Real-world survival of model-3501 subcutaneous implantable defibrillator lead

Funding Acknowledgements

Type of funding sources: None.

Background

In December 2020, the subcutaneous implantable cardioverter-defibrillator (S-ICD) lead model-3501 was subject to a safety notification because of increased risk of fracture at a location just distal to the proximal sense ring. The manufacturer’s product performance report currently reports a lead survival probability of 98.8% at 45 months. However, no multicenter long-term performance information exists for this lead.

Purpose

Our aim was to assess the longevity of model-3501 leads and to compare it with that of the previous model-3401.

Methods

This analysis included consecutive patients who received an S-ICD with a model-3501 or a model-3401 lead at 66 Italian participating centers of the Rhythm Detect registry. A lead failed if it required extraction/replacement because of abnormalities suggestive of a structural defect, e.g. out-of-range impedance, nonphysiological electrical noise or ineffective therapy.

Results

From January 2013 to July 2021, 2403 patients were implanted and followed up (78% male, age 49±15years, ejection fraction 45±16%, body mass index 26±4Kg/m2). A 3501-model lead was used in 1697 patients and a 3401-model in 706 patients. During a median follow-up of 38 months [25th–75th percentile: 24-55], we detected 4 malfunctioning model-3501 leads and 2 model-3401 leads. After analysis of the returned leads by the manufacturer’s technical services, a single model-3501 lead failure was a fracture distal to the proximal ring electrode, as described in the manufacturer’s advisory letter. No deaths or permanent injuries occurred as a result of lead failures. The survival of 3501-model leads at 4 years was 99.5% (95% confidence interval, 99.0 to 99.9) compared with 99.9% (95% confidence interval, 99.6 to 100.0) of 3401-model leads (p=0.110). The cumulative occurrence rate of the 3501-model safety notification fracture was 0.1% (95% confidence interval, 0.0 to 0.3).

Conclusions

In this large multicenter analysis, the survival probability of model-3501 S-ICD leads was in line with that reported by the manufacturer, was not significantly lower than that of 3401-model leads (not affected by a safety notification), and still higher than that reported with transvenous leads. Although an enhanced electrode is now available, which addresses the potential for electrode body fracture, the present findings are reassuring and may have significant implications for the management of patients who have affected leads.

Temporal trend of QRS voltage amplitude on surface sensing in patients with arrhythmogenic cardiomyopathy implanted with a subcutaneous ICD

Funding Acknowledgements

Type of funding sources: None.

Introduction

Previous studies have reported a significant decrease in ventricular sensing amplitude during follow-up in patients with arrhythmogenic cardiomyopathy (ACM) implanted with trans-venous implantable cardioverter defibrillator (ICD). No data are yet available on sensing amplitudes values over time for subcutaneous ICD (S-ICD). Low QRS voltage on surface ECG is one of the diagnostic clues in ACM. This, together with the progressive nature of the disease and the not-negligible incidence of inappropriate shocks due to oversensing, raise safety concerns on the use of S-ICD in this population.

Aim

The aim of this study was to evaluate the trend of QRS amplitude on subcutaneous ECG (S-ECG) over time in patients with ACM implanted with S-ICD.

Methods

We conducted a retrospective analysis on a cohort of consecutive patients with ACM implanted with S-ICD in two tertiary centers, prospectively enrolled in the home-monitoring program. The S-ECGs recorded by the S-ICD at the time of first and last data transmission were analyzed. The voltage amplitude was estimated for each QRS complex available, and the values obtained were compared between the two time points (i.e. baseline and last follow-up available). The primary endpoint of our study was the proportion of patients in which the decrease of QRS amplitude during follow-up was statistically significant.

Results

Eleven patients (1 female, 9%) were enrolled in this study. The mean age was 43±10 years. An exclusive right ventricular involvement was reported in 5 patients (46%), 2 patients (18%) had an exclusive left ventricular, and 4 (36%) a biventricular involvement. Three patients (27%) were implanted in secondary prevention. During a median follow-up of 9 months (IQR 6-17), 6 patients (55%, 95%CI 24-84%) experienced a statistically significant reduction in the S-ECG QRS amplitude (Figure A). Considering these 6 patients, the mean absolute reduction was -0.46±0.32 mV corresponding to a relative reduction of -19%±11%. Moreover, we found a statistically significant correlation between follow-up duration and QRS amplitude relative reduction (r=-0.89, p=0.018, Figure B). No patients experienced inappropriate shocks.

Conclusions

In a cohort of ACM patients implanted with S-ICD the majority of patients experienced a significant reduction in the amplitude of QRS voltage during follow-up, confirming a potential safety concern on the use of S-ICD in this population. Further studies are needed to investigate this issue.

P27 MONOMORPHIC VENTRICULAR TACHYCARDIA INDUCED BY BLUNT CHEST TRAUMA IN A YOUNG MAN WITHOUT STRUCTURAL HEART DISEASE: A CASE REPORT

Introduction

Life–threatening ventricular arrhythmias secondary to chest trauma without structural cardiac damage (i.e. commotio cordis [CC]) are a rare but dramatic cause of sudden cardiac death. We present a case of fast ventricular tachycardia (VT) induced by blunt chest trauma in a healthy man during sports activity.

Case Presentation

A 22–year–old man, competitive soccer player, was admitted to our hospital for VT. A few hours before admission, after a heavy ball impact in the chest during a soccer match, he suddenly reported fast and regular palpitation with lightheadedness and dyspnea, without loss of consciousness. The emergency medical service was activated, and the evaluation revealed a hemodynamically tolerated monomorphic VT with a rate of almost 285 bpm (Fig.A). Amiodaron infusion was ineffective and sinus rhythm (SR) was restored by electrical cardioversion. At the time of admission, he was asymptomatic. Familiar history, past medical history and physical examination were unremarkable. ECG revealed regular SR, with minimal right bundle branch conduction delay (Fig.B). Blood samples showed normal blood cells count, electrolyte concentrations and liver, kidney, and thyroid function; seriate high sensitivity troponin I determinations were negative. Echocardiography and cardiac magnetic resonance showed normal findings. Computed tomography angiography excluded coronary anomalies. Exercise test revealed no signs of cardiac ischemia and no effort–induced arrhythmias. The fluoroscopy–free unipolar and bipolar voltage maps showed normal electrograms throughout the right ventricle (Fig.C). No sustained arrhythmias were induced by programmed ventricular stimulation. The patient was then discharged with the indication to cardiology follow–up and the advice to avoid contact sports activities.

Discussion

VT is a rare presentation of CC. It has been proposed that CC occurs when a chest strike timed at the upstroke of the T–wave causes both ventricular depolarization trigger and altered dispersion of repolarization, mainly via activation of KATP channels. In the absence of structural heart disease (SHD), the usual presenting rhythm is ventricular fibrillation and there are no accepted mechanisms to explain monomorphic VT in this context. Some authors reported monomorphic VT after chest trauma as the first manifestation of arrhythmogenic cardiomyopathy. Therefore, a careful follow–up will be needed to exclude future development of SHD in this patient.

P31 PERCUTANEOUS LEFT STELLATE GANGLION BLOCK AS PRE–TREATMENT STRATEGY FOR HIGH–RISK PATIENTS WHO ARE CANDIDATES FOR INVASIVE PROCEDURES POTENTIALLY ASSOCIATED WITH ADRENERGIC STIMULATION: AN HYPOTHESIS–GENERATING CASE REPORT

Introduction

Percutaneous left stellate ganglion block (PLSGB) has been reported as a safety and effective procedure for the management of refractory arrhythmic storm (AS). In this report we present a case of a man with refractory AS effectively treated with PLSGB, subsequently candidate for an invasive procedure potentially associated with adrenergic stimulation and propose the use of this technique as pre–treatment strategy in this clinical setting.

Case presentation

A 57–year–old man was admitted to our hospital for AS. Past medical history revealed that two years earlier he had been treated with primary percutaneous coronary intervention for ST–segment elevation myocardial infarction. Four months before admission he underwent coronary artery bypass graft surgery with concomitant mechanical mitral valve replacement, closure of an interventricular defect and, considering the severe left ventricular disfunction, he was implanted with an automatic defibrillator in primary prevention. At the time of admission, he was treated with lidocaine infusion with remission of arrhythmic events. Comprehensive diagnostic workup revealed no overt triggers for AS. Five days after admission, the patient experienced recurrence of ventricular arrhythmias (VA), refractory to amiodarone, lidocaine, and magnesium infusion, increased pacing rate, and sedation with dexmedetomidine. PLSGB was then attempted with the injection of lidocaine and ropivacaine using an anatomical approach with complete remission of arrhythmic events. After a week free from VAs, a new AS was observed and PLSGB was repeated using the same modality with complete arrhythmic resolution. Considering the advanced heart failure, the patient was candidate to heart transplantation (HT) and, before undergoing gastro– and colonoscopy required for inclusion in the HT program, with the aim to reduce the risk of VA recurrences triggered by potential adrenergic stimulation, we pre–treated the patient with PLSGB using only ropivacaine, with successful induction of temporary Horner syndrome (Fig. A). The endoscopy procedures were performed successfully with no VA events and the patient was then discharged waiting for HT.

Conclusion

We propose the use of PLSGB as a pre–treatment strategy for patients at high–risk of VAs who are candidates for invasive procedures potentially associated with adrenergic stimulation. This report could be hypotheses–generating for further studies on this topic.

P9 TEMPORAL TREND OF QRS VOLTAGE AMPLITUDE ON SURFACE SENSING IN PATIENTS WITH ARRHYTHMOGENIC CARDIOMYOPATHY IMPLANTED WITH A SUBCUTANEOUS ICD

Introduction

Previous studies have reported a significant decrease in ventricular sensing amplitude during follow–up in patients with arrhythmogenic cardiomyopathy (ACM) implanted with trans–venous implantable cardioverter defibrillator (ICD). No data are yet available on sensing amplitude values over time for subcutaneous ICD (S–ICD). Low QRS voltage on surface ECG is one of the diagnostic clues in ACM. This, together with the progressive nature of the disease and the not–negligible incidence of inappropriate shocks due to oversensing, raise safety concerns on the use of S–ICD in this population. The aim of this study was to evaluate the trend of QRS amplitude on subcutaneous ECG (S–ECG) over time in patients with ACM implanted with S–ICD.

Methods

We conducted a retrospective analysis on a cohort of consecutive patients with ACM implanted with S–ICD in two Italian tertiary centers, prospectively enrolled in the home–monitoring program. The S–ECGs recorded at the time of first and last data transmission were analyzed. The voltage amplitude was estimated for each QRS complex available, and the values obtained were compared between the two time points (i.e. baseline and last follow–up available). The primary endpoint of our study was the proportion of patients in which the decrease of QRS amplitude during follow–up was statistically significant.

Results

Eleven patients (1 female, 9%) were enrolled in this study. The mean age was 43±10 years. An exclusive right ventricular involvement was reported in 5 patients (46%), 2 patients (18%) had an exclusive left ventricular, and 4 (36%) a biventricular involvement. Three patients (27%) were implanted in secondary prevention. During a median follow–up of 9 months (IQR 6–17), 6 patients (55%, 95%CI 24–84%) experienced a statistically significant reduction in the S–ECG QRS amplitude (Fig. A). Considering these 6 patients, the mean absolute reduction was –0.46±0.32 mV corresponding to a relative reduction of –19%±11%. Moreover, we found a statistically significant correlation between follow–up duration and QRS amplitude relative reduction (r=–0.89, p = 0.018, Fig. B). No patients experienced inappropriate shocks.

Conclusions

In a cohort of ACM patients implanted with S–ICD the majority of patients experienced a significant reduction in the amplitude of QRS voltage during follow–up, confirming a potential safety concern on the use of S–ICD in this population. Further studies are needed to investigate this issue.

Wearable Cardioverter Defibrillator (WCD) in Italy: results from the nationwide multicenter registry WEAR-ITA

Funding Acknowledgements

Type of funding sources: None.

BACKGROUND

The Wearable Cardioverter Defibrillators (WCD) has been used extensively in Italy since 2015, following long years of experience in other countries. This technology provides temporary protection from Sudden Cardiac Death (SCD) for patients with an evolving risk profile that may not yet be eligible for an Implantable Cardioverter Defibrillator (ICD). Collecting national data on use of the device can help build a picture that will enable an understanding on how to use the WCD appropriately in the future.

PURPOSE

Our purpose has been to investigate WCD usage on a nationwide level. This is in terms of target population, average wear time, patient compliance, diagnosed and treated arrhythmic events and patient outcome once they stopped wearing the device.

METHODS

WEAR-ITA is a nationwide, multi-centre retrospective observational project. Patient data was retrospectively collected from the Italian hospitals that agreed to take part in the data collection for all patients fitted with a WCD between April 2015 to May 2018. All data refers to the range from the first day of wear until the end of use.

RESULTS

We collected data for 411 patients from 15 (75%) Italian regions. WCD use among the different regions was heterogeneous with a median of 0.5 (0.2-1.2) WCD wore/105 inhabitants. The mean age of the population was 55(±14) and the majority of patients were male (79%). Main WCD indication was non-ischemic cardiomyopathy with reduced ejection fraction (51%), ischemic etiology with severe systolic dysfunction (31%), uncertain or unidentified diagnosis (10%) that then revealed to be predominantly channelopathies or myocarditis and after ICD extraction (8%). Patients wore the WCD for a median of 59 (33-90) days and the median daily weartime was 23 (22,7-23,8) hours. In 15 patients (4%), the WCD recorded non sustained ventricular tachycardia (VT), 10  patients (2%) had hemodynamically well-tolerated sustained VT not needing a shock. 8 patients (2%) received effective appropriate shocks. Time to episodes were respectively 61 (14-61) days for non-sustained VT and 28 (19-70) days for VT/VF. 2 patients (0.5%) received inappropriate shocks for sinus tachycardia and atrial fibrillation (AF) respectively. WCD recorded new onset of supra ventricular tachycardia episodes in 12 patients (3%) and of atrial fibrillation (AF) in 7 patients (2%). 7 patients (2%) died while wearing WCD; none of them from SCD. At the end of the WCD use, 195 patients (47%) did not receive an ICD while 209 patients (51%)were implanted.

CONCLUSIONS

WCD is an effective therapy for the treatment of SCD with a very low complication rates. The indication and penetration in Italy is quite heterogeneous. The patient’s compliance is high over time. The incidence of appropriate shock is not negligible; only half of patients, who wore WCD, received an ICD. There is however still a requirement to conduct further randomized trials to understand which patients could most benefit from the use of WCD. Abstract Figure. Wereable Cardioverter Defibrillator

P524Serratus anterior plane block in subcutaneous implantable cardioverter defibrillator implantation: a case-control analysis

Funding Acknowledgements

No Funding

OnBehalf

RHYTHM DETECT study group

Background

A two-incision technique, in association with inter-muscular positioning of the subcutaneous defibrillator (S-ICD), is now the most frequently adopted implantation approach in Europe. Ultrasound-guided serratus anterior plane block (SAPB) has been proposed in order to provide anesthesia/analgesia during S-ICD implantation.

Objective

We performed a case-control analysis in which a standardized SAPB approach was compared with the typical local anesthesia and sedation approach.

Methods

91 consecutive patients underwent implantation of an S-ICD with the SAPB approach for anesthesia/analgesia at 10 centers. The control group consisted of 55 consecutive patients who underwent S-ICD implantation with standard local approach.

Results

The mean procedure duration was 59 ± 15min in the SAPB group and 76 ± 23min in the control group (p < 0.001). No operative complications were reported in either group. During the procedure, 79 (87%) patients in the SAPB group and 25 (46%) patients in the control group (p < 0.001) remained awake. Lower values of pain intensity at the device pocket (p = 0.005) and the lateral tunneling site (p = 0.046) were reported in the SAPB group. The difference in static (p = 0.002) and dynamic (p = 0.007) pain intensity between the groups persisted at 1 hour, while no differences were observed 6 hours after the end of the procedure.

Conclusions

SAPB is feasible and effective in providing anesthesia/analgesia during S-ICD implantation. The procedures were successfully accomplished and no complications occurred in either group. However, SAPB was associated with lower pain levels, enabling the need for sedation to be reduced and more patients to remain awake. Moreover, it resulted in shorter procedure durations.

The recombinant protein rSP03B is a valid antigen for screening dog exposure to Phlebotomus perniciosus across foci of canine leishmaniasis

The frequency of sandfly-host contacts can be measured by host antibody levels against sandfly salivary proteins. Recombinant salivary proteins are suggested to represent a valid replacement for salivary gland homogenate (SGH); however, it is necessary to prove that such antigens are recognized by antibodies against various populations of the same species. Phlebotomus perniciosus (Diptera: Psychodidae) is the main vector of Leishmania infantum (Trypanosomatida: Trypanosomatidae) in southwest Europe and is widespread from Portugal to Italy. In this study, sera were sampled from naturally exposed dogs from distant regions, including Campania (southern Italy), Umbria (central Italy) and the metropolitan Lisbon region (Portugal), where P. perniciosus is the unique or principal vector species. Sera were screened for anti-P. perniciosus antibodies using SGH and 43-kDa yellow-related recombinant protein (rSP03B). A robust correlation between antibodies recognizing SGH and rSP03B was detected in all regions, suggesting substantial antigenic cross-reactivity among different P. perniciosus populations. No significant differences in this relationship were detected between regions. Moreover, rSP03B and the native yellow-related protein were shown to share similar antigenic epitopes, as canine immunoglobulin G (IgG) binding to the native protein was inhibited by pre-incubation with the recombinant form. These findings suggest that rSP03B should be regarded as a universal marker of sandfly exposure throughout the geographical distribution of P. perniciosus.

Ongoing outbreak of visceral leishmaniasis in Bologna Province, Italy, November 2012 to May 2013

Binary file ES_Abstracts_Final_ECDC.txt matches

The burden of visceral leishmaniasis in Italy from 1982 to 2012: a retrospective analysis of the multi-annual epidemic that occurred from 1989 to 2009

Starting from 1989 Italy experienced an increase of visceral leishmaniasis (VL) cases over a baseline of 10 to 30 cases reported annually. The number of cases peaked in 2000 and 2004 with more than 200 cases/year, and subsequently declined to reach on average one third of the 2000 peak value in the period after 2010. A retrospective analysis from 1982 to 2012 showed that the multi-annual epidemic consisted of major components including (i) an outbreak involving infants and immunocompetent adults in parts of the Campania region (southern peninsular Italy) and that appears to have declined naturally, (ii) a second outbreak affecting human immunodeficiency virus (HIV)-infected individuals throughout the country, that declined owing to the use of highly active antiretroviral therapies (HAART), (iii) a generalised increase of VL cases in immunocompetent individuals and patients affected by associated conditions other than HIV from endemic regions of peninsular and insular Italy (other than Campania), which was due to a geographical spreading of VL foci, with no major case-clusters or outbreak features. A minor component consisted in the appearance of a few autochthonous cases in formerly non-endemic areas, starting from the early 1990s. Epidemic determinants and reasons for VL decline in the Campania region remain largely unexplained, despite the information available on canine reservoir and phlebotomine vectors in Italy.

Ongoing outbreak of visceral leishmaniasis in Bologna Province, Italy, November 2012 to May 2013

An increased number of autochthonous visceral leishmaniasis (VL) cases has recently been reported in Bologna Province in northern Italy. Over six months from November 2012 to May 2013, 14 cases occurred, whereas the average number of cases per year was 2.6 (range: 0-8) in 2008 to 2012. VL was diagnosed in a median of 40 days (range: 15-120) from disease onset. This delay in diagnosis shows the need for heightened awareness of clinicians for autochthonous VL in Europe.

The burden of visceral leishmaniasis in Italy from 1982 to 2012: a retrospective analysis of the multi-annual epidemic that occurred from 1989 to 2009

Starting from 1989 Italy experienced an increase of visceral leishmaniasis (VL) cases over a baseline of 10 to 30 cases reported annually. The number of cases peaked in 2000 and 2004 with more than 200 cases/year, and subsequently declined to reach on average one third of the 2000 peak value in the period after 2010. A retrospective analysis from 1982 to 2012 showed that the multi-annual epidemic consisted of major components including (i) an outbreak involving infants and immunocompetent adults in parts of the Campania region (southern peninsular Italy) and that appears to have declined naturally, (ii) a second outbreak affecting human immunodeficiency virus (HIV)-infected individuals throughout the country, that declined owing to the use of highly active antiretroviral therapies (HAART), (iii) a generalised increase of VL cases in immunocompetent individuals and patients affected by associated conditions other than HIV from endemic regions of peninsular and insular Italy (other than Campania), which was due to a geographical spreading of VL foci, with no major case-clusters or outbreak features. A minor component consisted in the appearance of a few autochthonous cases in formerly non-endemic areas, starting from the early 1990s. Epidemic determinants and reasons for VL decline in the Campania region remain largely unexplained, despite the information available on canine reservoir and phlebotomine vectors in Italy.

Clinical features of cardio-renal syndrome in a cohort of consecutive patients admitted to an internal medicine ward

Introduction:

Cardiorenal syndrome (CRS) is a disorder of the heart and kidney whereby interactions between the 2 organs can occur. We recorded the clinical features of CRS in patients consecutively admitted to an Internal Medicine ward.

Patients and Methods:

We retrospectively analyzed the anthropometric, history, clinical, biochemical and treatment characteristics in 438 out of 2,998 subjects (14.6%) admitted to our unit (from June 2007 to December 2009), diagnosed with CRS, according to Acute Dialysis Quality Initiative (ADQI) recommendations. Estimated glomerular filtration (eGFR) was calculated using several equations: MDRD (Modification of Diet in Renal Disease; 2 variations GFR_MDRD186, GFR_MDRD175), Mayo, Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and Cockroft-Gault.

Results:

Mean age was 80±8 years, 222 (50.6%) were males, 321 (73.2%) were smokers, 229 (52.2%) were diabetic, 207 (47.2%) had a history of acute myocardial infarction, 167 (38.1%) had angina, 135 (30.8%) were affected by cerebrovascular disease, 339 (77.3%) had peripheral arterial disease. CRS was type 1 in 211 cases (48.2%), type 2 in 96 (21.9%), type 3 in 88 (20.1%), type 4 in 29 (6.6%) and type 5 in 14 (3.2%). eGFR, calculated by different formulae, ranged between 31 and 36 ml/min/1.73 m². GFR was lower in CRS type 3 than in the other types, and the values ranged between 24 and 27 ml/min/1.73 m². Mean hospital length-of-stay (LOS) was 9.8±6.3 days. Diuretics were the most prescribed medication (78.7%); only 5 patients underwent haemodialysis.

Conclusions:

CRS is common, especially in the elderly. CRS Type 1 was the prevalent subset and patients had stage 3-4 renal insufficiency. Results obtained from the GFR equations were similar although the Mayo equation tended to overestimate the eGFR.

Randomized, double-blind comparison of effects of abiciximab bolus only vs. on-label regimen on ex vivo inhibition of platelet aggregation in responders to clopidogrel undergoing coronary stenting

BACKGROUND

On top of aspirin, an abciximab bolus-only regimen results in a 30% drop in platelet inhibition at 6 h as compared with the on-label regimen. The concomitant administration of high loading dose clopidogrel, by bridging with abciximab bolus, may sustain suppression of platelet activity over time.

OBJECTIVES

To investigate the non-inferiority of abciximab bolus-only and concomitant high loading dose clopidogrel vs. abciximab bolus + infusion with respect to the inhibition of platelet aggregation (IPA) as determined by light transmission aggregometry.

PATIENTS/METHODS

Seventy-three patients with non-ST segment elevation acute coronary syndromes underwent double-blind randomization to abciximab bolus followed by a 12-h placebo infusion and concomitant 600-mg clopidogrel vs. abciximab bolus + a 12-h infusion and 300 mg of clopidogrel. IPA was determined by light transmission aggregometry throughout 24 h. Clopidogrel poor responsiveness was defined as ≥ 50% 5 μmol L⁻¹ ADP-induced maximum platelet aggregation.

RESULTS

In clopidogrel responders (n = 68), IPA after 20 μmol L⁻¹ ADP at 4 h was 89% ± 13% in the bolus-only arm vs. 92% ± 14% in the bolus + infusion arm (P = 0.011 for non-inferiority). IPA after 5 or 20 μmol L⁻¹ ADP and 5 or 15 μmol L⁻¹ TRAP and the proportion of patients showing ≥ 80% IPA did not differ at any time point, irrespective of clopidogrel responsiveness status. Thirty-day outcomes were similar, whereas hemoglobin (0.91 ± 0.8 vs. 0.5 ± 0.7 g dL⁻¹ ; P = 0.01) and platelet count mean drop (41.7 ± 57 vs. 18.6 ± 34 10⁹ L⁻¹; P = 0.042) were significantly reduced in the bolus-only arm.

CONCLUSIONS

Withholding abciximab post-bolus infusion in patients receiving high loading dose clopidogrel does not impair platelet inhibition throughout 24 h, and has the potential to improve the safety profile of the drug at reduced costs.

Development of recombinant chimeric antigen expressing immunodominant B epitopes of Leishmania infantum for serodiagnosis of visceral leishmaniasis

Wild canids and domestic dogs are the main reservoir of zoonotic visceral leishmaniasis (VL) caused by Leishmania infantum (syn.: Leishmania chagasi). Serological diagnosis of VL is therefore important in both human and dog leishmaniasis from a clinical and epidemiological point of view. Routine diagnosis of VL is traditionally carried out by immunofluorescent antibody test (IFAT), which is laborious and difficult to standardize and to interpret. In the last decade, however, several specific antigens of Leishmania infantum have been characterized, allowing the development of a recombinant-based immunoassay. Among them, the whole open reading frame encoding K9 antigen, the gene fragment encoding the repetitive sequence of K26, and the 3'-terminal gene fragment of the kinesin-related protein (K39sub) were previously evaluated as diagnostic markers for canine leishmaniasis and proved to be independent in their antibody reactivity. Since sensitivity of serological test is usually higher in multiple-epitope format, in this study the relevant epitopes of K9, K26, and K39 antigens were joined by PCR strategy to produce the chimeric recombinant protein. The resulting mosaic antigen was found highly expressed in Escherichia coli and efficiently purified by affinity chromatography. Antigenic properties of this recombinant antigen were evaluated by indirect enzyme-linked immunosorbent assay (ELISA) using a panel of human and dog sera previously characterized by parasitological and/or serological techniques. Chimeric ELISA showed 99% specificity in both human (n = 180) and canine (n = 343) control groups, while sensitivity was higher in canine VL (96%, n = 213) than in human VL (82%, n = 185). Accordingly, concordance between IFAT and canine chimeric ELISA (k = 0.95, 95% confidence interval = 0.93 to 0.98) was higher than between IFAT and human chimeric ELISA (k = 0.81, 95% confidence interval = 0.76 to 0.87). Results suggest the potential use of this new antigen for routine serodiagnosis of VL in both human and canine hosts.

Failure of a multi-subunit recombinant leishmanial vaccine (MML) to protect dogs from Leishmania infantum infection and to prevent disease progression in infected animals

We report results of a Phase III trial of the multi-subunit recombinant Leishmania polyprotein MML for the protection of dogs against infection by Leishmania infantum. The antigen, also known as Leish-111f, is the first antileishmanial human vaccine entered Phase I clinical testing. The study was performed in a leishmaniasis endemic area of southern Italy. Three groups of 15 Leishmania-free beagle dogs each, received 3 monthly injections with vaccines A (MML+MPL-SE adjuvant), B (sterile saline = control) and C (MML+Adjuprime adjuvant), respectively, before transmission season 2002. The surviving dogs received a second three-dose vaccine course 1 year later. The dogs were naturally exposed to sandfly bites for 2.5 months in 2002, and for 5 months in 2003. Every 2 months post vaccination, dogs were examined by clinical and immunological evaluation, and by specific serology, microscopy, culture and PCR. A weak lymphoproliferative response to MML was seen in A and C groups throughout the study period. One year after the first vaccine course, the cumulative incidence of leishmanial infections was 40% in group A, 43% in group B and 36% in group C. Two-year post-vaccination (1 year after the second vaccine course) the cumulative incidence was 87% in group A (with three symptomatic cases), 100% in group B (with no symptomatic cases) and 100% in group C (with two symptomatic cases). The efficacy of the MML vaccine as an immunotherapeutic agent for the prevention of disease progression (subpatent infection-->asymptomatic patent infection-->symptomatic patent infection) was evaluated through follow-up of dogs found infected prior to the second vaccination. Among 15 infected animals, progression to a subsequent stage of infection was found in 5/6 dogs of group A, 3/6 of group B and 2/3 of group C. We conclude that vaccination with MML is not effective to prevent leishmaniasis infection and disease progression in dogs under field conditions.

[Infantile visceral leishmaniasis in the Campania region, Italy: experience from a Paediatric Referral Centre]

In the first half of the 20th century, visceral leishmaniasis (VL) was a common infantile syndrome in coastal territories of the Campania region of Italy. After World War II, the incidence dropped to a few cases/year for three decades; in late 1980s the disease reemerged among both children and adults. To face the VL recrudescence, a Paediatric Reference Centre was established at the Santobono-Pausilipon hospital in Naples, for the clinical diagnosis, care and drug treatment of all infantile VL cases occurred in the Campania region. Rapid laboratory diagnosis was secured by a Diagnostic Reference Centre established at the Istituto Superiore di Sanità. Here, we report on the epidemiological and parasitological features of all cases referred to the Centre in the past 15 years. From 1990 to March 2004, a total of 255 cases were diagnosed and treated at the Centre. The Figure shows the yearly trend of patients (min. 3 cases in 1990 and 1991, max. 30 cases in 2000). There were 135 males (52.9%); the age ranged 4 months-14 years, but 189 patients (74.1%) were < or = 3 years old. The majority of the patients (189, 74.1%) were from the Naples province, with a cluster of 102 cases (40% of total patients) from the towns and districts surrounding Vesuvius. Twenty-seven cases (10.6%) were from the town of Maddaloni, Caserta province, whereas 15 cases (5.9%) were from coastal villages of the Salerno province. Only 1 and 2 cases were from Benevento and Avellino provinces, respectively. All patients but seven, who have been treated with antimonial drugs in the 1990-1993 period, were successfully treated with a liposomal amphotericin B regimen. From bone-marrow aspirate samples, 138 Leishmania cultures were obtained in EMTM and Sloppy Evans' media, of which 134 have been typed by the electrophoretic analysis of 13 isoenzymes. Two zymodemes (Z) of L. infantum were routinely identified over the study period, ZMON-1 (the commonest zymodeme in the Mediterranean area) and ZMON-72, variant from MON-1 in PGM mobility and detected only in our region. The latter, identified in 61 patients (45.5%), was found exclusively distributed in towns of the Vesuvius area and in Maddaloni until 1996, but in recent years it appears to have spread to other areas of the Naples (including the island of Ischia) and Caserta provinces, but not to Salerno province. In conclusion, the VL macrofocus of the Naples-Caserta area is probably responsible for the highest number of infantile cases among any VL macrofoci described in southern Europe. Considering the limited efforts paid to control the canine reservoir, rapid diagnosis and appropriate treatment of patients still remain the first-line control measures aimed at reducing the health impact of the disease.

[Change in human visceral leishmaniasis treatment in Italy: retrospective study of 630 patients]

Since the 1940s meglumine antimoniate (MA) has been the only first-line drug for visceral leishmaniasis (VL) treatment in Italy. From 1991 through 1994, several patients of all ages, representing 1/3 of all immunocompetent VL patients reported during that period, were enrolled in clinical trials of liposomal amphotericin B (L-AmB), which led to a novel, safe, short course of VL treatment as an alternative to MA. In the same period, other lipid-associated AmB drugs were registered in Italy for the treatment of fungal infections, i.e., AmB colloidal dispersion (ABCD) and AmB lipid complex (ABLC). A retrospective analysis was performed on data collected at the Unit of Protozoology of Istituto Superiore di Sanità, Rome, to assess whether changes have occurred in first-line drug regimens adopted in Italy for routine VL treatment, during the 1995-2002 period. The sample consisted of immunocompetent individuals clinically suspected for VL, in whom the disease was confirmed by the examination of serum and bone marrow specimens sent to the Unit by hospitals from throughout the country. Relevant information on patients was then recorded, which included drug regimens used and post-therapy results. We recorded treatment information for 630 patients, representing a large proportion (55.5%) of 1,135 immunocompetent individuals with VL reported in Italy from 1995 through 2002. About half were children (306). Every year, patients were referred by 19 to 42 hospitals, with a range of 1 to 30 patients per hospital. MA was the first-line drug used in 159 patients (25.2%). However, the proportion of MA-treated patients has steadily decreased from 55.9% in 1995 to 1.0% in 2002. We recorded the failure of MA therapy in 16 patients (10.1%), who were successfully retreated with a L-AmB regimen. The rate of MA failures significantly increased in recent years, from 5.3% in 1995 to 36.4% in 2000 (p = 0.01). AmB drugs have been the only alternative drugs used in the remaining 471 patients (74.8%). L-AmB accounted for most regimens (441, 93.6%). The proportion of patients treated with any AmB-based drugs increased from 44.1% in 1995 to 99.0% in 2002. Drug treatment was unsuccessful in 15 patients (3.2%), who were successfully retreated with a high-dose L-AmB regimen. This rate was significantly lower than the MA failure rate (p = 0.001). Results have shown a countrywide change in therapy over the period considered. A traditionally effective, but moderately toxic drug (MA) has been almost fully replaced by a new compound (L-AmB) with negligible toxicity, in an epidemiologic context of disease reemergence. Furthermore, short courses of 6 to 7 days, as required for lipid-associated AmB, are highly cost-effective if compared with 21- to 28-day courses needed for standard MA treatment.

Evaluation of the Leishmania recombinant K39 antigen as a diagnostic marker for canine leishmaniasis and validation of a standardized enzyme-linked immunosorbent assay

Canine infections with Leishmania infantum are important as a cause of serious disease in the dog and as a reservoir for human visceral leishmaniasis (VL). Accurate diagnosis of canine infections is essential to the veterinary community and for VL surveillance programs. A standardized ELISA using a purified recombinant antigen (rK39) specific to VL was compared to the immunofluorescent antibody test (IFAT) as the standard. The ELISA was developed, optimized and evaluated using sera from 6368 dogs. The standardized ELISA and IFAT results were highly concordant. The timing and pattern of ELISA and IFAT seroconversion in dogs followed prospectively after natural infections were very similar. Antibodies reacting with rK39 were more common in asymptomatic canine infections than reported for subclinical human VL. The rK39 ELISA is a relatively simple and rapid assay for assessing the infection status of dogs, and is an alternative to IFAT, especially when screening large numbers of samples.

Efficacy of amphotericin B colloidal dispersion in the treatment of Mediterranean visceral leishmaniasis in immunocompetent adult patients

Twelve immunocompetent adults with Mediterranean visceral leishmaniasis (VL) were treated with amphotericin B colloidal dispersion (ABCD; 2 mg/kg/d for 7 d). All patients showed rapid clinical response without significant adverse events. Two weeks after therapy they were parasitologically cured and no relapses occurred during 6 months. ABCD is a valid alternative in the management of Mediterranean VL in adult patients.

[Prognostic systems in intensive care: TRISS, SAPS II, APACHE III]

BACKGROUND

To validate the accuracy of SAPS II, APACHE III and TRISS for the prediction of mortality in Intensive Care Unit (ICU) at polytrauma patients admission. The outcome of multiple trauma patients is often linked to the degree of physiologic dysfunction and to the extension of anatomic lesions, the age of the patient and the lesion mechanism.

METHODS

The study population consisted of 93 cases of multiple injured patients hospitalised at the ICU of the Padua hospital from October 1998 to October 1999; the term polytraumatized patient is referred to patients who have multiple lesions of which at least one potentially endangers, immediately or in a short term, their life. These cases were evaluated with the APACHE III, SAPS II, Revised Trauma Score and Injury Severity Score. The predictive power of each system was evaluated by using decision matrix analysis to compare observed and predicted outcome with a decision criterion of 0.50 and 0.40 for risk of hospital death.

RESULTS

All trauma score systems under study showed high accuracy rates, above all if they are used with a 40% positive test.

CONCLUSIONS

The prognostic scales used in this study showed a good correlation between expected and observed cases, particularly with TRISS and APACHE III systems. The APACHE III system seems to be the most reliable of the different methods analysed. These prognostic systems are seldom or occasionally used in the ICU, in Padua and in the whole of Italy, so Italian data are not suitable to be compared to international ones. Due to urgency, the importance of the evaluation scales is often underestimated, but even if they require time and attention, they surely can be useful in the evaluation of the treatment, and not only of a polytraumatized patient.

NO donors inhibit Leishmania infantum cysteine proteinase activity

Nitric oxide (NO) releasing drugs (e.g., glyceryl trinitrate) were successfully used in the treatment of cutaneous leishmaniasis in man. In the present study, the effect of NO donors on the catalytic activity of the cysteine proteinase from promastigotes of Leishmania infantum, an agent of Old World visceral and cutaneous leishmaniases, is reported. In particular, one equivalent of NO, released by the NO donors S-nitrosoglutathione, glyceryl trinitrate, (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide, 3-morpholinosydnonimine, S-nitrosoacetylpenicillamine and sodium nitroprusside, inhibited one equivalent of the parasite cysteine proteinase. As expected, NO-deprived compounds did not affect the catalytic activity of the parasite cysteine proteinase. Furthermore, the absorption spectrum of the (+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide-treated inactive L. infantum enzyme displayed a maximum in the 330-350 nm wavelength range. The reducing agents dithiothreitol and L-ascorbic acid completely prevented parasite cysteine proteinase inhibition by NO, fully restored the catalytic activity, and reversed the NO-induced absorption spectrum of the inactive enzyme. Moreover, S-nitrosoacetylpenicillamine displayed a leishmanicidal effect, inhibiting the cysteine proteinase activity in vivo. As expected, the NO-deprived compound N-acetylpenicillamine did not affect significantly the parasite viability and the enzyme activity in vivo. These data suggest that the L. infantum cysteine proteinase undergoes NO-mediated S-nitrosylation, thereby representing a possible mechanism of antiparasitic host defence.

Early suppression of lymphoproliferative response in dogs with natural infection by Leishmania infantum

Dogs are the domestic reservoirs of zoonotic visceral leishmaniasis caused by Leishmania infantum. Early detection of canine infections evolving to clinically patent disease may be important to leishmaniasis control. In this study we firstly investigated the peripheral blood mononuclear cell (PBMC) response to leishmanial antigens and to polyclonal activators concanavalin A, phytohemagglutinin and pokeweed mitogen, of mixed-breed dogs with natural L. infantum infection, either in presymptomatic or in patent disease condition, compared to healthy animals. Leishmania antigens did not induce a clear proliferative response in any of the animals examined. Furthermore, mitogen-induced lymphocyte proliferation was found strongly reduced not only in symptomatic, but also in presymptomatic dogs suggesting that the cell-mediated immunity is suppressed in progressive canine leishmaniasis. To test this finding, naive Beagle dogs were exposed to natural L. infantum infection in a highly endemic area of southern Italy. Two to 10 months after exposure all dogs were found to be infected by Leishmania, and on month 2 of exposure they all showed a significant reduction in PBMC activation by mitogens. Our results indicate that suppression of the lymphoproliferative response is a common occurrence in dogs already at the beginning of an established leishmanial infection.

A cloned antigen (recombinant K39) of Leishmania chagasi diagnostic for visceral leishmaniasis in human immunodeficiency virus type 1 patients and a prognostic indicator for monitoring patients undergoing drug therapy

Serologic assays using crude antigens for the diagnosis of visceral leishmaniasis in human immunodeficiency virus type 1 (HIV)-seropositive patients have been shown to lack sensitivity and specificity, particularly in AIDS patients. Antibodies to a cloned antigen, recombinant (r) K39, of Leishmania chagasi are specific for members of the Leishmania donovani complex and have been shown to indicate active disease in immunocompetent persons. This study demonstrated that antibodies to rK39 were also detectable in HIV-seropositive patients coinfected with Leishmania infantum. Furthermore, the rK39 ELISA was more sensitive than an IFA for detecting L. infantum infections in patients with AIDS. In addition, antibody titers to rK39 in HIV-negative patients infected with L. infantum or L. chagasi declined during treatment with meglumine antimoniate or liposomal amphotericin B. In contrast, most patients who clinically relapsed showed increased antibody titers to rK39. These data demonstrate the diagnostic and prognostic utility of rK39 in detecting active visceral leishmaniasis.

Comparative efficacy of meglumine antimoniate and aminosidine sulphate, alone or in combination, in canine leishmaniasis

Thirty-two domestic dogs naturally infected with Leishmania infantum and showing viscero-cutaneous signs of canine leishmaniasis were treated with aminosidine sulphate (11 dogs) meglumine antimoniate (10 dogs) or with a combination of the two drugs (11 dogs) for 21 consecutive days. Clinical and laboratory assessments, made on day 21 and at 2, 4 and 6 months after initiation of treatment, showed that the drug combination gave the best score in terms of clinical efficacy, incidences of early clinical relapse, any clinical relapse or apparent parasitological cure, and reduction in parasite densities in bone-marrow and lymphnode aspirates (even though a lower dose of antimonial was used in the combination than for antimonial monotherapy). For each of the above parameters, however, the higher efficacy of the drug combination was not statistically significant, probably because of the large variations caused by using naturally infected animals of various ages and breeds.

Diffuse necrotic hepatic lesions due to visceral leishmaniasis in AIDS

A rare case of an AIDS patient who developed scattered necrotic involvement of the liver caused by Leishmania infantum is described. Of interest, marked splenomegaly, hypergammaglobulinemia and serum anti-Leishmania antibodies were absent and an incomplete response to therapy was observed. Diagnosis of visceral leishmaniasis (VL) was achieved by the demonstration of numerous amastigotes in both hepatocytes and macrophages on liver biopsy. Hepatic necrotic lesions, which when extensive could lead to acute hepatic failure, possibly reflect an atypical manifestation of liver involvement caused by L. infantum and depend on the immunological impairment which characterizes AIDS patients, thus preventing the formation of granulomas. Our observation confirms that VL can manifest atypical aspects in HIV-positive patients depending on the degree of the immunodeficiency. The frequency and severity of this pathology accounts for the need to list VL among AIDS-defining conditions.

A retrospective clinical study of canine leishmaniasis in 150 dogs naturally infected by Leishmania infantum

The clinical and laboratory findings observed in 150 dogs naturally infected by Leishmania infantum, from a large endemic area of southern Italy, are described. There was a gradual onset of clinical signs and the course of the disease was progressive in almost all the cases. The majority of the dogs were mongrels (43.3 per cent), male (64.7 per cent), of medium size (50.6 per cent), three to seven years old (64.7 per cent), and living outdoors (60 per cent). They showed generalised (56.7 per cent) or symmetrical (32 per cent) lymphadenomegaly; the mucous membranes of 87 of the dogs (58 per cent) were pale and moderate or severe splenomegaly was diagnosed in 80 dogs (53.3 per cent); weight loss was observed in 32 per cent of the animals. Skin abnormalities were very common, and included dry exfoliative dermatitis (56 per cent), ulcers (40 per cent) periorbital alopecia ('lunettes') (18 per cent), diffuse alopecia (14 per cent) and onychogryphosis (24 per cent). Ocular signs were observed in 24 dogs (16 per cent) including 16 cases of keratoconjunctivitis (three with keratoconjunctivitis sicca), six cases of moderate uveitis and two cases of panophthalmitis. The acute form of the disease was diagnosed in only six dogs and was characterised by fever and generalised lymphadenomegaly, and by the absence of skin lesions. Another six dogs had severe renal failure without systemic clinical signs of leishmaniasis. The most important laboratory findings were a severe or moderate increase in gammaglobulins, hypoalbuminaemia, hyperproteinemia and anaemia. Cultures or cytology tests for L infantum parasites were positive in 134 of the dogs. Following the standard procedures developed for human lymph node and bone marrow cytology tests, the leishmania density in the dogs varied from 1+ to 2+. Leishmania antibody titres were high (> 1:160) in almost all the dogs. Immunological tests for autoantibodies were positive in 25 of 53 dogs tested in the antinuclear antibody (ANA) test, in 15 of 43 dogs tested in the latex test and in five of 24 dogs tested in the Coombs test.

Epidemiologic surveillance of visceral leishmaniasis in Sicily, Italy

Visceral leishmaniasis (VL) is endemic in Sicily. Although it is a notifiable disease, there is evidence that the actual number of cases is higher than that reported. In 1987, a regional reference center for active surveillance of VL was established and it recorded a total of 284 cases through 1995, a mean of 31.5 cases/year and about four-fold more than previously reported. Of the 284 cases, 150 (53%) were children (< or = 14 years of age), and of the 134 adults, 39 (29%) were coinfected with human immunodeficiency virus (HIV). The commonest viscerotropic zymodeme of Leishmania infantum, MON 1, was identified in 40 (93%) of 43 HIV-negative and eight (57%) of 14 HIV-positive patients. Among 280 patients evaluated (i.e., all HIV-negative and 35 of 39 HIV-positive subjects), 254 (91%) were treated with meglumine antimoniate alone or in combination with other drugs; 23 (8%) received allopurinol or amphotericin B, either conventional or in liposomal form; and three terminally ill patients were not treated. Among the 245 HIV-negative patients, 236 (96%) were successfully cured, while nine (4%) (seven adults) died during the course of antimonial treatment. None of the 35 HIV-positive patients was definitively cured, although mortality was apparently associated with other opportunistic infections.

Epidemiological surveillance of leishmaniasis in HIV-1-infected individuals in Italy

OBJECTIVE

To actively detect leishmaniasis in HIV-1-infected individuals in Italy, to describe the epidemiological features of the disease in these patients, and to compare them with epidemiological features of leishmaniasis in HIV-negative patients.

DESIGN

Retrospective and prospective surveillance study.

PATIENTS

Italian patients with HIV-1 infection and leishmaniasis diagnosed between 1985 and 1994.

RESULTS

We recorded 116 leishmaniasis cases (115 visceral leishmaniasis), of which 94 (81%) were diagnosed over the last 4 years. Seventy-eight patients (67%) fulfilled the 1993 Centers for Disease Control and Prevention AIDS criteria. Leishmaniasis was passively reported in only 18% of cases. Leishmania incidence estimated among approximately 2700 AIDS patients living in leishmaniasis endemic areas averaged 1.6%, with a maximum of 4.9% in Sicily. These rates were up to 500-fold higher than among HIV-negative individuals living in the same areas, and were similar to those of ubiquitous opportunistic agents indicative of AIDS condition. Data from two major endemic regions indicated that overlap of HIV-1 and Leishmania infections has focal characteristics. The occurrence of small case clusters would suggest occasional modes of Leishmania transmission different from the insect vector. The isoenzyme characterization of 38 Leishmania stocks showed a zymodeme spectrum qualitatively and quantitatively different from that of the parasitic agent of visceral leishmaniasis in HIV-negative adults.

CONCLUSIONS

Active surveillance provided reliable evaluation on the occurrence of HIV-Leishmania coinfections in Italy, although it was limited to hospital-based cases in this study due to general under-reporting of cases. Biological and epidemiological spectrum of the disease suggests that visceral leishmaniasis should be included among AIDS-defining pathologies.

Gastric localization of Leishmania in a patient with acquired immunodeficiency syndrome. A case report

We report a case of gastric localization of Leishmania in a 29-year old man affected by AIDS. Gastric biopsies revealed macrophages infected with intracytoplasmic organisms attributable to Leishmania amastigotes. The authors emphasize the importance of performing random biopsies in the absence of endoscopic abnormalities.

Mediterranean visceral leishmaniasis in pregnancy

Visceral leishmaniasis (VL) in pregnancy is rare in Mediterranean countries. We report here 2 cases of VL in pregnant women who acquired the infection in Italy. In the first case, the disease was diagnosed and treated with liposomal amphotericin B during the pregnancy. In the second case, diagnosis was established and treatment with meglumine antimoniate both undertaken shortly after delivery. The 2 infants were followed clinically and serologically for 8-9 months after birth, but no evidence of congenital VL was observed.

HIV-Leishmania co-infections in Italy: serological data as an indication of the sequence of acquisition of the two infections

Twenty-two sera from visceral leishmaniasis (VL) patients with human immunodeficiency virus (HIV) infection (50% with the acquired immune deficiency syndrome) were examined for anti-Leishmania immunoglobulin G (IgG) antibodies and compared with 35 sera from VL patients without HIV (controls). Significant titres of specific IgG were found in 81.8% of co-infections. However, while control sera showed a restricted range of anti-Leishmania IgG titres, sera from co-infection cases displayed a considerable degree of variability, both quantitative and qualitative. They were clearly divided into 2 groups: one (18 sera) showing a continuous grading from nil to mid-concentrations of specific antibodies, the other (3 sera) showing titres 30-fold higher than this range. Taking into account the major immunological abnormalities involving humoral response described in HIV patient, the 2 groups may reflect a different sequence of acquisition of the 2 infective agents; the former representing VL acquired after HIV infection, and the latter representing the contrary situation.