Role of circulating endothelial progenitor cells in the reparative mechanisms of stable ischemic myocardium.

BACKGROUND: Mobilization of endothelial progenitor cells (EPCs) into circulation from bone marrow in patients with acute myocardial infarction has strong scientific evidence; less is known about EPC mobilization in patients with stable coronary artery disease (CAD). The aim of this study was to investigate the association of stable ischemic heart disease with EPC levels in tissue and blood. METHODS: Fifty-five consecutive patients admitted to a single treatment center for valve or coronary artery bypass grafting (CABG) surgeries were included in the study. Blood samples were collected in the morning before surgery and analyzed by flow-cytometry to determine peripheral EPC levels (EPC/ml). Tissue EPC (CD34+VEGFR2+) levels were assessed on a right atrial appendage segment. RESULTS: Mean age was 76±5years, 48% were men, and 53% had CAD The number of CD34+ VEGFR2+ cells in the tissue of patients with CAD was significantly higher (p<0.005) and circulating EPC showed a tendency to be reduced by approximately 20% in peripheral blood of patients with CAD when compared to those without CAD. CONCLUSION: Patients with stable CAD had higher EPC density values (EPC/mm2) and were more likely to have lower EPC blood levels when compare with normal controls.

Flexible bronchoscopy during mechanical ventilation in the prone position to treat acute lung injury.

In patients with severe acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) the prone position has been shown to improve survival of patients who are severely hypoxemic with an arterial oxygen tension to inspiratory oxygen fraction ratio (PaO(2)/FiO(2))<100. In those patients tracheobronchial toilette is crucial in preventing or treating airways obstructed by secretions and deterioration of oxygenation. Flexible fiberoptic bronchoscopy is widely recognized as an effective technique to perform bronchial toilette in the intensive care unit (ICU). Flexible bronchoscopy performed during prone mechanical ventilation in two cardiosurgical patients who developed ALI after complex surgery, proved feasible and safe and helped to avoid undesirable earlier cessation of prone mechanical ventilation. However decision making about bronchoscopy in severe hypoxia should be even more cautious than in the supine patient, as dangerous delay in resuscitation manoeuvres due to postponed switching the patient to the supine position should always be prevented.

The "Mickey Mouse" aortic root: a peculiar transesophageal echo finding.

In the setting of aortic valve regurgitation, aortic valve incompetence can be caused by several mechanisms. Dilatation of a sinus of Valsalva is one possible cause of severe aortic valve regurgitation. Transesophageal echocardiography provides useful information for planning aortic root surgery by accurately describing the functional anatomy and mechanism of aortic valve dysfunction. The dilatation of a sinus of Valsalva can be easily seen in a two-dimensional short axis view of the aortic valve. When dilatation of the right sinus of Valsalva is present, the transesophageal echo view shows that the aortic root has a peculiar appearance, resembling the profile of Mickey Mouse. We suggest that a typical Mickey Mouse aspect of the aortic root, seen by transesophageal echocardiography, should prompt the recognition of dilatation of the right sinus of Valsalva as a mechanism of aortic valve dysfunction and lead to the appropriate reparative surgical technique.

Hemodynamic performance of stented and stentless aortic bioprostheses.

BACKGROUND: This study compares the hemodynamic performance of stented and stentless bioprostheses used for aortic valve replacement in patients with aortic stenosis and small aortic root. METHODS: Between 1995 and 1998, 37 patients with a 21-mm aortic annulus (group 1) underwent aortic valve replacement with either a 21-mm Edwards Perimount or a 23-mm St. Jude Toronto bioprosthesis whereas 47 patients with a 23-mm aortic annulus (group 2) received either a 23-mm Medtronic Mosaic or a 25-mm Edwards Prima bioprosthesis. In each group mean and peak gradients, effective orifice area index, and left ventricular mass index were compared during follow-up. RESULTS: Group 1 patients showed a significant reduction of mean (p < 0.001) and peak gradients (p = 0.001) during follow-up, more evident for St. Jude Toronto versus Edwards Perimount (p = 0.02 and p = 0.05, respectively). Group 2 patients showed a significant reduction of mean and peak gradients (p < 0.001), more evident for Edwards Prima versus Medtronic Mosaic (p < 0.001 and p = 0.07, respectively). Effective orifice area index significantly increased only in group 1 (p = 0.005). Left ventricular mass index significantly decreased in all patients regardless of the type of valve (p < 0.001). Patients with Edwards Prima showed a trend to a higher regression of left ventricular mass index versus Medtronic Mosaic recipients (p = 0.07). CONCLUSIONS: After aortic valve replacement, stented and stentless bioprostheses exhibited similar results with a more evident hemodynamic improvement during follow-up in the stentless valves. Stented bioprostheses of new generation, however, may parallel the hemodynamic performance of stentless valves and appear to be a valid alternative for aortic valve replacement in elderly patients with a small aortic annulus.

Dissection of atrial septum after mitral valve replacement.

We report a patient who presented with paraprosthetic leak complicated by dissection of the interatrial septum after mitral valve replacement. A review of the literature provides confirmation that only 3 cases have been previously reported of this potential, albeit extremely rare, complication of prosthetic mitral valve replacement. Prosthesis oversizing and improper mitral annular handling appeared to be the predisposing factors of this complication.

Hemodynamic assessment of the Medtronic Mosaic bioprosthesis in the aortic position.

BACKGROUND AND AIM OF THE STUDY: The Medtronic Mosaic bioprosthesis (MMB) is a newly developed tissue valve which incorporates several features such as a low-profile semi-flexible stent, zero-pressure tissue fixation, and anti-mineralization pretreatment with alpha-amino oleic acid aimed to improve hemodynamics and prevent structural deterioration. METHODS: Between November 1995 to June 1999, 62 patients underwent aortic valve replacement (AVR) with the MMB; 41 of these who reached the one-year follow up interval and who had isolated AVR without any concomitant procedure with size 23 mm and 25 mm MMB were evaluated by serial echocardiography after three, six and 12 months. RESULTS: For size 23 mm valves, mean and peak gradients were 12+/-3 and 21+/-6 mmHg at 3 months, 12+/-3 and 20+/-5 mmHg at 6 months, and 12+/-4 and 20+/-6 mmHg at 12 months. For size 25 mm valves, mean and peak gradients were 13+/-2 and 22+/-4 mmHg at 3 months, 12+/-3 and 21+/-5 mmHg at 6 months, and 12+/-4 and 22+/-6 mmHg at 12 months. In patients with 23 mm MMB, left ventricular mass index (LVMi) was reduced from 181+/-34 g/m2 before surgery to 158+/-32, 150+/-28 and 140+/-25 g/m2 at 3, 6 and 12 months after AVR (p <0.001); in patients with 25 mm MMB, LVMi was reduced from 182+/-28 g/m2 before surgery to 165+/-25, 156+/-24 and 146+/-19 g/m2 at 3, 6 and 12 months after AVR (p <0.001). CONCLUSION: Our results indicate that MMB is associated with low mean and peak gradients and significant reduction in LVMi throughout the postoperative period. Thus, the MMB appears to be an excellent cardiac valve substitute in elderly subjects who require AVR.

Evaluation of valve-related complications in patients with Sorin Bicarbon prosthesis: a seven-year experience.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the medium-term results of aortic valve replacement (AVR), mitral valve replacement (MVR) and double valve replacement (DVR) with the Sorin Bicarbon prosthesis. METHODS: A total of 990 patients (568 men, 422 women; mean age 60+/-10 years; range: 20-86 years) was reviewed who received 1,108 Sorin Bicarbon prostheses between 1992 and 1998 at three institutions. AVR was performed in 541 patients (55%), MVR in 330 (33%) and DVR in 119 (12%). Concomitant procedures, mainly coronary artery grafting, were performed in 222 patients (22%). Follow up was 98% complete; total cumulative follow up was 3,091 patient-years. RESULTS: Hospital mortality was 3.7% (n = 37). There were 49 late deaths; actuarial survival at seven years was 88+/-2% after AVR, 86+/-5% after MVR, and 78+/-8% after DVR. At last follow up, 915 survivors were in NYHA functional class I or II. At seven years, actuarial freedom from valve-related deaths, valve thrombosis, embolism and bleeding respectively was 96+/-1%, 99+/-1%, 93+/-2% and 91+/-3% after AVR; 97+/-2%, 97+/-3%, 90+/-3% and 86+/-7% after MVR; and 92+/-6%, 98+/-1%, 64+/-2% and 82+/-2% after DVR. Reoperation was required in 20 patients (due to valve thrombosis in six, endocarditis in five and periprosthetic leak in nine). At seven years, actuarial freedom from reoperation was 97+/-1%, 96+/-2% and 84+/-9% after AVR, MVR and DVR, respectively; actuarial freedom from endocarditis was 99+/-1%, 99+/-1% and 95+/-5%. Nine patients experienced a nonstructural valve dysfunction (all periprosthetic leak), while no cases of structural failure were observed. CONCLUSION: The Sorin Bicarbon prosthesis has shown good medium-term results with regard to clinical improvement, and low incidence of valve-related complications. Thus, it appears to be a reliable valve substitute when the use of a mechanical prosthesis is indicated.

Improving hemostasis during replacement of the ascending aorta and aortic valve with a composite graft.

The use of a composite graft is an established treatment for patients with aortic valve disease and ascending aortic aneurysms. Since bleeding from suture lines is a potential complication of this procedure, we modified the technique and evaluated the effect on hemostasis. From January 1994 through December 1998, 35 patients underwent composite aortic graft replacement for chronic aortic disease. In the first 16 patients (Group 1), we used the standard open technique, with excision of the aortic aneurysm and anastomosis of aortic buttons containing the coronary ostia to the vascular graft. In the next 19 patients (Group 2), we modified the technique by placing an additional suture at the proximal graft anastomosis and harvesting large coronary buttons that were then attached to the graft by an "endo-button" buttress method. There were no operative deaths; the actuarial survival rate at 36 months was 92% +/- 5%. Between groups 1 and 2, a significant difference was found in postoperative bleeding (1,052 + 433 mL vs 806 +/- 257 mL, respectively; p = 0.02) and in number of blood transfusions required (2.1 +/- 2.0 units vs 0.4 +/- 0.7 units, respectively; p = 0.002). Multivariate analysis showed that the surgical technique used in Group 1 was the only independent risk factor for postoperative bleeding of 1,000 mL or more (p = 0.01) and for transfusion requirements of 3 or more units of blood (p = 0.004). Composite aortic valve and root replacement can be accomplished with excellent results. Technical modifications may reduce bleeding complications and related morbidity significantly

Symptomatic improvement after transmyocardial laser revascularization: how long does it last?

BACKGROUND: The aim of this study was to determine whether short-term clinical improvement after isolated transmyocardial holmium laser revascularization (TMLR) in patients with coronary artery disease not amenable to traditional treatment is maintained through a longer follow-up. METHODS: Between November 1995 and June 1999 34 patients underwent TMLR (mean age, 67+/-7 years); previous revascularization procedures had been performed in 76%. Preoperatively, mean angina class was 3.6+/-0.5 in 12 patients with unstable angina; mean left ventricular ejection fraction was 47%+/-9%. RESULTS: There was 1 early death due to low cardiac output. Mean duration of TMLR and of the entire operation was 25+/-12 minutes and 125+/-43 minutes, respectively. There were no major postoperative complications; mean hospital stay was 8+/-4 days. There were 8 late deaths caused by stroke (2 patients), cardiac failure (1 patient), and myocardial infarction (5 patients). Follow-up of current survivors ranges from 4 to 48 months (mean, 32+/-12 months). At 1-year follow-up mean angina class was 1.8+/-0.8; but at a later follow-up (mean, 35+/-10 months) it significantly increased to 2.2+/-0.7 (p = 0.005). Three-year actuarial survival was 76%+/-8% and freedom from cardiac events 44%+/-10%. CONCLUSIONS: Our results show that after initial clinical improvement many patients experience return of angina or cardiac events; this questions the long-term symptomatic benefit of TMLR.

Concomitant aortic valve replacement and surgical angioplasty of left main coronary ostium.

The association of calcific aortic valve disease and isolated coronary ostial stenosis is rare. A 80-year-old woman was found to have severe aortic stenosis with critical narrowing of the ostium of the left main coronary artery. She was successfully managed by simultaneous aortic valve replacement and patch angioplasty of the left main coronary artery, using a patch of autologous pericardium fixed in glutaraldehyde. Angiographic control at 1 month coupled with intravascular echographic imaging showed adequate relief of the ostial stenosis and patency of the left main trunk.

Mitral valve annuloplasty for degenerative disease: assessment of four different techniques.

BACKGROUND AND AIM OF THE STUDY: Mitral valve repair (MVR) is the treatment of choice in patients with degenerative valve disease. However, controversy persists as to whether mitral valve annuloplasty should always be included as part of the reconstructive procedure. METHODS: The records of 62 consecutive patients undergoing MVR for degenerative disease between January 1994 and December 1996 were reviewed. Four different annuloplasty techniques were associated with various MVR procedures: local posterior annuloplasty (group 1, n = 10), rigid Carpentier ring (group 2, n = 20), Duran ring (group 3, n = 17), and posterior annular plication with autologous pericardium (group 4, n = 15). The four patient groups were similar in terms of preoperative clinical and echocardiographic characteristics. Serial clinical and echocardiographic follow up was performed to assess functional status and stability of repair. RESULTS: There were no early or late deaths. Mean follow up in the entire patient series was 31 +/- 12 months. One patient in group 2 required reoperation 14 months after MVR. In all groups there was a significant improvement in NYHA functional class (from 2.7 +/- 0.6 to 0.9 +/- 0.5, p <0.001), with a reduction of left ventricular end-diastolic and end-systolic volumes (154 +/- 50 ml to 105 +/- 33 ml, p <0.001; and 64 +/- 23 ml to 52 +/- 22 ml, p <0.001). In patients of groups 2, 3 and 4, residual mitral incompetence at follow up (0.8 +/- 0.9 in group 2, 0.8 +/- 0.7 in group 3, and 0.2 +/- 0.6 in group 4) was not significantly different from discharge. However, in group 1, a higher degree of residual mitral regurgitation was present at discharge (0.9 +/- 0.6) with a trend to progress at follow up (1.6 +/- 0.5). CONCLUSION: In patients with degenerative mitral valve disease, MVR provides clinical and functional improvement. Techniques of stabilization of the entire posterior mitral annulus achieve better early and medium-term results, and should be always considered as part of MVR. Autologous pericardium appears to be an excellent annuloplasty material, though its apparent superiority over synthetic rings must be confirmed at longer follow up.

Performance of 21-mm size perimount aortic bioprosthesis in the elderly.

BACKGROUND: Aortic valve replacement in elderly patients with a small aortic annulus may pose difficult problems in terms of prosthesis selection. We have evaluated the hemodynamic performance of the 21-mm Carpentier-Edwards Perimount bioprosthesis implanted in elderly patients. METHODS: From July 1996 to June 1998, 19 patients (17 women and 2 men, mean age 76+/-4 years and mean body surface area 1.73+/-0.13 m2), had aortic valve replacement with a 21-mm Carpentier-Edwards Perimount bioprosthesis. The hemodynamic performance of the valve was evaluated in 16 patients, who completed at least a 6-month follow-up interval, with transthoracic color-Doppler echocardiography with particular reference to peak and mean transprosthetic gradients, effective orifice area index, and regression of left ventricular mass index. RESULTS: There were no late deaths and no major postoperative complications. At a mean follow-up of 12+/-7 months, compared to discharge, all patients showed clinical improvement with a significant reduction of peak gradient (from 23+/-4 to 21+/-6 mm Hg, p = 0.04) and left ventricular mass index (from 181+/-23 to 153+/-20 g/m2; p<0.001), whereas mean gradient (from 13+/-3 to 13+/-4 mm Hg, p = not significant) and effective orifice area index (from 1.12+/-0.34 to 1.13+/-0.28 cm2/m2, p = not significant) remained substantially unchanged. CONCLUSIONS: The use of a 21-mm Carpentier-Edwards Perimount bioprosthesis is associated with low transprosthetic gradients and significant reduction in left ventricular hypertrophy after aortic valve replacement. The results of our study suggest that a 21-m Carpentier-Edwards Perimount bioprosthesis should be considered a valid option in elderly patients with aortic valve disease and a small aortic annulus.

Prospective evaluation of frequency and nature of transcranial high-intensity Doppler signals in prosthetic valve recipients.

BACKGROUND AND AIM OF THE STUDY: In asymptomatic prosthetic valve recipients, high-intensity transient signals (HITS) observed with transcranial Doppler (TCD) are a phenomenon of obscure clinical relevance which nature has not yet been elucidated convincingly. METHODS: Eighty-three patients without carotid disease, history of cerebrovascular accidents, and with negative preoperative TCD undergoing either valve replacement (mitral, n = 11; aortic, n = 56; mitral + aortic, n = 6; 40 mechanical prostheses, 29 biological prostheses, 10 homografts) or mitral repair (n = 10) were evaluated prospectively by means of TCD at discharge, three months and one year after surgery, to analyze the presence, incidence and characteristics of HITS. Furthermore, in 12 patients positive for HITS, TCD was repeated during a 30-min period of 100% O2 inhalation. RESULTS: Twenty-five patients (30%) were positive for HITS at all postoperative controls, although no neurological symptoms were observed. Mechanical prostheses showed a significantly higher incidence of HITS (85%) than biological prostheses (10%, p <0.001), repaired mitral valves (0%, p <0.001) and homografts (0%, p <0.001). At multivariate analysis the presence of a mechanical prosthesis was the only significant predictor of detection of HITS after valve replacement. During O2 inhalation, a significant decrease in the number of HITS per hour (55 +/- 79 versus 22 +/- 31, p = 0.002) occurred, which returned to initial values when room-air breathing was resumed. CONCLUSIONS: Prosthetic valve replacement, particularly when mechanical devices are used, is associated with the generation of HITS which persist throughout the follow up period, but remain clinically silent. The decrease of HITS during O2 inhalation strongly supports the hypothesis of the gaseous nature of such signals and confirms the validity of this method in helping to differentiate gaseous microemboli from solid microemboli in prosthetic valve recipients.

Cardiopulmonary exercise testing in patients with 21mm St. Jude Medical aortic prosthesis.

BACKGROUND AND AIM OF THE STUDY: Small-sized prostheses may be associated with high transprosthetic gradients, particularly in patients with a body surface area (BSA) >1.70m2, affecting left ventricular mass regression, symptom improvement and long-term survival. However, the influence of such gradients on exercise tolerance has not been clearly defined. The study aim was to verify the utility of cardiopulmonary exercise testing (CPX) in detecting patient-prosthesis mismatch, and to identify the clinical and echocardiographic data that predict exercise tolerance at CPX in patients with a 21mm St. Jude Medical (SJM) aortic prosthesis. METHODS: Twenty patients (one male, 19 females; mean age 66 +/- 9 years) with a 21 mm SJM prosthesis were evaluated by means of 2D echocardiography and CPX at 36 +/- 10 months after operation. Patients were divided into groups on the basis of a BSA of <1.70 m2 (group 1, n = 12) or > or =1.70 m2 (group 2, n = 8). RESULTS: At echocardiography, left ventricular mass reduction was 16 +/- 10% versus 9 +/- 6% in groups 1 and 2, respectively, mean gradient (MG) was 15 +/- 6 versus 17 +/- 4 mmHg (p = NS), effective orifice area index (EOAi) 0.86 +/- 0.10 versus 0.79 +/- 0.09 cm2/m2 (p = 0.05). At CPX, group 2 patients showed a significantly lower exercise duration (p = 0.02), maximum workload (p = 0.02), peak O2 uptake (p = 0.01), anaerobic threshold (AT) (p = 0.03), ventilatory equivalent for CO2 at AT (p = 0.007), and O2 cost of work (p = 0.03). Group 1 patients showed a ventilatory origin for their effort dyspnea, while group 2 patients showed a significant circulatory component. At multivariate analysis, BSA, age, EOAi and MG were independent predictors of CPX results. CONCLUSIONS: In patients with a 21 mm aortic SJM prosthesis and a BSA > or =1.70m2, CPX allows detection of patient-prosthesis mismatch, in terms of impaired exercise tolerance due to circulatory causes. CPX results can be anticipated on the basis of the patient's BSA, age, EOAi and MG. In these patients, technical solutions allowing implantation of a larger prosthesis should be considered whenever an active lifestyle is anticipated after aortic valve replacement.