P752 Mitral regurgitation in patients with severe aortic stenosis: role of valvular calcification in the persistence of mitral regurgitation after aortic valve replacement

Introduction

mitral regurgitation is often associated with severe aortic stenosis but the indications for its correction at the time of aortic valve surgery are still unclear. Despite the indication for mitral valve repair or replacement in the case of severe secondary mitral regurgitation, many patients are left untreated. This is due to the common belief that secondary mitral regurgitation mostly improves after the aortic valve is treated.

Purpose

the aim of the study is to investigate the prevalence and distribution of mitral calcifications, their role in the development of mitral regurgitation and in its reduction after aortic valve replacement.

Methods

we reviewed all patient’s records who underwent aortic valve replacement for aortic stenosis at our institution from 12/2014 to 12/2016. Pre and post-operative echocardiograms were reviewed by experienced echocardiographer. Patients were then divided into 4 categories (functional, mild, moderate and severe calcification) on the basis of the presence, distribuition and severity of calcification on the mitral apparatus.

Results

at the end 651 patients were collected and analyzed. Mean age was 74yo. 334 (51,4%) of them were males. Most patients (63,1%) had only mild mitral regurgitation but 147 (22,6%) of them had moderate or severe mitral regurgitation. The presences of moderate or severe calcification of the mitral apparatus resulted to be a risk factor for the presence of mitral regurgitation associated with aortic stenosis as shown in Table 1. After surgical aortic valve replacement less than 21% of the patients showed a reduction of the degree of mitral regurgitation. We found no statistical difference between groups about mitral regurgitation changes after aortic valve replacement.

Conclusions

Mitral regurgitation is a common finding in patients with severe aortic stenosis and it’s prevalence is higher in patients with mitral calcifications. Few patients, however showed a reduction in the degree of mitral regurgitation after surgical aortic valve replacement with no difference related to the severity of annular or leaflets calcifications.

TABLE 1 Logistic regression for the presence of mitral regurgitation Mitral Regurgitation Change after Aortic Valve Replacement CALCIFICATION DEGREE OR C.I. 95% p Reduced p Unchanged p Increased p Functional 53(21%) 176(71%) 18(7%) Mild 1.244571 0.81 - 1.93 0.32 28(20%) 0.86 105(76%) 0.43 6(4%) 0.34 Moderate 1.637297 1.05 - 2.56 0.03* 25(17%) 0.41 109(76%) 0.34 9(6%) 0.86 Severe 2.369245 1.46 - 3.85 <0.01* 29(25%) 0.48 78(68%) 0.67 7(6%) 0.86 OR= Odds Ratio; C.I.=Confidence Interval; Functional= no calcification; Mild, Moderate and Severe= degree of mitral annular and leaflets calcifications.

High sensitivity measurement system for the direct-current, capacitance-voltage, and gate-drain low frequency noise characterization of field effect transistors

Measurements of current fluctuations originating in electron devices have been largely used to understand the electrical properties of materials and ultimate device performances. In this work, we propose a high-sensitivity measurement setup topology suitable for the automatic and programmable Direct-Current (DC), Capacitance-Voltage (CV), and gate-drain low frequency noise characterization of field effect transistors at wafer level. Automatic and programmable operation is particularly useful when the device characteristics relax or degrade with time due to optical, bias, or temperature stress. The noise sensitivity of the proposed topology is in the order of fA/Hz(1/2), while DC performances are limited only by the source and measurement units used to bias the device under test. DC, CV, and NOISE measurements, down to 1 pA of DC gate and drain bias currents, in organic thin film transistors are reported to demonstrate system operation and performances.

Intra-uterine parvovirus B19 infection and meconium peritonitis

B19 fetal infection has been associated with hydrops or fetal death. We report four cases of meconium peritonitis in hydropic fetuses with laboratory diagnosis of B19 infection. Parvovirus B19 DNA was detected by in situ hybridization both in cord blood and in amniotic cells in three fetuses, while in one case only cord blood was available and proved positive. Signs of active or recent B19 infection in maternal serum samples were documented only in two cases, which proved positive for specific IgM antibodies anti-B19. Maternal B19 infections were asymptomatic and fetal anomalies were observed during a routine ultrasound scan. A common feature of the hydropic fetuses was the presence of abdominal ascites concomitant with or preceding alterations, suggesting meconium peritonitis. The four pregnancies had a preterm outcome: in two cases infants recovered following surgical treatment, in one case spontaneously, and the other one was stillborn. Since vascular inflammation has been documented in B19 infection and congenital bowel obstruction results from vascular damage during fetal life, our observation suggests the need for investigating B19 infection in the presence of meconium peritonitis for a better understanding of the pathogenetic potential of B19 parvovirus in intra-uterine infection.