Mitral Valve Replacement Group Research Articles

Durability of the Carpentier-Edwards porcine bioprosthesis: Role of age and valve position

The durability (structural deterioration-free interval) after valve implantation with the first-generation Carpentier-Edwards porcine bioprosthesis has been investigated. From 1978 through 1984, 420 patients (175 male, 245 female) underwent valve replacement with the Carpentier-Edwards standard bioprosthesis. Mean age was 50.6 years (range, 13 to 77 years). Isolated mitral valve replacement (MVR) was performed in 198 patients (47.1%), aortic valve replacement (AVR) in 136 (32.4%), and double valve replacement (DVR) in 86 (20.5%). Hospital mortality was 32 patients (7.6%), 7.5% for MVR, 5.1% for AVR, and 11.6% for DVR. Mean follow-up was 10.8 years (range, 9 to 15 years) and is 96.2% completed. Reoperation for structural deterioration was required in 143 patients. Actuarial curve free from structural deterioration at 15 years is 33.0% +/- 6.5% for MVR, 62.0% +/- 5.1% for AVR, and 44.2% +/- 8.2% for DVR (p < 0.03). Durability of the CE bioprosthesis for MVR was 101.6 +/- 34.5 months, 92.9 +/- 26.4 for AVR, and 84.3 +/- 25.3 for DVR (p = not significant). The regression logistic analysis between age at the time of surgery and durability of the bioprosthesis showed no correlation for the MVR group, but with the following predictive formula for AVR and DVR groups of patients older than 30 years" durability = 46.05 + 0.818 x age, for AVR (r2 = 0.43); durability = 15.81 + 1.122 x age, for DVR (r2 = 0.52). In conclusion, we have found a significant difference in the behavior of the CE porcine bioprosthesis between the mitral and aortic position.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural basis for changes in left ventricular function and geometry because of chronic mitral regurgitation and after correction of volume overload

Left ventricular function and myocyte structure were examined in three groups of dogs: (1) 3 months of mitral regurgitation caused by chordal rupture (n = 7); (2) chronic mitral regurgitation followed by mitral valve replacement and a 3-month recovery period (n = 7), and (3) sham controls (n = 8). The left ventricular end-systolic stiffness constant (Kess) was measured as an index of left ventricular contractile function with stress-strain relationships obtained by cinecatheterization. Isolated myocyte structure and composition were examined with computer-assisted morphometry and nuclear area computed with deoxyribonucleic acid fluorescence. Left ventricular contractile function was significantly depressed with chronic mitral regurgitation compared with control values (Kess, 2.1 +/- 0.1 versus 3.6 +/- 0.2; p < 0.05) and returned to control values with mitral valve replacement (3.8 +/- 0.2). Left ventricular mass significantly increased in both the mitral regurgitation and mitral valve replacement groups compared with control values (121 +/- 10, 120 +/- 5 versus 95 +/- 9 gm, respectively; p < 0.05). Myocyte length increased with mitral regurgitation beyond control values (194 +/- 4 versus 218 +/- 8 microns; p < 0.05) and increased beyond mitral regurgitation values after mitral valve replacement (231 +/- 7 microns; p < 0.05). Myocyte volume with mitral regurgitation increased slightly beyond control values (33.5 +/- 0.7 versus 37.6 +/- 1.3 microns3; p = 0.15) and significantly increased with mitral valve replacement (40.1 +/- 1.2 microns3; p < 0.05). Myocyte myofibril volume significantly declined with mitral regurgitation compared with control values (14.8 +/- 1.5 versus 22.2 +/- 0.7 microns3; p < 0.05) and significantly increased beyond both mitral regurgitation and control values with mitral valve replacement (27.1 +/- 1.1 microns3; p < 0.05). Myocyte nuclear area with mitral regurgitation remained unchanged from control values (1430 +/- 122 versus 1163 +/- 89 microns2) but increased significantly with mitral valve replacement (2209 +/- 250 microns2; p < 0.05). In summary, the left ventricular contractile dysfunction with chronic mitral regurgitation is accompanied by increased myocyte length and reduced myofibril content. In contrast, the left ventricular hypertrophy and improved left ventricular pump function with mitral valve replacement were due to increased myocyte volume and increased contractile protein content.

Low-Dose Anticoagulant Management of Patients with St. Jude Medical Mechanical Valve Prostheses

Between February 1984 and December 1990, 622 St. Jude Medical valves were implanted in 548 patients. There were 382 males (69.7%) and 166 females (30.3%) with a mean age of 32.3 +/- 11.9 years (range 9-68 years). Sixty-eight percent of the patients were referred from rural areas. Three hundred and forty patients underwent aortic valve replacement (AVR), 134 had mitral valve replacement (MVR), and 74 had aortic and mitral valve replacement (DVR). The hospital mortality was 4.7% (16/340) for AVR, 6.7% (9/134) for MVR and 10.8% (8/74) for DVR. Follow-up period ranged from 1.1 to 7.2 years. Total follow-up was 1317.3 patient-years (py). All patients received 2.5 mg warfarin, 225 mg dipyridamole, and 250 mg aspirin daily, regardless of prothrombin time and cardiac rhythm. Thromboembolism was observed in 10 patients (0.75 py); there were 3 mortalities (0.22% py). Valve thrombosis occurred in 4 patients (0.30% py): 3 in the MVR group (0.94% py) and 1 in the AVR group (0.11% py). Hemorrhage occurred in 19 patients (1.44% py) with 11 fatal outcomes (0.83% py). It is concluded that a random daily dose of 2.5 mg warfarin with 225 mg dipyridamole and 250 mg aspirin is sufficient for safe anticoagulation without the need for serial prothrombin-time adjustments.

Clinical experience with the Omnicarbon prosthetic heart valve

The Omnicarbon prosthetic heart valve (Medical Inc., Inver Grove Heights, Minn.) was implanted in 124 patients (mean age 53 +/- 11 years); 66 of them had aortic valve replacement, 40 had mitral valve replacement, and 18 had both aortic and mitral valve replacement. Preoperatively 76.6% were in New York Heart Association class 3 or 4, and 84.7% were in class 1 or 2 after the operation. There were six (4.8%) early deaths and seven late deaths. Survival was 85% +/- 6% at 6 years in the aortic valve replacement group, 94% +/- 4% at 3 years in the mitral valve replacement group, and 78% +/- 11% at 4 years in the double valve replacement group. Freedom from cardiac death was 89% +/- 4% at 6 years (2.0% per patient-year) in the aortic valve replacement group, 94% +/- 4% at 3 years (1.8% per patient-year) in the mitral valve replacement group, and 78% +/- 11% at 4 years (5.7% per patient-year) in the double valve replacement group. There were six valve-related complications. Freedom from valve-related complications was 92% +/- 4% at 6 years (1.5% per patient-year) in the aortic valve replacement group, 97% +/- 3% at 3 years (1.8% per patient-year) in the mitral valve replacement group, and 83% +/- 11% at 4 years (5.7% per patient-year) in the double valve replacement group. Cerebral hemorrhage was seen in two patients in the aortic valve replacement group. Freedom from all events was 80% +/- 7% at 6 years in the aortic valve replacement group, 88% +/- 6% at 3 years in the mitral valve replacement group, and 78% +/- 11% at 4 years in the double valve replacement group. Elevation of the postoperative serum lactate dehydrogenase levels was minimal in all groups. The maximum opening angle at rest was 60.0 +/- 8.9 degrees in the aortic position and 54.1 +/- 6.6 degrees in the mitral position. In conclusion, the Omnicarbon prosthesis had excellent postoperative clinical status and negligible hemolysis.

Use of the Carpentier-Edwards porcine bioprosthesis: Assessment of a patient selection policy

The Carpentier-Edwards bioprosthesis was implanted in 369 patients (414 valves) between May 1977 and December 1987 (age 67.2 +/- 0.5 years); 242 had aortic valve replacement, 80 had mitral valve replacement, 44 had multiple valve replacement, of which 41 were aortic and mitral valve replacement, 2 had isolated tricuspid valve replacement, and 1 had a pulmonary valve replacement. The selection criteria were the following: shorter life expectancy (253 patients) or contraindications to anticoagulants for organic (113 patients) or psychologic (38 patients) reasons, or both. The early mortality rate was 11.1% (aortic valve replacement, 9.1%; mitral valve replacement, 12.4%; aortic and mitral valve replacement, 23.1%). Total cumulative follow-up was 1456 pt-yr (mean 4.4 years, range 1 to 148 months), and the patient evaluation was 99.5% complete. Late mortality was 4.9%/pt-yr. Five-year survival was 70.4% +/- 2.7% overall, 74.3% +/- 3.2% after aortic valve replacement, 60.9% +/- 6.2% after mitral valve replacement (p < 0.03), and 60.7% +/- 8.1% after aortic and mitral valve replacement. Eight patients were reoperated on for primary tissue failure, and freedom from reoperation for structural valve deterioration was 97.5% +/- 1.2% at 5 years and 95.6% +/- 1.8% at 8 years. Failing aortic bioprostheses were explanted in four patients (0.4%/pt-yr) and mitral bioprostheses in seven (1.6%/pt-yr). No patient whose valve was inserted after the age of 70 had to be reoperated on for structural valve dysfunction. The probability of freedom from thromboembolism after 5 and 8 years of follow-up was 93.1% +/- 1.6% and 92.2% +/- 1.8%, respectively. The prevalence of anticoagulant-related hemorrhage was 0.8%/pt-yr (major 0.6%, minor 0.2%). Anticoagulants had to be maintained in 16.3% of the patients: 5.9% after aortic valve replacement, 35.7% after mitral valve replacement, and 45.8% after aortic and mitral valve replacement, while 80.0% were on a regimen of antiplatelet drug therapy. Prosthetic valve endocarditis happened in five patients (0.3%/pt-yr). Freedom from all valve-related morbidity and mortality, including hospital deaths, was 71.0% +/- 2.7% at 5 years and 58.6% +/- 4.6% at 8 years and was significantly better in the aortic valve replacement group (61.3% +/- 6.6% at 8 years) compared with the mitral valve replacement group (54.4% +/- 7.7% at 8 years; p = 0.04). This study confirms the satisfactory performance of the Carpentier-Edwards valve after aortic valve replacement in elderly patients.(ABSTRACT TRUNCATED AT 400 WORDS)

Analysis of left ventricular motion after mitral valve replacement with a technique of preservation of all chordae tendineae

The postoperative regional left ventricular motion of 22 patients with a diagnosis of mitral regurgitation, and who underwent mitral valve replacement with preservation of chordae tendineae, were retrospectively analyzed by cineangiography in the early postoperative period and by multiple-gated cardiac blood pool scintigraphy in the mid-to-late postoperative period. The operation consisted of the division of the anterior leaflet into anterior and posterior segments, the shifting and reattachment of the divided segments to the mitral ring of the respective commissural areas, and the use of a low-profile bileaflet prosthetic valve. Control groups consisted of 28 patients with mitral regurgitation who underwent mitral valve replacement with a conventional technique and 16 patients who underwent mitral valve repair. Compared with the conventional mitral valve replacement group, the radial shortening of the left ventricle of the chordae-preserved mitral valve replacement group was greater at the apical septal, inferoapical, anterobasal, and anterolateral portions, whereas the radial shortening of the repair group was greater than that of the chordae-preserved group only at the inferolateral portion. The ejection fraction of the whole left ventricle was statistically greater in the chordae-preserved group, and also regional ejection fraction of the chordae-preserved mitral valve replacement group was greater at the apical septal, inferoapical, inferolateral, anterobasal, and anterolateral portions than that of the conventional mitral valve replacement group at these portions. On the other hand, the postoperative regional and global motion was identical to that of the mitral valve repair group except at the inferolateral portion. The result of this study supports a concept that maintenance of continuity between the mitral anulus and the papillary muscle has a beneficial effect on postoperative left ventricular performance.

The Atrial Natriuretic Peptide and Its Relation to Hemodynamic and Laboratory Values in Mitral Valve and Coronary Surgery

In 22 patients who underwent mitral valve replacement (13) or coronary bypass surgery (9), preoperative and postoperative plasma atrial natriuretic peptide (p-ANP) concentration, hemodynamic changes, plasma aldosterone, and twenty-four-hour urine sodium-potassium concentrations were studied. Preoperative ANP levels were 261±172 pg/mL in mitral valve replacement (MVR) and 68±22 in coronary artery bypass grafting (CABG); control levels were 15±4.7 (p &lt; 0.001). After the induction of anesthesia, ANP levels decreased to 154.5±96.7 pg/mL in MVR and 51±17.5 in CABG (p &lt; 0.01) patients. In the early postop erative period ANP increased to 332±217 pg/mL in MVR and to 94.3 ± 29.7 in CABG (p &lt; 0.001). In the late postoperative period, the p-ANP of both groups returned to nor mal levels (16 ± 8.05, 11.2 ± 2.82 pg/mL, respectively). Negative correlations were detected in both MVR and CABG groups be tween p-ANP, p-aldosterone (p &lt; 0.001), p—ANP—cardiac output (p &lt; 0.001), and p—ANP—cardiac index (p &lt; 0.001).

Valve-related complications with the Hancock I porcine bioprosthesis: A twelve- to fourteen-year follow-up study

Valve-related morbidity and mortality after heart valve replacement with the Hancock I porcine bioprosthesis has been retrospectively analyzed. From June 1974 through December 1976, 253 Hancock I bioprostheses (150 mitral and 103 aortic) were inserted in 220 selected patients who survived the operation and had follow-up until June 1989 (mean follow-up 13.5 years, with an accumulative follow-up of 2956.4 patient-years). One hundred seventeen patients had mitral valve replacement, 70 had aortic valve replacement, and 33 had combined mitral and aortic valve replacement. There were 27 thromboembolic events. The probability of being free from thromboembolism at 14 years was 81.0% +/- 7.4% for the mitral valve replacement group, 85.4% +/- 6.7% for the aortic group, and 67.1% +/- 18.4% for the mitral-aortic group. Fifteen episodes of prosthetic valve endocarditis occurred. There were 10 instances of nonstructural dysfunction (paravalvular leaks) in seven mitral valves (4.6%) and in three aortic valves (2.9%). One hundred twenty-two bioprostheses in 106 patients resulted in structural deterioration. The probability of freedom from structural deterioration at 14 years was 37.2% +/- 3.9% for the mitral group, 43.9% +/- 7.1% for the aortic group, and 30.1% +/- 8.9% for the mitral-aortic group. The logistic regression analysis between age at the time of operation and bioprosthetic life (structural deterioration-free period) demonstrates a linear regression curve (r = 0.53). There were 56 late deaths (27 patients died at reoperation). The actuarial survival rate (including hospital mortality) at 14 years was 57.2% +/- 5.4% for the entire series, with no statistically significant difference between groups. The probability of remaining free from valve-related morbidity and mortality at 14 years was 16.7% +/- 4.8% for the mitral group, 20.8% +/- 6.2% for the aortic group, and 14.0% +/- 7.0% for the mitral-aortic group. The long-term results of this series show that the clinical performance of the Hancock I porcine valve appears satisfactory during the first 6 years. The behavior of this bioprosthesis at 14 years' follow-up changes drastically, because only a minor group of patients is free from valve-related complications, justifying the restriction of its use for selected patients.

Reoperation for persistant outflow obstruction in hypertrophic cardiomyopathy

This study compares results of a second left ventricular myotomy and myectomy (M + M) with those of mitral valve replacement (MVR) as reoperative procedures for persistent left ventricular outflow obstruction after M + M in hypertrophic cardiomyopathy. Comparison of the second M + M group (n = 12) with the MVR group (n = 11) disclosed significant differences ( p < 0.05) in mean age at the initial operation (29 ± 11 years versus 40 ± 8 years), interval between operations (46 ± 57 months versus 18 ± 13 months), and age at reoperation (33 ± 10 years versus 42 ± 8 years); and insignificant differences in mean preoperative functional class, cardiac index, left ventricular outflow gradients at rest or with provocation, and hospital mortality at reoperation ( 2 / 12 versus 1 / 11 ). At 6 months after reoperation, comparison of results of a second M + M with MVR showed that mean functional class, cardiac index, and left ventricular outflow gradient at rest were similarly improved, but the outflow gradient with provocation was significantly higher in the second M + M group (57 ± 44 mm Hg versus 14 ± 9 mm Hg, p < 0.05). Total follow-up was 108 patient-years (100% complete) with an average of 5.9 years per patient in the second M + M group and 3.4 years per patient in the MVR group. Actuarial survival, including hospital mortality, at 3 and 5 years was 83% and 76%, respectively, after the second M + M, which was similar to 92% and 77% after MVR. Thus, either a second M + M or MVR is effective in relieving the hemodynamic obstruction and decreasing symptoms, but a second M − M is preferable because complications of anticoagulation and substitute valves are avoided.

Comparative study between valve repair and replacement for mitral pure regurgitation. Early and late postoperative results.

From May 1975 through December 1988, 91 patients (mean age 50.4 +/- 12.8 years) had first-time surgery for mitral pure regurgitation; 48 had mitral valve replacement (MVR) and 43 had valve repair. A majority of the patients had non-rheumatic valvular diseases. Those patients who underwent repair had less hemodynamic and functional derangement than those who underwent MVR. The operative mortality was 8.3% in the MVR group and 2.3% in the repair group. Seventeen percent of the MVR group and 2% of the repair group required intra-aortic balloon pumping support (p less than 0.03). A higher dose of dopamine and/or dobutamine during the early postoperative period was necessary in the MVR group (7.0 +/- 4.8 micrograms/kg/min) than in the repair group (5.1 +/- 3.1 micrograms/kg/min). Duration of respirator support for hospital survivors was longer in the MVR group (2.3 +/- 2.7 days) than in the repair group (1.4 +/- 1.0 days). There were 5 late deaths (2.2 +/- 1.0%/pt-yr) not counting 6 non-cardiac deaths in the MVR group and 1 (0.6 +/- 0.6%/pt-yr) in the repair group. There were 17 patients (7.5 +/- 1.8%/pt-yr) who experienced treatment failure in the MVR group and 5 (2.3 +/- 1.3%/pt-yr) in the repair group (p less than 0.02). Eight patients in the MVR group (3.5 +/- 1.3%/pt-yr) underwent repeat surgery in the late postoperative period, as did 3 (1.7 +/- 1.0%/pt-yr) in the repair group. There was no increase in the incidence of repeat surgery after valve repair. All the current survivors in the repair group, and 96% of those in the MVR group were in NYHA functional class I or II. These results indicate that mitral repair is the preferred operative procedure for pure mitral regurgitation, whenever it is possible.

Thromboembolism in patients with pericardial valves in the absence of chronic anticoagulation: 12 years' experience

Between January 1977 and January 1989, 465 pericardial bioprostheses were implanted in 424 patients. The mean age of patients was 59.1 years (range 16-81 y.) At the time of surgery, 68% of the patients suffered from chronic atrial fibrillation. Mitral valve replacement was performed in 167 patients, aortic valve replacement in 216, multiple replacement in 40 (36 mitral and aortic, 3 mitral and tricuspid, and 1 mitral, aortic and tricuspid), and 1 pulmonary valve replacement. The different types of pericardial valve used were: Ionescu-Shiley 408, Mitral Medical 23, Bioflo 30, and Hancock 4. Hospital mortality was 10.1% with an attrition rate of 1.8 episodes per 100 patients/year. The 12-year actuarial survival rate was 65.1%. No patient underwent long-term anticoagulant treatment. The first 144 patients undergoing mitral and multiple valve replacements received temporary anticoagulation for the first 8 weeks after surgery. There was no valve thrombosis observed. Altogether 19 thromboembolic events (6 early and 13 late) were clinically documented. One patient died after an embolic event. The linearized rates of thromboembolism were 1.64 episodes per 100 patients/year for mitral and multiple valve replacements and 0.33 episodes per 100 patients/year for aortic valve replacement, with an overall rate of 1.0 episodes per 100 patients/year. Excluding early thromboembolism, the linearized rate was 1.02 episodes per 100 patients/year overall. The actuarial freedom from embolism was 92.4% overall, 88.2% for the mitral and multiple valve replacement group, and 97.6% for the aortic valve replacement group at a maximum follow-up of 12 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Ten-year experience with the porcine bioprosthetic valve: Interrelationship of valve survival and patient survival in 1,050 valve replacements

The porcine bioprosthetic valve was used in 440 patients having isolated mitral valve replacement (MVR), 522 patients having isolated aortic valve replacement (AVR), and 88 patients having MVR + AVR between 1974 and 1981. Patients with associated surgical procedures were excluded. Mean follow-up was 8.3 year. At 10 years, there was no difference in patient survival between those having AVR and these having MVR. Reoperations were performed on 192 patients. Endocarditis was the reason for operation in 3.7% of patients who had MVR and 10.6% of those who had AVR. Structural valve degeneration was the reason for reoperation in 89.7% of MVR patients and 78.8% of AVR patients ( p = 0.04). Hospital mortality among patients having valve reoperations was 4.7%. At 10 years, the freedom from valve reoperation for all causes and from structural valve degeneration was significantly better for the AVR group than the MVR group (74% ± 3% versus 61% ± 4%, p = 0.004; and 79% ± 3% versus 63% ± 4%, p = 0.0006, respectively). For patients in their 60s, the 10-year freedom from reoperation was 92% ± 2% for AVR and 80% ± 6% for MVR ( p = not significant). At 10 year, freedom from cardiac-related death and valve reoperation was best for both MVR and AVR patients in their 60s. Patients 70 years old or older rarely had reoperation but died before valve failure occurred. The 10-year freedom from all major valve-related events (cardiac-related death, reoperation, thromboembolism, endocarditis, and anticoagulant-related bleeding) was practically the same for both MVR and AVR patients (48% ± 3% versus 49% ± 3%, respectively). The porcine bioprosthetic valve is the valve of choice only for patients 60 year old or older. Patients in their 70s have an extremely low rate of reoperation but a high rate of cardiac-related death and do not outlive the prostheses.

Valve replacement in the elderly: Is the mechanical valve a good alternative?

The controversy surrounding the choice of a prosthesis for valve replacement in the elderly patient prompted me to review the performance of mechanical (Medtronic Hall [Medtronic, Inc., Minneapolis, Minn.] and St. Jude Medical [St. Jude Medical, Inc., St. Paul, Minn.]) valves implanted in 213 patients 65 years and older (mean 70.4 years) from 1980 to 1985. There were 63 mitral, 131 aortic, and 19 double (aortic and mitral) valve replacements. Most patients undergoing aortic valve replacement had stenotic lesions, but half of the patients in the mitral valve replacement group had regurgitation with or without stenosis. Early mortality rates for mitral, aortic, and double valve replacement were 4.8%, 6.1%, and 21.1%, respectively (p less than 0.01). The mortality rate for patients 65 to 74 years old was 6.5% and that for those older than 75 years was 9.1%. The cumulative follow-up for the survivors was 850 patient-years. The late mortality rate was 8.1% per patient-year but was valve-related in only 1.3% per patient-year. Noncardiac causes accounted for 43.5% of the late deaths. The late mortality rate was significantly higher in patients who had regurgitant lesions than in those who had stenotic or mixed disease. It was also higher in the older patients (10.3% per patient-year) than in the younger group (7.6% per patient-year; p less than 0.05). Reoperation was required in only six patients (0.7% per patient-year). Thrombotic obstruction of the prosthesis and systemic thromboembolism occurred at linearized rates of 0.6% per patient-year and 2.5% per patient year, respectively, and significant anticoagulant-related hemorrhage at a rate of 0.6% per patient-year. With the exception of late mortality, the incidence of all late complications was similar to that of patients younger than 65 years operated on during the same period. Actuarially, global survival (58% +/- 4%) and freedom from reoperation (95% +/- 2%), from thrombotic obstruction (96% +/- 1%), from thromboembolism (92% +/- 2%), from all valve-related mortality and morbidity (82% +/- 3%), and from valve failure (93% +/- 2%) were also similar to those of the younger patients. Mechanical prostheses perform well in elderly patients. I could not confirm an increase in thromboembolic or hemorrhagic episodes, and the respective mortality and morbidity indexes were similar to those observed in younger patients.

Evaluation of the left ventricular reserve by dynamic exercise echocardiography after surgery for valvular heart diseases.

Dynamic ergometer exercise in a supine position was applied to 64 patients more than 1 year after valvular heart surgery, and the left ventricular reserve was evaluated echocardiographically. The left ventricular reserve declined in the mitral stenosis-mitral valve replacement group, while it was better maintained in the mitral stenosis-mitral commissurotomy, aortic regurgitation and aortic stenosis groups. The patients were divided into 3 groups depending on whether the percentage increase during exercise of stroke index, an index of left ventricular pump function, increased, unchanged, or decreased. The percentage increase of mean velocity of circumferential fibre shortening (y) and that of left ventricular end-diastolic diameter (x) during exercise were plotted for each group. The increased group was isolated from the unchanged group by the line of y = -5.02x + 30.1; the unchanged group was isolated from the decreased group by that of y = -5.68x-10.0, and the increased and unchanged groups were clearly isolated from the decreased group by that of y = -6.86x-4.76. We conclude that dynamic ergometer exercise echocardiography is useful for evaluating the left ventricular reserve of postoperative patients with valvular heart disease. It was also thought that the subclinical state of cardiac failure can be effectively detected by the present method.

Mechanical valve replacement in children and teenagers.

A previous study from this unit showed that only 19% of children with mitral bioprostheses were free from complications after 7 years and prompted us to review the performance of new-generation mechanical prostheses implanted in the same population group. In a 5-year period (1980-1985), 352 patients 20 years old and younger (mean age 15.3 +/- 4 years) with rheumatic valvular disease had 177 mitral, 62 aortic and 113 double (mitral + aortic) valve replacements with Medtronic-Hall or St. Jude prostheses. The overall early mortality was 6.3%. All survivors, followed up for a total of 1171 patient-years, received oral anticoagulation. The late mortality for mitral, aortic and double valve replacement was 4.1% per patient-year, 4.3% per patient-year and 8.0% per patient-year, respectively (P less than 0.05), and was valve-related in 46% of the cases. Twenty-nine patients, all but 2 in the mitral and double valve replacement groups, were reoperated upon (2.5% per patient-year), mainly for infective endocarditis (34%), for prosthetic thrombosis (33%) and for bland periprosthetic leak (31%). The incidence of thrombotic obstruction was 1.1% per patient-year: mitral valve replacement, 1.0% per patient-year; aortic valve replacement 0.5% per patient-year; and double valve replacement, 1.7% per patient-year; P less than 0.05) and was fatal in 33% of the cases. Major systemic thromboembolism occurred at the rate of 1.4% per patient-year, similar in the three groups. The incidence of prosthetic endocarditis was 0.9% per patient-year.(ABSTRACT TRUNCATED AT 250 WORDS)

Left atrial spontaneous echo contrast in mitral valve disease: An indicator for an increased thromboembolic risk

The incidence of left atrial spontaneous echo contrast was evaluated in 52 patients with isolated or predominant mitral valve stenosis (Group 1) and 70 other patients who had undergone mitral valve replacement (Group 2). All patients were studied by conventional transthoracic and transesophageal two-dimensional echocardiography. Spontaneous echo contrast could be visualized within the left atrium in 35 Group 1 patients (67.3%) (including 7 patients with sinus rhythm) and 26 Group 2 patients (37.1%) (all with atrial fibrillation).Patients with spontaneous echo contrast had a significantly larger left atrial diameter and a greater incidence of both left atrial thrombi and a history of arterial embolic episodes than did patients without spontaneous echo contrast. Association between spontaneous echo contrast and left atrial thrombi and a history of arterial embolization (considered individually or in combination) showed a high sensitivity and negative predictive value. It is concluded that spontaneous echo contrast is a helpful finding for identification of an increased thromboembolic risk in patients with mitral stenosis and after mitral valve replacement.

St. Jude Medical Prosthesis: Valve-Related Deaths and Complications

Despite the hemodynamic improvement in cardiac valve prostheses, valve-related deaths and complications have remained a substantial source of morbidity and mortality. This follow-up study was carried out in April, 1986, in a group of 816 patients who received 876 St. Jude Medical prostheses between October, 1977, and October, 1984. One hundred fifty-five patients (37%) of the 422 having aortic valve replacement (AVR) and 88 (29%) of the 300 having mitral valve replacement (MVR) had concomitant coronary artery bypass grafting, and 94 patients (12%) had miscellaneous procedures performed in addition to valve replacement. Sixty-three patients died within the operative period, an operative mortality of 7.7%. Follow-up was complete for 98% of the patients; the mean follow-up was 42 months. At that time, 87 more patients had died, a late mortality of 11.9%. There were 13 valve-related deaths (4 in the AVR group, 7 in the MVR group, and 2 in the miscellaneous group); the causes of death were thromboembolism (7), anticoagulant-related hemorrhage (2), valve thrombosis (2), prosthetic valve endocarditis (1), and perivalvular leak (1). There were 37 thromboembolic episodes (1.78/100 patient-years) and 67 anticoagulant-related hemorrhages (3.22/100 patient-years), 46% of which necessitated transfusion. The incidence of valve thrombosis was 0.6% (4 patients). Perivalvular leak and prosthetic valve endocarditis occurred in 7 patients (1.0%) and 5 patients (0.7%), respectively. Reoperation was carried out in 6 patients (0.8%), but only for perivalvular leak. There were no deaths, no complications, and no clinical evidence of malfunction of the prosthetic valve. The incidence of perivalvular leak, prosthetic valve endocarditis, and reoperation was rather low, and severe hemolysis occurred only in association with perivalvular leak. Thromboembolic phenomena and anticoagulant-related hemorrhage, however, have remained our major concern in spite of the favorable 7-year survival.

Clinical, hemodynamic, and angiographic predictors of operative mortality in patients undergoing single valve replacement

Preoperative characteristics of 964 patients in the Veterans Administration Cooperative Study on Valvular Heart Disease undergoing single valve replacement were examined to determine predictors of operative mortality. The operative mortality rate was 8.3% in 661 patients having isolated aortic valve disease and 7.5% in 239 patients having isolated mitral valve disease, but 12.5% in 64 patients with multivalve disease undergoing single valve replacement. For the aortic valve replacement subgroup, three-vessel coronary artery disease, left ventricular systolic pressure, prior cardiac operation, body surface area, and cardiac index were related to operative mortality. In the mitral valve replacement group, there was a strong association of operative mortality with advanced age, exertional dizziness, reduced cardiac index, left ventricular contraction grade, ST segment depression on the resting electrocardiogram, and pleural effusion. The risk of operative death for an individual patient undergoing aortic or mitral valve replacement may be estimated with the use of independent risk factors.

Durability and Low Thrombogenicity of the St. Jude Medical Valve at 5-Year Follow-up

Between November, 1978, and December, 1983, 736 patients had valve replacement with the St. Jude Medical valve prosthesis. There were 478 patients with aortic valve replacement (AVR), 188 with mitral valve replacement (MVR), 63 with double valve replacement, and 7 with tricuspid valve replacement (they were not included in this study). The mean age at the time of operation was 46.7 years for patients having AVR and 48.6 years for those having MVR and AVR + MVR. Follow-up totaled 1,116 patient-years (range, 4 to 82 months). Early (30-day) mortality was lowest for isolated MVR (2.3%) and AVR (3.7%), and increased with reoperation or when associated procedures were combined with valve replacement. Patients undergoing reoperation or having associated procedures made up 49% of the AVR and 54% of the MVR groups. All patients were advised of the need for long-term anticoagulation with warfarin sodium. Nine patients (7 with AVR, 1 with MVR, 1 with AVR + MVR) had suspected or confirmed episodes of systemic thromboembolism, a linearized incidence of 0.99% per patient-year for AVR, 0.36% per patient-year for MVR, and 0.98% per patient-year for AVR + MVR. Eight patients with AVR underwent reoperation for prosthetic valve endocarditis (5 of the 8 patients had endocarditis prior to initial valve replacement). There were no instances of structural valve failure. There were 37 late deaths. Actuarial survival at 5 years (excluding early mortality, 95% confidence limits) was 89.8% for AVR, 84.8% for MVR, and 95.2% for AVR + MVR. At 5-year follow-up the St. Jude Medical prosthetic valve has a low incidence of valve-related complications, which makes it a suitable choice in patients requiring valve replacement.

Changes in serum creatine kinase and lactate dehydrogenase caused by acute perioperative myocardial infarction and by transatrial cardiac surgical procedures

A prospective clinical study was conducted to ascertain if a patient's postoperative elevation in serum creatine kinase MB isoenzyme coupled with determination of the lactate dehydrogenase1/lactate dehydrogenase2 ratio could differentiate whether atrial or ventricular myocardium was the source of these changes. Animal studies have shown that atrial myocardium is as rich a source of creatine kinase MB as is ventricular myocardium. Atrial myocardium has a lactate dehydrogenase1/lactate dehydrogenase2 ratio less than 1.00, whereas in ventricular myocardium the ratio is greater than 1.00. Sixty-four patients were assigned to six groups on the basis of serial electrocardiograms and vectorcardiograms by a cardiologist who was unaware of their clinical courses. The control group (Group 1) consisted of 16 patients admitted to the coronary care unit who had no electrocardiographic changes. Three surgical groups without electrocardiographic or vectorcardiographic evidence of perioperative myocardial infarction were studied: 10 patients undergoing routine coronary artery bypass procedures (Group 2), six adults undergoing repair of secundum atrial septal defect (Group 3), and 13 patients having mitral valve replacement (Group 4). Two groups of surgical patients who had acute perioperative transmural myocardial infarctions confirmed by serial electrocardiograms and vectorcardiograms were studied: 15 patients (Group 5) who had elective coronary artery bypass procedures and four (Group 6) who had mitral valve replacement. This study suggests that serum creatine kinase MB levels in excess of 50 IU/L on the postoperative day 1 and day 2 samples coupled with serum lactate dehydrogenase1/lactate dehydrogenase2 ratios greater than 1.00 on the postoperative day 2 and day 3 samples support the diagnosis of acute myocardial infarction. Patient groups undergoing procedures necessitating atriotomies had average elevations in serum creatine kinase MB and in the lactate dehydrogenase1/lactate dehydrogenase2 ratio, but these were significantly less than those seen when acute perioperative myocardial infarction had occurred.