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.

Impact of ABC pathway adherence in high-risk patients with atrial fibrillation: an analysis from the ESC-EHRA EORP-AF long-term general registry

Background

The impact of Atrial Fibrillation Better Care (ABC) pathway adherence among high-risk subgroups of patients with atrial fibrillation (AF), ie. those with chronic kidney disease (CKD), advanced age and/or prior thromboembolism remains unknown. We evaluated the impact of ABC pathway adherence on clinical outcomes in these high-risk AF patients.

Methods

The EORP-AF General Long-Term Registry is a prospective, observational registry from 250 centres across 27 European countries. High-risk patients were defined as those with either CKD (eGFR <60 mL/min/1.73 m2), older age (≥75 years) and/or prior thromboembolism. The primary outcome was a composite event of all-cause death, any thromboembolism and acute coronary syndrome, evaluated according to ABC pathway adherence.

Results

A total of 6646 patients with AF were included (median age was 70 [IQR 61–77] years; 40.2% females). There were 3304 (54.2%) `high risk' patients with either CKD (n=1750), older age (n=2236) or prior thromboembolism (n=728). Among these there were 924 (28.0%) managed as adherent to ABC.

At 2-year follow-up, a total of 966 (14.5%) patients reported the primary outcome. The incidence of the primary outcome was significantly lower in high-risk patients managed as adherent to ABC pathway (IRR 0.53 [95% CI, 0.43–0.64]). Consistent results were obtained in the individual subgroups [Table]. Using multivariable Cox proportional hazards analysis, ABC adherence in the high-risk cohort was independently associated with a lower risk of primary outcome (aHR 0.64 [95% CI, 0.51–0.80]), as well as in the CKD (aHR 0.51 [95% CI, 0.37–0.70]) and elderly subgroups (aHR 0.69 [95% CI, 0.53–0.90]). Overall, there was greater reduction in the risk of primary outcome as more ABC criteria were fulfilled, both in the overall high-risk patients, as well as in the individual subgroups [Figure].

Conclusion

In a large, contemporary European AF cohort there was a significant proportion of high-risk patients. Among these, a low prevalence of integrated care, as assessed by adherence to ABC pathway, was found. Nonetheless, a clinical management adherent to the ABC pathway was associated with a significant reduction in the risk of adverse outcomes, the benefits of which were more significant with increasing number of ABC criteria adherent.

Funding Acknowledgement

Type of funding sources: None.

Anaemia and adverse outcomes in European patients with atrial fibrillation: a report from the ESC-EHRA EORP atrial fibrillation general long-term registry

Background

Anaemia is an independent predictor of atrial fibrillation (AF) and a common comorbidity. Real world data on the impact of anaemia on clinical outcomes, and on the benefits and risks of oral anticoagulation (OAC) are limited.

Purpose

To investigate the association of different degrees of anaemia with adverse outcomes in a cohort of European patients with AF.

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry with baseline hemoglobin (Hb) values. Patients were stratified according to World Health Organization (WHO) definition of anaemia: (i) No anaemia (Hb≥12.0g/dl for women and Hb≥13.0g/dl for men), Mild anaemia (Hb 11.0–11.9g/dl for women and Hb 11.0–12.9g/dl for men), and moderate-severe anaemia (Hb ≤10.9 g/dl for both sexes). Primary outcomes were all-cause death, major adverse cardiac events (MACE, as the composite of any thromboembolism (TE)/acute coronary syndrome/cardiovascular death) and major bleeding.

Results

From the original 11,096 AF patients enrolled in the Registry, 7767 (69.9%) were included in the present analysis (median age 70 years, interquartile range [IQR] 62–77, males 58.3%, CHA2DS2VASc score median 3 [2–4], HAS-BLED median 2 [1–2]). A total of 5973 (76.9%) patients did not have anaemia, 1156 (14.9%) had mild anaemia, and 638 (8.2%) had moderate/severe anaemia. Patients with anaemia were more likely to have more comorbidities, frailty, permanent AF and polypharmacy (≥5 drugs). Overall, 318 (18.4%) patients with anaemia and an indication for anticoagulation [i.e. CHA2DS2-VASc≥1 (males), or ≥2 (females)] did not receive any OAC. After a median (IQR) follow-up of 730 (692–749) days, all-cause death was 10.5% and there were 841 (11.6%) MACE and 186 (2.5%) major bleeds. Kaplan–Meier analysis showed a higher cumulative risk for patients with moderate-severe anaemia for all the outcomes considered (Figure) (Log Rank tests, all p<0.001). Adjusted Cox regression analyses revealed that patients with mild and moderate-severe anaemia had a higher risk for all-cause death (adjusted hazard ratio [aHR] 2.02, 95% confidence interval [CI] 1.71–2.40 and aHR 2.39, 95% CI 1.97–2.91, respectively), MACE (aHR 1.44, 95% CI 1.17–1.76 and aHR 1.64, 95% CI 1.30–2.07 respectively), and major bleeding (aHR 1.52, 05% CI 1.02–2.25 and aHR 3.73, 95% CI 2.59–5.37, respectively). Among patients with moderate-severe anaemia, use of OAC was associated with lower risk of all-cause mortality (HR 0.64, 95% CI 0.46–0.89) and MACE (HR 0.55, 95% CI 0.36–0.84), without a significant increased risk of major bleeding (HR 0.81, 95% CI 0.43–1.52).

Conclusions

In a large contemporary cohort of European AF patients, almost 25% have concomitant anaemia which is associated with an increased risk for all-cause mortality, MACE and major bleeding. Use of OAC was associated with a lower risk of all-cause mortality in patients with moderate-severe anaemia, without significant increased risk of major bleeding.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Since the start of EORP, the following companies have supported the programme: Abbott Vascular Int. (2011–2021), Amgen Cardiovascular (2009–2018), AstraZeneca (2014–2021), Bayer (2009–2018), Boehringer Ingelheim (2009–2019), Boston Scientific (2009–2012), The Bristol Myers Squibb and Pfizer Alliance (2011–2016), The Alliance Daiichi Sankyo Europe GmbH and Eli Lilly and Company (2011–2017), Edwards (2016–2019), Gedeon Richter Plc. (2014–2017), Menarini Int. Op. (2009–2012), MSD-Merck & Co. (2011–2014), Novartis Pharma AG (2014–2020), ResMed (2014–2016), Sanofi (2009–2011), SERVIER (2010–2021), and Vifor (2019–2022)

ABC adherence and impact of optimal medical therapy in heart failure patients with atrial fibrillation

Background

Heart failure (HF) has close association with atrial fibrillation (AF). The ESC guideline recommended Atrial fibrillation Better care (ABC) pathway aims to reduce major cardiovascular adverse outcomes with an integrated care approach. Optimal medical treatment (OMT) represents the cornerstone in HF management.

Purpose

To investigate the variables affecting OMT treatment and its impact, in conjunction with ABC pathway adherence (vs non-adherence, ie.no ABC), in a large contemporary cohort of European AF patients with HF enrolled in the ESC-EHRA EORP-AF General Long-Term Registry.

Methods

OMT was defined as treatment with Angiotensin-converting-enzyme inhibitors (ACE-i)/ Angiotensin receptor blockers (ARBs) with Beta-Blockers and/or Mineralocorticoid receptor antagonists (MRAs), and compared to non-OMT adherence (“no OMT”). A logistic regression analysis explored factors associated with OMT adherence. We identified three patient groups: (i) HF with no OMT/no ABC; (ii) HF with OMT/no ABC; (iii) HF with OMT/ABC. Primary outcome was a composite outcome of all-cause death and major adverse cardiac events (MACE).

Results

Among the original 11096 patients enrolled, 9857 (88.8%) were included in this analysis. Among these, 3819 (38.7%) had HF. Compared to non HF patients, those with HF were older, more likely female, had more comorbidities and higher thromboembolic risk. OMT prevalence was 2228/3819 (58.3%), while ABC adherence was 23.3%.

On logistic multivariable regression, increasing age, higher BMI and higher frailty index were associated with OMT adherence, while male sex, anemia, renal disease and EHRA II–IV were inversely associated with OMT adherence. According to three HF groups, the rates of composite outcome progressively decreased (HF with no OMT/no ABC 26.4%; HF with OMT/no ABC 24%, HF with OMT/ABC 19%; p<0.001). Kaplan Meier curve showed progressively lower cumulative risk for the composite outcome across the three groups with the lowest risk among HF patients with OMT/ABC (Log-rank: p=0.002) [Figure 1]. Adjusted Cox regression analysis showed that when compared to HF with no OMT/no ABC group, there was a progressively lower risk with OMT and/or ABC adherence (HF with OMT/no ABC: HR 0.81 [95% CI, 0.64–1.02]; HF with OMT/ABC: HR 0.68 [95% CI, 0.5–0.92]).

Conclusions

After two years of follow-up, in a large contemporary cohort of European AF patients with HF, OMT adherence was suboptimal, being influenced by several clinical factors, determining a low adherence to the ABC pathway. OMT alone showed a non-significant reduction in composite outcome events. Conversely HF patients managed with OMT in the context of ABC pathway adherence showed the best reduction in risk of adverse outcomes.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Since the start of EORP, the following companies have supported the programme: Abbott Vascular Int. (2011–2021), Amgen Cardiovascular (2009–2018), AstraZeneca (2014–2021), Bayer (2009–2018), Boehringer Ingelheim (2009–2019), Boston Scientific (2009–2012), The Bristol Myers Squibb and Pfizer Alliance (2011–2016), The Alliance Daiichi Sankyo Europe GmbH and Eli Lilly and Company (2011–2017), Edwards (2016–2019), Gedeon Richter Plc. (2014–2017), Menarini Int. Op. (2009–2012), MSD-Merck & Co. (2011–2014), Novartis Pharma AG (2014–2020), ResMed (2014–2016), Sanofi (2009–2011), SERVIER (2010–2021), and Vifor (2019–2022). - I agree that this information can be anonymised and then used for statistical purposes only

Features of clinical complexity in european patients with atrial fibrillation: a report from the ESC-EHRA EORP atrial fibrillation general long-term registry

Introduction

There is increasing concern regarding the burden of clinical complexity, beyond thromboembolic risk, in patients with atrial fibrillation (AF). Also, clinical complexity is heterogenous and entails differential impact on the patients' clinical course.

Purpose

To explore different complexity features in AF patients in determining differences in clinical management and outcomes.

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Features of complexity were analysed in the context of the following high-risk groups: i) only CHA2DS2-VASc ≥2; ii) history of stroke/bleeding; iii) chronic kidney disease (creatinine clearance <60 mL/min, CKD); iv) frail (frailty index ≥0.25); v) ≥2 criteria. All these groups were compared to a low-risk group (CHA2DS2-VASc 0–1). We examined use of oral anticoagulant (OAC) and the risks of a composite outcome of all-cause death and major adverse cardiovascular events.

Results

A total of 10285 patients (mean [SD] age 68.8 [11.5] years, 4107 [39.9%] females) were included in the analysis. Of these, 3944 (38.3%) had only CHA2DS2-VASc ≥2; 412 (4.0%); history of stroke/bleeding; 1480 (14.4%) CKD; 1007 (9.8%) were frail; 1315 (12.8%) had ≥2 criteria; and 2127 (20.7%) were low-risk. After adjustment for age, sex, type of AF and EHRA score, compared to low-risk patients, all the other groups were associated with OAC prescription but with progressively lower odds ratio, while those ≥2 criteria which were least likely prescribed with OAC (Table 1).

After a mean (SD) 634.5 (223.0) days of follow-up, a total of 1432 events were recorded. After adjustment for confounders, Cox regression analysis found that all the complexity groups were associated with a higher risk of the composite outcome across the groups (Figure 1). In patients with available data about ABC (Atrial fibrillation Better Care) pathway adherence, the latter adherence was associated a significant incidence rate reduction (IRR) compared to non-ABC adherence in those with ≥2 criteria of clinical complexity (IRR 0.46, 95% CI 0.30–0.71), and in the CKD complexity group (IRR 0.57, 95% CI 0.41–0.81).

Conclusions

In a large contemporary cohort of European AF patients, features of clinical complexity affect differently prescriptions of OAC. All the subgroups of clinical complexity were associated with a higher risk of adverse outcomes, which were reduced by adherence to ABC pathway.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Since the start of EORP, the following companies have supported the programme: Abbott Vascular Int. (2011–2021), Amgen Cardiovascular (2009–2018), AstraZeneca (2014–2021), Bayer (2009–2018), Boehringer Ingelheim (2009–2019), Boston Scientific (2009–2012), The Bristol Myers Squibb and PfizerAlliance (2011–2016), The Alliance Daiichi Sankyo Europe GmbH and Eli Lilly and Company (2011–2017), Edwards (2016–2019), Gedeon Richter Plc. (2014–2017), Menarini Int. Op. (2009–2012), MSD-Merck & Co. (2011–2014), Novartis Pharma AG (2014–2020), ResMed (2014–2016), Sanofi (2009–2011), SERVIER (2010–2021), and Vifor (2019–2022).

Impact of the atrial fibrillation better care pathway in clinically complex patients with atrial fibrillation: a report from the ESC-EHRA EORP-AF General Long-Term Registry

Background

Clinical complexity is increasingly prevalent among patients with atrial fibrillation (AF). The “Atrial fibrillation Better Care” (ABC) pathway approach has been proposed to streamline a more holistic and integrated approach to AF care; however, there are limited data on its usefulness among clinically complex patients. We analyzed the impact of the ABC pathway in a contemporary cohort of clinically complex AF patients.

Methods

From the ESC-EHRA EORP-AF General Long-Term Registry, we analyzed clinically complex AF patients, defined as the presence of frailty (according to a 40-items Frailty Index), multimorbidity and/or polypharmacy. A K-medoids cluster analysis was performed to identify different groups of clinical complexity. The impact of an ABC-adherent approach on the risk of all-cause death, major adverse cardiovascular events (MACEs) and the composite outcome of all-cause death and MACE was analyzed through Cox-regression analyses, and delay of event (DoE) analyses; number needed to treat (NNT) was also estimated at 1 year of follow-up.

Results

Among 9,966 AF patients, 8,289 (92.3%) were clinically complex. Risk of all outcomes was higher among clinically complex patient. Adherence to the ABC pathway in the clinically complex group reduced the risk of all-cause death (adjusted HR [aHR]: 0.71, 95% CI 0.57–0.89), major adverse cardiovascular events (MACEs, aHR: 0.68, 95% CI 0.53–0.87) and composite outcome (aHR: 0.69, 95% CI: 0.57–0.84). Using cluster analysis, we identified a high clinical complexity group of AF patients. Adherence to the ABC pathway was associated with a significant reduction in the risk of death (aHR: 0.73, 95% CI 0.55–0.96) and composite outcome (aHR: 0.69, 95% CI 0.57–0.84) in the high-complexity cluster; similar trends were observed for MACEs. In DoE analyses, an ABC-adherent approach resulted in significant gains in event-free survival for all-cause death (Figure 1), MACEs, and composite outcome in clinically complex patients. Based on absolute risk reduction at 1 year of follow-up, the NNTs for ABC pathway adherence was 24 for all-cause death, 31 for MACEs and 20 for the composite outcome.

Conclusions

An ABC-adherent approach reduces the risk of major outcomes in clinically complex AF patients. Ensuring adherence to the ABC pathway is essential to improve clinical outcomes amongst clinically complex AF patients.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Since the start of EORP, several companies have supported the programme with unrestricted grants.

Factors associated with progression of atrial fibrillation and impact on all-cause mortality: an ancillary analysis from the ESC-EHRA EURObservational Research Programme in Atrial Fibrillation General

Background

Paroxysmal atrial fibrillation (AF) often shows a natural progression towards more sustained forms of the arrhythmia. Real-world data on clinical factors associated to AF progression and its impact on long-term outcome are limited.

Purpose

To investigate the factors associated with progression of AF and its impact on all-cause mortality in a contemporary cohort of European AF patients

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Patients with paroxysmal AF at baseline or first detected AF who underwent successful cardioversion were included. Patients with known rhythm status at 1-year were then stratified into two groups: (i) No AF progression and (ii) AF progression (as defined by transition to persistent or permanent AF). All-cause mortality at 2-year of follow-up was the primary outcome of the analysis.

Results

A total of 2688 patients were included (median age 67 years, interquartile range [IQR] 60–75, females 44.7%, CHA2DS2VASc score median 3 [1–4], HASBLED median 1 [1–2]). After 1-year of follow-up 2094 (77.9%) patients showed no AF progression while 594 (22.1%) developed AF progression. On multivariable logistic regression analysis, no physical activity (odds ratio [OR] 1.35, 95% confidence interval [CI] 1.02–1.78), valvular heart disease (OR 1.63, 95% CI 1.23–2.15), left atrium diameter (OR 1.03, 95% CI 1.01–1.05) and left ventricular ejection fraction (OR 0.98, 95% CI 0.97–1.00) were independently associated with AF progression at 1-year. At the end of 2-year of follow-up, death occurred in 80/2621 (3.1%) patients. Kaplan-Meier analysis showed a lower cumulative survival from all-cause mortality in patients with AF progression compared to non-progression AF patients (Log Rank p=0.01, Figure 1). On multivariable Cox regression analysis, adjusted for age, sex, heart failure, coronary artery disease, hypertensions, diabetes mellitus, previous thromboembolic events, peripheral artery disease, chronic kidney disease and use of oral anticoagulants, patients with AF progression had an independently higher risk for all-cause mortality (adjusted hazard ratio [aHR] 1.77, 95% CI 1.09–2.89).

Conclusions

In a contemporary cohort of European AF patients, a substantial number of patients progressed to sustained AF within 1 year. Clinical factors related to atrial structural remodeling were independently associated with arrhythmia progression. AF progression was associated with an increased risk of all-cause mortality.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Since the start of EORP, the following companies have supported the programme: Abbott Vascular Int. (2011–2021), Amgen Cardiovascular (2009–2018), AstraZeneca (2014–2021), Bayer (2009–2018), Boehringer Ingelheim (2009–2019), Boston Scientific (2009–2012), The Bristol Myers Squibb and Pfizer Alliance (2011–2016), The Alliance Daiichi Sankyo Europe GmbH and Eli Lilly and Company (2011–2017), Edwards (2016–2019), Gedeon Richter Plc. (2014–2017), Menarini Int. Op. (2009–2012), MSD-Merck & Co. (2011–2014), Novartis Pharma AG (2014–2020), ResMed (2014–2016), Sanofi (2009–2011), SERVIER (2010–2021), and Vifor (2019–2022).

Heart failure and cardiovascular outcomes in european patients with atrial fibrillation

Background

Heart failure (HF) has an intimate bidirectional association with atrial fibrillation (AF). Few data are available about the impact of HF phenotypes (HF with preserved ejection fraction, HFpEF; HF with mildly reduced ejection fraction, HFmrEF; HF with reduced ejection fraction, HFrEF) as predictors for adverse outcomes in AF patients.

Purpose

To investigate the association of HFpEF, HFmrEF and HFrEF with adverse outcomes in a large contemporary cohort of European AF patients and evaluate the effect of EF throughout its entire spectrum.

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. HF patients were categorized according the three phenotypes and compared to those without HF (“non HF”). Main outcome was a composite outcome of all-cause death and major adverse cardiac events (MACE).

Results

Among the original 11,096 AF patients enrolled, 9857 (88.8%) were included in this analysis (median age 71 years, interquartile range [IQR 63–77], 40.1% females) with median EF 55% [IQR 45–61%] and CHA2DS2-VASc 3 [2–4]). In this cohort, 5935 (60.2%) were non HF patients, and 3240 (32.9%) had HF patients (with HF status and EF values data available). Accordingly, 1662 (51.2%) were categorized as HFpEF; 523 (14.1%) were HFmrEF; and 1235 (35.1%) were HFrEF.

After a median follow-up of 731 days [IQR 690–748], the composite outcome was significantly higher throughout HF categories (HFpEF 19.0%, HFmrEF 21.8% and HFrEF 29.6%, compared to non HF 10.7%; p<0.001). In a fully adjusted multivariate Cox regression, HF phenotypes were associated with a progressively higher risk for the composite outcome (HFpEF HR 1.45 [95% CI, 1.23–1.70]; HFmrEF HR 1.82 [95% CI, 1.45–2.3]; HFrEF HR 2.51 [95% CI, 2.14–2.95], when compared to non HF patients). Considering EF in its continuous spectrum, an adjusted regression curve analysis found that progressively lower EF was associated with a progressively higher risk for the composite outcome, both in HF and overall AF patients (Figure 1, left and right panel, respectively).

Conclusions

Over a two-years follow-up, in a large contemporary cohort of European AF patients, HF phenotypes were associated with a progressively higher risk for adverse outcomes. Lower EF values increased the risk of adverse outcomes both in HF patients and overall AF patients, irrespective of HF phenotype status.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Since the start of EORP, the following companies have supported the programme: Abbott Vascular Int. (2011–2021), Amgen Cardiovascular (2009–2018), AstraZeneca (2014–2021), Bayer (2009–2018), Boehringer Ingelheim (2009–2019), Boston Scientific (2009–2012), The Bristol Myers Squibb and Pfizer Alliance (2011–2016), The Alliance Daiichi Sankyo Europe GmbH and Eli Lilly and Company (2011–2017), Edwards (2016–2019), Gedeon Richter Plc. (2014–2017), Menarini Int. Op. (2009–2012), MSD-Merck & Co. (2011–2014), Novartis Pharma AG (2014–2020), ResMed (2014–2016), Sanofi (2009–2011), SERVIER (2010–2021), and Vifor (2019–2022).

Thromboembolic risk dynamics, integrated care management and outcomes in patients with atrial fibrillation: a proof-of-concept analysis from the SPORTIF trials

Introduction

Few data exist on the impact of thromboembolic risk dynamics in determining a higher risk of adverse clinical outcomes in atrial fibrillation (AF) patients. Moreover, no evidence is available about the possible impact of integrated care, as defined by the `Atrial fibrillation Better Care' (ABC) pathway, in modulating the clinical outcomes associated with the dynamic changes in risk.

Purpose

To study thromboembolic risk dynamics and the relationship with integrated care, also in determining the risk of adverse outcomes in AF patients.

Methods

We analysed patients from the randomized controlled SPORTIF III and V trials. Thromboembolic risk was assessed according to CHA2DS2-VASc score. Integrated care was assessed according to ABC pathway adherence. The primary endpoint was the composite clinical outcome of all-cause death and major adverse cardiovascular events.

Results

A total of 3589 patients [mean (SD) age was 70.9 (8.8) years; 30.4% female; median [IQR] baseline CHA2DS2-VASc 3 [2–4]) were available for the analysis. Over a mean 573.8 (SD 129.5) days of follow-up, a total of 67 (1.9%) reported an increase in CHA2DS2-VASc score, with a mean (SD) delta of 0.0295 (0.2257). Among those with increasing CHA2DS2-VASc, 29 (43.3%) reported a 1-point increase, 37 (55.2%) reported a 2-point increase and only 1 (1.5%) reported a 3-point increase. A total of 948 (26.4%) patients were managed adherent to ABC pathway and overall, a median (IQR) of 2 [1–3] ABC criteria were fulfilled in the patients included. An adjusted linear regression analysis found that an increasing number of ABC pathway criteria fulfilled was inversely associated with increase in CHA2DS2-VASc score throughout follow-up (Beta −0.010, 95% CI −0.019 to −0.001), p=0.045), while considering the single ABC criteria, only the “C” criteria was inversely associated with an increase in CHA2DS2-VASc score (Beta −0.018, 95% CI −0.034 to −0.001, p=0.038). A total of 255 (7.1%) clinical events were recorded. An adjusted Cox regression analysis found that both increasing CHA2DS2-VASc score (HR 2.67, 95% CI 2.12–3.36, p<0.001) and increasing number of ABC pathway criteria fulfilled (HR 0.71, 95% CI 0.61–0.82) were independently associated with adverse outcomes. A regression line studying the interaction between increasing CHA2DS2-VASc, and ABC pathway adherence showed trends for improved risk reductions in clinical adverse outcomes when patients with increasing thromboembolic risk were managed according to integrated care [Figure 1].

Conclusions

Integrated care was associated with a lower progression in the thromboembolic risk of AF patients, particular through the optimal management of cardiovascular risk factors and comorbidities. Both increasing thromboembolic risk and increasing adherence to ABC pathway were independently associated, although inversely, with occurrence of adverse clinical outcomes.

Funding Acknowledgement

Type of funding sources: None.

684 Cardiac troponins and adverse outcomes in European patients with atrial fibrillation: a report from the ESC-EHRA EORP atrial fibrillation general long-term registry

Aims

Cardiac troponins (cTn) have been reported to be predictors for adverse outcomes in atrial fibrillation (AF), patients, but their actual use is still unclear. To assess the factors associated with cTn testing in routine clinical practice and to evaluate the association of elevated levels of cTn with adverse outcomes in a large contemporary cohort of European AF patients.

Methods and results

Patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry were stratified into three groups according to cTn levels as (i) cTn not tested, (ii) cTn in range (≤99th percentile), and (iii) cTn elevated (>99th percentile). The composite outcome of any thromboembolism/any acute coronary syndrome (ACS)/cardiovascular (CV) death, defined as major adverse cardiovascular events (MACE) and all-cause death were the main endpoints. 10 445 (94.1%) AF patients were included in this analysis [median age 71 years, interquartile range (IQR): 63–77; males 59.7%]. cTn were tested in 2834 (27.1%). Overall, cTn was elevated in 904 (8.7%) and in-range in 1930 (18.5%) patients. Patients in whom cTn was tested tended to be younger (P < 0.001) and more frequently presenting with first detected AF and atypical AF-related symptoms (i.e. chest pain, dyspnoea, or syncope) (P < 0.001). On multivariable logistic regression analysis, female sex, in-hospital enrollment, first-detected AF, CV risk factors, history of coronary artery disease (CAD), and atypical AF symptoms were independently associated with cTn testing. After a median follow-up of 730 days (IQR: 692–749), 957 (9.7%) composite endpoints occurred while all-cause death was 9.5%. Kaplan–Meier analysis showed a higher cumulative risk for both outcomes in patients with elevated cTn levels (Figure) (Log Rank tests, P < 0.001). On adjusted Cox regression analysis, elevated levels of cTn were independently associated with a higher risk for MACE [hazard ratio (HR): 1.74, 95% confidence interval (CI): 1.40–2.16] and all-cause death (HR 1.45, 95% CI: 1.21–1.74). Elevated levels of cTn were independently associated with a higher occurrence of MACE, all-cause death, any ACS, CV death and hospital readmission even after the exclusion of patients with history of CAD, diagnosis of ACS at discharge, those who underwent coronary revascularization during the admission and/or who were treated with oral anticoagulants plus antiplatelet therapy.

Conclusions

Elevated cTn levels were independently associated with an increased risk of all-cause mortality and adverse CV events, even after exclusion of CAD patients. Clinical factors that might enhance the need to rule out CAD were associated with cTn testing.

Implementation of cardiology tele-visits after COVID-19 pandemic: the INFO-COVID survey

Background

During the COVID-19 pandemic, implementation of telemedicine has represented a new potential option for outpatient care.

Purpose

The aim of our study was to evaluate digital literacy among cardiology outpatients.

Methods

From March to June 2020 a survey on telehealth among cardiology outpatients was performed. Digital literacy was investigated through six main domains: age; sex; educational level; Internet access; availability of Internet sources; knowledge and use of teleconference software programs.

Results

The study included 1067 patients, median age 79 years, 41.3% females. The majority of the patients (58.0%) had a secondary school degree, but among patients aged ≥75 years old the most represented educational level was primary school or none. Overall, for Internet access, there was a splitting between “never” (42.1%) and “every day” (41.0%), while only 2.7% answered “at least 1/month” and 14.2% “at least 1/week”. In the total population, the most used devices for Internet access were smartphones (59.0%), and WhatsApp represented the most used app (57.3%). Internet users were younger compared to non-Internet users (63 versus 78 years old, respectively) and with a higher educational level. Age and educational level were associated with non-use of Internet (age-per 10-year increase odds ratio [OR] 3.07, 95% confidence interval [CI] 2.54–3.71, secondary school OR 0.18, 95% CI 0.12–0.26, university OR 0.05, 95% CI 0.02–0.10) (Figure 1).

Conclusions

Telemedicine represents an appealing option to implement medical practice, and for its development it is important to address the gaps in patients' digital skills, with age and educational level being key factors in this setting.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Factors associated with Internet non-use

Impact of malignancy on outcomes in European patients with atrial fibrillation: a report from the ESC-EHRA EURObservational Research Programme in Atrial Fibrillation General Long-Term Registry

Background

Management of patients with atrial fibrillation (AF) and malignancy is a clinical challenge given the paucity of evidence supporting the appropriate clinical management.

Purpose

To evaluate the outcomes of patients with active or prior malignancy in a large contemporary cohort of European AF patients.

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. We stratified the population into three categories (i) No Malignancy (NoM) (ii) Prior Malignancy (PriorM) and (iii) Active Malignancy (ActM). The primary outcome for this analysis was all-cause death among the three groups. The association between anticoagulant treatment, all-cause death and haemorrhagic events was also evaluated.

Results

Among the original 11 096 AF patients enrolled, 10 383 were included in this analysis (median age 71 years (interquartile range [IQR] 63–77, males 59.7%). Of these, 9 597 (92.4%) were NoM patients, 577 (5.6%) PriorM and 209 (2%) ActM. Patients with malignancy (prior or active) had a higher median age, median CHA2DS2-VASc and HAS-BLED scores, compared to patients without malignancy (p<0.001). Lack of anticoagulation (AC) prescription occurred more commonly in ActM (21.5%) as compared with the other groups (PriorM 10.1% vs NoM 12.8%, p<0.001). In case of AC treatment, patients with ActM were treated more frequently with heparins (ActM 8.1% vs PriorM 2.4% vs NoM 2%, p<0.001).

After a median follow-up of 730 days [IQR 692–749], 982 (9.5%) patients died. Among all deaths, the proportion of cardiovascular death was different according to the three groups (40.0% in NoM, 26.0% in PrioM and 22.2% in ActM, p=0.002). For all cause-death, Kaplan-Meier analysis showed a progressively higher cumulative risk in the PriorM and ActM groups compared to NoM patients (Figure 1).

On multivariable Cox regression analysis, adjusted for CHA2DS2-VASc score, use of AC, type of AF and chronic kidney disease, ActM group was independently associated with a higher risk for all cause death (hazard ratio [HR] 2.90, 95% confidence interval [CI] 2.23–3.76) while PriorM group was not.

Among PriorM and NoM patients, multivariable adjusted Cox regression analysis found that the use of any AC was independently associated with a lower risk for all-cause death (HR 0.36, 95% CI 0.19–0.66; HR 0.66, 95% CI 0.54–0.81). No significant association between AC and all-cause death was found for ActM patients.

Conclusions

In a large contemporary cohort of European AF patients, active malignancy was found to be independently associated with all-cause death. Use of any AC was associated with a lower risk for all-cause death in patients with no malignancies and with prior malignancies, but with no significant association amongst patients with active malignancies.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Since the start of EORP, the following companies have supported the programme: Abbott Vascular Int. (2011–2021), Amgen Cardiovascular (2009–2018), AstraZeneca (2014–2021), Bayer (2009–2018), Boehringer Ingelheim (2009–2019), Boston Scientific (2009–2012), The Bristol Myers Squibb and Pfizer Alliance (2011–2016), The Alliance Daiichi Sankyo Europe GmbH and Eli Lilly and Company (2011–2017), Edwards (2016–2019), Gedeon Richter Plc. (2014–2017), Menarini Int. Op. (2009–2012), MSD-Merck & Co. (2011–2014), Novartis Pharma AG (2014–2020), ResMed (2014–2016), Sanofi (2009–2011), SERVIER (2010–2021), and Vifor (2019–2022). Figure 1. Kaplan-Meier for all-cause death

Epidemiology of subclinical atrial fibrillation in patients with cardiac implantable electronic devices: a systematic review and meta-analysis

Background

Sub-clinical atrial fibrillation (SCAF) and atrial high-rate episodes (AHREs), seen as high-frequency atrial tachyarrhythmias in patients with cardiac implantable electronic devices (CIEDs), have gained prominence as determinants of clinical atrial fibrillation (AF) and increased stroke risk. As a result, several studies investigating their role in predicting the onset of AF and AHRE-related outcomes have been conducted but uncertainty exists on the epidemiology of AHRE.

Purpose

To estimate the incidence of SCAF, according to presence of AHREs in patients with CIEDs, through a systematic review and meta-analysis of the available literature.

Methods

PubMed and EMBASE were searched from inception to 27th January 2021 for all studies documenting the incidence of AHREs in patients with CIEDs. We included all studies with ≥100 patients reporting data on AHREs incidence. Pooled prevalence and incidence rates were computed; we also performed meta-regressions for pooled incidence rates, according to relevant study-level characteristics. This study was registered in PROSPERO: CRD42019106994.

Results

Among the 2,515 results retrieved, we included 51 studies in the systematic review and meta-analysis, with a total of 68,414 patients. Meta-analysis of included studies showed a pooled prevalence of 28.2% (95% CI: 24.3–32.5%, I2=99%), with a pooled incidence rate (IR) of 15 new AHRE cases per 100 patient-years (95% CI: 12–19, I2=100%). Given the large heterogeneity showed in the pooled estimates we performed additional analyses. Regarding pooled prevalence, we performed several subgroup analyses, according to various studies baseline characteristics, which did not show any significant difference in any of the subgroups examined. Regarding IR, a multivariable meta-regression analysis showed that decreasing follow-up time and increasing age were the only factors significantly associated with AHRE incidence, explaining a large proportion of heterogeneity (R2=68%, p<0.001; Figure 1, Panel A and B respectively). Accordingly, the AHRE IR was highest at 1 year follow-up and in the oldest subjects. Presence of SCAF was significantly associated with older age, higher CHA2DS2-VASc score, and higher prevalence of hypertension, heart failure and history of cerebrovascular disease.

Conclusions

This systematic review and meta-regression demonstrated that SCAF is very common in patients with CIEDs, with an overall IR for AHREs of up to 15 per 100 patient-years; increasing with age and decreasing with longer follow-up time. Presence of SCAF was associated with an overall higher clinical risk profile compared to those subjects without SCAF.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Meta-regression for AHRE Incidence

Impact on outcomes in Europe: a cluster analysis from the ESC-EHRA EORP AF general long-term registry

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

ESC-EHRA EORP AF General Long-Term Registry Investigators

Introduction

Data derived from recent observational studies in atrial fibrillation (AF) show how the complexity of the clinical phenotype, beyond baseline thromboembolic risk, can increase risk of major adverse outcomes. Importantly, risk factors tend to occur in clusters, rather than occur individually in isolation.

Aims

To describe AF patients’ clinical phenotypes among a large contemporary European AF cohort and to analyse the differential impact of these clinical phenotypes on the occurrence of major adverse outcomes.

Methods

We performed a hierarchical cluster analysis based on Ward’s Method and using Squared Euclidean Distance using 22 clinical covariates. All variables were considered as binary. Examining the distances between cluster coefficients and by visual inspection of the dendrogram produced we identified the optimal number of clusters. Patients with data available for all 22 variables were included. We considered occurrence of cardiovascular events and all-cause death.

Results

Among the original 11096 patients included, 9363 (84.4%) were available for this analysis. The cluster analysis identified three clusters: Cluster 1 (n = 3634; 38.8%) characterized by older patients with prevalent noncardiac comorbidities; Cluster 2 (n = 2774; 29.6%) characterized by younger patients mainly admitted for first detected and paroxysmal AF with low prevalence of concomitant conditions; Cluster 3 (n = 2955; 31.6%) included patients with high prevalence of permanent AF, cardiac risk factors and comorbidities. Thromboembolic and bleeding risks were higher in Cluster 3 and progressively lower in Cluster 1 and Cluster 2 (both p < 0.001). Use of oral anticoagulant was significantly lower for Cluster 2 (83.2% vs. 86.5% and 86.7% in Cluster 1 and Cluster 3, respectively; p < 0.001). Over a mean follow-up of 22.5 (SD5.5) months, Cluster 3 had the highest rate of both cardiovascular events (10.0%) and all-cause death (13.2%), compared with Cluster 1 (6.6% and 9.4%, respectively) and Cluster 2 (3.7% and 3.8%, respectively) (both p < 0.001). Kaplan-Meier curves (Figure) show that Cluster 2 (green line) had the lowest cumulative risk of outcomes; risk was progressively higher in Cluster 1 (orange line) and Cluster 3 (yellow line). A Cox multivariable regression analysis, adjusted for type of AF, symptomatic status, CHA2DS2-VASc score and use of oral anticoagulants, showed that both Cluster 3 and Cluster 1 were associated with a significantly increased risk of cardiovascular events (HR: 1.80, 95%CI: 1.39-2.33 and HR: 1.40, 95%CI: 1.09-1.80, respectively) and all-cause death (HR: 1.80, 95%CI: 1.40-2.30 and HR: 1.66, 95%CI: 1.30-2.11) compared to Cluster 2.

Conclusions

In European AF patients, three main clinical clusters were identified, those with non-cardiac comorbidities, low risk and cardiac comorbidities. Both non-cardiac and cardiac comorbidities clusters were found to be associated with an increased risk of cardiovascular events and all-cause death. Abstract Figure. Kaplan-Meier Curves for Outcomes

Prevalence, management and impact of chronic obstructive pulmonary disease in atrial fibrillation: a systematic review and meta-analysis of 4,200,000 patients

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

AF-COMET Collaborative Group

Background

Multimorbidity is a major concern in patients with atrial fibrillation (AF). Among other diseases, the prevalence of chronic obstructive pulmonary disease (COPD) in these patients is unclear, and its association with adverse outcomes is often overlooked. Moreover, uncertainties on the treatment of patients with both AF and COPD still exist, and may lead to undertreatment.

Purpose

The aim of this study is to estimate the prevalence of COPD, and its impact on management and outcomes in patients with AF.

Methods

A systematic review and meta-analysis was conducted according to PRISMA guidelines. All studies reporting the prevalence of COPD in AF patients were included and pooled. Data on comorbidities, beta-blockers (BBs) and oral anticoagulant (OAC) prescription, and outcomes (all-cause death, cardiovascular death, ischemic stroke, major bleeding) were pooled and compared according to COPD status; the impact of BBs on outcomes in patients with COPD was also investigated. All analyses were performed using random-effect models; subgroup analysis and meta-regressions were also performed to account for heterogeneity.

Results

Among 46 studies, the pooled prevalence of COPD was 13% (95% Confidence Intervals (CI): 10-16%), with high heterogeneity between studies; significant differences were found according to geographical locations and definition of COPD. A multivariable meta-regression model which included age, female sex, history of hypertension, diabetes and chronic heart failure (CHF) was able to explain a significant proportion of the heterogeneity (R2 = 69.8%). COPD was associated with a higher prevalence of diabetes, coronary artery disease, CHF and stroke (Fig. 1, panel A), as well as higher CHA2DS2-VASc scores and age (Fig. 1, panel B), and lower probability of BB prescription (Odds Ratio (OR): 0.77, 95%CI: 0.61-0.98). Patients with COPD showed higher risk of all-cause death (OR: 2.22, 95%CI: 1.93-2.55), cardiovascular death (OR: 1.84, 95%CI: 1.39-2.43) and major bleeding (OR: 1.45, 95%CI: 1.17-1.80) (Fig.1, Panel C); no significant differences in outcomes were observed according to BBs use in AF patients with COPD (Fig. 1, panel D).

Conclusion

COPD is common in AF, being found in 1 every 8 patients, and is associated with an increased burden of comorbidities, differential management and worse outcomes, with more than two-fold higher risk of all-cause death and increased risk of CV death and major bleeding. Therapy with BBs does not increase the risk of adverse outcomes in these patients. Abstract Figure.

Factors affecting progression to permanent atrial fibrillation in an unselected population of patients with non-permanent form of atrial fibrillation

Background

Natural history of atrial fibrillation (AF) shows a progression of arrhythmia from non-permanent to permanent AF. Permanent AF was found associated with a worse prognosis than non-permanent one.

Aim

To assess the factors associated with progression to permanent AF in an unselected population of AF patients with non-permanent AF.

Methods

In this prospective study we enrolled in- as well as out-patients with non-permanent AF and age ≥18 years, with at least one episode of ECG-documented AF within 1 year. The patients were followed-up at 1 month and every 6 months thereafter.

Results

Out of 523 patients, 314 (60%) were in non-permanent AF (80 [25.5%] paroxysmal AF, 165 [52.5%] persistent AF, 69 [2%] first diagnosed AF), mostly male (188, 59.9%), median age 71 years (IQ range 62–77), median CHA2DS2VASc 3 (1–4), median HATCH score 1 (1–2). After a median follow-up of 701 (IQ range 437–902) days, 66 patients (21%) showed permanent AF.

CHA2DS2VASc and HATCH scores were incrementally associated to progression to permanent AF (CHA2DS2VASc χ2 p=0.001; HATCH χ2 p=0.017; p for trend CHA2DS2VASc <0.001, HATCH p=0.001).

At multivariable Cox proportional hazard regression the following variables were significantly associated with AF progression: age (hazard ratio [HR] 1.041; 95% CI: 1.004–1.079; p=0.028), at least moderate left atrial (LA) enlargement (>42 ml/m2) (HR 2.092; 95% CI: 1.132–3.866; p=0.018), antiarrhythmics drugs after the enrollment (HR 0.087; 95% CI: 0.011–0.662; p=0.018), EHRA score >2 (HR 0.351; 95% CI: 0.158–0.779; p=0.010) and Valvular HD (HR 2.161; 95% CI: 1.057–4.420; p=0.035). Adding LA dilation to HATCH score (HATCH-LA) and assigning 2 points based on multivariable Cox regression, HATCH-LA was statistically better in ROC curves in prediction of AF progression vs HATCH score (area under the curve 0.695 vs 0.636; DeLong p=0.0225). Survival-free curves on freedom from permanent AF using as discriminator HATCH-LA score ≤2 vs >2 led to a statistically significant difference (χ2=16.080 p<0.001), but the same was not found for HATCH score (χ2 =3.099; p=0.078).

Conclusions

In patients without permanent AF, progression of AF was independentely related to age, LA dilation, AF symptoms severity, antiarrhythmic drugs and Valvular HD. HATCH score predicted AF progression and adding to it LA dilation (at least moderate) improved patients stratification for the risk of evolution to permanent AF.

Funding Acknowledgement

Type of funding source: None

Impact of physical activity on all-cause mortality in European patients with atrial fibrillation: a report from the ESC-EHRA EORP AF General Long-Term Registry

Background

Physical activity (PA) may have a beneficial contribution for outcomes in patients with atrial fibrillation (AF).

Purpose

We aimed to evaluate the impact of self-reported PA in a large contemporary cohort of European AF patients on the risk of all-cause mortality.

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Self-reported PA was categorized, on the basis of reported time spent exercising, as follows: i) No PA; ii) Occasional PA; iii) Regular PA; iv) Intense PA. The primary outcome was all-cause death.

Results

Over 11096, a total of 8699 (78.4%) patients (mean age (SD) 69.1 (11.5); 40.7% female) had available data about PA and follow-up observation and were included in the analysis. Of these, 3703 (42.6%) reported no PA, 2829 (32.5%) occasional PA, 1824 (21.0%) regular PA, with only 343 (3.9%) reporting intense PA. With the 4 increasing PA categories, mean age, proportion of female patients, CHA2DS2-VASc and HAS-BLED scores were progressively lower (all p<0.001). Use of vitamin K antagonist (VKA) declined across the classes of PA (53.1% vs. 52.2% vs. 44.5% vs. 33.9%, p<0.001), while use of non-VKA OACs (NOACs) conversely increased. During a mean (SD) 680.6 (171.5) days of follow-up, there were a total of 848 (9.7%) all-cause death events. Based on Kaplan-Meier analysis, there was a progressively lower cumulative risk for all-cause death according to PA categories [Figure]. A multivariable Cox regression analysis, adjusting for CHA2DS2-VASc score, use of OAC at baseline and type of AF, found a lower risk of all-cause death associated with increasing levels of PA (Hazard ratio [HR]: 0.69, 95% confidence interval [CI]: 0.59–0.81 for occasional PA, HR: 0.45, 95% CI: 0.35–0.58 for regular PA, HR: 0.41, 95% CI: 0.23–0.76 for intense PA, when compared to no PA). In a sensitivity analysis, a regular-intense PA was inversely associated with occurrence of cardiovascular (CV) death, after multivariable adjustments for comorbidities (HR: 0.54, 95% CI: 0.37–0.77).

Conclusions

In a large contemporary cohort of European AF patients, self-reported PA was found to be inversely associated with all-cause death and CV death.

Kaplan-Meier Curves

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Since the start of EORP, several companies have supported the programme with unrestricted grants

Temporal changes in quality of life amongst European atrial fibrillation patients: relationship to all-cause mortality. A report from the ESC-EHRA EORP-AF General Long-Term Registry

Background

Atrial fibrillation (AF) significantly impacts on patients' quality of life (QoL). An impaired QoL has been associated with worse outcomes even in AF patients, but contemporary data in a large-scale pan-European population are limited.

Purpose

We aimed to assess temporal changes in AF patients' QoL across 2 years follow-up observation, and the relationship of QoL changes with all-cause death.

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. The EQ-5D-5L questionnaire was used to assess QoL. A Health Utility Score (HUS), indicating the overall health state (1 equals perfect health), was derived. Differences throughout the follow-up (Baseline, 1-Y FU, 2-Y FU) observation were assessed. The study outcome was all-cause mortality.

Results

Out of a total of 11906 patients, 8097 (73.0%) were available for this analysis. Mean (SD) age was 69.1 (11.5) years; 60.8% males; median CHA2DS2-VASc and HASBLED scores were 3 (IQR 2–4) and 1 (1–2), respectively. The mean (SD) HUS at baseline was 0.815 (0.200) and 0.834 (0.196), 0.829 (0.195) at 1-year follow-up and 2-year follow-up, respectively (p<0.0001 for changes over time). Patients with a higher CHA2DS2-VASc score (CHA2DS2-VASc 6–9) reported a significant reduction in the quality of life, compared to the other CHA2DS2-VASc strata, with a mean (SD) HUS decreasing from 0.754 (0.214) at baseline to 0.727 (0.238) at 2-year follow-up (F=6.538, p<0.0001) (Figure). Multivariate analysis demonstrated that age [−0.001 (95% CI [−0.002, −0.121]) and coronary artery disease (CAD) [−0.016 (95% CI [−0.029, −0.004] were independently inversely associated with increasing QoL. Positive changes in HUS over time were inversely associated with an increase in the risk of all-cause death, even after adjusting for chronic kidney disease, liver disease, chronic obstructive pulmonary disease, oral anticoagulants and type of AF (OR:0.24, 95% CI: 0.13–0.45 for increasing HUS difference, as a continuous variable).

Conclusions

In a contemporary European-wide cohort of AF patients, significant temporal changes in QoL were found. Patients at higher stroke risk according to CHA2DS2-VASc score showed a significant reduction in the QoL. Age and CAD were independently associated with changes in QoL. A greater reduction in HUS (i.e. worsening QoL) over time was associated with a higher risk of all-cause death.

Temporal changes in HUS

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Since the start of EORP, several companies have supported the programme with unrestricted grants

Relationship between frailty and all-cause mortality in patients with atrial fibrillation: a report from the ESC-EHRA EURObservational research programme AF general long-term registry

Introduction

Frailty is a major health determinant for cardiovascular disease. Thus far, data on frailty in patients with atrial fibrillation (AF) are limited.

Aims

To evaluate frailty in a large contemporary cohort of European AF patients, the relationship with oral anticoagulant (OAC) prescription and with risk of all-cause death.

Methods

We analyzed patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. A 38-items frailty index (FI) was derived from baseline characteristics according to the accumulation of deficits model proposed by Rockwood and Mitnitsky. All-cause mortality was the primary study outcome.

Results

Out of the 11096 AF enrolled patients, data for evaluating frailty were available for 6557 (59.1%) patients who have been included in this analysis (mean [SD] age 68.9 [11.5], 37.7% females). Baseline median [IQR] CHA2DS2-VASc and HAS-BLED were 3 [2–4] and 1 [1–2], respectively. At baseline, median [IQR] FI was 0.16 (0.12–0.23), with 1276 (19.5%) patients considered “not-frail” (FI<0.10), 4033 (61.5%) considered “pre-frail” (FI 0.10–0.25) and 1248 (19.0%) considered “frail” (FI≥0.25). Age, female prevalence, CHA2DS2-VASc and HAS-BLED progressively increased across the FI classes (all p<0.001). Use of OAC progressively increased among FI classes; after adjustments FI was not associated with OAC prescription (odds ratio [OR]: 1.09, 95% confidence interval [CI]: 0.98–1.19 for each 0.10 FI increase). Conversely, FI was directly associated with vitamin K antagonist (VKA) use (OR: 1.26, 95% CI: 1.18–1.34 for each 0.10 FI increase) and inversely associated with non-VKA OACs (NOACs) use (OR: 0.82, 95% CI: 0.77–0.88). FI was significantly correlated with CHA2DS2-VASc (Rho= 0.516, p<0.001). Over a median [IQR] follow-up of 731 [704–749] days, there were 569 (8.7%) all-cause death events. Kaplan-Meier curves [Figure] showed an increasing cumulative risk for all-cause death according to FI categories. A Cox multivariable analysis, adjusted for age, sex, type of AF and use of OAC, found that increasing FI as a continuous variable was associated with an increased risk of all-cause death (hazard ratio [HR]: 1.56, 95% CI: 1.40–1.73 for each 0.10 FI increase). An association with all-cause death risk was found across the FI categories (HR: 1.71, 95% CI: 1.23–2.38 and HR: 2.88, 95% CI: 2.02–4.12, respectively for pre-frail and frail patients compared to non-frail ones). FI was also predictive of all-cause death (c-index: 0.660, 95% CI: 0.637–0.682; p<0.001).

Conclusions

In a European contemporary cohort of AF patients the burden of frailty is significant, with almost 1 out of 5 patients found to be “frail”. Frailty influenced significantly the choice of OAC therapy and was associated with (and predictive of) all-cause death at follow-up.

Kaplan-Meier Curves

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Since the start of EORP programme, several companies have supported it with unrestricted grants.

P1517Risk of acute kidney injury in transcatheter aortic valve implantation procedures and impact on 30-day outcome

Background

Transcatheter aortic valve implantation (TAVI) is a safe and effective procedure for patients with symptomatic aortic stenosis who do not qualify for surgery. Nevertheless, post-procedure acute kidney injury (AKI) is a frequent complication and it is associated with worse outcomes.

Aim

To assess the impact of acute kidney injury (AKI) occurring immediately after the TAVI procedure on patients' outcome.

Methods

We conducted a multicenter retrospective study on patients treated with TAVI from 2010 to 2018. The assigned treatment, the selection of the device (self-expandable/balloon-expandable valve) and the type of approach used were determined by each individual Center on the basis of the patient's characteristics and the choice of the operator. All patients had an intermediate or high Society of Thoracic Surgeons (STS) score. Basal creatinine and glomerular filtrate (using the body mass index, sex and age) were evaluated for each patient. According to the KDIGO criteria, AKI is defined as an increase in serum creatinine (SCr) ≥0,3mg/dl within 48 hours or an increase in SCr ≥1.5 times baseline or urine volume <0,5ml/kg/h for 6 hours. The incidence of post procedural AKI and its correlation with the short-term mortality and outcomes was evaluated as primary end point (stroke/TIA/RIND, cardiac tamponade, bleeding, vascular complications, cardiocirculatory arrest with subsequent ROSC, definitive pacemaker implantation, postoperative atrial fibrillation, left bundle branch block de novo).Postoperative outcomes were defined according to the updated Valve Academic Research Consortium 2 definitions

Results

A total of 371 pts were analysed. Mean age was 82.3±5.9 and the majority of the pts had an STS score>10 (97.6%). Incidence of Acute kidney Injury (AKI) stage 3 post TAVI, according to VARC-2 criteria, was 16,2%. In patient with AKI, the hospitalization time was longer 18,7±6,1 days vs 8,4±6,1 days without AKI (p<0,01). Patients with AKI had an increased risk of in hospital mortality (OR 50,0; 95% CI 5,2–390,16; p<0,01) and 30 day mortality (OR: 5,88; 95% CI 2,08–16,60; p<0,01). Acute Kidney Injury instead was more common in patients treated with transapical access (OD 3,9-CI 95% 2,16–7,07; p<0,01) or with PAD (OR 1,87 - CI 95% 1,03–3,41; p=0,03)

AKI and short term mortality

Conclusion

Acute kidney injury is a frequent complication after TAVI. AKI seems to be the strongest predictor for 30 day mortality and increases the hospitalization time. AKI was more common in patients treated with a transapical approach or if they presented a PAD. In contrast, pre-procedural chronic kidney disease did not seem to correlate directly with an increased risk of AKI.

Transient bacteraemia due to Chryseobacterium indologenes in an immunocompetent patient: a case report and literature review

A 51-year-old woman was admitted to the emergency unit with diffuse headache, visus reduction, and paraesthesias of the trigeminal area and the left hand. Three days after admission she showed shaking chills, vomiting, and sudden onset of fever (39·4°C). Blood cultures were performed soon after fever onset. Fever persisted for the whole day, decreasing slowly after 12 hours. No empirical antibiotic treatment was started in order to better define the diagnosis. Fever completely disappeared the day after. Two blood cultures for aerobes were positive for Chryseobacterium indologenes. The patient was discharged with the diagnosis of transient bacteraemia and transferred to the neurology unit for further investigations. C. indologenes infections are described in 31 studies with a total of 171 cases (pneumonia and bacteraemia being the most frequent). Our case is the first report of transient bacteraemia caused by C. indologenes in an immunocompetent, non-elderly patient without needing medical devices.

[Antibiotic prophylaxis in day surgery in dermatology]

Antibiotic prophylaxis for the prevention of surgical wounds infections is still a matter of debate in dermatology. The authors have performed an open and randomized study on the prophylactic efficacy of azithromycin, 500 mg per os 1 h prior to the procedure in a dermosurgical office. The absence of postsurgical infections when the intervention has been executed in sites without risk of contamination both in the treated and no treated group, has demonstrated that, in the presence of correct prophylactic measures, no antibiotic prophylaxis is necessary. On the other hand, when the procedure has been performed in sites under risk of infection, the antibiotic prophylaxis has instead demonstrated a significant efficacy. The study has documented that azithromycin allows to efficacely prevent bacterical suprainfection with a good compliance of the patient in the cases in which dermosurgical activity is performed in sites with risk of infection (face, scalp, genitals, perineo, feet).

Batch xylitol production by Candida guilliermondii FTI 20037 from sugarcane bagasse hemicellulosic hydrolyzate at controlled pH values

Batch fermentation of sugarcane bagasse hemicellulosic hydrolyzate by the yeast Candida guilliermondii FTI 20037 was performed using controlled pH values (3.5, 5.5, 7.5). The maximum values of xylitol volumetric productivity ( Q(p)=0.76 g/l h) and xylose volumetric consumption ( Q(s)=1.19 g/l h) were attained at pH 5.5. At pH 3.5 and 7.5 the Q(p) value decreased by 66 and 72%, respectively. Independently of the pH value, Y(x/s) decreased with the increase in Y(p/s) suggesting that the xylitol bioconversion improves when the cellular growth is limited. At the highest pH value (7.5), the maximum specific xylitol production value was the lowest ( q(pmax)=0.085 g/l h.), indicating that the xylose metabolism of the yeast was diverted from xylitol formation to cell growth.

[Total implantable venous systems in day surgery]

Total implantable venous system (port-cath)in day surgery.

AIMS

Most of patients underwent to a total implantable venous system (port-cath) can be treated in day surgery.

METHODS

Since January 2000 to March 2003 we have implanted 31 port-a-cath, preferring access in subclavia v. We've treated all patients in day surgery and we've performed a Rx-control with a medium follow up of two hour.

RESULTS

We have not reported any early complication, only 3 late complications: a device malfunction, a "kinking" reservoir and an infection of the subcutaneous pocket. The last two complications have required the explantation of the device. In difficult catheterizations can be helpful to use a pediatric kit. The rules of an aseptic and antiseptic operative procedure and the utilization of a short term antibiotic prophylaxis can avoid infective complications. We have proposed, after the device implantation, cardioaspirina like preventive therapy of septic and no septic thrombosis. In the thrombotic occlusion of the catheter we propose the use of activase. In malfunction's prevention we propose a lateral placement (to the skin incision) of the subcutaneous pocket and a 45 degrees reservoir rotation.

CONCLUSIONS

The total venous system (port-cath) implantation can be mostly performed in day surgery, improving the compliance of the patients with a low cost procedure.

Preliminary kinetic characterization of xylose reductase and xylitol dehydrogenase extracted from Candida guilliermondii FTI 20037 cultivated in sugarcane bagasse hydrolysate for xylitol production

Candida guilliermondii FTI 20037 was cultured in sugarcane bagasse hydrolysate supplemented with 2.0 g/L of (NH4)2SO4, 0.1 g/L of CaCl2 x 2H2O, and 20.0 g/L of rice bran at 35 degrees C; pH 4.0; agitation of 300 rpm; and aeration of 0.4, 0.6, or 0.8 vvm. The high xylitol production (20.0 g/L) and xylose reductase (XR) activity (658.8 U/mg of protein) occurred at an aeration of 0.4 vvm. Under this condition, the xylitol dehydrogenase (XD) activity was low. The apparent K(M) for XR and XD against substrates and cofactors were as follows: for XR, 6.4 x 10(-2)M (xylose) and 9.5 x 10(-3) mM (NADPH); for XD, 1.6 x 10(-1)M (xylitol) and 9.9 x 10(-2) mM (NAD+). Because XR requires about 10-fold less xylose and cofactor than XD for the condition in which the reaction rate is half of the Vmax, some interference on the overall xylitol production by the yeast could be expected.

Effect of agitation and aeration on production of hexokinase by Saccharomyces cerevisiae

A batch culture of Saccharomyces cerevisiae for the production of hexokinase was carried out in a 5-L fermentor containing 3 L of culture medium, which was inoculated with cell suspension (about 0.7 g/L), and left fermenting at 35 degrees C and pH 4.0. The aeration and agitation were adjusted to attain k(L)a values of 15, 60, 135, and 230 h(-1). The highest hexokinase productivity (754.6 U/[L x h]) and substrate-cell conversion yield (0.21 g/g) occurred for a k(L)a of 60 h(-1). Moreover, the formation of hexokinase and cell growth are coupled events, which is in accordance with the constitutive character of this enzyme. Hexokinase formation for kLa > 60 h(-1) was not enhanced probably owing to saturation of the respiratory pathway by oxygen.

Extraction by reversed micelles of the intracellular enzyme xylose reductase

Xylose reductase enzyme (EC 1.1.1.21) produced by Candida guilliermondii in sugarcane bagasse was extracted by reversed micelles of N-benzyl-N-dodecyl-N-bis (2-hydroxyethyl) ammonium chloride cationic surfactant. An experimental design was employed to evaluate the influences of the following factors on the enzyme extraction: temperature, cosolvent, and surfactant concentration. A model was used to represent the enzyme recovery and fit of the experimental data. The extraction yielded a total recovery of 130%, and the purity increased 4.8-fold. This study demonstrates that liquid-liquid extraction by reversed micelles is a process able to recover and increase the enzymatic activity and purity of XR produced by C. guilliermondii.

Runt-related gene 2 in endothelial cells: inducible expression and specific regulation of cell migration and invasion

Understanding the regulation of endothelial cell (EC) gene expression has important implications for angiogenesis, tumor growth, and metastasis. The transcription factor runt-related gene 2 (RUNX2)/core binding factoralpha-1/acute myeloid leukemia 3/polyoma enhancer-binding protein 2alphaA/osteoblast-specific transcription factor 2 regulates osteoblast differentiation, increases lymphomagenesis in transgenic mice, and is expressed in murine ECs. Here, we report on RUNX2 expression in human bone marrow EC (HBME-1) and its role in EC differentiation. Expression of RUNX2 occurred in HBME-1 cultured on extracellular matrix (ECM) substrates that stimulate in vitro differentiation (tube formation). Neutralizing anti-insulin-like growth factor (IGF)-I-receptor antibody inhibited tube formation as well as activation of RUNX2 expression in HBME-1 cultured on ECM. IGF-I treatment also increased both RUNX2 mRNA and protein expression. HBME-1 transfectants expressing dominant-negative (DN) RUNX were established to address the role of RUNX2 in these processes. HBME/DN cells exhibited reduced tube formation activity relative to control transfectants and less ability to growth arrest and differentiate on ECM. DNRUNX expression also inhibited HBME-1 migration and invasion, which are necessary for tube formation. The urokinase-type plasminogen activator and membrane-type MMP-1 genes were consistently down-regulated in DNRUNX transfectants. The results suggest that RUNX2 is important in IGF-I and ECM-regulated EC migration and differentiation. RUNX2 effects on HBME-1 migration and invasion may occur through activation of protease expression, events that regulate angiogenesis, and tumor growth.

Effects of environmental conditions on xylose reductase and xylitol dehydrogenase production by Candida guilliermondii

The effects of environmental conditions, namely initial pH (2.5-7.0) and temperature (25 and 35 degrees C), on xylose reductase and xylitol dehydrogenase levels, as well as on xylitol production, were evaluated. Although the fermentative parameter values increased with an increase in pH and temperature (the maximum Yp/s and Qp were 0.75 g/g and 0.95 g/[L.h], respectively, both attained at pH 6.0, 35 degrees C), the highest xylose reductase activities (nearly 900 IU/mg of protein) were observed at an initial pH varying from 4.0 to 6.0. Xylitol dehydrogenase was favored by an increase in both initial pH and temperature of the medium. The highest xylitol dehydrogenase specific activity was attained at pH 6.5 and 35 degrees C (577 IU/mg of protein).

Adaptation and reutilization of Candida guilliermondii cells for xylitol production in bagasse hydrolysate

The xylitol productivity increased by about 15% with the use of cells of Candida guilliermondii FTI 20037 previously recycled through four consecutive batch cultures and adapted to the sugar cane bagasse hemicellulosic hydrolysate. Furthermore, the more concentrated the hydrolysate, the more necessary was the adaptation of the cells, owing to the presence of toxic substances at high concentration which inhibited the xylose-xylitol conversion by the yeast.

Use of immobilized Candida cells on xylitol production from sugarcane bagasse

In this study we used the yeast Candida guilliermondii FTI 20037 immobilized by entrapment in Ca-alginate beads (2.5-3 mm diameter) for xylitol production from concentrated sugarcane bagasse hemicellulosic hydrolysate in a repeated batch system. The fermentation runs were carried out in 125- and 250-ml Erlenmeyer flasks placed in an orbital shaker at 30 degrees C and 200 rpm during 72 h, keeping constant the proportion between work volume and flask total volume. According to the results, cell viability was substantially high (98%) in all fermentative cycles. The values of parameters xylitol yield and volumetric productivity increased significantly with the reutilization of the immobilized biocatalysts. The highest values of xylitol final concentration (11.05 g/l), yield factor (0.47 g/g) and volumetric productivity (0.22 g/lh) were obtained in 250-ml Erlenmeyer flasks containing 80 ml of medium plus 20 ml of immobilized biocatalysts. The support used in this study (Ca-alginate) presented stability in the experimental conditions used. The results show that the use of immobilized cells is a promising approach for increasing the xylitol production rates.

Characterization of invertase entrapped into calcium alginate beads

A solution of 10 g/L of sodium alginate (Satialgine types used [Sanofi trademark]: SG800 and S1100 with manuronic/guluronic ratio of 0.5 and 1.2, respectively) containing invertase (0.08 g of protein/L) was dropped into 0.1 M CaCl2 solution buffered at pH 4.0, 7.0, or 8.0. The beads were left to harden in CaCl2 solution for 24 h. The high immobilization yield of 60% occurred with SG800 at pH 8.0. The activity of soluble and insoluble invertase was measured against pH (2.8-8.0), sucrose concentration (4.5-45 mM), and temperature (30-60 degrees C). Both forms presented an optimum pH of 4.6. However, the soluble invertase was stable at the overall pH interval studied, whereas insoluble invertase lost 30% of its original activity at pH > 5.0. At temperatures above 40 degrees C, the insoluble form was more stable than the soluble one. The kinetic constants and activation energies (Ea) for free invertase were KM = 41.2 mM, Vmax = 0.10 mg of TRS/(min.mL), and Ea 28 kJ/mol for entrapped invertase they were (KM)ap = 7.2 mM, (Vmax)ap = 0.060 mg of TRS/(min.mL), and (Ea)ap = 24 kJ/mol.

A Preliminary Information About Continuous Fermentation Using Cell Recycling for Improving Microbial Xylitol Production Rates(Scientific Note)

Xylitol is a sugar-alcohol with important technological properties, such as anticariogenicity, low caloric value, and negative dissolution heat. It can be used successfully in food formulations and pharmaceutical industries. Its production is therefore in great demand. Biotechnological xylitol production has several economic advantages in comparison with the conventional process based on the chemical reduction of xylose. The efficiency and the productivity of this fermentation chiefly depends on the microorganism and the process conditions employed. In this article a simple continuous culture with cell recycling was evaluated to enhance the capability of Candida guilliermondii FTI 20037 to produce xylitol. The fermentation was initiated batchwise by directly inoculating the grown seed culture in a 2-L bench-scale fermentor. Continuous feeding was begun at a dilution rate (D) of 0.060/h after the xylose concentration had completely consumed and the cell concentration was about 4.0 g/L. At a dilution rate of 0.060/h the xylitol concentration was about 15 g/L and increased by about 35%, whereas the dilution rate decreased by about 58%. Furthermore, the volumetric productivity, Qp, markedly depended on the dilution rate, diminishing by about 37% as D was changed from 0.060 to 0.025/h. These preliminary results show us that continuous fermentation with cell recycling is a good way to study the xylitol production by xylose-fermenting yeasts.

Upstream parameters affecting the cell growth and xylitol production by Candida guilliermondii FTI 20037

The effects of yeast extract (0-10 g/l), methanol (0-10% v/v), acetic acid (0-1.0 g/l), furfural (0-0.5 g/l), glucose (0-30 g/l), inoculum age (15-70 h) and product concentration (18-230 g/l) on the xylose-xylitol conversion by Candida guilliermondii FTI 20037 were studied. The xylitol specific productivity increased about 35% at a yeast extract concentration of 1.0 g/l, whereas glucose showed a strong inhibitory effect on the xylitol production and a stimulating effect on the growth of C. guilliermondii. Methanol, acetic acid and furfural under the employed concentrations did not show any positive effect neither on the growth or on the xylose-xylitol conversion by the yeast. The inoculum age showed a strong influence on xylitol formation and the best fermentative parameters were attained using a 40-h inoculum age. A xylitol concentration in the fermentation medium higher than 80 g/l inhibited markedly the xylitol productivity by the yeast C. guilliermondii.

Hexokinase production from S. cerevisiae. Culture conditions

The effects of pH (4.0, 4.5, or 5.0), temperature (T) (30, 35, or 40 degrees C) and dissolved oxygen (DO) (0.2, 2.0, 4.0,or 6.0 mg O2/L) on hexokinase and invertase formation by yeast were studied. The highest enzyme activities were attained at pH 4.0, DO = 4.0 mg O2/L, and T = 35 or 40 degrees C.

Effect of pH, aeration and sucrose feeding on the invertase activity of intact S. cerevisiae cells grown in sugarcane blackstrap molasses

S. cerevisiae was grown in a blackstrap molasses containing medium in batch and fed-batch cultures. The following parameters were varied: pH (from 4.0 to 6.5), dissolved oxygen (DO) (from 0 to 5.0 mg O2 L-1) and sucrose feeding rate. When glucose concentration (S) was higher than 0.5 g L-1 a reduction in the specific invertase activity of intact cells (v) and an oscillatory behavior of v values during fermentation were observed. Both the invertase reduction and the oscillatory behavior of v values could be related to the glucose inhibitory effect on invertase biosynthesis. The best culture conditions for attaining S. cerevisiae cells suitable for invertase production were: temperature = 30 degrees C; pH = 5.0; DO = 3.3 mg O2 L-1; (S) = 0.5 g L-1 and sucrose added into the fermenter according to the equations: (V-Vo) = t2/16 or (V - Vo) = (Vf - Vo).(e0.6t-1)/10.

Effect of acetic acid on xylose fermentation to xylitol by Candida guilliermondii

The effect of acetic acid concentration on xylose-fermentation to xylitol by Candida guilliermondii FTI 20037 was evaluated in semisynthetic medium containing different concentrations of the acid. Increasing acetic acid concentration up to 1.0 g/l favored xylitol yield and productivity, with maximum values of 0.82 g/g and 0.57 g/l.h, respectively. The presence of acetic acid reduced cell production at all concentration. Furthermore, acetic acid was assimilated by the yeast together with the sugars and was depleted from the medium at concentrations of less than 3.0 g/l. The ability of this yeast to assimilate acetic acid suggests that these cells act as agents of medium detoxification. This behavior may lead to a viable microbiological process of xylitol production by C. guilliermondii FTI 20037 using xylose-rich lignocellulosic hydrolysates in which acetic acid is commonly present, causing inhibition of fermentative activity.

Effect of moisture content on the invertase activity of freeze-dried S. cerevisiae

The invertase activity of intact Saccharomyces cerevisiae submitted to freezing-thawing was affected by pH, the chemical nature of the buffer, and the freezing cooling rate (CR), leading in some cases to a complete invertase inactivation (acetate buffer, pH 4.0, CR = 0.5 degree C/min). Once established under adequate freezing conditions the invertase activity remained unchanged after freeze-drying. Nevertheless, in some cases the cell-growing capability after freeze-drying diminished around 70%, mainly if the frozen cell suspension was attained through freezing carried out at CR = 0.5 degree C/min. Water sorption isotherms of freeze-dried samples (freeze-dryer Edwards L-4KR; 30 degrees C and 0.1 mB) were determined at 10 and 25 degrees C. The monolayer moisture content (MMC) at each temperature (12.7 and 3.71 for 10 and 25 degrees C, respectively) was calculated from isotherms by applying BET and GAB models. Freeze-dried yeast with water activity (Aw) between 0 and 0.33 (about the MMC value) maintained at 25 degrees C for 235 days and at 89 degrees C for 15 min retained at least 85% of its original invertase activity (IA), whereas samples with Aw > MMC lost at least 60% of its IA. X ray diffraction showed that the freeze-dried cake before and after storage presented an amorphous structure.

Measurement of invertase activity of cells of Saccharomyces cerevisiae

The determination of the invertase activity of intact yeast cells presents a critical point, that is, the blockage of the enzyme action at a given moment. In this paper seven blockage methods were compared: the addition of 0.010 M sodium hydroxide solution, addition of 0.010 M sodium carbonate solution, addition of 0.010 M sodium carbonate solution followed by centrifugation (9750g; 10 min), immersion of the reacting mixture in a boiling water bath, immersion of the mixture in a -15 degrees C bath, filtration through a Millipore membrane, and addition of the first Somogyi's reagent followed by immersion in a boiling water bath. Only the last two methods lead to a rapid and effective blockage of the invertase activity.

[Variability of parameters in enzyme kinetics. 1. Intermethod oscillations]

Kinetic parameters of urease activity have been determined by five different methods, namely: Henry, Lineweaver-Burk, Hofstee, Woolf and Cornish-Eisenthal. In no instance different methods yielded the same values for the set of parameters (Km and Vmáx).