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Biomedical subjects

Sandra Braun

Publications and source records attributed to Sandra Braun.

17 recordsLinked to original sources
PubMed2006

[Brain natriuretic peptide in primary pulmonary hypertension].

BACKGROUND: Primary pulmonary hypertension (PPH) is a progressive disease leading to right heart failure and death. Right heart catherization and maximal or submaximal tests are employed to assess the course of the disease. A neurohormonal parameter such as pro-brain natriuretic peptide (BNP) would be helpful in the assessment of these patients. AIM: To study the correlation of BNP with functional status and non-invasive hemodynamic determinations in patients with PPH. MATERIAL AND METHODS: Twelve patients (mean age: 48 years; 58% female) were evaluated with 6 minutes walk distance test (6-min WT), plasma BNP, systolic pulmonary artery pressure (PAP), pulmonary vascular resistance (PVR) and cardiac output (CO) determined by echocardiogram. Plasma BNP levels were compared with normal subjects. RESULTS: BNP levels were increased in PPH patients (1270+/-547 vs 48+/-8 pg/ml, p-value <0.01). Mean PAPs was 82+/-27 mmHg and the mean distance walked in 6 minutes was 407+/-113 meters. BNP levels were positively correlated with PVR (r=0.58, p-value=0.006) and negatively correlated with 6-min WT (r=-0.83, p-value <0.001). No correlation was found between BNP levels, PAPs and CO. CONCLUSIONS: In PPH patients, BNP levels are increased and correlate with functional class and PVR. Follow-up studies are needed to evaluate the role of BNP as a marker of progression and therapeutic response in PPH patients.

Biomarkers↗
PubMed2006

Amino acid variants in Surfactant protein D are not associated with bronchial asthma.

Surfactant protein D (SFTPD) belongs to the family of collectins and is part of the innate immune system. Thereby it plays an important role in the defense of various pathogens. Besides it is involved in the development of acute and chronic inflammation of the lung. Levels of SFTPD are elevated in serum and alveolar lavage of asthmatic patients. As SFTPD binds and neutralizes common allergens like house dust mites it is especially important in allergic asthma. Three common amino acid variants have been identified in SFTPD and association of the first variant has been described to severe infection with respiratory syncytial virus. Furthermore the functional impact of all three amino acid variants has been demonstrated. Due to its function SFTPD represents an ideal candidate gene for bronchial asthma and we were interested whether the polymorphisms were in association with asthma in children. The three polymorphisms leading to amino acid exchanges (Met11Thr, Ala160Thr, and Ser270 Thr) were typed by restriction fragment length polymorphisms in 322 asthmatic children and 270 controls. Association analyses were performed by Armitage's trend test. In addition haplotypes were calculated by FASTEHPLUS and FAMHAP. None of the polymorphisms was in association with bronchial asthma. Haplotype analyses revealed four major haplotypes all of which were evenly distributed between the populations. We conclude from our data that functional amino acid variants in SFTPD do not play a major role in the genetic pre-disposition to bronchial asthma in children.

Adolescent↗
PubMed2005

[Long-term results of repair versus replacement for degenerative mitral valve regurgitation].

BACKGROUND: Mitral valve repair is considered better than mitral valve replacement for degenerative mitral regurgitation. AIM: To evaluate late clinical results of mitral valve repair as compared to mitral valve replacement in patients with degenerative mitral regurgitation. PATIENTS AND METHODS: All patients subjected to open heart surgery for degenerative mitral regurgitation between 1990 and 2002 were assessed for surgical mortality, late cardiac and overall mortality, reoperation, readmission to hospital, functional capacity and anticoagulant therapy. Eighty eight patients (48 males) had mitral valve repair and 28 (19 males) had mitral valve replacement (23 with a mechanical prosthesis). Mean age was 59.9 +/- 14.8 (SD) and 61.3 +/- 14.6 years, respectively. Sixty three percent of patients with repair and 50% of those with valve replacement were in functional class III or IV before surgery. RESULTS: Operative mortality was 2.3% for mitral valve repair and 3.6% for mitral valve replacement (NS). Also, there was no statistical difference in the need of reoperation during the follow-up period between both procedures (2.3% and 0%, respectively). Ninety four percent of the replacement patients but only 26% of the repair patients were in anticoagulant therapy at the end of the follow-up period (p < 0.001). Ten years survival rates were 82 +/- 6% for mitral valve repair and 54 +/- 11% for replacement. The corresponding cardiac related survival rates were 89 +/- 6% and 79 +/- 10%. At the end of follow-up, all surviving patients were in functional class I or II. Ten years freedom from cardiac event rates (death, cardiac related rehospitalization and reoperation) were 90 +/- 3% for mitral valve repair and 84 +/- 6% for replacement. CONCLUSION: Repair of the mitral valve offers a better overall survival and a better chance of freedom from cardiac events as well as need for anticoagulation 10 years after surgery.

Adolescent↗
PubMed2005

C-reactive protein and atrial fibrillation: "evidence for the presence of inflammation in the perpetuation of the arrhythmia".

BACKGROUND: Atrial fibrillation (AF) is associated to a high risk of systemic embolism. The mechanisms that contribute to thrombogenesis in these patients are still poorly understood. Systemic and/or local inflammation could be involved in the process of thrombogenesis and contribute to the perpetuation of the arrhythmia. The purpose of the study was to evaluate the role of inflammation and its relation to thrombogenesis and cardiac rhythm in AF. METHODS: We prospectively studied 130 patients with newly diagnosed non-valvular AF in absence of antithrombotic therapy. Determinations of C-reactive protein (CRP) and thrombin-antithrombin complex (TAT) plasma levels, along with a transesophageal echocardiogram were performed in all the patients at admission. RESULTS: Mean age of the group was 67+/-14 years. CRP levels were significantly elevated in AF patients versus controls (matched by age, gender and cardiovascular risk factors) (1.0+/-1.8 versus 0.3+/-0.4 mg/dl, respectively, p<0.01). Baseline TAT levels were also significantly elevated in AF patients but no correlation was found between CRP and TAT. At 1-year of follow-up, mean CRP levels were still elevated in patients that remained in AF compared to those who converted to sinus rhythm (1.2+/-1.8 compared to 0.5+/-1.5 mg/dl, p=0.03). CRP was the only biochemical predictor of sinus rhythm maintenance at 1-year follow-up independently of clinical (including adjustment for risk factors and antiarrhythmic drugs), biochemical and echo parameters. CONCLUSIONS: There is evidence for the presence of inflammation in patients with non-valvular AF, which is not related to activation of the coagulation cascade. The persistence of inflammation is associated with chronic AF at 1-year follow up.

Aged↗
PubMed2005

[Valve repair surgery for incompetent bicuspid aortic valves].

BACKGROUND: Surgical valve repair is a good alternative for correction of incompetent bicuspid aortic valve. AIM: To report the early and late surgical, clinical and ecochardiographic results of surgical repair of incompetent bicuspid aortic valves. PATIENTS AND METHODS: Retrospective review of medical records of 18 patients aged 19 to 61 years, with incompetent bicuspid aortic valve in whom a valve repair was performed. Four patients had infectious endocarditis and 17 were in functional class I or II. Follow up ranged from 3 to 113 months after surgery. RESULTS: A triangular resection of the prolapsing larger cusp, which included the middle raphe, was performed in 17 cases; in 13 of these, a complementary subcommisural annuloplasty was performed. In the remaining case, with a perforation of the non-coronary cusp, a pericardial patch was implanted; this procedure was also performed in 2 other cases. In 3 cases large vegetations were removed. Postoperative transesophageal echocardiography showed no regurgitation in 11 patients (62%) and mild regurgitation in 7 (38%). There was no operative morbidity or mortality. There were no deaths during the follow-up period. In 3 patients (17%) the aortic valve was replaced with a mechanical prosthesis, 8 to 108 months after the first operation. Reoperation was not needed in 93%+/-6,4% at 1 year and 85%+/-9,5% at 5 years, these patients were all in functional class I at the end of the follow-up period. 60% had no aortic regurgitation, 20% had mild and 20% moderate aortic regurgitation on echocardiographic examination. A significant reduction of the diastolic diameter of the left ventricle was observed, but there were no significant changes in systolic diameter or shortening fraction. CONCLUSIONS: Surgical repair of incompetent bicuspid aortic valves has low operative morbidity and mortality and has a low risk of reoperation.

Adult↗
PubMed2004

Multilocus haplotype analyses reveal association between 5 novel IL-15 polymorphisms and asthma.

BACKGROUND: IL-15 is a T(H)1-related cytokine that is involved in the inflammatory response in various infectious and autoimmune diseases. IL-15 has recently been shown to be upregulated in T-cell-mediated inflammatory disorders. The observations suggest a potential role for this cytokine in a variety of pathologic conditions, including T(H)1-mediated and T(H)2-mediated inflammatory diseases. OBJECTIVE: In this study, we searched for single nucleotide polymorphisms in the whole IL-15 gene and investigated their association with inflammatory and/or atopic phenotypes. METHODS: The screening for single nucleotide polymorphisms was performed by single-strand conformation polymorphism analysis. Genotyping of the identified polymorphisms was performed by restriction fragment length polymorphism. Genotypic association analysis used the Armitage trend test. Haplotype frequency estimation and subsequent testing for differences between cases and controls were performed by using the programs FASTEHPLUS and FAMHAP. RESULTS: We identified 5 novel noncoding nucleotide sequence variants, all of which were typed in our asthmatic, our atopic, and our control population. According to the Armitage trend test, none of the 5 polymorphisms is associated with the phenotype bronchial asthma or atopy. However, multilocus haplotype analysis based on simulations to find out whether the haplotype frequencies differed between cases and controls by using the program FAMHAP yielded a P value of 6.1 x 10(-5) in the asthmatic versus the control population, which is highly significant. Furthermore, we obtained a nominally significant result of P=.0232 for the atopic versus the control population by using FAMHAP. CONCLUSION: These results strongly underscore previous findings that suggest a potential role of this cytokine in allergic diseases.

Adolescent↗
PubMed2004

[Valve repair surgery in infectious endocarditis].

BACKGROUND: Valve replacement has been the treatment of choice for patients with valvular complications of infectious endocarditis (IE). However, excellent results with valve repair allowed it to become a new therapeutic alternative for these patients. AIM: To evaluate the results of valve repair in patients with valvular complications of IE. PATIENTS AND METHODS: From January 1991 to December 2000, 14 patients with valvular complications of IE underwent valve repair. Mean age was 37.9 +/- 14.9. RESULTS: New York Heart Association (NYHA) class was 2.8 +/- 0.9. IE was located in the aortic in 6 (42%), in the mitral valve in 4 (29%) and in both valves in 4 cases (29%). Surgical indication was hemodynamic in 50% of the cases, echocardiographic in 29% and septic in 21%. Five aortic valves were bicuspid, 3 mitral valves were myxomatous and the rest were normal. The most common septic lesions were vegetations and leaflet perforations. A total of 23 aortic and 21 mitral valve repair procedures were performed. There were no deaths. Only 1 patient had a surgical complication (renal failure and prolonged mechanical ventilation). Follow-up was 100% complete. There was not late mortality. One patient with bone marrow aplasia required reoperation for a new episode of IE 19 months later. At the end of the follow-up NYHA class was 1.3 +/- 0.6 and echocardiography showed a mild or absence of valve regurgitation in most patients. CONCLUSIONS: Valve repair surgery in IE has good results, with advantages over valve replacement.

Adolescent↗
PubMed2003

Mediation of corticotropin releasing factor type 1 receptor phosphorylation and desensitization by protein kinase C: a possible role in stress adaptation.

Protein kinase C (PKC)-mediated desensitization of the corticotropin releasing factor type 1 (CRF1) receptor was investigated in human retinoblastoma Y79 and transfected COS-7 cells. Because stimulation of Y79 cells with CRF resulted in large ( approximately 30-fold) increases in intracellular cAMP accumulation without changing inositol phosphate levels, the CRF1 receptor expressed in retinoblastoma cells couples to Gs, but not to Gq, and predominantly signals via the protein kinase A cascade. Direct activation of PKC by treatment with the phorbol ester phorbol 12-myristate 13-acetate (PMA) or 1,2-dioctanoyl-sn-glycerol (DOG) desensitized CRF1 receptors in Y79 cells, reducing the maximum for CRF- (but not forskolin)-stimulated cAMP accumulation by 56.3 +/- 1.2% and 40.4 +/- 2.1%, respectively (p < 0.001). Pretreating Y79 cells with the PKC inhibitor bisindolylmaleimide I (BIM) markedly inhibited PMA's desensitizing action on CRF-stimulated cAMP accumulation, but did not affect homologous CRF1 receptor desensitization. Retinoblastoma cells were found to express PKCalpha, betaI, betaII, delta, lambda, and RACK1. When alpha and beta isoforms of PKC were down-regulated 80 to 90% by a 48-h PMA exposure, PMA-induced CRF1 receptor desensitization was abolished. In transfected COS-7 cells the magnitude of CRF1 receptor phosphorylation after a 5-min exposure to PMA was 2.32 +/- 0.21-fold greater compared with the basal level. Pretreating COS-7 cells with BIM abolished PMA-induced CRF1 receptor phosphorylation. These studies demonstrate that protein kinase C (possibly alpha and beta isoforms) has an important role in the phosphorylation and heterologous desensitization of the CRF1 receptor.

Acclimatization↗
PubMed2003

[Infectious endocarditis: morbi-mortality in Chile. Results of the National Cooperative Study of Infective Endocarditis (1998-2002)].

BACKGROUND: Infective endocarditis is a severe condition, with a mortality that fluctuates between 16 and 25% in the Metropolitan area of Chile. AIM: To perform a prospective assessment of clinical and microbiological features of patients with infective endocarditis in Chile. MATERIAL AND METHODS: Collaborative study of regional hospitals in the whole country and teaching hospitals in Santiago. Patients with a possible or definitive infective endocarditis, according to Duke's criteria, were included in the protocol and a structured data entry form was completed. RESULTS: Three hundred twenty one patients (65% male, mean age 49 +/- 16.5 years) were studied. According Duke's criteria, 89% had a definitive and 11% a possible endocarditis. The subacute form occurred in 64% of patients. The most frequent predisposing cardiopathies were rheumatic in 25%, prosthetic valves in 15% and congenital in 13%. There was no evidence of cardiopathy in 20%. Twenty percent of patients were on hemodialysis, 11% were diabetic and only one patient abused intravenous drugs. The most frequent complication was cardiac failure in 59% of cases, followed by renal failure in 32% and embolism in 28%. The most frequent causing organism was coagulase positive Staphylococcus in 35%. Blood cultures were negative in 28% of cases from the metropolitan region, in 56% of cases from the north and 38% of cases from the south. Echocardiographic diagnosis was done in 92% of cases. Aortic valve was involved in 42% and mitral valve in 29%. Successful antimicrobial treatment was achieved in 59% of patients. Thirty five percent of patients were subjected to surgical procedures with a 78% survival. Overall mortality was 29%. Univariate analysis identified sepsis, an age over 60 years and the presence of cardiac or renal failure as prognostic indicators of mortality. On multivariate analysis, the identified prognostic indicators were the presence of sepsis, renal failure, mitroaortic involvement associated to combined surgery and failure of antimicrobial treatment not associated to surgery. CONCLUSIONS: Subacute form is the most common presentation of infective endocarditis and rheumatic valve disease is the most common underlying cardiac lesion. Intravenous drugs users infective endocarditis is exceptional in Chile. The most frequent causing agent is coagulase positive Staphylococcus and the most frequent complication is cardiac failure. Surgical and overall mortality were 22 and 29% respectively. Sepsis, renal failure, combined surgical procedures, failure of medical treatment were identified as prognostic indicators of mortality.

Adolescent↗
PubMed2003

[Long-term results of repair surgery of degenerative mitral insufficiency].

BACKGROUND: Mitral valve repair is probably the procedure of choice for the surgical treatment of degenerative mitral insufficiency. AIM: To evaluate the late results of mitral valve repair in degenerative mitral insufficiency. PATIENTS AND METHOD: The records of 88 patients who underwent mitral valve repair for degenerative mitral insufficiency from December 1991 through June 2002 were reviewed. Mean age was 59.9 years (range 22 to 82). At least moderate mitral insufficiency was present in every patient. Mean left atrial diameter was 55 mm and mean end diastolic and end systolic left ventricular diameters were 61 and 37 mm respectively. RESULTS: The most common underlying lesion was ruptured chordae tendineae (66%) and posterior leaflet prolapse (68%). The surgical procedure most frequently performed was quadrilateral resection of the posterior leaflet (68%). A Carpentier-Edwards ring was placed in 97% of patients. An associated procedure was performed in 34%. Operative mortality was 2.3%. A complete follow up was obtained in 93% of cases with a mean of 54 +/- 36 months. Overall survival rate was 98% at one year, 88% at 5 and 82% at 10 years. Free of cardiac death rates were 94% at 5 and 89% at 10 years. Only 2 patients were reoperated during follow up, resulting in a 98% reoperation free rate follow up. Functional class improved in all patients at the end of follow up. Late echocardiographic evaluation showed absent or minimal mitral regurgitation in 83% and mild mitral regurgitation in 17%. CONCLUSION: Good late results have been obtained with mitral valve repair, avoiding the inconveniences of prosthetic replacement. Therefore, mitral valve repair should be the procedure of choice to treat degenerative mitral insufficiency.

Adult↗
PubMed2002

GRK3 regulation during CRF- and urocortin-induced CRF1 receptor desensitization.

The EC(50) values for concentration-dependent stimulation of cAMP accumulation by CRF (1.3nM) and urocortin (1.0nM) were equivalent in human retinoblastoma Y79 cells. The time course and magnitude of CRF- and urocortin-induced CRF(1) receptor desensitization were similar. A significant 3-fold increase in GRK3, but not GRK2, mRNA levels accompanied the emergence of CRF(1) receptor desensitization in Y79 cells exposed to CRF. In preliminary experiments, retinoblastoma GRK3 protein expression became upregulated during a 48-h CRF exposure. Neither GRK3 nor GRK2 expression increased in Y79 cells exposed to urocortin for 10 min to 48 h. We hypothesize that GRK3 upregulation may be a cellular negative feedback process directed at maximizing CRF(1) receptor desensitization by heightening GRK3 phosphorylating capacity during prolonged exposure to high CRF. Regulation of GRK expression associated with urocortin- and CRF-induced CRF(1) receptor desensitization appears to differ, despite a similar level of signaling via the cAMP-protein kinase A pathway.

Base Sequence↗
PubMed2002

Distinct signal transduction processes by IL-4 and IL-13 and influences from the Q551R variant of the human IL-4 receptor alpha chain.

BACKGROUND: Although IL-4 and IL-13 share the IL-13 receptor, IL-13 exhibits unique functions. To elicit the cellular basis of these differences, signal transduction processes have been compared. Additionally, the role of the IL-4 receptor alpha (IL-4Ralpha) variant Q551R was investigated. METHODS: Peripheral blood mononuclear cells from donors were stimulated with IL-4 and IL-13. The phosphorylation status of effector substrates was detected by immunostaining. Binding of SHP-2 to IL-4Ralpha was investigated by using synthetic peptides. RESULTS: SHP-2 bound IL-4Ralpha synthetic peptide; this binding was reduced in the presence of the R551 variant. Stimulation with IL-4 increased SHP-1 phosphorylation, however, stimulation with IL-13 increased SHP-2 phosphorylation. PI3-kinase phosphorylation was elevated following stimulation with IL-13 in all individuals and with IL-4 only in R551 individuals. Jak1, Tyk2 and IRS-2 signals were reduced after IL-13 stimulation in Q551 individuals. STAT3 phosphorylation was markedly increased in R551 individuals, following stimulation with both IL-4 and IL-13. However, STAT3 was only detected immediately in nuclear extracts from variant individuals after stimulation with IL-13; in wildtype individuals STAT3 was only detected after IL-4 treatment. CONCLUSION: IL-4 and IL-13 appear to promote distinct signal transduction cascades. SHP-1 seems to be predominately activated by IL-4 and to influence the PI3-kinase, in contrast, SHP-2 seems to be predominately activated by IL-13 and to influence Jak1, Tyk2 and IRS-2. Both phosphatases control STAT3. In the presence of the variant R551, SHP-1/2 activation is reduced and signal transduction is altered. STAT3 signaling appears be further regulated on the level of nuclear translocation.

Arginine↗
PubMed2002

[Surgery for mitral valve insufficiency].

BACKGROUND: Ischemic mitral regurgitation (IMR) is a severe condition which may be best treated by surgery, notwithstanding a relatively high mortality rate. OBJECTIVES: To evaluate the results of mitral valve replacement or repair in patients with IMR. PATIENTS AND METHODS: Retrospective review of the clinical records in 29 patients with IMR who were surgically treated from 1990 to 1999. They represent 8% of surgical procedures on the mitral valve. RESULTS: Mean age was 67 +/- 9 years. Surgery was performed urgently in 19 patients (66.5%). NYHA functional class was 3.4 +/- 0.8. The mechanism of IMR was annular dilatation and spreading of papillary muscles in 18 patients, papillary muscle rupture in 9 and fibrosis in 2. Mitral valve replacement was performed in 14 patients and mitral valve repair in 15. Twenty four patients (83%) had concomitant myocardial revascularization. Overall surgical mortality was 24%; 26% for mitral replacement and 13% for mitral valve repair (p = 0.215). On follow up of 26 +/- 33 months, one year survival was 76 +/- 0.8% and 5 years survival was 59 +/- 12%. Excluding in hospital mortality, survival was 100% at one year and 78 +/- 14% at 5 years. Functional class improved in all survivors, to 1.4 +/- 0.5. Late echocardiographic evaluation of patients with mitral valve repair showed absence of mitral regurgitation in 58%, 1+ MR in 17% and 2+ MR in 25%. CONCLUSION: In spite of a high perioperative mortality, surgery for IMR is a valuable procedure for patients with an otherwise highly lethal disease.

Aged↗
PubMed2002

[A 36 years experience with implantable pacemakers. A historical analysis].

BACKGROUND: The implantation of pacemakers improves cardiac function and quality of life, in particular with dual chamber DDD and DDDR modes. AIM: To evaluate our clinical experience and results on pacemaker implantation, from 1963 to 1998. MATERIAL AND METHODS: Computerized data collected from 2,445 consecutive paced patients was reviewed. A total of 3,554 operative procedures were performed, including 412 procedures for complications and 697 pacemaker replacement. Patient survival was determined from clinical records, inquiry to pacemaker manufacturers and death certificates from Servicio de Registro Civil e Identificación de Chile (Chilean Civil and Identification Registry). RESULTS: Use of dual chamber (DDD and DDDR) pacemakers increased progressively up to 74% from 1988 to 1998. Complication rate was 42% in the 1963-1976 study period, it decreased to 10.6% in the 1977-1987 study period, and to 5.6% by 1988-1998. Only two patients died during surgery in the study period (0.08%). In the 1977-1987 period, pacemakers lasted 10.6 years. Survival rates were 52% at ten years, 33% at 15 years, and 21% at 20 years, with a median survival of 11.7 years, and 7.24 years in patients over 80 years old. CONCLUSIONS: Transvenous permanent pacing can be accomplished today with a low complication rate, mainly due to better technology and surgical procedures.

Aged↗
PubMed2002

Angiotensin I-converting enzyme insertion/deletion polymorphism and adrenergic response to exercise in hypertensive patients.

BACKGROUND: The insertion/deletion ACE polymorphism (ACE I/D) regulates different levels of circulating and tissue ACE activities, which may induce diverse adrenergic responses to physiological stimuli. The aim of this study was to evaluate the influence of the ACE I/D polymorphism on the adrenergic response to isotonic exercise in middle-aged hypertensive patients. MATERIAL/METHODS: Submaximal exercise (on a treadmill, using the Naughton protocol at 75% of maximal heart rate) was performed in 34 patients homozygous for the ACE I/D polymorphism (ACE II and ACE DD) with untreated essential hypertension (II = 19, DD = 15). Plasma venous adrenaline and noradrenaline were measured at rest and at submaximal exercise. RESULTS: Plasma ACE activity was significantly higher in the hypertensive patients carrying the ACE DD genotype compared with the ACE II group. Left atrium size, as well as LV dimensions, mass, and function, were similar in both groups. Total exercise time, baseline and 75% maximal heart rate (MHR) and blood pressure were similar in both groups. Baseline plasma adrenaline and noradrenaline levels were similar in both groups and increased significantly (p<0.05) by ca. 300% at submaximal exercise without differences between groups. CONCLUSIONS: The presence of the D allele on the ACE gene in middle-aged hypertensive patients determines higher circulating ACE activity but not increased sympathetic activity in response to submaximal exercise.

Adult↗
PubMed2002

[Hypercoagulability in atrial fibrillation and its relationship with risk factors for systemic embolism].

BACKGROUND: Atrial fibrillation is associated to a high risk of systemic embolism and to hypercoagulability. AIM: To evaluate the activation of the coagulation cascade through determinations of the thrombin-antithrombin complex in patients with atrial fibrillation and to correlate this data with the clinical and echocardiographic risk factors for systemic embolism. PATIENTS AND METHODS: In 53 patients with atrial fibrillation plasma levels of the thrombin-antithrombin complex were determined on admission to a coronary care unit and 30 days later. Using a univariate and multiple regression analysis, the association basal thrombin-antithrombin with the duration of the arrhythmia, age over 70 years, previous use of antiplatelet agents, history of hypertension, mitral valve disease, diabetes, heart failure, previous systemic embolism, left atrial diameter and the presence of spontaneous contrast echo or thrombus in the left atrial appendage, was studied. RESULTS: Basal thrombin-antithrombin values were 40.1 +/- 69 mg/L (Median 8.34 [3.0-47.5]) compared to 2.7 +/- 3.3 mg/L in healthy controls (p < 0.001). No significant correlation was found between activation of the coagulation cascade and risk factors for systemic embolism. There were no significant differences in thrombin-antithrombin values between patients with chronic or paroxysmal atrial fibrillation (29.5 +/- 43 mg/L and 49.4 +/- 83 mg/L respectively). Mean thrombin-antithrombin values in patients under antiplatelet agents were lower than in those without treatment (17.3 +/- 43 vs 66.8 +/- 127 mg/L; p = 0.018). CONCLUSIONS: The activation of the coagulation cascade in patients with atrial fibrillation was confirmed. However, no association of this activation with well known clinical and echocardiographic risk factors for systemic embolism, was found. Previous antiplatelet treatment prevented a higher activation of the coagulation cascade.

Aged↗