Reoperation of left heart valve bioprostheses according to age at implantation.

BACKGROUND: Evidence supporting the use of bioprostheses for heart valve replacement in young adults is accumulating. However, reoperation data, which may help guide clinical decision making in young patients, remains poorly defined in the literature. METHODS AND RESULTS: We examined the need for reoperation in 3975 patients who underwent first-time bioprosthetic aortic valve replacement (AVR) (n=3152) or mitral valve replacement (MVR) (n=823). There were 895 patients below the age of 60 years at bioprosthesis implant (AVR, n=636; MVR, n=259). The median interval to reoperation of contemporary, stented aortic bioprostheses was 7.74 years (95% CI 7.28 to 9.97 years) in patients less than 40 years, and 12.93 years (95% CI 11.10 to 15.76 years) in patients between 40 and 60 years of age. Multivariable risk factors associated with reoperation following bioprosthetic AVR include age (hazard ratio [HR] 0.94 per year, 95% CI 0.91 to 0.96, P<0.001) and concomitant coronary artery bypass grafting (HR 0.34, 95% CI 0.11 to 0.99, P=0.04). The median interval to reoperation of contemporary mitral bioprostheses was 8.11 years (95% CI 5.79 to 16.50 years) in patients less than 40 years, and 10.14 years (95% CI 8.64 to 11.14 years) in patients between 40 and 60 years of age. As for AVR, age (HR 0.96 per year, 95% CI 0.95 to 0.98, P<0.001) and concomitant coronary artery bypass grafting (HR 0.55, 95% CI 0.32 to 0.93, P=0.03) were associated with decreased reoperation risk following bioprosthetic MVR. CONCLUSIONS: These data constitute clinically relevant age-specific prognostic information regarding reoperation in young patients, who may wish to select a bioprosthesis at initial left heart valve replacement.

Very long-term survival implications of heart valve replacement with tissue versus mechanical prostheses in adults <60 years of age.

BACKGROUND: Several centers favor replacing a diseased native heart valve with a tissue rather than a mechanical prosthesis, even in younger adult patients. However, long-term data supporting this approach are lacking. We examined the survival implications of selecting a tissue versus a mechanical prosthesis at initial left-heart valve replacement in a cohort of adults <60 years of age who were followed for over 20 years. METHODS AND RESULTS: Comorbid and procedural data were available from 6554 patients who underwent valve replacement at our institution over the last 35 years. Of these, 1512 patients contributed follow-up data beyond 20 years, of whom 567 were adults <60 years of age at first left-heart valve operation (mean survivor follow-up, 24.0+/-3.1 years). Late outcomes were examined with Cox regression. Valve reoperation, often for prostheses that are no longer commercially available, occurred in 89% and 84% of patients by 20 years after tissue aortic and mitral valve replacement, respectively, and was associated with a mortality of 4.3%. There was no survival difference between patients implanted with a tissue versus a mechanical prosthesis at initial aortic valve replacement (hazard ratio 0.95; 95% CI: 0.7, 1.3; P=0.7). For mitral valve replacement patients, long-term survival was poorer than after aortic valve replacement (hazard ratio 1.4; 95% CI: 1.1, 1.8; P=0.003), but again no detrimental effect was associated with use of a tissue versus a mechanical prosthesis (hazard ratio 0.9; 95% CI 0.5, 1.4; P=0.5). CONCLUSIONS: In our experience, selecting a tissue prosthesis at initial operation in younger adults does not negatively impact survival into the third decade of follow-up, despite the risk of reoperation.

Skeletonized internal thoracic artery harvest reduces pain and dysesthesia and improves sternal perfusion after coronary artery bypass surgery: a randomized, double-blind, within-patient comparison.

BACKGROUND: Observational studies suggest that skeletonization of the internal thoracic artery (ITA) can improve conduit flow and length and reduce deep sternal infections and postoperative pain. We performed a randomized, double-blind, within-patient comparison of skeletonized and nonskeletonized ITAs in patients undergoing coronary surgery. METHODS AND RESULTS: Patients (n = 48) undergoing bilateral ITA harvest were randomized to receive 1 skeletonized and 1 nonskeletonized ITA. Intraoperatively, ITA flow was assessed directly and with a Doppler flow probe before and after topical application of papaverine. ITA harvest time and conduit length were recorded. A blinded assessment of pain (visual analog scale) and dysesthesia (physical examination) was performed at discharge, at 2 weeks, and at a 3-month follow-up. Sternal perfusion was assessed with nuclear imaging (n = 7). Skeletonization required longer ITA harvest times (27 +/- 1 versus 24 +/- 1 minutes; P = 0.04). There was a trend toward increased ITA length in the skeletonized group (18.2 +/- 0.3 versus 17.7 +/- 0.3 cm; P = 0.09). In situ ITA flow was lower in skeletonized arteries (7.4 +/- 0.9 versus 10.1 +/- 1.0 mL/min; P = 0.01) and increased significantly after ITA division and papaverine application. Postanastomotic flows were similar between groups. Skeletonization was associated with decreased pain at the 3-month follow-up and a reduction in major sensory deficits at the 4-week and 3-month (17% versus 50%; P = 0.002) follow-ups. Baseline adjusted sternal perfusion was significantly greater by 17 +/- 6% (P = 0.03) on the skeletonized side. CONCLUSIONS: Skeletonization results in reduced postoperative pain and dysesthesia and increased sternal perfusion at follow-up but does not produce increased conduit flow. ITA skeletonization may be a strategy for reducing morbidity after CABG.

Management of acute severe perioperative failure of cardiac allografts: a single-centre experience with a review of the literature.

BACKGROUND: Early graft failure is associated with high mortality and is the main cause of death within the first 30 days after transplantation. The purpose of the present study was to examine the investigators' experience of severe perioperative acute graft failure and to review the literature. METHODS: Nine of 385 cardiac transplants (2.3%) performed from 1984 through 2005 developed severe perioperative acute graft failure either in the operating room or within 24 h after cardiac transplantation. Four patients had primary graft failure, two had right heart failure secondary to pulmonary hypertension, one had hyperacute rejection, one had accelerated acute rejection and one possibly sustained a particulate coronary embolus intraoperatively. RESULTS: All except the two patients who had right heart failure secondary to pulmonary hypertension received mechanical circulatory support. Three patients were supported with total artificial hearts, two patients received a left ventricular assist device, one patient was supported with extracorporeal life support followed by a right ventricular assist device when the left ventricle recovered, and one patient was supported for several hours with cardiopulmonary bypass. Three patients were retransplanted after mechanical circulatory support, but only one survived. Only one of the nine patients (11%) survived; this patient was supported with a total artificial heart followed by retransplantation. CONCLUSION: The outcome of severe perioperative acute graft failure is very poor. Mechanical circulatory support and retransplantation are not as successful as in other situations. Due to the shortage of donors and poor outcomes, retransplantation for hyperacute rejection is not advisable.

Combined atrial fibrillation ablation with mitral valve surgery.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the efficacy and outcome of radiofrequency (RF) atrial fibrillation (AF) ablation in patients undergoing mitral valve (MV) surgery. METHODS: Between March 2002 and December 2004, 61 patients (mean age 65.4 +/- 10 years) underwent isolated endo-left atrial AF ablation using a unipolar RF device (Cardioblate; Medtronic, USA) in conjunction with 34 MV repairs and 27 MV replacements. AF was paroxysmal in 13 patients (21%), and permanent in 48 (79%), with a mean duration of 3.6 +/- 3.5 years. The etiology was degenerative in 35 patients (57%), rheumatic in 17 (28%), and ischemic in nine (17%). All patients received amiodarone postoperatively. RESULTS: No patients died during the study, and there were no thromboembolic complications. All patients had intraoperative conversion. Forty-one patients (67%) presented with postoperative relapse; definitive conversion was achieved in 34 (83%) cases within three months. The overall success rate was 75.4% at 14 +/- 8.8 months; success was greater in the MV repair group (85%) than in the MV replacement group (66.7%), though not significantly so (p = 0.09). Factors associated with definitive conversion included smaller left atrial size (p = 0.007), decreased left ventricular end-diastolic diameter (p = 0.04), and NYHA class I (p = 0.05). Age, AF duration and etiology were not associated with conversion, but associated coronary artery bypass grafting showed a strong trend towards significance (p = 0.07). In these patients, AF duration did not predict conversion to sinus rhythm. CONCLUSION: Combined AF ablation with MV surgery is safe and effective. Although AF ablation seems more beneficial with MV repair, the success rate may vary significantly according to patient characteristics.

Early postoperative anticoagulation after mechanical valve replacement: a Canadian survey.

BACKGROUND AND AIM OF THE STUDY: The optimal approach to anticoagulation during the early postoperative period after mechanical valve replacement, by which early thromboembolism is prevented without bleeding complications, is not yet known. The study aim was to examine the practice patterns of Canadian cardiac surgeons with regard to early postoperative anticoagulation after mechanical valve implantation. METHODS: A questionnaire was sent to 100 Canadian cardiac surgeons in July 2004, and 57 responses were received. Data were collected regarding the approaches to early postoperative anticoagulation following uncomplicated isolated mechanical aortic valve replacement (AVR) and mitral valve replacement (MVR). RESULTS: Heparin was administered routinely after AVR and MVR by 63% and 68% of surgeons, respectively. This was most commonly initiated on postoperative day (POD) 1, and given either subcutaneously (AVR, 28%; MVR, 25%) or intravenously (AVR, 33%; MVR, 42%). Alternatively, low-molecular-weight heparin was used by 21% and 23% of surgeons after AVR and MVR, respectively. Oral warfarin was usually started on POD 1 (72% and 68%, respectively), with 40% prescribing an initial dose between 2.5 and 5.0 mg, and 51% administering between 5.1 and 7.5 mg. When heparin was not used, oral anticoagulation was more often administered earlier (AVR, p = 0.003; MVR, p = 0.006), but not at higher doses (AVR, p = 0.07; MVR, p = 0.2). Following surgery, aspirin was prescribed by 61% and 65% of surgeons after AVR and MVR, respectively. CONCLUSION: The study results highlighted a significant variability in the management of early postoperative anticoagulation after mechanical valve implantation. The clinical impact of these findings is unknown, and can only be assessed through a prospective trial.

Mechanical versus bioprosthetic valve replacement in middle-aged patients.

OBJECTIVE: The current trend towards decreasing the age for selection of a tissue over a mechanical prosthesis has led to a dilemma for patients aged 50-65 years. This cohort study examines the long-term outcomes of mechanical versus bioprosthetic valves in middle-aged patients. METHODS: Patients (N = 659) aged between 50 and 65 years who had first-time aortic valve replacement (AVR) and/or mitral valve replacement (MVR) with contemporary prostheses were followed prospectively after surgery. The total follow-up was 3,402 patient-years (mean 5.1 +/- 4.1 years; maximum 18.3 years). Outcomes were examined with multivariate actuarial methods. A composite outcome of major adverse prosthesis-related events (MAPE) was defined as the occurrence of reoperation, endocarditis, major bleeding, or thromboembolism. RESULTS: Ten-year survival was 73.2 +/- 4.2% after mechanical AVR, 75.1 +/- 12.6% after bioprosthetic AVR, 74.1 +/- 4.6% after mechanical MVR, and 77.9 +/- 7.4% after bioprosthetic MVR (P=NS). Ten-year reoperation rates were 35.4% and 21.3% with aortic and mitral bioprostheses, respectively. Major bleeding occurred more often following mechanical MVR (hazard ratio [HR]: 3.3; 95% confidence interval [CI] 1.2, 9.0; P = 0.022), and the incidence of any thromboembolic event was more common after mechanical MVR (HR: 4.7; CI 1.4, 13.3; P = 0.01). Overall freedom from MAPE at 10 years was 70.2 +/- 4.1% for mechanical AVR patients, 41.0+/-30.3% for bioprosthetic AVR patients, 53.3 +/- 8.8% for mechanical MVR patients, and 61.2 +/- 9.2% for bioprosthetic MVR patients. Although a trend existed towards more MAPE amongst middle-age patients with tissue valves, multivariate analysis did not identify the presence of a bioprosthesis as an independent risk factor for MAPE (HR: 1.3; CI 0.9, 2.0; P = 0.22). CONCLUSIONS: In middle-aged patients, MAPE may occur more often in patients with bioprosthetic valves, but definitive conclusions necessitate the accumulation of additional follow-up. At present, these data do not support lowering the usual cutoff for implantation of a tissue valve below the age of 65.

Surgical treatment of atrial fibrillation with diathermy: an in vitro study.

OBJECTIVE: The utilization of diathermy (electrocautery) as an energy source in the treatment of chronic atrial fibrillation has generated positive early clinical results. Although this technology is available and affordable, it has not been well studied for this indication. The objectives of this study were: (1) to characterize atrial lesions created by diathermy, (2) to determine relationships between power setting, tissue contact time, and lesion depth and (3) to histologically compare diathermy and unipolar radiofrequency lesions. METHODS: Fresh bovine atrial tissue samples were used to create endocardial lesions using a unipolar diathermy system with a blade tip. A total of 120 lesions were created at varying power settings and tissue contact times. Subendocardial temperatures were recorded. All lesions were examined grossly, then fixed, sectioned and evaluated histologically by a blinded pathologist. Comparisons were made with saline irrigated unipolar radiofrequency lesions. RESULTS: Gross examination revealed extensive tissue destruction of the endocardial surface at the point of contact. Histological examination showed minimal penetrance of the lesions beyond the destroyed tissue margin of the endocardium. This was corroborated by the finding of minimal thermal penetration beyond the endocardium and superficial myocardium. There was a linear relationship between the power setting (15-55 watts), depth of penetrance (2-15 mm) at varying contact times (1-5s/cm). CONCLUSIONS: In this in vitro model, lesions created by diathermy were not transmural, even with high power settings and prolonged contact times. At these settings, significant tissue destruction was observed that may predispose to atrial perforation without achieving penetration. Diathermy did not constitute an effective energy source in the creation of transmural lesions for atrial fibrillation ablation.

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

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

Clinical evaluation of functional mitral stenosis after mitral valve repair for degenerative disease: potential affect on surgical strategy.

BACKGROUND: Mitral annuloplasty with either a partial band or complete ring is an integral part of mitral valve repair for degenerative disease. The affect of annuloplasty type on outcomes has not been well described. The objective of our study was to compare echocardiographic and functional characteristics of patients who underwent mitral repair with either a complete ring or a partial band. METHODS: We evaluated 107 patients who underwent mitral repair of myxomatous degeneration at our institution by stress echocardiography, 6-minute walk testing, and short form-36 questionnaire. These assessments were performed 4.3 ± 2.2 years following mitral repair by a single surgeon. A band was used in 65 patients (61%) and a ring in 42 patients (39%). Parametric and nonparametric tests were used in the analyses. RESULTS: The labeled band and ring size used for repair were 30.7 ± 2.8 mm and 30.4 ± 2.1 mm, respectively (P = .6). The resting mean mitral gradient and valve area were 3.7 ± 1.9 mm Hg and 2.3 ± 0.6 cm(2) for patients who received a band and 5.8 ± 2.6 mm Hg and 1.8 ± 0.5 cm(2) for patients who received a ring (both P < .001). Distance traversed on 6-minute walk testing was 471 ± 77 m in the band group and 443 ± 107 m in the ring group (P = .1). At peak exercise, the mean mitral gradient (15.3 ± 8.2 mm Hg vs 10.6 ± 4.8 mm Hg; P < .001) and right ventricular systolic pressure (52.6 ± 14.2 mm Hg vs 45.8 ± 9.5 mm Hg; P = .004) were higher for patients who received a ring versus a band. Ring patients reported lower levels of energy (P = .02) and general health (P = .007) on short form-36 assessment. CONCLUSIONS: Annuloplasty using a complete ring may be associated with a higher mitral valve gradient at rest and at peak exercise in certain patients. These patients may also have worse quality of life. In view of these findings, we recommend careful consideration of annuloplasty type and size at the time of mitral repair of organic disease.

Long-term evaluation of biological versus mechanical prosthesis use at reoperative aortic valve replacement.

OBJECTIVES: Recent evidence indicated that the use of a bioprosthesis in young patients at first-time aortic valve replacement (AVR) is associated with an increased reoperation risk, but not with an increase in long-term mortality, when compared with the use of a mechanical valve. However, at reoperative AVR, follow-up data by prosthesis type have been lacking from the literature. Therefore, we examined long-term survival and valve-related complications according to the type of prosthesis used at reoperative AVR. METHODS: We studied 437 patients who underwent reoperative AVR, at a mean age of 58.6 ± 14.2 years, for failure of a previously implanted aortic valve prosthesis. Thirty-day mortality at reoperative AVR was 6% (n = 27). A bioprosthesis was used in 135 (31%) patients. Patients were subsequently followed up for a mean of 7.6 ± 6.8 years after reoperative AVR. RESULTS: The use of a bioprosthesis at reoperative AVR was not associated with impaired survival on adjusted analysis (hazard ratio [HR], 0.8 ± 0.4; P = .6). Freedom from thromboembolism, and endocarditis were similar between valve types (both P > .05); however, late postoperative major hemorrhage occurred only in patients who received a mechanical prosthesis at reoperative AVR. Risk factors for third-time AVR included the use of a bioprosthesis (HR, 14.0) and younger age (HR, 1.05 per decreasing year) at reoperative AVR (both P < .001). Thirty-day mortality of third-time AVR was 4% (n = 1/27). CONCLUSIONS: At reoperative AVR, the use of a bioprosthesis is associated with equivalent long-term survival compared with a mechanical prosthesis. Patients who receive a bioprosthesis at reoperative AVR are less likely to experience major hemorrhage but more likely to require third-time AVR, albeit with an acceptable third-time perioperative mortality risk. Therefore, the patient's informed preferences regarding prosthesis choice should prevail, even in a reoperative context.

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.

Postoperative lipid-lowering therapy and bioprosthesis structural valve deterioration: justification for a randomised trial?

OBJECTIVE: Bioprosthesis structural valve deterioration (SVD) is an incompletely understood process involving the accumulation of calcium and lipids. Whether this process could be delayed with lipid-lowering therapy (LLT) is currently unknown. The purpose of this observational study was to evaluate if an association exists between early LLT and a slowing of bioprosthesis SVD, with a view to designing a prospective trial. METHODS: We followed 1193 patients who underwent aortic valve replacement with contemporary bioprostheses between 1990 and 2006 (mean follow-up 4.5+/-3.1 years, maximum 17.3 years). Of these patients, 150 received LLT (including statins) early after surgery. Prosthetic valve haemodynamics on echocardiography and freedom from re-operation for SVD were compared between patients who did and did not receive postoperative LLT. RESULTS: After bioprosthetic implantation, the progression of peak and mean trans-prosthetic gradients during echocardiographic follow-up (mean 3.3 years) was equivalent between patients treated with and without LLT (peak increase: 0.9+/-7.7 vs 1.1+/-10.9 mmHg, LLT vs no LLT, P=0.87; mean increase: 0.8+/-4.1 vs 0.2+/-5.9 mmHg, LLT vs no LLT, P=0.38). The annualised linear rate of gradient progression following valve replacement was also similar between groups (peak increase per year: 2.0+/-12.1 vs 1.0+/-12.9 mmHg per year, LLT vs no LLT, P=0.52; mean increase per year: 0.5+/-2.2 vs 0.6+/-6.0 mmHg per year, LLT vs no LLT, P=0.94). The incidence of mild or greater aortic insufficiency on the most recent echocardiogram was comparable (16.3% vs 13.8%, LLT vs no LLT, P=0.44), and there was no difference in the 10-year freedom from re-operation for SVD between the two groups [98.9% (95% confidence interval (CI): 91.9%, 99.8%) vs 95.4% (95% CI 90.5%, 97.9%), LLT vs no LLT, P=0.72]. CONCLUSIONS: In this observational study, there was no association demonstrated between early postoperative LLT and a slowing of bioprosthesis SVD. With the excellent durability of bioprostheses in the current era, a prospective randomised trial of statin therapy to prevent bioprosthetic SVD does not appear to be justified, let alone feasible.

Clinical and echocardiographic impact of functional tricuspid regurgitation repair at the time of mitral valve replacement.

BACKGROUND: The indications for tricuspid valve repair in the setting of mitral valve disease and concomitant tricuspid regurgitation (TR) remain unclear. We examined patients undergoing mitral valve replacement (MVR) to determine the effect of TR and tricuspid valve repair on survival, functional status, and postoperative TR. METHODS: Between 1990 and 2005, 624 patients underwent MVR. Data included detailed serial echocardiographic tricuspid valve measurements, functional status, and survival data. Preoperative TR exceeded 2+ in 231: 125 received tricuspid repair and MVR, whereas 106 received MVR alone. Clinical and echocardiographic follow-up were complete (average, 6.8 +/- 4.8 years). Parametric and semi-parametric tests were used to analyze outcomes. RESULTS: TR exceeding 2+ at operation was associated with a 53% increase in late death (p = 0.003). Tricuspid repair prevented echocardiographic progression of TR and improved congestive heart failure symptoms (both p < 0.01). Overall survival did not improve (p = 0.3). A trend to worsening TR in patients was noted with a larger tricuspid annulus diameter and without significant (

Enlargement of the small aortic root during aortic valve replacement: is there a benefit?

BACKGROUND: Aortic root enlargement (ARE) at the time of aortic valve replacement (AVR) is an often proposed but still unproven technique to prevent prosthesis-patient mismatch. To evaluate the risks and benefits of ARE, we examined the outcomes of patients with small aortic roots who underwent AVR with or without the use of ARE. METHODS: Patients (n = 712) with small aortic roots who underwent AVR were prospectively followed (follow-up, 3,730 patient-years; mean, 5.2 +/- 4.1 years). All patients had a small aortic annulus that would have led to the insertion of an aortic prosthesis of 21 or less in size. Multivariate techniques were used to compare outcomes between patients who underwent AVR alone (n = 540) versus AVR plus ARE (n = 172). RESULTS: Aortic cross-clamp times were 9.9 minutes longer in the AVR+ARE group (p = 0.0002). There were no differences in reopening or stroke rates or perioperative mortality (all p = not significant). All patients in the AVR-alone group received size 19 to 21 prostheses, whereas 51% of the AVR+ARE patients received size 23 prostheses. Postoperative gradients were reduced (p < 0.01) and indexed effective orifice areas were larger (p < 0.0001) in the AVR+ARE group. While the incidence of postoperative prosthesis-patient mismatch (indexed effective orifice area < or = 0.85 cm2/m2) was lower in the AVR+ARE group (p < 0.0001), the presence of mismatch did not significantly impact long-term outcomes after surgery. The ARE was associated with a trend toward better freedom from late congestive heart failure (p = 0.19), but not an improvement in long-term survival (p = 0.81). CONCLUSIONS: For patients with small aortic roots, ARE at the time of AVR is a safe procedure that reduces postoperative gradients and the incidence of prosthesis-patient mismatch. However, ARE does not appreciably improve long-term clinical outcomes.

The internal thoracic artery skeletonization study: a paired, within-patient comparison [NCT00265499].

BACKGROUND: Traditional harvesting of the internal thoracic artery (ITA) for use as a conduit in coronary bypass surgery involves the dissection of a rim of tissue surrounding the artery on either side. Recent studies, primarily observational, have suggested that skeletonization of the ITA can improve conduit flow, increase length, and reduce the risk of deep sternal infection in high risk patients. Furthermore, skeletonization of the ITA can potentially preserve intercostal nerves and reduce post-operative pain and dysesthesias associated with ITA harvesting. In order to assess the effects of ITA skeletonization, we report a prospective, randomized, within-patient study design that shares many features of a cross-over study. METHODS: Patients undergoing bilateral internal thoracic artery harvest will be randomized to having one side skeletonized and the other harvested in a non-skeletonized manner. Outcome measures include ITA flow and length measured intra-operatively, post-operative pain and dysesthesia, evaluated at discharge, four weeks, and three months post-operatively, and sternal perfusion assessed using single photon emission computed tomography. Harvest times as well as safety endpoints of ITA injury will be recorded. DISCUSSION: This study design, using within-patient comparisons and paired analyses, minimizes the variability of the outcome measures, which is seldom possible in the evaluation of surgical techniques, with minimal chance of carryover effects that can hamper the interpretation of traditional cross-over studies. This study will provide a valid evaluation of clinically relevant effects of internal thoracic artery skeletonization in improving outcomes following coronary artery bypass surgery.

Early postoperative anticoagulation after mechanical valve replacement: a systematic review.

The optimal approach to early postoperative anticoagulation after mechanical valve implantation remains controversial. This review article examines the pathogenesis of thrombus formation and the different strategies for early postoperative anticoagulation. The most commonly reported anticoagulation regimens had the after estimates of early postoperative thromboembolism and hemorrhage: oral anticoagulation alone (0.9%, 3.3%); oral anticoagulation with intravenous unfractionated heparin (1.1%, 7.2%); and oral anticoagulation with low molecular weight heparin (0.6%, 4.8%). Although intravenous heparin may be associated with a higher incidence of hemorrhage, a randomized trial is needed to provide the best evidence regarding early postoperative anticoagulation after mechanical valve implantation. Nearly four decades have passed since the first mechanical prosthetic valves were implanted. Frequent thromboembolic complications with the first mechanical valves led to recommendations of universal anticoagulation for these patients. Since then, several design changes and modifications have been made to improve the longevity, hemodynamics, and thrombogenicity of newer generation mechanical valves. With improved blood flow, less stasis, and less thrombogenic materials, lower rates of thromboembolism have been reported. Despite these advances however, thromboembolism and anticoagulant-related bleeding continue to account for 75% of all complications after mechanical valve replacement. Occurring most commonly within six months after implantation, these complications can adversely affect mortality and quality of life. Furthermore, the threat of their occurrence creates a psychological burden for each patient with a mechanical valve. The need for life-long anticoagulation in patients with mechanical valves is not in dispute, and the perioperative management of anticoagulation during non-cardiac surgery has been reviewed extensively. However, the approach to early postoperative anticoagulation after mechanical valve implantation is still a matter of debate. The optimal intensity and timing of anticoagulation to prevent early thromboembolism after valve replacement surgery without postoperative bleeding complications is unknown. Hence, many anticoagulation protocols have been proposed, but a lack of consensus remains. The objectives of this study were (1) to reexamine the pathogenesis of thrombus formation and the need for anticoagulation; (2) to critically review the literature on early postoperative anticoagulation strategies; and (3) provide an estimate of the incidence of bleeding and thromboembolism for each approach to early postoperative anticoagulation.

Importance of moderate ischemic mitral regurgitation.

BACKGROUND: The importance of moderate ischemic mitral regurgitation in patients presenting for coronary artery bypass grafting (CABG) is controversial. Therefore, we tracked the course of unrepaired moderate ischemic mitral regurgitation after CABG surgery alone, identified factors associated with worsening postoperative ischemic mitral regurgitation, and assessed the impact of unrepaired moderate ischemic mitral regurgitation on survival. METHODS: From 1980 to 2000, 467 patients with moderate ischemic mitral regurgitation underwent CABG alone. The course of unrepaired mitral regurgitation was estimated by a longitudinal analysis of 267 follow-up echocardiograms from 156 patients. The survival impact of moderate ischemic mitral regurgitation was determined among propensity-matched patients with and without ischemic mitral regurgitation. RESULTS: Mitral regurgitation was dynamic early postoperatively. Immediately postoperatively, it was absent or mild in 73% and severe in 6%; by 6 weeks, these figures were 40% and 22%, respectively. The course of postoperative mitral regurgitation was not associated with the preoperative extent of coronary artery disease or left ventricular dysfunction. Five-year survival of matched bypass patients without ischemic mitral regurgitation was 85% compared with 73% for patients with moderate ischemic mitral regurgitation (p = 0.003). CONCLUSIONS: Moderate ischemic mitral regurgitation does not reliably resolve with CABG surgery alone and is associated with reduced survival. Therefore, a mitral valve procedure may be warranted for such patients presenting for CABG. A randomized trial comparing strategies of revascularization with mitral valve repair and revascularization alone is required to determine optimal treatment.