Renin-angiotensin system inhibitors reduce cardiovascular mortality in hypertensive patients with severe aortic stenosis undergoing transcatheter aortic valve implantation: insights from the EffecTAVI registry

Objectives

Arterial hypertension is associated with the triggering of the renin-angiotensin system, leading to left ventricle fibrosis and worse cardiovascular outcomes. In this study, patients with comorbid arterial hypertension and severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) were selected from the EffecTAVI registry to evaluate the impact of angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) on cardiovascular mortality.

Methods

We enrolled 327 patients undergoing TAVI from the EffecTAVI registry. Using Kaplan-Meier event rates and study-stratified multivariable Cox proportional hazards regression models, we evaluated 2-year clinical outcomes according to the ACEI/ARB therapy status at enrollment.

Results

Among the included patients, 222 (67.9%) were on ACEIs/ARBs at baseline, whereas 105 (32.1%) were not. Treatment with ACEIs/ARBs was significantly associated with a 2-year decrease in the rate of cardiovascular mortality (HR = 0.44, 95% CI: 0.23-0.81, p = 0.009). This association remained stable after both multivariable adjustment and propensity score matching.

Conclusion

In a cohort of hypertensive patients with severe AS who were selected from the EffecTAVI registry, ACEI/ARB treatment at baseline was found to be independently associated with a lower risk of 2-year cardiovascular mortality, suggesting a potential benefit of this treatment. More trials are needed to validate this finding and to understand the full benefit of this treatment.

Echocardiographic Evaluation of Aortic Stenosis: A Comprehensive Review

Echocardiography represents the most important diagnostic tool in the evaluation of aortic stenosis. The echocardiographic assessment of its severity should always be performed through a standardized and stepwise approach in order to achieve a comprehensive evaluation. The latest technical innovations in the field of echocardiography have improved diagnostic accuracy, guaranteeing a better and more detailed evaluation of aortic valve anatomy. An early diagnosis is of utmost importance since it shortens treatment delays and improves patient outcomes. Echocardiography plays a key role also in the evaluation of all the structural changes related to aortic stenosis. Detailed evaluation of subtle and subclinical changes in left ventricle function has a prognostic significance: scientific efforts have been addressed to identify the most accurate global longitudinal strain cut-off value able to predict adverse outcomes. Moreover, in recent years the role of artificial intelligence is increasingly emerging as a promising tool able to assist cardiologists in aortic stenosis screening and diagnosis, especially by reducing the rate of aortic stenosis misdiagnosis.

Beyond Aortic Stenosis: Addressing the Challenges of Multivalvular Disease Assessment

Aortic stenosis (AS) can often coexist with other valvular diseases or be combined with aortic regurgitation (AR), leading to unique pathophysiological conditions. The combination of affected valves can vary widely, resulting in a lack of standardized diagnostic or therapeutic approaches. Echocardiography is crucial in assessing patients with valvular heart disease (VHD), but careful consideration of the hemodynamic interactions between combined valvular defects is necessary. This is important as it may affect the reliability of commonly used echocardiographic parameters, making the diagnosis challenging. Therefore, a multimodality imaging approach, including computed tomography or cardiac magnetic resonance, is often not just beneficial but crucial. It represents the future of diagnostics in this intricate field due to its unprecedented capacity to quantify and comprehend valvular pathology. The absence of definitive data and guidelines for the therapeutic management of AS in the context of multiple valve lesions makes this condition particularly challenging. As a result, an individualized, case-by-case approach is necessary, guided primarily by the recommendations for the predominant valve lesion. This review aims to summarize the pathophysiology of AS in the context of multiple and mixed valve disease, with a focus on the hemodynamic implications, diagnostic challenges, and therapeutic options.

Effects on Right Ventricular Function One Year after COVID-19-Related Pulmonary Embolism

The aim of this study was to investigate the presence of subclinical cardiac dysfunction in recovered coronavirus disease 2019 (COVID-19) patients, who were stratified according to a previous diagnosis of pulmonary embolism (PE) as a complication of COVID-19 pneumonia. Out of 68 patients with SARS-CoV-2 pneumonia followed up for one year, 44 patients (mean age 58.4 ± 13.3, 70% males) without known cardiopulmonary disease were divided in two groups (PE+ and PE-, each comprising 22 patients) and underwent clinical and transthoracic echocardiographic examination, including right-ventricle global longitudinal strain (RV-GLS), and RV free wall longitudinal strain (RV-FWLS). While no significant differences were found in the left- or right-heart chambers' dimensions between the two study groups, the PE+ patients showed a significant reduction in RV-GLS (-16.4 ± 2.9 vs. -21.6 ± 4.3%, p < 0.001) and RV-FWLS (-18.9 ± 4 vs. -24.6 ± 5.12%, p < 0.001) values compared to the PE- patients. According to the ROC-curve analysis, RV-FWLS < 21% was the best cut-off with which to predict PE diagnosis in patients after SARS-CoV-2 pneumonia (sensitivity 74%, specificity 89%, area under the curve = 0.819, p < 0.001). According to the multivariate logistic regression model, RV-FWLS < 21% was independently associated with PE (HR 34.96, 95% CI:3.24-377.09, p = 0.003) and obesity (HR 10.34, 95% CI:1.05-101.68, p = 0.045). In conclusion, in recovered COVID-19 patients with a history of PE+, there is a persistence of subclinical RV dysfunction one year after the acute phase of the disease, detectable by a significant impairment in RV-GLS and RV-FWLS. A reduction in RV-FWLS of lower than 21% is independently associated with COVID-related PE.

Hemodynamic Performance of Transcatheter Aortic Valves: A Comprehensive Review

Transcatheter aortic valve implantation (TAVI) is a widely adopted treatment option for patients with severe aortic stenosis. Its popularity has grown significantly in recent years due to advancements in technology and imaging. As TAVI use is increasingly expanded to younger patients, the need for long-term assessment and durability becomes paramount. This review aims to provide an overview of the diagnostic tools to evaluate the hemodynamic performance of aortic prosthesis, with a special focus on the comparison between transcatheter and surgical aortic valves and between self-expandable and balloon-expandable valves. Moreover, the discussion will encompass how cardiovascular imaging can effectively detect long-term structural valve deterioration.

Is There Still a Role for Invasive Assessment of Aortic Gradient?

Advances in technology and imaging have expanded the range of tools for diagnosing aortic stenosis (AS). The accurate assessment of aortic valve area and mean pressure gradient is crucial to determine which patients are appropriate candidates for aortic valve replacement. Nowadays, these values can be obtained noninvasively or invasively, with similar results. Contrariwise, in the past, cardiac catheterization played a major role in the evaluation of AS severity. In this review, we will discuss the historical role of the invasive assessment of AS. Moreover, we will specifically focus on tips and tricks for properly performing cardiac catheterization in patients with AS. We will also elucidate the role of invasive methods in current clinical practice and their additional value to the information provided through non-invasive techniques.

Echocardiographic Evaluation after Transcatheter Aortic Valve Implantation: A Comprehensive Review

Transcatheter aortic valve implantation (TAVI) is an increasingly popular treatment option for patients with severe aortic stenosis. Recent advancements in technology and imaging tools have significantly contributed to the success of TAVI procedures. Echocardiography plays a pivotal role in the evaluation of TAVI patients, both before and after the procedure. This review aims to provide an overview of the most recent technical advancements in echocardiography and their use in the follow-up of TAVI patients. In particular, the focus will be on the examination of the influence of TAVI on left and right ventricular function, which is frequently accompanied by other structural and functional alterations. Echocardiography has proven to be key also in detecting valve deterioration during extended follow-up. This review will provide valuable insights into the technical advancements in echocardiography and their role in the follow-up of TAVI patients.

Acute advanced aortic stenosis

Acute decompensation often represents the onset of symptoms associated with severe degenerative aortic stenosis (AS) and usually complicates the clinical course of the disease with a dismal impact on survival and quality of life. Several factors may derange the faint balance between left ventricular preload and afterload and precipitate the occurrence of symptoms and signs of acute heart failure (HF). A standardized approach for the management of this condition is currently lacking. Medical therapy finds very limited application in this setting, as drugs usually indicated for the control of acute HF might worsen hemodynamics in the presence of AS. Urgent aortic valve replacement is usually performed by transcatheter than surgical approach whereas, over the last decades, percutaneous balloon valvuloplasty gained renewed space as bridge to definitive therapy. This review focuses on the pathophysiological aspects of acute advanced AS and summarizes current evidence on its management.

The role of Del Nido Cardioplegia in reducing postoperative atrial fibrillation after cardiac surgery in patients with impaired cardiac function

BACKGROUND

Postoperative atrial fibrillation (POAF) occurs in 20% to 40% of patients who underwent cardiac surgery and can compromise the postoperative course, especially in those with reduced left ventricular ejection fraction. The most common causes are related to surgical trauma and the high variations in volemic and electrolyte balance in the postoperative period.

OBJECTIVES

As cardioplegic solutions can significantly impact both these factors, the study aimed to assess the role of Del Nido (DN) cardioplegia on the onset of POAF.

METHODS

A retrospective single-center analysis was carried out on 93 patients undergoing coronary artery bypass graft surgery where cardioplegia was used. The patients were divided into two groups according to the cardioplegic solution (Cold Blood vs Del Nido), and perioperative outcomes were compared.

RESULTS

POAF occurred in 21.5% of patients; the patients treated with cold blood cardioplegia (CBC) showed a 3-times higher rate of POAF compared to the DN group (OR: 3.44; 95% CI: 1.1 to 10.5; p = 0.029). The CBC group showed higher serum potassium levels both after the cross-clamp removal (p<0.001), at the ICU admission (p = 0.007), and during the first 3 postoperative days (p = 0.009). The defibrillation rate at cross-clamp removal (p = 0.003), the dose of postoperative epinephrine (p<0.001), and the peak of serum troponin (p = 0.01), were lower in the DN Group.

CONCLUSION

DN cardioplegia showed significantly reduced POAF rates after cardiac surgery by acting on the electrolyte balance, myocardial protection and on the need for postoperative inotropic support.

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.

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.

689 IMPACT OF RENIN-ANGIOTENSIN SYSTEM INHIBITORS ON CLINICAL OUTCOME IN HYPERTENSIVE PATIENTS WITH SEVERE AORTIC STENOSIS UNDERGOING TRANSCATHETER AORTIC VALVE IMPLANTATION: INSIGHT FROM THE EFFECTAVI REGISTRY

Aims

Left ventricular pressure overload is connected with cardiac renin–angiotensin system activation, which may lead to myocardial fibrosis and poorer clinical outcomes. Hypertensive patients with symptomatic, severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI) in the EffecTAVI registry were evaluated for the association between baseline treatment with angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) and clinical outcomes.

Methods and results

The research comprised 373 patients with moderate, high, or prohibitive risk who had TAVI in the EffecTAVI registry (NCT05235555). Using Kaplan–Meier event rates and study-stratified multivariable Cox proportional hazards regression models, we evaluated clinical outcomes at 2 years according to ACEi/ARB therapy status at baseline. Among the 327 patients with hypertension included in the present study, 222 (67.9%) were treated with ACEI/ARB at baseline, whereas 105 (32.1%) were not. Treatment with ACEI/ARB was related with decreased all-cause mortality (HR=0.46, 95% CI 0.25-0.90, p=0.011), although this association was not statistically significant after multivariable adjustment for important covariates. Analyzing pre-procedural ACEi and ARBs separately, ARBs administration was related with a 58% decrease in all-cause mortality (HR=0.42, 95% CI 0.18-0.98, p=0.04), which was confirmed in multivariate analysis.

Conclusion

In a small cohort of hypertensive patients with severe symptomatic AS from the EffecTAVI registry, ARBs treatment at baseline was independently associated with a lower risk of 2-year all-cause mortality.

869 SUCCESSFUL TREATMENT OF COMBINED ANNULAR RUPTURE DURING TRANSCATHETER AORTIC VALVE IMPLANTATION: A CASE REPORT

Transcatheter aortic valve implantation (TAVI) has revolutionized the treatment of patients with severe, symptomatic aortic stenosis. Despite being less invasive than conventional open-chest surgery, TAVI remains associated with rare but serious complications such as vascular injury, stroke, coronary obstruction, cardiac perforation and annular rupture. We report a case of a combined annular rupture successful treated by emergent surgery. Case presentation: A low-risk (EuroSCORE:1.14%) 73-year-old male presenting with high-gradient, normal-flow severe aortic stenosis (AS) was referred to our centre. He had preserved left ventricular ejection fraction and heavily calcified aortic valve. The Heart Team recommended isolated surgical aortic valve replacement, but the patient refused this option. We decided to perform transfemoral-TAVI with a 26 mm Edwards valve which was deployed after predilatation with a 23 mm balloon. Immediately after valve deployment, the angiography revealed contrast leakage at the level of the Valsalva sinuses. The patient developed hypotension due to cardiac tamponade which was immediately managed with pericardial drainage. A bailout cardiac surgery was required to remove the TAVI prosthesis and the native aortic leaflets. A left ventricular outflow tract (LVOT) rupture was observed in addition to supra- annular and intra-annular injury. Repair of the left ventricle with a pericardial patch and implantation of a surgical bioprosthesis (Dafodil Meril 21 mm) were performed. No complications occurred post-operatively Annular rupture occurs in about 1% of all TAVI procedures and may involve the region of the aortic root and LVOT. According to the anatomical location of the injury, it can be classified into 4 types: intra-annular, sub-annular, supra-annular, and combined rupture. Annular rupture has been mainly observed after the use of balloon-expandable valves and only exceptionally after TAVI with self- expandable prosthesis. Nevertheless, the following anatomic characteristics are associated with an increased incidence of this catastrophic event: small aortic valve annulus (&lt;20 mm), a narrow aortic root, heavy calcifications of aortic valve leaflets, annulus, LVOT and sinuses of Valsalva, bicuspid valve, short distance from a coronary artery to the annulus and LV hypertrophy. The voluminous amount of calcification located in the landing zone in addition to the force applied during the balloon expansion may be the main mechanism of this catastrophic complication. Clinical presentation is dramatic and emergent surgery can be the sole solution. Alternative bailout treatments, such as placing a second transcatheter valve to close the rupture have been occasionally reported. A precise preprocedural analysis of the device landing zone is mandatory. This includes determination of the size, morphology of all anatomical structures and a careful identification of possible factors for annular rupture. Moreover, in these cases, the availability of cardiac surgery onsite is pivotal to save patient's life. As more and younger patient will undergo TAVI in next years, our report highlightsthe need to optimize preprocedural planning and prosthesis selection. Improvements in devices, procedural techniques, and imaging tools may simplify TAVI and reduce possible complications.

1050 ULTRASOUND GUIDED CANNULATION OF FEMORAL ARTERY IN PATIENTS UNDERGOING TRANSCATHETER AORTIC VALVE REPLACEMENT

Background

Vascular access complications are a significant source of morbidity and mortality after transcatheter aortic valve replacement (TAVR). Ultrasound-guided cannulation (UGC) of central veins or arteries is a widely used approach for patients undergoing invasive procedures. Whether UGC significantly decreases the risk of vascular access complications also for large-bore access procedures, such as TAVR, lacks evidence

Objectives

in this study, we aimed to evaluate the benefits of routine use of UGC in patients undergoing TAVR.

Methods

Data were retrospectively collected from two high-volume TAVR centers from September 2009 to March 2022. UGC was performed using a two-dimensional ultrasound short-axis views, while manual palpation, fluoroscopy, or contralateral angiography were used for the other patients. The odds ratio (OR) for vascular complications was calculated using a multivariate logistic regression model including as dependent variables all relevant baseline and procedural characteristics (forward stepwise selection process). Vascular complications were adjudicated according to the Valve Academic Research Consortium definitions 3.

Results

Out of 874 patients included in the study, UGC access was performed in 177 subjects. Overall mean age was 80.2±5.8 years old, 60% of patients were females, 35.5% had diabetes, 61.4% had dyslipidemia, and 27.8% had chronic kidney disease, with a mean left ventricular ejection fraction of 52.7±9.7%. Looking at the procedural variables Euroscore II was 5.8±5.4, second and third valves generation have been used in 85% of the cases, while suture-based closure devices in 84% of subjects. After adjustment for clinical and procedural variables, routinely use of UGC was associated with a lower rate of total [Odds Ratio (OR): 0.38; 95% confidence interval (CI) 0.15% to 0.95%)] and major vascular complications [Odds Ratio (OR): 0.21; 95% confidence interval (CI) 0.05% to 0.75%)], while no differences were observed for minor vascular complications.

Conclusions

Routinely use of UGC significantly decreases the risk of vascular complications in patients undergoing TAVR. However, a dedicated randomized clinical trial assessing the safety and efficacy of this approach is warranted to confirm our results in this high-risk population.

Impact of COVID-19 pandemic on timing and early clinical outcomes of transcatheter aortic valve implantation

BACKGROUND

We sought to investigate the applicability and outcomes of a novel system to manage patients requiring transcatheter aortic valve implantation (TAVI) at a tertiary level hospital during the coronavirus disease-2019 (COVID-19) pandemic.

METHODS

To analyse the impact of hospitalisation pathways during the pandemic on clinical outcomes of TAVI patients, the study population was divided into two groups (pre-pandemic and pandemic groups) and all perioperative/follow-up data were compared. The primary endpoint was all-cause mortality at 30 days; secondary endpoints included procedural success and short-term complications.

RESULTS

A total of 315 patients received TAVI during the study period. Pandemic group (n = 77) showed a more complex baseline clinical profile (NYHA class III-IV, 70.1% vs. 56.3%; p = 0.03). The overall time to procedure was significantly longer during pandemic (56.9 ± 68.3 vs.37.7 ± 25.4; p = 0.004) while intensive care unit stay was shorter (2.2 ± 1.4 vs. 3.7 ± 3.9, p < 0.05). Hospitalisation length was similar in both groups as well as all-cause mortality rate and the incidence of major periprocedural complications. No case of infection by COVID-19 was reported among patients during the hospital stay.

CONCLUSIONS

Comparative analysis of early clinical outcomes showed that COVID-19 pandemic did not affect the safety and effectiveness of TAVI as similar rates of procedural complications and all-cause mortality were reported than before February 2020. Despite the increased time lag between diagnosis and procedure and a more complex clinical profile of patients at baseline, the revised pathway of hospitalisation allowed to resume inpatient procedures while not affecting patients' and healthcare workers' safety.

Prognostic role of global work efficiency in patients undergoing transcatheter aortic valve implantation

Background

Non-invasive myocardial work (MW) quantification has emerged in the last years as an alternative echocardiographic tool for myocardial function assessment. Its role in patients with severe aortic stenosis (AS) after aortic valve implantation (TAVI) has not been adequately investigated.

Purpose

We aimed to evaluate MW indices as early echocardiographic markers of LV reverse remodeling within a month after TAVI and their prognostic value.

Methods and results

We conducted a single-centre prospective study, enrolling 88 consecutive patients (mean age 79.9±6.4 years, 35% males) with AS undergoing TAVI between April 2018 and 2021, selected from the EffecTAVI registry. Exclusion criteria were prior valve surgery, atrial fibrillation, left bundle branch block (LBBB) at baseline and and suboptimal quality of imaging. Echocardiographic assessment was performed before TAVI and at 30-day follow-up, including quantification of 2D global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW) and global work efficiency (GWE). LV peak systolic pressure was estimated non-invasively from the sum of systolic blood pressure and trans-aortic mean gradient. One month after the procedure, there was a significant improvement of LV GLS (−18.4±4.2 vs −19.5±4.2%, before and after TAVI respectively, p=0.006), a significant reduction of GWI (2406±567 vs 1908±479 mmHg%, p&lt;0.001), GCW (2783±616 vs 2202±463 mmHg%, p&lt;0.001), and GWW (238±203 vs 173±127 mmHg%, p=0.002). Conversely, MWE did not change early after intervention (90.4±6.2 vs 91.4±5.1%, p=0.113). After TAVI, 32 patients (36.4%) developed LV dyssynchrony due to LBBB or pacemaker implantation. When the population was divided according to the presence or absence of LV dyssynchrony at 30-day follow-up, a significant reduction in GWW was found only in the those without dyssynchrony (241±229 vs 142±103 mmHg% before and after TAVI, p&lt;0.001). Consistently, in this subgroup, MWE significantly improved after TAVI (90±7 vs 93±5%, p=0.001), while a trend of MWE reduction was observed in patients who developed dyssynchrony after TAVI (91±5 vs 89±5%, p=0.110). In the overall population, a 30-day value of MWE≤92% was associated with an increased rate of cardiovascular events (composite of all-cause death and rehospitalization for heart failure) at 1-year follow-up (29.5% vs 4.8%, long rank p=0.003). In multivariable Cox-regression analysis, adjusted for confounders, GWE after TAVI (HR: 0.892, CI: 0.817–0.974; p=0.011) was independently associated with events at 1-year follow-up.

Conclusions

In patients with severe AS undergoing TAVI a significant reduction of GWW and improvement of MWE can be detected only in those who do not develop LV dyssynchrony. In this setting, MWE≤92% early after TAVI is associated with poor outcome. Thus, MWE could represent an alternative tool for myocardial function assessment and prognostic evaluation in patients receiving TAVI.

Funding Acknowledgement

Type of funding sources: None.

Impact of posterior pericardial drain and risk factors on late pericardial effusion after coronary artery bypass surgery

BACKGROUND

The blood retained in posterior pericardium can trigger an inflammatory response that increases postoperative atrial fibrillations (POAFs), and it can complicate postoperative course. We retrospectively investigated the impact of a posterior pericardial drain (PPD) in reducing late postoperative pericardial effusion (pPE) and POAFs during the first 30 postoperative days.

METHODS

Two hundred and fifty coronary artery bypass grafting patients were divided into two groups according to the presence of a PPD in addition to the anterior one. Perioperative data and the incidence of POAF were compared. Risk factor analysis was used to determine the predictors of pPE and postpericardiotomy syndrome.

RESULTS

Late pPE was present in 16% of all patients. It proved to be much more frequent in patients with a posterior drain (odds ratio 2.58; 95% confidence interval 1.23-5.79; P = 0.015) where it seemed to be almost mild and anterior. 'Anterior Drain' patients showed an increased rate of moderate (P < 0.001) and posterior effusions (P < 0.001). POAF was much more frequent in patients without a PPD (25.2 vs. 6.3%; P < 0.001). Univariate risk factor analysis revealed a significant association between late pPE and lower preoperative weight (P = 0.003), lower preoperative and postoperative serum albumin (P < 0.001) and a greater amount of blood transfusion (P = 0.02).

CONCLUSION

Even if a PPD is associated with a higher rate of pPE, the patients with only anterior drains were shown to have a greater amount of pericardial effusion and an increased risk of POAFs. Therefore, a PPD should be considered to improve postoperative course.

P-267 A continuous culture medium with a lower concentration of lactate has a pronounced effect on the percentage of usable blastocysts on day 5

Study question

Does Continuous Single Culture Medium NX, an embryo culture medium containing 1mM lactate, support increased blastocyst development over high lactate Vitrolife G1/G2 Series sequential culture?

Summary answer

There is a statistically significant increase in day 5 usable blastocysts in low lactate culture medium compared to the one with high lactate medium.

What is known already

Studies have shown that day 5 is the most desirable day to obtain blastocysts that are of an expansion, grade and quality to be utilized for transfer and/or vitrification procedures as those result in the highest success of clinical pregnancy,as compared to day 6/ 7 blastocysts, that do not meet criteria. Moreover, recent studies have indicated that there is an increase in chromosomal correctness of embryos cultured in a 1mM lactate environment as opposed to the higher 6-10mM lactate concentrations that have historically been believed necessary for successful blastocyst culture and resulting pregnancy.

Study design, size, duration

A prospective split sibling oocytes study was performed on 50 ICSI and IMSI cycles from October 2020 through April 2021. Oocytes were divided into the low lactate medium and high lactate gradient medium immediately following ICSI/IMSI and thereafter cultured in those medium until the final day of blastocyst culture. All patient ages were included in the sample population.

Participants/materials, setting, methods

This study was carried out in a private clinic. All patient stimulation protocol information and diagnosis’ were recorded; however, there was no restriction on participation. The endpoint was to analyse the resulting usable blastocyst rates on day 5 and day 6 in both arms of the study, using a denominator of normal 2PN fertilization. If a blastocyst was transferred or cryopreserved on day 5 or day 6, it was determined to be usable.

Main results and the role of chance

The resulting data was stratified not only by day 5 and day 6 usable blastocyst rates but also by patient age. It illustrates a statistically significant improvement in day 5 usable blastocysts for patients &lt;35 in CSCM-NXC vs G1/G2 at 56% and 42%, respectively, a 14% increase (p &lt; .05). The overall day 5 usable blastocyst rate was also statistically significant in CSCM-NXC (47%) as compared to G1/G2 (36%), (p &lt; .05) with all ages considered. Additionally, on day 5, there was a higher percentage of usable blastocysts demonstrated in low lactate vs high in patients aged 35-37 (65% vs 42%, respectively) and 41-42 (41% vs 15%). Statistical significance was reversed in patients &lt;35 on day 6, with G1/G2 having 24% usable blasts and CSCM-NXC 10% (p &lt; .05). Interestingly, though not significant, G1/G2 had an increase in usable blastocyst percentage on day 5 in patients &gt;42 (20% vs 11%), but overall, CSCM-NXC saw an increase in that same age group by 16%.

Limitations, reasons for caution

Though statistical significance was found in this study, a greater number will help to bolster the statistical power of the observations. Additionally, more studies are needed in order to ascertain if low lactate has an effect on the development prior to ICSI and resulting culture.

Wider implications of the findings

The mechanism of action that leads to the successful embryo development in low lactate embryo culture medium is vastly unknown, so further studies are required in order to understand the complexities and the impact of the observations provided.

Trial registration number

not applicable.

P-260 Study of kinetic parameters using KIDscoreTMDay5 version 3.0 in euploid, mosaic and aneuploid blastocysts

Study question

Do kinetic parameters change among euploid, mosaic and aneuploid blastocysts? Is the KIDscoreTMDay5 version 3.0 (KS-5.3) correlated to preimplantation genetic testing for aneuploidies (PGT-A) results?

Summary answer

The KS-5.3 differs in embryo ploidy classes. The analysis of the kinetic variables showed that the aneuploid embryos were significantly slower than euploid and mosaic.

What is known already

Chromosomal abnormalities affect more than 50% of embryos in women with &gt;35 years of age and PGT-A is the best way to predict embryo’s ploidy status decreasing implantation failure and miscarriage. However, this procedure is not always possible due to social or moral issues. So, the use of the non-invasive time lapse monitoring could be helpful to determine the morphokinetic characteristics in the different ploidy classes. KS-5.3 (vitrolife,Sweden) is a scoring model based on morphokinetic data, developed to predict the pregnancy rate of day-5 blastocysts. Recent publications showed differences in kinetic parameters between euploid and aneuploid embryos.

Study design, size, duration

This retrospective study analyzed 728 blastocysts with PGT-A results obtained at Villa Mafalda Clinic from May 2020 to June 2021. Embryos were cultured in EmbryoScope+ time-lapse system (Vitrolife) at 37 °C, 6%CO2, and 5% O2. The PGT-A was performed using next-generation sequence (NGS) technology on the trophectoderm biopsy sample on day 5/6/7. Automatic annotations for division times and quality gradings were performed by senior embryologists and all kinetic values were reported in hours post microinjection.

Participants/materials, setting, methods

728 blastocysts were classified in: (E) euploid (n = 172), (M) mosaicism (n = 171) and (A) aneuploid (n = 385). In this study, they were considered KS-5.3 and the following kinetic variables: the time to reach 2 cells (t2), 3 cells (t3), 4 cells (t4), 5 cells (t5), and the blastocyst formation (TB). Continuous variables were reported as the median and interquartile range (IQR). For the statistical analysis, nonparametric tests were performed and p &lt; 0.05 was considered statistically significant.

Main results and the role of chance

KS5.3 was significantly different between groups [E = 6.6(4.6-7.9) vs M = 5.3(2.9-7.2) vs A = 4.0(2.5-6.6), p &lt; 0.0001]. It was significantly higher in euploid than in mosaic and aneuploid (EvsM p = 0.0007, EvsA p  &lt;0.0001, MvsA p = 0.0077). A significant delay in t2,t3,t4 and tb was showed in aneuploid embryos compared to euploid and mosaic, whereas there was no significant difference between euploid and mosaic: [t2: E = 25.80 (24.56-28.09), M = 25.99 (24.49-28.91), A = 27.02 (25.30-29.47), EvsA p  &lt;0.0001, AvsM p = 0.03, EvsM p = 0.32]; [t3: E = 37.08 (34.74-39.34), M = 36.69 (34.55-40.02), E = 38.45 (35.93-41.14), EvsA p = 0.0003, MvsA p = 0.002, EvsM p &gt;0.99]; [t4: E = 38.28 (35.63-41.19), M = 38.49 (35.47-42.13), A 39.72 (37.25-43.31), EvsA p = 0.0001, MvsA p = 0.02, EvsM p = 0.65]; [tb: E = 107.70 (102.20-114.30), M = 110.10 (103.60-116.80), A = 113.7 (106.80-122.70), EvsA p  &lt;0.0001, MvsA p  &lt;0.0001, EvsM p = 0.42]. As for t5, there were no differences among the groups. Longer cell cycles in aneuploid embryos could be associated with activated DNA repair mechanism or during chromosome segregation. Instead, regarding the mosaics, there was a significant difference with euploid embryos only in KS5.3. The age was similar between euploid and mosaic [E = 36.29 (33.42-39.00) vs M = 36.71 (34.00-39.33) p = 0.99], whereas that was significantly higher in aneuploid embryos [A = 39.11(36.01-42.27), EvsA/EvsM p  &lt;0.0001].

Limitations, reasons for caution

All these findings have to be validated in a larger sample size. Furthermore, for the retrospective nature of this study, there were some confounding factors, such as protocol of stimulation, female age, and malefactor. This research did not consider the importance of every single kinetic parameter.

Wider implications of the findings

A further study is needed to verify if there is a correlation between morphology and ploidy status. This could clarify the difference in KS-5.3 between euploid and mosaic. In order to decrease age bias, we should enlarge the sample size to analyze a subgroup of patients with higher maternal age.

Trial registration number

not applicable

Incidental finding of rare and huge asymptomatic pseudoaneurysm after Bentall procedure: A challenging case report

We report the case of a 62-year-old male who underwent urgent cardiac surgery due to the incidental finding of a huge and asymptomatic coronary button pseudoaneurysm at an 18-month outpatients clinic follow-up requiring a very complex preoperative planning.

143 Incidence, predictors, and clinical impact of transient left bundle branch block in patients undergoing transcatheter aortic valve implantation

Aims

This study aims to evaluate the incidence and prognostic impact of transient left bundle branch block (LBBB) in patients undergoing transcatheter aortic valve implantation (TAVI) with balloon-expandable or self-expanding valves. Clinical, echocardiographic and electrocardiographic predictors of transient LBBB were also investigated.

Methods and results

197 patients treated with TAVI at Federico II University hospital, Naples, Italy were enrolled. Electrocardiograms (ECGs) were obtained before and after TAVI procedure, at discharge and at 30-day follow-up. ECGs were anonymously digitalized and analysed by five cardiologists. Transient LBBB was defined as LBBB regressed within 30 days after procedure. All ECGs for each patient were analysed by the same cardiologist. The primary endpoint of the study was all-cause mortality and permanent pacemaker implantation (PPI) at 1-month after TAVI. Secondary endpoints included cerebrovascular accidents, acute myocardial infarction, vascular complications, acute kidney injury, endocarditis, and re-hospitalization for all causes. Out of 197 patients enrolled, 54 (27.4%) developed transient LBBB. Among patients with transient LBBB, 70.4% were female. Mean age was higher in transient LBBB group compared with control group (81.0 ± 6.4 years, vs. 78. 6 ± 6.5 years; P = 0.022). From logistic analysis, peak transvalvular gradient (OR: 1.01, 95% CI: 0.93–1.00; P &lt; 0.034) and left ventricular ejection fraction (LVEF) (OR: 0.96, 95% CI: 0.93–0.99, P &lt; 0.012) were identified as predictive factors of transient LBBB. No differences between the two studied groups were observed in primary and secondary endpoints (all-cause mortality: 1.9% vs. 0.7%; P = 0.46; PPI: 9.6% vs. 12%; P = 0.80).

Conclusions

Peak transvalvular gradient and LVEF predict onset of transient LBBB, a common conduction disturbance after TAVI. Onset of transient LBBB does not correlate with worse clinical outcomes at 30 days.

652 Myocardial work in patients undergoing transcatheter aortic valve implantation: clinical value and implications for outcome

Aims

Non-invasive myocardial work (MW) quantification has emerged in the last years as an alternative echocardiographic tool for myocardial function assessment. This new parameter provides a less loading-dependent evaluation of myocardial performance through the combined assessment of global longitudinal strain (GLS) and non-invasive left ventricle (LV) pressures. The role of MW as a marker of cardiac dysfunction and reverse remodelling in patients with severe aortic stenosis (AS) after aortic valve implantation (TAVI) has not been adequately investigated. This study aims to evaluate MW indices as early echocardiographic markers of LV reverse remodelling within a month after TAVI and their prognostic value.

Methods and results

We conducted a single-centre prospective study, enrolling 70 consecutive patients (mean age 80.1 ± 5.5 years) with severe AS undergoing TAVI between 2018 and 2020, selected from the EffecTAVI registry. Exclusion criteria were prior valve surgery, severe mitral stenosis, permanent atrial fibrillation, left bundle branch block (LBBB) at baseline, and suboptimal quality of speckle-tracking image analysis. Echocardiographic assessment was performed before TAVI and at 30-day follow-up. Clinical, demographic, and resting echocardiographic data were recorded, including quantification of 2D global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). LV peak systolic pressure was estimated non-invasively from the sum of systolic blood pressure and trans-aortic mean gradient. One month after the procedure, there was a significant improvement of LV GLS (−17.94 ± 4.24% vs. −19.35 ± 4.31%, before and after TAVI respectively, P = 0.002), as well as a significant reduction of GWI (2430 ± 586 mmHg% vs. 1908 ± 472 mmHg%, P &lt; 0.001), GCW (2828 ± 626 mmHg% vs. 2206 ± 482 mmHg%, P &lt; 0.001), and GWW (238 ± 207 mmHg% vs. 171 ± 118 mmHg%, P = 0.006). Conversely, MWE did not significantly change early after intervention (90.53 ± 6.05% vs. 91.45 ± 5.05%, P = 0.204). After TAVI, 30 patients (42.8%) developed LV dyssynchrony due to LBBB or pacemaker implantation. When the population was divided according to the presence or absence of LV dyssynchrony at 30-day follow-up, a significant reduction in GWW was found only in those without dyssynchrony (244 ± 241 vs. 141 ± 110 mmHg% with and without dyssynchrony respectively, P = 0.002). Consistently, in this subgroup, MWE significantly improved post-TAVI (90 ± 7 vs. 93 ± 5%, P = 0.002), while a trend of MWE reduction was observed in patients who developed dyssynchrony post-TAVI (91 ± 4 vs. 89 ± 5%, P = 0.164). In the overall population, a baseline value of MWE&lt; 92% was associated with an increased rate of cardiovascular events (composite of all-cause death and rehospitalization for heart failure) at 1-year follow-up (22.2 vs. 3.1%, long rank, P = 0.016).

Conclusions

In patients with severe AS undergoing TAVI a significant reduction of GWW and improvement of MWE can be detected only in those who did not develop LV dyssynchrony. In this setting, MWE lower than 92% at baseline is associated with poor outcome. Thus, MWE could represent an alternative tool for myocardial function assessment in patients receiving TAVI.

134 Impact of COVID-19 pandemic on timing and early clinical outcomes of transcatheter aortic valve implantation

Aims

COVID-19 pandemic deeply changed the management of patients with aortic stenosis. Many cardiac societies have drawn up guidelines for the optimal management of this population but applicability of such recommendations in the current clinical practice and their impact on clinical outcomes has not been adequately investigated.

Methods and results

A single-centre retrospective study included 315 patients undergoing transcatheter aortic valve implantation (TAVI) between April 2017 and June 2021. To analyse the impact of hospitalization pathways during the pandemic on clinical outcomes of TAVI patients, study population was divided into two groups (pre-pandemic and pandemic groups) and all perioperative/follow-up data were compared. The primary endpoint was all-cause mortality at 30 days; secondary endpoints included procedural success and short- term complications. Pandemic group patients showed a more complex baseline clinical profile (NYHA III–IV, 70.1% vs. 56.3%; P = 0.03). The overall time to procedure was significantly longer during pandemic (56.9 ± 68.3 vs.37.7 ± 25.4; P = 0.004) while intensive care unit stay was shorter (2.2 ± 1.4 vs. 3.3 ± 3.5). Hospitalization length was similar in both group as well as all-cause mortality rate and the incidence of major periprocedural complications.

Conclusions

COVID-19 pandemic did not affect the safety and effectiveness of TAVI as similar rates of procedural complications and all-cause mortality were reported than before February 2020. Despite the increased time lag between diagnosis and procedure and a more complex clinical profile of patients at baseline, the revised pathway of hospitalization allowed to resume inpatient procedures while not affecting patients’ and healthcare workers’ safety.

676 Impact of transcatheter aortic valve implantation in patients with severe aortic stenosis and concomitant mitral regurgitation

Aims

Severe aortic stenosis (AS) and functional mitral regurgitation (MR) frequently coexist. There is no consensus about the optimal therapeutic strategy for patients with combined valve disease. Evidence has shown that double valve surgery is associated with high complication rates and mortality, whereas MR severity may improve after transcatheter aortic valve implantation (TAVI). To date, little is known on prognostic parameters associated with MR improvement after TAVI. Recently, a new echocardiographic parameter based on the ratio between peak E velocity and peak atrial longitudinal strain (E/PALS) has demonstrated to be accurate and sensitive in the prediction of elevated filling pressure. Its role in the setting of AS patients undergoing TAVI has never been investigated. Our study aims to evaluate haemodynamic conditions and left ventricular (LV) systolic and diastolic function in patients with severe AS and concomitant MR undergoing TAVI and to identify new echocardiographic parameters associated with MR improvement 1 month after the aortic valve replacement.

Methods

We prospectively enrolled 87 consecutive patients (mean age 80 ± 6 years) with severe symptomatic AS and concomitant MR undergoing TAVI between 2016 and 2021, for whom a complete echocardiographic assessment was available at baseline and 1 month after the procedure, selected from the EffecTAVI registry. Exclusion criteria were prior valve surgery, severe mitral stenosis, permanent atrial fibrillation, and poor ultrasound acoustic window. Echo-Doppler assessment, including global longitudinal strain (GLS) and peak atrial longitudinal strain (PALS), was performed before and after 1 month to TAVI procedure. Changes (Δ) of the main echo parameters before and after intervention were computed.

Results

A month after the procedure, 20 (23%) patients had a reduction of at least one degree of MR (P &lt;0.001). Dividing study population in two groups, based on whether or not MR was reduced after TAVI, we found that patients with MR improvement had higher LV end-diastolic volume (P = 0.036) and left atrial volume (P = 0.015) at baseline compared with those without MR reduction. After TAVI no significant differences were found in heart chambers size between the two groups, but a significant increase in PALS (23.2 ± 7.3 vs. 22.3 ± 7, P=0.028), together with a reduction in E/A ratio (0.69 ± 0.14 vs. 0.90 ± 0.46, P = 0.046) were detected in patients with MR reduction. Furthermore, Δ E/PALS (−17.3±34.4% vs. 3.9±35.0% P=0.027), Δ E/A (−12.6±33.9% vs. 24.7±64.3%, P=0.018) and Δ systolic pulmonary artery pressure (sPAP) (−13.0±20.2% vs. −2.0±18.3, P=0.031) were significantly higher in patients with MR improvement to compared those without MR reduction. By the multivariate logistic regression analysis performed in the pooled population, Δ E/PALS (OR 0.968, 95% CI: 0.947–0.990, P=0.005), together with LV mass at baseline (OR 1.056, 95% CI: 1.007–1.107, P = 0.024) appeared to be independently associated with MR reduction post-TAVI.

Conclusions

Our study demonstrated that: after TAVI in a significant percentage of patients a relevant improvement in concomitant MR was detected; in the group of patients with improved MR a parallel improvement of sPAP, E/A and E/PALS ratio post TAVI was found; Δ E/PALS appears to be the main parameter independently associated with the reduction of MR severity.

Preoperative Aspirin Management in Redo Tetralogy of Fallot Population: Single Centre Experience

Purpose: Redo operations and preoperative antiplatelet/anticoagulant therapy can significantly increase surgical risk in congenital heart surgery. This is a retrospective study on the impact of preoperative aspirin therapy on the outcome of Tetralogy of Redo Fallot patients undergoing right ventricle outflow tract (RVOT) conduit implantation. Methods: Ten-years retrospective analysis of medical records was carried out. A total of 72 patients were divided into two groups: “Daily-on-ASA” group on daily therapy with aspirin (ASA) until 5 days from surgery and “No-Home-ASA” without it. Propensity match analysis was done in order to standardize the populations. Intraoperative and postoperative lengths were compared as well as the need for inotropic support. In addition, differences in blood transfusions and need for Fresh frozen plasma (FFP)/platelets (PLT) were analysed. Findings: Intraoperative lengths were similar between the groups. Not statistically significative differences about postoperative time to extubation (p = 0.34), ICU Stay (p = 0.31) or in-hospital stay (p = 0.36) were found. Drain loss was higher in the “Daily-on-ASA” group (407.9 ± 96.7 mL vs. 349.5 ± 84.3 mL; p = 0.03) as well as blood transfusions (372.7 ± 255.1 mL vs. 220.1 ± 130.3 mL, p = 0.02) and PLT/FFP need (217.7 ± 132.1 mL vs. 118.7 ± 147.1 mL, p = 0.01). No differences were found in postoperative complications or re-explorations for bleeding. Implications: We found no advantages in surgical times and hospital stay comparing redo patients who stopped aspirin versus those that didn’t take it in the last 6 months. However, our results suggest that redo patients undergoing RVOT conduit implantation who take daily aspirin are at higher risk of bleeding even if it is stopped 5 days before surgery.

Mechanical complications of myocardial infarction during COVID-19 pandemic: An Italian single-centre experience

COVID-19 pandemic triggered in many patients the fear to go to the emergency rooms in order to avoid a possible infection. This phenomenon caused a significant reduction in acute coronary syndrome-related interventional procedures with a subsequent increase in critical hospitalizations and post-infarction mechanical complications. A case series of cardiac ruptures during the COVID-19 lockdown and the surgical treatment of a huge post-ischemic cardiac pseudoaneurysm complicated by a “contained” free wall rupture are presented.

Translational Research: A Future Strategy for Managing Squamous Cell Carcinoma of the Head and Neck?

BACKGROUND

Squamous Cell Carcinoma of the Head and Neck (SCCHN) are neoplasms arising from the epithelium of the first aero-digestive tract. They are very heterogeneous both clinically and biologically. Classic and well acknowledged risk factors are alcohol and tobacco consumption and other forms of smokeless tobacco assumption, although lately the incidence of Human Papilloma Virus (HPV)-related SCCHN is rapidly increasing. HPV-related tumors are very different from their alcohol and tobacco-associated counterpart, as they show strong chemo and radio sensitivity and thus can often be treated with conservative treatment strategies. Moreover, peculiar biologic features characterize HPV-related tumors, such as wild type TP53, low expression of Epidermal Growth Factor Receptor (EGFR), wild type CCND1 and high expression of P16. In contrast, alcohol and tobacco related SCCHN show opposite features, together with higher number of chromosomal and genetic abnormalities, conferring them chemo and radio resistance.

METHODS

We have performed a narrative review of the PubMed database with the aim to study the mutational landscape of SCCHN.

RESULTS

Several lines of evidence support the existence of at least two genetically different types of SCCHN, one virus-related and the other alcohol and/or tobacco-related, characterized by both clinical and biological opposite features. Virus related SCCHN are very chemo and radiosensitive, so suitable for organ preserving strategy, which in the near future may be induction chemotherapy followed by association of chemotherapy and underpowered radiotherapy. Alcohol and tobacco related SCCHN are themselves strongly heterogeneous and can be divided in different entities on the basis of the "Driver" genetic aberration, responsible for carcinogenesis. The most frequently mutated genes in alcohol and tobacco-related SCCHN are TP53, NOTCH1, CCND1, CDKN2A, EGFR and PI3KCA.

CONCLUSIONS

Virus-related SCCHN can be managed with chemo-radiotherapy. Alcohol and tobacco-related tumors should be further characterized on the basis of their "Driver Mutations" in order to select effective targeted therapies.

Modeling birds on wires

In this paper we introduce a mathematical model to study the group dynamics of birds resting on wires. The model is agent-based and postulates attraction-repulsion forces between the interacting birds: the interactions are "topological", in the sense that they involve a given number of neighbors irrespective of their distance. The model is first mathematically analyzed and then simulated to study its main properties: we observe that the model predicts birds to be more widely spaced near the borders of each group. We compare the results from the model with experimental data, derived from the analysis of pictures of pigeons and starlings taken in New Jersey: two different image elaboration protocols allow us to establish a good agreement with the model and to quantify its main parameters. We also discuss the potential handedness of the birds, by analyzing the group organization features and the group dynamics at the arrival of new birds. Finally, we propose a more refined mathematical model that describes landing and departing birds by suitable stochastic processes.

Optimization versus randomness for car traffic regulation

We focus on the differences among the analytical optimization of traffic flow on a road network, modeled by a fluid-dynamic approach, and a dynamic random one. In particular, two real urban networks are analyzed: Re di Roma Square, in Rome, and Via Parmenide crossing, in Salerno. With such two examples, it is possible to show that dynamic random algorithms are not the right choice for the improvement of traffic conditions.

Effect of ascorbic acid based amphiphiles on human erythrocytes membrane

6-O-alkyl ascorbic acid esters (ASCn) are amphiphilic molecules that behave as surfactants in aqueous solution. These compounds show physico-chemical and aggregation properties that depend on the alkyl chain length, pH and temperature. It must consider that ASCn have shown some physical and rheological properties that suggest a potential utility as drug carriers. The present paper aims to evaluate the effects of these surfactants on human erythrocyte membranes. The membrane properties studied were: osmotic resistance in hypotonic media, shape transformation, and vesicle release at lytic concentration. According to our results, all properties depended on the length of the hydrophobic chain and they did not evolve monotonically. Finally, the study of ASCn interaction with erythrocyte membrane allowed us to postulate the crucial influence that the molecular structure exerts upon the manner in which amphiphiles interact with biological membranes and the effects involved in them.

Conception rates and serum progesterone concentration in dairy cattle administered gonadotropin releasing hormone 5 days after artificial insemination

The objectives of this study were to determine the effect of administration of exogenous GnRH 5days after artificial insemination (AI) on ovarian structures, serum progesterone concentration, and conception rates in lactating dairy cows. In experiment 1, 23 Holstein cows were synchronized using the Ovsynch protocol. Five days after AI (day 0) cows were assigned randomly to receive either saline (saline; n=11) or 100microg GnRH (GnRH; n=12). To examine ovarian structures, ultrasonography was performed on day 1 and every other day beginning on day 5 until day 13. On days 5 and 13 blood samples were obtained to measure serum progesterone concentrations. All cows in the GnRH-treated group developed an accessory corpus luteum (CL), whereas cows in the saline group did not. Mean serum progesterone concentrations did not differ between GnRH and saline groups on day 5 (1.64+/-0.46ng/ml versus 2.04+/-0.48ng/ml). On day 13 serum progesterone concentrations were greater (P<0.05) in the GnRH group compared with saline (5.22+/-0.46ng/ml versus 3.36+/-0.48ng/ml). In experiment 2, 542 lactating cows, at two different commercial dairies, were used to test the effect of administering GnRH 5 days after AI on conception rates. Cows were synchronized and detected for estrus according to tail chalk removal. Cows detected in estrus received AI within 1h after detection of estrus. Five days after AI, cows were assigned randomly to receive either GnRH (n=266) or saline (n=276). Pregnancy status was determined by palpation per rectum of uterine contents approximately 40 days after AI. There was no effect of farm on conception rate. There was no effect of treatment as conception rates did not differ between GnRH and saline groups (26.7% GnRH versus 24.3% saline). Regardless of treatment, days in milk, parity, milk yield, and number of services had no effect on the odds ratio of pregnancy. In summary, the results of this study indicated that GnRH administered 5 days after AI increased serum progesterone by developing an accessory CL but did not improve conception rates in dairy cattle.

Time and Incidence of Ovulation and Conception Rates After Incorporating Estradiol Cypionate into a Timed Artificial Insemination Protocol

Two experiments were conducted to determine the effect of estradiol cypionate (ECP), when incorporated into a conventional GnRH-PGF(2alpha)-GnRH timed artificial insemination protocol (Ovsynch), on systemic estradiol (E(2)), time and incidence of ovulation, luteal development, and conception rate in Holstein cows. Our objective was to determine if administration of 0.25 mg of ECP at the time of the second GnRH injection would effectively synchronize ovulation and increase conception rate. In Experiment 1, lactating Holstein cows (n = 23; 58.7 +/- 1.2 d in milk) were synchronized with PGF(2alpha) (at d -10). Ten days later, Ovsynch was initiated with the administration of 100 mug of GnRH (d 0) followed by PGF(2alpha) on d 7. On d 9, cows were assigned randomly to be treated with either GnRH + 0.25 mg of ECP (OVS-ECP; n = 11) or GnRH and 1 mL of cottonseed oil (OVS-C; n = 12). Ovarian activity was monitored by ultrasonography on d 0, 7, and 9. To determine the time of ovulation, ultrasound examinations were conducted at 12 and 20 h posttreatment and then at least every 3 h until either 36 h posttreatment or ovulation was observed. Blood samples were collected on d 0, 7, 9, and 16 for progesterone analysis. Blood samples also were collected at the time of treatment (d 9, 0 h) and at 6, 12, 20, and 28 h for E(2) analysis. Incidence of ovulation did not differ between treatments. Mean ovulation time relative to the second GnRH administration was similar between treatments. Serum progesterone concentration did not differ between treatments at any time. Serum E(2) concentration was not different at the time of treatment (0 h); however, mean E(2) concentration was greater for the OVS-ECP group at 6 and 12 h after treatment compared with OVS-C. In Experiment 2, lactating dairy cows (n = 333) in 3 commercial herds were randomly assigned to OVS-ECP (n = 169) or OVS-C (n = 164). Cows were inseminated 22 to 24 h posttreatment. Conception rates did not differ between treatments. Estradiol cypionate treatment was successful in increasing serum E(2) when administered at the time of the second dose of GnRH in the Ovsynch protocol. Conception rates, however, were not affected by treatment.

Short Communication: Conception Rates Following Detection of Estrus and Timed AI in Dairy Cows Synchronized Using GnRH and PGF2

The objective of this study was to compare conception rates of cows exhibiting spontaneous estrus and receiving artificial insemination (AI) before completion of a timed AI protocol with cows that did not display estrus spontaneously, but were inseminated after 1 of 3 GnRH-PGF2alpha protocols. Cows (n = 432) in 2 herds were administered GnRH on d -7 and were tail-chalked daily. Cows detected in estrus before d 0 were inseminated immediately. Cows not detected in estrus by d 0 were administered PGF2alpha and were tail-chalked daily until 48 h after PGF2alpha. Cows detected in estrus from d -7 to 48 h after PGF2alpha were inseminated and designated as treatment A (n = 46). Cows not detected in estrus and not inseminated by 48 h after PGF2alpha were assigned randomly to receive either GnRH 48 h after PGF2alpha and timed AI 16 h later (treatment B; n = 132), or GnRH and timed AI 64 h after PGF2alpha (treatment C; n = 127), or timed AI 64 h after PGF2alpha (treatment D; n = 127). Pregnancy was diagnosed 38 to 45 d after AI by palpation per rectum of uterine contents. Nearly 11% of all cattle exhibited spontaneous estrus and received immediate AI. Herd did not influence the percentage of cows detected in estrus and inseminated. Conception rates did not differ among treatments. Conception rates differed between herds, but no interaction of herd x treatment was detected. No differences were detected between herds for days in milk, milk production, AI service number, or parity.

Radiologist evaluation of a multispectral image compression algorithm for magnetic resonance images

With the advent of teleradiology and picture archiving and communication systems (PACS), the expense and time required for image transmission and long term image archiving become important. The use of validated image compression algorithms can greatly reduce these costs. A lossy, multispectral image compression scheme at compression ratios (CR) of 25:1 and 32:1 was used for a set of 26 different patient MR exams. The original and compressed/decompressed (CD) images sets were evaluated in a blinded fashion by four radiologists in two phases. The main objective was to determine whether radiologic interpretation would vary between the two types of CD image sets and the corresponding originals. In general, the compression algorithm caused a slight decrease in image quality; however, the interpretation of pathology did not change between the original and CD image sets. In only one case at the maximum CR = 32 did one of four radiologists change the interpretation of pathology after CD. In this study, lossy multispectral image compression of MR images at CR = 25 maintained diagnostic integrity. This could play a significant role in image storage and communications.