Soluble sST2 biomarker analysis for fibrosis development in atrial fibrillation. A case control study.

ABSTRACT: Objectives. Atrial fibrillation (AF) is a clinically relevant supra-ventricular arrhythmia which represents an independent risk factor for development of heart failure and ischemic stroke. The present study aims at the investigation of the possible clinical role of the soluble sST2 biomarker to evaluate the fibrosis in a group of patients with first diagnosed or permanent AF. The possible association with the left atrium size is also studied. Materials and Methods. The serum concentrations of the biomarker have been measured in a group of 58 patients (mean age 83.6 ± 6.0 years) and 40 individuals, assumed healthy and without AF, constituted the control group. The analysis is carried out by means of a high-sensitivity enzyme-linked immunosorbent assay. Results. The mean concentration of sST2 is 26.1 (22.7-30.5) ng/mL in the AF group, while in the control is 17.3 (15.7-18.9) ng/mL. Remarkable differences have been obtained for the two subsets with first diagnosed (23 (21.2-24) ng/mL) and permanent AF (30.5 (28.6-32) ng/mL). The analysis has been completed with a trans thoracic echocardiographic exam to evaluate the left atrium size and the left ventricular ejection fraction. Conclusions. The sST2 serum concentrations are found to be higher in the permanent AF with respect to the cases where the AF is of new onset or follow a paroxysmal pattern. The results support the adoption of the marker to evaluate the degree of fibrosis related to the left atrium of fibrillating patients. A positive association has been proved between the left atrium size and the sST2 concentrations.

The Fluid-Dynamics of Endo Vascular Aneurysm Sealing (EVAS) System failure.

PURPOSE: The main objective of this work is to investigate hemodynamics phenomena occurring in EVAS (Endo Vascular Aneurysm Sealing), to understand if and how they could lead to type 1a endoleaks and following re-intervention. To this aim, methods based on computational fluid mechanics are implemented as a tool for checking the behavior of a specific EVAS configuration, starting from the post-operative conditions. Pressure and velocity fields are detailed and compared, for two configurations of the Nellix, one as attained after correct implantation and the other in pathological conditions, as a consequence of migration or dislocation of endobags. METHODS: The computational fluid dynamics (CFD) approach is used to simulate the behavior of blood within a segment of the aorta, before and after the abdominal bifurcation. The adopted procedure allows reconstructing the detailed vascular geometry from high-resolution computerized tomography (CT scan) and generating the mesh on which the equations of fluid mechanics are discretized and solved, in order to derive pressure and velocity field during heartbeats. RESULTS: The main results are obtained in terms of local velocity fields and wall pressures. Within the endobags, velocities are usually quite regular during the whole cardiac cycle for the post-implanted condition, whereas they are more irregular for the migrated case. The largest differences among the two cases are observed in the shape and location of the recirculation region in the rear part of the aorta and the region between the endobags, with the formation of a gap due to the migration of one or both of the two. In this gap, the pressure fields are highly different among the two conditions, showing pressure peaks and pressure gradients at least four times larger for the migrated case in comparison to the post-implanted condition. CONCLUSIONS: In this paper, the migration of one or both endobags is supposed to be related to the existing differential pressures acting in the gap formed between the two, which could go on pushing the two branches one away from the other, thus causing aneurysm re-activation and endoleaks. Regions of flow recirculation and low-pressure drops are revealed only in case of endobag migration and in presence of an aneurysm. These regions are supposed to lead to possible plaque formation and atherosclerosis.

Are blood and valve cultures predictive for long-term outcome following surgery for infective endocarditis?

OBJECTIVE: To evaluate whether perioperative bacteria identification in blood and/or in valve cultures can predict early and late outcome of surgery for infective endocarditis, a retrospective study was performed. METHODS: Between January 1978 and December 1998, 232 patients, 79 (34.1%) female and 153 (65.9%) male with mean age of 44. 95+/-1.03 years (range 8-79) underwent surgery for infective endocarditis on a native (162 cases) or prosthetic (70 cases) valve. Patients were divided into three groups according to the perioperative x of microbiological tests: Group A: patients with preoperative positive blood cultures (83 cases); Group B: patients with positive valve cultures (35 cases); Group C: patients with negative blood and valve cultures (114 cases). Categorical values were compared by chi(2) analysis, whereas continuous data were compared by ANOVA and Bonferroni correction for post hoc comparisons. Analysis of late survival and complications was performed with Kaplan-Meier and Log Rank test. Late mortality, reoperation, perivalvular leak, recurrence of infection were considered as treatment failure. All data were presented as mean+/-standard error. RESULTS: Hospital mortality was 10.8% (9/83) in Group A, 8.6% (3/35) in Group B, and 14.9% (17/114) in Group C (P=0.52; not significant (NS)). Ten-year survival was 62.7+/-8% in Group A, 43.9+/-19% in Group B and 62.7+/-7% in Group C (P=0.38; NS). Ten-year freedom from reoperation was 85.2+/-6% in Group A, 37.9+/-20% in Group B and 80+/-6% in Group C (P=0.0034). Ten-year freedom from treatment failure was 56.3+/-8% in Group A, 31.6+/-16% in Group B and 55. 3+/-7% in Group C (P=0.46; NS). CONCLUSIONS: Positive blood and tissue cultures are not predictive for hospital mortality and late treatment failure in patients with infective endocarditis. Positive valve cultures, a common finding in patients with staphylococcal endocarditis, are predictive for a higher risk of reoperation.

Ventricular tachyarrhythmias following coronary surgery: predisposing factors.

The perioperative factors potentially associated with post-coronary artery bypass grafting (CABG) ventricular tachyarrhythmias (VT) onset have not been deeply investigated. Monomorphic or polymorphic ventricular tachycardia and ventricular fibrillation represent the most dreadful arrhythmic events that can complicate the postoperative course of CABG. As a consequence, the aim of our paper was to identify which perioperative variables might predict post-CABG VT occurrence. One hundred and fifty-two consecutive patients who underwent CABG surgery at our Institution were included in the study. Post-CABG VT occurred in 13 out of 152 patients (8.5%, six cases of monomorphic ventricular tachycardia and seven cases of ventricular fibrillation). At univariate analysis, VT patients were significantly younger (54.8+/-6.6 vs. 60.1+/-8.8, P=0.038), exhibited a more severe coronary artery disease (CAD) (number of diseased vessels 2.92+/-0.3 vs. 2.45+/-0.7, P=0.023, and percentage of patients with three-vessel CAD 91.7% vs. 57.3%, P=0.043) and received a greater number of CABGs than those remaining in sinus rhythm (SR) (percentage of patients receiving three or more CABGs 76. 9% vs. 38.8%, P1000 76.9% vs. 38%, Pnormal range 72.7% vs. 30.7%, P=0.014), electrolyte derangement (84.6% vs. 45.6%, P=0.017) and a severe haemodynamic impairment (need for IABP 23% vs. 2.9%, P1000, postoperative electrolyte imbalance, the need for three or more CABGs and of IABP all were independent correlates for VT. In conclusion, post-CABG VT seem to be related to the preexistence of a severe underlying coronary artery disease along with perioperative triggering factors such as acute ischemia, electrolytic disorders and a sudden haemodynamic impairment.

Treatment of recurrent postoperative mediastinitis with granulated sugar.

BACKGROUND: The authors report their experience with granulated sugar as dressing technique in the treatment of postoperative mediastinitis refractory to a closed irrigation system. METHODS: Between January 1990 and January 1998, mediastinitis developed in 61 (0,93%) of 6521 patients who had undergone open heart surgery. Diagnosis of sternal infections was based on wound tenderness, drainage, cellulitis, fever associated with sternal instability. All of them were initially treated with surgical debridement and closed chest irrigation. Nine patients with postcardiotomy mediastinitis refractory to closed chest irrigation underwent open dressing with granulated sugar. All of them were febrile with leukocytosis and positive wound cultures. RESULTS: Bacteria isolated were staphylococcus aureus in 6 cases, staphylococcus epidermidis in 2 and pseudomonas in 1. Redebridement was performed in all cases and the wound was filled with granulated sugar four times a day. Fever ceased within 4.3+/-1.3 days from the beginning of treatment and WBC became normal after 6.6+/-1.6 days. Three patients had hyperbaric therapy as associated treatment. Complete wound healing was achieved in 58.8+/-32.9 days (three patients underwent successful pectoralis muscle flaps). CONCLUSIONS: Sugar treatment is a reasonable and effective option in patients with mediastinitis refractory to closed irrigation treatment. It may be used either as primary treatment or as a bridge to pectoralis muscle flaps.

Determinants and prognostic value of ischemic necrosis in early biopsies following heart transplant.

To evaluate the impact of early ischemic necrosis (IN) on the early and late outcome of heart transplantation, we reviewed our 11-year experience. Between January 1988 and June 1999, 207 heart transplants were performed in 205 patients (174 male and 31 female). Criteria for donor and recipient selection, and protocols for postoperative immunosuppression and rejection monitoring have remained unchanged over this period. Three different cardioplegic solutions were employed in graft preservation: St. Thomas Hospital solution in the earliest 31 cases (15%), University of Wisconsin solution in 96 cases (46.4%), and Celsior solution in the last 80 cases (38.6%). All patients who underwent at least one endomyocardial biopsy (176 patients) were divided into two groups according to the findings of IN within the early 3 postoperative months (group A, 49 patients with IN; group B, 127 patients without IN). The following variables were estimated in each group: donor and recipient age, ischemic time, type of cardioplegia, late mortality for cardiac causes, incidence of grade >2 rejection within the first 6 postoperative months, late incidence of grade >2 rejection, late incidence of NYHA class >II. No significant difference was found in any parameter between the two groups, except for the type of cardioplegic solution. A significantly higher incidence of ischemic necrosis in hearts preserved with St. Thomas solution was found (P < 0.001). Although pathology findings show that extracellular solutions carried a higher risk of early IN, no associated significant impairment in terms of late survival and event-free rate was observed in recipients with early IN.

Perioperative correlates of malignant ventricular tachyarrhythmias complicating coronary surgery.

Sustained ventricular tachyarrhythmias (VT), such as monomorphic or polymorphic ventricular tachycardia, and ventricular fibrillation, represent the most serious arrhythmic events that can complicate the postoperative course of coronary artery bypass grafting (CABG). The perioperative factors potentially associated with post-CABG sustained VT onset have not been thoroughly investigated. As a consequence, the aim of our study was to identify which perioperative variables might predict post-CABG VT occurrence. One hundred and fifty-two consecutive patients who underwent CABG surgery at our Institute were included in the study. Post-CABG VT occurred in 13 out of 152 patients (8.5%, six cases of monomorphic ventricular tachycardia and seven cases of ventricular fibrillation). Univariate analysis revealed that VT patients were significantly younger (54.8 +/- 6.6 vs 60.1 +/- 8.8, P = 0.038), exhibited more severe coronary artery disease (CAD) (no. of diseased vessels, 2.92 +/- 0.3 vs 2.45 +/- 0.7, P = 0.023; and percentage of patients with three-vessel CAD, 91.7 vs 57.3%, P = 0.043), and received a greater number of CABGs than those remaining in sinus rhythm (SR) (percentage of patients receiving three or more CABGs, 76.9 vs 38.8%, P = 0.018) Moreover, VT patients more frequently developed intra- or postoperative myocardial infarction (total CK > 1,000, 76.9 vs 38%, P = 0.016; and MB-CK > normal range, 72.7 vs 30.7%, P = 0.014), electrolyte derangement (84.6 vs 45.6%, P = 0.017), and a severe hemodynamic impairment (need for intra-aortic balloon pump (IABP), 23 vs 2.9%, P = 0.009). On multivariate analysis, total CK > 1,000, postoperative electrolyte imbalance, the need for three or more CABGs, and for IABP all were independent correlates for VT. In conclusion, post-CABG VT seem to be related to the preexistence of a severe underlying coronary artery disease along with perioperative triggering factors, such as acute ischemia, electrolytic disorders, and sudden hemodynamic impairment.