Cavitation has recently entered the discussion of factors leading to blood and material damage after implantation of mechanical heart valves. Since direct evidence for this phenomenon cannot yet be demonstrated in vivo, an in vitro method had to be developed to permit the investigation whether cavitation actually occurs under (simulated) physiologic conditions and to clarify its clinical relevance. Previous studies have shown that different types of commercially available mechanical valves exhibit different tendencies to generate cavitation in vitro. The present study presents a test protocol for the assessment of cavitation generated by different replacement valves under simulated physiologic conditions. Comparative investigations were performed in order to transfer the in vitro results in vivo conditions. Although mechanical valves with an overlapping closing body/valve ring configuration tend to create cavitation earlier, cavitation could not be demonstrated for any investigated mechanical valve type under simulated resting conditions. The danger of continuous cavitation damage is therefore low. Certain valve types exhibit cavitation only at higher heart rates (more than 120-140 beats/min). Some valve types do not show cavitation even during heavy exercise. Based on mathematical models and experimental investigations, it is very likely that if cavitation does occur, blood and material damage may be expected.

How to cite: Graf, T., Reul, H., Dietz, W., Wilmes, R., & Rau, G. (1992). Cavitation of mechanical heart valves under physiologic conditions. The Journal of heart valve disease, 1(1), 131–141.

The lifetime of bioprosthetic heart valves is limited by primary tissue failure and calcification of the valve leaflets. There are indications that synthetic elastomeric materials may also be subject to this problem. The mechanism of calcification is not known, but it is of interest that calcification can be induced in tissue even in the absence of cellular mechanisms, outside the body. Many hypotheses relate to inhibitory or promotory factors rather than primary instigators of calcification and none has led to a satisfactory solution of the problem. The study of calcification in replacement valves generally utilises in vivo test methods i.e. complex biologic systems. This creates difficulty in defining the primary factors involved. The use of in vitro test methods, including a novel fatigue tester method, has been reviewed. Various test media have been used, including simple salt solutions (allowing definition and controlled modification of the calcification medium) and bovine plasma. Comparison of static and dynamic in vitro methods with the rat subcutaneous implant model indicated a lower degree of calcification in vitro: the calcification achieved was, however, significantly greater than similar material not subject to calcification processes. Dynamic in vitro tests produced greater calcification than static in vitro tests. Porcine aortic valve material, in static tests, behaved similarly to bovine pericardium. In vitro calcification testing has a useful role to play in the economic screening of new materials or modifications of existing materials prior to in vivo testing. It may also aid the definition of the mechanism of calcification and hence the development of solutions to the problem.

How to cite: Bernacca, G. M., Mackay, T. G., & Wheatley, D. J. (1992). In vitro calcification of bioprosthetic heart valves: report of a novel method and review of the biochemical factors involved. The Journal of heart valve disease, 1(1), 115–130.

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How to cite: Schoen, F. J., Golomb, G., & Levy, R. J. (1992). Calcification of bioprosthetic heart valves: a perspective on models. The Journal of heart valve disease, 1(1), 110–114.

Mycobacterial infection is an uncommon but very serious complication of heart valve replacement and other forms of cardiac surgery. Tuberculosis has been a rare complication of valve replacement in the industrially developed countries owing to the low incidence of that disease in such countries. Most reported cases are associated with the insertion of human allograft valves. Valvular tuberculosis could become a more serious problem if heart valve replacement surgery is used to any extent in countries where tuberculosis is common. The majority of other mycobacterial infections occurring after heart surgery have, for unknown reasons, been due to the rapid growers M. chelonae and M. fortuitum. Porcine xenograft valves have been contaminated by M. chelonae, possibly during manufacture as this is not a natural pathogen of pigs. A minority of patients receiving valves known to be contaminated by M. chelonae subsequently developed valve disease. Mycobacterial disease following insertion of mechanical valves is a very uncommon occurrence but the prognosis is poor. There have been several outbreaks of infection of the sternotomy wound by M. chelonae and M. fortuitum and, although the prognosis is better than for mycobacterial endocarditis, treatment, especially for infections due to M. chelonae, often involves extensive debridement including removal of the entire sternum. In view of the poor response to therapy, prevention by avoidance of contamination of all surgical materials, including implanted valves, by environmental mycobacteria is of paramount importance.

How to cite: Grange J. M. (1992). Mycobacterial infections following heart valve replacement. The Journal of heart valve disease, 1(1), 102–109.

Rheumatic heart disease contributes to significant cardiac morbidity and mortality in India. The disease predominantly affects the valvular endocardium culminating in crippling valvular deformities, preferentially involving the mitral valve which may be severely affected in children and young adults. This appears to be unique to India and has been termed juvenile mitral stenosis. It is characterized by cardiomegaly, refractory congestive heart failure, and marked by elevated pulmonary vascular pressures and a progressive, fulminant clinical course. Autopsies of patients dying of rheumatic heart disease revealed that the mitral valve was most commonly afflicted either alone or in combination with the aortic and tricuspid valves in 31.6% and 52.8%, respectively. Organic involvement of the tricuspid valve was documented in 38.4% of cases. The extent and severity of the disease process was most marked in the mitral valve, followed by the aortic and tricuspid valves. Mitral valves showed various degrees of calcification, moderate or severe calcification being observed in 36.4%. Chronic inflammatory cell infiltration was observed in both calcified and non-calcified valves. The phenotypic profile of the inflammatory cells by immunohistochemical staining revealed a significant number to be T-helper/inducer lymphocytes. Lungs from cases of mitral stenosis exhibited prominent vascular and parenchymal changes. Pulmonary vessels revealed moderate to marked medial hypertrophy of the medium sized branches of the pulmonary artery. Dilatation lesions were also seen in a few cases. The most striking parenchymal change was the prominent smooth muscle in the bronchoalveolar walls. The extent and severity of the vascular and parenchymal changes were more marked in juvenile patients. The presence of inflammatory cells in cases of chronic heart disease reflects a possible ongoing insult/injury to some persistent antigenic stimulus by beta hemolytic streptococcal antigens that have primed the various target tissues. Further study of surface characteristics of various mesenchymal cells may help in understanding the nature and pathogenesis of this serious cardiac problem.

How to cite: Chopra, P., & Bhatia, M. L. (1992). Chronic rheumatic heart disease in India: a reappraisal of pathologic changes. The Journal of heart valve disease, 1(1), 92–101.

From 1975 to 1989, over 1400 patients in the elderly population and over 1700 patients under 65 years of age received the Carpentier-Edwards standard (CE-Standard) and supra-annular porcine (CE-SAV) bioprotheses. The mean ages of the patients receiving the two protheses within the three subgroups of the elderly population-65-69 years, 70-79 years, and 80 years and over-were relatively similar. There was no statistically significant difference in the performance of the prostheses regarding structural valve deterioration (SVD) at seven years. The freedom from SVD for aortic valve replacement in the 65-69 years group at seven years was 98.7% +/- 1.3% for the CE-Standard and 98.7% +/- 1.0% for the CE-SAV, for both the 70-79 years group and the 80 years and over group the figure was 100% for both prostheses (p = NS). The freedom from SVD after mitral valve replacement in the 65-69 years group at seven years was 90.0% +/- 4.3% for the CE-Standard and 84.8% +/- 7.5% for the CE-SAV, for the 70-79 years group it was 95.3% +/- 3.2% and 95.5% +/- 3.6% respectively and for the 80 years and over group the figure was 100% for both prostheses (p = NS within groups). The long term freedom from SVD after aortic valve replacement was 98.4% +/- 3% at 15 years for the CE-Standard in the 65-69 years group, 94.9% +/- 5% at 13 years for the 70-79 years group and 100% at 13 years for the 80 years and over group.(ABSTRACT TRUNCATED AT 250 WORDS)

How to cite: Burr, L. H., Jamieson, W. R., Munro, A. I., Miyagishima, R. T., Janusz, M. T., Ling, H., Hayden, R. I., Tutassaura, H., Fradet, G., & Gudas, V. M. (1992). Structural valve deterioration in elderly patient populations with the Carpentier-Edwards standard and supra-annular porcine bioprostheses: a comparative study. The Journal of heart valve disease, 1(1), 87–91.

The development of late tricuspid regurgitation is an important complication of mitral valve surgery, as it is associated with a severe impairment of exercise capacity and a poor symptomatic outcome. The pathogenesis of this condition remains poorly defined, but it is usually attributable to a functional abnormality of the tricuspid valve. Whilst its development may indicate an increased afterload on the right heart as a consequence of persistent pulmonary hypertension, mitral prosthetic dysfunction, progressive aortic valve disease or left ventricular failure, late tricuspid regurgitation may also develop in the absence of these factors and then may reflect right ventricular dysfunction and/or a localized abnormality of the tricuspid anulus. Failure to recognize and correct tricuspid regurgitation at the time of initial surgery may also account for many cases of tricuspid regurgitation but its re-appearance following tricuspid annuloplasty is uncommon and usually reflects a failure of the mitral prosthesis. A reduction in the prevalence of late tricuspid regurgitation is an important objective in view of the high operative mortality and disappointing long term results associated with reoperation for tricuspid regurgitation. This may be best achieved through combining earlier mitral valve surgery with the accurate detection and liberal correction of accompanying tricuspid incompetence at the time of initial surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

How to cite: Groves, P. H., & Hall, R. J. (1992). Late tricuspid regurgitation following mitral valve surgery. The Journal of heart valve disease, 1(1), 80–86.

In order to evaluate the incidence and prognostic value of ventricular arrhythmias in patients with aortic valve disease, 24 hour ambulatory electrocardiographic recordings were obtained in 374 patients without coronary artery disease (aortic stenosis n = 194, aortic regurgitation n = 103, combined aortic stenosis and regurgitation n = 77). Following aortic valve replacement, repeat recordings were obtained in a subgroup of 96 patients at 13 +/- 4 days and 18 +/- 7 months. Ventricular arrhythmias were classified in all cases according to Lown and were compared with clinical, echocardiographic and hemodynamic data. Preoperatively, ventricular premature beats were observed in 329 patients (88%), and were found to be frequent (>30 ventricular premature beats/hour) in 83 (22%). Multiformity was found in 105 (28%), couplets in 75 (20%) and ventricular tachycardia in 45 (12%). The occurrence of ventricular arrhythmias was not related to the type or severity of the valve lesions. Patients with severe ventricular arrhythmias (Lown class 3 or 4: 36.5%) had a higher ventricular wall thickness (interventricular septum thickness 14.2 +/- 1.8 mm vs. 11.9 +/- 2.0 mm, p < 0.01, a higher LV mass (178 +/- 32 g/m2 vs. 142 +/- 35 g/m2, p < 0.001) and a lower left ventricular ejection fraction (48% +/- 9% vs. 56.5% +/- 10%, p < 0.001); while in patients with aortic regurgitation a higher end-diastolic LV volume (224 +/- 38 ml/m2 vs. 178 +/- 42 ml/m2, p < 0.02) and a higher end-systolic LV diameter (56 +/- 7 mm vs. 46 +/- 8 mm, p < 0.02) were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

How to cite: Michel, P. L., Mandagout, O., Vahanian, A., Cormier, B., Iung, B., Luxereau, P., & Acar, J. (1992). Ventricular arrhythmias in aortic valve disease before and after surgery. The Journal of heart valve disease, 1(1), 72–79.

To evaluate the acute change in the mitral flow pattern, especially pressure half-time after percutaneous transvenous mitral commissurotomy (PTMC) and to investigate the factors influencing the mitral flow pattern, Doppler and two-dimensional echocardiographic studies were performed in 15 patients before and two, six, 10 and 24 hours and seven days after PTMC. Mitral valve area increased and the mean mitral pressure gradient decreased after PTMC (1.0 +/- 0.4 cm2 to 1.8 +/- 0.4 cm2; 11 +/- 6 mmHg, to 3 +/- 2 mmHg, p < 0.01). Pressure half-time also decreased two hours after surgery, from 292 +/- 70 msec to 176 +/- 48 msec (p < 0.01) and then gradually decreased to 140 +/- 47 msec within seven days of the procedure without remarkable changes in mitral valve area and the mean transmitral pressure gradient. Left atrial dimensions decreased and left ventricular end-diastolic dimensions gradually increased after PTMC (51 +/- 6 mm to 46 +/- 5 mm; 47 +/- 4 mm to 50 +/- 3 mm). The time course of this was similar to that of the pressure half-time. Further study, in which the changes in pressure half-time were evaluated within 30 minutes of PTMC in 17 patients, indicated that pressure half-time significantly decreased from 248 +/- 69 msec to 139 +/- 28 msec five minutes after balloon inflation, slightly increasing again after 30 minutes to 153 +/- 31 msec.(ABSTRACT TRUNCATED AT 250 WORDS)

How to cite: Ishikura, F., Nagata, S., Tamura, T., Fujiwara, H., Yasuda, S., Nakatani, S., Beppu, S., & Miyatake, K. (1992). Serial changes of mitral flow pattern after percutaneous transvenous mitral commissurotomy--assessment of Doppler and two-dimensional echocardiography. The Journal of heart valve disease, 1(1), 65–71.

Balloon aortic valvuloplasty results in small changes in valve area with great symptomatic improvement in some patients, while others have little relief with greater increases in valve area. Alternative indices to valve area may help explain this clinical discrepancy. A calculation of valve area does not provide a means of assessing the load imposed by a stenotic valve, while the complementary index valve resistance, defined as the quotient of mean pressure difference divided by flow, allows many other hemodynamic calculations and may provide an additional measure of the hemodynamic importance of valvular obstructions. To assess the value of these calculations, we studied hemodynamic changes in thirty elderly patients undergoing valvuloplasty for aortic stenosis. The valve area, as calculated by the Gorlin formula, increased by an average 67% (0.59 cm2 to 0.95 cm2), while hemodynamic resistance decreased by an average 52% (453 to 207 dyne.sec.cm5). The values of resistance were used to predict pressure gradients and work loads at different cardiac outputs. The increase in myocardial reserve with valvuloplasty was calculated as the increase in cardiac output that could be achieved at the pre-valvuloplasty value of either total ventricular pressure or ventricular work. These calculations assumed that valvular resistance did not change with cardiac output and that peripheral resistance varied inversely to cardiac output so as to maintain a constant aortic (systemic) pressure. The increase in myocardial reserve was 18% when ventricular work rate was the limiting factor, and 103% when pressure was limiting. The increase in reserve may be closer to the higher value since the myocardial work rate is probably not limited by myocardial energy in the absence of coronary artery disease. Four patients who did not do well clinically were characterized by small increases in reserve, either because of inadequate dilatation of the valve or because the original stenosis was not severe. Valve resistance, myocardial reserve, and ventricular work may be calculated using standard hemodynamic measurements. In conjunction with aortic valve area, these indices provide significant complimentary information and may further elucidate the hemodynamic consequences of valvular obstruction.

How to cite: Feldman, T., Ford, L. E., Chiu, Y. C., & Carroll, J. D. (1992). Changes in valvular resistance, power dissipation and myocardial reserve with aortic valvuloplasty. The Journal of heart valve disease, 1(1), 55–64.

Late outcome vs. hemodynamic parameters were assessed and compared in a series of 44 patients followed for 10-17 years after aortic valve replacement either with a Starr-Edwards A 1260 (SE) or a Bjork-Shiley 60 degrees (BS) prosthesis. The two groups, 22 patients each, were selected by computer from the data base SG as to be matched for age, sex, underlying lesion, date of implantation, valve size, left ventricular function, and concomitant coronary artery disease. There was no significant difference in mortality and complication rates. Clinical evaluation at a mean of 12.5 +/- 2.2 years postoperatively revealed identical findings of heart size on chest X-rays (CTR 0.50 +/- 0.04 SE vs. 0.50 +/- 0.05 BS) and nearly identical incidence of left ventricular hypertrophy on the ECG (2/22 SE and 1/22 BS). There was a statistically significant difference in Doppler ultrasonic peak pressure gradients between the two valve types (SE 32 +/- 15 mmHg, BS 23 +/- 9 mmHg; p = 0.047), and of fractional shortening on M-mode echocardiograms (SE 30 +/- 9%, BS 37 +/- 8%, p = 0.038), but this was not reflected by a difference in the symptomatic status of the two groups. It is concluded, that in two groups of patients surviving 10-17 years after isolated aortic valve replacement with SE or BS valves, the statistically significant nine mmHg difference in gradient across the two valve types had no effect on long-term clinical outcome.

How to cite: Hoffmann, A., Haefeli, R., Weiss, P., Stultz, P., Peter, M., Gradel, E., & Burckhardt, D. (1992). Influence of different pressure gradients on late clinical outcome after aortic valve replacement. The Journal of heart valve disease, 1(1), 51–54.

Recent efforts at reducing health care expenditures and practice variations have focused attention on treatment appropriateness, patient preference, and quality of life as important elements of treatment evaluation. These characteristics of medical treatment can be assessed by administration of a structured, valid health status assessment questionnaire before and at fixed intervals following treatment, and standardized scores may be compared to normal scores derived from healthy, untreated populations. One hundred valve replacement patients completed a standardized questionnaire, the 'SF-36', preoperatively and at 1- and 6-months postoperatively. Preoperatively, valve replacement patients are substantially impaired in their physical capacity, their ability to function in important roles, and their vitality. At one month, they report significant decrements in social and role functioning and in pain which we attribute to the trauma of surgery and recovery. At six months, mean scores approximate those for sex- and age-matched normals except for persistent moderate impairment in role functioning. Post-operative functional impairment is greatest for those undergoing mitral valve replacement, particularly when coronary artery grafts are performed concurrently, and for patients receiving bioprosthetic valves. Structured health status assessment provides a useful adjunct to other methods of assessing clinical status and evaluating treatment outcomes.

How tp cite: Phillips, R. C., & Lansky, D. J. (1992). Outcomes management in heart valve replacement surgery: early experience. The Journal of heart valve disease, 1(1), 42–50.

Over the last three decades, heart valve replacement has become a safe and routine surgical procedure, but replacement devices are still far from ideal. Despite improvements in materials and design, life-long anticoagulation remains mandatory for mechanical valves. The major shortcoming of the less thrombogenic bioprosthetic valves is early tissue failure. Parallel to the decrease in operative mortality after heart valve replacement, the potential quality of life for survivors has been becoming increasingly important in evaluating the late results and in selecting the appropriate device for the given patient. All factors that determine the quality of life are strongly affected by the operation due to the usually dramatic improvement both in subjective status and objective parameters postoperatively. The patient, thus, can return to normal activities, maintain self-esteem and keep normal relationships at work, in the community and at home. Psychoneurologic dysfunction was also found to decrease greatly within six months, although more than a quarter of patients were depressed preoperatively because of their disease. Overall, the experience was generally satisfying.

How to cite: Walter, P. J., Mohan, R., & Amsel, B. J. (1992). Quality of life after heart valve replacement. The Journal of heart valve disease, 1(1), 34–41.

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How to cite: Starr, A., & Grunkemeier, G. L. (1992). An artificial valve--a real life. The Journal of heart valve disease, 1(1), 32–33.

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How to cite: Bortolotti U. (1992). The problem of reoperation in bioprosthetic valve recipients. The Journal of heart valve disease, 1(1), 29–31.