Fractional flow reserve assessment to determine the indications for myocardial revascularisation in patients with borderline stenosis of the left main coronary artery

INTRODUCTION: Reliable assessment of clinical significance of borderline angiographic lesions found within the left main coronary artery (LM) is often impossible. Measurement of fractional flow reserve (FFR) is commonly used to verify borderline stenoses of the coronary arteries. However, the usefulness of FFR measurements has been validated only for arteries other than the LM. AIM: Evaluation of the measured FFR value in determination of the indications for myocardial revascularisation in borderline LM stenosis. METHODS: The study involved 38 patients aged 55+/-9 years (range 41-74 years) with isolated borderline LM stenosis. Each patient had the measurement of FFR performed during intravenous adenosine infusion at a dose of 140 microg/kg/min. Patients were referred for revascularisation if FFR was <0.75. RESULTS: The mean LM stenosis in quantitative coronary angiography (QCA) was 45+/-10%. FFR<0.75 was found in 18 (47%) patients, whereas 20 (53%) subjects had FFR < or =0.75. In subjects with FFR <0.75 QCA showed significantly lower minimal lumen diameters (MLD) at the site of stenosis (1.84+/-0.45 vs 2.24+/-0.49, p=0.014). Additionally, a significant correlation was found between FFR and MLD (r=0.59, p<0.001). The mean clinical follow-up was 2 years (range 1-3 years). There were two (11%) fatal events in patients with FFR < or =0.75 who underwent CABG. One (5%) patient with FFR >0.75 underwent elective CABG due to progression of LMN stenosis. Moreover, one (5%) patient experienced myocardial infarction not related to borderline stenosis of the LM. CONCLUSIONS: The measurement of FFR confirms the clinical significance of stenosis only in half of the patients with borderline isolated lesion of the left main coronary artery. Withdrawal from intervention in patients with FFR > or =0.75 is safe and is associated with favourable clinical outcomes in two-year follow-up.     

Intravascular ultrasound-guided high-pressure balloon predilatation for optimal drug-eluting stent deployment in restenosis of a stent implanted 7 years earlier. Do we know the right technique for in-stent restenosis restenting?

Although off-label, drug-eluting stent (DES) implantation is a preferred intervention for in-bare metal stent restenosis (BMS ISR). Off-label DES implantation appears to be associated with a higher risk of stent thrombosis and lesion recurrence. Accordingly, routine BMS ISR restenting with DES is associated with more frequent subsequent thrombosis. Intravascular ultrasound (IVUS) studies point to stent underexpansion as the major mechanism of late DES failure. We report a case of a patient with BMS ISR in whom IVUS clarified initial BMS expansion; consequently, high-pressure predilatation with an angiographically oversized conventional balloon was applied prior to DES deployment; and finally, IVUS verified the stent expansion.     

Association between the Pl(A) platelet glycoprotein GPIIIa polymorphism and extent of coronary artery disease

BACKGROUND: The Pl(A2) allele of the gene encoding for GPIIIa subunit of the platelet membrane receptor glycoprotein (GP) IIb/IIIa has been suggested as a significant risk factor for thrombotic complications of coronary artery disease (CAD). The aim of the current investigation was to investigate the association between Pl(A) GPIIIa polymorphism and the extent of angiographically confirmed CAD in patients from the north region of Poland. METHODS: The study was performed in 397 male Caucasian patients. All subjects had significant coronary artery stenosis confirmed by elective coronary angiography. Screening for the Pl(A) GPIIIa genotypes was performed by polymerase chain reaction of genomic DNA, followed by NciI digestion and agarose gel electrophoresis. RESULTS: The genotype distribution of the Pl(A) GPIIIa polymorphism in our study group was Pl(A1/A1)-75%, Pl(A1/A2)-24% and Pl(A2/A2)-1% with Pl(A1) and Pl(A2) allele frequencies of 0.87 and 0.13, respectively. The prevalence of the homozygous Pl(A1/A1) genotype among subjects with multiple-vessel CAD (two or three vessels with at least 50% stenosis) was significantly higher than in patients with single-vessel disease; the odds ratio of Pl(A2/A2) or Pl(A1/A2) patients for having multiple-vessel CAD was 0.46 (95% CI 0.27-0.77, P<0.01). The mean CAD score for Pl(A1/A1) patients was significantly higher in comparison to Pl(A2/A2) and Pl(A1/A2) patients (7.58+/-2.20 and 6.98+/-2.37, respectively, P<0.05). CONCLUSIONS: Our results suggest, that the Pl(A1/A1) genotype of Pl(A) GPIIIa polymorphism is associated with more severe CAD in male Caucasian patients from the north region of Poland.     

Pathological changes of liver in infection of Fasciola hepatica

Pathological changes of liver in infection of Fasciola hepatica. Fasciolosis caused by Fasciola hepatica is a hepatic parasitic infection that affects numerous mammal species, mainly ruminants, in several countries of Europe, Asia and America. The economic significance of fasciolosis is mainly due to direct losses caused by a decrease of weight rate, milking capacity and the confiscation of altered livers in slaughterhouse. In this review we present mechanisms of damaging of host liver during invasion of Fasciola hepatica. Parasites digest hepatic tissue and cause extensive parenchymal destruction with intensive haemorrhagic lesions and immunological reactions. Mechanical liver damage is due to migrating juvenile fluke. Macerated hepatic cells have been observed inside the oral sucker and pharynx. Moreover, the process of ulceration of liver tissue was observed in regions adjacent to the spiny body of fluke tegument. On the other hand, the injury of the liver can be induced chemically by factors produced or induced by the fluke. Probably, fluke proteases and other tissue-degrading enzymes can be responsible for negative effect on liver parenchyma. There is no evidence to link fluke-enzymes with tissue penetration. The consequences of liver damage resulting from the migrating flukes compromises liver function which is reflected in changes of plasma protein concentration (albumin, globulin). Additianally, changes of levels of hepatic enzymes released into the blood as a result of damage of liver tissue are used to monitor the progress of the infection in a variety of Fasciola hepatica hosts and as a sensitive diagnostic aid in field infection.     

Surface Evaluation of Orthodontic Wires Using Texture and Fractal Dimension Analysis

Mechanical properties of orthodontic wires can have a very significant impact both on the resistance of the entire appliance to the oral cavity conditions and directly on the effectiveness of the therapy. Striving to achieve repeatability of mechanical characteristics of orthodontic wires of a given type should be an obligatory condition in their production. To achieve it, these components should be thoroughly analyzed using various mechanical tests. Twenty-four steel and nickel-titanium orthodontic wires from four different manufacturers were examined. Each wire was subjected to fractal dimension analysis and texture analysis. The two sides of each wire were compared against each other, as well as in terms of variation in the surface area for each wire type made by different manufacturers. Most wires showed significant variation in fractal dimension and texture, both when comparing two sides of the same wire and between individual wires of a given type made by a single manufacturer. When conducting research and clinically using orthodontic wires made of Ni-Ti alloys and stainless steel, it should be assumed that the surface of orthodontic wires shows a significant degree of variation, and wires of the same type from the same manufacturer may differ significantly in this respect.     

Vascular complications after transcatheter aortic valve implantation (TAVI): risk and long-term results

Vascular complications are the main safety limitations of transcatheter aortic valve implantation (TAVI). The aim of the study was to assess the incidents, predictors, and the impact of early vascular complications on prognosis after TAVI. This was a single-center analysis of vascular complications related to TAVI. Early vascular complications were defined as incidents within 30 days after TAVI and comprised complications related to transvascular: transfemoral/transsubclavian ,and transapical bioprosthesis implantation. Evaluated risk factors were: (1) clinical characteristics, (2) TAVI route, and (3) center experience. In patients with transvascular TAVI the impact of: (1) diameters of access arteries, vascular sheathes and difference between them, (2) arterial wall calcification, and (3) ProStar devices used for access site closure were assessed. Arterial wall calcification and arteries diameters were measured by 64-slice computer tomography. Arterial wall calcification was graded according to 5° scale. Results: between 2009–2011; follow-up 1–23 months (12 ± 15.55), 83 consecutive patients, and 62–91 (81.10 ± 7.20) years, underwent TAVI: 67 (80.72 %) patients had transvascular, and 16 (19.27 %) patients had transapical bioprosthesis implantation. We noted 44 (53.01 %) early vascular complications: 17 (20.48 %) were major and 27 (32.53 %) were minor incidents. Independent predictors of early vascular complications were: history of anaemia (OR 3.497: 95 % CI [1.276–9.581]; p = 0.014), diabetes (OR 0.323: 95 % CI [0.108–0.962]; p = 0.042), percutaneous coronary intervention performed as preparation for TAVI (OR 4.809: 95 % CI [1.172–19.736]; p = 0.029), and arterial wall calcification (OR 1.945: 95 % CI [1.063–3.558]; p = 0.03). Of 6 (7.22 %) in-hospital and 10 (12.98 %) late deaths: 5 (83.33 %) patients and 8 (80 %) patients respectively had post-procedural vascular complications. Vascular complications, which occurred in 30-days after TAVI, predict late mortality (p = 0.036). Conclusions derived were: (1) TAVI patients with history of anaemia and diabetes required careful monitoring for early vascular complications. (2) If coronary intervention before TAVI is required, it should be performed in the time allowing vascular injuries to heal. (3) Calcification of access arteries is an independent predictor of post-procedural vascular complications; therefore, its estimation should be a regular element of preceding computer tomography. (4) Vascular complications seem to be predictors of late mortality after TAVI.