Twelve years' clinical experience with the CarboMedics prosthetic heart valve

BACKGROUND AND AIM OF THE STUDY: The CarboMedics bileaflet prosthetic heart valve was first implanted as part of a prospective clinical study at the authors' institution in November 1987. The patient cohort included was part of a multicenter trial set up by the manufacturer for an FDA application. The present report details findings over a 12-year period, with a continuous follow up on this patient cohort. METHODS: Between November 1987 and August 1990, 132 patients (68 males, 64 females; median age 56 years; range 12-74 years) received a CarboMedics heart valve prosthesis. All patients were included in the study, whether surgery was elective or emergency, first time or reoperation. There were 69 aortic, 49 mitral and 12 double (aortic + mitral) valve replacements. Two patients had isolated tricuspid valve replacement. Concomitant surgery was performed in 15 patients. Anticoagulation with warfarin was started on postoperative day 1. After discharge, patients were examined regularly as outpatients for up to five years. Subsequent follow up was obtained prospectively by questionnaires to the patients' general practitioner, or by telephone calls. Actuarial estimates of survival and freedom from morbid events were calculated using the Kaplan-Meier method; 95% confidence limits for the distribution function were calculated according to the Greenwood formula. RESULTS: Complete follow up information was available for 94% of the patients; total follow up was 1,014.3 patient-years (pt-yr). Actuarial survival at 12 years was 62 +/- 0.5% overall (61 +/- 6.5% for aortic; 66 +/- 7.5% for mitral; 65 +/- 14.0% for double valve replacements). Actuarial rates of freedom from complications were: valve thrombosis 100%, embolism 92 +/- 2.8%, and anticoagulant-related bleeding 77 +/- 5.6%. The linearized rates per 100 pt-yr were: embolism 0.89 (aortic 0.74, mitral 1.30); anticoagulant-related bleeding 2.56; paravalvular leakage overall 0.20 (aortic 0.37); prosthetic valve endocarditis overall 0.20 (aortic 0.37). There was no hemolysis, prosthetic valve dysfunction or structural deterioration. CONCLUSION: Over a 12-year time frame, the CarboMedics prosthetic heart valve has proven to be a highly reliable device with no structural failures, and a low incidence of valve-related complications.     

Fifteen years' clinical experience with the CarboMedics prosthetic heart valve

BACKGROUND AND AIM OF THE STUDY: The CarboMedics bileaflet prosthetic heart valve was first implanted as part of a prospective clinical study at the authors' institution in November 1987. The patient cohort included was part of a multicenter trial set up by the manufacturer for an FDA application. The present report details findings over a 15-year period, with a continuous follow up on this patient cohort. METHODS: Between November 1987 and August 1990, 132 patients (68 males, 64 females; median age 56 years; range: 12-74 years) received a CarboMedics heart valve prosthesis. All patients were included in the study, whether surgery was elective or emergency, first time or reoperation. There were 69 aortic, 49 mitral and 12 double (aortic and mitral) valve replacements. Two patients had isolated tricuspid valve replacement. Concomitant surgery was performed in 15 patients. Anticoagulation with warfarin was started on postoperative day 1. After discharge, patients were examined regularly as outpatients for up to five years. Subsequent follow up was obtained prospectively by questionnaires to the patients' general practitioners and with telephone calls to the patients. Actuarial estimates of survival and freedom from morbid events were calculated using the Kaplan-Meier method; 95% confidence limits for the distribution function were calculated according to the Greenwood formula. RESULTS: Complete follow up information was available on 94% of the patients; total follow up was 1,270.3 patient-years (pt-yr). Actuarial survival at 15 years was 51+/-4.9% overall; 56+/-6.2% for single aortic, 51+/-8.0% for single mitral, and 30+/-15.9% for double valve replacements. Actuarial rates of freedom from complications were: valve thrombosis 100%, embolism 89+/-3.3%, and all anticoagulant-related bleeding 76+/-4.5%. The linearized rates per 100 pt-yr were: embolism 0.94 (aortic 0.74, mitral 1.25); anticoagulant-related bleeding 2.28; paravalvular leakage overall 0.24 (aortic 0.29); prosthetic valve endocarditis overall 0.24 (aortic 0.29, mitral 0.21). There was no hemolysis, prosthetic valve dysfunction, or structural deterioration. CONCLUSION: Over a 15-year time frame, the CarboMedics prosthetic heart valve has proven to be a highly reliable device with no structural failures and a low incidence of valve-related complications.     

Mid-term results after heart valve replacement with the CarboMedics bileaflet prosthesis: experience with 785 implants.

BACKGROUND: The aim of the study was to evaluate our clinical experience with the CarboMedics Heart Valve Prosthesis. METHODS: Between October 1991 and December 1997, six hundred seventy-two consecutive patients (361 men, 54%; 311 women, 46%; mean age 57 +/- 12 year, range 6-73 years) underwent mechanical valve implantation at the Division of Cardiac Surgery of the University of Verona. Preoperatively, 69% of the patients were in NYHA FC III or IV. Eighty-one patients (12%) had undergone a previous cardiac operation and 14.5% had an ejection fraction less than 35%. We performed an aortic valve replacement in 309 patients (78 valved-conduits for replacement of the entire aortic root), a mitral valve replacement in 250, and a double valve in 113. 52 patients (8%) underwent associated myocardial revascularization. RESULTS: Early mortality was 2.8% (5/309 aortic, 1.6%; 11/250 mitral, 4.4%; 3/113 double, 2.6%). Late mortality was 4.4%. Actuarial survival at 5 years was 89.3% (aortic, 91.1%, mitral 86.4%, double 90.5%). Thromboembolism occurred in 26 patients (3.9%) and major hemorrhagic events in 20 (3%). Nine patients (1.3%) required a reoperation, in 3 cases (0.4%) after endocarditis (Staphylococcus epidermidis). No structural deterioration occurred in our series. CONCLUSION: Our study appears to confirm the safety and reliability of the CarboMedics mechanical valve prosthesis, even in old age groups. This bileaflet prosthesis demonstrates no structural deterioration, a low incidence of complications, and good hemodynamic performance.     

Mid-term results with 1,503 CarboMedics mechanical valve implants

BACKGROUND AND AIM OF THE STUDY: The CarboMedics bileaflet prosthetic heart valve was introduced in 1986, and first implanted by the authors in March 1991. The aim of this study was to analyze the authors' clinical experience with this valve. METHODS: Between March 1991 and October 1998, 1,503 valves were implanted in 1,350 patients (758 males, 592 female; mean age 62 +/- 13 years). Follow up was 99% complete and totaled 4,342 patient-years (pt-yr). Results: The hospital mortality rate was 4.3% (59/1,350). Preoperative NYHA class (p = 0.012), emergency surgery (p = 0.03) and cardiopulmonary bypass time (p = 0.01) were significantly associated with increased risk of operative death (multiple logistic regression). Mean (+/- SEM) survival rates at one and five years were 92.0 +/- 0.7% (n = 1,109) and 80.0 +/- 1.3% (n = 335). Freedom from valve-related complications (linearized rate 5.6%/pt-yr) at one and five years was 89.5 +/- 0.8% (n = 1,031) and 76.3 +/- 1.4% (n = 284). Linearized rates for bleeding events were 2.19%/pt-yr, thromboembolic events 2%/pt-yr, operated valvular endocarditis 0.18%/pt-yr, valve thrombosis 0.14%/pt-yr and non-structural dysfunction 1.22%/pt-yr. Freedom from reoperation at one and five years was 98.5 +/- 0.3% (n = 1,107) and 97.3 +/- 0.5% (n = 334). CONCLUSION: Mid-term results demonstrate that the CarboMedics prosthetic heart valve exhibits a low incidence of valve-related complications.     

Early clinical experience with the On-X prosthetic heart valve

BACKGROUND AND AIM OF THE STUDY: The study was designed to investigate the clinical performance of the On-X prosthetic heart valve in a multicenter experience. METHODS: Between September 1996 and September 1999, 301 patients (56% males) underwent isolated On-X valve replacement (184 isolated aortic (AVR), 117 isolated mitral (MVR)) at 11 European centers under a standardized protocol. Average age at implant was 60.2 years. Office or hospital follow up was required by the protocol; average follow up on all patients was 11 months. RESULTS: Thirty-day mortality in the study was 2.2% for AVR and 6.0% for MVR, with valve-related mortality of 0.5% for AVR. There were eight late deaths (0.7%/pt-yr AVR and 2.3%/pt-yr MVR). Two of these deaths were sudden, and thus possibly valve-related (one AVR, one MVR). Early total valve-related morbidity was 3.5% for AVR and 2.6% for MVR. In total, 13 thromboembolic events occurred; one early event in AVR resulted in death (0.5%), and one transient early event occurred in MVR (0.9%). There were 11 late events (seven AVR (1.7%/pt-yr) and four MVR (1.8%/pt-yr)), for a two-year freedom from thromboembolism of 96.6% after AVR and 97.1% after MVR. Three late bleeding events occurred, all after AVR (0.7%/pt-yr and 98.9% free at two years). Major paravalvular leaks requiring reoperation occurred on two occasions early (one AVR (0.5%), one MVR (0.8%)) and once late in MVR (0.5%/pt-yr). Late minor, untreated paravalvular leaks occurred in three AVR patients (0.7%/pt-yr) and in one MVR patient (0.5%/pt-yr). Prosthetic endocarditis occurred four times (two AVR (0.5%/pt-yr), two MVR (0.9%/pt-yr)), all within the first 12 months of surgery. Actuarial freedom from all valve-related events at two years was 88.7% for AVR and 88.1% for MVR. NYHA class was improved in 75.8% of AVR patients and 70.6% of MVR patients at two years after surgery. CONCLUSION: These early results indicate that the On-X valve provides satisfactory clinical outcome in the immediate postoperative period, and that the valve is both safe and effective.     

Up to nine-years' experience with the Allcarbon prosthetic heart valve

BACKGROUND AND AIM OF THE STUDY: The Allcarbon tilting disc valve has been used for valve replacement at the present authors' institution since 1993. Herein is reported their experience with Allcarbon valve implantation. METHODS: Between March 1993 and December 1998, Allcarbon valves were implanted in 599 patients (341 males, 258 females; mean age 36.2 years; range: 7-64 years). Among patients, 238 underwent mitral valve replacement (MVR), 217 aortic valve replacement (AVR), and 144 double valve replacement (DVR). The etiology of valve disease was rheumatic in 91% of cases. Follow up was 95.7% complete; cumulative follow up was 3,185 patient-years. RESULTS: Operative mortality was 2.2% (13/599). Actuarial survival at eight years was 96.6 +/- 1.2% after MVR, 96.1 +/- 1.3% after AVR, and 97.9 +/- 1.2% after DVR. Freedom from valve thrombosis at eight years was 97.0 +/- 1.3% after MVR, 100% after AVR, and 90.0 +/- 9.5% after DVR. Freedom from major bleeding at eight years was 90.0 +/- 2.7% after MVR, 93.5 +/- 2.6% after AVR, and 79.7 +/- 7.6% after DVR. There was one embolic episode after MVR. No structural valve failure was observed. Freedom from reoperation on implanted valves at eight years was 96.1 +/- 1.4% after MVR, 97.9 +/- 1.0% after AVR, and 97.9 +/- 1.5% after DVR. On completion of follow up, 91.3% of survivors were in NYHA class I, 8.5% in class II, and 0.2% in class III. CONCLUSION: Among a population of mostly young patients with rheumatic valve disease, the Allcarbon valve showed satisfactory clinical performance when implanted in the mitral and aortic positions.     

North American multicenter experience with the On-X prosthetic heart valve

BACKGROUND AND AIM OF THE STUDY: This ongoing, longitudinal, multi-center, North American study was designed to evaluate the safety and effectiveness of the On-X valve. METHODS: The On-X valve was implanted in isolated aortic (AVR) and mitral (MVR) valve replacement patients at nine North American centers. Follow up was 98.6% complete. Anticoagulation compliance was evaluated by collection of international normalized ratio (INR) results in all patients throughout their postoperative follow up. Adverse events were recorded according to the AATS/STS guidance criteria. Hematologic studies were conducted postoperatively to evaluate hemodynamics and hemolysis. RESULTS: In total, 142 AVR and 142 MVR implants were performed; the mean follow up was 4.5 years; total follow up was 1,273 patient-years (pt-yr). At implant, the mean patient age was 59.2 years (range: 28 to 85 years); 71.8% of patients who underwent AVR and 33.1% who underwent MVR were males. Preoperatively, 89.4% of AVR patients and 56.3% of MVR patients were in sinus rhythm. The cardiac disease etiology was primarily stenotic, calcific degeneration in AVR and rheumatic or degenerative regurgitation in MVR. Hemolysis represented by postoperative elevation of serum lactate dehydrogenase was very low (median 217 IU after AVR and 251 IU after MVR at one year (82% AVR and 98% MVR of upper normal). Late adverse event rates were low, most notably thromboembolism (0.9%/pt-yr after AVR; 1.6%/pt-yr after MVR) and thrombosis. Kaplan-Meier event-free rates at five years were correspondingly high. Anticoagulation compliance analysis showed only about 40% of INR readings to be within target ranges postoperatively; thus, the control range achieved was much greater than the desired target, as might generally be expected for clinic-controlled INR. CONCLUSION: The On-X valve performed well in this study, confirming the original design intent of minimal hemolysis and low adverse event rates.     

Reoperation for prosthetic heart valve dysfunction: 19 years' experience

Between September 1968 and October 1987, 152 patients (66 males and 86 females; age range, 15 to 79 years) underwent 1 or more reoperations (total, 179) for prosthetic valve dysfunction at our hospital. In this report, we present material and statistics reflecting our experience with the last reoperation in these 152 patients. The procedures involved the mitral valve in 93 patients, the aortic valve in 38 patients, double valves (aortic and mitral) in 19, and the tricuspid valve in 2. Sixty-five patients were operated on for mechanical valve dysfunction, and 87 for tissue valve dysfunction. The modes of valve dysfunction that indicated surgery were primary valve failure (85 patients), valvular thrombosis and valve-related thromboembolic episodes (27 patients), paravalvular leak (25 patients), prosthetic valve endocarditis (14 patients), and hemolysis (1 patient). Three patients were in New York Heart Association functional Class II, 77 were in Class III, and 61 were in Class IV; the remaining 11 cases were emergencies. The 30-day operative mortality was 14.5%, the 5-year survival was 75%, and the 10-year survival was 63%. The preoperative functional class and the mode of valve dysfunction significantly influenced both early and late mortality.     

Clinical experience of 473 patients with the omnicarbon prosthetic heart valve

BACKGROUND AND AIM OF THE STUDY: The long-term clinical experience of patients receiving Omnicarbon heart valve prostheses between January 1985 and December 1996 was investigated. METHODS: In total, 473 patients (255 males, 218 females; mean age 57.5 +/- 10.1 years (range: 20n-73 years) received 523 prostheses. These included 253 mitral (MVR), 170 atrial (AVR) and 50 double (DVR) valve replacements. RESULTS: The 30-day mortality rate was 4.7% (n = 22); in addition eight patients died more than 30 days after surgery, but during the same hospital stay. Mean follow up was 3.9 years (maximum 11 years and 7 months). Cumulative follow up was 1,750.1 patient-years (pt-yr); follow up was 97.5% complete. Among 39 late deaths, 20 were valve-related (seven cerebral infarction, seven cerebral bleeding, six endocarditis) and four cardiac-related. The overall five-year cumulative survival rate (excluding early mortality) was 90.2 +/- 11.7% (MVR 88.0 +/- 2.5%, AVR 93.1 +/- 2.3%, DVR 93.7 +/- 4.8%). At 10 years, the overall survival rate was 76.4 +/- 7.7%. Valve-related complications included thromboembolism (n = 13, 0.7%/pt-yr), anticoagulation-related hemorrhage (n = 12, 0.7%/pt-yr) and endocarditis (n = 7, 0.4%/pt-yr). Neither mechanical failure nor clinical hemolysis was observed. The overall valve-related event-free rate after five years was 89.3 +/- 2.0% (MVR 89.8 +/- 2.4%, AVR 93.5 +/- 2.6%, DVR 89.4 +/- 5.7%) and after 10 years it was 87.6 +/- 2.6% (MVR 85.4 +/- 3.7%, AVR 93.5 +/- 2.6%, DVR 82.5 +/-10.1%). CONCLUSIONS: These long-term results with the Omnicarbon valve are excellent; especially satisfactory results were achieved in terms of the low rate of thromboembolic complication.     

Fourteen years' experience with the CarboMedics valve in young adults with aortic valve disease

BACKGROUND AND AIM OF THE STUDY: Homografts and the Ross procedure are recommended by many surgeons for aortic valve replacement (AVR) in young adults. The study aim was to monitor patient outcome over a 14-year period after implanting mechanical CarboMedics prosthetic heart valves in young adults with aortic valve disease. METHODS: Between November 1987 and December 2000, 55 patients (42 males, 13 females; median age 33 years; range 15-40 years) each received a CarboMedics valve in the aortic position. All patients were included on a consecutive and non-selected basis. Concomitant surgery was performed in five patients. Anticoagulation was commenced on postoperative day 1. After discharge, patients were followed up by their cardiologist or general practitioner using questionnaires and telephone calls. Actuarial estimates of survival and freedom from morbid events were calculated using the Kaplan-Meier method. RESULTS: No patient died during surgery. Complete follow up data were available for all patients; total follow up was 404 patient-years (pt-yr). The 30-day mortality rate was zero. Actuarial survival at 14 years was 90 +/- 4.9%, and actuarial freedom from all valve-related events 92 +/- 3.7%. No valve thrombosis or major bleeding events were identified. Linearized rates per 100 pt-yr were: embolism 0.25; paravalvular leakage 0.25; prosthetic endocarditis 0.25; and reoperation 0.50. There was no hemolysis, prosthetic valve dysfunction, or structural deterioration. CONCLUSION: Over a 14-year period, implantation of the CarboMedics prosthetic heart valve has proven to be an excellent solution for AVR in young adults with aortic valve disease.     

Long-term results with St. Jude Medical and CarboMedics prosthetic heart valves

BACKGROUND AND AIM OF THE STUDY: The clinical evaluation and comparison of St. Jude Medical (SJM) and CarboMedics (CM) prosthetic heart valves implanted between 1988 and 1997 is presented. METHODS: In total, 648 SJM valves were implanted in 641 patients, and 601 CM valves in 591 patients. There were 684 mitral valve replacements, 256 aortic valve replacements, 252 mitral and aortic (double) valve replacements, 16 triple valve replacements, and 41 other tricuspid-related valve replacements. Total follow up was 98%. The overall incidence of valve-related events was compared before and after establishment of a 'valve clinic' in 1993. RESULTS: The overall hospital mortality was 3.4%; late mortality was 8.2%. The five- and ten-year survival for all patients was 92.1% and 86.2%, respectively. There were 31 episodes of thromboembolism in 27 patients (including valve thrombosis in three), 21 episodes of bleeding events in 20 patients, and 18 re-replacements of implanted valves. No structural valve deterioration was observed. Freedom from thromboembolism was 97.8% at five years and 96.3% at ten years; freedom from bleeding episodes was 98.1% and 97.6%, respectively. In terms of hospital and late mortality, and incidence of thromboembolism, hemorrhagic episodes and structural valve failure, no statistically significant differences were found between the SJM and CarboMedics patient groups. Freedom from thromboembolism was 96.7% at five years before initiation of an intensive follow up program, and 99.0% thereafter (p = 0.031). In contrast, freedom from bleeding episodes fell from 99.3% to 96.1% during the same time period (p = 0.0004). CONCLUSION: Both the SJM and CM prosthetic heart valves performed well in our study, and no discernible differences in clinical performance of the two valves were detected. The intensive follow up program resulted in a reduced incidence of thromboembolism, but an increased number of bleeding complications. An optimum anticoagulation regimen to manage these two conflicting problems has yet to be elucidated.     

Single-center experience with the On-X prosthetic heart valve between 1996 and 2005

BACKGROUND AND AIM OF THE STUDY: Herein are presented long-term results for the On-X mechanical heart valve. All On-X heart valve recipients since the first implantation worldwide at the University of Bochum in September 1996 were followed retrospectively; the present authors' single-center experience over a period of almost 10 years is reported. METHODS: A total of 428 patients (255 males, 173 females; mean age 62.7 years) underwent either aortic valve replacement (AVR; n = 264) or mitral valve replacement (MVR; n = 164) using the On-X prosthesis. Preoperatively, 329 patients (76.8%) were in NYHA class III or IV. Approximately 5% of AVR and 23% of MVR patients had undergone previous cardiac surgery. Concomitant surgery was performed in 189 patients (44.2%). The mean follow up was 3.9 years, and cumulative follow up 1,625 patient-years (pt-yr); the overall follow up rate was 98.7%. RESULTS: Early mortality (< or = 30 days) was 3.7% after AVR and 14.0% after MVR, with valve-related mortality rates of 0.4% and 1.2%, respectively. At autopsy (n = 12) all implants were intact. Freedom from valve-related death at nine years was 85.0 +/- 3.9% after AVR and 87.6 +/- 3.2% after MVR. The overall survival rate was 67.9 +/- 4.3% after AVR and 52.7 +/- 8.1% after MVR. The linearized rate of thromboembolism for AVR and MVR was 1.49%/pt-yr and 1.61%/pt-yr; of thrombosis 0%/pt-yr and 0.35%/pt-yr; of hemorrhage 0.93%/pt-yr and 1.43%/pt-yr; of endocarditis 0.37%/pt-yr and 0.17%/pt-yr; of non-structural failure 0.18%/pt-yr and 1.43%/pt-yr; and of reoperation 0.28%/pt-yr and 0.53%/pt-yr. There were no cases of structural valve failure. CONCLUSION: After almost one decade of clinical experience in a single center, the On-X heart valve continues to be reliable and effective.     

Hemodynamic evaluation of the CarboMedics prosthetic heart valve in the aortic position: comparison of noninvasive and invasive techniques.

Seventy-three patients with a CarboMedics aortic bileaflet valve prosthesis were examined by Doppler ultrasonography, and 27 of them were also assessed by transseptal catheterization. The ultrasonic mean systolic gradient was 17.1 +/- 5.6 mm Hg for valve size 19 mm, falling gradually with increasing valve size to 6.8 +/- 2.5 mm Hg for size 27 mm. The catheter mean systolic gradient was consistently smaller than the ultrasonic gradient (4.3 +/- 4.8 mm Hg), but Tobit regression analysis showed a significant association between the two methods. In all patients both methods revealed negligible to small amounts of retrograde leakage, which is assumed to be a normal finding for this valve. The effective flow areas of the valves calculated from the ultrasonic data were similar to the in vitro calculated flow areas. The hemodynamic potential of this valve is therefore completely utilized in vivo. The effective orifice area corrected for body surface area increased with increasing valve size, which demonstrates a moderate valve-patient mismatch.     

Choosing a prosthetic heart valve

Although most of the available prosthetic heart valves function remarkably well, the variety of available designs attests to the inability of any single one to fulfill the requirements of the ideal valve substitute. The mechanical prostheses include the caged-ball, tilting-disc, and bileaflet valves. Tissue valves available in the United States are the Carpentier-Edwards and Hancock porcine heterograph valves. Review of several large comparative studies on valve performance reveals that the overall results with tissue and mechanical valves are about equal at the end of 10 years. The characteristics of each type of valve substitute dictates the selection of one prosthesis in preference to others for a particular patient. Mechanical prostheses are recommended for patients without contraindications for anticoagulants. Tissue valves are reserved for patients over 70 years of age or for patients in whom anticoagulation is contraindicated. Multiple other patient-related factors need to be considered in selecting the appropriate valve, including the psychosocial situation and patient preference.     

The CarboMedics 'Top-Hat' aortic valve prosthesis: short-term results

BACKGROUND AND AIM OF THE STUDY: The CarboMedics 'Top-Hat' aortic valve prosthesis has been specifically designed for supra-annular implantation. The aim of this study was to assess the safety of implantation of this prosthesis by reporting the short-term results of follow up. METHODS: Between May 1993 and May 1998, 128 patients (mean age 62.5 +/- 9.8 years; range: 22-76 years) received a CarboMedics 'Top-Hat' prosthesis at our institution. Among patients, 55% were in NYHA functional classes III or IV, and 54.7% had an isolated aortic valve replacement. Associated procedures were: coronary artery bypass grafting (25.7%), double valve replacement (17.1%), treatment of ascending aortic aneurysm (4.7%) and miscellaneous (5.5%). Follow up was 100% complete; total cumulative follow up was 265 patient-years (pt-yr) (range: 2-60 months). RESULTS: The overall mortality rate was 1.5% (two deaths). The operative mortality rate was 0.8% (one death); this patient died from neurological complications after operation for aortic dissection. The other patient died on postoperative day 40 from a massive cerebral hemorrhage. Four patients presented thromboembolic events; in all cases these were reversible ischemic neurologic deficits. One patient had a nonstructural deterioration (endocarditis) and required reoperation. Freedom from mortality was 98.3% at five years (linearized rate of 0.75%/pt-yr). Freedom from thromboembolism was 63.1% at five years (linearized rate 1.5%/pt-yr). CONCLUSION: Short-term results with the CarboMedics 'Top-Hat' prosthesis were satisfactory, with low rates of morbidity and mortality. As this prosthesis has demonstrated a good reliability to date, we have continued its implantation in our institution, and long-term follow up will be necessary to confirm these good early results.     

Fifteen-year experience with 24 pregnancies associated with prosthetic valve replacements

During the past 15 years, we followed 21 patients with prosthetic heart valves who experienced a total of 24 pregnancies at mean age of 31.3 +/- 3.6 years. The course of these patients and their pregnancies were reviewed to evaluate the problems associated with prosthetic heart valves and anticoagulation. Among the 21 patients, the aortic valve (AV) had been replaced in 10 (12 pregnancies), the mitral valve (MV) in nine (10 pregnancies), AV + MV in one (one pregnancy), and the tricuspid valve (TV) in one (one pregnancy). The implanted prosthetic valves were mechanical type in 16 cases (Bj?rk-Shiley 15, Starr-Edwards 1) and bioprosthetic type in six (Hancock 5, Ionescu-Shiley 1). With the exception of one case of intra-uterine fetal death probably related with warfarin therapy, all the patients with bioprosthetic valves underwent successful deliveries. Anticoagulant therapy was employed for 11 pregnancies; warfarin for 10 and subcutaneous heparin for one. No anticoagulant therapy was performed for 13 pregnancies. Ten of the 21 mothers had atrial fibrillation. Eighteen pregnancies (67%) culminated in uneventful deliveries for both mothers and infants. Three mothers (13%) died of thromboembolic complications; two of cerebrovascular accidents and one of acute heart failure caused by thrombus on the replaced valve. All of them had Bj?rk-Shiley valves. Oral warfarin was administered in one of the three, heparin in one and no anticoagulant in the remaining one. Massive maternal bleeding occurred in two cases (8%). There were three cases (12%) of intra-uterine fetal death which were caused by intracranial hemorrhages.(ABSTRACT TRUNCATED AT 250 WORDS)     

Reoperation for prosthetic heart valve replacement

From 1974 to 1984, 847 heart valve replacement operations were performed with 1005 prosthetic valves. Thirty-nine (4.6%) were reoperations with 43 prosthetic valve replacements (PVR), on 38 patients. Thirty-three patients had received their initial valve replacement in our hospital and 5 elsewhere. Twenty additional cardiac procedures were required, concomitantly with the prosthesis replacement. Twenty-three patients underwent replacement of a mechanical prosthesis (61%) an average of 4.3 years after initial implantation and 15 patients a bioprosthesis (39%) after 2.8 years. Indications for PVR were endocarditis in 15 patients (39%), prosthesis failure in 13 (34%), periprosthetic leak in 7 (18%), thrombosis in 2 (5%), and a left ventricle subannular aneurysm in 1 (3%). Preoperatively 4 patients were in NYHA functional class II (11%), 15 in class III (39%) and 19 in class IV (50%). Six patients died early postoperatively (15.8%) Various risk factors were analyzed. The early mortality rate was 22% for mechanical prosthesis replacement and 7% for bioprosthesis; 11% for aortic position, 13% for mitral position and 50% to 100% for double valve replacement; 23% for non-elective and 6% for elective operations; 10% for patients with only an initial valve replacement and 43% with additional previous valve operations; 18% for active endocarditis, 15% for prosthesis failure, 14% for periprosthetic leak, 0% for thrombosis and 100% for subannular aneurysm; 0% for patients in class II, 7% in class III and 26% in class IV; 6% in patients with an aortic cross-clamp time less than 2 hours and 24% with more; 27% prior to 1981 and 9% during the last 4 years; and finally 50% in patients over the age of 60.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of prosthetic heart valve function by Doppler echocardiography. A decade of experience

Since the first report of the application of Doppler echocardiography in the evaluation of prosthetic heart valves 10 years ago, dozens of studies have reaffirmed the usefulness of this technique in the noninvasive assessment of transvalvular hemodynamics. Most of these studies have established "normal values" for Doppler-determined pressure gradients and valve areas of prosthetic mitral and aortic valves. Although these studies have established the "normal range," they have all emphasized the individual variability in clinically normal functioning valves. Most of these studies have confirmed the extraordinary sensitivity and specificity of Doppler in detecting prosthetic valve dysfunction. The study by Burstow et al further emphasizes the excellent correlation obtained with simultaneous Doppler and catheter transvalvular pressure gradient measurements. The addition of both color flow Doppler techniques and transesophageal echocardiography can only serve to enhance the clinical diagnostic accuracy of this technique. At the present time, Doppler echocardiography is clearly the procedure of choice for the evaluation of the patient with suspected prosthetic heart valve dysfunction.     

Surgical treatment of prosthetic valve thrombosis: ten years' experience

BACKGROUND AND AIM OF THE STUDY: Prosthetic valve thrombosis (PVT) is a rare, but serious, complication of heart valve replacement with a mechanical substitute. Herein is presented the authors' surgical experience of 18 patients with PVT. METHODS: A total of 1,584 heart valve operations was performed in 1,365 patients at the authors' institution between June 1995 and September 2005. Surgical reports of prosthetic valve reoperations over the same period were screened. Preoperative, operative and postoperative data were collected from the patient cohorts. RESULTS: Since July 1997, 18 patients (12 females, six males; mean age 35.9 +/- 11.3 years; range: 22-60 years) presented with PVT. The subtherapeutic anticoagulation level was the major etiologic factor involved in the pathogenesis of PVT. Thrombosis occurred in the mitral position in 14 patients (78%), and in the aortic position in four (22%). All mechanical valves implanted were bileaflet (1,097 St. Jude Medical, 324 CarboMedics, and 163 Sorin). The mean duration from valve replacement to PVT was 48.3 +/- 15.4 months. The majority of patients presented with poor functional status (56% in NYHA class IV) and poor anticoagulation (INR < or = 2 in 72% of cases). Valve re-replacement was performed for all patients. The 30-day mortality was 16.7%. CONCLUSION: PVT is a potentially fatal complication of heart valve replacement. These acceptable results suggest that early surgical intervention might be a safe and effective treatment of choice in patients with PVT. Patients with mechanical valve prostheses should be informed adequately about the need for, and the importance of, an effective anticoagulation regimen.