Five waves of COVID-19 pandemic in Italy: results of a national survey evaluating the impact on activities related to arrhythmias, pacing, and electrophysiology promoted by AIAC (Italian Association of Arrhythmology and Cardiac Pacing)

BACKGROUND

The subsequent waves of the COVID-19 pandemic in Italy had a major impact on cardiac care.

METHODS

A survey to evaluate the dynamic changes in arrhythmia care during the first five waves of COVID-19 in Italy (first: March-May 2020; second: October 2020-January 2021; third: February-May 2021; fourth: June-October 2021; fifth: November 2021-February 2022) was launched.

RESULTS

A total of 127 physicians from arrhythmia centers (34% of Italian centers) took part in the survey. As compared to 2019, a reduction in 40% of elective pacemaker (PM), defibrillators (ICD), and cardiac resynchronization devices (CRT) implantations, with a 70% reduction for ablations, was reported during the first wave, with a progressive and gradual return to pre-pandemic volumes, generally during the third-fourth waves, slower for ablations. For emergency procedures (PM, ICD, CRT, and ablations), recovery from the initial 10% decline occurred in most cases during the second wave, with some variability. However, acute care for atrial fibrillation, electrical cardioversions, and evaluations for syncope showed a prolonged reduction of activity. The number of patients with devices which started remote monitoring increased by 40% during the first wave, but then the adoption of remote monitoring declined.

CONCLUSIONS

The dramatic and profound derangement in arrhythmia management that characterized the first wave of the COVID-19 pandemic was followed by a progressive return to the volume of activities of the pre-pandemic periods, even if with different temporal dynamics and some heterogeneity. Remote monitoring was largely implemented during the first wave, but full implementation is needed.

Conduction system pacing with Selectra 3D Sheath: Technical Results

Funding Acknowledgements

Type of funding sources: None.

Background

Conduction system pacing (CSP) allows physiological electrical activation. The Selectra3D sheath is a new tool able to guide the lead implantation on the His Bundle (HBP) or on the left bundle branch (LBBP). It does exist in 3 different shapes (40-S, 55-M, 65-L).

Objective

To evaluate the effectiveness of different Selectra3D introducers for CSP, considering the procedural success, stability of electrical parameters or need for implant revision at medium-term follow-up.

Methods and results

Selectra3D was used in 113 CSP procedures between Nov 2019 and Nov 2021. Mean patients age was 80±6 years, 54% males. Pacing indications were: AV block 52.2%, slow AF 12.4%; SND 12.4%, ablate&pace 5.3%, implant revision 0.9%, cardiomyopathy 16.8%. Mean EF was 40±15%. Single chamber PM was implanted in 4.8% pts, dual chamber PM in 57.1% pts while 26.2% and 11.9% pts received CRT-P and CRT-D devices respectively. Stylet-driven lead was used in 75 pts, fixed screw lead in 38 pts. HBP was obtained in 34% pts, LBBP in 55% pts, HBP+LBBP in 3% pts, while 8% cases were CSP implant failure (7 lead implanted in the septum; 2 in the coronary sinus). Selectra3D was the first delivery used during the procedure in 88% of cases (55-M in 76%; 40-S in 9%; 65-L in 3%), while was the second tool (after failure of the first delivery utilised) in the other pts. The first Selectra3D utilized during each implant was able to complete the procedure in 64% of cases, while in the other pts a second different tool was required to complete the implant. The Selectra3D 55-M was the mostly used and was able to reach the final position in most cases. In dilated atria the 65-L curve was preferred, while when the target point was more proximal the 45-S curve was the best choice. The baseline QRS duration was 135 ± 34 ms and the paced QRS duration was 113 ± 18 ms (P 0.003). The electrical parameters were optimal with sensing 8.7 ± 8 mV; impedance 562 ± 133 ohm; threshold 0.97 ± 0.47 V. During a median follow-up of 178 [34-402] days, 7 lead dislodgement (3 HBP and 4 LBBP) were recorded. All the others showed stability of the electrical parameters.

Conclusion

The Selectra3D introducers effectively supports CSP ensuring procedural success rate>90%. The 55-M curve fits for most of the anatomies, the 45-S curve allows to reach more proximal target, the 65-L curve more distal target in dilated atria. The electrical parameters were optimal at implant and remained stable during follow-up. 6% lead dislodgement were recorded.

Left Bundle Branch Pacing: procedural outcomes using different sheaths

Funding Acknowledgements

Type of funding sources: None.

Background

Left Bundle Branch Pacing (LBBP) ensures physiologic ventricular activation. Growing experiences are rising on its applicability . Different tools available allow successful implant in different cardiac anatomies.

Objective

To analyse implant success rate and acute electrical parameters in LBBP guided by C315 fixed curve sheath or Selectra3D sheath.

Methods

151 patients (mean age 79.8±8.3 years; 51% males) received LBBP. Pacing indication: AV block 50%, SND 12%, slow AF12%, ablate&pace 9%; HF 14%, revision of previous lead 1%. Coronary disease was present in 31%; hypertension in 93%, diabetes in 30%, severe valvular disease in 5%, persistent AF in 31% pts. Average QRS duration was 136±34 ms. Basal mean EF 52±12%. Different criteria for successful LBBP were analyzed (table 1).

Results

The lead was successfully implanted in the left bundle in 97.3% pts. In 60.5% pts guided by the C315 Medtronic fixed curve sheath while in 39.5% pts by the Selectra3D (40-S, 55-M, 65-L) Biotronik sheaths. 93 (63%) pts received 3830 fixed screw lead, 51 (35%) pts received Solia S 60 stylet-driven lead and 3 (2%) patients received Tendril 58 cm stylet-driven lead. All different criteria analysed to define successful LBBP were comparable in the C315 and Selectra 3D group (table 1). In 61% pts LBBP was the first choice, in 39% LBBP was aimed after unsatisfactory HBP (His threshold>2V or paced QRS>140 ms). The LBBP lead was connected to the RV port in 67% DR and 18% SR PMs; to the LV port in the 22 CRT devices. Mean fluoroscopy time was 10±6 min including implant of all leads, without differences between implants. Electrical parameters were highly favourable in all patients (mean threshold 0.73±0.27V and mean sensing 11±5.8 mV) without differences between the 2 sheaths. Pacing impedance was significantly lower in the Selectra 3D group. Paced QRS duration was 114±15 ms (112±14 vs 116±16 ms; P 0.180). Implant failure were 4 (2 due to severe tricuspid regurgitation and 2 to severe dilated atria).

Conclusion

LBBP is highly reliable in clinical practice. The different sheath available lead to successfully perform the implant in different cardiac anatomies. In our experience there was no differences in technical acute outcome between implant guided by C315 Medtronic sheath and Selectra3D Biotronik sheath.

P80 PROGNOSTIC IMPACT OF NEW ONSET ATRIAL FIBRILLATION AFTER SINGLE OR DOUBLE STENT LEFT MAIN BIFURCATION PCI

Objective

Incidence and prognostic value of new onset atrial fibrillation (NOAF) after single versus double stent strategy in bifurcation Left Main (LM) disease has not been yet investigated.

Methods

We retrospectively analysed the procedural and medical data of patients referred to our center for complex LM bifurcation disease, treated using Cross–over provisional stenting, T or T–and–Protrusion (TAP), Culotte, and Nano–inverted–T (NIT) techniques between January 1st, 2008 to May 1st 2018. Multivariate Cox–regression analysis was used to assess the role of different stent strategies, adjusted for confounders, on the risk of NOAF during the follow–up period.

Results

Five hundred and two patients (316 males, mean age 70.3±12.8 years, mean Syntax score 31.6±6.3) were evaluated. At a mean follow–up of 37.1±10.8 months (range 22.1–39.3 moths), Target lesion failure (TLF) rate was 10.1%. Stent thrombosis and Cardiovascular mortality were observed in 1.2% and 3.6% in of cases, respectively. NOAF occurred in 23 out of 502 patients (4.6%). Patients with NOAF resulted more frequently female, older, obese, diabetic and more frequently experienced TLF and cardiovascular death. NOAF free survival favoured single versus double stent technique and among double stent techniques NIT compared to the others. Single stent strategy had a lower risk of NOAF compared to double stent technique on multivariate analysis (HR: 1.14, 95% CI: 1.10–1.19, p < 0.001 vs HR: 1.28, 95% CI: 1.23–1.32, p < 0.0001).

Conclusions

NOAF in distal LM bifurcation disease treated with PCI had a low incidence but resulted more frequent after double than after single stenting technique and associated with worse outcomes.

3D electro-anatomical mapping to guide conduction system pacing in complex cardiac anatomies

Background

Conduction System Pacing (CSP) includes both His Bundle Pacing (HBP) and Left Bundle Branch Pacing (LBBP). It guarantees physiological cardiac activation and it is essential to avoid pacing-induced dyssynchrony. Markedly dilated atria, up-grading to CRT, and congenital cardiopathies still represent complex anatomical scenarios in which the available tools could often result inadequate and graved by suboptimal results.

Objective

To evaluate the feasibility and effectiveness of 3D electro-anatomical mapping (EAM) to guide CSP (both HBP and LBBP) in patients with characteristics that allows “a priori” classification as complex anatomical scenario with low probability of success using only fluoroscopic guidance and available tools. Left atrium area >40 cm2; post-PICM up-grading and congenital heart disease were considered signs of anatomical complexity.

Methods and results

The study includes 25 patients (19 males, mean age 76–11 years; mean baseline EF 34.2–12.6%; 17 BBB; 5 post-PICM up-grading), candidates for CSP. 16 and 9 were respectively implanted with PM and ICD (13/12 dual/three-chamber devices). CARTO system was used in 6 ptss and EnsiteTM Precision in 19. EAM involved reconstruction of the right atrium and sub-tricuspid septum with the use of a decapolar catheter. Several “tags” have been placed on the His signals, in order to reconstruct the “His Cloud” and distinguish within it the proximal, medium, and distal area (Fig. 1). The sub-tricuspid septum was always reconstructed so that intra-procedurally operator could easily move from HBP to LBBP based on electrical parameters or paced QRS morphology. The mapping catheter was removed after the mapping phase and replaced with the pacing lead. Both exposed fixed screw 3830 leads and standard stylet-driven leads were used. HBP was achieved in 10 pts and LBBP in 13 pts. Three failures were resolved by CS lead implant. The time spend for His cloud mapping was 18±7 min. The mean threshold was 1.1±0.5 V; sensing 11.6±9.3 mV and impedance 786±339 ohm. Baseline QRS 155±19 ms and paced QRS 119±7 ms. In cases of LBBP we were also able to measure on the EAM map the depth of the catheter within the septum, resulting in 11.5±3.1 mm and the distance of the initial screw site from the His of 26.5±10.3 mm.

Conclusions

The electro-anatomical mapping allows the accurate reconstruction of “His cloud” by properly distinguishing proximal, middle, distal His. The sub-tricuspid zone of the interventricular septum is also reconstructed in high definition, so that intra-procedurally it is possible to easily move from HBP to LBBP and vice-versa based on the electrical parameters and paced QRS morphology. This method appears safe and effective even in complex cardiac anatomies possibly saving time and fluoroscopy use. The tags on the His cloud and sub-tricuspid septum can satisfactorily guide lead placement with high reproducibly.

Funding Acknowledgement

Type of funding sources: None. Figure 1. 3D-EAM used to guide HBP implant

Left bundle branch pacing: 2 year single-centre experience

Background

Left Bundle Branch Pacing (LBBP) ensures a physiologic ventricular activation and shows better electrical parameters compared to His bundle pacing (HBP). A growing body of experience is encouraging a large applicability.

Objective

To analyse feasibility and technical outcomes of LBBP in the daily clinical practice.

Methods

During 2019 and 2020, 132 patients (mean age 79±10 years; 72 males) with standard indication for pacing, received the lead deeply intraseptal aiming to pace the left bundle. The indication for pacing were AV block 72 (55%) pts, SND 14 (11%), AF and slow ventricular rate 21 (16%), ablate&pace in 4 (3%); HF in 10 (7.5%), PICM 6 (4%) pts, lead revision in 5 (3.5%). 75% of pts had ischemic cardiopathy; 82% hypertension, 30% diabetes and 21% severe kidney disease. Baseline QRS was 141±38 ms and 68% of pts had bundle branch block. The basal mean EF 49±15%. 91 (69%) of the pts were in sinus rhythm at implant. Criteria for LBBP were: RBB morphology in V1 together with left ventricular activation time (LVAT)<80 ms in V6. Final lead position was always confirmed with injection of 5 ml of dye contrast in left anterior oblique view.

Results

The lead was successfully implanted in the left bundle in 129 (97,7%) patients. In the remaining 3 patients the cathode only penetrated the septum. In 90 cases LBBP was the first choice, in the remaining 42 patients LBBP was aimed after unsatisfactory HBP (His threshold>2V or paced QRS>140 ms). In 107 cases we utilized the 3830 4Fr lumenless lead; in 25 cases the stylet-driven 6 Fr leads. The LBBP lead was connected to the RV port in the 92 dual-chamber PMs; in the LV port in the 22 three-chamber devices as part of cardiac resynchronization therapy; in the only port in 18 single-chamber PM. Mean fluoroscopy time was 10±6 min including implant of all leads. Electrical parameters were highly favourable (R wave sensing 10,5±5 mV; threshold 0,9±0,2 V@0,5 ms; impedance 829±234 ohm). Paced QRS duration was 114±20 ms (P<0.005). The devices were checked 48 hours after implant and 1 month later. Thereafter were remotely monitored. At the 1-month in clinic interrogation all LB lead showed good performance and QRS morphology and duration like the post implant one (115±21 ms). Mean VP% was 81% and mean AP% 28%. VP ≥90% was detected in 42 (32%) of patients. Chronic AF (AT/AF 100%) in 24 (18%) of patients. In 3 cases the LB lead showed early dislodgement requiring lead revision (1 macroscopic dislodgement and 2 rise in threshold), all of them within 7 days after implant.

Conclusion

The new technique of pacing the left bundle of the conduction system (LBBP), is safe and feasible in the clinical practice. It is applicable in all pacing indications including heart failure and resynchronization. In our experience lead dislodgement were 2,2% (3/132, all in the first week after implant) whereas paced QRS duration was significantly shortened and ejection fraction remained normal.

Funding Acknowledgement

Type of funding sources: None.

Selectra 3D- guided conduction system pacing: single-center experience

Background

Conduction system pacing (CSP)is becoming increasingly popular thanks to the ability to both maintain physiological electrical activation in patients with narrow QRS and restore ventricular synchrony in patients with bundle branch block (BBB). The Selectra3D introducer is a new tool able to support the correct positioning and screwing of the catheter on the bundle of His (HBP) or on the left branch (LBBP). It does exist in 3 different shapes: S, M, L (Fig. 1) based on the radius of main curvature. The internal diameter of 7.3 Fr allows it to support both the 3830 lumen-less catheter historically used for CSP, as well as standard 6Fr stylet-driven leads.

Objective

To evaluate the effectiveness of the Selectra3D introducer for CSP (including both HBP and LBBP), considering the procedural success rate and the lead stability (stability of electrical parameters or need for implant revision) in the medium-term follow-up.

Methods and results

The Selectra3D introducer was used in 56 patients' candidates for CSP (mean age 80±6 years). Pacing indications included A-V block in 21 patients, AF with slow ventricular response in 9 patients; SND in 8 patients and HF and severe ventricular dysfunction in 18 patients (of which 4 were PICM). The mean baseline EF was 40±15%. A PM was implanted in 40 patients and an ICD in 16. A standard stylet-driven lead was used in 48 cases, a fixed exposed screw lead was used in 8 patients. HBP was obtained in 21 cases and LBBP in 30 cases, while in 5 cases (8.9%) neither HBP nor LBBP could be obtained. Implants were performed via a left-sided approach in 55 cases and a right-sided approach in 1 case. The baseline QRS duration was 144±38 ms and the paced QRS duration was 118±21 ms. The electrical parameters were optimal with sensing 8.7±8 mV; impedance 625±276 ohm; threshold 1±0.5 V. During follow-up, 2 lead dislodgement (3.9%) (1 HBP and 1 LBBP) were recorded, both within 7 days after implantation. All the others showed stability of the electrical parameters at a mean follow-up of 8.4±4.2 months.

Conclusions

The new Selectra3D introducer supports effectively and safely the lead implant on conduction system catheters (HBP and LBBP), allowing the implant of both exposed fixed screw leads and standard stylet-driven leads, leading to procedural success>90%. The electrical parameters were optimal at implantation and remained stable during follow-up.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Reduction in QRS area correlates with hemodynamic response during CRT-device implantation

Funding Acknowledgements

Type of funding sources: None.

Background Previous studies have shown that reduction in QRS area after cardiac resynchronization therapy (CRT) is associated with improved long-term clinical outcome.

Purpose To investigate whether reduction in QRS area is associated with hemodynamic improvement and whether QRS area reduction could be used for CRT optimization, with respect to LV lead position and device programming in individual patients.

Methods A total of 78 patients with indication for CRT were prospectively included in 4 hospitals. QRS area was calculated from vectorcardiograms that were synthesized from 12-lead ECG’s. Acute hemodynamic response was assessed invasively as the maximum rate of percentual left ventricular (LV) pressure (%LVdP/dtmax) rise.  QRS area reduction was studied in relation to LV-lead position (n = 26), proximal versus distal LV lead position (n = 27), and VV-delay (n = 25).

Results Combining all measurements in all patients showed a significant correlation between QRS area reduction and %LVdP/dTmax increase (R = 0.49, P < 0.0001).  Also, when one fixed routine implantation setting was used for each patient (lateral lead position, distal, AV-delay 120-150ms, VV-delay 0ms) this correlation was present (R = 0.45, p < 0.0001, figure panel A). In 21 patients in which at least 3 lead positions were available there was also a significant correlation between QRS area reduction and %LVdP/dtmax increase (average R = 0.69, p < 0.0001, panel B). For VV-delay, 25 other patients as well showed a significant correlation (average R = 0.53, p < 0.0001).

Conclusion Within patients, QRS area reduction is associated with %LVdP/dtmax increase with various LV lead positions and VV-intervals. Therefore, QRS area, which is an easily obtainable and objective parameter, might be a promising tool for optimization of LV lead position and device programming in CRT. Abstract Figure.

Electrograms guided his bundle pacing implant: moving from radiology to electrical signals

Background

The standard technique to His Bundle Pacing (HBP) based on a fluoroscopic approach might be challenging and fluoro consuming. The electrical signals could lead to a precise and rapid lead implant, thus reducing the fluoroscopy time (FT) and X-ray dose.

Objective

To evaluate the feasibility, efficacy and safety of the electrogram-guided technique to obtain His Bundle pacing (HBP) with minimal or no fluoroscopy use.

Methods

Between October and December 2018, 41 consecutive patients with indication for pacing underwent HBP with the electrogram-guided approach.

Results

Successful HBP was obtained in 39/41 (95%) pts, which is the study population (mean age 78±10 years). S-HBP and NS-HBP were achieved in 23 (59%) and 16 (41%) pts, respectively. Final HBP lead position was achieved in 31/39 (79.4%) pts with zero fluoroscopy, only guided by the electrical signals. In the remaining 8 pts a minimal dose of fluoro (mean 8 sec) has been required to locate the His. Fluoroscopy has been routinely used to remove the sheath and to ensure the slack. The atrial lead has been implanted in a standard fashion. No difference was observed in the FT for HBP lead placement in patients with S-HBP and NS-HBP (mean 8.1±25 sec vs 7.5±20 sec, p=0.8; median value 0 sec vs 0 sec). Moreover, no significant differences were observed in the FT needed for the entire procedure, total Dose Area Product (DAP) and total procedural time among both S-HBP and NS-HBP. The His lead dislodgement occurred in 1 (2.6%) patient one day after the procedure.

Conclusion

HBP could be performed safely and efficiently using the electrograms, with minimal or no fluoroscopy. Fluoroscopy was required during sheath removal and atrial lead placement.

Funding Acknowledgement

Type of funding source: None

The challenge of education in conduction system pacing: results from single or dual operators

Background

The his bundle pacing (HBP) and Left bundle branch pacing (LBBp) techniques are quickly increasing in the cardiovascular interest being the most physiological mode of pacing. Education in these new conduction system pacing (CSP) is mandatory in the modern EP programs. Achieving acceptable implant success rate, together with electrical parameters adequacy is required.

Objective

The aim of the study was to compare clinical and technical outcomes in 2 groups of patients, those implanted by a single operator with large expertise in CSP and those implanted by two operators (one of them during his learning curve).

Methods

Data from 255 consecutive patients (mean age 78±9 years; 186 males) who underwent successful HBP or LBBp implants were collected and analyzed. The operators were classified as expert after performing more than 50 procedures. Baseline caracteristics were not significantly different between the two groups.

Results

After a mean follow-up of 20±10months, we found that there were no differences between patients implanted by 1 single expert operator and 2 operators (1 beginner during his learning cirve supervised by 1 expert operator) in terms of clinical end point (composite of death or heart failure hospitalizations) and technical end point (need for surgical revision of the implant for reason other than battery replacement). Fluoroscopy time (16±17 min vs 9.8±11 min; p 0.004) and procedural time (113±48 min vs 16±17 min; p 0.003) were significantly prolonged when the implant was performed by 2 operators.

Conclusions

Skill acquisition in physiological pacing (both HBP and LBBp) is a nowadays process which cannot put patient's safety at risk. Our experience shows that clinical and technical outcomes were equivalent when the implant was performed by an expert operator or a beginner operator supervised by 1 expert operator. Fluoroscopy time and duration of the procedure were significantly prolonged by the presence of a trainees.

Kaplan Meyer curves

Funding Acknowledgement

Type of funding source: None

The back-up lead in his bundle pacing: evolution over the years

Background

His bundle pacing (HBP) can be affected by high thresholds and low sensing. Thus, in selected patients including a back-up lead is advisable.

Objective

Single-centre retrospective analysis of a large HBP experience, focusing on the back-up lead utilization over the years.

Methods

677 pts (76±8 years; 433 males) were implanted with HBP from 2004 to 2019 July. The pts received S-HBP (67%) or NS-HBP by the 3830 lead. The pacing indications were AV block 54%, sinus node disease 17%, slow atrial fibrillation 23%, heart failure 6%. Ischemic cardiopathy was found in 26%; hypertension in 83%, diabetes in28% pts. Baseline QRS duration was 123±32 ms and EF 56±12%.

Results

266 (39%) pts received the back-up lead. In sinus rhythm we implanted 3-chamber PM (His lead:LV port; VV delay 80 ms: His pulses and apical pacing during the refractory period). 30 pts (11%) received a particular type of 3-chamber PM which provides back-up pacing only if His capture fails, thus saving energy. In atrial fibrillation 2-chamber PM was implanted (His lead: atrial port, DVI). We recorded a significant decrease of back-up lead use over the years, strictly related to operators/centre experience (>70% during the first years, nearly 10% during the last year). The C315 fixed curve sheath, strongly contributed to the rapid reduction of back-up lead use thanks to better lead fixation and stability.

Conclusion

The back-up lead utilization is progressively decreasing. It is strictly related to the operator/centre experience. The presence of the back-up lead could strengthen the Hisian pacing reliability, potentially impacting pacing indication even in advanced conduction disturbances and saving device longevity.

Funding Acknowledgement

Type of funding source: None

Wastewater disinfection: long-term laboratory and full-scale studies on performic acid in comparison with peracetic acid and chlorine

Chemical disinfection of municipal wastewater to preserve the microbiological quality of discharges has traditionally relied on chlorine, and more recently on peracetic acid (PAA). A more recent option is performic acid (PFA). This work uses laboratory and full-scale studies over a span of 15 years and five wastewater treatment plants (WWTPs) in Italy, to compare the efficacy of these three disinfectants and identify the differences among peracids in a context where both can be an alternative to chlorine. The investigations focused on treatment effectiveness and bacterial inactivation kinetics using E. coli and the more resistant enterococci, as well as on PFA and PAA decomposition as the residuals may affect the downstream microenvironment. Furthermore, the potential for the two peracids to oxidize organic substances and create troublesome byproducts was also studied. Chlorine, applied as hypochlorite ("HYP") and here essentially functioning as chloramines, was used as a baseline comparison for the two peracids. Appropriate statistical tests were applied to the data from different WWTPs to account for potential interferences and compounding effects of the different matrices. Average doses of 0.8, 2.9 and 1.4 mg/L and contact times of 18, 21 and 31 min, respectively for PFA, chlorine and PAA guaranteed with a high level of assurance the 5000 CFU/100 mL E. coli limit; the order of effectiveness was PFA > HYP > PAA, refined as PFA > HYP ≈ PAA against E. coli and PFA ≈ HYP > PAA with enterococci. Similar bacterial reductions for the peracids were found at higher disinfectant doses used for the kinetic tests. PFA decayed more quickly than PAA. The first-order decay constants were 0.031 and 0.007 min^-1, respectively, suggesting that disinfection residuals when PFA is used may be less of a concern than with PAA. This faster decomposition did not affect the PFA oxidation power on estrone, which was as weak as that of PAA.

Uptake and translocation of perfluoroalkyl acids (PFAAs) in hydroponically grown red chicory (Cichorium intybus L.): Growth and developmental toxicity, comparison with growth in soil and bioavailability implications

Short-chain perfluoroalkyl acids (PFAAs) have shown a high potential for plant (crop) uptake, making them possibly significant contributors to the total dietary exposure to PFAAs. The plant uptake of PFAAs is a complex process that needs better characterization, as it does not only depend on perfluoroalkyl chain length, but also on their polar terminal group, on the plant species and the exposure media. Here, a plant uptake study with nine perfluoroalkyl acids (PFAAs) was carried out under the hydroponic (soilless) exposure conditions. Red chicory was grown in a nutrient solution, spiked with PFAAs mixture at three different concentrations (i.e. 62.5, 125 and 250 μg/L), in order to extend the range of levels tested and reported in the literature so far. Bioaccumulation metrics and transpiration stream concentration factors (TSCFs) were employed for the plant uptake characterization and consequent comparison with the results of soil uptake experiment we previously performed with the same crop. The results showed that calculated root concentration factors (RCFs) increase with PFAA chain length, while the opposite chain length dependence was present for shoots. Plants from two treatments with the highest PFAAs concentrations manifested physiological changes (discoloration, inhibited roots and leaves growth), despite of the used exposure concentrations being much lower than previously published phytotoxicity thresholds. A comparison among RCFs and TSCFs derived from hydroponic and from the soil experiment has emphasized their different magnitudes and PFAAs chain length dependence patterns. They could not be ascribed only to soil sorption as a process decreasing PFAAs bioavailability for plants, but also to developmental differences between the root systems formed in soil and in nutrient solution and to the potential competitive PFAAs sorption to roots in hydroponics. The interchangeable use of bioaccumulation and translocation parameters derived in hydroponic and soil systems would lead to erroneous conclusions and plant uptake predictions.

P544Evaluation of three-dimensional trajectory of pacing cathode pole in coronary sinus to predict long-term response to cardiac resynchronization therapy

Background

An automated method for 3D reconstruction of coronary sinus (CS) lead’s pacing cathode trajectory (3DTJ) was proposed  to acutely predict long term left ventricular (LV) mechanic response to  cardiac resynchronization therapy (CRT). Preliminary data showed that 3DTJ at biventricular pacing (BIV) start changed  in CRT responders (R) to be,  becoming less eccentric and more multi-directional, as described by the ratio between its two major axes (S1/S2).

Purpose

The TRAJECTORIES study (Trajectory Changes Of Coronary Sinus Lead Tip And Cardiac Resynchronization Therapy Outcome, NCT02340546) is an observational study by seven Italian centers about  the prediction of CRT-induced LV reverse remodeling by means of the acute 3DTJ changes at CRT implant.

Methods

In CRT implants with standard indications, stable CHF and regular ventricular rhythm,  a fluoroscopic sequence in two standard X-rays views of a few seconds was acquired immediately before (T-1) and after the start of BIV (T0). 3DTJ  of CS lead cathode pole throughout the cardiac cycle at T-1 and T0 were reconstructed and analyzed. Changes of the ratio between its two major axes (S1/S2) between T-1 and T0 (ΔS1/S2), were compared with the volumetric response at six-month f.u: the percent negative variation of S1/S2 (ΔS1/S2 < 0), marking a more multi-directional shape of 3DTJ, was assumed to predict the response to CRT. Volumetric response was adjudicated by a core-lab using a cut-off reduction ≥ 15% in echocardiographic LV end-systolic volume at f.u.. 

Results

  Out of 119 patients enrolled in 42 months, 74 pts ended f.u. (55 m; age 69 ± 10) and 30 dropped–out. Patients baseline features were: ischemic heart disease (IHD) 34 /74 pts; sinus rhythm 64/74 pts; upgrade from PM/ICD 13/74 pts; QRS morphology with LBBB 57/74, intraventricular aspecific delay 6 and  RV pace 11 pts;  LV ejection fraction (EF) 30 ± 9%; QRS duration 162 ± 25 ms. At f.u., volumetric R were 45/74 (60%). Concordance between ΔS1/S2 (as either ΔS1/S2 < 0 or ΔS1/S2 > 0) and volumetric response was 77% overall (57/74), 82% in R (37/45), 69% in non-R (20/29). Non-concordant patients were mostly non-R: 52% vs  35% of non-R in concordant group, but no other differences were found. The proposed 3DTJ metric showed sensitivity = 72%, specificity =80%;  positive predictive value = 69%, negative predictive value = 82%.

Conclusions

Metrics of 3DTJ can be useful to acutely predict CS pacing site-specific response to CRT in long-term, above all in R. 3DTJ assessment might highlight aspects of  CRT effects  on LV mechanics.

841Multi-center clinical experience with the usage of implantable pulse generators for permanent his bundle pacing

Funding Acknowledgements

Abbott

Introduction

His Bundle pacing (HBP) offers a more physiologic pacing approach to maintain electrical synchrony. Permanent HBP has emerged as a feasible and safe alternative to traditional pacemaker therapy and cardiac resynchronization therapy (CRT) with clinical and electrophysiological advantages. However, traditional implantable pulse generators (IPGs) have been used for HBP without supporting algorithms developed for HBP.

Objective

To assess a multi-center clinical experience with the usage of IPGs for permanent HBP and to identify the needs for HBP specific device algorithms.

Methods

Patients from 6 centers worldwide with a permanent HBP lead and an existing Abbott pacemaker, defibrillator, or CRT device were enrolled in this study. Device data and 12-lead surface ECG were collected simultaneously during device interrogation at a follow-up visit. HBP capture types at different pacing amplitudes were adjudicated using 12-lead ECG. Bundle branch block (BBB) correction by HBP was defined as QRS duration ≤130 ms or narrowing by >20%. Amplitudes of atrial and ventricular components on the HBP lead from both unipolar and bipolar sensing configurations were measured. Amplitudes of atrial component ≥ 0.5 mV on HB sensing EGMs were measured and considered as having risk of atrial oversensing.

Results

A total of 133 patients (75 ± 10 yrs, 92 male) were enrolled and completed study data collection post implant (median: 48, range: 0-3110 days). Patient characteristics, IPG type, and HBP lead connections were shown in the table. Dual-chamber pacemaker with HBP lead connected to V port was the most popular (65%) configuration. In non-BBB patients, pacing thresholds for selective HB (n = 44), non-selective HB (n = 54), and myocardial capture (n = 21) were 1.5 ± 1.2, 2.9 ± 2.0, 1.4 ± 1.5 V, respectively, at pulse width of 0.8 ± 0.4 ms. In BBB patients, LBBB and RBBB were corrected in 10/23 (43%) and 12/27 (44%) patients with pacing thresholds of 3.5 ± 2.4 and 2.1 ± 2.0 V, respectively, at pulse width of 0.8 ± 0.3 ms. AutoCapture™ algorithm was tested in 63 patients and recommended to be OFF in 28 (44%) patients. EGMs during intrinsic AV conduction were collected in 86 patients. A risk of atrial oversensing was identified in 24 (28%) and 27 (31%) patients during bipolar and unipolar sensing, respectively, and in 17 (20%) patients during both configurations. The average amplitude of the atrial and ventricular components on the HB lead EGM were 2.1 ± 2 and 6.0 ± 5.8 mV during bipolar sensing and 1.3 ± 1.2 and 6.3 ± 6.5 mV during unipolar sensing, respectively. Five (6%) patients had A/V amplitude ratios higher than 1.

Conclusions

Currently, various device configurations are used to overcome the fact that IPGs are not designed for HBP. Additionally, HBP presents unique challenges to ensure appropriate capture and sensing beyond traditional RV pacing. HBP specific device algorithms are needed to ensure correct IPG usage and facilitate device programming.

Abstract Figure.

Uptake and translocation of perfluoroalkyl acids (PFAA) in red chicory (Cichorium intybus L.) under various treatments with pre-contaminated soil and irrigation water

Perfluoroalkyl acids (PFAAs), particularly short-chained ones, have high potential for crop uptake, posing a threat to human health in contaminated areas. There is a scarcity of studies using contaminated water as the medium for PFAAs delivery to crops, and a lack of data on the partitioning of PFAA mixtures in growing media. In this context, a controlled experimental study was carried out in a greenhouse to investigate the uptake of a PFAA mixture into red chicory, a typical crop from a major PFAA contamination hot-spot in northern Italy, under treatments with environmentally relevant concentrations in spiked irrigation water and soil, separately and simultaneously. To our knowledge, this is the first study involving multiple exposure media and laboratory adsorption/desorption batch tests as a way of assessing the decrease in the bioavailability of PFAAs from soil. Exposure concentrations for each of the 9 utilized PFAAs were 0, 1, 10 and 80 µg/L in irrigation water and 0, 100 and 200 ng/gdw in soil, combined into 12 treatments. The highest bioaccumulation was measured for PFBA in roots (maximum of 43 µg/gdw), followed by leaves and heads of the chicory plants in all treatments, with the concentrations exponentially decreasing with an increasing PFAA chain length in all plant compartments. The use of irrigation water as the delivery medium increased the transport of PFAAs to the aerial chicory parts, long-chain substances in particular. Additionally, the distribution of PFAAs in the soil was assessed by depth and compared with laboratory measured soil-water equilibrium partition coefficients, revealing only partial dependency of PFAAs bioavailability on the adsorption in soil.

Immunoaffinity Column Cleanup with Liquid Chromatography for Determination of Aflatoxin B1 in Corn Samples: Interlaboratory Study

An interlaboratory study was conducted to evaluate the effectiveness of an immunoaffinity column cleanup liquid chromatography (LC) method for the determination of aflatoxin B1 levels in corn samples, enforced by European Union legislation. A test portion was extracted with methanolwater (80 + 20); the extract was filtered, diluted with phosphate-buffered saline solution, filtered on a microfiber glass filter, and applied to an immunoaffinity column. The column was washed with deionized water to remove interfering compounds, and the purified aflatoxin B1 was eluted with methanol. Aflatoxin B1 was separated and determined by reversed-phase LC with fluorescence detection after either pre- or postcolumn derivatization. Precolumn derivatization was achieved by generating the trifluoroacetic acid derivative, used by 8 laboratories. The postcolumn derivatization was achieved either with pyridinium hydrobromide perbromide, used by 16 laboratories, or with an electrochemical cell by the addition of bromide to the mobile phase, used by 5 laboratories. The derivatization techniques used were not significantly different when compared by the Student's t-test; the method was statistically evaluated for all the laboratories. Five corn sample materials, both spiked and naturally contaminated, were sent to 29 laboratories (22 Italian and 7 European). Test portions were spiked with aflatoxin B1 at levels of 2.00 and 5.00 ng/g. The mean values for recovery were 82% for the low level and 84% for the high contamination level. Based on results for spiked samples (blind pairs at 2 levels) as well as naturally contaminated samples (blind pairs at 3 levels), the values for relative standard deviation for repeatability (RSDr) ranged from 9.9 to 28.7%. The values for relative standard deviation for reproducibility (RSDR) ranged from 18.6 to 36.8%. The method demonstrated acceptable within- and between-laboratory precision for this matrix, as evidenced by the HorRat values.

P6547The energy cost of His bundle pacing can be curtailed

Introduction

His bundle pacing (HBP) allows physiological ventricular activation and prevents the electrical and mechanical desynchronization generally induced by myocardial stimulation, which can increase the risk of atrial fibrillation and heart failure. On the other hand, reliable HBP capture often requires higher energy than conventional myocardial pacing. This reduces the expected life of the stimulator and might limit the diffusion of HBP in the clinical practice.

Purpose

Decreasing HBP current drain by careful management of stimulation safety margin and pulse duration.

Methods

In 28 patients undergoing DDD pacing with HBP, a third lead was implanted in RV apex to provide back-up pacing on demand. HBP and apical leads were connected, respectively, to the V1 and V2 channels of a 3-chamber stimulator. When HBP was effective, apical sensing occurred within the VV delay and prevented V2 stimulation. In contrast, in case of HBP failure, V2 sensing was missing and apical back-up pacing was promptly delivered at the end of the VV delay. The availability of a back-up pulse on demand allowed reducing the HBP safety margin with no risk. Furthermore, the individual HBP strength-duration curve was derived in the aim of optimizing the Hisian pulse parameters, which are the major determinants of the device current drain.

Results

Correct back-up inhibition by successful HBP and stimulation in the event of capture loss was achieved in all the patients. The latency from Hisian pacing to apical sensing averaged 96±14 ms. According to the pacemaker counters, no back-up pulse was delivered in daily life in 59% of patients. In the remaining, the prevalence of back-up stimulation never exceeded 15% of paced ventricular cycles. The high HBP threshold was essentially due to an increased rheobase (1.2±0.6 V), while the chronaxie ranged from 0.30 to 0.53 ms in 71% of patients (median 0.44 ms), exceeding 0.6 ms only in 29% of the cases. An average current saving of 5.4±3.0 μA was obtained at the expense of a mild reduction in HBP safety margin (from 1.6±0.2 to 1.4±0.1 times).

HBP and apical back-up

Conclusions

Back-up stimulation on demand is a reliable option to decrease HBP current drain and prolong the stimulator service life with full safety. In most of the cases, significant saving can be achieved by pulse shortening, as the chronaxie time is in the same range as with myocardial stimulation and longer pulses are not required. A pulse duration exceeding 0.6 ms is indicated in less than 1/3 of the implants.

P5238Rate, cause and costs of Heart Failure hospitalizations following ICD/CRT-D replacement: preliminary data from an Italian multicenter registry

Background

Heart failure hospitalizations (HFHs) likely represent the main health care expenditure also in implantable cardiac defibrillators (ICDs) and cardiac resynchronization therapy defibrillators (CRT-D) recipients yet the event rate of HFH and the associated costs after device replacement or upgrade are unknown.

Purpose

To report HFH rates and associated costs within 12 months following ICD/CRT-D device replacement or upgrade procedure from ICD to CRT-D.

Methods

The DEtect long-term COmplications after icD rEplacement (DECODE) was a prospective, single-arm, multicenter cohort study exploring complications in ICD/CRT-D recipients undergoing device replacement or upgrade from ICD to CRT-D. All clinical and survival data of these patients at 12-month follow-up were prospectively analyzed. For each adjudicated HFH, the admission and discharge date were recorded, and ICD-9-CM diagnoses and procedure codes were obtained. The estimated reimbursement for each hospitalization was calculated according to the 2012 Italian national reimbursement rates.

Results

Between 2013 and 2015, 983 patients (mean age = 71 years, mean LVEF = 35%, NYHA class I/II = 75.6%) were enrolled: 900 (91.6%) patients underwent device replacement (446 ICD/454 CRT-D) and 83 (8.4%) upgrade from ICD to CRT-D. After 12 months, 66 (6.7%) patients died, 40 (60.6%) for cardiovascular reasons. Fifty-five (5.6%) patients experienced at least 1 HFH. Overall, 91 HFH (9.6% event rate 95% CI, 7.7–11.7) occurred. Among the variables tested at univariate analysis, only LVEF ≤35%, AF history and renal disease were confirmed as HFH predictors at multivariate analysis. HFH rate was significantly higher following upgrade procedures and occurrence of HFH was associated with an eleven-fold increased mortality risk (95% CI: 5.9 to 20.5; p<0.0001). The cumulative cost associated with HFHs incurred over the 12 months follow-up was 515305 €. The mean cost per HFH was 5662±9497 € [ranging from 3144 € to 64479 €] while the mean cost per patient with events was 9369±12687 €.

Conclusion

Underlying cardiac disease and renal failure are the main drivers of HFH and mortality, and of higher healthcare expenditures in ICD/CRT-D recipients following device replacement or upgrade. Accurate clinical assessment is needed to support the decision-maker at the time of ICD replacement to take an appropriate clinical and economic sustainable decision.

Acknowledgement/Funding

None

P2871Attenuated clinical benefit after ICD replacement over long term follow-up in a contemporary large world population: insight to the DECODE registry

Background

Cardiac Implantable Electronic Device (CIED) surgery is threatened by serious complications both during the procedure and during follow-up. The factors associated to attenuated clinical benefit over long term follow-up are poorly understood.

Purpose

To evaluate type and extent of Adverse Events (AEs) and potential predictors of major AEs over 12 months after ICD/CRT-D replacement/upgrade in a contemporary Italian population.

Methods

Detect long-term complications after ICD replacement (DECODE) was a prospective, single-arm, multicenter cohort study aimed at estimating medium- to long-term complications in a large population of patients (pts) who underwent ICD/CRT-D replacement/upgrade from 2013 to 2015. The endpoint for this analysis is death from any cause, procedure-related infection, and surgical actions/hospitalizations necessary to treat the AEs.

Results

We included 983 consecutive pts (median age 71 years, 76% male, 55% ischemic, 47% CRT-D). During a mean follow-up duration of 353±49 days, 7% of the pts died. A total of 104 AEs occurred in 70 (7.1%) pts. 43 (4.4%) pts needed at least one surgical action to treat the AEs. A total of 23 (2.3%) pts had infective AEs (CIED related in 12 pts, due to other causes in 11). Mortality was unrelated to the occurrence of overall AEs, or of CIED-related AEs, or of surgical actions/hospitalizations needed to correct AEs. The endpoint was reached by 109 (11%) pts over 12-month follow-up (97 pts had a single event, and 12 pts had two events). The median time to the endpoint was 137 [50 - 254] days. On multivariate Cox regression analysis adjusted for baseline confounders, ischemic cardiomyopathy (HR = 1.86, 95% CI: 1.18 to 2.91; p=0.0076), hospitalization prior to the procedure (2.34, 1.35 to 4.05; 0.0025) and anticoagulation (1.91, 1.25 to 2.92; 0.0032) were associated with the endpoint during follow-up.

Conclusion

Evaluation of the patient's profile may assist in predicting vulnerability and should prompt reconsideration of the procedure by deferring at a more stable clinical status, and carefully individualized in the setting of upgrades and anticoagulation management

Acknowledgement/Funding

None

Trace elements: critical insights from 15 years of monitoring in the Venice Lagoon catchment basin (Italy)

The study focused on selected trace elements (As, Cd, Cr, Hg, Ni, Pb) monitored in surface waters of the Venice Lagoon catchment basin (North East Italy) over the period 2000-2015. The monitoring was undertaken to verify the achievement of the quality objectives set by the European and national legislations. The available results have been analyzed to evaluate the chemical status of water bodies. The limit of quantification (LOQ) of the applied analytic techniques appears critical for the adequate water monitoring; for some parameters, the percentage of not visible values due to non-satisfactory LOQ was higher in the beginning of the period; the subsequent improvement of LOQ allowed assessing the respect of environmental quality standards (EQSs). The study analyzes time trends in single stations and the differences between detected concentrations in the considered stations. Moreover, maximum concentrations and water flows have been considered to understand the potential correlation. Cumulated frequency curves for the most critical parameters have been built to identify situation of potential overtaking of the EQSs in force. The most polluted sampling stations of the drainage basin for the six trace elements were found in Cuori and Fiumazzo rivers. Although LOQs changed over time, the recorded trends show a quality improvement and a good compliance with respect to EQSs set by European legislation, while considering EQSs set by local special legislation, the objectives are not yet satisfied. Arsenic is ubiquitous; thus, it can be supposed to be originated as a background environmental concentration, while nickel appears of industrial origin according to its point and local presence.