ABSTRACT
BACKGROUND: About 40% of clopidogrel-treated patients display high platelet reactivity (HPR). Alternative treatments of HPR patients, identified by platelet function tests, failed to improve their clinical outcomes in large randomized clinical trials. A more appealing alternative would be to identify HPR patients a priori, based on the presence/absence of demographic, clinical and genetic factors that affect PR. Due to the complexity and multiplicity of these factors, traditional statistical methods (TSMs) fail to identify a priori HPR patients accurately. The objective was to test whether Artificial Neural Networks (ANNs) or other Machine Learning Systems (MLSs), which use algorithms to extract model-like 'structure' information from a given set of data, accurately predict platelet reactivity (PR) in clopidogrel-treated patients. METHODS: A complete set of fifty-nine demographic, clinical, genetic data was available of 603 patients with acute coronary syndromes enrolled in the prospective GEPRESS study, which showed that HPR after 1month of clopidogrel treatment independently predicted adverse cardiovascular events in patients with Syntax Score >14. Data were analysed by MLSs and TSMs. ANNs identified more variables associated PR at 1month, compared to TSMs. RESULTS: ANNs overall accuracy in predicting PR, although superior to other MLSs was 63% (95% CI 59-66). PR phenotype changed in both directions in 35% of patients across the 3 time points tested (before PCI, at hospital discharge and at 1month). CONCLUSIONS: Despite their ability to analyse very complex non-linear phenomena, ANNs or MLS were unable to predict PR accurately, likely because PR is a highly unstable phenotype.
Subject(s)
Acute Coronary Syndrome/drug therapy , Acute Coronary Syndrome/genetics , Machine Learning , Neural Networks, Computer , Platelet Activation/drug effects , Ticlopidine/analogs & derivatives , Acute Coronary Syndrome/blood , Aged , Clopidogrel , Female , Gene Regulatory Networks/drug effects , Gene Regulatory Networks/physiology , Humans , Male , Middle Aged , Platelet Activation/physiology , Platelet Aggregation Inhibitors/pharmacology , Platelet Aggregation Inhibitors/therapeutic use , Predictive Value of Tests , Prospective Studies , Ticlopidine/pharmacology , Ticlopidine/therapeutic use , Treatment OutcomeABSTRACT
BACKGROUND: Even although time to treatment has been shown to be a determinant of mortality in primary angioplasty, the potential benefits are still unclear from early pharmacological reperfusion by glycoprotein (Gp) IIb-IIIa inhibitors. Therefore, the aim of this meta-analysis was to combine individual data from all randomized trials conducted on upstream as compared with late peri-procedural abciximab administration in primary angioplasty. METHODS: The literature was scanned using formal searches of electronic databases (MEDLINE and EMBASE) from January 1990 to December 2010. All randomized trials on upstream abciximab administration in primary angioplasty were examined. No language restrictions were enforced. RESULTS: We included a total of seven randomized trials enrolling 722 patients, who were randomized to early (n = 357, 49.4%) or late (n = 365, 50.6%) peri-procedural abciximab administration. No difference in baseline characteristics was observed between the two groups. Follow-up data were collected at a median (25th-75th percentiles) of 1095 days (720-1967). Early abciximab was associated with a significant reduction in mortality (primary endpoint) [20% vs. 24.6%; hazard ratio (HR) 95% confidence interval (CI) = 0.65 (0.42-0.98) P = 0.02, P(het) = 0.6]. Furthermore, early abciximab administration was associated with a significant improvement in pre-procedural thrombolysis in myocardial infarction (TIMI) 3 flow (21.6% vs. 10.1%, P < 0.0001), post-procedural TIMI 3 flow (90% vs. 84.8%, P = 0.04), an improvement in myocardial perfusion as evaluated by post-procedural myocardial blush grade (MBG) 3 (52.0% vs. 43.2%, P = 0.03) and ST-segment resolution (58.4% vs. 43.5%, P < 0.0001) and significantly less distal embolization (10.1% vs. 16.2%, P = 0.02). No difference was observed in terms of major bleeding complications between early and late abciximab administration (3.3% vs. 2.3%, P = 0.4). CONCLUSIONS: This meta-analysis shows that early upstream administration of abciximab in patients undergoing primary angioplasty for ST-segment elevation myocardial infarction (STEMI) is associated with significant benefits in terms of pre-procedural epicardial re-canalization and ST-segment resolution, which translates in to significant mortality benefits at long-term follow-up.
Subject(s)
Angioplasty , Antibodies, Monoclonal/therapeutic use , Immunoglobulin Fab Fragments/therapeutic use , Integrin beta3/drug effects , Platelet Aggregation Inhibitors/therapeutic use , Abciximab , Antibodies, Monoclonal/pharmacology , Humans , Immunoglobulin Fab Fragments/pharmacology , Platelet Aggregation Inhibitors/pharmacology , Randomized Controlled Trials as TopicABSTRACT
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.
Subject(s)
Aortic Valve Stenosis/surgery , Bioprosthesis , Heart Valve Prosthesis , Hemodynamics/physiology , Postoperative Complications/physiopathology , Stents , Aged , Aged, 80 and over , Aortic Valve Stenosis/physiopathology , Blood Flow Velocity/physiology , Blood Pressure/physiology , Female , Humans , Male , Prosthesis Design , Retrospective StudiesABSTRACT
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.
Subject(s)
Heart Atria/diagnostic imaging , Heart Septum/diagnostic imaging , Heart Valve Prosthesis Implantation , Mitral Valve Insufficiency/surgery , Postoperative Complications/diagnostic imaging , Surgical Wound Dehiscence/diagnostic imaging , Echocardiography, Doppler, Color , Echocardiography, Transesophageal , Heart Atria/surgery , Heart Septum/surgery , Humans , Male , Middle Aged , Mitral Valve/diagnostic imaging , Mitral Valve/surgery , Mitral Valve Insufficiency/diagnostic imaging , Postoperative Complications/surgery , Recurrence , Reoperation , Rupture, Spontaneous , Surgical Wound Dehiscence/surgery , Suture TechniquesABSTRACT
The stereochemical course of the biotransformation of 4-vinylcyclohexene (VCH, 1) by liver microsomes from male and female control and induced rats and purified rat P450 2B1 and 2E1 has been determined. The epoxidation of 1, catalyzed by male microsomes, occurs on both the endo- and exocyclic double bond to give four isomeric epoxides, cis-4-vinylcyclohexene 1,2-epoxide (2), trans-4-vinylcyclohexene 1,2-epoxide (3), (4R*,7S*)-4-vinylcyclohexene 7,8-epoxide (4), and (4R*,7R*)-4-vinylcyclohexene 7,8-epoxide (5). On the other hand, microsomes from female rats catalyzed primarily the endocyclic epoxidation. The stereoselectivity of this process was strongly dependent on gender and P450 induction. Only the phenobarbital and pyrazole, at lower levels, were able to enhance the epoxidation of 1 and mostly on the endocyclic double bond. Also, P450 2E1 and 2B1 in a reconstituted system were able to perform the epoxidation of 1 primarily on its endocyclic double bond. The metabolites, cis- and trans-4-vinylcyclohexene 1,2-epoxide (2 and 3, respectively) and the isomeric 4-vinylcyclohexene 7,8-epoxides (4 and 5), were rapidly biotransformed into the corresponding vicinal diols by mEH-catalyzed hydrolysis. The reaction of the endocyclic epoxides occurred with good substrate diastereo- and enantioselectivity favoring the hydrolysis of epoxides (1S,2R,4S)-3 and (1R,2S,4S)-2 to give, before 50% conversion, selectively (1R,2R,4S)-diol (6). At variance, the hydrolysis of the exocyclic epoxides was characterized by a high level of substrate enantioselection associated with a very low, if any, level of substrate diastereoselection, the two epoxides, (4R,7S)-4 and (4R,7R)-5, being hydrolyzed practically with the same rate. On the basis of the major resistance to mEH hydrolysis, the endocyclic epoxides, (1R,2S,4R)-3 and (1S,2R,4R)-2, are expected to be further oxidized, in a stereochemical manner, to the specific mutagenic diepoxides which are thought to play a crucial role in VCH ovotoxicity. Thus, VCH ovotoxicity may be markedly affected by the reactivity of the diepoxidic stereoisomers formed and detoxicated.
Subject(s)
Cyclohexanes/metabolism , Cytochrome P-450 CYP2B1/metabolism , Cytochrome P-450 CYP2E1/metabolism , Microsomes, Liver/enzymology , Animals , Biotransformation/physiology , Cyclohexanes/chemistry , Cyclohexenes , Epoxide Hydrolases/metabolism , Epoxy Compounds/chemistry , Epoxy Compounds/metabolism , Female , Hydrolysis , Male , Mutagens/metabolism , Oxidation-Reduction , Rats , Rats, Sprague-Dawley , Stereoisomerism , Vinyl Compounds/chemistry , Vinyl Compounds/metabolismABSTRACT
BACKGROUND: Acute-phase reactants have recently been shown to have a short-term and possibly long-term prognostic value in acute coronary syndromes. The aim of the present study was to retrospectively verify whether serum levels of inflammation markers can predict the occurrence of early and late cardiac events after myocardial infarction. METHODS: We reevaluated 58 consecutive patients (43 men and 15 women, mean age 66 +/- 12 years) admitted to our Center during 1993 with a first myocardial infarction. Patients with non-cardiac causes of inflammation were excluded, as well as patients with a left ventricular ejection fraction <40%. From the first blood sample obtained at admission, we evaluated C-reactive protein (CRP) and alpha1-acid glycoprotein (alpha1-AGP) serum levels, the erythrocyte sedimentation rate (ESR), fibrinogen levels, and the white blood cell (WBC) count. We also evaluated the highest level of serum cardiac markers. Follow-up data were collected for 55 patients in June 1999. RESULTS: Five in-hospital and 13 delayed cardiac deaths occurred. The mean follow-up of current survivors was 5.9 +/- 0.4 years. Patients in whom cardiac death occurred had significantly higher CRP (7.4 +/- 4.1 vs 3.0 +/- 2.4 mg/dl, p < 0.001) and alpha1-AGP levels (160 +/- 38 vs 113 +/- 24 mg/dl, p < 0.001), ESR (63 +/- 30 vs 37 +/- 25 mm/hour, p < 0.001), and WBC count (13,727 +/- 3,853 vs 10,936 +/- 3,358/mm3, p = 0.004). At multivariate analysis, higher alpha1-AGP (p < 0.001) and CRP serum levels (p = 0.02) were independent predictors of cardiac death. Patients in whom cardiac events occurred during follow-up showed higher CRP (5.7 +/- 3.7 vs 1.6 +/- 1.5 mg/dl, p < 0.001) and alpha1-AGP levels (140 +/- 36 vs 101 +/- 23 mg/dl, p < 0.001) and ESR (50 +/- 30 vs 34 +/- 26 mm/hour, p = 0.06). Higher alpha1-AGP (p < 0.001) and CRP serum levels (p = 0.03) were independent predictors of the occurrence of cardiac events. CONCLUSIONS: The present study shows that CRP and alpha1-AGP have an independent prognostic value in patients presenting with a first, uncomplicated myocardial infarction. Assays of these markers may help to better stratify patients hospitalized for acute coronary syndromes.
Subject(s)
Acute-Phase Proteins/analysis , Myocardial Infarction/blood , Myocardial Infarction/mortality , Aged , Female , Follow-Up Studies , Humans , Male , Middle Aged , Multivariate Analysis , Prognosis , Retrospective Studies , Survival Rate , Time FactorsABSTRACT
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.
Subject(s)
Aortic Valve Insufficiency/surgery , Aortic Valve Stenosis/surgery , Bioprosthesis , Heart Valve Prosthesis , Hemodynamics/physiology , Postoperative Complications/physiopathology , Adult , Aged , Aged, 80 and over , Aortic Valve/physiopathology , Aortic Valve/surgery , Aortic Valve Insufficiency/physiopathology , Aortic Valve Stenosis/physiopathology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prosthesis DesignABSTRACT
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
Subject(s)
Aorta/surgery , Aortic Valve/surgery , Blood Vessel Prosthesis Implantation/methods , Heart Valve Prosthesis Implantation/methods , Hemostasis, Surgical/methods , Adult , Aged , Aged, 80 and over , Anastomosis, Surgical/methods , Aortic Aneurysm/surgery , Blood Loss, Surgical , Female , Humans , Male , Middle Aged , Postoperative Complications , Suture TechniquesABSTRACT
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.
Subject(s)
Laser Therapy , Myocardial Revascularization , Aged , Angina Pectoris/etiology , Female , Humans , Length of Stay , Male , Middle Aged , Minimally Invasive Surgical Procedures , Myocardial Infarction/etiology , Myocardial Revascularization/methods , Myocardial Revascularization/mortality , Postoperative Complications , Recurrence , Stroke/etiology , Survival Rate , Time Factors , Treatment OutcomeABSTRACT
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.
Subject(s)
Mitral Valve Insufficiency/surgery , Mitral Valve/surgery , Cardiac Surgical Procedures/methods , Female , Follow-Up Studies , Heart Valve Prosthesis Implantation , Humans , Male , Middle Aged , Pericardium/transplantation , Time Factors , Transplantation, AutologousABSTRACT
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.
Subject(s)
Aortic Valve , Bioprosthesis , Heart Valve Prosthesis , Aged , Aged, 80 and over , Aortic Valve/diagnostic imaging , Body Surface Area , Cardiac Output/physiology , Echocardiography, Doppler, Color , Female , Follow-Up Studies , Heart Valve Prosthesis Implantation , Heart Ventricles/diagnostic imaging , Hemodynamics , Humans , Hypertrophy, Left Ventricular/diagnostic imaging , Male , Postoperative Complications , Prosthesis Design , Surface Properties , Survival Rate , Treatment OutcomeSubject(s)
Aortic Aneurysm, Thoracic/surgery , Aortic Valve Insufficiency/surgery , Calcinosis/surgery , Adult , Aortic Aneurysm, Thoracic/diagnostic imaging , Aortic Coarctation/surgery , Aortic Valve Insufficiency/diagnostic imaging , Calcinosis/diagnostic imaging , Cardiac Surgical Procedures/methods , Echocardiography , Follow-Up Studies , Humans , Male , Radiography , Treatment OutcomeABSTRACT
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.
Subject(s)
Embolism/diagnostic imaging , Heart Valve Prosthesis Implantation/adverse effects , Ultrasonography, Doppler, Transcranial , Adult , Aged , Aged, 80 and over , Aortic Valve/surgery , Carotid Arteries/diagnostic imaging , Embolism/etiology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Mitral Valve/surgery , Multivariate Analysis , Prospective StudiesABSTRACT
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.
Subject(s)
Aortic Valve/surgery , Exercise Test , Heart Valve Prosthesis , Hemodynamics , Pulmonary Ventilation , Aged , Anaerobic Threshold , Aortic Valve/diagnostic imaging , Body Surface Area , Echocardiography, Doppler , Exercise Tolerance , Female , Humans , Hypertrophy, Left Ventricular/diagnostic imaging , Male , Middle Aged , Prosthesis Design , Pulmonary Gas ExchangeABSTRACT
STUDY DESIGN: Case study of a basketball player who underwent an alternative surgical procedure for anterior (cruciate ligament (ACL) reconstruction and outline of the rehabilitation process designed for this procedure. OBJECTIVES: To describe the surgical procedure, detail the rehabilitation program, and report on this patient's clinical outcome. BACKGROUND: Anterior cruciate ligament injury, its treatment, and rehabilitation continue to be an area of interest to both clinicians and researchers. Surgical procedures have been refined and rehabilitation programs are constantly being evaluated and updated to allow the safest and most predictable return to activity. Currently, the autogenous bone-patellar tendon-bone graft is the graft of choice for ACL reconstruction. Typically the graft is taken from the ipsilateral knee. An alternative procedure is to take the graft from the contralateral, noninvolved knee, allowing 2 separate rehabilitation programs to take place. METHODS AND MEASURES: The patient was followed from the time of injury to 2 years postoperatively. Data collected included range of motion, isokinetic strength scores, ligament stability scores, subjective evaluation, and functional measures. RESULTS: At 3 weeks postoperative the patient had nearly full range of motion in both knees, normal gait, and was beginning sport-specific drills. He was shooting the basketball and jumping by 5 weeks and returned to competitive sports 6 weeks after surgery. He was able to play in all 32 games of the season, starting in 23 of them. CONCLUSIONS: Using the contralateral patellar tendon graft may be appropriate for primary ACL reconstruction of patients, particularly those desiring an early expedient return to athletic competition.
Subject(s)
Anterior Cruciate Ligament Injuries , Basketball/injuries , Knee Injuries/surgery , Patellar Ligament/transplantation , Physical Therapy Modalities , Adult , Anterior Cruciate Ligament/physiology , Anterior Cruciate Ligament/surgery , Basketball/physiology , Bone Transplantation/methods , Follow-Up Studies , Forecasting , Gait/physiology , Humans , Knee Injuries/rehabilitation , Knee Joint/physiology , Male , Muscle Contraction/physiology , Patient Satisfaction , Physical Therapy Modalities/methods , Range of Motion, Articular/physiology , Safety , Time Factors , Transplantation, Autologous , Treatment OutcomeABSTRACT
BACKGROUND: Transcranial Doppler sonography (TCD) of the middle cerebral arteries in patients with prosthetic heart valves reveals high-intensity transient signals (HITS) and can detect asymptomatic cerebrovascular microemboli. Both the nature of the underlying embolic material (either gaseous or corpuscular) and its clinical significance remain uncertain. METHODS: Seventy-one patients undergoing heart valve replacement (n = 63) or repair (n = 8) from June 1996 to June 1998 were prospectively evaluated preoperatively and one week, 3 months and 12 months after valve replacement using TCD. At each follow-up interval, clinical assessment was aimed at detecting neurological events. Furthermore, continuous echo-Doppler study of the carotid arteries and TCD of the middle cerebral arteries for a 30-minute period during each following visit was carried out. RESULTS: No HITS were recorded preoperatively in any patient. At one week, HITS were detected in 25 patients (35%): 22 (65%) of these had received a mechanical prosthesis and three (10%) a bioprosthesis. No HITS were recorded in patients with mitral repair. HITS were subsequently detected only in patients with mechanical prosthesis with a positive TCD at one week, the mean number of HITS per patient being 7 +/- 18 at 3 months and 8 +/- 24 at 12 months. No neurological symptoms were evident in any patients during the postoperative evaluation. Multivariate analysis showed mechanical prosthetic valve to be the only independent predictive risk factor for HITS development. CONCLUSIONS: The role of a mechanical prosthetic valve as a risk factor in the pathogenesis of HITS appears evident. However, HITS appear to be unrelated to possible postoperative neurological events. TCD could have more specific clinical applications if associated with methods that would make it possible to ascertain the nature of various embolic materials.
Subject(s)
Bioprosthesis , Heart Valve Prosthesis , Ultrasonography, Doppler, Transcranial , Aged , Aged, 80 and over , Aortic Valve , Bioprosthesis/statistics & numerical data , Female , Follow-Up Studies , Heart Valve Prosthesis/statistics & numerical data , Humans , Logistic Models , Male , Middle Aged , Mitral Valve , Prospective Studies , Risk Factors , Statistics, Nonparametric , Thromboembolism/diagnostic imaging , Time Factors , Ultrasonography, Doppler, Transcranial/instrumentation , Ultrasonography, Doppler, Transcranial/methods , Ultrasonography, Doppler, Transcranial/statistics & numerical dataABSTRACT
A 34-year-old man had development of an aortobronchial fistula 17 years after patch aortoplasty for correction of aortic coarctation and 5 years after blunt chest trauma, an unusual combination of predisposing factors. The clinical presentation, characterized by dysphonia and recurrent hemoptysis, and the surgical findings suggested the posttraumatic origin of the fistula, which was successfully managed by aortic resection and graft interposition under simple aortic cross-clamping, associated with partial pulmonary lobectomy. When hemoptysis occurs in a patient with a history of an aortic thoracic procedure, the presence of an aortobronchial fistula should be suspected. Early diagnosis offers the only possibility of recovery through a lifesaving surgical procedure.
Subject(s)
Aortic Coarctation/surgery , Aortic Diseases/etiology , Bronchial Fistula/etiology , Fistula/etiology , Postoperative Complications/etiology , Thoracic Injuries/complications , Wounds, Nonpenetrating/complications , Adult , Aorta, Thoracic/injuries , Aorta, Thoracic/surgery , Aortic Diseases/surgery , Blood Vessel Prosthesis Implantation , Bronchial Fistula/surgery , Fistula/surgery , Humans , Male , Postoperative Complications/surgery , Prosthesis Failure , Reoperation , Thoracic Injuries/surgery , Wounds, Nonpenetrating/surgeryABSTRACT
The use of bilateral internal mammary artery (BIMA) grafting for myocardial revascularization has been demonstrated to provide long-term benefits compared to revascularization using single left internal mammary artery (SIMA) and venous conduits. However, it is still controversial whether the use of BIMA is associated with a higher hospital mortality and morbidity. The present study retrospectively evaluated the possible advantages related to the use of BIMA at 3-year follow-up and whether the presence of operative risk factors in patients with BIMA could limit the application of the procedure in myocardial revascularization. We compared two groups of 100 patients matched for preoperative clinical characteristics, who underwent myocardial revascularization on the left coronary system with BIMA (93 males and 7 females, mean age 59 +/- 4 years) or with SIMA and venous conduits (86 males and 14 females, mean age 63 +/- 6 years). Hospital mortality rate was 2% in both groups, the use of BIMA being not a significant risk factor for hospital mortality and morbidity. The mean follow-up was 36 +/- 6 months for the BIMA group and 40 +/- 10 months for the SIMA group. At 3 years, there was no significant differences in the actuarial freedom from cardiac death (96 +/- 2% for BIMA vs 94 +/- 2% for SIMA patients), myocardial infarction (98 +/- 2 vs 97 +/- 2%), angina (93 +/- 2 vs 91 +/- 2%), symptomatic heart failure (92 +/- 3 vs 92 +/- 2%), coronary angioplasty/reoperation (96 +/- 2 vs 97 +/- 2% ), and total cardiac events (80 +/- 4 vs 76 +/- 4%). BIMA grafting was not an independent predictor of late cardiac events. In 66 patients who underwent a late angiographic or echo-Doppler study, the patency rate was 100% for the left mammary artery, 94% for the right mammary artery and 69% for venous conduits. In conclusion, myocardial revascularization with BIMA in situ is associated with low hospital mortality and morbidity, good clinical outcome and excellent patency rate at 3 years, with apparently no significant differences when compared to the use of SIMA and venous conduits. The low hospital mortality and morbidity and the satisfactory medium-term results in our opinion justify a more extensive use of BIMA in myocardial revascularization.