Aortic Valve Replacement With the St. Jude Medical Prosthesis and Fixed Dose Anticoagulation

A bstract Over a 10-year period, between 1986 and 1996, 865 patients underwent primary aortic valve replacement (AVR) with the St. Jude Medical mechanical prosthesis. Patients who had undergone valve replacement with a different type of prosthesis previously were excluded from this study. Patient age ranged from 11 to 79 years. The mean age was 42.9 ± 14.54. The gender distribution was 396 men (45.8%) and 469 women (54.2%). All patients received 2.5 mg/day Coumadin after extubation. A combination of the antiagregant therapy (Dypridamole 3 × 75 mg/day, Asprine 100 mg/day) was added after removal of the chest tubes. The dosage of Coumadin was maintained constant regardless of the prothrombin time (PT) or cardiac rhythm. There were 101 valve-related complications (4.2% per patient year [ppy]) occurring in the late follow-up period. Of these complications; 38 were anticoagulant-related hemorrhage (1.58% ppy), 3 were paravalvular leak (0.12% ppy), and 36 were thromboembolism (1.4% ppy). There were 24 reoperations (0.99% ppy) and 17 late deaths. The linearized late mortality rate was 0.7% ppy. Long-term survival estimates at 5 and 10 years were 97.14 ± 0.82% and 94.86 ± 1.54%, respectively. We conclude from the data that the St. Jude Medical valve may allow the use of a low level of anticoagulation. This study shows that fixed dose oral anticoagulation does not increase the rate of thromboembolism in patients with the St. Jude aortic valve. This protocol does not result in reduction of bleeding complications, however.     

Hernodynamic Performance of the St. Jude Medical Hemodynamic Plus Valve

Abstract: 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 = 71, a 21 mm HP (HP21, n = S), a 19 mm SJM (SJM19, n = 16), or a 21 mm SJM (SJM21, n = 34). The peak and mean pres sure 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 sue SJMs and were considered to be equivalent to those of the next size larger SJM.     

Aortic and mitral valve replacement with the St. Jude Medical prosthesis

From April 1, 1979 to August 31, 1983, 228 patients underwent isolated aortic (AVR) (118) or mitral (MVR) (90) valve replacements with a new tilting disc valve prosthesis, the St. Jude prosthesis, at the Medical University of South Carolina. Age ranged from 6 to 84 years (mean 49.1 +/- 19.2 AVR, 44.5 +/- 16.5 MVR). Male sex predominated in the AVR group (68%) and female sex in the MVR group (68%). Thirty-five patients (16.8%) had associated coronary bypass surgery (AVR 23.7%, MVR 7.8%). There were seven deaths (3.4%) occurring during the same hospitalization (AVR: 3/118, 2.5%; MVR: 4/90, 4.4%). Follow-up is 97.6% complete and ranges from 1 to 54 months (mean 19.6 +/- 12.4). In the AVR group, nine late deaths have occurred and actuarial survival at 42 months is 86.7 +/- 3.8%. Three patients have sustained thromboembolic episodes for a linearized rate of 1.6% patient-year, and the probability of remaining free of thromboembolism at 42 months is 96.9 +/- 1.8%. The mean improvement in functional class from preoperative to postoperative is 3.1 +/- 0.7 to 1.2 +/- 0.4 (p less than 0.001). In the MVR group, there have been four late deaths, and the actuarial survival at 42 months is 89.3 +/- 3.8%. Two patients have sustained thromboembolic complications for a linearized rate of 1.2%/patient-year, and the probability of remaining free of thromboembolism at 42 months is 97.2 +/- 2%. The mean improvement in functional class from before to after surgery is 3.2 +/- 0.7 to 1.3 +/- 0.5 (p less than 0.001). There have been no thromboses of the St. Jude valve in the mitral or aortic position, no mechanical failures, and no patient has had significant valve-related hemolysis. Because of this experience, the St. Jude Medical heart valve prosthesis is our prosthesis of choice for any patient undergoing valve replacement with a mechanical prosthesis.     

Valve thrombosis of St. Jude Medical prosthesis; report of three cases

Three cases with valve thrombosis of St. Jude Medical prosthesis (SJM valve) are reported. Incidence of valve thrombosis of SJM valve was 0.15%/patient-year. Cineradiography was useful to make the diagnosis. SJM valves were implanted with the hinges anatomically oriented in mitral position, and in both aortic and tricuspid positions with the leaflet opening parallel to the ventricular septum. Therefore, we recommend that SJM valve should be placed with the hinge antianatomically oriented in mitral position, and in both aortic and tricuspid positions with the leaflet opening to be perpendicular to the interventricular septum, respectively.     

A Morphologic Study of Two Types of Porcine Valve Bioprostheses: Comparison of Aortic Wall Thickness

Outer aortic wall morphology and thickness were compared in the Hancock porcine aortic bioprosthesis and the Carpentier-Edwards porcine aortic bioprosthesis. The overall average aortic wall thickness, the average maximum thickness, the average minimum thickness, and the average variation in aortic wall thickness were greater in the Hancock valve. Differences in preparation technique accounted for the disparities. The tunica adventitia and variable amounts of the outer tunica media were generally removed during processing of the Carpentier-Edwards valve prior to mounting in the stent. The removal of this tissue at times exposed the deeper collagenous cusp anchor at the commissures. Possible implications of these differences are briefly considered.     

Malfunction of a St. Jude Medical Heart Valve in Mitral Position

Early postoperative intermittent malfunction in a St. Jude mitral valve prosthesis is described. The patient underwent reoperation and had an uneventful recovery. After explantation, the prosthesis underwent laboratory examination. The findings included a minimal disproportion between leaflets and valve ring causing intermittent inhibition of leaflet motion. The unpredictable irregularity of the malfunction phenomenon in vivo, confirmed by laboratory investigations, is explained as a result of a changing myocardial tension status sufficient to alter the ring to leaflet proportion of the valve in either direction.     

The necessity of reoperation for patients with Bjork-Shiley, St Jude Medical, Hancock and Carpentier-Edwards prostheses

The purpose of this study was to determine the criteria of valve selection from the long-term results of Hancock, Carpentier-Edwards, St Jude Medical and Bjork-Shiley prostheses, taking into special account the frequency of reoperation. Reoperations on the Hancock bioprosthesis were performed on six patients for tissue leaflet disruption with an incidence of 2.2 per cent/patient-year. Reoperations on the Carpentier-Edwards bioprosthesis were performed on 24 patients for tissue leaflet disruption in 23 patients and prosthetic valve endocarditis (PVE) in one, with an incidence of 3.8 per cent/patient-year. Reoperations on the Bjork-Shiley prosthesis were performed in two patients for severe hemolysis, with an incidence of 0.32 per cent/patient-year. Reoperations on the St Jude Medical prosthesis were performed on 3 patients, for valve thrombosis in one patient, PVE in one, and hemolysis in one, with an incidence of 0.23 per cent/patient-year. The overall mortality rate was 20 per cent, or 7 patients, and the indications for reoperation affected this. Patients with primary tissue failure had a mortality rate of 10.3 per cent; those with a thrombosed valve, 0 per cent; those with hemolysis, 66.7 per cent; and those with valve infection, 100 per cent. A good chance of survival may be achieved in patients facing prosthetic valve complications by performing reoperation as soon as possible after early detection, since mortality is high following emergency reoperation and in patients with severe symptoms. Currently, we recommend mechanical prostheses for valve replacement except in patients over 70 years old and in younger patients with absolute contraindications to anticoagulative therapy.     

The necessity of reoperation for patients with Bjork-Shiley,St Jude Medical,Hancock and Carpentier-Edwards prostheses

The purpose of this study was to determine the criteria of valve selection from the long-term results of Hancock, Carpentier-Edwards, St Jude Medical and Bjork-Shiley prostheses, taking into special account the frequency of reoperation. Reoperations on the Hancock bioprosthesis were performed on six patients for tissue leaflet disruption with an incidence of 2.2 per cent/patient-year. Reoperations on the Carpentier-Edwards bioprosthesis were performed on 24 patients for tissue leaflet disruption in 23 patients and prosthetic valve endocarditis (PVE) in one, with an incidence of 3.8 per cent/patient-year. Reoperations on the Bjork-Shiley prosthesis were performed in two patients for severe hemolysis, with an incidence of 0.32 per cent/patient-year. Reoperations on the St Jude Medical prosthesis were performed on 3 patients, for valve thrombosis in one patient, PVE in one, and hemolysis in one, with an incidence of 0.23 per cent/patient-year. The overall mortality rate was 20 per cent, or 7 patients, and the indications for reoperation affected this. Patients with primary tissue failure had a mortality rate of 10.3 per cent; those with a thrombosed valve, 0 per cent; those with hemolysis, 66.7 per cent; and those with valve infection, 100 per cent. A good chance of survival may be achieved in patients facing prosthetic valve complications by performing reoperation as soon as possible after early detection, since mortality is high following emergency reoperation and in patients with severe symptoms. Currently, we recommend mechanical prostheses for valve replacement except in patients over 70 years old and in younger patients with absolute contraindications to anticoagulative therapy.     

Evaluation of St. Jude Medical Mitral Valve Function by Exercise Doppler Echocardiography

ABSTRACT The aim of this study was to detect borderline mitral valve dysfunction in 100 asymptomatic patients with a St. Jude Medical valve. We studied rest and exercise hemodynamics by Doppler echocardiography. Study patients were divided into two groups according to the time since surgery: group A had valves implanted less than 5 years ago (44 patients), group B had valves implanted more than 5 years ago (56 patients). Although patients had no clinical signs of valve dysfunction, group B was found to have significant reduction of mitral valve area (p < 0.05). In the group A patients, mean gradients at rest increased from 4 ± 2, 4 ± 2, and 3 ± 1 mmHg in valve sizes of 25, 27, and 29 mm, respectively, to 7 ± 2, 7 ± 3, and 5 ± 2 mmHg with exercise. In the group B patients, mean gradients at rest increased from 7 ± 1, 6 ± 2, and 5 ± 1 mmHg to 14 ± 3, 13 ± 3, and 10 ± 4 mmHg, respectively, after exercise. The percent increase (mean) in peak pressure gradient with exercise was significantly higher in group B (more than 100%) than in group A (less than 80%) (p < 0.01). The percent increase in mean gradient with exercise was also significantly higher in group B (more than 100%) than in group A (less than 75%). In conclusion, patients with reduced valve area and more than a 100% increase of peak and mean gradients should be followed up carefully. If any signs or symptoms of heart failure develop, they must be considered as candidates for surgery.     

Risk of Reoperative Valve Replacement for Failed Mitral and Aortic Bioprostheses

Background. One factor influencing the choice of mechanical versus bioprosthetic valves is reoperation for bioprosthetic valve failure. To define its operative risk, we reviewed our results with valve reoperation for bioprosthetic valve failure.

Methods. Records of 400 consecutive patients having reoperative mitral, aortic, or mitral and aortic bioprosthetic valve replacement from January 1985 to March 1997 were reviewed.

Results. Reoperations were for failed bioprosthetic mitral valves in 219 patients, failed aortic valves in 153 patients, and failed aortic and mitral valves in 28 patients. Including 26 operations (6%) for acute endocarditis, 153 operations (38%) were nonelective. One hundred nine patients (27%) had other valves repaired or replaced, and 72 (18%) had coronary bypass grafting. The incidence of death in the mitral, aortic, and double-valve groups was respectively, 15 (6.8%), 12 (7.8%), and 4 (14.3%); and the incidence of prolonged postoperative hospital stay (>14 days) was, respectively, 57 (26.0%), 41 (26.8%), and 8 (28.6%). Only 7 of 147 patients (4.8%) having elective, isolated, first-time valve reoperation died. Multivariable predictors (p < 0.05) of hospital death were age greater than 65 years, male sex, renal insufficiency, and nonelective operation; and predictors of prolonged stay were acute endocarditis, renal insufficiency, any concurrent cardiac operation, and elevated pulmonary artery systolic pressure.

Conclusions. Reoperative bioprosthetic valve replacement can be performed with acceptable mortality and hospital stay. The best results are achieved with elective valve replacement, without concurrent cardiac procedures.     

St. Jude SPV Versus Medtronic Freestyle: A Single Institution Comparison of Two Stentless Aortic Valves

BACKGROUND: Improved hemodynamics with the SPV and Freestyle bioprostheses compared to stented valves have been reported. It has been suggested that there is more aortic insufficiency (Al) with the Freestyle than with the SPV valve. This study was designed to assess the hemodynamic performance of these two valves implanted at a single institution with all echocardiograms reviewed by one echocardiographer. METHODS: From 1993 to 1997 112 patients underwent aortic valve replacement with stentless aortic valves (69 SPV, 43 Freestyle). There were no major preoperative differences in patient age, gender, NYHA class, or ejection fraction between groups. Echocardiographic assessment was obtained at discharge, 3 to 6 months following surgery, and yearly thereafter. RESULTS: Mean follow-up was 15.9 months for the SPV and 28.6 months for the Freestyle. Both valves have excellent valve areas and low transvalvar mean gradients. There is a trend for more Al in the SPV group. At 1 year, 1+ or greater Al was present in 11 of 42 SPV patients compared to 2 of 34 Freestyle patients (p = 0.030). Al has tended to remain stable over time, has not progressed, and is not clinically evident. DISCUSSION: Differences in the previously reported incidence of aortic insufficiency with these valves may have more to do with the method of reporting Al than its actual frequency. Within our institution, there has been slightly more mild Al with the SPV valve than with Freestyle. Long-term follow-up of these valves is needed to determine if the Al progresses or becomes clinically important. To date there is no such trend with either valve.