Chronic intravascular haemolysis after aortic disc valve replacement. Comparative study between Lillehei-Kaster and Björk-Shiley disc valve prostheses

Dual detection of chromatin accessibility and DNA methylation using ATAC-Me

The epigenome is multidimensional, with individual molecular components operating on different levels to control transcriptional output. Techniques that combine measurements of these features can reveal their precise correspondence in genomic space, or temporal connectivity, to better understand how they jointly regulate genes. ATAC-Me is an integrated method to probe DNA methylation and chromatin accessibility from a single DNA fragment library. Intact nuclei undergo Tn5 transposition to isolate DNA fragments within nucleosome-free regions. Isolated fragments are exposed to sodium bisulfite before library amplification and sequencing. A typical ATAC-Me experiment detects ~60,000-75,000 peak regions (P < 0.05), covering ~3-4 million CpG sites with at least 5× coverage. These sites display a range of methylation values depending on the cellular and genomic context. The approach is well suited for time course studies that aim to capture chromatin and DNA methylation dynamics in tandem during cellular differentiation. The protocol is completed in 2 d with standard molecular biology equipment and expertise. Analysis of resulting data uses publicly available software requiring basic bioinformatics skills to interpret results.

LDH Levels and Left Atrial Ultrastructural Chances in Patients with Mitral Paraprosthetic Regurgitation

BACKGROUND AND AIM

The aim of this study was to assess the effect of paraprosthetic regurgitation of mitral mechanical valves to myocardial tissue and lactate dehydrogenase (LDH) level.

METHODS

We compared 19 patients (study group) who had mitral mechanical valve with severe mitral paravalvular regurgitation with 20 patients (control group) who had native valve with severe rheumatic mitral regurgitation. None of the patients had clinical hemolytic anemia. On transesophageal echocardiographic examination, semiquantative evaluation and spatial distribution of regurgitant jets were noted in both of the groups. Five LDH isoenzymes were studied in two groups. Myocardial tissue specimens were taken from the left atrial wall during reoperation. Grids randomly taken were studied under the transmission electron microscope.

RESULTS

Total serum LDH levels of the study group (578 +/- 12 IU/L) were higher than the control group (495 +/- 6.2 IU/L) (p < 0.001). We found LDH1/LDH2 more than 1 in all patients; the ratio was not statistically different in the control group. Electron microscopy revealed the same degree of injury in both groups. Haptoglobin levels were decreased and reticulocyte counts were increased in patients with paraprosthetic valve regurgitation.

CONCLUSIONS

Electron microscopic findings support that myocardial injury contributes to increase of total LDH level and high LDH1/LDH2 ratio. But statistically significant elevation in total LDH level in study group and the stable state of LDH1/LDH2 ratio between two groups showed that hemolysis caused by paraprosthetic regurgitation is the most important factor for the increase of total LDH level, so that high LDH level can be used as a reliable parameter for the diagnosis of intravascular hemolysis in paraprosthetic regurgitation.

Mechanisms of hemolysis after mitral valve repair: assessment by serial echocardiography

OBJECTIVES

We sought to determine, using serial echocardiography, the hydrodynamic mechanisms involved in the occurrence of hemolysis after mitral valve repair.

BACKGROUND

Recently, fluid dynamic simulation models have identified distinct patterns of mitral regurgitant flow disturbances in patients with mitral prosthetic hemolysis that were associated with high shear stress and may therefore produce clinical hemolysis. Rapid acceleration, fragmentation, and collision jets were associated with high shear stress and hemolysis whereas slow deceleration and free jets were not.

METHODS

We reviewed serial echocardiographic studies of 13 consecutive patients with hemolytic anemia after mitral valve repair who were referred for mitral reoperation between January 1985 and December 1996 (group 1). Thirteen patients undergoing reoperation for mitral regurgitation after mitral valve repair but without hemolysis served as controls (group 2).

RESULTS

The mitral regurgitant jet was central in origin in 12 group 1 patients and 9 group 2 patients (Fisher exact test, p= 0.3). The other patients had para-ring regurgitation. Group 1 patients had collision (n=11), rapid acceleration (n=2) or fragmentation (n=1) jets whereas group 2 patients had slow deceleration (n=11) or free jets (n=2) (Fisher exact test, p < 0.0001). One patient with hemolysis had both collision and rapid acceleration jets. The "culprit" jet could be identified on the postbypass transesophageal echocardiography (TEE) study in only 1 patient at the time of initial mitral repair. Twelve group 1 patients underwent reoperation, with subsequent resolution of hemolysis in all patients. At reoperation, the initial repair was found to be intact in 8 (67%) patients.

CONCLUSION

Distinct patterns of flow disturbance associated with high shear stress were identified by color Doppler imaging in patients with hemolysis after mitral valve repair. The majority (92%) of these color flow disturbances were not present during intraoperative postbypass TEE study after initial mitral repair and subsequently developed in the early postoperative period.

Frequency and severity of intravascular hemolysis after left-sided cardiac valve replacement with Medtronic Hall and St. Jude Medical prostheses, and influence of prosthetic type, position, size and number

Intravascular hemolysis occurs often in patients with mechanical heart valve prostheses, but in most cases is of mild degree and subclinical. The severity of hemolysis is reported to be related to the type, position and size of prostheses used, as well as the presence of valve malfunction. Hemolysis was evaluated in 170 patients with St. Jude Medical (SJM) and 80 patients with Medtronic Hall (MH) prostheses, with normal mechanical function. The presence and severity of hemolysis was assessed on the basis of serum lactic dehydrogenase, serum haptoglobin, blood hemoglobin and reticulocyte levels as well as the presence of schistocytes. Overall, patients with SJM prostheses had greater frequency (51.2 vs 18.7%, p < 0.005) and severity (p < 0.005) of hemolysis than patients with MH prostheses, irrespective of position and size. No patient had decompensated anemia. The frequency of hemolysis was similar in both groups with double-valve replacement, whereas severity was greater with SJM than MH prostheses (p < 0.001). The number and position of the prostheses were correlated with severity of hemolysis: Double-valve replacement and mitral position were correlated with greater hemolysis than single-valve replacement (p < 0.01) and aortic position (p < 0.01). Valve size, cardiac rhythm and time from operation did not correlate either with frequency or severity of hemolysis. It is concluded that in normally functioning SJM and MH prostheses: (1) hemolysis is frequent but never severe; (2) SJM demonstrates greater frequency and severity when compared with MH valve; and (3) number, position, but not size, significantly affect the severity of hemolysis.

Indexes of intravascular hemolysis, quantification of coagulation factors, and platelet survival in patients with porcine heterograft valves

Ten patients with porcine heterograft valves who were not receiving anticoagulant agents were evaluated to determine the effect of the valve on red blood cell survival and on platelet activation and consumption as measured by (1) quantification of the coagulation mechanism, (2) platelet function studies, and (3) 51-chromium platelet survival time. There was no evidence of significant intravascular hemolysis as determined by the reticulocyte count, serum iron and iron binding capacity, serum bilirubin level, or lactic dehydrogenase activity. The coagulation profile and the platelet function studies were normal. No statistically significant difference was found in the platelet survival time in the 10 patients with porcine heterograft valves (half-life 3.2 +/- 0.8 days) and the 11 normal control subjects (half-life 3.6 +/- 0.6 days) (p greater than 0.2). The finding of a normal platelet survival time in patients with porcine heterograft valves is consistent with clinical experience indicating that this device is associated with a low incidence of systemic embolization, approximating 3% per year.

Chronic intravascular hemolysis after aortic valve replacement with Ionescu-Shiley xenograft: comparative study with Bjork-Shiley prosthesis

Twenty patients with a prosthetic valve (Ionescu-Shiley or Bjork-Shiley) in the aortic position were studied for evidence of intravascular hemolysis. Serum lactic dehydrogenase and serum haptoglobin levels were used as the most sensitive indicators of hemolysis. Elevated concentrations of lactic dehydrogenase were found in all 10 patients with an Ionescu-Shiley prosthesis (mean 402 IU/liter) and in 7 of 10 patients with a Bjork-Shiley prosthesis (mean 234 IU/liter). The mean serum haptoglobin was 15 mg/dl (range 10 to 28) in patients with the Ionescu-Shiley valve and 96 mg/dl (15 to 284) for those with the Bjork-Shiley valve. This study indicates the presence of chronic intravascular hemolysis in patients with the Ionescu-Shiley aortic valve. The increase in lactic dehydrogenase was significantly greater in patients with the Ionescu-Shiley prosthesis than in those with the Bjork-Shiley prosthesis, indicating a slightly shorter red cell life span in the former group.

Mechanical haemolytic anaemia after valve repair operations for non-rheumatic mitral regurgitation

Two cases are described in which severe mechanical haemolytic anaemia developed shortly after operation for repair of non-rheumatic mitral regurgitation. One patient had a "floppy" valve and the other cleft mitral leaflets, and both had chordal rupture. In both there was residual regurgitation after repair though in one this was initially only trivial. Clinically manifest haemolysis ceased after replacement of the valve by a frame-mounted xenograft. There are two previously reported cases in which haemolytic anaemia followed an unsuccessful mitral valve repair operation. Subclinical haemolysis or mild haemolytic anaemia may occur with unoperated valve lesions, but hitherto frank haemolytic anaemia has been observed only when turbulent blood flow is associated with the presence of a prosthetic valve or patch of prosthetic fabric. In these four cases, however, polyester or Teflon sutures were the only foreign material, and it is suggested that when these are used for the repair of leaflets, particularly in non-rheumatic mitral valve disease, they may increase the damaging effect of turbulence on circulating red blood cells.

Chronic haemolysis after Lillehei-Kaster valve replacement. Comparison with the findings after Björk-shiley and Starr-Edwards mitral valve replacement

Nineteen female and sixteen male patients who have had their heart valves replaced with Lillehei-Kaster valves were investigated for haemolysis four to 18 months after operation. Investigation included serum lactic dehydrogenase, serum haptoglobins, and urine haemosiderin. Red cells survival, using autologous red cells labelled with 51Cr, was measured in 12 patients. No patient showed manifest anaemia. The serum lactic dehydrogenase levels were raised in 66% of the mitral valve patients, 81% of the aortic valve patients, and in all the double valve patients. The serum haptoglobins were decreased in 66% of mitral patients, 68% of aortic valve patients, and in 75% of the double valve patients. All the 12 patients studied had lower than normal red cell survivals. No correlation was found between the incidence of haemolysis and the size of the valve. In isolated mitral valve replacement 66% showed compensated haemolysis compared with 42% in Björk-Shiley valves (p less than 0.05), 85% in Starr-Edwards valves (composite seat) (p less than 0.01), and none in frame-mounted irradiated homografts (previous study) (p less than 0.001).

Intravascular haemolysis after valve replacement: comparative study between Starr-Edwards (ball valve) and Björk-Shiley (disc valve) prosthesis

Seventy-four patients with single prosthetic valves (Björk-Shiley or Starr-Edwards) in the mitral or aortic position and 18 controls with rheumatic valvar heart disease were investigated for evidence of intravascular haemolysis. Serum lactate dehydrogenase (LDH) was used as the most sensitive indicator of haemolysis. Raised concentrations were found in a third of 39 patients with Björk-Shiley prostheses (mean 281 IU/l) and in all 35 patients with Starr-Edwards prostheses (mean 859 IU/l. Values were considerably higher in patients with Starr-Edwards prostheses and particularly in those with aortic prostheses (mean 927 IU/l). Eight out of 12 patients with haemosiderinuria had Starr-Edwards valves. Intravascular haemolysis was of little clinical significance in patients with Björk-Shiley prostheses, but some patients with Starr-Edwards prostheses became iron deficient as a result.

CREATION OF A SECONDARY VENTRICULAR OUTLET TO REVERSE HEMOLYSIS AFTER AORTIC VALVE REPLACEMENT

A 66-year-old woman developed severe hemolysis after undergoing aortic valve replacement. A diminutive annulus and extensive calcification of the aorta precluded further surgery of the aortic root. Hemolysis was completely reversed by the implantation of a woven Dacron apicoabdominal aortic conduit incorporating a Cooley-Cutter prosthetic valve. Fractionation of stroke volume by means of a second ventricular outlet can reduce shear stresses and turbulence associated with unfavorable hemodynamic conditions, thereby successfully correcting hemolysis.

Aortic valve replacement. A randomized study comparing Björk-Shiley and Lillehei-Kaster disc valves. Haematological evaluation

In this study, 79 randomized patients with either Björk-Shiley (B-S) or Lillehei-Kaster (L-K) aortic disc valves were re-admitted two years after operation for clinical, haemodynamic and haematological evaluation. This paper deals in particular with the haematological results. Cine-aortography was carried out in 76 patients and left ventricular catheterization via the transseptal approach was performed in 43 patients. Haemoglobin concentration, erythrocyte count, platlet count, reticulocyte count, plasma haemoglobin concentration, serum bilirubin, serum iron, serum haptoglobin and serum lactate dehydrogenase were studied in the patients. Postoperatively all patients had normal haemoglobin and erythrocyte count. Haptoglobin was absent or reduced in 43% of patients with B-S valves and in 65% of those with L-K valves. Serum lactate dehydrogenase activity (LDH) was abnormally elevated in 26% of patients in the B-S group and in 65% of those in the L-K group. Mean LDH was significantly higher in the L-K group compared with the B-S group (p less than 0.01). A highly significant linear correlation could be demonstrated between mean systolic pressure difference across the valve (delta pm) and LDH (p less than 0.001). This finding helps to explain why the L-K valves provoke more erythrocyte destruction than the B-S valves, since delta pm proved to be significantly higher in the L-K group. LDH was not significantly increased in 6 patients in whom a paravalvular leakage was demonstrated.

Chronic haemolysis following combined mitral and aortic valve replacement. A randomized study between the Björk-Shiley and Lillehei-Kaster disc valve prostheses

Intravascular haemolysis was studied in a randomized series of 35 patients examined 12--24 months after combined mitral and aortic valve replacements with either the Björk-Shiley (pyrolytic carbon) tilting disc valve (19 patients) or the Lillehei-Kaster pivoting disc valve (16 patients). Red blood cell count, haemoglobin concentrations, and serum bilirubin varied within normal ranges with a few exceptions. Haptoglobin was absent or reduced in 86%, while elevated values for serum lactate dehydrogenase were found in 82%. The increase in serum lactate dehydrogenase activity was moderate and indicated a normal or only slightly reduced red cell lifespan in most patients. Although the intravascular haemolysis was of little clinical significance, the increase in lactate dehydrogenase was significantly higher in patients with the Lillehei-Kaster prosthesis than in patients with the Björk-Shiley prosthesis, indicating a slightly shorter lifespan in the former group. For both models, however, intravascular haemolysis was less severe than previously reported after combined aortic and mitral valve replacement with ball valve prosthesis.

Intravascular hemolysis in the late course of aortic valve

The degree of intravascular hemolysis was evaluated in 315 patients in the late course of aortic valve replacement. Starr-Edwards aortic ball valves of series 2300 caused significantly more hemolysis than did those of series 1200, as estimated from the serum lactate dehydrogenase levels. Smaller valves of series 2300 caused a higher degree of hemolysis than did the larger ones. Aortic disc valves induced a more moderate red cell destruction than did the ball valves, the Lillehei-Kaster significantly more than the Bjørk-Shiley prostheses. Crushing of red cells is thought to be a more important cause of hemolysis than shearing forces in turbulent blood. Hemolytic anemia represented a problem only in some patients with Starr-Edwards valve type 2300, although iron substitution was necessary also in some with other prostheses, since the hemoglobin-binding capacity of haptoglobin was exceeded in several patients. Valvular or paravalvular leakage was associated with stronger hemolysis in some patients, and should be suspected whenever the rate of red cell destruction increases. Longstanding intravascular hemolysis did not seriously affect renal function.

Arterial thromboembolic complications in patients with Björk-Shiley and Lillehei-Kaster aortic disc valve prostheses

Arterial thromboembolic complications were studied in 196 patients who had either a single Björk-Shiley or Lillehei-Kaster aortic disc valve implanted. Eight patients suffered from such complications in the course of the first postoperative month and three of them died, two from myocardial infarction and one from cerebral embolism. Nineteen late thromboembolic complications developed in 18 of the 164 patients who survived the postoperative period, the incidence bein 5.9 episodes per 100 patients per year. The two valve types wer found to be equallly thrombogenic, and the rate was not lower than that in patients with Starr-Edwards aortic ball valves of series 2,300 previously studied. Particularly serious was valve malfunction caused by thrombi that limited the movement of the discs. Early recognition of this condition is essential, because the only effective therapy is removal of the thrombus. Three patients with a Björk-Shiley and one with a Lillehei-Kaster valve suffered this complecation and two died, while cerebral embolism caused a third late death. Two of the three patients who had not received anticoagulants developed thromboembolic complications, while most episodes occurred in spite of well-maintained anti-coagulant treatment. It is concluded that arterial thromboembolic complications remain a considerable problem also after aortic disc valve implantation, and that thrombotic valve malfunction is particularly serious and requires special attention.

In vivo evaluation of the Lillehei-Kaster heart valve prosthesis

In vivo evaluation of the Lillehei-Kaster heart valve prosthesis was performed in 28 patients; 22 had undergone aortic valve replacement and 6 had had mitral valve replacement. Mean pressure gradients ranged from 6 to 53 mm Hg in aortic prostheses; valve area varied from 0.83 to 2.9 cm2. The maximum opening angle of 80 degrees was never reached in this group of patients; opening angles ranged from 57 to 74 degrees without evidence of disc malfunction. There was no correlation between the ratio of effective to geometric valve area and the degree of opening of the disc occluder. Similar results were found in the mitral valve group. Gradients ranged from 6.0 to 12.5 mm Hg and valve area from 1.6 to 2.2 cm2. The maximum opening angle was 59 to 63 degrees. It is concluded that incomplete opening of the disc occluder in pivoting-disc valves is not necessarily a sign of disc malfunction. Lillehei-Kaster valves smaller than 18 mm in internal diameter should be avoided in adults, and outflow aortoplasty for implantation of a larger prosthesis should be used in patients who have a narrow aortic root.

Haemolysis after mitral valve replacement with the Björk-Shiley and the Lillehei-Kaster disc valve prosthesis

The present study reports on the incidence and degree of intravascular haemolysis in 33 patients with Björk-Shiley tilting disc prosthesis and in 34 patients with Lillehei-Kaster pivoting disc valve prosthesis in the mitral position examined 12 to 24 months after the operation. Serum haptoglobin, serum lactate dehydrogenase, serum bilirubin, and haemoglobin estimations were performed. Significant haemolysis was detected in 85 per cent of the patients. Haptoglobin was absent or reduced in 72 per cent, while raised values for serum lactate dehydrogenase were found in 43 per cent. The increase in lactate dehydrogenase was moderate and showed no correlation with blood flow through the prosthesis or with the gradient across the prosthesis. Most patients had normal haemoglobin and normal serum bilirubin values. Although intravascular haemolysis was of little clinical significance, the increase in lactate dehyrdrogenase was significantly higher in patients with the Lillehei-Kaster prosthesis than in patients with the Björk Shiley prosthesis, indicating a slightly shorter red cell lifespan in the former group. The possible reasons for the difference between the two groups are discussed.

Hemolysis in the aortic prosthetic valve

A review of the incidence and severity of hemolysis in the aortic prosthesis is presented. The noncloth-covered Starr-Edwards prosthetic series 1000, 1200, and 1260 had a 2 percent (1/54) incidence of anemia. The cloth-covered Starr-Edwards aortic prosthetic series 2300 was associated with anemia in 61 percent (28/46) of patients. The modified aortic prosthetic series 2310 and 2320 had a 34 percent (19/56) incidence. Mean lactic dehydrogenase levels for the series 1000, 1200 and 1260 were 184 units; 2300 series, 574 units; 2310 and 2320 series, 334 units; and the Bjork-Shiley aortic prosthesis, 166 units. Nine patients underwent repeat surgery because of refractory anemia in the 2300 series, and one did so in the 2310 series. Four of the patients with repeat surgery had significant cloth wearing of the valve. A transvalvular gradient in excess of 30 mm Hg was present in seven of ten anemic patients studied who had the series-2300 valve. The cloth-covered Starr-Edwards aortic prosthesis carries a significant risk of anemia. At the present time the 2310 and 2320 series cause less hemolysis and a lower incidence of anemia than the original 2300 series but in excess of the noncloth-covered Starr-Edwards prosthesis.