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Tirone E David

Publications and source records attributed to Tirone E David.

At least 55 records · Page 3Linked to original sources
PubMed2004

Artificial chordae.

Expanded polytetrafluoroethylene sutures have been used for replacement of chordae tendineae since 1985. They have been used for correction of prolapse of mitral and tricuspid valve leaflets as well as for resuspension of the papillary muscles during mitral valve replacement when the native chordae cannot be preserved to maintain continuity between the mitral annulus and papillary muscles. The sutures used were 5CV Gore-Tex for replacement of the chordae tendineae of the anterior leaflet and 6CV for the posterior leaflet and commissural areas of the mitral valve. Initially one suture was used to create two artificial chordae, but as experience increased, the technique was modified and multiple pairs of artificial chordae were created with a single suture by passing successively through the fibrous portions of the a papillary muscle and the free margin of the prolapsing segment of leaflet, and tying the tends together on the papillary muscle head. This technique creates artificial chordae that are interdependent and their lengths are self-adjusting when pressure is exerted on the leaflets. From 1985 to 1998, 288 patients had artificial chordae used during mitral valve repair for degenerative disease of the mitral valve. Prolapse of both leaflets was present in 51% of patients, isolated prolapse of the anterior leaflet in 28%, and posterior leaflet in 21%. The mean follow-up was 4.8 +/- 3.0 years and was complete. At 10 years, the freedom from mitral regurgitation >2+ was 88 +/- 6% and the freedom from reoperation was 92 +/- 2%. Failures of repair were unrelated to the artificial chordae. Gore-Tex sutures are an excellent material to replace chordae tendineae, appear to be free of adverse effects, and have become a valuable adjunct to the surgical armamentarium to treat mitral and tricuspid valve disease.

Adolescent↗
PubMed2004

Durability and prevalence of aortic regurgitation nine years after aortic valve replacement with the Toronto SPV stentless bioprosthesis.

BACKGROUND AND AIM OF THE STUDY: Stentless aortic bioprostheses have excellent hemodynamics. Previous investigations of the Toronto SPV valve described a correlation between the occurrence of significant aortic regurgitation (AR) and dilation of the sinotubular junction. The study aim was to determine the long-term durability and determinants of AR at nine years in a large, multicenter study of the Toronto SPV valve. METHODS: The study included 447 patients from six centers. Clinical outcomes and echocardiographic data (gradients, effective orifice area index (EOA-I), left ventricular mass, aortic root dimensions, and presence and severity of AR) were collected prospectively. A multivariable logistic regression model was used to evaluate clinical and echocardiographic variables for impact on the occurrence of AR. RESULTS: Total follow up was 2,660 patient-years (mean 6.0 +/- 2.5 years; range: 0 to 11.1 years). Mean gradient and EOA-I remained unchanged through nine years. There were 17 cases of structural deterioration, of which 15 underwent explantation. The mechanism of failure was predominantly leaflet tear in the setting of sinotubular dilation. Freedom from explant for structural failure was 90.1% at nine years (100% for patients aged > or = 65 years). Freedom from hemodynamically significant AR was 96.9% at five years and 82.5% at nine years. Determinants of AR were longer duration of follow up, larger valve size, and increase in the ratio of sinotubular junction to the size of valve implanted. CONCLUSION: At nine years after implantation of the Toronto SPV valve, hemodynamics remained excellent. There was good freedom from structural deterioration through nine years, and structural failure occurred due to aortic root dilation and leaflet tear, without significant valve calcification. AR tends to occur with longer follow up, larger valve sizes, and dilation of the sinotubular junction.

Adult↗
PubMed2004

Initial experience with the Toronto Root bioprosthesis.

BACKGROUND AND AIM OF THE STUDY: The study aim was to assess the safety and efficacy of the Toronto Root bioprosthesis for aortic root or valve replacement during the early postoperative stages. METHODS: Between November 2000 and December 2002, the Toronto Root was implanted in 191 patients in 17 institutions. The patients' mean age was 65 years (range: 25 to 87 years) and 70% were males. The bioprosthesis was implanted as a full aortic root in 76% of patients, as a root inclusion in 9%, and in the subcoronary position in 15%. The sizes used in decreasing frequency were 27, 29, 25, 23 and 21 mm. Coronary artery bypass was performed in 25% of patients. Echocardiography was performed before hospital discharge and at six months postoperatively. Serum aluminum levels were monitored pre- and postoperatively as this metal is used in anticalcification treatment of the arterial wall of the porcine root. For the purpose of this study, follow up was closed at six months in all patients, and was complete. RESULTS: Eight patients died, though none of the deaths was valve-related. Two patients required reoperation because of technical errors during implantation. Two patients developed endocarditis, one patient required surgical intervention, and two patients suffered cerebral transient ischemic attacks. All survivors experienced symptomatic improvement, and 97% were in NYHA functional classes I and II at six months postoperatively. Blood levels of aluminum were unchanged at follow up. The mean effective orifice area of all valves studied was 2.0 +/- 0.8 cm2, and the mean systolic gradient 7.0 +/- 3.9 mmHg at six months postoperatively. No patient had more than trace aortic insufficiency. CONCLUSION: Early experience with the Toronto Root bioprosthesis has shown it to be a safe and effective valve for aortic valve or aortic root replacement, with excellent hemodynamic characteristics, a low transvalvular gradient and a large effective orifice area.

Adult↗
PubMed2003

Mitral valve surgery in patients with extensive calcification of the mitral annulus.

OBJECTIVES: The objective of this work was to examine the clinical outcomes of mitral valve surgery in patients with extensive mitral annular calcification. METHODS: Mitral valve surgery was performed in 54 patients (28 men and 26 women, mean age 63 +/- 14 years) with mitral regurgitation and extensive mitral annular calcification. Most patients (78%) were in New York Heart Association classes III and IV, 14 had coronary artery disease, and 9 had prior mitral valve replacement in which the calcium bar was not removed. The calcium bar was excised and a new mitral annulus was created by suturing a strip of pericardium onto the endocardium of the left ventricle from lateral to medial fibrous trigones and to the endocardium of the left atrium. The mitral valve was repaired in 12 patients and replaced in 42. In 23 patients the intervalvular fibrous body was reconstructed and the aortic valve was also replaced. Mean follow-up was 4.1 +/- 3.7 years and was complete. RESULTS: There were 5 operative deaths and 11 late deaths. Five-year survival was 73 +/- 7%. Four patients needed reoperation and each survived. Freedom from reoperation at 5 years was 89 +/- 6%. Three patients had a stroke and 4 had anticoagulation-related hemorrhage, one of which was fatal. Five-year freedom from valve-related mortality or morbidity was 75 +/- 8%. Most survivors were in New York Heart Association functional classes II and III. CONCLUSIONS: Resection of the calcium bar and creation of a new annulus with pericardium provided good clinical results in patients with extensive calcification of the mitral valve.

Adult↗
PubMed2003

Vascular matrix remodeling in patients with bicuspid aortic valve malformations: implications for aortic dilatation.

BACKGROUND: Patients with bicuspid aortic valve malformations are at an increased risk of aortic dilatation, aneurysm formation, and dissection. Vascular tissues with deficient fibrillin-1 microfibrils release matrix metalloproteinases, enzymes that weaken the vessel wall by degrading elastic matrix components. In bicuspid aortic valve disease a deficiency of fibrillin-1 and increased matrix metalloproteinase matrix degradation might result in aortic degeneration and dilatation. METHODS: Samples of the pulmonary artery and aorta were obtained from surgical patients with bicuspid aortic valves (n = 21) and tricuspid aortic valves (n = 16). RESULTS: Fibrillin-1 content was reduced in bicuspid aortic valve aortas compared with that seen in tricuspid aortic valve aortas (P =.001), whereas the associated matrix components, elastin and collagen, were unchanged (P =.51 and P =.21). Reductions of aortic fibrillin-1 content were independent of valve function and patient age. Compared with tricuspid aortic valve aorta, matrix metalloproteinase 2 activity was increased more than 2-fold in bicuspid aortic valve aortas (P =.04) and correlated positively with aortic diameter (r = 0.74, P =.05). Matrix metalloproteinase 9 activity was not significantly different. Fibrillin-1 content was also reduced in the pulmonary arteries of patients with bicuspid aortic valves (P =.06), suggesting a systemic deficiency of fibrillin-1. Promatrix metalloproteinase 2 was increased (P =.04), reflecting an increased production of matrix metalloproteinase 2 in these fibrillin-1-deficient tissues, whereas active matrix metalloproteinase 2 and matrix metalloproteinase 9 species were unchanged, and correspondingly, the pulmonary arteries were not dilated. CONCLUSIONS: Deficient fibrillin-1 content in the vasculature of patients with bicuspid aortic valves might trigger matrix metalloproteinase production, leading to matrix disruption and dilatation. This process of vascular matrix remodeling in patients with bicuspid aortic valves offers novel therapeutic targets to prevent the aortic degeneration and dilatation characteristic of this disease.

Adult↗
PubMed2003

Tropheryma whippelii as a cause of afebrile culture-negative endocarditis: the evolving spectrum of Whipple's disease.

With the advent of molecular diagnostics culture-negative endocarditis caused by the organism Tropheryma whippelii is an increasingly described entity. We describe two patients with afebrile, culture-negative endocarditis caused by T. whippelii who had neither the gastrointestinal nor arthritic manifestations of Whipple's disease. Whipple's disease is a systemic illness caused by the organism Tropheryma whippelii and is typically characterized by diarrhea, weight loss, and arthropathy [Clin. Microbiol. Rev. 2001;14:561-583; Medicine (Baltimore) 1997;76:170-184]. Whipple's endocarditis is relatively common in autopsy studies [Can. J. Cardiol. 1996;12:831-834] but has rarely been diagnosed before death. With the advent of molecular diagnostic tools such as the polymerase chain reaction (PCR), Tropheryma whippelii as a cause of culture-negative endocarditis has become increasingly recognized [Clin. Infect. Dis. 2001;33:1309-1316; Ann. Intern. Med. 1999;131:112-116; Infection 2001;29:44-47; Ann. Intern. Med. 2000;132:595]. With this increased recognition has come the realization that Whipple's endocarditis can occur without other common manifestations of Whipple's disease [Ann. Intern. Med. 1999;131:112-116; Infection 2001;29:44-47; Ann. Intern. Med. 2000;132:595]. We report here two cases of Whipple's endocarditis without discrete febrile illness, gastrointestinal manifestations, or arthritic manifestations, diagnosed by PCR of resected valvular material.

Aged↗
PubMed2003

Late outcomes of mitral valve repair for floppy valves: Implications for asymptomatic patients.

OBJECTIVES: We sought to evaluate the long-term results of mitral valve repair in patients with mitral regurgitation caused by floppy mitral valves and compare the outcomes of asymptomatic patients with those of symptomatic patients. METHODS: A retrospective review of 488 consecutive patients who had mitral valve repair for floppy mitral valve disclosed 199 patients who were asymptomatic or had minimal symptoms and 289 patients who were symptomatic at the time of the operation. Asymptomatic patients were younger, had better ventricular function, had a lower incidence of coronary artery disease, and had higher rates of atrial fibrillation than symptomatic patients. RESULTS: Survival at 15 years was 61% for all patients. Survival was 76% for asymptomatic patients, which was identical to that for the general population matched for age and sex, whereas the survival of symptomatic patients was 53% and significantly lower than that of the general population. Cox regression analyses validated by means of bootstrap methodology identified the following predictors of late death: age by increments of 5 years (risk ratio = 1.2), New York Heart Association functional classes 3 and 4 (risk ratio = 3.0), left ventricular ejection fraction of less than 40% (risk ratio = 2.7), preoperative stroke or transient ischemic attack (risk ratio = 3.1), previous cardiac operation (risk ratio = 4.6), and severe chronic obstructive pulmonary disease (risk ratio = 3.1). Freedom from reoperation at 15 years was 91%, and it was similar for asymptomatic and symptomatic patients. Freedom from mitral regurgitation of greater than 2+ at 15 years was 85% for all patients, 96% for asymptomatic patients, and 76% for symptomatic patients. CONCLUSIONS: This study supports the recommendation of surgical intervention in asymptomatic patients with mitral regurgitation caused by a floppy mitral valve if mitral valve repair is feasible and associated with low operative mortality and morbidity.

Aged↗
PubMed2003

Results of surgery for aortic root aneurysm in patients with Marfan syndrome.

OBJECTIVES: This study was undertaken to examine the long-term results of surgery for aortic root aneurysm in patients with Marfan syndrome. METHODS: Forty-four patients underwent aortic root replacement and 61 underwent aortic valve-sparing operations for aortic root aneurysm. Patients who underwent aortic root replacement had more severe symptoms, worse left ventricular function, more severe aortic insufficiency, and larger aortic root aneurysms than did patients who had aortic valve-sparing operations. Two types of valve-sparing operations were performed: reimplantation of the aortic valve in 39 patients and remodeling of the aortic root in 22 patients. Echocardiography was performed annually during follow-up. The mean follow-ups were 75 +/- 54 months for the aortic root replacement group and 49 +/- 38 months for the aortic valve-sparing group. RESULTS: There were 1 early death and 7 late deaths; 6 deaths were in the aortic root replacement group and 2 were in the aortic valve-sparing group. Survivals at 10 years were 87% in the aortic root replacement group and 96% in the aortic valve-sparing group (P =.3). Freedoms from reoperation at 10 years were 75% in the root replacement group and 100% in the valve-sparing group (P =.1). Freedoms from valve-related mortality and morbidity were 65% after root replacement and 100% after valve-sparing operation (P =.02). Freedom from aortic insufficiency greater than 2+ after aortic valve-sparing operations was 75% at 10 years and was similar for both types of valve-sparing operations; however, the diameters of the aortic annulus and neoaortic sinuses increased only after the remodeling procedure. CONCLUSIONS: This study suggests that aortic valve-sparing operations provide similar survival but lower rates of valve-related complications than aortic root replacement for patients with Marfan syndrome. Reimplantation of the aortic valve may be more appropriate than remodeling of the aortic root to prevent dilation of the aortic annulus, and for this reason we now use only this technique to treat patients with Marfan syndrome.

Adolescent↗
PubMed2003

Mitral valve prolapse: an atypical variation of the anatomy.

BACKGROUND: The mitral valve apparatus is a complex structure composed of an annulus, mitral leaflets, chordae tendinae, papillary muscles and left ventricular, atrial and aortic walls. Deficiency or degeneration of one or more of these structures may result in dysfunction of the valvular apparatus leading to mitral valve prolapse during systole. OBJECTIVE: To review the chordal attachment of surgically resected mitral valve tissue from cases of mitral valve incompetence. METHODS: The clinical and morphological features of 135 surgically resected posterior mitral valve leaflet specimens were reviewed for mitral valve prolapse from January 1999 to June 1999. Four mitral leaflets removed either surgically or at autopsy served as controls. RESULTS: Excised posterior mitral leaflets from two patients had segments containing free margin and rough zone chordae that lacked attachment to larger 'strut' or 'stem' chordae or to either papillary muscle. These chordae were observed in otherwise normal mitral valves with adjacent areas that had normal chordal arrangements. Such chordae of the posterior leaflet were termed 'atypical chordae tendinae'. There was no good gross or histological evidence of chordal rupture, and this atypical arrangement appears to be congenital in origin. Grossly and histologically, these atypical variants otherwise exhibited characteristics similar to those of leaflet tissue from typical cases of mitral valve prolapse, with shiny, grey-white and "edematous" tissue that contained increased mucopolysaccharides in the zona spongiosa and chordae tendinae. CONCLUSIONS: This review found atypical attachment of mitral valve chordae tendinae such that isolated segments of the posterior leaflet congenitally lack chordal support, likely leading to mitral valve prolapse. Review of the literature suggests that this is a heretofore unreported cause of mitral valve incompetence.

Adult↗
PubMed2003

Aortic valve repair versus replacement in bicuspid aortic valve disease.

BACKGROUND AND AIM OF THE STUDY: The study aim was to compare the results of aortic valve repair and replacement with biological valves in adult patients with aortic insufficiency (AI) caused by congenital bicuspid aortic valve (BAV) METHODS: Forty-four patients who had aortic valve repair were matched for age and left ventricular function to 44 patients who had aortic valve replacement (AVR) with biological valves. Patients were followed annually using echocardiography. The mean follow up was 2.6 +/- 2.1 years for the repair group, and 3.5 +/- 2.1 years for the replacement group. Follow up was complete. RESULTS: There was no operative or late death in either group. Early postoperative echocardiography showed trace or no AI in 35 patients and mild AI in nine who had repair, and trace or no AI in 38 patients and mild AI in five who had AVR. The mean peak systolic gradient was 16.2 +/- 7.6 mmHg for repair and 13.2 +/- 7.2 mmHg for AVR. Four patients who had valve repair and two who had AVR, needed repeat aortic valve surgery because of progressive AI or endocarditis. Freedom from reoperation at five years was 91 +/- 5% for repair and 94 +/- 6% for replacement (p = 0.2), while freedom from moderate or severe AI at five years was 79 +/- 8% for repair and 94 +/- 6% for replacement (p = 0.024). The peak systolic gradient at follow up was 11.7 +/- 6.8 mmHg after repair and 13.3 +/- 9.6 mmHg after AVR (p = 0.4). There were no thromboembolic complications in either group. CONCLUSION: Repair of BAV is feasible in certain patients with AI, but the hemodynamics and clinical outcomes do not appear to be superior to AVR with biological valves during the first five years of follow up.

Adult↗
PubMed2002

Mitral stenosis after mitral valve repair for non-rheumatic mitral regurgitation.

BACKGROUND: Mitral stenosis after mitral valve repair for non-rheumatic mitral regurgitation is rare. METHODS: From 1990 to 1999, 478 patients had mitral valve repair for myxomatous and 40 patients had mitral valve repair for ischemic mitral regurgitation. The Carpentier annuloplasty ring (Edwards Lifesciences, Irvine, CA) was used in 72 patients, the Duran ring (Medtronic, Minneapolis, MN) in 152, a posterior band in 221 and no ring or band in 73 patients. RESULTS: Four patients developed mitral stenosis late after mitral valve repair: 2 for myxomatous disease and 2 for ischemic mitral regurgitation. All 4 patients had Duran annuloplasty rings (sizes 25 to 31). The diagnosis of mitral stenosis was made by Doppler echocardiography. The mitral valve area in these 4 patients decreased from 2.7 cm2 (range, 2.3 to 3.2 cm2) early postoperatively to 0.85 cm2 (0.4 to 1.2 cm2) after a mean follow-up of 66 months (range, 38 to 110 months). Three patients had mitral valve replacement and the etiology of the mitral stenosis was the same in all patients (ie, pannus overgrowth on the annuloplasty ring with extension onto both leaflets rendering them stiff and immobile). The fourth patient had a mitral valve area of 1.2 cm2, which was mildly symptomatic with normal pulmonary artery pressure, and this patient has not had reoperation. CONCLUSIONS: Mitral stenosis may develop after mitral valve repair for myxomatous disease or ischemic mitral regurgitation when a Duran ring is used for annuloplasty. The stenosis is caused by pannus on the annuloplasty ring with extension onto the leaflets.

Female↗