Multiparametric assessment of the intraprocedural result after transcatheter mitral valve edge-to-edge repair proceduret

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): Research grant

OnBehalf

n/a

Background. Quantification of residual mitral regurgitation (MR) after transcatheter edge-to-edge mitral valve repair (TMVr) is challenging.

Objectives.  To evaluate the feasibility and the performance of an intraprocedural multiparametric approach based on echocardiographic and invasive hemodynamic parameters and to develop a multiparametric scoring system for MR grading after TMVr, and to compare this approach against currently recommended methods. 

Methods. Ninety-three consecutive patients treated with MitraClip (April 2019-July 2020) were enrolled. The protocol of MR evaluation included: 2D and 3D color-Doppler (3D-vena contracta area- 3D-VCA), pulsed-wave Doppler (pulmonary vein- PV flow, stroke volume), continuous-wave Doppler (jet density), morphological parameters (spontaneous echocontrast) and invasive hemodynamic (mean left atrial pressure-LAP, V-wave) at baseline and after clip implantation. A multiparametric score (M-score) was calculated by including the significant predictors (3D-VCA, dense jet on CWD, final LAP, final V wave) of primary endpoint (CV death or HF related hospitalization) at one year follow-up, weighted according to the corresponding odds ratio, to predict the clinical outcome at one-month and one-year follow-up. 

Results. The final study population included 86 pts (mean age 78.3 +8.9yrs, 54.6% primary MR). Procedural success was achieved in 78 pts (90.7%). 3D-VCA (AUC 0.808) and current method for MR grading (AUC 0.801) were comparable predictors of lack of symptom improvement (<5 point change in KCCQ-OS score) at one-month (p = 0.398, DeLong’s test). The M-score performed similarly as predictor of one-month follow-up but was a better predictor of primary endpoint at 1-year (AUC 0.919) compared to single parameters (p = 0.005 vs 3D-VCA DeLong"s test) and currently recommended methods for MR grading (p = 0.006 DeLong"s test). The optimal cut-off was 2 points with 86.7% sensitivity and 83.1% specificity.

Conclusion. We evaluated intraprocedural TMVr result in a multiparametric approach showing that 3D-VCA alone is comparable to current recommended method for MR grading. However, the integration of echocardiographic and invasive hemodynamic parameters into a multiparametric score provided a further added value for predicting clinical outcome  at one-year compared to currently recommended methods for MR grading and to 3D-VCA.

Subacute postoperative atrial fibrillation after heart surgery: incidence and predictive factors in cardiac rehabilitation

Funding Acknowledgements

Type of funding sources: None.

Background. Postoperative atrial fibrillation (POAF) is the most common arrhythmic complication following cardiac surgery. It may occur between the second and fourth postoperative days as acute POAF, or within 30 days as subacute POAF (sPOAF). The incidence varies from 15% to 60%, with the highest rates observed in patients undergoing valvular surgery. POAF is associated with longer hospital stay and higher thromboembolic risk, which consistently increase patients’ morbidity and mortality. Identification of high-risk categories may allow optimization of in-hospital prevention and treatment, possibly improving clinical outcomes.

Aim of the study. The aim of this study was to assess the incidence of sPOAF and to identify possible predictors in patients performing Cardiovascular Rehabilitation (CR) after Cardiac Surgery (CS).

Methods. A single-centre retrospective study was performed on 383 post-cardiac surgery patients hospitalised in our CR Unit for inpatient rehabilitation. The entire population was on sinus rhythm at the admission in CR and continuous monitoring with 12-lead ECG telemetry was performed during the hospital stay. We calculated the incidence of sPOAF and then evaluated the predictive value of the following variables: anamnestic data, type of cardiac intervention, clinical course in both CS and CR Unit, laboratory parameters including baseline neutrophil-to-lymphocyte ratio (NLR).

Results. Median age was 65 years (63% male). sPOAF was documented in 122 cases (31.9%). Patients developing sPOAF were older [median age 69 (63-76) vs. 61 (51-70); p < 0.001)], more frequently underwent complex surgical procedures (50% vs. 36%; p = 0.009) and were known for previous episodes of atrial fibrillation (27.9% vs. 11.2%; p < 0.001). On the first day after surgery (T1), sPOAF group showed higher values of glycemia [median 155 (126.5–186.8) vs. 129 (106.5–164); p < 0.001] and troponin T [median 721.5 (470.1–1084.3) vs. 488 (301.6-776.2); p < 0.001]. The multivariate analysis identified advanced age (OR 1.04, 95% CI 1.01-1.08; p = 0.023), acute POAF in the Cardiac Surgery Unit (OR 3.51, 95% CI 1.62-7.59; p = 0.001), baseline NLR (OR 1.46, 95% CI 1.10-1.93; p = 0.008) and T1-troponin > 552 ng/L (OR 4.16 95% CI 1.50-11.53; p = 0.006) as independent risk predictors of sPOAF during the CR period.

Conclusions. sPOAF is common after cardiac surgery occurring in 31.9% of patients during CR. Age, acute POAF, baseline NLR and elevated troponin T on the first postoperative day were shown predictors of increased sPOAF risk. Recognition of new predictors of POAF could be helpful to better stratify patients, improving management strategies and outcomes.

Cardiovascular rehabilitation after valvular heart surgery: predictive factors of major complications

Background

The population of patients affected by valvular heart disease is growing and for many of them valvular surgery is still considered the gold standard treatment. Cardiovascular Rehabilitation (CR) following intervention is fundamental for the post-surgical functional recovery and for the monitoring and management of complications that may occur after surgery.

Aim of the study

We aimed at identifying predictors of major complications in patients who underwent valvular surgery and subsequently were involved in an in-patient CR program. Major complications were defined as those requiring an in-patient management: severe anemia needing transfusions, infection of the sternal surgical wound requiring an antibiotic treatment, a positive hemoculture in the presence of systemic signs of infection and pericardial effusion requiring surgical drainage.

Methods and statistical analysis

1600 patients who have been hospitalized in our CR Unit after valvular surgery were enrolled (median age 64 years; 60% males). We examined the demographic data, the cardiovascular risk factors, the main comorbidities, the type of heart surgery (type of valvular surgery and the presence of concomitant other cardiac intervention), the complications developed in Cardiac Surgery Unit and in the CR Unit, the in-hospital length of stay, the 6 minutes-walking tests and principal blood tests.

Results

At multivariate analysis we found that chronic renal dysfunction [OR 1,902 (CI 1,103–3,280), p=0,021], complex cardiac intervention [OR 1,554 (CI 1,030–2,344), p=0,036], sternal re-synthesis [OR 4,671 (CI 1,659–13,152), p=0,004], early post-surgical transfusions [OR 1,670 (CI 1,083–2,573), p=0,020] are independent risk factors for major complications, while a higher hemoglobin value at CR admission [OR 0,677 (CI 0,566–0,810), p<0,001] resulted an independent protective factor.

Conclusions

We identified predictors of major complications during CR after valvular surgery. These factors may help in defining the patients at major risk tailoring the patient management, adopting an individualized clinical and instrumental monitoring. A tailored CR period gives the possibility to optimize the use of hospital economic resources and to achieve a better final outcome.

Funding Acknowledgement

Type of funding source: None

P271 Hypoplastic posterior mitral leaflet associated with Marfan syndrome

Picture legend

(A) Mid-esophageal 4-chamber view shows severe hypoplasia of PML (red arrow) and the posterior ventricular myocardial shelf (green arrow). (B) Mid-esophageal commissural view shows a large central MR jet. (C) 3D ventricular perspective of the mitral valve: an almost complete absence of the PML can be appreciated in the central and lateral scallops (grey arrows). (D) CT 3 chamber view shows the myocardial shelf which takes the role of the posterior mitral annulus (blue arrow) and direct PML chordal insertion into the ventricular wall (yellow arrow). (E) CT reconstruction of the mitral valve shows a virtually absent P1 (< 1mm), a P2 length of 4.1 mm, and a P3 length of 5 mm.

Abstract P271 Figure. Hypoplastic posterior mitral leaflet

1183 Three-dimensional echocardiographic paramenters for mitral valve quantification: a feasibility and validation study

Introduction

Mitral regurgitation (MR) severity affects prognosis and a correct quantification is key for surgical indication. A multiparametric approach (MPA) is recommended, as singular parameters suffer pitfalls. Recently suggested three-dimensional echocardiographic (3DE) parameters lack clear reference values. No studies have assessed the feasibility of regurgitant volume (RV) and fraction (RF) using the 3D planimetric area of the mitral annulus (MAA) and of the left ventricular outflow tract (LVOTA).

Purpose

To assess the feasibility and reliability of 3DE, RV and RF obtained by doppler volumetric method using MAA and LVOTA, compare results with 2DE and 3D vena contracta area (VCA) and propose cut-offs for these parameters using MPA as gold standard.

Methods

Patients referred to our Department for MR assessment were enrolled from September 2018 to February 2019 without more than mild aortic regurgitation or severe stenosis, mitral stenosis and previous valvular surgery. Transthoracic 2DE was used to calculate a multiparametric index of MR severity including: jet area/left atrium (LA) area, CW characteristics, 2D vena contracta, PISA, pulmonary vein flow, LA volume and systolic pulmonary artery pressure. Transoesophageal 3DE was used to assess MAA and LVOTA from a 3D dataset. RV and RF were calculated by Doppler volumetric method using the planimetric areas instead of diameters. VCA 3D was calculated from a 3D color dataset as the cross-sectional area of the regurgitant jet. We compared the results between 2DE and 3DE and between functional and organic MR. ROC curves were analyzed to assess diagnostic performance and identify cut-offs for severity prediction. Intraclass correlation coefficient was calculated to assess variability in measurements.

Results

Population was composed by 87 patients (56 male, 65 ± 13 years), 72% organic MR. MAA was larger in 2DE (10.4 ± 3.2 vs 9.8 ± 2.9 cm2,) as was the RV (76.6 ± 36.1 vs 66.4 ± 31.9 ml) and RF (55.4 ± 12.4 vs 50.4 vs 10.9%, all p < 0.0001), while LVOTA was smaller (3.9 ± 0.98 vs 4.1 ± 1.0 cm2, p < 0.0001). RV 2D and RF 2D were larger in the organic MR group (p < 0.0001), meanwhile VCA 3D, RV 3D and RF 3D did not show a significant difference (all p > 0.1). VCA 3D had a good correlation with RV 3D (r = 0.593, p < 0.0001) and RF 3D (r = 0.576, p < 0.0001).

We proposed a cut-off value of 41.5 mm2 for VCA 3D (94% sens, 96% spec, AUC 0.978), 52 ml for RV 3D (84% sens, 78% spec, AUC 0.901) and 47.6% for RF 3D (91% sens, 90% spec, AUC 0.966) to predict MR severity as assessed by MPA.

Intraclass correlation coefficient was 0.980 for MAA and 0.985 for LVOTA for intra-observer variability, while for inter-observer variability it was 0.951 for MAA and 0.962 for LVOTA.

Conclusion

2DE overestimates MA dimensions and underestimates LVOT dimensions thus overestimating RV and RF. 3DE measures are relatively simple and reproducible. Proposed cut-offs for RV, RF and VCA 3D have a good diagnostic power.

428 Prognostic implications of the relationship between effective regurgitant orifice area and left ventricle end diastolic volume in patients with functional mitral regurgitation treated with MitraClip

Funding Acknowledgements

none

Background

The distinction between proportionate and disproportionate functional mitral regurgitation (FMR), based on the relationship between effective regurgitant orifice area (EROA) and left ventricle end diastolic volume (LVEDV), has recently been proposed as a possible new clinical and physiopathological framework to identify patients that could likely benefit from transcatheter mitral repair.

Purpose The aim of our study was to explore the possible prognostic implications of the EROA/LVEDV ratio in patients with FMR treated with MitraClip.

Methods – Baseline EROA/LVEDV was calculated in 137 patients with at least moderate-to-severe, symptomatic FMR treated with MitraClip. All patients underwent clinical, biochemichal and echocardiographic evaluation before MitraClip. EROA was calculated using PISA method. The primary outcome was a composite end-point of all-cause death or re-hospitalization for heart failure (HF).

Results – The median follow-up was 1.1 years. The primary outcome occurred in 59 patients (43 %). Population study showed a LVEDVi 113.52± 32.16 mL/m2, LVEF 29.75± 10.06% and EROA 39.45± 15.43 mm2.. The cut-off value of EROA/LVEDV ratio for primary outcome, identified by receiver operating characteristic curve, was 0.15 (AUC 0,65, p = 0.002) with a sensitivity and specificity of 78% and 52%, respectively. Patients were divided in two groups according to the identified cut-off. Patients with higher ratio (Group I, n = 88) presented a less dilated LV (LVEDVi: 105.1 ± 29.6 mL/m2 vs 128.2 ± 31.9 mL/m2, p < 0.001; LVESVi: 73.1 ± 27.7 mL/m2 vs 94.9 ± 29.05 mL/m2, p < 0.001), and a more severe MR (EROA: 47.9 ± 12.1 mm2 vs 25.1 ± 8.3 mm2, p < 0.001; vena contracta: 7.2 ± 1.3 mm vs 6.5 ± 1.3 mm, p = 0.008). There were no significant differences of left ventricle ejection fraction, right ventricle systolic function and systolic pulmonary pressure between the groups. At univariate analysis, EROA/LVEDV ratio >0.15 (HR = 2.223, 95% CI 1.121-4.411, p = 0.022), baseline evidence of atrial fibrillation (HR = 1.949, 95% CI 1.156-3.283, p = 0.012) and baseline pro-BNP (HR= 1.000, 95% CI 1.000-1.000, p = 0,001) were associated with a worse clinical outcome. At multivariate Cox-regression analysis, both EROA/LVEDV ratio >0.15 and baseline pro-BNP values were identified as independent predictors (HR 2.941, 95% CI 1.035-8.353, p = 0.043; HR = 1.000, 95% CI 1.000-1.000, p = 0.002, respectively). At Kaplan-Meier survival analysis, patients with EROA/LVEDV >0.15 had a significant lower freedom from composite endpoint (log-rank χ2 =5.517, p= 0.019; Fig. 1).

Conclusion

Our data show that EROA/LVEDV ratio was an independent predictor of adverse clinical outcome in FMR patients treated with MitraClip. This preliminary experience shows that this index could help to identify subgroups of patients with potential different clinical benefits from Mitraclip therapy. However, further and extended data are needed to provide more precise evidence.

Abstract 428 Figure. Fig. 1

P43673D analysis of mitral annular reshape with third generation MitraClip XTr in functional and degenerative mitral regurgitation

The 3rd generation Mitraclip XTr was recently introduced to improve device performance, through longer clip arms that should allow better grasping of the mitral leaflets, thus improving coaptation and results eventually. Several studies have demonstrated additional effects such as the reshape of the mitral annulus immediately after clip implantation.

The aim of our study was to evaluate the mitral valve (MV) annular remodelling with MitraClip XTr.

Between March 2018 and November 2018, 75 consecutive patients were enrolled. The population was divided in two groups: functional mitral regurgitation (FMR) and degenerative mitral regurgitation (DMR).

The 3D MV datasets at baseline and immediately after the procedure were acquired and then analysed with semiautomatic MVQ software (QLAB Cardiac 3DQ v.10.0; Philips Medical Systems).

The software provides the following parameters: annular diameters (antero-posterior, AP, and inter-commissural, IC), circumference, area, height and ellipsicity (IC/AP ratio as percentage); saddle-index, defined as annular height to IC diameter ratio was derived.

The 3D post-processing was feasible in 54 patients (108 3D datasets): 28 had FMR (52%) and 26 had DMR (48%).

An average of 1.8 clips per patient were implanted: 2 clips in 38 (70%), 1 clip in 14 (26%) and 3 clips in 2 (4%) patients. The position was central in 93% of the procedures.

Results are reported in table 1. In the FMR group, a reduction in the AP diameter (p=0.001), an increase in both IC diameter (p=0.001) and annular ellipsicity (p<0.001) were observed.

In the DMR group, an increase in annular ellipsicity (p=0,008) and in saddle-index (p<0.05) were observed.

Table 1 Functional mitral regurgitation (N=28) Degenerative mitral regurgitation (N=26) Pre-clip Post-clip P-value Pre-clip Post-clip P-value IC diameter (mm) 39.3±4.2 41.9±4.1 0.001 40.9±6.5 41.8±5.8 0.257 AP diameter (mm) 32.8±4.6 30.4±3.2 0.001 32.6±4.8 31.7±4.5 0.199 Annular Height (mm) 5.1±1.8 5.4±1.8 0.336 4.8±1.9 5.7±2.2 0.026 3D circumference (mm) 122.7±15.1 123.5±11 0.718 123.5±19.0 124.0±17.1 0.812 3D area (mmq) 1128.0±280 1113.7±206 0.752 1160±346.7 1156.8±318.0 0.926 Annular ellipsicity (%) 121.5±12.2 138.5±11.8 0.0005 125.9±9.6 132.4±10.7 0.008 Saddle index 13.0±4 13.0±4 0.957 11.8±4.2 13.6±4.2 0.048

Our study demonstrates that the XTr implantation produces a MV annular remodelling both in FMR and DMR probably with different mechanisms. In FMR the MV annulus resulted more elliptical, wheras in DMR the geometrical modifications involve both the ellipsicity and the saddle-shape morphology.

P4728Prognostic implications of the relationship between effective regurgitant orifice area and left ventricle end diastolic volume in patients with functional mitral regurgitation treated with MitraClip

Background

The distinction between proportionate and disproportionate functional mitral regurgitation (FMR), based on the relationship between effective regurgitant orifice area (EROA) and left ventricle end diastolic volume (LVEDV), has recently been proposed as a possible new clinical and physiopathological concept to identify patients that could likely benefit from transcatheter mitral repair.

Purpose

The aim of our study was to explore the possible prognostic implications of the EROA/LVEDV ratio in patients with FMR treated with MitraClip.

Methods

Baseline EROA/LVEDV ratio was calculated in 72 patients with moderate-to-severe, symptomatic FMR treated with MitraClip. All patients underwent clinical, biochemichal and echocardiographic evaluation before MitraClip. EROA was calculated using PISA method. The primary outcome was a composite end-point of all-cause death or re-hospitalization for heart failure (HF).

Results

The median follow-up was 1 year. The primary outcome occurred in 25 patients (34.7%). The cut-off value of EROA/LVEDV ratio for primary outcome, identified by receiver operating characteristic curve, was 0.15 (p=0.007) with a sensitivity and specificity of 72 and 68%, respectively. Patients were divided in two groups according to the identified cut-off. Patients with higher ratio (Group I, n=35) presented a less dilated LV (LVEDVi: 113.2±33.4 mL vs 129.3±29.3 mL, p=0.033; LVESV: 140.7±49.0 mL vs 171.1±47.4 mL, p=0.010), a better LV systolic function (LVEF: 31.9±9.5% vs 27.8±5.8%, p=0.028) and a more severe MR (EROA: 44.5±12.9 mm2 vs 24.5±6.8 mm2, p<0.001; vena contracta: 7.4±1.5 mm vs 6.7±1.0 mm, p=0.045). Patients with lower ratio (Group II, n=37) showed a reduced prevalence of MV annular dilation (57.1% vs 91.7%, p=0.005) and a worse RV function (s'TDI: 9.2±2.2 cm/s vs 10.5±2.9 cm/s, p=0.039). At univariate analysis, EROA/LVEDV ratio >0.15 (HR = 2.467, 95% CI 1.017–5.982, p=0.046) and severe pulmonary hypertension (HR = 2.481, 95% CI 1.030–5.976, p=0.043) were associated with a worse clinical outcome. At multivariate Cox-regression analysis, both EROA/LVEDV ratio >0.15 and severe pulmonary hypertension were identified as independent predictors (HR 3.203, 95% CI 1–310–7.832, p=0.011; HR = 3.280, 95% CI 1.326–8.116, p=0.010, respectively).

Figure 1

Conclusion

Our data show that EROA/LVEDV ratio was an independent predictor of adverse clinical outcome in FMR patients treated with MitraClip. This preliminary experience shows that this index could help to identify subgroups of patients with potential different clinical benefits from MitraClip therapy. However, further and extended data are needed to provide more precise evidence.

Acknowledgement/Funding

None

P4385Diaphragm dysfunction following cardiac surgery: role of ultrasound imaging for initial and follow-up assessment during cardiac rehabilitation

Background

Diaphragm dysfunction is a common complication of cardiac surgery, often underdiagnosed. Ultrasonography (US) is a promising technique for diaphragmatic assessment. Few trials have been conducted using US after heart surgery and no clear data exist on the recovery of diaphragm function after cardiovascular rehabilitation (CR).

Purpose

The aim of this study is to evaluate post-cardiac surgery diaphragm dysfunction using US and to assess the impact of an inpatient CR programme on its functional recovery.

Methods

In a single-centre prospective cohort study 97 consecutive patients hospitalised in our CR Unit were enrolled. 14 patients underwent aortic valve replacement, 38 mitral valve repair or replacement, 14 coronary artery bypass grafting (CABG), 22 combined surgery, and 9 other surgical interventions. We performed diaphragm US at admission and after 10 rehabilitative sessions. The following parameters were assessed: thickening fraction (TF) in B-mode on the right intercostal projections, and excursion, time of inspiration, time of a respiratory cycle and contraction velocity in M-mode on right anterior subcostal projections.

Results

After cardiac surgery, the incidence of diaphragm dysfunction and paralysis were 60% and 1%, respectively. Patients with TF <20% at admission showed a significant improvement in TF (13.30%, IQR 8.69–17.39 vs 27.27%, IQR 21.05–31.58; p<0.001), excursion (1.67cm, IQR 1.3–2.1 vs 2.23cm, IQR 1.9–2.7; p<0.001), time of inspiration (0.9s, IQR 0.9–1.07 vs 1.01s, IQR 0.87–1.13; p=0.005), time of a respiratory cycle (2.67s, IQR 2.38–3.05 vs 3.07s, IQR 2.68–3.35; p<0.001) and velocity (1.81cm/s, IQR 1.14–2.33 vs 2.24cm/s, IQR 1.92–2.76; p<0.001). On the contrary, in patients with a TF>20%, no additional improvement was observed. In both groups, there was a significant improvement in the parameters of physical performance.

In particular, in the group with a TF<20%, the distance covered during the 6MWT (300m, IQR 205–370 vs 555m, IQR 450–612; p<0.001) and the energy cost of physical activity (2.60, IQR 2.13–2.92 vs 4.09, IQR 3.44–4.50; p<0.001) increased while the perception of exertion (Borg Scale 11, IQR 11–13 vs 13, IQR 12–13; p=0.011) was reduced. At the 10th day assessment, 51.5% of the total population had a recovery of diaphragm function, whilst 48.5% had a failure of recovery (TF relative change between admission and discharge <60%). The multivariate analysis identified CABG as an independent predictor of failure of diaphragm recovery (OR 5.44; CI 1.10–26.84, p=0.037).

Conclusion

US might be a valuable part of routine clinical practice for initial and follow-up assessment of patients after open-heart surgery. CR showed to be an effective strategy to improve diaphragm parameters in patients with post-surgical dysfunction. Progressive evaluation of diaphragm function may drive personalised rehabilitation programmes.

P2522A new scoring system to stratify post-surgical valvular patients during cardiovascular rehabilitation: derivation and validation study

Background

Guidelines underline the importance of Cardiovascular Rehabilitation (CR) in post-surgical valvular patients both for the functional recovery and the monitoring of complications. However, there are no established indicators to better categorise their risk and to identify the real probability of recovery.

Purpose

The aim of this study is to propose and validate a scoring system to appropriately stratify post-surgical valvular patients in order to individualise CR programmes.

Methods

A retrospective study was conducted on 1480 post-surgical valvular patients hospitalized in our CR Unit (902 M – 578 F; median age of 64 years, IQR 53–73). 485 patients underwent single heart valve repair, 408 single heart valve replacement, 237 single heart valve surgery and additional interventions, 249 multiple valve interventions and 101 multiple heart valves and additional interventions. Subjects were randomised in two groups for data analysis: a Derivation (D; n=1000) and a Validation (V; n=480) group. Initially, in group D we assessed the predictive value of anamnestic, clinical and laboratory variables for major complications and functional recovery. We created two scoring systems for these outcomes and, subsequently, we validated them on group V. Finally, we interlaced them in an operative algorithm.

Results

Chronic kidney disease (OR 2.588; 95% CI 1.232–5.436; p=0.012), sternal surgical re-synthesis (OR 7.757; 95% CI 2.042–29.471; p=0.003), post-surgical transfusions (OR 2.419; 95% CI 1.407–4.161; p=0.001) and Troponin T peak >1400 μg/L (OR 2.441; 95% CI 1.418–4.200; p=0.001) were independent predictors for the occurrence of major complications in group D. Age (OR 0.958; 95% CI 0.9339–0.977; p<0.001), post- surgical transfusions (OR 1.981; 95% CI 1.160–3.380; p<0.001) and METS at admission (OR 0.032; 95% CI 0.017–0.061; p<0.001) were independent predictors of a higher functional recovery in group D. When the two scoring systems were validated on group V, we obtained a z score of 0.07 (p=0.941) for the major complications risk score and a z score of 1.23 (p=0.219) for the functional recovery stratification system, respectively, indicating a very reliable model. We proceeded to build an operative algorithm to stratify patients and propose personalised CR strategies.

Conclusions

We identified predictors to stratify the risk of complications and to define the probability of recovery in post-surgical valvular patients undergoing CR. The proposed final operative algorithm may be a unique tool to support the cardiologist to tailor rehabilitation programmes. This may lead to better outcomes and reduction of healthcare expenditure with optimisation in the use of available resources.

Acknowledgement/Funding

None

Intra-procedural monitoring protocol using routine transthoracic echocardiography with backup trans-oesophageal probe in transcatheter aortic valve replacement: a single centre experience

Aim

The aim of this study is to describe our 9-year experience in transcatheter aortic valve replacement (TAVR) using transthoracic echocardiography (TTE) as a routine intra-procedural imaging modality with trans-oesophageal echocardiography (TEE) as a backup.

Methods and results

From January 2008 to December 2017, 1218 patients underwent transfemoral TAVR at our Institution. Except the first 20 cases, all procedures have been performed under conscious sedation, with fluoroscopic guidance and TTE imaging monitoring. Once the TTE resulted suboptimal for final result assessment or a complication was either suspected or identified on TTE, TEE evaluation was promptly performed under general anaesthesia. Only 24 (1.9%) cases required a switch to TEE: 6 cases for suboptimal TTE prosthetic valve leak (PVL) quantification; 12 cases for haemodynamic instability; 2 cases for pericardial effusion without haemodynamic instability; 4 cases for urgent TAVR. The 30-days and 1-year all-cause mortality were 2.1% and 10.2%, respectively. Cardiac mortality at 30-days and 1-year follow-up were 0.6% and 4.1%, respectively. Intra-procedural and pre-discharge TT evaluation showed good agreement for PVL quantification (k agreement: 0.827, P = 0.005).

Conclusion

TTE monitoring seems a reasonable imaging tool for TAVR intra-procedural monitoring without delay in diagnosis of complications and a reliable paravalvular leak assessment. However, TEE is undoubtedly essential in identifying the exact mechanism in most of the complications.

Effects of chronic elevation of atrial natriuretic peptide and free fatty acid levels in the induction of type 2 diabetes mellitus and insulin resistance in patients with mitral valve disease

BACKGROUND AND AIMS

The relationship between atrial natriuretic peptide (ANP), increased free fatty acid (FFA) and insulin resistance in patients with mitral valve disease (MVD), a group characterised by elevated atrial pressure and increased ANP levels, is not defined. The present study was performed to evaluate, in MVD patients, the relationship between increased ANP and FFA levels and insulin resistance and the role of mitral valve replacement/repair in ameliorating these metabolic alterations. Conversely, coronary heart disease (CHD) patients were evaluated before and after coronary artery bypass grafting (CABG), since they are known to be insulin resistant in the presence of chronic FFA increase.

METHODS AND RESULTS

Fifty MVD patients and 55 CHD patients were studied before and 2 months after surgery and compared with 166 normal subjects. Before surgery, 56% of MVD patients had impaired glucose tolerance or newly diagnosed type 2 diabetes after a standard oral glucose load and this percentage decreased to 46% after surgery. In CHD, impaired glucose tolerance (IGT) or newly diagnosed type 2 diabetic patients were 67% of patients before and after CABG. In MVD, left atrial (LA) volume, ANP, FFA incremental area and insulin levels were higher and Insulin Sensitivity (IS) index significantly reduced while after surgery, LA volume, ANP and FFA significantly decreased and IS index significantly improved. In CHD, insulin resistance and hyperinsulinaemia were present both before and after surgery with increased tumour necrosis factor (TNF)-α and interleukin (IL)-6 levels.

CONCLUSION

In MVD, a higher degree of abnormal glucose tolerance and insulin resistance are associated to increased levels of ANP and FFA, while these metabolic alterations are improved by mitral valve replacement/repair surgery. Clinical Trial.gov registration number NCT 00520962.

Characterization of innate responses elicited by neoadjuvant radio-chemotherapy for rectal cancer

e15044

Background: The neoadjuvant chemo-radiotherapy (CT-RT) has improved the treatment of locally advanced rectal cancer reducing the local recurrence. However a survival benefit has not been reached yet. In order to increase the rate of pathological complete remissions in our Institution we intensified both the CT schedule adding oxaliplatin to 5-FU and the RT program with tomotherapy. The aim of this study was to verify: whether the pattern of innate response elicited by the neoadjuvant CT-RT is heterogeneous among pts and whether this information can be used to identify which pts will benefit from the treatment. Methods: We collected samples of T3N+M0 rectal cancer pts before, during and after neoadjuvant CT-RT (3 cycles of oxaliplatin + 5-FU; 45 Gy). At each time point we characterized circulating monocytes by flow cytometry, infiltrating macrophages by immunoistochemistry (IHC) and selected inflammatatory molecules by ELISA.Results: We recruited so far 25 pts, of whom 10 have reached the surgery with three pathological complete remission and four down staging. No substantial changes were detectable in the number of circulating monocytes. In contrast we observed a clear expansion of CD14/CD86 and CD14/CD163 double positive subsets. This event was transient and apparently causally related to the treatment since it abated at the later time point. Moreover, it correlated with sensitivity to the treatment: 5/7 pts who underwent disease regression had an early and transitory increase of the number of CD14/CD86 and CD14/CD163 positive cells, which was absent or negligible in non responder pts. The IHC study revealed a massive tumoral infiltration by macrophages which displayed clear features of alternative M2 polarization as assessed by expression of the CD163 and 206 scavenger receptors. A subset of pts had elevated PTX3 and low CRP concentration at the onset of treatment. PTX3 concentration abated after the first CT cycle. Conclusions: These data suggest that neoadjuvant CT-RT modulates the cellular components of innate immune responses, that could represent valuable predictive factors.

No significant financial relationships to disclose.

[Acute renal failure after videolaparoscopic surgery: an avoidable complication?]

Videolaparoscopic surgery exposes the abdominal organs to the mechanical effect of pneumoperitoneum at pressure values between 12 and 15 mm Hg, which are considered safe. Nevertheless, experimental data have shown that this pressure range can represent a hemodynamic risk factor as it may induce a decrease in the venous return to the right ventricle, a decrease in cardiac output, and activation of the sympathetic nervous system and renin angiotensin system. We report two cases of acute renal failure that occurred soon after videolaparoscopy in young female patients without any evidence of ongoing renal disease. Patient A was 29 years old and was submitted to videolaparoscopic surgery in a follow-up program after surgical treatment of ovarian cancer; patient B was 15 years old and was submitted to the surgical removal of a monolateral ovarian cyst. In neither of the cases was it necessary to perform hemodialysis. Patient A underwent a renal biopsy under ultrasound guidance; optic microscopy showed only in ra- and extraglomerular capillary congestion. In both cases the acute renal failure resolved completely and the patients where discharged with normal renal function. Taking in to account that normal renal venous pressure levels are around 4 mmHg we think that a) a 15 mmHg pneumoperitoneum may represent a risk factor during videolaparoscopic surgery mainly if the patient's extracellular volume is not properly expanded; b) administration of nonsteroidal anti-inflammatory drugs in order to prevent surgical pain may inhibit vasodilatory prostaglandin availability; c) onset of oliguria during the surgical procedure suggests that extracellular volume expansion is required.

[Treatment of arterial hypertension in diabetic nephropathy. Certainties and hypotheses]

Clinical observation has long emphasized the importance of arterial hypertension in the course of diabetic nephropathy and recent studies suggest that hypertension might play a decisive pathogenetic role in the course of the disease, hence the necessity of correcting the hypertension of diabetic patients has by now been universally accepted. There is, however, still some uncertainty concerning the usefulness of acting preventively on so-called microhypertension; in other words, whether early antihypertensive drug treatment can prevent diabetic nephropathy. This paper discusses the criteria to be followed in the choice of antihypertensive medication during diabetic nephropathy giving special attention to pathophysiological considerations. Moreover, it also discusses the effects of antihypertensive drugs currently regarded as first-choice agents, i.e. calcium antagonists and the angiotensin converting enzyme inhibitors, on intrarenal hemodynamics.

Minimal change nephrotic syndrome with cecum adenocarcinoma

Membranous glomerulonephritis is the most common glomerular disease associated with malignancy, the association of minimal change glomerulopathy with solid tumor is still uncommon. We report a 72-year-old man with nephrotic syndrome due to minimal change glomerular disease; an accurate seek of underlying malignancy revealed a cecum adenocarcinoma. We had a complete remission of nephrotic syndrome after surgery of carcinoma.

The PTH-calcium relationship curve in secondary hyperparathyroidism, an index of sensitivity and suppressibility of parathyroid glands

A sigmoidal relationship, fitting a four-parameter model, has been demonstrated in in vivo and in vitro studies to link the parathyroid hormone (PTH) secretion rate and calcium concentration changes. In uraemic patients different patterns of calcium-mediated PTH secretion were reported in different types of renal bone diseases and a shift to the right and a steeper slope has been observed in secondary hyperparathyroidism. To gain more information that could predict indexes for successful medical therapy we investigated the calcium-PTH sigmoidal relationship in 42 hyperparathyroid patients with different degrees of secondary hyperparathyroidism; we classified as moderate those patients presenting basal PTH (PTHbas) < 600 pg/ml and bone alkaline phosphatase (AP) < 500 U/l, and severe those with a PTHbas > or = 600 pg/ml and bone AP > or = 500 U/l. Changes in ionized calcium (iCa) were induced by calcium-free dialysis on the first day, to induce hypocalcaemia up to serum iCa 3.5 mEq/l, and calcium 8 mEq/l dialysis on the third day, to induce hypercalcaemia. The moderate hyperparathyroidism patients had PTHmax, PTHmin and slope, calculated in absolute values and relative values, lower than severe hyperparathyroidism patients but they did not differ in the minimal to maximal PTH ratio. In the moderate group the PTHbas correlated with all the curve parameters except PTHmin, calculated both in absolute and percentage values, while in the severe group PTHmin was the only parameter correlating to the PTHbas. In conclusion, by performing the dynamic test, we found that some glands were not suppressible among moderate hyperparathyroidism patients.

Thrombospondin and transforming growth factor-beta 1 increase expression of urokinase-type plasminogen activator and plasminogen activator inhibitor-1 in human MDA-MB-231 breast cancer cells

BACKGROUND

Thrombospondin is a high molecular weight adhesive glycoprotein that has been shown to function in mechanisms of tumor progression. The authors' previous studies have shown that thrombospondin promotes human lung carcinoma invasion by up-regulation of the plasminogen activator system through a mechanism involving the activation of transforming growth factor-beta 1 (TGF-beta 1). In this study, a similar thrombospondin-mediated mechanism operative in breast carcinoma cells is described.

METHODS

The effect of thrombospondin and TGF-beta 1 on the capacity of a line of breast carcinoma cells to activate plasminogen was measured as well as the physiologic consequences of these activities on cell adhesion and proliferation. Plasminogen activation was assessed by measuring the plasmin activity and plasminogen activator inhibitor-1 (PAI-1) levels in cell-conditioned media and the cell-associated urokinase-type plasminogen activator (uPA) levels.

RESULTS

Treatment of MDA-MB-231 breast carcinoma cells with either thrombospondin or TGF-beta 1 caused increased secretion of PAI-1 with a concomitant decrease in plasmin activity, whereas cell-associated uPA expression was increased with respect to controls. Thrombospondin (40 micrograms/ml) or TGF-beta 1 (5 ng/ml) stimulated the cells to secrete 5.5- and 6.7-fold more PAI-1 than controls, respectively, and caused decreased plasmin activity in the cell culture medium. Conversely, either thrombospondin (40 micrograms/ml) or TGF-beta 1 (5 ng/ml) caused the cells to express 4.55- and 5.38-fold more uPA than controls, respectively. Thrombospondin and TGF-beta 1 induced a more flattened and spread appearance in the cells with no effect on proliferation. These effects could be reversed with antibodies to either thrombospondin or TGF-beta 1 and were not due to contamination of thrombospondin with active TGF-beta 1.

CONCLUSIONS

Thrombospondin and TGF-beta 1 function similarly to increase cell-associated uPA and cell-secreted PAI-1. These data suggest that thrombospondin may not only function as an adhesive molecule, but through a mechanism involving the activation of TGF-beta 1, may modulate cell surface protease expression. In addition, these observations suggest that thrombospondin and TGF-beta 1 could promote metastasis by increasing uPA-mediated cell invasion, whereas through the action of PAI-1, also protect blood-born tumor emboli from destruction by host fibrinolytic enzymes.

Thrombospondin (TSP) and transforming growth factor beta 1 (TGF-beta) promote human A549 lung carcinoma cell plasminogen activator inhibitor type 1 (PAI-1) production and stimulate tumor cell attachment in vitro

A growing body of evidence has recently implicated TSP and TGF-beta in the process of malignancy, such as tumor cell proliferation, tumor angiogenesis, and metastasis. The purpose of the present study was to evaluate potential mechanisms of TSP and TGF-beta in tumor cell attachment and invasion. Our results indicate that both TSP and TGF-beta promoted tumor cell attachment and spreading in the presence of plasminogen. The mechanism for these effects appeared to be due, in part, to the capacity of TSP and TGF-beta to induce tumor cell production of (PAI-1). PAI-1, which is a natural inhibitor of tumor-cell associated urokinase-type plasminogen activator (uPA) activity, inhibited activation of plasminogen to plasmin in the growth media, thereby preventing plasmin-induced detachment of cells. The TSP-promoted production of PAI-1 could be inhibited not only by anti-TSP antibodies but also by a neutralizing antibody against TGF-beta. These results suggest that TSP by a mechanism involving TGF-beta can promote cell adhesion through stimulation of tumor cell secretion of PAI-1. These data provide evidence that TSP not only has the capacity of functioning as a matrix protein to directly promote cell-substratum adhesion but that TSP can also stimulate cell adhesion and spreading by modulating cell surface protease expression through stimulation of tumor-associated production of PAI-1.

Chemical parathyroidectomy for recurrence of secondary hyperparathyroidism

To avoid the risks of reoperation, we treated 15 uremic patients on regular extracorporeal dialysis and affected by hyperparathyroidism recurring after subtotal parathyroidectomy with ultrasound-guided ethanol injection. Follow-up was extended to 12 months after the last injection and for 11 patients to 24 months. Plasma parathyroid hormone concentration, as measured with a carboxyterminal parathyroid hormone (c-PTH) radioimmunoassay (normal, 0.2 to 2 ng/mL), significantly decreased from a basal value of 19.29 +/- 14.73 ng/mL to 11.19 +/- 9.54 ng/mL at 1 month, 7.45 +/- 4.99 ng/mL at 6 months, 6.91 +/- 4.71 ng/mL at 12 months, and 6.51 +/- 3.89 ng/mL at 24 months. Total and bone alkaline phosphatase decreased in parallel. The only remarkable side effect was transient dysphonia, which occurred in two cases. These data suggest that the technique of ultrasound-guided fine-needle ethanol injection might be a valuable alternative to surgery for recurrent hyperparathyroidism after subtotal parathyroidectomy in selected patients. This should be confirmed in larger series of patients and with a more prolonged follow-up.

Myocardial revascularization with bilateral internal thoracic artery in patients with left main disease: an incremental risk?

Although the long-term patency of the internal thoracic artery (ITA) has been well proved, there is still some concern about its preoperative performance. We considered 80 patients with left main disease (mean age 60.2 years) who underwent coronary artery bypass grafting in our institute from March 1988 to September 1992. Patients with left main disease were divided into 2 groups: group I-38 patients receiving only ITA grafts on the left coronary system and group II-42 patients having a single ITA graft together with saphenous vein grafts on the left coronary system. No patients in group I received a saphenous graft on the left coronary system and three patients with right coronary artery involvement received total arterial myocardial revascularization with the use of the inferior epigastric artery. Perioperative complications in group I and group II patients were, respectively: myocardial necrosis in 2 (6.9%) and 3 (8.8%), use of intraaortic balloon pump in 2 (6.9%) and 2 (5.9%). No death occurred in either group. In our experience, the use of bilateral ITA grafts in patients with left main stenosis was not related to an incremental risk. We conclude that left main disease should not be considered as counterindication to the extensive use of arterial conduits.

Rest and exercise hemodynamics of stentless porcine bioprostheses in aortic position

Mechanical and conventional stented bioprostheses, because of need for anticoagulants, hemodynamic characteristics and long-term durability, do not represent the optimal heart valve replacement device. In this study we compared the hemodynamic function of a stented aortic bioprosthesis (St Jude Bioimplant), implanted in 10 patients, with a stentless porcine aortic bioprosthesis (Biocor) implanted in 7 patients, by means of Doppler echocardiography early postoperative at rest (T1) and 6 months later at rest (T2a) and during exercise (T2b). Mean and peak systolic gradients across stentless porcine prostheses were significantly lower than across stented bioprostheses (T1 p = 0.008 and p = 0.004; T2a p < 0.0001 and p < 0.0001; T2b p < 0.0001 and p < 0.0001, respectively). Our results show that systolic and diastolic mechanical stress on biological components of a glutaraldehyde-fixed stentless porcine aortic bioprosthesis is much lesser than on stented bioprostheses. This feature has appeared evident at rest and much more after exercise testing. The reduction of systolic and diastolic stress is expected to determine lower calcification degree and longer durability of stentless porcine aortic bioprostheses. Moreover, aortic valve replacement by means of stentless bioprostheses allows the implantation of a 1 size (2 mm) larger device, appearing favourable especially in small aortic annulus. On the basis of these promising results we suggest that stentless bioprostheses are a valid alternative to stented bioprostheses for aortic valve replacement. However, patient population is too small and the follow-up is too short to draw a definite statement about long-term hemodynamic performance of this device.

[The treatment of arterial hypertension in diabetes mellitus. Choices and problems]

Recent studies indicate that arterial hypertension in diabetes mellitus is a paramount pathogenetic step in the evolution and acceleration of diabetic macro- and microangiopathy and in particular in the development of nephropathy and uremia. This paper deals with the clinical problems of antihypertensive treatment in diabetic patients and discusses the antihypertensive repertory with the aim at determining the best drug choice in the individual case. In the light of our present pathophysiologic knowledges of the intrarenal effects of the various classes of antihypertensive drugs the possibility of preventing diabetic nephropathy is discussed.

[Diabetic nephropathy and arterial hypertension: the physiopathological aspects and antihypertensive treatment]

The purpose of our review is to delineate the pathogenic steps linking arterial hypertension in diabetes to diabetic nephropathy. The results of recent studies suggest that arterial hypertension in diabetes might lay a decisive pathogenetic role in the evolution of diabetic nephropathy: the existence of a higher ratio of erythrocytic Na/Li counter-transport in nephropathic diabetics as well as higher pressure values in the parents of diabetics who develop nephropathy indicates that hypertension may be casually related to renal complications. Diabetes-associated hypertension involves the modification of two important pressure- regulation factors: 1. an alteration in extracellular volume and increased renal absorption of sodium which leads to an expanded pool; 2. increased cardiovascular reactivity to norepinephrine and angiotensin II, an effect which might be related to increased intracellular calcium. Hyperfiltration seems to be present at the onset of diabetes, and arterial hypertension increases the transglomerular pressure gradient which is thought to play an important role in the pathogenesis of kidney damage. Antihypertensive drugs such as ACE-inhibitors and calcium channel blockers tend to protect the regulation of renal function. This could be explained by the fact that ACE-inhibitors suppress the trophic effects of angiotensin II on the nephron, while calcium channel blockers might interfere with intracellular processes involved in cell hypertrophy that require the interaction of calcium ions. In the management of diabetes prevention of diabetic nephropathy requires early and careful correction of diabetes-associated hypertension. We discuss the major groups of antihypertensive drugs, their metabolic side-effects and intrarenal induced hemodynamic changes.

Ultrasound-guided percutaneous fine-needle ethanol injection into parathyroid glands in secondary hyperparathyroidism

To reduce parathyroid hormone concentrations in uraemic patients refractory or hyporesponsive to calcium supplements and active metabolites of vitamin D, we developed in 1982 a new parathyroid ablative technique consisting of percutaneous fine-needle ethanol injection (PFNEI) into enlarged parathyroid glands under ultrasonic guidance. Fifty uraemic patients have been treated. Decreases in carboxy terminal parathyroid hormone (PTH) were 50% or more in 13 of 50 patients followed up (26%) at 1 month, in 13 of 48 (27%) at 6 months, and in 9 of 25 (36%) at 12 months. Decreases of 30% or more in PTH were obtained in 21 of 50 (42%), in 25 of 48 (52%), and in 15 of 25 (60%). In 'responsive' patients, serum total alkaline phosphatase was significantly reduced [from 579 +/- 645 U/l to 360 +/- 354 U/l (P less than 0.01) at 6 months, and to 273 +/- 311 U/l (P less than 0.01) at 12 months] and bone isoenzyme decreased similarly [from 482 +/- 608 U/l to 256 +/- 344 U/l (P less than 0.005), and to 225 +/- 354 U/l (P less than 0.01)]. The best results were in seven patients who had relapsed after subtotal parathyroidectomy. Declines in PTH of 30% or more were observed in four of seven patients at 1 month, in six of the seven (85%) at 6 months, and in all four patients seen after 12 months. The treatment corrected hypercalcaemia, making it possible to start or to increase daily vitamin D treatment. Side-effects were mild, rare, and transient.

Bone mineral and aluminum concentrations in patients undergoing CAPD

CAPD results in continuous peritoneal transfer of hormones and minerals involved in the pathogenesis of renal osteodystrophy (RO). Moreover, although CAPD patients seem to have better control of serum phosphate concentration than hemodialysis patients, the need for aluminum-containing phosphate binders (ACPB) may still be present. In a prospective study meant to investigate the evolution of RO, we obtained 79 bone biopsies in 29 uremic patients (20 male, 9 female; age 25-59, mean 46). Of these, 22 were obtained at the beginning of treatment, 24 after 24 months, 23 after 36 months and 10 after 60 months. All patients were treated with CAPD (Viaflex, Baxter 2-2.5 L x 4-5 bags/day; Ca(++) + 3.5, Mg(++) 1.5 mEq/L) as the first modality of therapy and received oral calcitriol, aluminum hydroxyde and/or calcium carbonate and magnesium hydroxyde in order to maintain serum calcium (Ca) and phosphorus within the normal range. Qualitative bone histology, bone Ca and magnesium (Mg) (Flame atomic absorption spectroscopy) and aluminum (Al) concentration (Graphite furnace atomic absorption spectrometry) were determined. CAPD achieves a good control of RO as indicated by the tendency toward a decreased incidence of mixed osteodystrophy and predominant hyperparathyroid bone disease and improvement of osteoid lesions. A defective Ca content of bone is persistent in the observed period and positively correlated to bone Mg concentration. An increased level of Al was shown in the serum and bone. The highest bone Al content was found among patients with predominant osteoid bone disease. Also in CAPD, patients consuming ACPB are at risk of bone Al accumulation despite the low Al levels in the dialysate.

[The pathogenesis of arterial hypertension in diabetes mellitus and its role in nephropathy]

This paper synthesizes the pathogenic steps of arterial hypertension in diabetes mellitus: hyperosmolarity due to the hyperglycemia and increased sodic tubular reabsorption accounting for the expansion of the extracellular volume with hypervolemia; abnormalities of the ionic membrane pumps leading to abnormal intracellular calcium distribution, thereby inducing an increased vascular tone; atypical vasomotor reactivity to cathecolamines; modifications of the renin-angiotension-aldosterone system. The pathophysiological derangements by which hypertension could induce nephropathy are examined: the vasodilatation which can be detected from the onset of diabetes, may be a determinant in the transmission of systemic hypertension to the glomerular microcirculation with resulting enhancement of the hydrostatic transglomerular pressure gradient (i.c. the major factor producing glomerular injury), glomerular plasmatic flow and filtration rate. The nephron hyperfiltration increases the movement of plasmatic proteins across the glomerular capillary wall with subsequent mesangial hyperactivity and sclerosis. Antihypertensive treatment in diabetes follows general guidelines and it should be instituted even in the case of microhypertension being facilitated in this setting the appearance of microalbuminuria i.e. the starting point of nephropathy. Even if experimental studies are to favor ACE inhibitors as the first-line drugs for abating glomerular hypertension by mitigation of the direct effect of angiotensin II on the efferent arteriolar tone, clinical observations suggest that, regardless of type of treatment, the normalization of systemic arterial pressure, by reversing glomerular hypertension may be effective in preventing diabetic nephropathy.

[Current approach in the prevention and treatment of diabetic nephropathy]

Diabetic renal microangiopathy accounts for enormous morbidity and mortality, particularly in patients who develop diabetes in childhood or early youth; in the last few years its pathogenesis has been therefore extensively studied, aiming to prevent renal complications or at least of slowing down its progression toward uremia. Though not always in accordance with theoretical expectations, the results of clinical trials have nevertheless widened our therapeutic possibilities; in fact, besides the attainment of an optimal metabolic control, other possible interventions include a careful correction of albeit minimal elevations in arterial pressure; the interference with intrarenal hemodynamic parameters; the correction of insulin-independent metabolic pathways, abnormally activated in the diabetic, such as non enzymatic glycation and polyol pathway; the treatment of endothelial and platelet alterations; the improvement of the rheologic properties of blood.

Particle migration from haemodialysis circuit: electron microscopy and microprobe analysis

It has been recognized that storage inflammation in organs of uraemic patients is due to silicone particle migration from tubing segments of the haemodialysis circuit to blood. Nevertheless, iatrogenic storage of foreign material containing Si has been also observed in long-term dialysis patients which, in our Unit, used only PVC or PU-PVC tubings. The origin and the nature of the particulate has been investigated in vivo and in vitro on bioptical samples as well as on cuprophan dialyser and PVC tubing eluates. This study carried out by means of TEM, SEM and microprobe EDS revealed the presence of variously shaped material and particles containing Si in bioptical samples and in eluates. Si containing contaminants were not demonstrated in eluates filtered in absence of the dialyser. This result suggests that leachable products can result from the dialyser and that such release can be an additional risk for uraemic patients.