-sized SJM valve. Surgical results were also compared between patients with small aortic annulus and those with normal-sized aortic annulus. Using Doppler echocardiography, pressure gradients (PG), cardiac index (CI), effective orifice area (EOA), and performance index (PI) were calculated at rest and during stress. The mean body surface area (BSA) of patient who had undergone AVR with SJM19A, 19HP and 21A was 1.40, 1.42 and 1.56 m2, respectively. With dobutamine stress, heart rates, PG and CI increased significantly. Mean and maximum PG of patients with 19HP (8.0 and 15.4 mmHg at rest, 12.9 and 28.0 mmHg under stress, respectively) and 21A (9.5 and 19.1 mmHg at rest, 16.5 and 35.3 mmHg under stress, respectively) were relatively low. EOA index (EOAI) of patient with 19HP showed the highest values mean 0.93 cm2/m2. PIs tended to be higher with HP models than with standard models. The tests were completed without significant side effects such as frequent ventricular arrhythmias. Among the cases with small aortic annulus, there were no operative deaths or hospital deaths. There were also no late deaths, episodes of hemorrhage or thrombosis. Conclusions. In our institution, AVR was performed safely without any aortic annular enlargement with a small aortic anulus in small BSA patients. Postoperative hemodynamic data obtained by echocardiography were satisfactory for all patients at rest and even during maximum dobutamine stress test.

Functional evaluation of the bileaflet mechanical valve in the aortic position using dobutamine-stress echocardiography: is a 23-mm prosthetic valve adequately large enough?

The issue of valve prosthesis-patient mismatch in small annular patients is still controversial. The hemodynamic function of bileaflet mechanical valves in the aortic position was examined using dobutamine-stress echocardiography. Forty-four patients were enrolled in the study and divided into 5 groups, according to prosthesis size, from 21 mm to 29 mm. The aortic peak pressure gradient (APG) increased significantly in all groups with dobutamine-stress and exceeded 50 mmHg in 83% of the 21-mm group, in 64% of the 23-mm group, and in 33% of the 25-mm group. The APG even exceeded 80 mmHg in 22% and 18% of the 21-mm and 23-mm groups, respectively. In these cases, the potential of 'valve prosthesis-patient mismatch' was considered. From the relationship between the APG and the prosthesis valve area index (VAI), 'critical VAIs' were found where patients were likely to enter the 'mismatch' status; that is, 1.22 and 1.77 cm2/m2, respectively, for the 5 and 10 microg/kg per min stages of dobutamine stress. This critical VAI range is useful in predicting the 'mismatch' patients preoperatively. Alternative procedures or prostheses should then be selected for them.

Long-Term Follow-Up and Dobutamine Stress Echocardiography of 19-mm Prosthetic Heart Valves

BACKGROUND: In patients with a small aortic root, the use of 19-mm valve prostheses for valve replacement is controversial because of the small orifice area of these valves. METHODS: To assess stress hemodynamics in patients with 19-mm valve prostheses, to find predictors of unfavorable hemodynamics, and to document the long-term follow-up, we examined 30 patients (age, 64 +/- 19 years; 27 women and 3 men; follow-up, 38 +/- 50 months) clinically and with the use of dobutamine stress echocardiography. A history was taken, and a physical examination was performed. At rest and during dobutamine stress, Doppler echocardiography was performed. RESULTS: At rest, transprosthetic gradients were moderately elevated with mean and peak gradients of 15 +/- 7 and 32 +/- 14 mmHg, and effective orifice areas were small (0.91 +/- 0.31 cm(2)). Gradients rose markedly during stress (mean, 37 +/- 14 mmHg; peak, 83 +/- 41 mmHg). Predictors of high transprosthetic gradients were larger body surface area, younger age, and valve type. Mean and peak gradients were lower with St. Jude Medical Hemodynamic Plus valves than with standard St. Jude Medical (P < 0.05) and other valves, and the effective orifice area was highest (1.07 +/- 0.29 cm(2); P < 0.05 versus standard St. Jude Medical) in this valve model. Sixty percent of patients developed significant dynamic subvalvular or intraventricular gradients (84 +/- 41 mmHg) during dobutamine stress. CONCLUSIONS: After aortic valve replacement with 19-mm prostheses in patients with a small aortic root, dobutamine stress leads to high transvalvular gradients, which are dependent on valve model, age, and body surface area. In addition, 60% of patients develop significant dynamic outflow obstructions. These findings and the persistence of some degree of exercise-induced symptoms in 70% of patients suggest that alternative surgical techniques should be considered if the size of the aortic annulus demands a 19-mm valve, especially if the patient seeks physical activity, is young, or is of larger body size.

Left ventricular mass regression after implantation of St. Jude Medical cardiac valves in small aortic roots

In this study, we analyzed the extent of regression of left ventricular hypertrophy in patients who received small St. Jude Medical (SJM) aortic valves and compared the results with those of another group receiving larger valves. Eighty-eight patients received either 19 or 21 mm valves (Group 1, 25 patients) or either 23 or 25 mm valves (Group 2, 53 patients). Echocardiographic studies were done before the operation and 5 years postoperatively. At follow-up a significant reduction in the left ventricular mass was found for both patient groups (p < 0.0001). Doppler echocardiography derived pressure gradients for both groups were obtained during the follow-up period. As expected, the patients in Group 1 had higher peak pressure gradients than did those in Group 2. However, there was no significant difference between the 2 groups or any significant correlations between peak pressure gradients and body surface area (BSA). Actuarial survival was 84.7% at 15 years for Group 1 and 85.9% at 17 years for Group 2. Actuarial freedom from valve related events was 91.4% at 15 years for Group 1 and 82.7% at 17 years for Group 2. There was no significant difference in survival or valve related event free curves between the 2 groups. After implantations of SJM valves in small aortic roots, significant left ventricular mass regression was obtained, and the results were comparable to those for valves of other sizes. The long-term performance of aortic valve replacement with small valves was satisfactory as judged by improvement in the functional class of patients and survival statistics, the durability of the prosthesis, and valve related morbidity comparable to that of valves of other sizes.

Aortic valve replacement for octogenarians: are small valves bad?

BACKGROUND

As the population ages, more octogenarians become candidates for aortic valve replacement. Many octogenarians, particularly women, have a small aortic annulus and there is uncertainty as to the optimal management of this situation in that age group.

METHOD

To examine this issue, we reviewed 248 octogenarians (mean age, 82.6 +/- 2.3 years; 58% men) who underwent primary isolated aortic valve replacement (n = 99), or aortic valve replacement and coronary revascularization (n = 149), between 1980 and 1995. Nineteen-millimeter valves were used in 26% of the patients.

RESULTS

In-hospital mortality was 8.9%, 5% for aortic valve replacement alone and 11.4% for aortic valve replacement and coronary revascularization. It was 12.5% for the 19-mm size valves compared with 7.7% for the bigger size valves (p = 0.24). Follow-up (mean interval, 4.4 years) demonstrated survival for all patients of 85%, 60%, and 30% and survival free from cardiovascular events of 80%, 45%, and 21% at 1, 5, and 10 postoperative years, respectively. Multivariate analysis identified triple-vessel disease and preoperative congestive heart failure as associated with increased risk for both in-hospital and late mortality (p < 0.05). Valve size did not influence late survival or event-free survival regardless of body surface area.

CONCLUSIONS

The use of small aortic valve prostheses in octogenarians does not adversely affect the incidence of early or late mortality or cardiac events.

Aortic valve replacement with a small mechanical valve prosthesis--a clinical and echocardiographic study of a St Jude Medical valve prosthesis

The use of small aortic valve prostheses raises concerns about harmful effects of residual obstruction to left ventricular outflow. The present study was undertaken to examine long-term clinical and echocardiographic results in 193 patients who underwent isolated aortic valve replacement (AVR) with a St Jude Medical (SJM) valve of 25 mm or smaller. The study subjects comprised 128 male and 65 female patients with a mean age of 54.1 years. The patients were divided into 2 groups according to the size of the valve prosthesis used for AVR. Small valves (19 or 21 mm) were implanted in 49 patients (group S) and large valves (23 or 25 mm) were used in 144 patients (group L). The group S patients were mainly female, older, and had smaller body surface areas. There were no significant differences in early and late mortality in group S as compared with group L. Furthermore, there was no difference in the incidence of valve-related or cardiac, non-valve-related death, including the incidence of sudden death, between the 2 groups, and they enjoy a similar level of daily routine activity regardless of the valve size used. Left ventricular (LV) function (ejection fraction, fractional shortening, LV mass index, LV end-systolic volume index, and LV end-diastolic volume index) measured by echocardiography improved significantly and returned to normal values after AVR in both groups. Moreover, no significant differences were observed in the postoperative variables of the LV function. These results suggest that 19-mm and 21-mm SJM valves can be safely used for AVR in the majority of Japanese patients.

The development of valvular heart surgery over the past 50 years (1947-1997): personal recollections

The development of valvular heart surgery over the past 50 years has required the efforts and creative genius of many surgical pioneers. It has been filled with exhilarating short-term successes and some devastating failures. This article traces the 50 years of persistence and determination that have brought us to a time when the majority of patients with heart valve disease can be returned to a happy and fulfilling life by valvuloplasty or by valve replacement.

Long-term follow-up of small (size 20 and 21) Medtronic-Hall aortic valve prostheses

BACKGROUND

Our goal was to study the long-term follow-up of patients having aortic valve replacement and to focus particularly on the patients receiving small prostheses.

METHODS

Four hundred twenty-eight Medtronic-Hall valves were implanted (156 size 20 or 21 mm, 149 size 22 or 23 mm, and 123 size 25 or 27 mm). Group 20-21 had a higher number of female patients, more associated coronary lesions, and more patients with aortic stenosis.

RESULTS

The actuarial survival rate at 8 years was 80% for group 20-21, 80% for group 22-23, and 76% for group 25-27 (p = not significant). In group 20-21, the actuarial event-free rates at 8 years were as follows: thromboembolic complications, 94%; prosthetic valve endocarditis, 99%; reoperation, 98%; and hemorrhagic complications, 78%. The only factors of prognostic value in this group were age and associated coronary lesions.

CONCLUSIONS

The durable nature of the results obtained with the Medtronic-Hall 20- and 21-mm prostheses compared with large-diameter prostheses allows the use of a simple and reliable surgical technique and should mean that indications for ring enlargement become rare.

Extent and pattern of regression of left ventricular hypertrophy in patients with small size CarboMedics aortic valves

OBJECTIVE

To assess the extent and pattern of regression of left ventricular hypertrophy after valve replacement for aortic stenosis, we studied 26 patients receiving either 19 or 21 mm CarboMedics valves (group I, 13 patients) or either 23 or 25 mm CarboMedics valves (group II, 13 patients). The studies were done before the operation and after 3 years, and results were compared with those of 10 control patients.

METHODS

Left ventricular end-diastolic and end-systolic diameters and volumes, ejection fraction and fractional shortening, and interventricular septum and posterior wall thickness were measured. The ratio between interventricular septum and posterior wall thickness, the ratio between left ventricular wall thickness and left ventricular chamber radius, and the left ventricular mass were then calculated.

RESULTS

At follow-up there was a significant reduction in the left ventricular mass, interventricular septum, and posterior wall thickness for both patient groups (p < 0.01). However, only the posterior wall thickness reached normal values; the interventricular septum and the left ventricular mass indices were still significantly greater than in the control group (p < 0.01). Because of the incomplete regression of interventricular septal hypertrophy, the ratio between interventricular septum and posterior wall thickness was similar between both patient groups but it was significantly higher than in control subjects (p < 0.01). The ratio between wall thickness and chamber radius did not decrease significantly in group II patients, in whom it remained above the control values.

CONCLUSION

Having a bileaflet aortic prosthesis of one size larger did not seem to significantly influence the pattern and the extent of regression of left ventricular hypertrophy after an intermediate period of follow-up.

Nineteen-millimeter aortic St. Jude Medical heart valve prosthesis: up to sixteen years' follow-up

BACKGROUND; Prosthetic valve replacement in a small aortic root without annulus enlargement raises concern about its long-term benefits.

METHODS

Between July 1979 and June 1994, 104 (18%) of 593 patients underwent aortic valve replacement using the 19-mm St. Jude Medical heart valve prosthesis. There were 93 women and 11 men, with a mean age of 66.2 +/- 10.6 years. Forty-four patients (42%) were 70 or more years old. The mean body surface area was 1.61 +/- 0.16 m2 (range, 1.2 to 2.1 m2). Forty-nine patients (47%) underwent concomitant procedures; 23 patients (22%) required coronary artery bypass grafts and 25 patients (24%), mitral valve replacement. Ninety-eight patients (94%) presented in New York Heart Association class III and IV.

RESULTS

The operative mortality was 7.6% (8 patients). Follow-up was 100% with a mean of 5.48 +/- 3.73 years (range, 1 to 16 years) and a total of 708 patient-years. There were 18 late deaths, with a mortality of 2.5% patient-years. The incidence of thromboembolism was 0.4% patient-years (3 patients) and anticoagulant-related morbidity was 0.85% patient-years (6 patients). Long-term survival in the two groups with a body surface area of less than 1.7 m2 and 1.7 m2 or more was not statistically different (p = 0.30). The univariate analysis with body surface area as a predictor of mortality showed that a larger body surface area had no effect on the long-term mortality (chi2 p value = 0.36). Survival for 5 and 10 years with the 95% confidence interval was 80.6% +/- 8.3% and 61.6% +/- 15%. Freedom from thromboembolism was 96.3% +/- 4.2% and anticoagulant-related hemorrhage was 91.8% +/- 6.8% at the end of 16 years. Cox proportional hazards model, with time-dependent covariates, showed that events of thromboembolism, anticoagulant-related hemorrhage, and myocardial infarction during follow-up increased the risk of late death (risk ratio, 9.5, 10.3, and 32.8, respectively). The age at operation was an independent risk factor, with decreased survival with age 70 or more years (p = 0.0002). However, body surface area (p = 0.97) and concomitant cardiac procedures (p = 0.86) were not statistically significant predictors of death.

CONCLUSIONS

The long-term performance of the 19-mm St. Jude Medical heart valve prosthesis in the small aortic root is satisfactory irrespective of the body surface area, and it is a viable alternative for such patients.

Left ventricular mass regression early after aortic valve replacement

BACKGROUND

Regression of left ventricular hypertrophy is an important and well-recognized salutary effect of aortic valve replacement. The earliest evidence of left ventricular mass regression after aortic valve replacement and the influence of prosthesis type are not well known, and were the focus of this study.

METHODS

Transthoracic echocardiography was used to measure left ventricular mass index preoperatively and before discharge in 57 consecutive patients undergoing isolated aortic valve replacement (with or without coronary artery bypass grafting).

RESULTS

Three patients were excluded from the study because of inability to obtain accurate M-mode echocardiographic images for left ventricular mass measurement preoperatively (1) or postoperatively (2). Of the remaining 54 patients, mechanical bileaflet valves were used in 19, stented tissue bioprostheses were implanted in 15, and a stentless porcine bioprosthesis was chosen for 20. Postoperative echocardiograms were obtained 4.9 +/- 2.3 days after aortic valve replacement (range, 2 to 9 days). A two-way repeated-measures analysis of variance demonstrated a significant reduction of left ventricular mass index before discharge (preoperative 141.4 +/- 45.2 g/m2, postoperative 127.5 +/- 32.8 g/m2; p = 0.0005) but no differences between prostheses.

CONCLUSIONS

Left ventricular mass regression begins early after aortic valve replacement, probably because of reduction of transvalvular gradients and left ventricular wall stress. At least in the very early postoperative period, the type of prosthesis does not influence the extent of mass regression.

Aortic valve replacement in elderly patients: influence of concomitant coronary grafting on late survival

BACKGROUND

Aortic valve replacement (AVR) has been an accepted therapy for elderly patients (> 70 years) with aortic valve disease. This study was designed to investigate the determinants of survival after the implantation of aortic valve prostheses, with emphasis on the effect of concomitant coronary artery bypass grafting on survival.

METHODS

From November 1964 to July 1994,963 elderly patients underwent isolated AVR. Long-term survival was investigated in 877 patients (70 to 94 years) who survived operation, with 92% follow-up completeness (mean +/- standard deviation, 4.5 +/- 3.9 years; maximum, 20.1 years; total, 3,920.2 patient-years), by univariate and multivariate analyses.

RESULTS

Actuarial survival was 38.1% +/- 2.8% at 10 years, 17.8% +/- 3.0% at 15 years, and 9.0% +/- 3.1% at 20 years. Eight variables (age, sex, body surface area [less or greater than 1.7 m2], period of operation, type of prosthesis, size of prosthesis, re-replacement, and concomitant coronary artery bypass grafting) were investigated with regard to long-term survival by the Kaplan-Meier method. Age, sex, and body surface area were significant. Multivariate analysis revealed that older age (p = 0.0005) and male sex (p = 0.0001) were independent variables that determined long-term survival.

CONCLUSIONS

Elderly patients may have satisfactory long-term results after AVR. Age and sex are independent determinants. Other factors (such as concomitant coronary artery bypass grafting and type of prosthesis) did not independently influence long-term survival. Coronary revascularization in elderly patients with coronary disease undergoing AVR may lead to a long-term survival similar to that in patients without coronary disease undergoing AVR.