Early in vivo experience with the Hemodynamic Plus St. Jude Medical heart valves in patients with narrowed aortic annulus

Aortic Valve Replacement without Annular Enlargement in Patients with Small Aortic Roots

Use of small prostheses for aortic valve replacement eliminates the need for annular enlargement but may impair symptomatic resolution and long-term patient survival. We reviewed our experience with 105 consecutive patients who had isolated aortic valve replacement with small mechanical prostheses or bioprostheses (14 to 21 mm) without concurrent annular enlargement between August 1976 and November 1992. The mean age was 72 ± 10 years and 82% of patients were female. Valvular disease was primarily aortic stenosis in 61%, aortic regurgitation in 7%, and mixed aortic disease was present in 32% of patients. Mean preoperative ejection fraction was 64% ± 17% and the aortic valve area was 0.5 ± 0.2 cm2. Prior to surgery, 82% of patients were in New York Heart Association functional class III or IV. The mean duration of follow-up was 8.1 years. There were 7 early and 14 late deaths giving an overall survival of 80% and a 10-year Kaplan-Meier survival rate of 77%. Five patients developed thromboembolic complications (transient stroke) and 2 required repeat aortic valve replacement due to prosthetic valve endocarditis. Doppler echocardiography or cardiac catheterization was performed in 15 patients postoperatively but peak systolic gradient exceeded 50 mm Hg in only one individual with a 21-mm porcine valve. All surviving patients were in functional class I or II. We conclude that aortic valve replacement with small prostheses is associated with excellent long-term patient survival, improvement in clinical symptoms, and a low incidence of complications.

Early and Midterm Results of Aortic Annular Enlargement

From November 1987 to May 1998, 16 patients with a small aortic annulus underwent patch enlargement of the aortic valve by Nicks' technique (in 9) or Manouguian's method (in 7). The mean age of the patients was 40 years (range, 22 to 58 years), mean body surface area was 1.54 m2 (range, 0.95 to 2.05 m2), and 11 were female. Concomitant procedures were mitral valve replacement in 4 cases, tricuspid commissurotomy and De Vega annuloplasty in 2, and one case each of patent ductus arteriosus ligation and coronary bypass. Aortic annular sizes were 15 to 19 mm (mean, 17.4 mm) preoperatively and 20 to 24 mm (mean, 22.1 mm) after the procedure. Two patients (12.5%) died in the early postoperative period. Peak pressure gradients across the prostheses were 15 to 22 mm Hg (mean, 19.4 mm Hg) on echocardiography. The mean duration of follow-up was 32.85 months (3 months to 8 years) and it was 92.8% complete. There were no late deaths. Mitral valve function was good except in one patient who had minimal mitral regurgitation after Manouguian's procedure. Both methods were found to be effective and reliable and should be performed when there is a risk of patient-prosthesis mismatch.

Does the St. Jude Regent 17-mm Offer Better Outcomes Than the Hemodynamic Plus 17-mm Aortic Valve Mechanical Prothesis?

OBJECTIVE

The aim of the present study is to report the early and mid-term clinical and hemodynamic results of a prospective trial investigating the clinical performance of the St. Jude Medical Regent 17 mm (SJMR-17) versus St. Jude Medical Hemodynamic Plus 17 mm (SJMHP-17).

MATERIALS AND METHODS

Between January 2000 and August 2013, 20 patients (Group I) with aortic valve (AV) stenosis underwent first time AV replacement with a SJMR-17 and nine patients (Group II) underwent AV replacement with a SJMHP-17. The mean follow-up was 58 ± 31 months.

RESULTS

There was one death in Group I. The end-diastolic IVS thickness and end-systolic posterior left ventricle (LV) wall thickness was reduced significantly in boths groups (p = 0.001 and p = 0.006 in Group I and p = 0.007 and p = 0.011 in Group II). The peak and mean transprosthesis gradients (P-TPG and M-TPG) were 29 ± 6.8 mmHg and 17.5 ± 4.5 mmHg in Group I, significantly lower than in Group II (55.2 ± 19.7 mmHg and 28.8 ± 7.7 mmHg). The postoperative left ventricular mass (LVM) and indexed left ventricular mass (LVMi) were reduced significantly in both groups versus the preoperative values. The postoperative LVMi was 114.5 ± 10.6 g/m(2) in Group I versus 127 ± 8 g/m(2) in Group II (p = 0.01). With dobutamine, heart rate, left ventricular ejection fraction, cardiac output, transprosthesis peak, and mean gradients increased significantly in both groups, however, the P-TPG and M-TPG were significantly higher in Group II (p = 0.026 and p = 0.022) despite a non-significant increase of the indexed effective orifice area.

CONCLUSIONS

The SJMR-17 can be employed with satisfactory postoperative clinical and hemodynamic outcomes in patients with small aortic annulus, especially in elderly patients offering better outcome than SJMHP-17.

Diagnostic evaluation of left-sided prosthetic heart valve dysfunction

Prosthetic heart valve (PHV) dysfunction is a rare, but potentially life-threatening, complication. In clinical practice, PHV dysfunction poses a diagnostic dilemma. Echocardiography and fluoroscopy are the imaging techniques of choice and are routinely used in daily practice. However, these techniques sometimes fail to determine the specific cause of PHV dysfunction, which is crucial to the selection of the appropriate treatment strategy. Multidetector-row CT (MDCT) can be of additional value in diagnosing the specific cause of PHV dysfunction and provides valuable complimentary information for surgical planning in case of reoperation. Cardiac magnetic resonance imaging (CMR) has limited value in the evaluation of biological PHV dysfunction. In this Review, we discuss the use of established imaging modalities for the detection of left-sided mechanical and biological PHV dysfunction and discuss the complementary role of MDCT in this context.

Does Aortic Root Enlargement Impair the Outcome of Patients With Small Aortic Root?

BACKGROUND

Posterior root enlargement procedures provide the implantation of suitable-sized prosthetic valves in patients with a small aortic root to prevent a high postoperative transvalvular gradient. The aim of this study was to evaluate long-term results of the posterior root enlargement.

METHODS

Between 1985 and 2002, 124 patients underwent aortic valve replacement with a posterior root enlargement. The main indication was a small aortic valve orifice area to patient body surface area (indexed valve area < 0.85 cm2/m2). Fifty-four (44%) patients were male, and 70 (56%) were female with a mean age 39.1 +/- 14.3 years. Indications for operation were severe calcified aortic valve stenosis (37.1%), severe aortic insufficiency (25.8%), or combination (37.1%). Seventy-five (60%) patients received double-valve replacement. A pericardial patch was used in 100 patients (80.6%) and a Dacron patch was used in 24 patients.

RESULTS

Operative mortality was 6.4% (8 patients). The causes of hospital mortality were low cardiac output syndrome (LCOS) (in 6 patients), cerebrovascular events (in 1 patient) and multiple organ failure (in 1 patient). Multivariate analysis demonstrated concomitant coronary revascularization to be a significant (p = 0.03) predictor for early mortality. There were six (5.4%) late deaths. Cox proportional hazards regression analysis demonstrated LCOS (p = 0.013) and infective endocarditis (p = 0.003) to be significant predictors for late mortality. Atrioventricular block required a permanent pacemaker was observed in 4 patients (3.2%).

CONCLUSIONS

Posterior aortic root enlargement techniques can be easily applied without additional risks. Long-term survival and freedoms from valve-related complications are satisfactory.

Prosthesis-Patient Mismatch After Aortic Valve Replacement: Impact of Age and Body Size on Late Survival

BACKGROUND

The purpose of this study was to identify patient subgroups in which prosthesis-patient mismatch most influenced late survival.

METHODS

Over a 12-year period, 1,400 consecutive patients underwent bioprosthetic (933 patients) or mechanical (467) aortic valve replacement. Prosthesis-patient mismatch was defined as prosthetic effective orifice area/body surface area less than 0.75 cm2/m2 and was present with 11% mechanical and 51% bioprosthetic valves.

RESULTS

With bioprosthetic valves, prosthesis-patient mismatch was associated with impaired survival for patients less than 60 years old (10-year: 68% +/- 7% mismatch versus 75% +/- 7% no mismatch, p < 0.02) but not older patients (p = 0.47). Similarly, with mechanical valves, prosthesis-patient mismatch was associated with impaired survival for patients less than 60 years old (10-year: 62% +/- 11% versus 79% +/- 4%, p < 0.005) but not older patients (p = 0.26). For small patients (body surface area less than 1.7 m2), prosthesis-patient mismatch did not impact survival with bioprosthetic (p = 0.32) or mechanical (p = 0.71) valves. For average-size patients (body surface area 1.7 to 2.1 m2), prosthesis-patient mismatch was associated with impaired survival with both bioprosthetic (p < 0.05) and mechanical (p < 0.005) valves. For large patients (body surface area greater than 2.1 m2), prosthesis-patient mismatch was associated with impaired survival with mechanical (p < 0.04) but not bioprosthetic (p = 0.40) valves.

CONCLUSIONS

Prosthesis-patient mismatch had a negative impact on survival for young patients, but its impact on older patients was minimal. In addition, although prosthesis-patient mismatch was not important in small patients, prosthesis-patient mismatch negatively impacted survival for average-size patients and for large patients with mechanical valves.

Left ventricular mass index reduction early after an isolated aortic valve replacement with St. Jude Medical 19A-HP

OBJECTIVES

It has been reported that the left ventricular mass index (LVMI) for the hypertrophic myocardium is reduced at an early stage following surgery. In this study, those factors affecting the changes in early postoperative LVMI were investigated in cases in which a St. Jude Medical 19A-HP (19HP) mechanical heart valve was used.

METHODS

We studied 16 consecutive patients with pure aortic stenosis undergoing isolated aortic valve replacement using a 19HP between January 1994 and July 2001. The patients were all female, aged 64 +/- 6 years, with a body surface area of 1.44 +/- 0.10 m2 and preoperative New York Heart Association (NYHA) classification of 2.2 +/- 0.5. All patients underwent transthoracic echocardiography at 4.2 +/- 3.3 days before and 16.3 +/- 10.2 days after operation, and cardiac catheterization within a mean period of one month before operation. The correlations between the decrease of LVMI at 16.3 +/- 10.2 days after operation and perioperative parameters were determined.

RESULTS

There was significant LVMI regression postoperatively (15 +/- 12%, p = 0.01), and only a significant negative correlation between the decrease of LVMI and preoperative left ventricular pressure (LVp) [r = -0.74, p < 0.01]. There was no effective LVMI reduction in the high preoperative LVp group (> or = 210 mmHg).

CONCLUSION

It is expected that in the high LVp group, huge wall stress was being applied to the left ventricular muscle immediately before surgery and in the early period after surgery. Preoperative LVp is an important index for determining the surgical timing and safe perioperative management. We recommend early surgical treatment before LVp becomes more than 210 mmHg.

A comparison of the in vivo performance of the 19-mm St. Jude Medical Hemodynamic Plus and 21-mm standard valve

BACKGROUND

In the present study we analyzed the in vivo performance of the 19-mm St. Jude Medical Hemodynamic Plus aortic prosthesis (19HP), evaluated the midterm performance of 19HP in the aortic position, and compared the implantability and hemodynamic characteristics of this valve with those of the 21-mm standard St. Jude Medical valve (21SD) in adult patients with aortic stenosis and a narrowed aortic annulus.

METHODS

From February 1994 to December 1999, 60 patients who underwent isolated aortic valve replacement with either the 19HP (n = 31) or the 21SD (n = 29) were studied. Comparison between the two models included analysis of early and late mortality and morbidity. Pre- and postoperative echocardiography was performed in all patients to evaluate and compare the hemodynamic performance of both prosthetic valves. The postoperative serum lactic dehydrogenase activity was measured in both groups of patients as an indicator of hemolysis.

RESULTS

The mean body surface area was 1.46 +/- 0.16 m2 in the 19HP group and 1.49 +/- 0.13 m2 in the 21SD group (p = 0.1577). Other than female dominance in the 19HP group, there was no statistically significant difference between the two groups in terms of preoperative variables (age, preoperative pressure gradients, and New York Heart Association functional class). The average postoperative peak pressure gradient was 23.3 +/- 10.5 mm Hg in the 19HP group and 27.9 +/- 9.9 mm Hg in the 21SD group (p = 0.0666). There was no hospital death in either group. Six-year follow-up was completed in both groups of patients. Late death occurred in 1 patient in the 19HP group (1.09% per patient-year). Actuarial survival at 6 years was 92.3% +/- 7.4% in the 19HP group, and 100% in the 21SD group (p = 0.33). The linearized complication rate was 1.09% per patient-year and 1.02% per patient-year for thromboembolism, and 1.09% per patient-year and 1.02% per patient-year for anticoagulant-related hemorrhage in the 19HP group and the 21SD group, respectively. Freedom from all complications at 6 years did not show any significant difference between the two groups (p = 0.54). Although left ventricular mass indices decreased significantly after aortic valve replacement in both groups (19HP group, p = 0.0002; 21SD group, p = 0.0006), there were no significant differences in the two indices between the groups after aortic valve replacement (p = 0.999). There was no significant difference in the lactic dehydrogenase level between the two groups (p = 0.4915).

CONCLUSIONS

In vivo hemodynamic performance of the 19HP valve as well as the early and intermediate clinical outcome up to 6 years was satisfactory and corresponded closely to that of the 21SD valve in adult patients. The 19-mm Hemodynamic Plus model can be recommended in patients with a measured 19-mm annulus and this valve will minimize the need for the aortic annular enlargement procedure.

Replacement of a thrombosed valve after the Bentall procedure

A 50-year-old man developed thrombosis in the valve of a Björk-Shiley prosthesis that had been used for composite graft replacement of the aortic valve and ascending aorta 8 years previously. The thrombosed valve was removed, and because of the narrow aortic valve ring, it was replaced using patch enlargement of the aortic annulus without replacement of the conduit.

Clinical evaluation of St Jude Medical Hemodynamic Plus versus standard aortic valve prostheses: The Italian multicenter, prospective, randomized study

OBJECTIVE

Hemodynamic and clinical performances of 21-mm and 23-mm St Jude Medical Hemodynamic Plus aortic valves (St Jude Medical, Inc, St Paul, Minn) were compared with those of 21-mm and 23-mm St Jude Medical standard cuff aortic valves in the first such multicenter, prospective, randomized study. Hemodynamic Plus valves are mechanical, bileaflet prostheses suitable for the small aortic anulus.

METHODS

Patients with 21-mm and 23-mm anulus diameters were randomized to receive either a Hemodynamic Plus or a standard cuff valve. Postoperatively and at 6 months after the operation, patients underwent 2-dimensional Doppler echocardiography. Ejection fraction, cardiac output, peak gradient, mean gradient, effective orifice area, effective area index, and performance index were calculated. Postoperative and 6-month echocardiographic measurements and their variations across observation times were analyzed statistically.

RESULTS

Of the 140 patients enrolled, 5 died at operation and 1 died of aortic dissection during the follow-up period. Eight patients were lost to follow-up. A total of 125 patients completed the study. In 1 patient a sewing cuff escaped intraoperatively. At 6 months the 21-mm and 23-mm Hemodynamic Plus valves showed significantly lower peak gradients and mean gradients than those of the 21-mm and 23-mm standard cuff valves. The 21-mm Hemodynamic Plus valves had gradients similar to those of the 23-mm Hemodynamic Plus valves. The effective orifice area did not differ significantly between the Hemodynamic Plus and standard cuff valves at either measurement. No valve mismatch was found in the 4 groups of patients. A more enhanced decrease of peak gradients and mean gradients and a more enhanced increase of effective orifice areas, effective area indices, and performance indices were found across observation times for patients with Hemodynamic Plus valves compared with those with standard cuff valves.

CONCLUSIONS

Clinical hemodynamic performances of 21-mm and 23-mm St Jude Medical Hemodynamic Plus valves correspond closely with those of standard cuff valves, and gradients are substantially better than those of standard cuff valves of the same diameter. Therefore, use of this valve may minimize the need for aortic anulus enlargement. Early follow-up results with the Hemodynamic Plus valves were excellent, although more time is required to confirm this outcome.

Hemodynamic and clinical impact of prosthesis-patient mismatch in the aortic valve position and its prevention

Prosthesis-patient mismatch is present when the effective orifice area of the inserted prosthetic valve is less than that of a normal human valve. This is a frequent problem in patients undergoing aortic valve replacement, and its main hemodynamic consequence is the generation of high transvalvular gradients through normally functioning prosthetic valves. The purposes of this report are to present an update on the concept of aortic prosthesis-patient mismatch and to review the present knowledge with regard to its impact on hemodynamic status, functional capacity, morbidity and mortality. Also, we propose a simple approach for the prevention and clinical management of this phenomenon because it can be largely avoided if certain simple factors are taken into consideration before the operation.

[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.

Pseudoabscess of the aortic root caused by ectopic seating of an aortic prosthesis

An approach to some of the technical problems involved in aortic valve replacement includes positioning of some or all of the prosthetic ring in a position ectopic to the true aortic annulus. Such placement can create the apparent appearance of an echolucent region adjacent to the prosthetic ring that shows flow on color Doppler interrogation to suggest the presence of an abscess cavity. This case demonstrates how such a pseudoabscess can be created and the clinical and echocardiographic clues that were used to make the correct diagnosis.

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.

Medium-Term Outcome with Small Size ATS Medical Valves in Aortic Position

Records of 33 patients (group 1) who received 19-mm or 21-mm ATS aortic valve prostheses were retrospectively reviewed and compared with those of 26 patients who received 25-mm ATS valves (group 2). Group 1 patients were younger (20 ± 2 years versus 43 ± 15 years) and had a smaller mean body surface area (1.6 m2 versus 1.83 m2). Valve pathology was usually congenital aortic stenosis in group 1 and rheumatic in group 2. There was no operative mortality. The mean postoperative Doppler resting gradient was higher in group 1 (21 mm Hg versus 7 mm Hg). Total follow-up was 294 patient-years. There was no perivalvular leak, valve thrombosis, or endocarditis in either group. In group 2, there was 1 anticoagulant-related hemorrhage and 1 late death due to congestive heart failure. We concluded that in spite of the higher transprosthetic gradient, 19-mm and 21-mm ATS aortic valve prostheses performed satisfactorily in adult patients with a body surface area of less than 1.6 m2. This valve can be used in a small aortic annulus as an alternative to performing an annular enlargement procedure.

Hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve

The hemodynamic performance of the St. Jude Medical Hemodynamic Plus valve (HP) for a small aortic annulus was compared to that of the standard St. Jude Medical valve (SJM). Doppler echocardiographic parameters were evaluated in patients undergoing aortic valve replacement with either a 19 mm HP (HP19, n = 7), a 21 mm HP (HP21, n = 8), a 19 mm SJM (SJM19, n = 16), or a 21 mm SJM (SJM21, n = 34). The peak and mean pressure gradients and peak flow velocity were significantly (p < 0.05) lower in both patients with the HP21 and those with the HP19 than patients with the SJM21 and those with the SJM19, respectively. The echocardiographic parameters of the patients with the HP19 corresponded closely to those of patients with the SJM21. The left ventricular mass index regressed markedly in patients with the HP19 during the late postoperative period. The results suggested that the hemodynamic performances of certain sizes of the HP were superior to those of the same size SJMs and were considered to be equivalent to those of the next size larger SJM.