Procedural success in transaxillary transcatheter aortic valve implantation according to type of transcatheter heart valve: results from the multicenter TAXI registry

BACKGROUND

Transaxillary (TAx) transcatheter aortic valve implantation (TAVI) is a preferred alternative access in patients ineligible for transfemoral TAVI.

AIMS

This study used the Trans-AXillary Intervention (TAXI) registry to compare procedural success according to different types of transcatheter heart valves (THV).

METHODS

For the TAXI registry anonymized data of patients treated with TAx-TAVI were collected from 18 centers. Acute procedural, early and 1-month clinical outcomes were adjudicated in accordance with standardized VARC-3 definitions.

RESULTS

From 432 patients, 368 patients (85.3%, SE group) received self-expanding (SE) THV and 64 patients (14.8%, BE group) received balloon-expandable (BE) THV. Imaging revealed lower axillary artery diameters in the SE group (max/min diameter in mm: 8.4/6.6 vs 9.4/6.8 mm; p < 0.001/p = 0.04) but a higher proportion of axillary tortuosity in BE group (62/368, 23.6% vs 26/64, 42.6%; p = 0.004) with steeper aorta-left ventricle (LV) inflow (55° vs 51°; p = 0.002) and left ventricular outflow tract (LVOT)-LV inflow angles (40.0° vs 24.5°; 0.002). TAx-TAVI was more often conducted by right sided axillary artery in the BE group (33/368, 9.0% vs 17/64, 26.6%; p < 0.001). Device success was higher in the SE group (317/368, 86.1% vs 44/64, 68.8%, p = 0.0015). In logistic regression analysis, BE THV were a risk factor for vascular complications and axillary stent implantation.

CONCLUSIONS

Both, SE and BE THV can be safely used in TAx-TAVI. However, SE THV were more often used and were associated with a higher rate of device success. While SE THV were associated with lower rates of vascular complications, BE THV were more often used in cases with challenging anatomical circumstances.

Long Stent Implantation on the Left Anterior Descending Coronary Artery at a Follow-Up of More Than Five Years

BACKGROUND

Stent implantation represents the standard of care in coronary intervention. While a short stent implanted on a focal lesion located on the left anterior descending artery (LAD) seems a reasonable alternative to an internal mammary implant, the same for long stents is still debated.

METHODS

We reported the long-term data of 531 consecutive patients who underwent Percutaneous Coronary Intervention (PCI) with long stents in two highly specialized centres. The main inclusion criteria were the implantation of stents longer than 30 mm on the LAD and a minimum follow-up (FU) of five years. The primary endpoint was mortality, and the secondary endpoints were any myocardial infarction (MI), target vessel and lesion revascularization (TVR and TLR, respectively), and stent thrombosis (ST) observed as definite, probable, or possible.

RESULTS

In this selected population with characteristics of complex PCI (99.1%), the long-term follow-up (mean 92.18 ± 35.5 months) estimates of all-cause death, cardiovascular death, and any myocardial infarction were 18.3%, 10.5%, and 9.3%, respectively. Both all-cause and cardiovascular deaths are significantly associated with three-vessel disease (HR 6.8; confidence of interval (CI) 95% 3.844-11.934; p < 0.001, and HR 4.7; CI 95% 2.265-9.835; p < 0.001, respectively). Target lesion (TLR) and target vessel revascularization (TVR) are associated with the presence of three-lesion disease on the LAD (HR 3.4; CI 95% 1.984-5.781; p < 0.001; HR 3.9 CI 95% 2.323-6.442; p < 0.001, respectively). Re-PCI for any cause occurred in 31.5% of patients and shows an increased risk for three-lesion stenting (HR 4.3; CI 95% 2.873-6.376; p < 0.001) and the treatment of bifurcation with two stents (HR 1.6; 95% CI 1.051-2.414; p = 0.028). Stent thrombosis rate at the 5-year FU was 4.4% (1.3% definite; 0.9% probable; 2.1% possible), including a 1.7% rate of very-late thrombosis. The stent length superior to 40 mm was not associated with poor outcomes (all-cause death p = 0.349; cardiovascular death p = 0.855; MI p = 0.691; re-PCI p = 0.234; TLR p = 0.805; TVR p = 0.087; ST p = 0.189).

CONCLUSION

At an FU of longer than five years, patients treated with stents longer than 30 mm in their LAD showed acceptable procedural results but poor outcomes.

Chest CT opportunistic biomarkers for phenotyping high-risk COVID-19 patients: a retrospective multicentre study

OBJECTIVE

To assess the value of opportunistic biomarkers derived from chest CT performed at hospital admission of COVID-19 patients for the phenotypization of high-risk patients.

METHODS

In this multicentre retrospective study, 1845 consecutive COVID-19 patients with chest CT performed within 72 h from hospital admission were analysed. Clinical and outcome data were collected by each center 30 and 80 days after hospital admission. Patients with unknown outcomes were excluded. Chest CT was analysed in a single core lab and behind pneumonia CT scores were extracted opportunistic data about atherosclerotic profile (calcium score according to Agatston method), liver steatosis (≤ 40 HU), myosteatosis (paraspinal muscle F < 31.3 HU, M < 37.5 HU), and osteoporosis (D12 bone attenuation < 134 HU). Differences according to treatment and outcome were assessed with ANOVA. Prediction models were obtained using multivariate binary logistic regression and their AUCs were compared with the DeLong test.

RESULTS

The final cohort included 1669 patients (age 67.5 [58.5-77.4] yo) mainly men 1105/1669, 66.2%) and with reduced oxygen saturation (92% [88-95%]). Pneumonia severity, high Agatston score, myosteatosis, liver steatosis, and osteoporosis derived from CT were more prevalent in patients with more aggressive treatment, access to ICU, and in-hospital death (always p < 0.05). A multivariable model including clinical and CT variables improved the capability to predict non-critical pneumonia compared to a model including only clinical variables (AUC 0.801 vs 0.789; p = 0.0198) to predict patient death (AUC 0.815 vs 0.800; p = 0.001).

CONCLUSION

Opportunistic biomarkers derived from chest CT can improve the characterization of COVID-19 high-risk patients.

CLINICAL RELEVANCE STATEMENT

In COVID-19 patients, opportunistic biomarkers of cardiometabolic risk extracted from chest CT improve patient risk stratification.

KEY POINTS

• In COVID-19 patients, several information about patient comorbidities can be quantitatively extracted from chest CT, resulting associated with the severity of oxygen treatment, access to ICU, and death. • A prediction model based on multiparametric opportunistic biomarkers derived from chest CT resulted superior to a model including only clinical variables in a large cohort of 1669 patients suffering from SARS- CoV2 infection. • Opportunistic biomarkers of cardiometabolic comorbidities derived from chest CT may improve COVID-19 patients' risk stratification also in absence of detailed clinical data and laboratory tests identifying subclinical and previously unknown conditions.

Stroke volume index and transvalvular flow rate trajectories in severe aortic stenosis treated with TAVR

AIMS

The prognostic impact of flow trajectories according to stroke volume index (SVi) and transvalvular flow rate (FR) in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) remains poorly assessed. We evaluated and compared SVi and FR prior and after TAVR for severe AS.

METHODS AND RESULTS

Patients were categorized according to SVi (<35 mL/m2) and FR (<200 mL/s). The association of pre- and post-TAVR SVi and FR with all-cause mortality up to 3 years was assessed with multivariable Cox regression models. Among 980 patients with pre-TAVR flow assessment, SVi was reduced in 41.3% and FR in 48.1%. Baseline flow status was not an independent mortality predictor [SVi: hazard ratio (HR) 1.22, 95% confidence interval (CI) 0.85-1.82, FR: HR 0.78, 95% CI 0.48-1.27]. Among 731 patients undergoing early (5 days, interquartile range 2-29) post-TAVR flow assessment, SVi recovered in 40.1% and FR in 49.0% patients with baseline low flow. Reduced FR following TAVR was an independent predictor of mortality (HR 1.67, 95% CI 1.02-2.74), whereas SVi was not (HR 0.97, 95% CI 0.53-1.78). Three-year estimated mortality in patients with recovered FR was lower than that in patients with reduced FR (13.3 vs. 37.7% vs, P = 0.003) and similar to that in patients with normal baseline FR (P = 0.317).

CONCLUSION

Baseline flow status was not an independent predictor of mid-term mortality among all-comers with severe AS undergoing TAVR. Flow recovery early after TAVR was frequent. Post-TAVR FR, but not SVi, was independently associated with mid-term all-cause mortality. By impacting flow status, AV replacement modifies the association of flow status with outcomes.

Nurse-led distal radial access: efficacy, learning curve, and perspectives of an increasingly popular access. Does learning by doing apply to both the doctor and the nurse?

BACKGROUND

The distal radial represents an evolution of the standard radial approach. Distal radial arterial access (DRA) in the so-called "anatomical snuffbox" is technically more difficult but offers potential advantages for patients. Moreover, the use of the distal radial would preserve the proximal radial from the risk of arterial occlusion after interventional procedures performed through the radial artery.

METHODS

We enrolled 100 consecutive elective patients undergoing cardiac catheterization (diagnostic or procedural). Arterial access to the distal radial was entirely managed by nursing staff supervised by the interventional cardiologist. In this single-centre single-operator experienced study, the same nurse operator performed puncture, wiring, and sheath advancement.

RESULTS

The technical feasibility was 89% and the failure rate occurred in the first 50 cases as evidenced by the learning curve. There were no major complications and the rate of minor complications is in line with that of the radial literature. BMI (OR 1.19; 95% CI: 1.03-1.38), non-radial dominance (OR 3.5; 95% CI: 1.04-12.3) and operator's experience (OR 0.59; 95% CI: 0.35-0.99 for every 20 consecutive cases performed) were associated with DRA failures.

CONCLUSIONS

The experience is encouraging and beneficial for all staff and patients with a high percentage of technical success and few mild complications.

1005 STROKE VOLUME INDEX AND TRANSVALVULAR FLOW RATE TRAJECTORIES IN SEVERE AORTIC STENOSIS TREATED WITH TAVR

Aims

The prognostic impact of flow trajectories according to stroke volume index (SVi) and transvalvular flow rate (FR) in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve replacement (TAVR) remains poorly assessed. We evaluated and compared SVi and FR prior and after TAVR for severe AS.

Methods and results

Patients were categorized according to SVi (&lt;35 ml/m2) and FR (&lt;200 ml/sec). The association of pre- and post-TAVR SVi and FR with all-cause mortality up to 3 years was assessed with multivariable Cox regression models. Among 980 patients with pre-TAVR flow assessment, SVi was reduced in 41.3% and FR in 48.1%. Baseline flow status was not an independent mortality predictor (SVi: HR 1.39, 95%CI 0.81-2.40, FR: HR 0.86, 95%CI 0.51-1.46). Among 731 patients undergoing early (5 days, IQR 2-29) post-TAVR flow assessment, SVi recovered in 40.1% and FR in 49.0% patients with baseline low-flow. Reduced FR following TAVR was an independent predictor of mortality (HR 2.08, 95%CI 1.07-4.04) while SVi was not (HR 0.68, 95%CI 0.34-1.36). Three-year estimated mortality in patients with recovered FR was lower as compared to patients with reduced FR (13.3% vs 37.7% vs, p=0.003) and similar to patients with normal baseline FR (p=0.317).

Conclusions

Baseline flow status was not an independent predictor of mid-term mortality among all-comers with severe AS undergoing TAVR. Flow recovery early after TAVR was frequent. Post-TAVR FR, but not SVi, was independently associated with mid-term all-cause mortality. By impacting flow status, AV replacement modifies the association of flow status with outcomes.

Coronary access following ACURATE neo implantation for transcatheter aortic valve-in-valve implantation: Ex vivo analysis in patient-specific anatomies

Background

Coronary access after transcatheter aortic valve implantation (TAVI) with supra-annular self-expandable valves may be challenging or un-feasible. There is little data concerning coronary access following transcatheter aortic valve-in-valve implantation (ViV-TAVI) for degenerated surgical bioprosthesis.

Aims

To evaluate the feasibility and challenge of coronary access after ViV-TAVI with the supra-annular self-expandable ACURATE neo valve.

Materials and methods

Sixteen patients underwent ViV-TAVI with the ACURATE neo valve. Post-procedural computed tomography (CT) was used to create 3D-printed life-sized patient-specific models for bench-testing of coronary cannulation. Primary endpoint was feasibility of diagnostic angiography and PCI. Secondary endpoints included incidence of challenging cannulation for both diagnostic catheters (DC) and guiding catheters (GC). The association between challenging cannulations with aortic and transcatheter/surgical valve geometry was evaluated using pre and post-procedural CT scans.

Results

Diagnostic angiography and PCI were feasible for 97 and 95% of models respectively. All non-feasible procedures occurred in ostia that underwent prophylactic “chimney” stenting. DC cannulation was challenging in 17% of models and was associated with a narrower SoV width (30 vs. 35 mm, p < 0.01), STJ width (28 vs. 32 mm, p < 0.05) and shorter STJ height (15 vs. 17 mm, p < 0.05). GC cannulation was challenging in 23% of models and was associated with narrower STJ width (28 vs. 32 mm, p < 0.05), smaller transcatheter-to-coronary distance (5 vs. 9.2 mm, p < 0.05) and a worse coronary-commissural overlap angle (14.3° vs. 25.6^o, p < 0.01). Advanced techniques to achieve GC cannulation were required in 22/64 (34%) of cases.

Conclusion

In this exploratory bench analysis, diagnostic angiography and PCI was feasible in almost all cases following ViV-TAVI with the ACURATE neo valve. Prophylactic coronary stenting, higher implantation, narrower aortic sinus dimensions and commissural misalignment were associated with an increased challenge of coronary cannulation.

AI-SCoRE (artificial intelligence-SARS CoV2 risk evaluation): a fast, objective and fully automated platform to predict the outcome in COVID-19 patients

Purpose

To develop and validate an effective and user-friendly AI platform based on a few unbiased clinical variables integrated with advanced CT automatic analysis for COVID-19 patients’ risk stratification.

Material and Methods

In total, 1575 consecutive COVID-19 adults admitted to 16 hospitals during wave 1 (February 16-April 29, 2020), submitted to chest CT within 72 h from admission, were retrospectively enrolled.

In total, 107 variables were initially collected; 64 extracted from CT. The outcome was survival.

A rigorous AI model selection framework was adopted for models selection and automatic CT data extraction. Model performances were compared in terms of AUC. A web–mobile interface was developed using Microsoft PowerApps environment. The platform was externally validated on 213 COVID-19 adults prospectively enrolled during wave 2 (October 14-December 31, 2020).

Results

The final cohort included 1125 patients (292 non-survivors, 26%) and 24 variables. Logistic showed the best performance on the complete set of variables (AUC = 0.839 ± 0.009) as in models including a limited set of 13 and 5 variables (AUC = 0.840 ± 0.0093 and AUC = 0.834 ± 0.007). For non-inferior performance, the 5 variables model (age, sex, saturation, well-aerated lung parenchyma and cardiothoracic vascular calcium) was selected as the final model and the extraction of CT-derived parameters was fully automatized. The fully automatic model showed AUC = 0.842 (95% CI: 0.816–0.867) on wave 1 and was used to build a 0–100 scale risk score (AI-SCoRE). The predictive performance was confirmed on wave 2 (AUC 0.808; 95% CI: 0.7402–0.8766).

Conclusions

AI-SCoRE is an effective and reliable platform for automatic risk stratification of COVID-19 patients based on a few unbiased clinical data and CT automatic analysis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11547-022-01518-0.

Percutaneous vs surgical axillary access for transcatheter aortic valve implantation: the TAXI registry

BACKGROUND

Transcatheter aortic valve implantation (TAVI) is an established management strategy for severe aortic valve stenosis. Percutaneous axillary approach for TAVI holds the promise of improving safety without jeopardizing effectiveness in comparison to surgical access. We aimed at appraising the comparative effectiveness of percutaneous vs surgical axillary approaches for TAVI.

METHODS

We performed an international retrospective observational study using de-identified details on baseline, procedural, and 1-month follow-up features. Valve Academic Research Consortium (VARC)-3 criteria were applied throughout. Outcomes of interest were clinical events up to 1 month of follow-up, compared with unadjusted and propensity score-adjusted analyses.

RESULTS

A total of 432 patients were included, 189 (43.8%) receiving surgical access, and 243 (56.2%) undergoing percutaneous access. Primary hemostasis failure was more common in the percutaneous group (13.2% vs 4.2%, p<0.001), leading to more common use of covered stent implantation (13.2% vs 3.7%, p<0.001). Irrespectively, percutaneous access was associated with shorter hospital stay (-2.6 days [95% confidence interval: -5.0; -0.1], p=0.038), a lower risk of major adverse events (a composite of death, myocardial infarction, stroke, type 3 bleeding, and major access-site related complication; odds ratio=0.44 [0.21; 0.95], p=0.036), major access-site non-vascular complications (odds ratio=0.21 [0.06; 0.77], p=0.018), and brachial plexus impairment (odds ratio=0.16 [0.03; 0.76], p=0.021), and shorter hospital stay (-2.6 days [-5.0; -0.1], p=0.038).

CONCLUSIONS

Percutaneous axillary access provides similar or better results than surgical access in patients undergoing TAVI with absolute or relative contraindications to femoral access.

Spontaneous coronary artery dissection: an Italian single centre experience

AIMS

Spontaneous coronary artery dissection (SCAD) is an emerging cause of acute myocardial infarction (AMI) in young women without a typical cardiovascular risk profile. Knowledge on SCAD is based on observational studies and is still scarce. The aim of this monocentric observational study was to evaluate the predisposing factors, clinical features and prognosis of SCAD patients.

METHODS

Between 2013 and 2020, 58 patients with angiographic diagnosis of SCAD were identified in our centre with an overall prevalence of 0.9% among patients admitted for AMI (58 of 6414 patients).

RESULTS

The mean age was 54 ± 11 years and the majority were women (n = 50, 86%) with one or fewer cardiovascular risk factors (n = 35, 60%). The prevalence of Fibromuscolar Dysplasia (FMD) was 39% (7 of 18 screened patients). The rate of major adverse cardiovascular and cerebrovascular events (MACCEs) was used to assess the prognosis. Out-of-hospital cardiac arrest because of ventricular fibrillation was observed in four (7%) patients. The majority of patients (n = 51, 88%) were treated conservatively without revascularization. The in-hospital and 30-day clinical course was uneventful in most patients (n = 54, 93%) with two cardiac deaths. During a median follow-up of 12 months, there were no further deaths. The global rate of SCAD recurrence was significant (n = 8, 14%) but predictors have not been identified.

CONCLUSION

Although overall survival seems good, SCAD is a potentially malignant, not rare disease, which can present with sudden cardiac death and not uncommon recurrence. Prognostic stratification and optimal management of SCAD patients remain to be defined.

[Robotic percutaneous coronary intervention: current evidence, practical aspects and future perspectives]

Robotic percutaneous coronary intervention (R-PCI) is an emerging technology designed to improve operator safety and procedural precision. The interventional cardiologist is able to manipulate guidewires, catheters and devices from a specific cockpit. A number of studies evaluating R-PCI have shown high procedural success rates with low complications. R-PCI advantages include the possibility to perform an accurate stent positioning, to reduce the operator radiation exposure and orthopedic injuries. However, there is a limited experience regarding R-PCI in complex anatomies, that may still require manual assistance. Moreover, the technique is limited by current incompatibility with specific materials, the lack of tactile feedback and the possibility to robotically manage only one wire/device at the same time. Globally, R-PCI is a novel approach with future interesting implications, but further investigations are necessary to overcome current limitations.

Acute Right Ventricular Reshaping After TriClip in Ebstein's-Like Anomaly Assessed by Multimodality Imaging

The efficacy of transcatheter edge-to-edge tricuspid valve repair (TTVR) has been recently demonstrated not only for the reduction of tricuspid regurgitation (TR) but also in terms of right ventricular remodeling. We report the case of a 78-year-old female patient with a history of atrial fibrillation and severe isolated TR in New York Heart Association functional classification III despite optimal medical therapy. These case images help to illustrate immediate and considerable right ventricular reshaping due to successful TTVR with a sustained result at 6 months in isolated primary TR.

The role of cardiovascular calcifications in COVID-19

Background

Coronary, thoracic aorta and aortic valve calcium can be measured from a non-gated chest computer tomography (CT) and are validated predictors of cardiovascular events and all-cause mortality. However, their prognostic role in acute systemic inflammatory diseases, such as COVID-19, has not been investigated.

Purpose

The principal aim was to evaluate the association of coronary artery calcium (CAC) and total thoracic calcium on in-hospital mortality in COVID-19 patients. Then, to evaluate the prognostic impact of clinical and subclinical coronary artery disease (CAD), as assessed by CAC.

Methods

1093 consecutive patients from 16 Italian hospitals with a positive swab for COVID-19 and an admission chest CT for pneumonia severity assessment were included in the SCORE COVID-19 registry (calcium score for COVID-19 Risk Evaluation). At CT, coronary, aortic valve and thoracic aorta calcium were qualitatively and quantitatively evaluated separately and combined together (total thoracic calcium) by a central Core-lab blinded to patients' outcomes. A specific sub analysis on CAC was performed stratifying the patients in three groups: (a) “clinical CAD” (prior revascularization history), (b) “subclinical CAD” (CAC &gt;0), (c) “No CAD” (CAC=0). In-hospital mortality was the primary endpoint, while a composite of myocardial infarction and cerebrovascular accident (MI/CVA) was the secondary one.

Results

Non-survivors compared to survivors had higher coronary artery [(487.7±565.3 vs 207.7±406.8, p&lt;0.001)], aortic valve [(322.4±390.9 vs 98.2±250.7 mm2, p&lt;0.001)] and thoracic aorta [(3786.7±4225.5 vs 1487.6±2973.1 mm2, p&lt;0.001)] calcium values. Coronary artery calcium (HR 1.308; 95% CI, 1.046 - 1.637, p=0.019) and total thoracic calcium (HR 1.975; 95% CI, 1.200 - 3.251, p=0.007) resulted to be independent predictors of in-hospital mortality. In the sub - analysis increasing rates of in-hospital mortality (11.3% vs. 27.3% vs. 39.8%, p&lt;0.001) and MI/CVA events (2.3% vs. 3.8% vs. 11.9%, p&lt;0.001) were observed from the No CAD to the clinical CAD groups. Among patients with subclinical CAD, increasing CAC burden was associated with higher rates of in-hospital mortality (20.5% vs. 27.9% vs. 38.7% for patients with CAC score thresholds ≤100, 101–400 and &gt;400, respectively, p&lt;0.001)

Conclusion

Coronary, aortic valve and thoracic aortic calcium assessment on admission non-gated CT permits to stratify the COVID-19 patients in-hospital mortality risk. Cardiovascular calcifications may represent a bystander of an impaired vascular reserve, both microvascular and endothelial, but also a sign of vascular senescence. Therefore, it can be considered an index of biological frailty, likely more accurate than age and other risk factors.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

A Case of Catheter-Based Tricuspid Valve Repair Reversing the Previous Success of Transcatheter Mitral Valve Repair: A New Scenario Requires New Answers

Concomitant severe mitral-tricuspid regurgitation is observed in up to 30% of patients with reduced left ventricular ejection fraction. In symptomatic subjects at high surgical risk, transcatheter treatment is a viable option in the presence of suitable anatomy. We present a case of mitral regurgitation worsening after TriClip (Abbott, Abbott Park, IL) implantation in a patient with a previous successful MitraClip (Abbott) intervention. The correction of tricuspid regurgitation by catheter repair improves overall hemodynamics, but it can sometimes paradoxically worsen mitral regurgitation, as herein displayed. Clinical care is needed to detect tricuspid regurgitation repair-induced worsening of mitral regurgitation and ensure optimal management.

[Transcatheter approach of concomitant mitral and tricuspid regurgitation]

Severe mitral regurgitation represents the second most common indication for valve surgery in Europe. In the last decade, transcatheter mitral valve repair has become an established effective and safe treatment option for patients at high or prohibitive operative risk. A relevant proportion of these patients develop significant tricuspid regurgitation. Once considered a benign and reversible finding, nowadays increasing attention is being paid to the coexistence of this valvular disease, as a growing body of evidence points towards its negative prognostic role. Over the last few years, transcatheter repair has been performed successfully also for the treatment of significant tricuspid regurgitation in patients at high surgical risk. Therefore, combined transcatheter repair is emerging as a treatment strategy for high surgical risk patients with both severe mitral and tricuspid regurgitation. In this review, we provide a comprehensive summary of the epidemiology, pathophysiology, and prognostic role of the coexistence of severe mitral and tricuspid regurgitation. We then discuss the evidence in favor of combined surgical treatment and the emerging data supporting combined transcatheter treatment, with attention to available treatment technologies. The paper is further enriched with three practical case reports and with the suggestion of a decision-making algorithm for the management of this complex subset of patients.

The hidden interplay between sex and COVID-19 mortality: the role of cardiovascular calcification

Recent clinical and demographical studies on COVID-19 patients have demonstrated that men experience worse outcomes than women. However, in most cases, the data were not stratified according to gender, limiting the understanding of the real impact of gender on outcomes. This study aimed to evaluate the disaggregated in-hospital outcomes and explore the possible interactions between gender and cardiovascular calcifications. Data was derived from the sCORE-COVID-19 registry, an Italian multicentre registry that enrolled COVID-19 patients who had undergone a chest computer tomography scan on admission. A total of 1683 hospitalized patients (mean age 67±14 years) were included. Men had a higher prevalence of cardiovascular comorbidities, a higher pneumonia extension, more coronary calcifications (63% vs.50.9%, p<0.001), and a higher coronary calcium score (391±847 vs. 171±479 mm3, p<0.001). Men experienced a significantly higher mortality rate (24.4% vs. 17%, p=0.001), but the death event tended to occur earlier in women (15±7 vs. 8±7 days, p= 0.07). Non-survivors had a higher coronary, thoracic aorta, and aortic valve calcium score. Female sex, a known independent predictor of a favorable outcome in SARS-CoV2 infection, was not protective in women with a coronary calcification volume greater than 100 mm3. There were significant differences in cardiovascular comorbidities and vascular calcifications between men and women with SARS-CoV2 pneumonia. The differences in outcomes can be at least partially explained by the different cardiovascular profiles. However, women with poor outcomes had the same coronary calcific burden as men. The presumed favorable female sex bias in COVID-19 must therefore be reviewed in the context of comorbidities, especially cardiovascular ones.

Coronary and total thoracic calcium scores predict mortality and provides pathophysiologic insights in COVID-19 patients

BACKGROUND

Coronavirus disease 2019 (COVID-19) has spread worldwide determining dramatic impacts on healthcare systems. Early identification of high-risk parameters is required in order to provide the best therapeutic approach. Coronary, thoracic aorta and aortic valve calcium can be measured from a non-gated chest computer tomography (CT) and are validated predictors of cardiovascular events and all-cause mortality. However, their prognostic role in acute systemic inflammatory diseases, such as COVID-19, has not been investigated.

OBJECTIVES

The aim was to evaluate the association of coronary artery calcium and total thoracic calcium on in-hospital mortality in COVID-19 patients.

METHODS

1093 consecutive patients from 16 Italian hospitals with a positive swab for COVID-19 and an admission chest CT for pneumonia severity assessment were included. At CT, coronary, aortic valve and thoracic aorta calcium were qualitatively and quantitatively evaluated separately and combined together (total thoracic calcium) by a central Core-lab blinded to patients' outcomes.

RESULTS

Non-survivors compared to survivors had higher coronary artery [Agatston (467.76 ​± ​570.92 vs 206.80 ​± ​424.13 ​mm2, p ​< ​0.001); Volume (487.79 ​± ​565.34 vs 207.77 ​± ​406.81, p ​< ​0.001)], aortic valve [Volume (322.45 ​± ​390.90 vs 98.27 ​± ​250.74 mm2, p ​< ​0.001; Agatston 337.38 ​± ​414.97 vs 111.70 ​± ​282.15, p ​< ​0.001)] and thoracic aorta [Volume (3786.71 ​± ​4225.57 vs 1487.63 ​± ​2973.19 mm2, p ​< ​0.001); Agatston (4688.82 ​± ​5363.72 vs 1834.90 ​± ​3761.25, p ​< ​0.001)] calcium values. Coronary artery calcium (HR 1.308; 95% CI, 1.046-1.637, p ​= ​0.019) and total thoracic calcium (HR 1.975; 95% CI, 1.200-3.251, p ​= ​0.007) resulted to be independent predictors of in-hospital mortality.

CONCLUSION

Coronary, aortic valve and thoracic aortic calcium assessment on admission non-gated CT permits to stratify the COVID-19 patients in-hospital mortality risk.

Impact of clinical and subclinical coronary artery disease as assessed by coronary artery calcium in COVID-19

BACKGROUND AND AIMS

The potential impact of coronary atherosclerosis, as detected by coronary artery calcium, on clinical outcomes in COVID-19 patients remains unsettled. We aimed to evaluate the prognostic impact of clinical and subclinical coronary artery disease (CAD), as assessed by coronary artery calcium score (CAC), in a large, unselected population of hospitalized COVID-19 patients undergoing non-gated chest computed tomography (CT) for clinical practice.

METHODS

SARS-CoV 2 positive patients from the multicenter (16 Italian hospitals), retrospective observational SCORE COVID-19 (calcium score for COVID-19 Risk Evaluation) registry were stratified in three groups: (a) "clinical CAD" (prior revascularization history), (b) "subclinical CAD" (CAC >0), (c) "No CAD" (CAC = 0). Primary endpoint was in-hospital mortality and the secondary endpoint was a composite of myocardial infarction and cerebrovascular accident (MI/CVA).

RESULTS

Amongst 1625 patients (male 67.2%, median age 69 [interquartile range 58-77] years), 31%, 57.8% and 11.1% had no, subclinical and clinical CAD, respectively. Increasing rates of in-hospital mortality (11.3% vs. 27.3% vs. 39.8%, p < 0.001) and MI/CVA events (2.3% vs. 3.8% vs. 11.9%, p < 0.001) were observed for patients with no CAD vs. subclinical CAD vs clinical CAD, respectively. The association with in-hospital mortality was independent of in-study outcome predictors (age, peripheral artery disease, active cancer, hemoglobin, C-reactive protein, LDH, aerated lung volume): subclinical CAD vs. No CAD: adjusted hazard ratio (adj-HR) 2.86 (95% confidence interval [CI] 1.14-7.17, p=0.025); clinical CAD vs. No CAD: adj-HR 3.74 (95% CI 1.21-11.60, p=0.022). Among patients with subclinical CAD, increasing CAC burden was associated with higher rates of in-hospital mortality (20.5% vs. 27.9% vs. 38.7% for patients with CAC score thresholds≤100, 101-400 and > 400, respectively, p < 0.001). The adj-HR per 50 points increase in CAC score 1.007 (95%CI 1.001-1.013, p=0.016). Cardiovascular risk factors were not independent predictors of in-hospital mortality when CAD presence and extent were taken into account.

CONCLUSIONS

The presence and extent of CAD are associated with in-hospital mortality and MI/CVA among hospitalized patients with COVID-19 disease and they appear to be a better prognostic gauge as compared to a clinical cardiovascular risk assessment.

Chest CT-derived pulmonary artery enlargement at the admission predicts overall survival in COVID-19 patients: insight from 1461 consecutive patients in Italy

OBJECTIVES

Enlarged main pulmonary artery diameter (MPAD) resulted to be associated with pulmonary hypertension and mortality in a non-COVID-19 setting. The aim was to investigate and validate the association between MPAD enlargement and overall survival in COVID-19 patients.

METHODS

This is a cohort study on 1469 consecutive COVID-19 patients submitted to chest CT within 72 h from admission in seven tertiary level hospitals in Northern Italy, between March 1 and April 20, 2020. Derivation cohort (n = 761) included patients from the first three participating hospitals; validation cohort (n = 633) included patients from the remaining hospitals. CT images were centrally analyzed in a core-lab blinded to clinical data. The prognostic value of MPAD on overall survival was evaluated at adjusted and multivariable Cox's regression analysis on the derivation cohort. The final multivariable model was tested on the validation cohort.

RESULTS

In the derivation cohort, the median age was 69 (IQR, 58-77) years and 537 (70.6%) were males. In the validation cohort, the median age was 69 (IQR, 59-77) years with 421 (66.5%) males. Enlarged MPAD (≥ 31 mm) was a predictor of mortality at adjusted (hazard ratio, HR [95%CI]: 1.741 [1.253-2.418], p < 0.001) and multivariable regression analysis (HR [95%CI]: 1.592 [1.154-2.196], p = 0.005), together with male gender, old age, high creatinine, low well-aerated lung volume, and high pneumonia extension (c-index [95%CI] = 0.826 [0.796-0.851]). Model discrimination was confirmed on the validation cohort (c-index [95%CI] = 0.789 [0.758-0.823]), also using CT measurements from a second reader (c-index [95%CI] = 0.790 [0.753;0.825]).

CONCLUSION

Enlarged MPAD (≥ 31 mm) at admitting chest CT is an independent predictor of mortality in COVID-19.

KEY POINTS

• Enlargement of main pulmonary artery diameter at chest CT performed within 72 h from the admission was associated with a higher rate of in-hospital mortality in COVID-19 patients. • Enlargement of main pulmonary artery diameter (≥ 31 mm) was an independent predictor of death in COVID-19 patients at adjusted and multivariable regression analysis. • The combined evaluation of clinical findings, lung CT features, and main pulmonary artery diameter may be useful for risk stratification in COVID-19 patients.

Rupture of a Vulnerable Plaque in a Hazy Angiographic Culprit Lesion During Acute Coronary Syndrome

In the presence of an equivocal culprit lesion in the context of an acute coronary syndrome, the optical coherence tomography (OCT) scan defines the severity and composition of the plaque, elucidating (as in this pathognomonic case) the mechanism related to plaque rupture. Furthermore, OCT analysis allowed stent implantation with adequate sizing and length, and subsequent final optimization of the result. In the presence of non-unequivocal lesions, in the context of acute coronary syndrome, the use of OCT imaging defined the etiology and mechanism of plaque instability, reducing cardiovascular events. In this clinical scenario, it is necessary to have a low threshold for the use of intracoronary imaging methods. In a challenging scenario, resorting to intracoronary imaging when possible can reduce the risk of procedural and postprocedural complication.

Iatrogenic aorta-coronary dissection: Case report and systematic review

OBJECTIVES AND BACKGROUND

Iatrogenic aorto-coronary dissection (ICD) is one of the most feared complications of interventional cardiology. Although rare, it is characterized by anterograde coronary ischemia and a concomitant aortic dissection, with potentially fatal consequences.

METHODS

We present an example case of IACD and an accurate case-series review of the literature including 125 published cases.

RESULTS

There were no significant predisposing factors and the IACD occurred equally in elective and urgent procedures. A significant number of IACDs were associated with CTO procedures. The factors associated with a worse outcome were hemodynamic instability, the presence of anterograde ischemia, and the extent of dissection according to the Dunning classification. Bail-out stenting was the most used strategy and its failure was associated with mortality.

CONCLUSION

The main features of IACD are anterograde ischemia, retrograde dissection, and hemodynamic instability, each of them should be addressed with no time delay, possibly with bailout stenting, the most employed exit-strategy. According to our proposed algorithm, a shock team approach is required to coordinate the interdisciplinary skills and enabled patients to receive the best treatment.

Is pleural effusion in COVID-19 interstitial pneumonia related to in-hospital mortality?

The recent severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) pandemic has highlighted the importance of pulmonary computed tomography (CT) for diagnosis and prognostic stratification of this new viral pneumonia. 1370 lung CT scans (performed at the time of admission) of consecutive patients hospitalized for SARS-CoV-2 in Northern Italy during the first epidemic wave were analyzed by a radiological CoreLab. The presence of pleural effusion on pulmonary CT scan was present in 188 patients (13.3% of the population) and identified a population with more comorbidities. Patients with pleural effusion had more cardio-respiratory complications with higher mortality. Pleural effusion was an independent predictor of death on multivariate analysis with an HR of 1.4 (95% confidence interval 1-1.9). Pulmonary CT pleural effusion was an independent predictor of mortality.

Computed tomography analysis of coronary ostia location following valve-in-valve transcatheter aortic valve replacement with the ACURATE neo valve: Implications for coronary access

BACKGROUND

Valve-in-valve transcatheter aortic valve replacement (ViV-TAVR) is an emerging alternative to re-do surgery. However, the challenge of coronary access (CA) following ViV-TAVR is a potential limitation as TAVR expands to younger lower-risk populations.

OBJECTIVES

Using post-implantation computed tomography (CT) scans to evaluate the geometrical relationship between coronary ostia and valve frame in patients undergoing ViV-TAVR with the ACURATE neo valve.

METHODS

Post-implant CT scans of 18 out of 20 consecutive patients treated with the ACURATE neo valve were analyzed. Coronary ostia location in relation to the highest plane (HP) (highest point of the ACURATE neo or surgical valve) was determined. Ostia located below the highest plan were further subclassified according to the gap available between the transcatheter heart valve frame and ostium (transcatheter-to-coronary [TTC] distance). The impact implantation depth has on these geometrical relationships was evaluated.

RESULTS

A total of 21 out of 36 coronary ostia (58%) were located below the level of the HP with the left coronary artery (36%) more likely to be affected than the right (22%). Further sub-classification of these ostia revealed a large (>6 mm), moderate (4-6 mm), and small (<4 mm) TTC distance in 57% (12/21), 38% (8/21), and in 6% (1/18) of cases, respectively. At an implantation depth <4 mm compared to >4 mm, all ostia were located below the HP with no difference in post-procedural mean gradients (14.5 mmHg ± 4.7 vs. 12.6 mmHg ± 5.8; p = .5, 95%CI 3.8-7.5).

CONCLUSIONS

CA following ACURATE neo implantation for ViV-TAVR could potentially be challenging in a significant proportion of patients and specific consideration should be given to the implantation depth.

Bioresorbable Vascular Scaffold With Optimized Implantation Technique: Long-Term Outcomes From a Single-Center Experience

BACKGROUND

Previous randomized controlled trials demonstrated a higher rate of stent thrombosis with bioresorbable vascular scaffold (BVS) implantation as compared with second-generation drug-eluting stent in selected patients/lesions. However, long-term outcomes of BVS implantations that utilize an optimized technique (OIT) in unselected patients/lesions are lacking. The aim of this study was to assess the real-world, long-term clinical outcomes of BVS (Absorb; Abbott Vascular) with OIT.

METHODS AND RESULTS

In a cohort of 156 patients, a total of 347 BVS devices (435 lesions) were implanted, with intravascular ultrasound (IVUS) guidance utilized in 303 (87.3%) of the scaffolds. The primary efficacy endpoint was target-lesion revascularization (TLR) and the primary safety endpoint was scaffold thrombosis. Despite performing routine high-pressure postdilation, postintervention IVUS detected BVS underexpansion/malapposition in 53 scaffolds (28.7%), requiring further postdilation. At a median follow-up of 60 months (interquartile range, 45-73 months), TLR and scaffold thrombosis occurred in 16 patients (10.3%) and 1 patient (0.6%), respectively. At univariable analysis, IVUS-guided scaffold implantation was associated with lower TLR (odds ratio, 0.24; 95% confidence interval, 0.09-0.62; P<.01).

CONCLUSION

The use of first-generation BVS with OIT in real-world patients/lesions was associated with acceptable long-term outcomes.

Incidence and characterization of acute pulmonary embolism in patients with SARS-CoV-2 pneumonia: A multicenter Italian experience

BACKGROUND AND AIMS

Several studies reported a high incidence of pulmonary embolism (PE) among patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection, but detailed data about clinical characteristics, risk factors of these patients and prognostic role of PE are still lacking. We aim to evaluate the occurrence of pulmonary embolism among patients with SARS-CoV-2 infection, and to describe their risk factors, clinical characteristics, and in-hospital clinical outcomes.

METHODS

This is a multicenter Italian study including 333 consecutive SARS-CoV-2 patients admitted to seven hospitals from February 22 to May 15, 2020. All the patients underwent computed tomography pulmonary angiography (CTPA) for PE detection. In particular, CTPA was performed in case of inadequate response to high-flow oxygen therapy (Fi02≥0.4 to maintain Sp02≥92%), elevated D-dimer (>0.5μg/mL), or echocardiographic signs of right ventricular dysfunction. Clinical, laboratory and radiological data were also analyzed.

RESULTS

Among 333 patients with laboratory confirmed SARS-CoV-2 pneumonia and undergoing CTPA, PE was detected in 109 (33%) cases. At CTPA, subsegmental, segmental, lobar and central thrombi were detected in 31 (29%), 50 (46%), 20 (18%) and 8 (7%) cases, respectively. In-hospital death occurred in 29 (27%) patients in the PE-group and in 47 (21%) patients in the non-PE group (p = 0.25). Patients in PE-group had a low rate of traditional risk factors and deep vein thrombosis was detected in 29% of patients undergoing compression ultrasonography. In 71% of cases with documented PE, the thrombotic lesions were located in the correspondence of parenchymal consolidation areas.

CONCLUSIONS

Despite a low rate of risk factors for venous thromboembolism, PE is present in about 1 out 3 patients with SARS-CoV-2 pneumonia undergoing CTPA for inadequate response to oxygen therapy, elevated D-dimer level, or echocardiographic signs of right ventricular dysfunction. In most of the cases, the thromboses were located distally in the pulmonary tree and were mainly confined within pneumonia areas.

Effect of compost application on the dynamics of carbon in a nectarine orchard ecosystem

The aim of the present study was to compare the quantity and the type of carbon (C) stored during the 14-year lifetime of a commercial nectarine orchard ecosystem fertilized with mineral or organic fertilizers. The study was carried out in the Po valley, Italy, in a nectarine orchard of the variety Stark RedGold, grafted on GF677 hybrid peach × almond. Since orchard planting in August 2001, the following treatments were applied in a randomized complete block design with four replicates per block and compared: 1. unfertilized control; 2. mineral fertilization (including P and K at planting and N applied as NO₃NH₄ yearly at the rate of 70-130 kg ha^-1); 3. compost application at a rate of 5 Mg DW ha^-1 yr^-1; 4. compost application at a rate of 10 Mg DW ha^-1 yr^-1. Compost was obtained from domestic organic wastes mixed with pruning material from urban ornamental trees and garden management after a 3-month stabilization period. Application of compost at the highest rate increased C in the soil; the amount of C sequestered was approximately 60% from amendment source and 40% from the net primary production of trees and grasses with a net increase of C compared to mineral fertilization. Compost application was found to be a win-win strategy to increase C storage in soil and, at the same time, to promote plant growth and yield to levels similar to those obtained with mineral fertilization. The rate of C application is crucial, indicated by the fact that compost supply at the rate of 10 Mg ha^-1 yr^-1 was the only fertilization strategy of the ones tested that resulted in higher C sequestration. This shows that compost amendment may stimulate an increase in the net primary production of plants.

Organic fertilization leads to increased peach root production and lifespan

We evaluated the effects of mineral and organic fertilizers on peach root dynamics in the growing season from 2003 to 2006 in a nectarine (Prunus persica L.) orchard, planted in 2001 and located in the Po valley, northeastern Italy. Very few studies have conducted long-term investigations of root dynamics of fruit crops. Our main objective was to determine whether organic fertilizers affect root dynamics differently than mineral fertilizers. The experiment was a completely randomized block design with four replicates of three treatments: unfertilized, mineral fertilized and composted with municipal waste. Mineral fertilizers included P (100 kg ha(-1) year(-1)) and K (200 kg ha(-1) year(-1)) applied only at planting and N (70-130 kg ha(-1) year(-1)) split into two applications, one at 40 days after full bloom (60%) and the other in September (40%) each year. The compost fertilization represented a yearly rate of 10 metric tons (t) dry weight ha(-1), which approximates (in kg ha(-1) year(-1)) 240 N, 100 P and 200 K, split similarly to that described for the mineral fertilization of N. Both root growth and survival were evaluated at 20-day intervals during the growing season by the minirhizotron technique. Compost increased the production of new roots compared with the other treatments (P < 0.01). Roots were mainly produced at a depth of 41-80 cm and from March to May and in late summer. An analysis of covariance indicated no significant effect of soil nitrate on root production (P = 0.47). The root lifespan was longer in compost-treated trees than in mineral-fertilized or unfertilized trees (P < 0.01) and it was strongly affected by time of birth; roots born later in the summer lived longer than those born in the spring. Across years and treatments, the average root lifespan was positively correlated with soil nitrate (r = 0.60; P < 0.001). Variation in root lifespan with method of fertilization could be accounted for by variation in soil nitrate concentration as indicated by no effect of fertilizer treatment on root lifespan when soil nitrate was included as a covariate. These results reveal how shifting from mineral to organic fertilizers may shift both soil properties and nutrient availability, leading to changes in both root production and lifespan.

Design of surface properties of PET films: Effect of fluorinated block copolymers

This paper demonstrates that the addition of fluorinated block copolymers to PET solutions can be used to prepare PET films with controlled surface morphology, porosity and chemical composition, by exploiting the phenomenon known as breath figures (BF) formation during a spin-coating procedure. Surface features, such as number, depth and diameter of pores and chemical composition, can be tuned by varying the experimental conditions: relative humidity, solution composition and amount of the fluorinated block copolymer added to the PET solutions (in the range of 0.5-10 wt% with respect to PET). BF patterns are more evident at relatively high concentrations of PET (3 wt%) and content of fluorinated block copolymer (10 wt% with respect to PET) in the solution. According to the obtained results, the fluorinated block copolymer seems to play a role in different steps of the mechanism of BF formation. XPS measurements showed a surface composition much richer in fluorinated segments than expected from bulk composition. The combined surface roughness and surface segregation of fluorinated segments have only a limited effect on the macroscopic wettability of the surfaces.

Differentiating embryonic stem–derived neural stem cells show a maturation-dependent pattern of voltage-gated sodium current expression and graded action potentials

A population of mouse embryonic stem (ES)-derived neural stem cells (named NS cells) that exhibits traits reminiscent of radial glia-like cell population and that can be homogeneously expanded in monolayer while remaining stable and highly neurogenic over multiple passages has been recently discovered. This novel population has provided a unique in vitro system in which to investigate physiological events occurring as stem cells lose multipotency and terminally differentiate. Here we analysed the timing, quality and quantity of the appearance of the excitability properties of differentiating NS cells which have been long-term expanded in vitro. To this end, we studied the biophysical properties of voltage-dependent Na(+) currents as an electrophysiological readout for neuronal maturation stages of differentiating NS cells toward the generation of fully functional neurons, since the expression of neuronal voltage-gated Na(+) channels is an essential hallmark of neuronal differentiation and crucial for signal transmission in the nervous system. Using the whole cell and single-channel cell-attached variations of the patch-clamp technique we found that the Na(+) currents in NS cells showed substantial electrophysiological changes during in vitro neuronal differentiation, consisting mainly in an increase of Na(+) current density and in a shift of the steady-state activation and inactivation curves toward more negative and more positive potentials respectively. The changes in the Na(+) channel system were closely related with the ability of differentiating NS cells to generate action potentials, and could therefore be exploited as an appropriate electrophysiological marker of ES-derived NS cells undergoing functional neuronal maturation.

A fast transient outward current in layer II/III neurons of rat perirhinal cortex

The perirhinal cortex (PRC) is a supra-modal cortical area that collects and integrates information originating from uni- and multi-modal neocortical regions, transmits it to the hippocampus, and receives a feedback from the hippocampus itself. The elucidation of the mechanisms that underlie the specific excitable properties of the different PRC neuronal types appears as an important step toward the understanding of the integrative functions of PRC. In this study, we investigated the biophysical properties of the transient, I (A)-type K(+) current recorded in pyramidal neurons acutely dissociated from layers II/III of PRC of the rat (P8-P16). The current activated at about -50 mV and showed a fast monoexponential decay (tau(h) >> 14 ms at -30 to +10 mV). I (A) recovery from inactivation also had a monoexponential time course. No significant differences in the biophysical properties or current density of I (A) were found in pyramidal neurons from rats of different ages. Application of 4-AP (1-5 mM) reversibly and selectively blocked I (A), and in current clamp conditions it increased spike duration and shortened the delay of the first spike during repetitive firing evoked by sustained depolarizing current injection. These properties are similar to those of the I (A) found in thalamic neurons and other cortical pyramidal neurons. Our results suggest that I (A) contributes to spike repolarization and to regulate both spike onset timing and firing frequency in PRC neurons.

Antibacterial Activity of Plastics Coated with Silver-Doped Organic−Inorganic Hybrid Coatings Prepared by Sol−Gel Processes

Silver-doped organic-inorganic hybrid coatings were prepared starting from tetraethoxysilane- and triethoxysilane-terminated poly(ethylene glycol)-block-polyethylene by the sol-gel process. They were applied as a thin layer (0.6-1.1 microm) to polyethylene (PE) and poly(vinyl chloride) (PVC) films and the antibacterial activity of the coated films was tested against Gram-negative (Escherichia coli ATCC 25922) and Gram-positive (Staphylococcus aureus ATCC 6538) bacteria. The effect of several factors (such as organic-inorganic ratio, type of catalyst, time of post-curing, silver ion concentration, etc.) was investigated. Measurements at different contact times showed a rapid decrease of the viable count for both tested strains. The highest antibacterial activity [more than 6 log reduction within 6 h starting from 106 colony-forming units (cfu) mL-1] was obtained for samples with an organic-inorganic weight ratio of 80:20 and 5 wt % silver salt with respect to the coating. For the coatings prepared by an acid-catalyzed process, a high level of permanence of the antibacterial activity of the coated films was demonstrated by repeatedly washing the samples in warm water or by immersion in physiological saline solution at 37 degrees C for 3 days. The release of silver ions per square meter of coating is very similar to that previously observed for polyamides filled with metallic silver nanoparticles; however, when compared on the basis of Ag content, the concentration of silver ions released from the coating is much higher than that released from 1 mm thick specimens of polyamide (PA) filled with silver nanoparticles. Transparency and good adhesion of the coating to PE and PVC plastic substrates without any previous surface treatment are further interesting features.