Redo valvular surgery in elderly patients.

BACKGROUND: Elderly patients older than the age of 75 constitute 13% of the population that undergoes cardiac surgery at our institution and represent the fastest growing population in Ontario. We have witnessed an increasing proportion of elderly patients being referred for repeat surgical intervention for valvular heart disease. We determined the perioperative and long-term outcomes in elderly patients undergoing redo cardiac valve surgery. METHODS: A retrospective review of our institutional database identified 112 patients aged 75 years or older (mean age, 78 +/- 3 years; range, 75 to 89 years) who underwent redo valve surgery between 1990 and 2004. All patients presented with a previous surgical intervention on the valve of interest. The mean follow-up was 5 +/- 4 years and was 100% complete. RESULTS: Eighty-eight patients (79%) had isolated valve surgery at their primary operation whereas 24 patients (21%) had concomitant coronary artery bypass grafting at the time of their initial valve surgery. At reoperation, 74 patients (66%) underwent single valve surgery (40 aortic valve, 34 mitral valve), 33 patients (29.5%) required double valve surgery, and 5 patients (4.5%) had triple valve surgery. Thirty-three patients (29.5%) required concomitant coronary artery bypass grafting, among whom 14 patients had a previous coronary artery bypass graft surgery. There were 12 operative (10.7%) and 47 late deaths (42%). Cardiovascular events were the cause of death in 32 patients (54% of all deaths). Overall survival at 5 years was 67% +/- 5%. The freedom from valve-related mortality and morbidity was 86% +/- 4% at 5 years. Mean intensive care eunit stay was 3.7 +/- 4.5 days, and postoperative hospital stay was 15 +/- 12 days. CONCLUSIONS: Redo valvular surgery in an elderly cohort can be performed with acceptable morbidity and mortality. Although 5-year survival is lower than that observed with a younger patient population, it is still likely higher than expected survival without surgical intervention. Despite increased resource utilization, elderly patients should be offered redo surgical intervention for valvular heart disease.

Effect of prior valve type on mortality in reoperative valve surgery.

BACKGROUND: The purpose of this study is to examine the effect of previously implanted valve type on hospital mortality in reoperative valve surgery. METHODS: From 1990 to 2005, 743 patients underwent redo valve surgery at our institution. Patients were divided into those who received a mechanical valve during their prior operation (n = 236) and those who received a biological (porcine or pericardial) valve (n = 507). Perioperative data were analyzed retrospectively. RESULTS: Patients with failing mechanical valves were younger, more likely to be female, and had a higher prevalence of preoperative stroke and atrial arrhythmias, whereas patients with failing biological valves had more hypertension, diabetes mellitus, hyperlipidemia, and chronic obstructive pulmonary disease (all p < 0.05). Mechanical valve explant patients had fewer prior coronary bypass and aortic valve operations, but more mitral surgeries (all p < 0.05). Mechanical patients also had a higher prevalence of endocarditis (p = 0.001) and urgent or emergent surgery (p < 0.001). Hospital mortality was higher among patients undergoing mechanical valve explant by univariate analysis (13% versus 8%, p = 0.04), but not by multivariate analysis (odds ratio 1.6, 95% confidence interval 0.9 to 2.7, p = 0.1). Logistic regression revealed chronic obstructive pulmonary disease, peripheral vascular disease, endocarditis, and urgency of reoperation as independent predictors of hospital mortality. CONCLUSIONS: Explanting mechanical valves are associated with higher perioperative mortality than are tissue valves, likely because of different modes of failure and presentation. A lower risk of mortality for tissue valve reoperation may be an additional factor to consider when patients and surgeons choose a valve prosthesis type.

Pathologic analysis of 19 heart valves with silver-coated sewing rings.

OBJECTIVE: The St. Jude Medical Silzone (Silzone) mechanical heart valve was voluntarily recalled (January 2000) due to an unusually high incidence of paravalvular leaks. We present the first series of human morphological data on the failure of these valves. METHODS: Nineteen Silzone valves were evaluated from the 176 Silzone valves implanted in 147 patients at our institution between 1997 and 1999. Explanted prostheses were fixed in 10% formalin, photographed, and X-rayed. Histological sections were collected from the sewing cuff, accompanying tissues, and thrombus. For comparison, six age-matched SJM-standard valves were similarly analyzed. RESULTS: Nineteen Silzone valves from 16 patients (10 male, six female, 52.0 +/- 15.2 years) were examined. Significantly more mitral (15/95) prostheses were removed than aortic (4/81) despite the nearly equal number implanted (p = 0.027). Fifteen of the Silzone valves (13/16 patients) were explanted in the early postoperative period (within six months of implantation), although collection continued for eight years after our institution stopped implanting them. The common indications for surgical explantation were paravalvular leak (8/12) and clinically suspected infective endocarditis (IE) (four patients, five valves). IE was not confirmed by histology or culture in any valve. The sewing cuffs of many Silzone valves showed large regions of pannus, granulation tissue, and purulent exudate. Polymorphonuclear leukocytes were more common in the sewing cuff of Silzone valves; however, the cellular infiltrate was superficial when compared to SJM-standard valves. CONCLUSION: This is the largest morphologically analyzed series of Silzone explants. It demonstrates a consistent pattern of atypical tissue incorporation into the silver-coated sewing ring particularly in the mitral position. Clinical and morphologic features of IE (sterile) are seen in the early postimplant period. Prosthesis-related problems were almost wholly seen at the mitral site, in our group. Our current data indicate that although early failure due to dehiscence and paravalvular leak is a problem, Silzone valves that "survive" past six months will likely function as well as the SJM-standard prosthesis.

Short- and long-term results of triple valve surgery in the modern era.

BACKGROUND: Triple valve surgery is usually complex and carries a reported operative mortality of 25% and 10-year survival of 40%. We examined surgical results in the modern era. METHODS: A total of 174 consecutive patients, mean age 58 +/-12 years underwent triple valve surgery from 1990 to 2004. The most common aortic and mitral valve disease was rheumatic disease (61%), followed by prosthetic valve dysfunction (22%). Tricuspid valve disease was functional regurgitation in 72% of patients. Ninety-four percent of patients were in New York Heart Association class III and IV, and 60% had had previous cardiac operations. The aortic valve procedures consisted of 160 replacements and 14 repairs, the mitral valve procedures, 153 replacements and 21 repairs, and the tricuspid valve procedures, 12 replacements and 162 repairs. Univariate and multivariable analyses were performed to identify predictors of early and late survival. RESULTS: Operative mortality was 13% (n = 22). Univariate factors associated with mortality included urgent surgery, shock, tricuspid valve replacement, preoperative renal failure, and peripheral vascular disease. Survival at 5 and 10 years was 75% and 61%, respectively. Seventy-three percent of patients were in New York Heart Association class I and II at their most recent follow-up. Ten-year freedom from thromboembolism was 88%, from anticoagulation-related hemorrhage, 83%, from endocarditis, 96%, and from cardiac reoperation, 92%. CONCLUSIONS: Patients with advanced rheumatic valve disease and prosthetic valve dysfunction are at risk for requiring triple valve surgery. Compared with historic reports, the results of triple valve surgery, primary and reoperative, have improved. Although early mortality is high, long-term and event-free survival are comparable with that of patients undergoing single valve replacement.

Morphological findings in explanted Toronto stentless porcine valves.

BACKGROUND: Stentless porcine valves have many documented advantages over stented valves. Since its introduction in 1991, the Toronto stentless porcine valve (T-SPV) has shown excellent hemodynamic performance. METHODS: A total of 332 T-SPVs have been implanted at our institution up to December 2003, 25 of which have been explanted at surgery. Herein, we report a study of 30 explanted T-SPVs seen at our institution over a 5-year period. RESULTS: The mean patient age at explant was 61.2+/-11.8 years with a mean implant duration of 100.7+/-27.8 months (after excluding one valve removed early postoperatively for infective endocarditis). Twenty-seven of 30 valves (90%) showed structural deterioration characterized by tissue degeneration, cusp tears, calcification, and lipid insudation. Eight valves (26.7%) showed evidence of calcification on gross inspection and a total of 23 valves (76.7%) showed at least one microscopic focus of calcification, located primarily in the basal and commissural regions of the cusp. Twenty valves (66.6%) showed cusp tears. Pannus was visible grossly on the surface of 27 of 30 valves (90%), while histologically, at least some degree of pannus was observed on both the inflow and outflow surfaces of all but two valves. Twelve T-SPV (40.0%) showed calcification in the porcine aortic tissue, four of which involved calcification of the porcine muscle shelf in the right coronary cusp. Two T-SPV showed no significant structural deterioration. Their clinical reason for explantation was incompetence or infective endocarditis. CONCLUSION: With a freedom from reoperation of about 87.0% at up to 10 years, the T-SPV shows excellent durability. The majority of explanted valves show structural valve deterioration similar to that seen in other porcine heart valves.

Stentless aortic valves are hemodynamically superior to stented valves during mid-term follow-up: a large retrospective study.

BACKGROUND: Several studies have compared left venticular mass (LVM) regression and hemodynamic data for stentless versus stented aortic bioprostheses with conflicting results. The major limitations of these studies are their small sample size and short-term follow-up. We therefore compared midterm LVM regression, hemodynamic data, and survival in a large population of tissue aortic valve replacement (AVR) patients. METHODS: All patients undergoing tissue AVR at our institution between 1998 and 2001 were included (n = 737). Patients were divided into two groups according to type of bioprosthetic implanted: stentless patients (total n = 310) (Toronto SPV [St Jude Medical, St Paul, MN], n = 146 and Freestyle [Medtronic, Minneapolis, MN], n = 164) and stented patients (total n = 427) (Perimount [Edwards Life Sciences Inc, Irvine, CA], n = 291 and Mosaic [Medtronic], n = 136). RESULTS: The two groups of patients had similar preoperative transvalvular gradients and LVM index (130 +/- 47 vs 130 +/- 42 g/m2 for stentless versus stented valves, respectively). Predischarge echos revealed that stentless patients had significantly lower mean transvalvular gradients (11 +/- 5 vs 15 +/- 6 mm Hg, p < 0.001) and larger effective orifice areas (1.32 +/- 0.52 vs 1.22 +/- 0.48 cm2, p = 0.01). Follow-up echocardiograms were obtained in 99% of surviving patients 28 +/- 22 (range, 0-79) months postoperatively. Stentless patients had significantly lower LVM index during follow-up (100 +/- 32 vs 107 +/- 32 g/m2, p = 0.005) and stentless valves were an independent predictor of LVM regression. Furthermore, a higher proportion of stented patients had residual LV hypertrophy during follow-up (28% vs 18%, p = 0.001). Stentless valves were associated with improved midterm survival by univariate analysis, but not by multivariable analysis. CONCLUSIONS: Midterm follow-up in a large number of patients reveals that stentless bioprostheses are hemodynamically superior to stented valves.

Aortovenous bypass graft to the posterior left ventricle in absence of an identifiable coronary artery.

We report the case of a 70-year-old woman with significant intermediate coronary artery stenosis who underwent a series of stent procedures, ultimately leading to compromise of the origin of the circumflex artery. Intraoperatively, identification of an obtuse marginal coronary artery was impossible due to a thick layer of epicardial fat, calcification of the posterior atrioventricular groove, and an adherent, thickened pericardium. Therefore, a saphenous vein graft to the posterior vein of the left ventricle was constructed with ligation of the vein cephalad. This uncommon approach to surgical revascularization effectively relieved the patient's angina and may be of use in other difficult cases.

Reoperative mitral valve replacement: importance of preservation of the subvalvular apparatus.

BACKGROUND: Preservation of the subvalvular apparatus has been demonstrated to be beneficial during first-time mitral valve replacement (MVR), but has not been fully examined in reoperative (redo) MVR. The purpose of this study was to analyze outcomes in a large cohort of redo MVR patients, focusing on the effect of subvalvular preservation on mortality. METHODS: We undertook a review of prospectively gathered data on patients undergoing MVR, with or without concomitant cardiac procedures, at our institution from 1990 to 1999. Predictors of mortality were determined by stepwise logistic regression. RESULTS: A total of 1,521 consecutive MVR patients were analyzed, of which, 513 (34%) had undergone one or more previous MV procedures. In-hospital mortality occurred in 6.9% of first-time MVR patients versus 9.0% in redo patients (p = 0.13). The number of prior MV operations ranged from one to five in redo MVR patients, with 115 patients (22% of redos) having two or more. In redo MVR patients, preservation of the native posterior subvalvular apparatus was performed in 103 patients (21%), whereas native anterior and posterior preservation was performed in 31 patients (6%). Gore-Tex neochordal construction was performed in 135 redo MVR patients (26%). Perioperative mortality occurred in 3.6% of redo MVR patients with a preserved subvalvular apparatus (native tissue and/or Gore-Tex reconstruction) versus 13.3% of redo patients without preservation (p < 0.001). Independent predictors of mortality in redo MVR patients were (in decreasing order of magnitude) failure to preserve the subvalvular apparatus, preoperative renal failure, previous stroke/transient ischemic attack, left ventricular dysfunction (left ventricular ejection fraction <40%), and urgent timing. CONCLUSIONS: Redo MVR can be performed with an acceptable risk of mortality. Although preservation of the subvalvular apparatus may increase operative complexity, we recommend subvalvular preservation in order to decrease the risk of early mortality.

Prosthetic heart valves with silver-coated sewing cuff fabric: early morphological features in two patients.

BACKGROUND: The current generation of prosthetic heart valves are excellent examples of engineering that work well, for long periods of time. Unfortunately, host-related problems and consequent valve failure continue to occur, including infective endocarditis. St Jude Medical Inc introduced a new model of mechanical heart valve prosthesis with silver-treated fabric to try to reduce the incidence of infective endocarditis. Two cases of failure of this prosthesis, with a clinical diagnosis of infective endocarditis, are presented. MATERIALS AND METHODS: Of the 176 St Jude Medical Silzone-coated prostheses implanted, two were explanted in the first half of 1998. The clinical status of the patients was reviewed, and a detailed gross, histological and stereomicroscopic examination of the prosthetic valves was undertaken. RESULTS: Clinically, both patients developed symptoms of infective endocarditis. The first patient developed features of a stroke and two months later underwent a second valve replacement. The prosthesis showed pannus and thrombus. A paravalvular leak was revealed in the second patient, who underwent a second valve replacement six months after the initial surgery. Blood and tissue cultures were negative in both cases. CONCLUSIONS: The new model St Jude Medical Silzone mechanical heart valve prosthesis, designed to prevent infective endocarditis, was associated with clinical features of endocarditis in these two cases. Significant pannus and thrombus were seen on both prostheses, which likely led to emboli and stroke in the first case. The cause of the paravalvular abscess in the second case has not yet been established. The early failure of these prostheses suggests that patients with this prosthesis be followed up carefully.

We're all right Jack?

"Planning for Canada's Health Workforce: Looking Back, Looking Forward" is a readable overview that presents a pastiche of data collected by a number of organizations. The paper deals with a policy area of immense importance to the future sustainability of Canada's health system and therefore warrants attention. In the remarks that follow, we would like to amplify the following points: There is a major disconnect between the tenor of the invited essay and the profound sense of urgency in addressing the emerging shortages of health human resources (HHR) that are evident both nationally and internationally. There has been, in fact, very little progress in the comprehensive measurement of the health workforce since the 1964 Hall report. Perhaps most important, there is an absolute need to involve the practising community more in the collection and analysis of health information.