Safety of thrombolytic therapy in patients with prosthetic heart valve thrombosis who have high international normalized ratio levels.

BACKGROUND AND AIM: Prosthetic valve thrombosis (PVT) is a rare but life-threatening complication of heart valve replacement. Based on the current guidelines, the treatment of a large number of these patients could be performed through the administration of thrombolytic agents. In the present study, we aim to assess the safety of thrombolytic therapy in patients with PVT who have high international normalized ratio (INR) levels. METHODS: In this study, we retrospectively analyzed outcomes of thrombolytic therapy in 65 PVT patients with different levels of INR at the time of fibrinolysis at a tertiary cardiac center. RESULTS: Mean age of patients was 51.6 ± 12.47 years. The tricuspid valve was the most common site of prosthetic valve thrombosis (64.6%). The Median (range) of INR was 2.1 (0.9-4.9). The majority of patients (50.8%) achieved a complete response following thrombolytic treatment. There were no cases of intracranial hemorrhage. Other major and minor bleedings occurred in 3 (4.6%) and 10 (15.4%) patients, respectively. No embolic stroke and systemic embolism were observed. We found no significant difference in the frequency of major (P-value = .809) and minor (P-value = .483) bleeding as well as response to thrombolytic therapy (P-value = .658) between patients with different levels of INR. Total administered dose of Streptokinase was also similar in PVT patients with or without major (P-value = .467) and minor (P-value = .221) bleeding complications. CONCLUSIONS: We concluded that there was no significant difference between PVT patients presenting with subtherapeutic and high INR levels who received thrombolytic treatments regarding both minor and major bleeding complications as well as response to thrombolysis.

Taq1B Polymorphism of Cholesteryl Ester Transfer Protein (CETP) and Its Effects on the Serum Lipid Levels in Metabolic Syndrome Patients.

The metabolic syndrome (MetS) is one of the most important risk factors for type 2 diabetes and cardiovascular disease. This syndrome is characterized by abdominal obesity, hypertension, insulin resistance, and dyslipidemia. The plasma origin of Cholesteryl ester transfer protein (CETP) is responsible for transferring cholesterol esters from high-density lipoprotein particles to apolipoprotein B containing lipoproteins compartment. We conducted this study to investigate the association between CETP gene Taq1B (rs708272) polymorphism in the metabolic syndrome among Iranian subjects. A sample size of 200 patients diagnosed with MetS together with 200 healthy donors as control were enrolled in this study. The investigation of polymorphism was performed by the use of polymerase chain reaction and restriction fragment length polymorphism analysis. To determine the relationship between polymorphism and lipid profile, we measured lipids and CETP concentration in metabolic syndrome and control subjects. Genotype distribution and allelic frequencies of polymorphism were determined and compared in both groups. Our findings showed that all clinical and biochemical characteristics in patients differed from the control group. The results showed that genotype and allele frequency of the Taq1B polymorphism was not significantly different between two groups. Instinctively, CETP was significantly higher in metabolic syndrome (1.64 ± 0.32 µg/ml) than in control (1.53 ± 0.34 µg/ml). A low level of CETP was found in blood of B2B2 typified genotype. In spite of Taq1B polymorphism on ester transfer protein concentration, no direct correlation was found between this polymorphism and metabolic syndrome.

Development of novel biocompatible hybrid nanocomposites based on polyurethane-silica prepared by sol gel process.

Due to high biocompatibility, polyurethane has found many applications, particularly in development of biomedical devices. A new nanocomposite based on thermoset polyurethane and silica nanoparticles was synthesized using sol-gel method. Sol-gel process was fulfilled in two acidic and basic conditions by using tetraethylorthosilicate (TEOS) and trimethoxyisocyanatesilane as precursors. The hybrid films characterized for mechanical and surface properties using tensile strength, contact angle, ATR-FTIR and scanning electron microscopy. Biocompatibility and cytotoxicity of the hybrids were assessed using standard MTT, LDH and TUNEL assays. The results revealed that incorporation of silica nanoparticles was significantly improved tensile strength and mechanical properties of the hybrids. Based on the contact angle results, silica nanoparticles increased hydrophilicity of the hybrids. Biocompatibility by using human lung epithelial cell line (MRC-5) demonstrated that the hybrids were significantly less cytotoxic compared to pristine polymer as tested by MTT and LDH assays. TUNEL assay revealed no signs of apoptosis in all tested samples. The results of this study demonstrated that incorporation of silica nanoparticles into polyurethane lead to the enhancement of biocompatibility, indicating that these hybrids could potentially be used in biomedical field in particular as a new coating for medical implants.