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Objective Although the results of aortic valve replacement are well documented for industrialized countries, the outcome in patients with rheumatic aortic valve disease in low- to middle-income countries is less well explored. The aim of this study was to determine the long-term survival and clinical outcomes after isolated aortic valve replacement in patients with rheumatic heart disease in a Sub-Saharan country where follow-up of indigent patients is often challenging. Methods A retrospective review of 969 aortic valve replacements performed between 2003 and 2013 was conducted at Cape Town's Groote Schuur Hospital. Patients who underwent concomitant procedures (n = 664) or had nonrheumatic valve pathology (n = 185) were excluded. The mean age of the rheumatic cohort (n = 121) was 43.1 ± 11.6 years with a mean follow-up period of 6.14 ± 3.44 years. The primary end points were survival and valve-related complications. Results A 15% cardiac- or valve-related 10-year mortality after receiving a mechanical prosthesis corresponded with a significantly higher mortality rate than that of a matched population. Overall cumulative survival at 1, 5, and 10 years was 93.5% (87.0-96.9), 86.4% (78.4-91.8), and 78.1% (67.5-86.0), respectively, and the corresponding cumulative freedom from combined thromboembolism and bleeding was 94.4% (88.2-97.5), 87.4% (79.4-92.5), and 86.1% (77.9-91.6), respectively. Conclusions In low- to middle-income countries, with their unique mix of indigent and “First World” patients, rheumatic heart disease still accounts for a significant proportion of patients requiring isolated aortic valve replacement. Although mechanical prostheses are often selected in these young adults, survival remains suboptimal. Major bleeding and thromboembolic events account for the majority (77%) of the reported valve-related complications.

Improved durability and preference to avoid anticoagulation have led to increasing use of bioprostheses in younger patients despite the need for eventual reoperation. Therefore, we compared in-hospital complications, reoperation, and survival after bioprosthetic and mechanical aortic valve replacement.From January 1990 to January 2020, 6143 patients underwent isolated aortic valve replacement at Cleveland Clinic; 637 patients received a mechanical prosthesis and 5506 a bioprosthesis. Propensity matching identified 527 well-matched pairs (83% of possible matches) for comparison of perioperative outcomes. The average age of patients was 54 years in the bioprosthesis group and 55 years in the mechanical prosthesis group. Random Forest machine-learning analysis was performed to compare survival using the entire cohort of 6143 patients.Among matched patients, major in-hospital complications, including stroke, deep sternal wound infection, and reoperation for bleeding, were similar, as was in-hospital mortality (2 in the bioprosthesis group [0.38%] vs 3 in the mechanical prosthesis group [0.57%]; P .9). Patients receiving a bioprosthesis had shorter hospital stays (median 6 vs 7 days, P .0001). Fifty-one patients (32% at 14 years) in the bioprosthesis group and 17 patients in the mechanical prosthesis group (8% at 14 years) underwent reoperation (P [log-rank] .0001); 5-year survival after reoperation was 85% versus 82% (P = .6). Risk-adjusted Random Forest prediction of 18-year survival was 60% in the bioprosthetic group and 58% in the mechanical prosthesis group.Aortic valve bioprostheses are associated with excellent short-term outcomes and 18-year survival similar to that of patients receiving mechanical valves. Reoperation does not adversely affect survival. These results suggest that risk for reoperation alone should not deter the use of bioprostheses in younger patients.

Background We aimed to assess the long-term outcomes of children in whom the aortic valve could be repaired without the use of patch material. We hypothesized that if the aortic valve is of sufficiently good quality to perform repair without patches, a durable repair could be achieved. Methods All children (n = 102) who underwent aortic valve repair without the use of a patch between 1980 and 2016 were reviewed. Results The median patient age at operation was 2 years (interquartile range, 1 month to 9.6 years). There were 25 neonates and 17 infants. There was no operative mortality. Mean overall survival at 10 years was 97.7% ± 0.01% (95% confidence interval, [CI] 91.0%-99.4%). Forty-three patients (42.2%) required 56 aortic valve reoperations, including 24 redo aortic valve repairs, 22 Ross procedures, 8 mechanical aortic valve replacements, and 2 homograft aortic valve replacements. Mean freedom from aortic valve reoperation at 10 years was 57.4% ± 0.06% (95% CI, 44.9%-68.1%), and freedom from aortic valve replacement at 10 years was 74.5% ± 0.05% (95% CI, 63.0%-82.9%) at 10 years. Freedom from aortic valve reoperation at 10 years was 33.1% ± 0.1% (95% CI, 14.5%-53.2%) in neonates and 68.9% ± 0.06% (95% CI, 54.5%-79.6%) in older children (P Conclusions In approximately one-third of children undergoing aortic valve repair, the repair could be achieved without patches. In these children, aortic valve repair was achieved without operative mortality. Infants and older children have low reoperation rates, whereas reoperation rates in neonates are higher. Initial repair allows valve replacement to be delayed to later in childhood, when a more durable result may be achieved.

Time trends in surgical valve selection have not been explored in detail in the era of transcatheter aortic valve replacement (TAVR) in nationally representative data. Herein, we explore valve selection trends in the TAVR era using the Society of Thoracic Surgeons Adult Cardiac Surgery Database.Isolated first-time biological or mechanical aortic valve replacements (AVR) from 2004 to 2016 in the Society of Thoracic Surgeons Adult Cardiac Surgery Database were included. Patient characteristics were examined in the pre-TAVR era (2004-2007) and the post-TAVR era (2008-2016) using the year 2007 as the cut-point. Using a piece-wise regression analysis to model the relationship between time and type of valve used, a change-point analysis was performed to empirically determine the time of change in practice, both overall and in age-specific subgroups (≤60 years and60 years).In total, 214,390 patients underwent isolated primary mechanical or biological AVR from 2004 to 2016. The patients' mean age increased slightly between the 2 eras (67.1 vs 68.6 years, P .001), whereas the proportion of mechanical AVRs decreased (24.8% vs 12.2%, P .001). Piece-wise regression demonstrated that the proportion of mechanical valves decreased over time. An empirically estimated slope change-point was found after the first quarter 2010; from 2004 to 2009, the overall proportion of mechanical valves was decreasing quickly (-2.81%/year, 95% confidence interval [95% CI], -3.03% to -2.60%), compared with 2010 to 2016. The early decline was steeper for younger patients (-4.21%/year, 95% CI, -4.74 to -3.69) compared with older patients (-1.44%/year, 95% CI -1.64 to -1.23).Use of mechanical AVR declined significantly from 2004 to 2016 and was decreasing before the introduction or the approval of TAVR in the United States.

The goal of this study was to examine the long-term survival of patients between the ages of 50 and 65 years who underwent tissue versus mechanical aortic valve replacement (AVR) in a multicenter cohort.A multicenter, retrospective analysis of all AVR patients (n = 9388) from 1991 to 2015 among 7 medical centers reporting to a prospectively maintained clinical registry was conducted. Inclusion criteria were: patients aged 50 to 65 years who underwent isolated AVR. Baseline comorbidities were balanced using inverse probability weighting for a study cohort of 1449 AVRs: 840 tissue and 609 mechanical. The primary end point of the analysis was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation.During the study period, there was a significant shift from mechanical to tissue valves (P .001). There was no significant difference in major in-hospital morbidity, mortality, or length of hospitalization. Also, there was no significant difference in adjusted 15-year survival between mechanical versus tissue valves (hazard ratio, 0.87; 95% confidence interval [CI], 0.67-1.13; P = .29), although tissue valves were associated with a higher risk of reoperation with a cumulative incidence of 19.1% (95% CI, 14.4%-24.3%) versus 3.0% (95% CI, 1.7%-4.9%) for mechanical valves. The reoperative 30-day mortality rate was 2.4% (n = 2) for the series.Among patients 50 to 65 years old who underwent AVR, there was no difference in adjusted long-term survival according to prosthesis type, but tissue valves were associated with a higher risk of reoperation.

ObjectiveWe sought to examine the relationship between the degree of prosthesis–patient mismatch and long-term survival after mechanical aortic valve replacement.MethodsProspectively collected long-term follow-up data from 469 consecutive patients who underwent aortic valve replacement between 1995 and 1998 were reviewed. The indexed effective orifice area was derived from the reference normal values of effective orifice area divided by the patient's body surface area. Outcome was stratified according to the severity of prosthesis–patient mismatch: moderate mismatch was defined as 0.65 to 0.85 cm2/m2 and severe mismatch as less than 0.65 cm2/m2. The Cox proportional-hazards model with propensity score adjustment was used to adjust for the observed differences in baseline characteristics between the mismatch groups.ResultsThe degree of prosthesis–patient mismatch was minimal in 57% of patients, moderate in 39%, and severe in 4%. Predictors of clinically significant mismatch included small aortic valve sizes (19 and 21 mm), obesity, age greater than 65 years, and class III or IV heart failure. During a median follow-up period of approximately 7.9 years, overall survival was 77% in patients with minimal mismatch, 63% in those with moderate mismatch, and only 47% in those with severe mismatch (P < .001). Moderate or severe mismatch was a significant predictor of poorer survival (hazard ratio, 1.6; 95% confidence interval, 1.4–2.3; P < .01), even after adjustment for all significant clinical predictors (ie, propensity score; hazard ratio, 1.2; 95% confidence interval, 1.0–1.5; P = .05).ConclusionsIn a large aortic valve surgery population, prosthesis–patient mismatch occurred in 43% of patients, and those with significant mismatch had worse long-term outcomes than those with minimal mismatch.

There are little recent data on the outcomes of mechanical aortic valve replacement (AVR) in children and young adults with congenital aortic valve disease. We sought to review the survival and associated thromboembolic or bleeding complications after mechanical AVR at a single center.Data were retrospectively collected for 121 patients undergoing prosthetic AVR from 2000 to 2014. Kaplan-Meier estimates and Cox proportional hazards were employed.Median age at AVR was 16 years (interquartile range, 12-22.8 years). The valves implanted were the St Jude valve (St Jude Medical Inc, St Paul, Minn) in 79 patients (62%), the On-X valve (On-X Life Technologies Inc, Austin, Tex) in 45 patients (35%), and CarboMedics (Sorin SpA, Milan, Italy) in 3 patients (2.4%). Median valve size was 23 mm (range, 21-25 mm). There were 5 early deaths (3.9%). Median follow-up was 5 years (range, 1.6-9.2 years; 600 patient-years). There were 14 deaths during follow-up. Survival was 90.6% ± 2.8% at 1 year, 85.4% ± 3.7% at 5 years, and 81.5% ± 4.5% at 10 years. Freedom from aortic valve reoperation was 98% ± 1.4% at 1 and 5 years, 91.5% ± 3.9% at 7 years, and 78.4% ± 6.9% at 10 years and at latest follow-up. Univariable analysis identified younger age, lower weight, and use of a 16-mm CarboMedics valve as predictors of reoperation. Valve sizes of 16 or 17 mm have a significantly higher risk of reoperation compared with larger valves (log-rank test, P .001). At multivariable analysis, only younger age was a significant independent predictor of reoperation (hazard ratio, 0.84; 95% confidence interval, 0.71-0.99; P = .038). All patients were treated with warfarin to a goal international normalized ratio of 2.0 to 3.0. Four patients (3.1%; 0.66% per patient-year) had thromboembolic complications, and 5 patients (3.9%; 0.83% per patient-year) had bleeding events during follow-up.Mechanical AVR in patients with congenital heart disease has excellent short- and midterm outcomes. Younger age was an independent predictor of reoperation.

Objective Aortic prosthesis choice is controversial in young adults because robust comparative outcome data are lacking. We therefore compared mortality and morbidity in young adults after bioprosthetic versus mechanical aortic valve replacement. Methods This was a retrospective analysis of 5111 patients aged 18 to 50 years undergoing primary aortic valve replacement in California and New York State from 1997 to 2006. Median follow-up time was 11.8 years (maximum 18.9 years). The primary endpoint was mortality; secondary endpoints were stroke, bleeding, and reoperation. Propensity score matching yielded 1175 patient pairs. Results Bioprosthetic valves increased from 14% to 47% of aortic valve replacements between 1997 and 2014 ( P P = .20). No interaction was found between age and prosthesis choice on survival (P interaction = 0.16). After bioprosthetic valve replacement, stroke rates were lower (5.4% [95% CI, 3.8%-7.2%] vs 8.1% [95% CI, 6.3%-10.2%], HR 0.62 [95% CI 0.43-0.91]), bleeding rates were lower (4.2% [95% CI, 3.0-5.6%] vs 8.4% [95% CI, 6.6-10.4%], HR 0.48 [95% CI, 0.33-0.69]), but reoperation rates were greater (24.5% [95% CI, 21.3%-27.8%] vs 9.3% [95% CI, 7.2%-11.7%], HR 5.9 [95% CI 3.2-11.0]) at 15 years versus mechanical valve replacement. Conclusions Although lifetime risks are represented incompletely, these findings suggest that in adults aged 18-50 years, bioprostheses are a reasonable alternative to mechanical valves for aortic valve replacement.

Objective: Orientation for optimal systolic performance of tilting disc and bileaflet aortic valves was defined in previous studies. The present study investigates the influence of valve orientation on coronary artery flow in an animal model. Methods: A rotation device holding either a Medtronic Hall tilting disc (n = 4; Medtronic, Inc, Minneapolis, Minn), a St Jude Medical bileaflet (n = 4; St Jude Medical, Inc, St Paul, Minn), or a Medtronic Advantage bileaflet (n = 3) aortic valve was implanted. The device allowed rotation of the valve without reopening the aorta. Flow through the left anterior descending coronary artery was measured preoperatively and at normal versus high cardiac output after weaning from extracorporeal circulation. Measurements were performed at the best and worst hemodynamic position, as defined previously. Results: Coronary flow rates were similar in all animals preoperatively (26 ± 4.1 mL/min). After aortic valve replacement, left anterior descending flow increased significantly to 58.2 ± 10.6 mL/min. Highest flow rates at normal cardiac output were found in the optimum orientation, especially for the Medtronic valves (Medtronic Hall, 64 ± 8.7 mL/min; Medtronic Advantage, 64.6 ± 11.6 mL/min; St Jude Medical, 48.3 ± 10.3 mL/min), whereas the worst position demonstrated significantly lower left anterior descending flow, with no differences among valves (Medtronic Hall, 37.5 ± 1.3 mL/min; St Jude Medical, 35.7 ± 10.7 mL/min; Medtronic Advantage, 39.8 ± 10 mL/min). Left anterior descending artery flow increased significantly with higher cardiac output. Conclusions: Coronary blood flow was significantly influenced by mechanical aortic valve implantation and the orientation of prostheses. For both valve designs, the previously defined optimum orientation with respect to pressure gradients and turbulence demonstrated the highest left anterior descending flow rates. Even in its optimum orientation, the St Jude Medical valve showed significantly lower coronary flow than the other valves. J Thorac Cardiovasc Surg 2002;124:925-32

Objective: We sought to compare outcomes with tissue and St Jude Medical mechanical valves over a 20-year period. Methods: Valve-related events and overall survival were analyzed in 2533 patients 18 years of age or older undergoing initial aortic, mitral, or combined aortic and mitral (double) valve replacement with a tissue valve (Hancock, Carpentier-Edwards porcine, or Carpentier-Edwards pericardial) or a St Jude Medical mechanical valve. Total follow-up was 13,390 patient-years. There were 666 St Jude Medical aortic valve replacements, 723 tissue aortic valve replacements, 513 St Jude Medical mitral valve replacements, 402 tissue mitral valve replacements, 161 St Jude Medical double valve replacements, and 68 tissue double valve replacements. The mean age was 68 ± 13.3 years (St Jude Medical valve, 64.5 ± 12.9; tissue valve, 72.0 ± 12.6). Results: There were no overall differences in survival between tissue and mechanical valves. Multivariable analysis indicated that the type of valve did not affect survival. Analysis by age less than 65 years or 65 years or older and presence or absence of coronary disease revealed similar long-term survival in all subgroups. The risk of hemorrhage was lower in patients receiving tissue aortic valve replacements but was not significantly different in patients receiving mitral valve or double valve replacements. Thromboembolism rates were similar for tissue and mechanical valve recipients. However, reoperation rates were significantly higher in patients receiving both aortic and mitral tissue valves. The reoperation hazard increased progressively with time both in patients receiving aortic and in those receiving mitral tissue valves. Overall valve complications were initially higher with mechanical aortic valves but not with mechanical mitral valves. However, valve complication rates later crossed over, with higher rates in tissue valve recipients after 7 years in patients undergoing mitral valve replacement and 10 years in those undergoing aortic valve replacement. Conclusions: Tissue and mechanical valve recipients have similar survival over 20 years of follow-up. The primary tradeoff is an increased risk of hemorrhage in patients receiving mechanical aortic valve replacements and an increased risk of late reoperation in all patients receiving tissue valve replacements. The risk of tissue valve reoperation increases progressively with time. J Thorac Cardiovasc Surg 2001;122:257-69

Objective: The purpose of this study was to optimize selection criteria of biologic versus mechanical valve prostheses for aortic valve replacement. Methods: Retrospective analysis was performed for 841 patients undergoing isolated, first-time aortic valve replacement with Carpentier-Edwards (n = 429) or St Jude Medical (n = 412) prostheses. Results: Patients with Carpentier-Edwards and St Jude Medical valves had similar characteristics. Ten-year survival was similar in each group (Carpentier-Edwards 54% ± 3% versus St Jude Medical 50% ± 6%; P = .4). Independent predictors of worse survival were older age, renal or lung disease, ejection fraction less than 40%, diabetes, and coronary disease. Carpentier-Edwards versus St Jude Medical prostheses did not affect survival (P = .4). Independent predictors of aortic valve reoperation were younger age and Carpentier-Edwards prosthesis. The linearized rates of thromboembolism were similar, but the linearized rate of hemorrhage was lower with Carpentier-Edwards prostheses (P

High levels of turbulent stresses resulting from disturbed blood flow may cause damage to red blood cells and platelets. The purpose of this study was to evaluate the spatial distribution and temporal development of turbulent stresses downstream of three mechanical aortic valve prostheses in human subjects: the St. Jude Medical, the CarboMedics, and the Staff-Edwards silicone rubber ball. Blood velocity measurements were taken at 17 measuring points in the cross-sectional area of the ascending aorta 5 to 6 cm downstream of the aortic anulus with the use of a perivascular pulsed Doppler ultrasound system. Turbulence analysis was done for each of the 17 measuring points by calculating the radial Reynolds normal stresses within 50 msec overlapping time windows during systole. By coordinating the calculated Reynolds normal stress values for each time window and for all measuring points, computerized two-dimensional color-coded mapping of the turbulent stress distribution during systole was done. For the St. Jude Medical valves the highest Reynolds normal stress (27 to 63 N/m 2 ) were found along the central slit near the vessel walls. The temporal development and spatial distribution of Reynolds normal stresses for the CarboMedics valves were quite similar to those of the St. Jude Medical valves with maximum Reynolds normal stress values ranging from 19 to 72 N/m 2 . The typical Reynolds normal stress distribution for the Staff-Edwards silicone rubber ball valves was asymmetric, revealing the highest Reynolds normal stresses (11 to 56 N/m 2 ) at various locations in the annular region between the ball and the vessel wall. The spatial distribution and temporal development of turbulent stresses downstream of the three investigated mechanical aortic valve prostheses correlated well with the superstructure of the valves. The maximum Reynolds normal stresses for the three valve types were in the same order of magnitude with exposure times sufficient to cause sublethal damage to red blood cells and platelets.

Objective Aortic valve replacement using a tissue valve is controversial for patients younger than 60 years old. The long-term survival in this age group, the expected event rates during long-term follow-up, and valve-related complications are not clearly determined. Methods From January 2000 to December 2009, overall survival, valve-related events, and echocardiographic outcomes were analyzed in all patients younger than 60 years of age, who underwent biologic aortic valve replacement. Patients who received a Perimount Carpentier-Edwards pericardial tissue valve (n = 103) were selected and compared with a propensity matched group of 103 patients who received aortic valve replacement using a mechanical bileaflet valve. The mean follow-up was 33 ± 24 months (range, 2–120), and the mean age at implantation was 50.6 ± 8.8 years (bioprosthesis, 55 ± 8.9 years; mechanical valve, 50 ± 8.6 years; P = .03). Results Survival was significantly reduced in patients after biologic aortic valve replacement (90.3% vs 98%; P = .038). Freedom from all valve-related complications (bioprosthesis, 54.5%; mechanical valve, 51.6%; P = NS) and freedom from reoperation (bioprostheses, 100%; mechanical valve, 98%; P = NS) were comparable in both groups. The average transvalvular mean (11.2 ± 4.2 mm Hg vs 10.5 ± 6.0 mm Hg, P = .05) and peak (19.9 ± 6.7 mm Hg vs 16.7 ± 8.0 mm Hg, P = .03) gradients were greater after biologic aortic valve replacement. Regression of the left ventricular mass index was more pronounced after mechanical valve replacement (118.5 ± 24.9 g/m 2 vs 126.5 ± 38.5 g/m 2 ; P = NS). The echocardiographic patient–prosthesis mismatch was greater at follow-up after biological aortic valve replacement (0.876 ± 0.2 cm 2 /m 2 vs 1.11 ± 0.4 cm 2 /m 2 ; P = .01). Oral anticoagulation was a protective factor for survival among the bioprosthetic valve patients ( P = .024). Conclusions In the present limited cohort of patients younger than 60 years old, biologic aortic valve replacement was associated with reduced mid-term survival compared with survival after mechanical aortic valve replacement. Despite similar valve-related event rates in both groups, the better hemodynamic performance of the mechanical valves and/or protective effect of oral anticoagulation seemed to improve the outcome. The transcatheter valve-in-valve intervention as potential treatment of tissue valve degeneration should not be considered the sole bailout strategy for younger patients because no evidence is available that this would improve the outcome.

FIGURE 1. Felt circular patch is fashioned with diameter slightly larger than that of implanted mechanical valve, and line is drawn along diameter, after which 2 pledgeted Ti-Cron sutures are placed through patch such that all 4 sutures pass through line. The presence of an aortic valvular prosthesis is generally considered to be a relative contraindication to left ventricular assist device (LVAD) implantation. A bypassed, intermittently opening prosthetic valve, whether it is mechanical or biologic, carries a prohibitive risk of thromboembolic complications, despite the use of anticoagulants. To avoid the challenges of long-term mechanical circulatory support in patients with aortic valve prostheses, our group and others have suggested complete surgical closure of the left ventricular outflow tract (LVOT). Although suturing the leaflets together along the lines of coaptation can readily accomplish LVOT closure in patients with biologic aortic prostheses, closing the LVOT in patients with mechanical aortic prostheses generally requires a supravalvular patch. In this brief report, we describe a technique that enables rapid and secure closure of the LVOT in patients with mechanical bileaflet aortic valves. In a recent series of 5 consecutive patientswith aortic valve prostheses or aortic regurgitation, our team closed the LVOT at LVAD implantation, allowing the successful long-term implementation of mechanical circulatory assistance. Primary closure of the lines of leaflet coaptation was possible in 2 patients, 1 with a bovine prosthesis and another with a congenitally bicuspid regurgitant valve. In 2 other patients with significant native valve regurgitation, the leaflet tissue was too delicate to close primarily, so we sutured a pericardial patch around the circumference of the annulus. The fifth patient had a recently placed mechanical aortic valve. In that case,we removed the prosthesis and replaced itwith a pericardial patch, as described by others. Although successful, this last case was technically challenging and time-consuming, leadingus to develop analternative approach toLVOTclosure in patients with mechanical bileaflet aortic valve prostheses.

Objective There is a need for fast sutureless implantation of valve prostheses with a better outcome than that of current valved stents. Methods The suture ring of a St Jude mechanical valve prosthesis (St Jude Medical, Minneapolis, Minn) was replaced by a proprietary non–stent-based attachment ring made of Nitinol memory metal (Endosmart, Stutensee, Germany) and covered with textile. In acute pig experiments, the aortic valve was removed and the device was introduced in a temporary stretched shape and activated by removing constrainers and heating to reach its final attachment shape. Results The devices could be actuated within seconds. Echocardiography showed normal prosthetic valve and heart function. No paradevice leakage was demonstrated by supravalvular angiography. At autopsy, no abnormalities were found in the surrounding structures or valve prostheses. Pulling tests showed the strong adhesive power of Nitinol attachment rings withstanding up to 5 kg of pulling force. Conclusion Nitinol memory metal attachment rings, covered with textile, around suture ring-denuded St Jude mechanical aortic valve prostheses enabled fast and strong sutureless implantation in acute pig experiments. Further studies in chronic animal models and humans are needed to determine long-term safety.

Objectives The aim of this study was to determine long-term survival and clinical outcomes after elective isolated mechanical aortic valve replacement in young adults. Methods A clinical observational study was conducted in a cohort of 450 consecutive adults less than 65 years of age who had undergone elective isolated mechanical aortic valve replacement (AVR) between 1997 and 2006. Patients who had undergone previous cardiac surgery, and those undergoing concomitant procedures or urgent surgery were excluded. Follow-up was 93.3% complete with a mean follow-up of 9.1 ± 3.5 years. The primary end point was survival. Life table analyses were used to determine age- and gender-matched general population survival. Secondary end points were reoperation and valve-related complications. Results Overall actuarial survival at 1, 5, and 10 years was 98% ± 1%, 95% ± 1%, and 87% ± 1%, respectively, which was lower than expected in the age- and gender-matched general population in Quebec. Actuarial freedom from prosthetic valve dysfunction was 99% ± 0.4%, 95% ± 1%, and 91% ± 1% at 1, 5, and 10 years, respectively. Actuarial freedom from valve reintervention was 98% ± 1%, 96% ± 1%, and 94% ± 1% at 1, 5 and 10 years, respectively. Actuarial survival free from reoperation at 10 years was 82% ± 2%. Actuarial freedom from major hemorrhage was 98% ± 1%, 96% ± 1%, and 90% ± 2% at 1, 5, and 10 years, respectively. Conclusions In young adults undergoing elective isolated mechanical AVR, survival remains suboptimal compared with an age- and gender-matched general population. Furthermore, there is a low but constant hazard of prosthetic valve reintervention after mechanical AVR.

ObjectiveUnder Food and Drug Administration investigational device exemption, the Prospective Randomized On-X Anticoagulation Clinical Trial (PROACT) has been testing the safety of less aggressive anticoagulation than recommended by the American College of Cardiology/American Heart Association guidelines after implantation of an approved bileaflet mechanical valve.MethodsIn this first limb of the PROACT, patients with elevated risk factors for thromboembolism were randomized at 33 US centers to receive lower dose warfarin (test international normalized ratio [INR], 1.5-2.0) or continue standard warfarin (control INR, 2.0-3.0), 3 months after mechanical aortic valve replacement. The INR was adjusted by home monitoring; all patients received 81 mg aspirin daily. Adverse events were independently adjudicated.ResultsA total of 375 aortic valve replacement patients were randomized into control (n = 190) and test (n = 185) groups from September 2006 to December 2009. The mean age ± standard deviation was 55.2 ± 12.5 years; 79% were men; and 93% were in sinus rhythm preoperatively. Calcific degeneration was present in 67%; active endocarditis was excluded. Concomitant procedures included coronary artery bypass grafting (27%), aortic aneurysm repair (14%), and other (25%). The follow-up duration averaged 3.82 years (755.7 patient-years [pt-yrs] for control; 675.2 pt-yrs for test). The mean INR was 2.50 ± 0.63 for the control and 1.89 ± 0.49 for the test groups (P

Objective: Nitinol attachment rings (devices) used to attach mechanical aortic valve prostheses suturelessly were studied in long-term (90 days) pig experiments. Methods: The aortic valve was removed and replaced by a device around a St Jude Medical mechanical valve prosthesis in 10 surviving pigs. Supravalvular angiography was done at the end of the operation. No coumarin derivates were given. Results: No or minimal aortic regurgitation was confirmed in all surviving pigs at the end of the operation. Total follow-up was 846 days. In 4 pigs, follow-up was shorter than 90 days (28-75 days); the other 6 pigs did reach 90 days' survival or more. Repeat angiography in 4 pigs at the end of follow-up confirmed the unchanged position of the device at the aortic annulus, without aortic regurgitation. At autopsy, in all pigs the devices proved to be well grown in at the annulus, covered with endothelium, and sometimes tissue overgrowth related to not using coumarin derivates. There was no case of para-device leakage, migration, or embolization. No damage to surrounding anatomic structures or prosthetic valves was found. Conclusions: Nitinol attachment rings can be used to replace the aortic valve suturelessly with St Jude Medical mechanical aortic valve prostheses, without para-device leakage, migration, or damage to the surrounding tissues, in long-term pig experiments during a follow-up of 90 days or more. Refraining from anticoagulation in pigs with mechanical valve prostheses can lead to tissue overgrowth of the valve prosthesis. Further studies are needed to determine long-term feasibility of this method in human beings.

Objective This study was undertaken to determine long-term clinical and echocardiographic outcomes after the Konno procedure. Methods Fifty-three patients who underwent the Konno procedure between January 1, 1980, and January 1, 2004, were reviewed. Results Mean age at operation was 19 years (range, 1-65 years). Indications were as follows: complex subaortic or tunnel stenosis in 22 (41%), multilevel left ventricular outflow tract obstruction in 20 (38%), and aortic valve stenosis or hypoplasia in 11 (21%). Before the Konno procedure, 66 operations were performed in 41 (77%) patients. Thirty-three (62%) patients had greater than New York Heart Association class I symptoms preoperatively. A mechanical aortic valve was implanted in 40 (75%), a homograft in 10 (19%), and a xenograft prosthesis in 3 (6%). Mortality at 30 days was 8% (n = 4). Survival at 10 years was 86%. Risk factors for overall mortality were New York Heart Association class (hazard ratio 2.22, P = .04) and longer bypass time (hazard ratio 1.93/hour, P = .04). The cumulative probability of aortic valve reoperation was 19% at 5 years and 39% at 10 years, occurring in 15 patients at a median of 3.8 years. The average left ventricular outflow tract mean gradients were 19 mm Hg at 1 year (n = 9), 13 mm Hg at 1 to 3 years (n = 9), and 13 mm Hg at 3 to 5 years (n = 5). Pulmonary regurgitation was detected in 6 patients. Pulmonary valve replacement was performed in 3 (6%). At the date of last contact, all patients for whom data was available were in New York Heart Association functional class I or II. Conclusion The Konno procedure is effective, allowing both long-term reduction of left ventricular outflow tract obstruction and improvement in functional class. Prosthetic aortic valve and native pulmonary valve complications may necessitate reoperation.

The optimal method of anticoagulation in children with mechanical heart valves is controversial. Between 1975 and 1986, aspirin or aspirin with dipyridamole has been used for anticoagulation in children receiving a mechanical aortic valve at the University of California, San Francisco. Fifty-one patients (ages 1 to 23 years, mean 12.9 years) were treated with aspirin (n = 45) or aspirin with dipyridamole (n = 6) and observed a mean of 36.5 months (range 3 to 100 months). There were four late deaths: two from endocarditis and two from other medical problems, but none related to thrombosis or embolus. Follow-up was accomplished by direct contact with the patient, parent, or referring physician. Two patients (3.9%) were lost to late follow-up. One minor neurologic event occurred perioperatively and resolved spontaneously. There were no postoperative thromboembolic events. Eleven asymptomatic children were recently studied by magnetic resonance imaging or computed axial tomography of the brain and had no evidence of prior silent cerebral thromboembolic defects. There were four patients (5.9%) who had minor hemorrhagic complications: Three patients had nosebleeds and one patient had an upper gastrointestinal hemorrhage. Five patients were changed to warfarin anticoagulation: the patient with upper gastrointestinal hemorrhage and four older patients because of physician preference, all after uncomplicated aspirin therapy. There were no mechanical valve failures, although one patient required reoperation 9 months later for perivalvular leak. All children have remained in normal sinus or paced rhythm during follow-up. These results show that children with mechanical aortic valves in normal sinus rhythm can be safely treated with aspirin (or aspirin with dipyridamole) with little risk of thromboembolic events, valve thrombosis, or valve failure. Hemorrhagic complications resulting from aspirin are minor and easily treated.

See related articles on pages 313 and 337. C omprehensive 2-dimensional Doppler echocardiography is the modality of choice for anatomic and hemodynamic evaluation of prosthetic heart valves. However, Doppler hemodynamic assessment of mechanical aortic valve prostheses, especially bileaflet valves, requires consideration of the physical principles governing transvalvular flows. In this issue De Carlo and colleagues have evaluated the hemodynamic performance of the small-sized, bileaflet, Sorin Bicarbon aortic valve prosthesis (SBP) using Doppler peak and mean gradients and calculated effective orifice area (EoA) and effective orifice area index (EoAi). They have shown that these parameters are comparable with those of other small bileaflet mechanical valves in the aortic position and that there is significant regression in left ventricular hypertrophy (LVH). Because these data provide references for small SBP valves in the aortic position, it is relevant to ask the question of how best to evaluate aortic mechanical valves by means of Doppler echocardiography. To answer this question, it is important to understand the many physical principles that govern transvalvular flow dynamics and the problems and pitfalls associated with any single parameter. Routine echocardiographic evaluations of transvalvular gradients are done by using a simplification of the modified Bernoulli equation as follows: PG 1/2 V, where PG is the pressure gradient, is the density of blood, and V is the Doppler transvalvular velocity. Because 1/2 is approximately 4 for blood, the formula is simplified as follows: PG 4V.

Objective Surgical aortic valvotomy has a long history of providing excellent palliation for aortic stenosis in infancy and childhood. The fate of aortic valve repairs for dominant aortic regurgitation in this same age group is considerably less clear. Methods From 1990 to 2000, a total of 21 patients underwent aortic valve repair for aortic regurgitation at our institution. Seventeen patients were younger than 17 years at the time of repair (3-17 years, mean 8.1 ± 3.7 years). Of these 17 children, 6 (35%) had bicuspid valves and 11 (65%) had tricuspid valves. Type of repair varied with valve type, but repair generally consisted of commissure resuspension, partial commissure closure, triangular resection of redundant leaflets, or some combination. Results There were no deaths. Follow-up ranged from 1 to 11 years (mean 5.3 ± 2.4 years). At present 3 of 17 (17.6%) have mild aortic regurgitation according to echocardiography and 6 (35.2%) have moderate aortic regurgitation. In 8 of 17 cases (47.1%) the repair clearly failed, requiring reoperation from 0.5 to 73 months after the original operation (mean 18.9 months). Reoperation consisted of 6 Ross procedures and 2 mechanical aortic valve replacements. There were no deaths at the secondary operation. Conclusion Aortic valve repair in children with a dominant feature of aortic insufficiency tended to fail progressively and at a high rate. Leaflet thickening was associated with higher risk of repair failure in this series. The threshold for aortic valve replacement should remain low.

OBJECTIVE: Cerebral microembolization is a well-recognized phenomenon after cardiac valve replacement, but the relative proportion of solid and gaseous emboli is uncertain. Particulate microemboli are thought to be the most damaging. With the use of multifrequency transcranial Doppler ultrasound, we compared the number and nature of microemboli in recipients of biologic and mechanical aortic valve prostheses. METHODS: The middle cerebral arteries of 60 patients were monitored bilaterally with a new-generation transcranial Doppler ultrasound (Embo-Dop, DWL Elektronische Systeme GmbH, Singen, Germany) that rejects artefacts online and automatically discriminates between solid and gaseous microemboli. All recordings were performed during a 30-minute period 1 day before and at a mean of 5 days and 3 months after isolated aortic valve replacement with a biologic (30, group B) or mechanical (30, group M) prosthesis. RESULTS: The patients in group B were older, with a mean age of 70.6 +/- 9.7 years versus 55.4 +/- 9.4 years (P < .005) in the patients in group M. Biologic prosthesis recipients were all taking aspirin (no warfarin); patients with mechanical valves were well anticoagulated with warfarin both 5 days and 3 months after surgery. None of the patients had solid microemboli preoperatively. Five days postoperatively, the absolute number of cerebral microemboli was 145 and 594 for total microemboli (P = .001) and 41 and 182 for solid microemboli (P = .002) in groups B and M, respectively. At 3 months, the absolute number was 65 and 608 for total microemboli (P < .001) and 10 and 188 for solid microemboli (P < .001) in groups B and M, respectively. Solid microemboli accounted for 16% of the total microembolic load in group B compared with 31% in group M (P = .05) at 3 months. CONCLUSIONS: Solid cerebral microemboli represent approximately one third of the total cerebral microembolic load after mechanical aortic valve replacement and are detectable in the majority of such patients both 5 days and 3 months after surgery. The neurofunctional consequences of this phenomenon should be carefully assessed.