The effect of treatment timing on repeat revascularization in patients with stable ischemic heart disease.

Objectives: In patients with stable ischemic heart disease, there is no evidence for the effect of revascularization treatment timing on the need for repeat procedures. We aimed to determine if repeat revascularizations differed among patients who received coronary artery bypass graft surgery after the time recommended by physicians compared with those who had timely percutaneous coronary intervention. Methods: We identified 25,520 British Columbia residents 60 years or older who underwent first-time nonemergency revascularization for angiographically proven, stable left main or multivessel ischemic heart disease between January 1, 2001, and December 31, 2016. We estimated unadjusted and adjusted cumulative incidence functions for repeat revascularization, in the presence of death as a competing risk, after index revascularization or last staged percutaneous coronary intervention for patients undergoing delayed coronary artery bypass grafting compared with timely percutaneous coronary intervention. Results: After adjustment with inverse probability of treatment weights, at 3 years, patients who underwent delayed coronary artery bypass grafting had a statistically significant lower cumulative incidence of a repeat revascularization compared with patients who received timely percutaneous coronary intervention (4.84% delayed coronary artery bypass grafting, 12.32% timely percutaneous coronary intervention; subdistribution hazard ratio, 0.16, 95% CI, 0.04-0.65). Conclusions: Patients who undergo delayed coronary artery bypass grafting have a lower cumulative incidence of repeat revascularization than patients who undergo timely percutaneous coronary intervention. Patients who want to wait to receive coronary artery bypass grafting will see the benefit of lower repeat revascularization over percutaneous coronary intervention unaffected by a delay in treatment.

Considerations for prostheses choice in multiple valve surgery.

OBJECTIVES: The prosthesis type for multiple valve surgery (replacement of two or more diseased native or prosthetic valves, replacement of two diseased valves with repair/reconstruction of a third, or replacement of a single diseased valve with repair/reconstruction of a second valve) remains inadequately evaluated. The clinical performance of multiple valve surgery with bioprostheses (BP) and mechanical prostheses (MP) was assessed to compare patient survival and composites of valve-related complications. METHODS: Between 1975 and 2000, 1245 patients had multiple valve surgery (BP 785, mean age 62.0 ± 14.7 years; and MP 460, mean age 56.9 ± 12.9 years). There were 1712 procedures performed [BP 969(56.6%) and MP 743(43.4%). Concomitant coronary artery bypass (conCABG) was BP 206(21.3%) and MP 105(14.1%) (p = 0.0002). The cumulative follow-up was BP 5131 years and MP 3364 years. Independent predictors were determined for mortality, valve-related complications and composites of complications. RESULTS: Unadjusted patient survival at 12 years was BP 52.1 ± 2.1% and MP 54.8 ± 4.6% (p = 0.1127), while the age adjusted survival was BP 48.7 ± 2.3% and MP 54.4 ± 5.0%. The predictors of overall mortality were age [Hazard Ratio (HR) 1.051, p < 0.0001], previous valve (HR 1.366, p = 0.028) and conCABG (HR 1.27, p = 0.021). The actual freedom from valve-related mortality at 12 years was BP 85.6 ± 1.6% and MP 91.0 ± 1.6% (actuarial p = 0.0167). The predictors of valve-related mortality were valve type (BP > MP) (2.61, p = 0.001), age (HR 1.032, p = 0.0005) and previous valve (HR 12.61, p < 0.0001). The actual freedom from valve-related reoperation at 12 years was BP 60.8 ± 1.9% and MP85.6 ± 2.1% (actuarial p < 0.001). The predictors of valve-related reoperation were valve type (MP > BP) (HR 0.32, p < 0.0001), age (HR 0.99, p = 0.0001) and previous valve (HR 1.38, p = 0.008) CONCLUSIONS: Overall survival (age adjusted) is differentiated by valve type over 10 and 12 years and valve-related mortality and valve-related reoperation favours the use of mechanical prostheses, overall for multiple valve surgery.

Cardiac surgeons' concerns, perceptions, and responses during the COVID-19 pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had an unprecedented impact on health care and cardiac surgery. We report cardiac surgeons' concerns, perceptions, and responses during the COVID-19 pandemic. METHODS: A detailed survey was sent to recruit participating adult cardiac surgery centers in North America. Data regarding cardiac surgeons' perceptions and changes in practice were analyzed. RESULTS: Our study comprises 67 institutions with diverse geographic distribution across North America. Nurses were most likely to be redeployed (88%), followed by advanced care practitioners (69%), trainees (28%), and surgeons (25%). Examining surgeon concerns in regard to COVID-19, they were most worried with exposing their family to COVID-19 (81%), followed by contracting COVID-19 (68%), running out of personal protective equipment (PPE) (28%), and hospital resources (28%). In terms of PPE conservation strategies among users of N95 respirators, nearly half were recycling via decontamination with ultraviolet light (49%), followed by sterilization with heat (13%) and at home or with other modalities (13%). Reuse of N95 respirators for 1 day (22%), 1 week (21%) or 1 month (6%) was reported. There were differences in adoption of methods to conserve N95 respirators based on institutional pandemic phase and COVID-19 burden, with higher COVID-19 burden institutions more likely to resort to PPE conservation strategies. CONCLUSIONS: The present study demonstrates the impact of COVID-19 on North American cardiac surgeons. Our study should stimulate further discussions to identify optimal solutions to improve workforce preparedness for subsequent surges, as well as facilitate the navigation of future healthcare crises.

Long-Term Outcomes of the Mosaic Bioprosthesis.

BACKGROUND: The Mosaic bioprosthesis is a third-generation stented porcine bioprosthesis. This study was performed to evaluate long-term survival and durability associated with this device. METHODS: A total of 1,029 patients (797 aortic valve replacements, 232 mitral valve replacements) previously enrolled at 6 centers as part of the original regulatory study were included. We evaluated freedom from death, valve-related reoperation, and explant due to structural valve deterioration (SVD), and compared these outcomes by age (<60 and ≥60 years) at the time of implant. RESULTS: Cumulative follow-up was 7021.2 patient-years in the aortic cohort and 1969.5 patient-years in the mitral cohort. Mean age was 69.5 ± 8.6 and 67.9 ± 10.5 years; 66% and 48% were male, respectively. In the aortic cohort at 17 years, freedom from death was 54.0% in patients younger than 60 years and 24.0% in patients aged 60 years and older (p < 0.01); freedom from reoperation was 36.4% and 81.2%, respectively (p < 0.01); and freedom from explant due to SVD was 47.5% and 89.1% (p < 0.01). At 16 years in the mitral cohort, freedom from death was 67.6% and 20.6% (p < 0.01); freedom from reoperation was 51.3% versus 77.9% (p = 0.04); and freedom from explant due to SVD was 65.2% versus 83.8% (p = 0.23). CONCLUSIONS: This study demonstrates acceptable long-term rates of death, reoperation, and explant due to SVD with the Mosaic bioprosthesis implanted in either the aortic or mitral position. Freedom from explant due to SVD was lower in patients younger than 60 years in the aortic cohort at 17 years, but it was not significantly different between patients younger than 60 years or 60 years and older in the mitral cohort at 16 years.

Long-term Outcomes of Multiple Arterial Coronary Artery Bypass Grafting: A Population-Based Study of Patients in British Columbia, Canada.

Importance: Although the long-term survival advantage of multiple arterial grafting (MAG) vs the standard use of left internal thoracic artery (LITA) supplemented by saphenous vein grafts (LITA+SVG) has been demonstrated in several observational studies, to our knowledge its safety and other long-term clinical benefits in a large, population-based cohort are unknown. Objective: To compare the safety and long-term outcomes of MAG vs LITA+SVG among overall and selected subgroups of patients. Design, Setting, and Participants: In this population-based observational study, we included 20 076 adult patients with triple-vessel or left-main disease who underwent primary isolated coronary artery bypass grafting (MAG, n = 5580; LITA+SVG, n = 14 496) in the province of British Columbia, Canada, from January 2000 to December 2014, with follow-up to December 2015. We performed propensity-score analyses by weighting and matching and multivariable Cox regression to minimize treatment selection bias. Exposures: Multiple arterial grafting or LITA+SVG. Main Outcomes and Measures: Mortality, repeated revascularization, myocardial infarction, heart failure, and stroke. Results: Of 5580 participants who underwent MAG, 586 (11%) were women and the mean (SD) age was 60 (8.7) years. Of 14 496 participants who underwent LITA+SVG, 2803 (19%) were women and the mean (SD) age was 68 (8.9) years. The median (interquartile range) follow-up time was 9.1 (5.1-12.6) years and 8.1 (4.5-11.7) years for the groups receiving MAG and LITA+SVG, respectively. Compared with LITA+SVG, MAG was associated with reduced mortality rates (hazard ratio [HR], 0.79; 95% CI, 0.72-0.87) and repeated revascularization rates (HR, 0.74; 95% CI, 0.66-0.84) in 15-year follow-up and reduced incidences of myocardial infarction (HR, 0.63; 95% CI, 0.47-0.85) and heart failure (HR, 0.79; 95% CI, 0.64-0.98) in 7-year follow-up. The long-term benefits were coherent by all 3 statistical methods and persisted among patient subgroups with diabetes, obesity, moderately impaired ejection fraction, chronic obstructive pulmonary disease, peripheral vascular disease, or renal disease. Multiple arterial grafting was not associated with increased morbidity or mortality rates at 30 days overall or within patient subgroups. Conclusions and Relevance: Compared with LITA+SVG, MAG is associated with reduced mortality, repeated revascularization, myocardial infarction, and heart failure among patients with multivessel disease who are undergoing coronary artery bypass grafting without increased mortality or other adverse events at 30 days. The long-term benefits consistently observed across multiple outcomes and subgroups support the consideration of MAG for a broader spectrum of patients who are undergoing coronary artery bypass grafting in routine practice.

Simulation of Anastomosis in Coronary Artery Bypass Surgery.

Developing cardiac surgical skills and experience takes years of practice. Cardiac trainees need to develop technical proficiency in order to enhance quality of care and patient safety. Simulation-based models are common resources for teaching procedural skills in both undergraduate and postgraduate medical education. Suitable and accessible educational platforms can play a progressively important role in the training process for young surgeons in the area of cardiac surgery. Coronary artery bypass graft (CABG) surgery consists of a wide range of pathologic anatomies and surgical techniques. In this paper we introduce a novel, synthetic, biomimetic platform that allows for the realistic practice of the CABG surgery. The prototype uses a polyvinyl alcohol hydrogel which has been designed to mimic the geometric properties of vasculature. The proposed models look and feel like human tissue and possess somewhat consistent mechanical properties. In this study, we apply the platform to simulate a case of autogenous saphenous vein bypass grafting of a patient. An autogenous saphenous vein graft is placed from the aorta to the left anterior descending coronary artery. The standard procedures of the coronary artery bypass surgery were successfully simulated. Using the proposed technology, other complicated surgeries such as end to end, side to end, and sequential anastomoses can be simulated such that these models lend themselves very well to various types of anastomoses.

The occurrence of adverse events in relation to time after registration for coronary artery bypass surgery: a population-based observational study.

BACKGROUND: Our objective was to evaluate the effect of delays on adverse events while waiting for coronary artery bypass grafting (CABG). METHODS: An observational study that prospectively followed patients from registration on a wait list to removal for planned surgery, death while waiting, or unplanned emergency surgery. The population-based registry provided data on 12,030 patients with a record of registration on a wait list for first-time isolated CABG surgery between 1992 and 2005. RESULTS: In total, 104 patients died and 382 patients underwent an emergency surgery before planned CABG. The death rate was 0.5 per 1000 patient-weeks in the semiurgent group and 0.6 per 1000 patient-weeks the nonurgent group, adjusted OR = 1.07 (95% confidence interval [CI] 0.69-1.65). The emergency surgery rate of 1.2 per 1000 patient-weeks in the nonurgent group was lower compared to 2.1 per 1000 patient-weeks in the semiurgent group (adjusted OR = 0.72, 95% CI 0.54-0.97). However, the nonurgent group had a greater cumulative incidence of preoperative death than the semiurgent group for almost all weeks on the wait list, adjusted OR = 1.92 (95% CI 1.25-2.95). The surgery rate was 1.2 per 1000 patient-weeks in the nonurgent group and 2.1 per 1000 patient-weeks in the semiurgent group, adjusted OR = 0.72 (95% CI 0.54-0.97). The cumulative incidence of emergency surgery before planned CABG was similar in the semiurgent and nonurgent groups, adjusted OR = 0.88, (95% CI 0.64-1.20). CONCLUSION: Despite similar death rates in the semiurgent and nonurgent groups, the longer waiting times in the nonurgent group result in a greater cumulative incidence of death on the wait list compared to that in the semiurgent group. These longer waiting times also offset the lower rate of emergency surgery before planned admission in the nonurgent group so that the cumulative incidence of the emergency surgery was similar in both groups.

Evaluation of supply-side initiatives to improve access to coronary bypass surgery.

BACKGROUND: Guided by the evidence that delaying coronary revascularization may lead to symptom worsening and poorer clinical outcomes, expansion in cardiac surgery capacity has been recommended in Canada. Provincial governments started providing one-time and recurring increases in budgets for additional open heart surgeries to reduce waiting times. We sought to determine whether the year of decision to proceed with non-emergency coronary bypass surgery had an effect on time to surgery. METHODS: Using records from a population-based registry, we studied times between decision to operate and the procedure itself. We estimated changes in the length of time that patients had to wait for non-emergency operation over 14 calendar periods that included several years when supplementary funding was available. We studied waiting times separately for patients who access surgery through a wait list and through direct admission. RESULTS: During two periods when supplementary funding was available, 1998-1999 and 2004-2005, the weekly rate of undergoing surgery from a wait list was, respectively, 50% and 90% higher than in 1996-1997, the period with the longest waiting times. We also observed a reduction in the difference between 90th and 50th percentiles of the waiting-time distributions. Forty percent of patients in the 1998, 1999, 2004 and 2005 cohorts (years when supplementary funding was provided) underwent surgery within 16 to 20 weeks following the median waiting time, while it took between 27 and 37 weeks for the cohorts registered in the years when supplementary funding was not available. Times between decision and surgery were shorter for direct admissions than for wait-listed patients. Among patients who were directly admitted to hospital, time between decision and surgery was longest in 1992-1993 and then has been steadily decreasing through the late nineties. The rate of surgery among these patients was the highest in 1998-1999, and has not changed afterwards, even for years when supplementary funding was provided. CONCLUSIONS: Waiting times for non-emergency coronary bypass surgery shortened after supplementary funding was granted to increase volume of cardiac surgical care in a health system with publicly-funded universal coverage for the procedure. The effect of the supplementary funding was not uniform for patients that access the services through wait lists and through direct admission.

An observational study to evaluate 2 target times for elective coronary bypass surgery.

BACKGROUND: Guidelines for timing of elective bypass surgery were established by expert opinion; yet, there is little evidence to support the recommended target times. OBJECTIVES: To estimate the effect of timing of the procedure on in-hospital mortality by comparing groups of patients that differ in the duration of time between decision to operate and performed procedure. RESEARCH DESIGN: We used a population-based registry to identify patients who underwent surgical coronary revascularization and their hospital discharge summaries to identify in-hospital death. SUBJECTS: We studied 9593 patients who underwent surgical revascularization between 1992 and 2006 after registration on a wait list for first-time isolated coronary artery bypass grafting on an elective basis. MEASURES: The outcome was postoperative in-hospital death. The study variable was the timing of surgery, categorized as short, prolonged, and excessive delays according to the guidelines. METHODS: The probability of in-hospital death in relation to timing of surgery was modeled by logistic regression that included a precalculated risk score for in-hospital death, with weighting observations by inverse propensity scores for the 3 surgery timing groups. RESULTS: In-hospital death among patients with short delays was one third as likely as among those with excessive delays: adjusted odds ratio=0.32 (95% confidence interval 0.20-0.51). The protective effect was smaller and not significant for patients with prolonged delays; odds ratio=0.78 (95% confidence interval, 0.38-1.63). CONCLUSIONS: Our findings suggest a survival benefit from performing elective surgical revascularization within the time frame recommended by the stricter of the 2 guidelines. Our results have implications for health systems that provide universal coverage and that budget the annual number of procedures.

Differences in myocardial PTEN expression and Akt signalling in type 2 diabetic and nondiabetic patients undergoing coronary bypass surgery.

OBJECTIVE: Patients with diabetes experience increased cardiovascular complications after cardiac surgery. Hyperglycaemia predicts increased mortality after myocardial infarction and may influence cardiovascular risk in humans. Impaired prosurvival phosphatase and tensin homologue on chromosome 10 (PTEN)-Akt signalling could be an important feature of the diabetic heart rendering it resistant to preconditioning. This study was designed to evaluate for differences and relationships of myocardial PTEN-Akt-related signalling and baseline glycaemic control marker in type 2 diabetic and nondiabetic patients undergoing coronary artery bypass surgery. METHODS: Right atrial biopsies and coronary sinus blood were obtained from 18 type 2 diabetic and 18 nondiabetic patients intraoperatively. Expression and phosphorylation of Akt, endothelial nitric oxide synthase (eNOS), Bcl-2 and PTEN were evaluated by Western blot. Plasma 15-F(2t) -isoprostane concentrations were evaluated by liquid chromatography-mass spectrometry. RESULTS: PTEN expression and 15-F(2t) -isoprostane concentrations were significantly higher in diabetic patients. Increased fasting blood glucose levels correlated with increased coronary sinus plasma 15-F(2t) -isoprostane concentrations. Increased cardiac 15-F(2t) -isoprostane generation was highly correlated with myocardial PTEN expression. Bcl-2 expression and eNOS phosphorylation were significantly lower in diabetic compared with nondiabetic patients. Akt phosphorylation tended to be lower in diabetic patients; however, this tendency failed to reach statistical significance. CONCLUSION: The current results suggest that prosurvival PTEN-Akt signalling is impaired in the diseased diabetic myocardium. Hyperglycaemia and increased oxidative stress may contribute to this phenomenon. These findings strengthen the understanding of the underlying biologic mechanisms of cardiac injury in diabetic patients, which could facilitate development of new treatments to prevent cardiovascular complications in this high-risk population.

Medtronic Mosaic porcine bioprosthesis: assessment of 12-year performance.

BACKGROUND: The Mosaic porcine bioprosthesis (Medtronic, Inc, Minneapolis, Minn) was approved in 2000 by the US Food and Drug Administration. Clinical performance was evaluated in 6 centers. METHODS: From 1994 to 2000, 797 patients (mean age 69 years) had aortic valve replacement (AVR) and 232 (mean 67 years) had mitral valve replacement (MVR). Concomitant coronary artery bypass grafting was performed with aortic valve replacement (45.4%) and mitral valve replacement (43.5%). Mean follow-ups were 7.5 years for aortic position and 7.3 years for mitral position. RESULTS: Early mortalities were 2.8% for AVR and 3.0% for MVR. Late mortalities were 4.2%/patient-year for AVR and 5.1%/patient-year for MVR. Overall 12-year survivals were 55.8% ± 3.7% for AVR and 43.9% ± 7.4% for MVR. Twelve-year freedoms from valve-related mortality were 87.1% ± 3.1% for AVR and 82.5% ± 7.7% for MVR. Twelve-year freedoms from reoperation were 84.0% ± 3.3% for AVR and 82.5% ± 7.5% for MVR. Freedoms from structural valve deterioration (SVD) by explant reoperation at 12 years for AVR were 93.3% ± 2.6% for patients at least 60 years old and 75.9% ± 9.3% for patients younger than 60 years. Freedoms from SVD by explant reoperation at 10 years for MVR were 95.3% ± 7.8% for patients at least 70 years old and 84.0% ± 9.3% for patients younger than 70 years. Hemodynamic performance data at 1 year for AVR (sizes 21-27 mm) were mean systolic gradient range 13.7 ± 4.8 to 10.3 ± 3.2 mm Hg and effective orifice area range 1.5 ± 0.3 to 2.5 ± 0.4 cm(2). For MVR (sizes 25-31 mm), data were mean diastolic gradient range 6.7 ± 1.7 to 3.7 ± 0.9 mm Hg and effective orifice area range 1.9 ± 0.3 to 2.4 ± 0.6 cm(2). CONCLUSIONS: Overall performance of Mosaic porcine bioprosthesis to 12 years is satisfactory. Freedoms from SVD by explant reoperation were most satisfactory for aortic position in patients at least 60 years old and mitral position in patients at least 70 years old. Overall actuarial freedom from SVD by explant reoperation is encouraging for patients with MVR.

St Jude Medical Epic porcine bioprosthesis: results of the regulatory evaluation.

BACKGROUND: The St Jude Medical Epic heart valve (St Jude Medical, Inc, St Paul, Minn) is a tricomposite glutaraldehyde-preserved porcine bioprosthesis. The St Jude Medical Biocor porcine bioprosthesis is the precursor valve to the St Jude Medical Epic valve. The Epic valve is identical to the Biocor valve except that it is treated with Linx AC ethanol-based calcium mitigation therapy. METHODS: The St Jude Medical Epic valve was implanted in 761 patients (mean age 73.9 ± 9.2 years) between 2003 and 2006 in the US Food and Drug Administration regulatory study in 22 investigational centers. The position distribution was 557 aortic valve replacements, 175 mitral valve replacements, and 29 double valve replacements. Concomitant coronary artery bypass grafting was performed in 50.8% of patients undergoing aortic valve replacement and 36.6% of those undergoing mitral valve replacement. RESULTS: The early mortality was 3.6% in aortic and 2.3% in mitral valve replacement. The follow-up was 1675.5 patient-years with a mean of 2.2 ± 1.2 years/patient. Late mortality was 5.2%/patient-year in aortic and 6.6%/patient-year in mitral valve replacement. The late major thromboembolism rate was 0.98%/patient-year for aortic and 2.6%/patient-year for mitral valve replacement. There were 19 reoperations, including 2 for structural valve deterioration, 1 for thrombosis, 9 for nonstructural dysfunction, and 7 for prosthetic valve endocarditis. The actuarial freedom from reoperation owing to structural valve deterioration for aortic valve replacement at 4 years for age 60 years or less was 93.3% ± 6.4%; for ages 61 to 70 years, 98.1% ± 1.9%; and for older than 70 years, 100% (P = .0006 > 70 vs ≤ 60 years). There were no events of structural deterioration with mitral valve replacement. The actuarial freedom from major thromboembolism for all patients at 4 years was 93.6% ± 1.0%. The 2 cases of structural valve deterioration occurred in aortic valves that became perforated without calcification causing aortic regurgitation. CONCLUSIONS: The performance of the St Jude Medical Epic porcine bioprosthesis is satisfactory at 4 years for both aortic and mitral valve replacement. This study establishes the early clinical performance including durability of this porcine bioprosthesis.

Right-sided endocarditis secondary to a peritoneovenous shunt.

A 51-year-old woman with a peritoneovenous shunt for refractory ascites presented with three months of increasing fatigue, exertional dyspnea, night sweats and positive blood cultures. Imaging revealed multiple pulmonary emboli. Transthoracic  chocardiography demonstrated moderate tricuspid regurgitation and a large pedunculated right atrial mass attached to the interatrial septum. The echocardiographic appearance remained unchanged after one month of antibiotic therapy and  nticoagulation. Intraoperatively, the mass was easily excised and the grossly abnormal tricuspid valve replaced. Pathology revealed endocarditis with multiple bacterial colonies, and fibromyxoid changes consistent with postinflammatory valve disease.

Influence of the On-X mechanical prosthesis on intermediate-term major thromboembolism and hemorrhage: a prospective multicenter study.

OBJECTIVES: Long-term thromboembolic and hemorrhagic outcomes after mechanical valve replacement have been well described; however, few studies have described these outcomes after valve replacement with the On-X mechanical prosthesis (On-X Life Technologies, Inc, Austin, Tex). METHODS: Between 2003 and 2008, 737 patients underwent either aortic valve replacement (n = 400), mitral valve replacement (n = 282), or double-valve replacement (n = 55). Longitudinal performance, freedom evaluation, and risk analysis were assessed with regard to major thromboembolism and hemorrhage. Risk modeling was performed with 16 variables inclusive of age, atrial fibrillation, concomitant coronary artery bypass grafting, New York Heart Association class, and ventricular dysfunction. RESULTS: Early mortality was 2.5% (n = 10) for aortic valve replacement and 3.2% (n = 9) for mitral valve replacement. Late mortality for aortic valve replacement was 4.8% per patient-year and 6.0% per patient-year for mitral valve replacement. Five-year freedom from major thromboembolism was 96.5% ± 1.2% for aortic valve replacement and 97.7% ± 0.9% for mitral valve replacement. Five-year freedom from hemorrhage was 93.6% ± 1.8% for aortic valve replacement and 95.7% ± 1.5% for mitral valve replacement. Concomitant coronary artery bypass grafting was predictive of major thromboembolism after aortic valve replacement (hazard ratio, 5.3; P = .02) and antithrombotic hemorrhage after mitral valve replacement (hazard ratio, 4.7; P = .03). No other independent predictors of major thromboembolism or hemorrhage were identified. One thrombosed mitral prosthesis was observed after deliberate discontinuation of anticoagulation. The major thromboembolic events occurred with variation of international normalized ratio levels inclusive of subtherapeutic levels. The majority of hemorrhagic events occurred with high international normalized ratio levels. CONCLUSIONS: The On-X mechanical prosthesis provides favorable intermediate-term results with regard to major thromboembolism and hemorrhage.

Effect of prosthesis-patient mismatch on long-term survival with aortic valve replacement: assessment to 15 years.

BACKGROUND: The effect of prosthesis-patient mismatch on long-term survival after aortic valve replacement has received considerable attention but there remains controversy. This study was performed to determine the predictors of mortality after aortic valve replacement and influence of prosthesis-patient mismatch on survival. METHODS: Contemporary mechanical prostheses and bioprostheses were implanted in 3,343 patients with aortic valve replacement between 1982 and 2003. The mean age was 68.06 +/- 11.20 years (median 70.06; range, 19 to 94), and the mean follow-up was 6.18 +/- 4.96 years, for a total of 20,666 years of follow-up. Prosthesis-patient mismatch was classified by effective orifice area index categories: normal (> 0.85 cm(2)/m(2)), 1,547 (46.3%); mild-to-moderate (> 0.65 cm(2)/m(2) to < or = 0.85 cm(2)/m(2)), 1,584 (47.4%); and severe (< 0.65 cm(2)/m(2)), 212 (6.3%). RESULTS: The predictors of overall mortality were age, age categorization, New York Heart Association functional class III/IV, concomitant coronary artery bypass graft surgery, prosthesis type, preoperative congestive heart failure, diabetes mellitus, renal failure, and chronic obstructive pulmonary disease. All categories of effective orifice area indexes were not predictive of overall mortality, late mortality, or early mortality. The 15-year overall survival was differentiated by effective orifice area index categories: 38.1% +/- 2.1%, 37.0% +/- 2.2%, and 22.1% +/- 6.5%, respectively, for the three categories. Survival adjusted for the covariates (effective orifice area index, age, basal mass index, and ejection fraction) determined no effect except severe effective orifice area index when adjusted for ejection fraction more than 50% (p = 0.049). CONCLUSIONS: Prosthesis-patient mismatch is not a predictor of overall standard unadjusted mortality to 15 years after aortic valve replacement, regardless of the category of effective orifice area index.

Seven-year results with the St Jude Medical Silzone mechanical prosthesis.

OBJECTIVE: The Artificial Valve Endocarditis Reduction Trial was stopped on January 21, 2000, due to a higher incidence of paraprosthetic leak in the St Jude Medical Silzone prosthesis compared with the conventional prosthesis. The Artificial Valve Endocarditis Reduction Trial investigators reported the 2-year results in 2002. This retrospective study assessed the influence on thromboembolism and paraprosthetic leak to 7 years. METHODS: A total of 253 patients had 254 operations: 80 aortic valve replacements, 139 mitral valve replacements, and 35 multiple replacements with placement of Silzone prostheses. The mean age was 58.6 years (range 21-84 years, median age 59.8 years), and there were 126 women (49.8%) and 74 concomitant procedures (coronary artery bypass 28.9%). RESULTS: Major paraprosthetic leak (repair, re-replacement, or mortality) occurred in 10 of the original procedures after 30 days (3 aortic valve replacements, 3 mitral valve replacements, 4 multiple replacements). Nine occurrences in 8 patients-5 early (2 years)-were managed. Seven were managed with definitive re-replacement. One was an early nonoperative fatality. There was 1 late fatality after the second late paraprosthetic leak reoperation. One of the 10 procedures occurring after 2 years had mild to moderate aortic valve replacement paraprosthetic leak managed as an incidental re-replacement at the time of correction of supra valvular patch stenosis. One additional occurrence, in addition to the 8 patients (<30 days), was considered a technical error and not related to the Silzone prosthesis and was replaced with a Silzone prosthesis. The linearized rate of paraprosthetic leak within the first 2 years of follow-up was 1.3%/patient-year and after 2 years was 0.4%/patient-year. The linearized occurrence rate for major thromboembolism was 0.42%/patient-year for aortic valve replacement and 1.71%/patient-year for mitral valve replacement. CONCLUSIONS: Paraprosthetic leak with the St Jude Medical Silzone prosthesis was managed both during the early (2years) intervals with re-replacement. Late managed events may be manifestations of earlier occurring paraprosthetic leak. Follow-up echocardiograms should meet standards of care, 6 to 12 months after surgery and at the slightest suspicion of dysfunction. There is no advanced continuing risk of the St Jude Medical Silzone prosthesis.

Effect of prosthesis-patient mismatch on long-term survival with mitral valve replacement: assessment to 15 years.

BACKGROUND: The effect of prosthesis-patient mismatch on long-term survival after mitral valve replacement (MVR) has received limited attention. This study was performed to determine the predictors of mortality after MVR and influence of prosthesis-patient mismatch on survival. METHODS: Contemporary mechanical prostheses and bioprostheses were implanted in 2,440 patients with MVR between 1982 and 2002. The mean age was 63.9 +/- 12.1 years and the mean follow-up was 6.1 +/- 4.6 years, a total of 14,797.7 years of follow-up. Prosthesis-patient mismatch was classified by effective orifice area index categories: normal, greater than 1.2 cm(2)/m(2) (345, 14.2%); mild-to-moderate, equal to or less than 1.2 to greater than 0.9 cm(2)/m(2) (1,696, 69.5%); and severe, equal to or less than 0.9 cm(2)/m(2) (399, 16.4%). RESULTS: The predictors of overall mortality were age, age categorization, New York Heart Association III-IV, concomitant coronary artery bypass, ventricular dysfunction, prosthesis type, body mass index, and pulmonary hypertension. All categories of effective orifice area indices (EOAIs) were not predictive of overall mortality, late mortality, or early mortality. The 15-year survival was not differentiated by EOAI categories; 32.0 +/- 4.4%, 32.9 +/- 2.1%, and 36.6 +/- 6.3%, respectively, for the three categories. Pulmonary hypertension influenced mortality by EOAI categories; normal versus mild-to-moderate (p = 0.0317) and normal versus severe (p = 0.0320). The EOAI was not an independent predictor of mortality in the consideration of patients with pulmonary hypertension but there is an interaction between pulmonary hypertension and mild-to-moderate (p = 0.023) and severe (p = 0.031) EOAI. CONCLUSION: Prosthesis-patient mismatch is not a predictor of overall mortality to 15 years after MVR regardless of the category of effective orifice area index. The preoperative variable, pulmonary hypertension, influences overall mortality in the presence of mild-to-moderate and severe prosthesis-patient mismatch in the survival analysis.

Patient outcome after aortic valve replacement with a mechanical or biological prosthesis: weighing lifetime anticoagulant-related event risk against reoperation risk.

OBJECTIVE: Although the results of aortic valve replacement with different valve prostheses are well documented in terms of survival, the risks of (valve-related) events are less well explored. METHODS: We used a dataset of 3934 patients who underwent aortic valve replacement with either a bioprosthesis (73%) or a mechanical prosthesis (27%) between 1982 and 2003 to simulate the outcome of patients after aortic valve replacement with either valve type. With the use of microsimulation, we compared total age and gender-specific life expectancy, event-free life expectancy, reoperation-free life expectancy, lifetime risks of reoperation, and valve-related events for both valve types. RESULTS: The total follow-up was 26,467 patient-years. The mean follow-up was 6.1 years in the biological arm and 8.5 years in the mechanical arm. The mean age at implantation was 70 and 58 years for biological and mechanical prostheses, respectively, and the percentage of concomitant coronary artery bypass grafting was 47% and 28%, respectively. For a 60-year-old man, simulated life expectancy in years for biological versus mechanical prostheses was 11.9 versus 12.2, event-free life expectancy was 9.8 versus 9.3, and reoperation-free life expectancy was 10.5 versus 11.9. Lifetime risk of reoperation was 25% versus 3%. Lifetime risk of bleeding was 12% versus 41%. CONCLUSION: Even for patients aged 60 years, event-free life expectancy is better with a bioprosthesis. Although the chance of reoperation is higher, the lifetime risk of bleeding is lower compared with a mechanical prosthesis. Comparing lifetime event risks between different types of valve prostheses provides more insight into patient outcome after aortic valve replacement and aids patient selection and counseling.