Late incidence and predictors of persistent or recurrent heart failure in patients with mitral prosthetic valves

OBJECTIVE: The study's objective was to examine factors associated with persistent or recurrent congestive heart failure after mitral valve replacement. METHODS: Patients who underwent mitral valve replacement with contemporary prostheses (N = 708) were followed with annual clinical assessment and echocardiography. Cox proportional hazard models were developed to evaluate the impact of demographic, comorbid, and valve-related variables on the occurrence of congestive heart failure after mitral valve replacement, defined as the composite outcome of New York Heart Association class III or IV symptoms or death caused by congestive heart failure postoperatively. Factors associated with all-cause mortality were also examined. Models were bootstrapped 1000 times. RESULTS: The total follow-up was 3376 patient-years (mean 4.8 +/- 3.7 years, range 60 days to 17.1 years). Freedom from New York Heart Association III or IV symptoms or death caused by congestive heart failure was 96.1% +/- 0.8%, 82.7% +/- 1.7%, 66.4% +/- 3.0%, and 38.8% +/- 6.9% at 1, 5, 10, and 15 years, respectively. Preoperative New York Heart Association class, left ventricular grade, atrial fibrillation, coronary artery disease, smoking, persistent tricuspid regurgitation, and redo status predicted congestive heart failure postoperatively (all P <.05). Patients who underwent mitral valve replacement for pure mitral stenosis had less congestive heart failure events after surgery than those with regurgitation or mixed disease. Prosthesis size and elevated transprosthesis gradients were not predictive of freedom from congestive heart failure after mitral valve replacement. Atrial fibrillation, persistent tricuspid regurgitation, and surgical referral for mitral valve replacement at an advanced functional stage were also risk factors for all-cause mortality. CONCLUSIONS: This study identifies the incidence of and risk factors for congestive heart failure and death late after mitral valve replacement. Although prosthesis size has no effect, other potentially modifiable factors such as atrial fibrillation, persistent tricuspid regurgitation, and late surgical referral have a negative impact on freedom from congestive heart failure and overall survival after mitral valve replacement.     

Late incidence and predictors of persistent or recurrent heart failure in patients with aortic prosthetic valves

BACKGROUND: We examined factors associated with persistent or recurrent congestive heart failure after aortic valve replacement. METHODS: Patients who underwent aortic valve replacement with contemporary prostheses (n = 1563) were followed up with annual clinical assessment and echocardiography. The effect of demographic, comorbid, and valve-related variables on the composite outcome of New York Heart Association class III or IV symptoms or congestive heart failure death after surgery was evaluated with stratified log-rank tests, Cox proportional hazard models, and logistic regression. Factors associated with all-cause death were also examined. Prediction models were bootstrapped 1000 times. RESULTS: Total follow-up was 6768 patient-years (mean, 4.3 +/- 3.3 years; range, 60 days to 17.1 years). Freedom from congestive heart failure or congestive heart failure death was 98.6% +/- 0.3%, 88.6% +/- 1.0%, 73.9% +/- 2.3%, and 45.2% +/- 8.5% at 1, 5, 10, and 15 years, respectively. Age, preoperative New York Heart Association class, left ventricular grade, atrial fibrillation, coronary artery disease, smoking, and redo status predicted congestive heart failure after surgery (all P <.05). Larger prosthesis size and effective orifice area, both absolute and indexed for body surface area, were independently associated with freedom from congestive heart failure. Increased transprosthesis gradients were predicted by prosthesis-patient mismatch and were associated with congestive heart failure after surgery. Mismatch defined as an effective orifice area/body surface area of 0.80 cm(2)/m(2) or less was a significant predictor of congestive heart failure events after surgery, but mismatch defined as an effective orifice area/body surface area of 0.85 cm(2)/m(2) or less was not. Small prosthesis size and mismatch were not significantly associated with all-cause mortality. CONCLUSIONS: These analyses identify independent predictors of congestive heart failure symptoms and congestive heart failure death late after aortic valve replacement and indicate that prosthesis size has a significant effect on this cardiac end point, but not on overall survival after aortic valve replacement.     

The determinants of survival following reoperation on prosthetic cardiac valves

In an effort to identify the determinants of survival following reoperation on patients with prosthetic cardiac valves, the experience with a group of 33 patients at the University of Rochester Medical Center was reviewed. The survival rate was 58% (19/33). Survival was not related to the valve involved, the age of the patient, or the technical hazards of a second cardiac operation. Ten (77%) of the 13 patients in New York Heart Association (NYHA) Functional Class II survived compared with 8 (40%) of the 20 in Class III or IV. The survival rate for patients with a paravalvular fistula was 79% (11/14); with valve dysfunction, 50% (6/12); and with prosthetic valve infection, 29% (2/7). The determinants of survival seem to be similar to those for primary operation (i. e., NYHA patient classification and indication for operation) and less related to the potential operative complications of a reoperation.     

Platelet survival in patients with homograft and prosthetic heart valves: Correlation with incidence of thromboembolism

Manohitharajah, S. M., Rahman, A. N., Donnelly, R. J., Deverall, P. B., and Watson, D. A. (1974).Thorax, 29, 639-642. Platelet survival in patients with homograft and prosthetic heart valves. Investigations in the past have demonstrated shortened platelet survival time in patients with prosthetic heart valves. This suggested that platelets contribute to thromboembolism in this group. Homograft valves and the newer models of the Starr-Edwards prosthesis have proved less thrombogenic than those previously employed, but platelet survival studies in patients with these valves are lacking. In this study platelet function, survival, and its relation to haemolysis were determined in 28 patients following mitral valve replacement and in two patients following mitral valvotomy: 14 patients had a frame-mounted homograft aortic valve; 13 patients had a Starr-Edwards prosthesis model 6310 or 6320, and one had a Starr-Edwards prosthesis model 6000. Normal platelet function and survival was found in both the homograft and the Starr valve groups. The patient with the earlier model of the Starr valve (model 6000) had a shortened platelet survival time. The two patients following mitral valvotomy had normal platelet survival. The fact that platelet abnormalities were not demonstrable in our patients with homograft valves and newer Starr-Edwards prostheses may explain the low incidence of thromboembolism in this group. Platelet survival studies are a useful parameter to determine the potential thrombogenic nature of prosthetic valves. Platelet survival time was not influenced by the presence or severity of haemolysis.     

Surgical treatment of the prosthetic valves in reoperation

Surgical treatment and problems in patients required reoperation for malfunctioning prosthetic valves are reviewed in our institute. The cinefluoroscopy and pulse doppler echocardiography were helpful for diagnosis of artificial valve dysfunction. In recent two decades valve replacement were performed in 382 cases and number of re-implanted valve were 469. Among them the cases of reoperation were 21 and reimplanted valves were 25 (5.6%); 4.7% in aortic, 5.0% in mitral, 6.7% in tricuspid position. Three cases of those patients had three operations. Main causes of reoperation were primary tissue failure in Carpentier-Edwards porcine xenograft (6 cases, 23%) and cloth wear in Starr-Edwards ball valve (9 cases, 38%) and thrombosis in St. Jude Medical bi-leaflet valve (3 cases, 15%). In most cases St. Jude Medical valve were chosen for the alternative prosthetic valve in reoperation. We applied IABP support to seven patients for severe low cardiac output syndrome after the operation and overall mortality was 24% in reoperation. It concluded that St. Jude Medical valve may be most reliable because of low incidence of postoperative complication in our institute.     

Ventricular assist device in patients with prosthetic heart valves

Ventricular assist device (VAD) support inpatients with a prosthetic heart valve had previously been considered a relative contraindication due to an increased risk of thromboembolic complications. We report our clinical experience of VAD implantation in patients with prosthetic heart valves, including both mechanical and bioprosthetic valves. The clinical records of 133 consecutive patients who underwent VAD implantation at a single institution from January 2002 through June 2009 were retrospectively reviewed. Six of these patients had a prosthetic valve in place at the time of device implantation. Patient demographics,operative characteristics, and postoperative complications were reviewed.Of the six patients,four were male.The mean age was 57.8 years (range 35–66 years). The various prosthetic cardiac valves included a mechanical aortic valve (n = 2), a bioprosthetic aortic valve (n = 3), and a mechanical mitral valve (n = 1).The indications for VAD support included bridge to transplantation (n = 2), bridge to recovery (n = 1), and postcardiotomy ventricular failure(n = 3). Three patients underwent left ventricular assist device placement and three received a right ventricular assist device. Postoperatively, standard anticoagulation management began with a heparin infusion (if possible)followed by oral anticoagulation.The 30-day mortality was50% (3/6). The mean duration of support among survivors was 194.3 days (range 7–369 days) compared with 16.0 days(range 4–29 days) for nonsurvivors. Of the three survivors,two were successfully bridged to heart transplantation and one recovered native ventricular function.Among the three nonsurvivors,acute renal failure developed in each case, and two developed heparin-induced thrombocytopenia. This study suggests that VAD placement in patients with a prosthethic heart valve, either mechanical or bioprosthetic,appears to be a reasonable option.     

Microembolic signal counts increase during hyperbaric exposure in patients with prosthetic heart valves.

BACKGROUND: Patients with prosthetic heart valves have an increased risk of thromboembolic events, and transcranial Doppler sonography reveals microembolic signals. Whereas microembolic signals were initially assumed to be of particulate matter, recent studies suggest that they are partially gaseous in origin. If this is true, alteration of environmental pressure should change microembolic signal counts. We undertook this study to evaluate the influence of hyperbaric exposure on microembolic signal counts in persons with prosthetic heart valves. METHODS AND RESULTS: Microembolic signal counts were monitored by transcranial Doppler sonography of both middle cerebral arteries under normobaria (normobaria 1), 2 subsequent periods of hyperbaria (2.5 and 1.75 bar), and a second period of normobaria (normobaria 2) in 15 patients with prosthetic heart valves. Each monitoring period lasted 30 minutes. Compression and decompression rates were 0.1 bar/min. Microembolic signal counts increased from 20 (12-78) at normobaria 1 to 79 (30-165) at 2.5 bar (P <.01 vs normobaria 1 and 2), decreased to 44 (18-128) at 1.75 bar (P <.01 vs normobaria 1 and 2.5 bar; P <.001 vs normobaria 2), and returned to 20 (8-96) at normobaria 2 (values are medians and 95% confidence intervals). CONCLUSIONS: Our results strongly suggest that gaseous bubbles are underlying material for part of the microembolic signals detected in patients with prosthetic heart valves.     

Management of anticoagulant therapy during pregnancy in patients with prosthetic heart valves

We describe two patients with Starr-Edwards mitral valve replacements who underwent pregnancy on oral anticoagulants and who were successfully delivered of live babies. The literature on pregnancy with prosthetic heart valves is reviewed. It is suggested that properly controlled oral anticoagulation should be continued until the onset of labour; the anticoagulant effect should then be reversed by an intravenous infusion of fresh-frozen plasma and the patient maintained on intravenous heparin injections six-hourly. Oral anticoagulants should be restarted immediately after delivery and the heparin withdrawn only when their effect has been re-established.     

Pregnancy in patients with mechanical prosthetic heart valves. Our experience regarding 98 pregnancies in 57 patients

Ninety-eight pregnancies in 57 patients with mechanical (ball or tilting disc) prosthetic heart valves are described. Sixty-one pregnancies developed in 36 patients with a mitral prosthesis, 12 pregnancies in 9 patients with an aortic prosthesis, 17 pregnancies in 10 patients with both mitral and aortic prostheses and 8 pregnancies in 2 patients with mitral and tricuspid prostheses. All patients were in I or in II NYHA class at conception and no significative change was noted during pregnancy. All the patients were treated with oral anticoagulant therapy at conception. Different kinds of antithrombotic and antiembolic prophylaxis were employed. There were 13 voluntary interruptions of pregnancy and 37 spontaneous abortions. In the 47 newborn 2 malformation complications (1 warfarin syndrome, 1 cleft palate) and 4 haemorrhagic complications (without sequelae) were noted. Two fatal thromboses of a mitral prosthesis occurred; systemic embolic complications were noted in 7 cases. These observations suggested different incidences of complications regarding the antithrombotic and anti-embolic prophylaxis. The authors point out the high risk of thrombotic and embolic complications and the low rate of successful outcome of pregnancy in these patients.     

Pregnancy in patients with prosthetic cardiac valves

Thirty-seven pregnancies in 33 patients who had prosthetic cardiac valves inserted at Baragwanath Hospital are reviewed. The patients were divided into three groups, as determined by fetal and maternal outcome. There were 31 live births, and the patients seemed to deal well with the haemodynamic stresses of pregnancy. There were 2 maternal deaths, and 6 patients required a second valve replacement during the pregnancy under review. The problem of longterm anticoagulant therapy and its management is discussed.     

Experiences with 1643 porcine prosthetic valves in 1492 patients.

Sixteen hundred and forty-three porcine prosthetic values (1102 Carpentier-Edwards, 541 Hancock) were implanted in 1492 patients at New York University Medical Center between January 1976 and June 1983. The aortic valve alone was replaced in 786 patients (53%), mitral valve alone in 556 (37%), and multiple valves in 143 patients (9.6%). Concomitant coronary artery bypass was performed in 326 patients (22%). There were 116 deaths within 30 days of operation (7.8%). Follow-up (mean: 42 months) was completed in 94% of survivors and revealed that late survival from cardiac-related death was 87% at 5 years and 81% at 7 years, with no significant difference between the Carpentier-Edwards and Hancock patients. Late thromboembolic complications, however, were significantly more frequent in Hancock patients at all intervals from 1-7 years (p less than 0.05), whether in the aortic or mitral position. Patients with coronary artery disease who had concomitant coronary bypass showed a survival from late cardiac death that did not differ significantly from that of patients undergoing valve replacement alone. Before operation, 87% of patients were in New York Heart Association Class III or IV, but after operation 80% were in Class I or II. Late anticoagulant complications, endocarditis, and valve dysfunction were relatively rare. These results from a series of such size, duration, and representative numbers of two types of porcine bioprosthesis confirm excellent results with porcine prostheses in the first 4-5 years following operation.     

Clinical experience with omniscience and omnicarbon prosthetic heart valves

Omniscience valves were implanted in sixty-two patients. Twenty-eight of these patients underwent aortic valve replacement (AVR), 15 had mitral valve replacement (MVR) and 8 had aortic and mitral valve replacement (DVR). Post-operative events occurred in nine (5.9%/patient year) of the AVR group, in three (1.7%/patient year) of the MVR group and in three (5.4%/patient year) of the DVR group. The actuarial freedom from all events at five years in the AVR, MVR and DVR was 74 +/- 8%, 88 +/- 6%, 67 +/- 16%, respectively. Cardiac death occurred in four (2.5%/patient year) of the AVR, one (0.6%/patient year) of the MVR and two (3.6%/patient year) of the DVR. The freedom at five years in the AVR, MVR and DVR was 88 +/- 6%, 96 +/- 4%, and 77 +/- 14%, respectively. Valve-related complications were noted in four patients. Post-operative cerebral hemorrhage was seen in three of the AVR. Maximum opening angle of the Omniscience valve was 39.1 +/- 4.5 degrees at the aortic position and 44.6 +/- 9.7 degrees at the mitral position. Omnicarbon valves implanted in ninety-five patients, fifty-eight of these patients underwent AVR, 24 had MVR and 13 had DVR. Events occurred post-operatively in four (2.6%/patient year) of the AVR group, in three (12.2%/patient year) of the MVR group, but in none of the DVR group. The freedom at five years was 89 +/- 6% in the AVR and 84 +/- 8% at three years in the MVR. Post-operative cardiac death occurred in one (0.7%/patient year) of the AVR and in two (8.1%/patient year) of the MVR.(ABSTRACT TRUNCATED AT 250 WORDS)     

Intravascular hemolysis in patients with new-generation prosthetic heart valves: a prospective study

OBJECTIVE: A prospective clinical study was designed to assess the frequency and severity of intravascular hemolysis in patients with new-generation, normally functioning prosthetic heart valves. METHODS: Hemolysis was evaluated in 172 patients with a mechanical prosthesis (53 CarboMedics and 119 Sorin Bicarbon) and in 106 patients with a bioprosthesis (15 St Jude Medical Toronto, 19 Baxter Perimount, and 72 Medtronic Mosaic) in the aortic position, mitral position, or both. Aortic valve replacement was performed in 206 patients, mitral valve replacement in 59 patients, and double valve replacement in 13 patients. The presence of hemolysis was assessed on the basis of the level of serum lactic dehydrogenase and serum haptoglobin and the presence and amount of reticulocytes and schistocytes in the peripheral blood. Severity of intravascular hemolysis was estimated on the basis of serum lactic dehydrogenase. Clinical, echocardiographic, and hematologic evaluations were performed 1, 6, and 12 months after discharge. RESULTS: None of the 278 patients experienced decompensated anemia, whereas at 12 months, mild subclinical hemolysis was identified in 49 patients, 44 (26%) with a mechanical prosthesis and 5 (5%) with a bioprosthesis (P <.001). At multivariate analysis, independent predictors of the presence of subclinical hemolysis were mitral valve replacement (P <.001), use of a mechanical prosthesis (P =.002), and double valve replacement (P =.02). Frequency of hemolysis in patients with stented aortic bioprostheses was 3%, whereas it was absent in those with stentless valves. Among mechanical valve recipients, double versus single valve replacement (P =.04) and mitral versus aortic valve replacement (P =.05) were correlated with the presence of hemolysis; double valve recipients also showed a more severe degree of hemolysis (P =.03). In patients with a Sorin Bicarbon prosthesis, hemolysis was less frequent (22% vs 34%, P =.09) and severe (P <.001) than in those with a CarboMedics prosthesis. CONCLUSIONS: In normally functioning prosthetic heart valves, subclinical hemolysis is a frequent finding. A low incidence of hemolysis is found in stented biologic prostheses, and it is absent in stentless aortic valves. Modifications of valve design may contribute to minimize the occurrence of hemolysis in mechanical prostheses.