Molecular typing of dengue virus in Mizoram, Northeast India

Introduction: Dengue is an emerging vector-borne public health threat and characterization at the molecular level is important for proper management of the disease. The aim of the study is to examine the diversity of the dengue viral serotypes from a hilly mountainous region of Northeast India. Methodology: Thirty-six blood samples that were positive for dengue virus IgM antibodies identified by the enzyme-linked immunosorbent assay (ELISA) method were collected and quantified for the IL6 gene expression by using reverse transcriptase polymerase chain reaction (RT-PCR). Results: All the patients had dengue hemorrhagic fever (DHF); 12 samples had a monotypic infection and 14 samples had dual infection with various dengue virus (DENV) serotypes; one sample had triple infection with DENV-1, DENV-2, and DENV-3. Conclusions: This study identified DENV-1 as the major serotype in the state of Mizoram and it is the first report on the molecular typing of the dengue virus from the hilly mountainous state located in the Indo-Burma region bordering Myanmar and Bangladesh.

Female sex and systolic blood pressure are independently associated with coronary microvascular dysfunction in asymptomatic adults with type 2 diabetes

Introduction

Coronary microvascular dysfunction is frequently reported in people with type 2 diabetes (T2D), is associated with reduced exercise capacity, and is a prognostic marker. Identifying modifiable risk factors associated with microvascular dysfunction may facilitate early intervention to improve outcomes in these patients.

Purpose

To identify independent determinants of myocardial perfusion reserve (MPR) in asymptomatic adults with T2D and no prevalent cardiovascular disease.

Methods

Prospective cross-sectional study. People with and without T2D and no signs, symptoms or evidence of cardiovascular disease underwent comprehensive phenotyping with echocardiography, coronary artery calcium scoring, and multiparametric cardiac MRI including adenosine stress and rest perfusion with automated pixel-wise myocardial blood flow (MBF) mapping. Participants with regional perfusion defects indicating obstructive coronary disease or silent myocardial infarct on late-gadolinium enhancement were excluded from analysis. Univariable and multivariable linear regression was performed to identify independent determinants of MPR.

Results

Two-hundred people with T2D (diabetes duration 11±8 years) were compared with 39 sex- and ethnicity-matched non-diabetic controls (Table 1). People with T2D had higher body mass index (BMI) and ambulatory 24-hour systolic blood pressure (SBP). There was evidence of concentric left ventricular (LV) remodelling (higher LV mass/volume), extracellular matrix expansion (higher ECV fraction), and both systolic and diastolic dysfunction (lower global longitudinal systolic strain and E/A ratio, respectively) in those with T2D. Resting MBF was similar between groups, but stress MBF tended to be lower in T2D compared to controls with significantly reduced MPR in T2Ds (2.87±0.86 vs 3.18±0.82, p=0.043). In univariable analysis, MPR correlated with sex, 24-hour SBP, and E/e' ratio. In a multivariable model adjusting for clinical (age, sex, smoking status, BMI, ambulatory SBP, diabetes duration, HbA1c, low-density lipoprotein, albuminuria) and imaging variables (E/e' ratio, LV mass/volume, global longitudinal strain, myocardial ECV, coronary calcium score) known to affect coronary perfusion, female sex (β=−0.227, p=0.013) and 24-hour SBP (β=−0.275, p=0.001) were the only variables independently associated with MPR.

Conclusion

Female sex is associated with coronary microvascular dysfunction in asymptomatic people with T2D but not LV mass or myocardial extracellular volume. Systolic BP is the only modifiable independent determinant of MPR and may be an early target for intervention to prevent heart failure development in these patients.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health Research (NIHR) United Kingdom through a Research Professorship award (RP-2017-08-ST2-007).British Heart Foundation through a Clinical Research Training Fellowship award (FS/16/47/32190).

Epicardial adipose tissue volume and density is associated with cardiac dysfunction in asymptomatic people with type 2 diabetes

Background

Type 2 diabetes (T2D) is associated with several perturbations of cardiac structure and function, which are precursors to the development of heart failure. Excess accumulation of epicardial adipose tissue (EAT) may contribute to cardiac dysfunction in individuals with T2D. Lipid-laden adipocytes have a lower computed tomography (CT) attenuation and can be readily identified using cardiac CT. Using a multimodality cardiac imaging approach, we aimed to assess the association of total and low attenuation EAT volume with early markers of cardiac dysfunction in people with T2D.

Methods

Prospective case-control study, in which participants with and without T2D and no known cardiovascular disease, underwent comprehensive cardiovascular phenotyping including multiparametric cardiac magnetic resonance imaging (MRI), echocardiography and non-contrast cardiac CT. EAT volume was measured from CT scans using a deep learning method and volumes indexed to body surface area. Total EAT was defined according to CT adipose tissue attenuation range of −30 to −190 Hounsfield Units (HU) and low attenuation EAT as −90 to −190 HU. Left ventricular (LV) volumes, function and strain measurements were derived from cardiac MRI images and diastolic function also assessed using echocardiography. Markers of early cardiac dysfunction in those with T2D were assessed for associations with EAT in T2D participants using multivariable linear regression analyses.

Results

Two hundred and fifty-four participants were included: demographic, anthropometric and imaging variables are displayed in Table 1. Subjects with T2D had increased LV concentric remodelling (higher LV mass/volume ratio), diastolic dysfunction (lower circumferential peak early diastolic strain rate (PEDSR) and average E/e') and reduced systolic function (global longitudinal strain, GLS) compared with controls. Total and low attenuation indexed EAT volumes were 1.6-fold and 2-fold higher, respectively, in participants with T2D compared to controls (Figure 1). After adjustment for age, gender, ethnicity, insulin resistance, systolic blood pressure and waist/hip ratio, total and low attenuation indexed EAT volume were independently associated with LV mass/volume ratio (total indexed EAT volume: β=0.002, p=0.02, low attenuation indexed EAT volume: β=0.004, p=0.01) and LV GLS (total indexed EAT volume: β=−0.02, p<0.01, low attenuation indexed EAT volume: β=−0.04, p=0.02) in subjects with T2D, but not indices of diastolic dysfunction.

Conclusion

Total and low attenuation EAT volumes are higher in individuals with T2D, and excess EAT accumulation is independently associated with early markers of cardiac dysfunction. Further studies into the underlying mechanisms of this interaction may facilitate the development of interventions targeted at EAT, which could mitigate against the development of heart failure in people with T2D.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): United Kingdom National Institute for Health Research

Differing approaches to analyse on-treatment cardiovascular events comparing daprodustat with darbepoetin: results from the ASCEND-ND trial

Background

Hypoxia-inducible factor prolyl hydroxylase inhibitors (HIF-PHIs) represent a potential new therapeutic option to treat anaemia of chronic kidney disease (CKD).

Purpose

In the recent ASCEND-ND trial (NCT02876835)1, conducted in patients with anaemia of CKD not requiring dialysis, the HIF-PHI daprodustat was non-inferior to darbepoetin for cardiovascular (CV) events in the primary intention-to-treat analysis (HR 1.03; 95% CI 0.89, 1.19); however, a prespecified on-treatment analysis raised concerns about a higher risk of CV events associated with daprodustat compared to darbepoetin (HR 1.40; 95% CI 1.17, 1.68). Our analysis explored potential reasons to explain the differences between on-treatment and intention-to-treat analyses in ASCEND-ND.

Methods

Overall, 3872 patients were randomised to receive either oral daprodustat (daily) or darbepoetin alfa given weekly, every 2 weeks, or every 4 weeks in an open-label fashion (last dosing frequency for darbepoetin was 7% weekly, 15% every 2 weeks, and 78% every 4 weeks). Patients were followed for development of the composite CV outcome (all-cause death, first non-fatal myocardial infarction, or first non-fatal stroke). The prespecified on-treatment approach included CV events up to 28 days following the last non-zero dose date of randomised therapy (Figure 1). Post-hoc analyses used Cox regression models to assess the impact of different follow-up periods (indexed to last non-zero dose date, treatment stop (discontinuation) date, and dosing intervals) on the treatment effect estimate.

Results

Different definitions of “on-treatment” using alternative censoring approaches resulted in hazard ratios for the CV composite outcome for daprodustat vs. darbepoetin that ranged from 1.06 (95% CI 0.89, 1.27) censored at treatment stop date; 1.09 (95% CI 0.89, 1.33) censored at last non-zero dose date + dosing interval; 1.54 (95% CI 1.20, 1.97) censored at the last non-zero dose date (Figure 2). As a result of the differential dosing interval, the gap between the last non-zero dose date and CV event date was 15 [1 to 134] days in the daprodustat arm, and 35 [13 to 134] days prior in the darbepoetin arm. This resulted in identical patients (i.e., identical treatment stop dates and event dates) being more likely to count as “on-treatment” in the daprodustat arm (Figure 1). This artefactual difference was not observed in analyses that were indexed to the treatment stop date, nor in analyses that accounted for the different dosing intervals for darbepoetin.

Conclusion

In the ASCEND-ND trial, different dosing frequencies introduced longer intervals between the last non-zero dose date and date of CV outcomes in the darbepoetin arm, compared with daprodustat. This artefact led to inappropriate undercounting of CV events in the darbepoetin arm. Accounting for the differential intervals resulted in neutral effect estimates, which were consistent with those observed with intention-to-treat approaches.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): ASCEND-ND was funded by GlaxoSmithKline

The AFLETES study: atrial fibrillation in veteran athLETEs and the risk of stroke

Background

Endurance athletes are at an increased risk of atrial fibrillation (AF) when compared to the general population. However, the risk of stroke in athletes who develop AF is not known.

Purpose

We aimed to assess the risk of stroke in endurance veteran athletes with AF when compared to those that remain in sinus rhythm.

Methods

A questionnaire was broadcasted through social media and sports clubs. Individuals that had competed in at least one competitive event and were ≥40 years old were included. Self-reported demographic, past medical history and training history data were collected and a CHA2DS2-VASc was calculated. Binary logistic regression was used to assess variables associated with AF and stroke.

Results

The survey received 1002 responses from 41 countries across Africa, Asia, Australasia, Europe, North and South America, and 942 were included in the final analysis. The average age was 52.4±8.5 years and 83.7% were male. The most common sports were cycling (n=677, 71.9%), running (n=558, 59.2%) and triathlon (n=245, 26%). There were 190 (20.2%) individuals who reported AF and 26 (2.8%) individuals who reported stroke, of which 14 (53.9%) had AF. Lifetime exercise dose (OR: 1.02, 95% CI: 1.00, 1.03, p=0.02) and swimming (OR: 1.56, 95% CI: 1.02, 2.39, p=0.04) were associated with AF in multivariable analysis. AF (OR: 4.18, 95% CI: 1.80, 9.72 p<0.01) was positively associated with stroke, even in individuals with a CHA2DS2-VASc of 0 or 1 (OR: 4.20, 95% CI: 1.83, 9.66, p<0.01) (Figure 1).

Conclusions

This survey provides early evidence that the risk of stroke in veteran endurance athletes who develop AF is not negligible, even in those deemed to be at low risk by CHA2DS2-VASc score. Longitudinal studies are needed to substantiate these findings to inform decisions around anticoagulation.

Funding Acknowledgement

Type of funding sources: None.

Transaortic flow rate to predict short and long term outcomes in individuals with asymptomatic aortic stenosis

Background

Echocardiographic derived transaortic flow rate (TFR), defined as stroke volume over left ventricular ejection time, has been shown to be associated with increased mortality in asymptomatic mild to severe aortic stenosis (AS) and superior to stroke volume index (SVi) in individuals with symptomatic discordant AS undergoing aortic valve replacement. However, TFR has not been explored alongside SVi in asymptomatic moderate to severe AS, who are a group of interest in risk stratifying for early intervention. Moreover, there is no data where TFR is indexed to body surface area (TFRi).

Purpose

We explored the prognostic value of TFR, TFRi and SVi in a homogenous cohort of asymptomatic patients with moderate to severe AS.

Methods

Subjects with asymptomatic moderate to severe AS were prospectively recruited to the Prognostic Importance of Microvascular Dysfunction in asymptomatic patients with AS (PRIMID) study, a multi-centre observational study in the UK conducted between April 2012 and November 2014. All subjects underwent extensive phenotyping with transthoracic echocardiography, bicycle exercise testing and cardiovascular magnetic resonance (CMR) imaging, with blinded core-lab analysis. Patients were followed up in person for a minimum of 12 months, and through health records thereafter. The composite outcome of interest was: cardiovascular mortality, AVR for symptoms and major adverse cardiovascular events (hospitalisation with heart failure, myocardial infarction, syncope and arrhythmia) at one-year and at five years. A cox proportional hazards model was used to calculate a hazard ratio (HR) and 95% confidence intervals (95% CI). Known co-variables associated with the composite outcome were added into the multivariable model.

Results

Overall, 173 individuals were included with a mean age of 66.3—-±13.3 years and 76.4% were male. Most individuals had severe AS (71.1%, n=123). There were 47 (64.4%) primary outcome events at one-year and 110 (63.6%) events at five-years. Age, sex, N-terminal pro brain natriuretic peptide (NT-pro-BNP), peak aortic velocity (AV Vmax), a positive exercise tolerance test (ETT), myocardial perfusion reserve and right ventricular ejection fraction measured on cardiac magnetic resonance were included in the multivariable model in addition to TFR or TFRi or SVi. Decreasing TFR and TFRi remained independently associated with one-year and five-year composite outcome (Figure 1). However, SVi was only associated with the composite outcome at five-years. AV Vmax (HR: 4.36, 95% CI: 2.59, 7.34, p<0.01) and a positive ETT (HR: 1.87, 95% CI: 1.03, 3.37, p=0.04) were independently associated with the primary outcome at one-year.

Conclusion

Both TFR and TFRi have a potential role in risk stratifying asymptomatic patients with AS and identifying those for earlier intervention, and may be superior to SVi. However, further prospectively designed studies are needed before this becomes part of the routine clinical practice.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Independent research from a Post-Doctoral Fellowship supported by the National Institute for Health Research (NIHR-PDF 2011-04-51 Geral P McCann).

Outcomes of additional substrate modification in de novo atrial fibrillation ablation

Background

Pulmonary vein isolation (PVI) is the cornerstone of atrial fibrillation (AF) ablation. Data regarding additional substrate modification has been conflicting, both in paroxysmal and persistent atrial fibrillation.

Purpose

To assess the effect of additional linear substrate modification during de novo AF ablation on AF recurrence.

Methods

We reviewed 1575 AF ablations in 1254 patients from January 2013 to June 2021 at a single academic medical center. There were 1096 de novo ablations. We defined substrate modification as linear ablations including cavotricuspid isthmus (CTI), superior vena cava isolation, intercaval line, mitral isthmus, and left atrial roof and floor lines. We evaluated clinical and procedural characteristics to identify risk factors for AF recurrence and complications. Patients were followed for a minimum of 6 months.

Results

The 1096 de novo ablations included 65.5% males with mean age 61.1 years, mean BMI 31.3, 81.8% paroxysmal AF and 18.2% persistent AF. There were four AF ablation subgroups: PVI alone (41.6%), PVI and CTI ablation (37.1%), PVI with CTI and additional substrate modification (15.6%), and PVI with substrate modification without CTI ablation (5.7%). Overall, AF recurred in 36.9% cases. AF recurrence with PVI only ablation was 41% compared to 32.7% in patients with PVI and CTI ablation (p=0.02). When looking at patients with paroxysmal and persistent AF, results were similar, with decreased AF recurrence with the addition of CTI ablation in both paroxysmal (37.3% v. 29.2%, p=0.03) and persistent AF (58.1% v. 40.0%, p=0.02). Additional substrate modification did not result in significant difference in outcome in either paroxysmal or persistent AF (Figure 1).

Conclusions

In de novo AF ablations, addition of CTI ablation to de novo PVI ablation is associated with lower AF recurrence in both paroxysmal and persistent AF. Additional linear substrate modification did not impact outcomes.

Funding Acknowledgement

Type of funding sources: None.

Inter-field strength agreement of left atrial assessment at 1.5T and 3T

Background

The agreement of left atrial (LA) volumetric and strain parameters between 1.5 and 3-tesla cardiovascular magnetic resonance (CMR) is not known. We aimed to investigate inter-field strength agreement of LA measurements in healthy volunteers scanned at both field strengths on the same day.

Methods

22 healthy volunteers were prospectively recruited and randomized to undergo scanning at either 1.5T or 3T first, immediately crossing over to the other field strength and scanned by the same radiographer. Steady-state free precession cines were analyzed blinded using Medis Suite. LA volumes and LA emptying fraction (LAEF) were calculated using the biplane area length method. LA strain (LAS) was assessed on 4- and 2-chamber and average values were calculated for LA reservoir, conduit, and booster pump function. Data were compared with paired t-tests and agreement was assessed by Bland-Altman plots and intra-class correlation coefficients (ICC).

Results

The median age was 32.5 (IQR 27.5, 42.5) and 45% were male. Key results are shown in the table and figure. There were no significant differences in the LA volumetric or strain mean values between 1.5T and 3T, although Bland-Altman analysis demonstrated a slightly positive bias at 1.5T for LAVmax, LAEF and LAS parameters. The inter-field strength agreement was excellent for LA volumes, reservoir and conduit strain (ICC >0.85, p<0.001), whilst LAEF showed good agreement (ICC=0.77, p=0.001). LAS at booster pump showed poor agreement, with the lowest ICC. The limits of agreement on Bland-Altman analysis were comparable for LAEF and LAS at reservoir.

Conclusion

There was excellent inter-field strength agreement for LA volumes, reservoir and conduit strain, suggesting that measurements can be used interchangeably between field strengths. Booster pump LAS had poor agreement, which is likely due to the fact that this measurement is less reproducible than volumes and reservoir/conduit LAS.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health Research (NIHR)

Safety of same day discharge after atrial fibrillation ablation

Background

Atrial fibrillation (AF) ablation is an outpatient procedure with traditionally an overnight hospital observation (OHO). Recently, there has been a trend towards same day discharge (SDD).

Purpose

Compare AF ablation procedure safety outcomes with SDD vs. OHO.

Methods

We reviewed consecutive AF procedures performed from January 2013 to June 2021 at a single academic center. Patients underwent OHO until June 2020, after which patients had SDD whenever feasible. Adverse events were assessed at three months, which included pericardial effusion, pericarditis, post-procedure hypotension, embolic events, and vascular complications. We also assessed emergency department (ED) visits and procedure-related hospital admissions.

Results

There were 1254 patients who underwent 1575 AF ablations. 1440 patients underwent OHO and 135 had SDD. Mean age was 62.2 years, BMI 33 kg/m2, 65% were male, and 27.6% had persistent AF, without significant differences in baseline characteristics between OHO and SDD. We found that SDD was not associated with increased complications (OHO 0.20% v. SDD 0.49%; p>0.05), ED visits, or hospital admissions (2% v. 5%; p>0.05) (Figure 1, 2). There were no gender or age-related disparities in all outcomes (p>0.05).

Conclusion

SDD protocol after AF ablation is feasible and not associated with higher incidence of complications, ED visits, and procedure-related hospitalizations.

Funding Acknowledgement

Type of funding sources: None.

Race disparities in atrial fibrillation detection using implantable loop recorder for cryptogenic stroke

Background

Cryptogenic stroke represents about 25–30% of all ischemic strokes. Continuous electrocardiographic monitoring using implantable loop recorder (ILR) can detect asymptomatic and undiagnosed atrial fibrillation (AF).

Purpose

To assess patient-specific factors in ILR implantation and AF detection in patients with cryptogenic strokes.

Methods

We retrospectively reviewed 379 patients with cryptogenic stroke indicated for ILR implantation, from January 2017 to June 2021 at our university hospital. We evaluated patient demographic and clinical characteristics to assess the risk factors associated with higher incidence of AF detection, using logistic regression models.

Results

Of the 379 ILRs implanted, 60.4% were males with 71.2% Caucasian, mean age 67.6 years, and mean BMI 28.5. The mean CHADSVASC score of 3.9 at the time of ischemic stroke. These patients had prior diagnosis of diabetes mellitus (27.4%), hypertension (65.7%), chronic kidney disease (19.5%), coronary artery disease (20%) and congestive heart failure (2%). Of the entire cohort, AF was diagnosed in 16% of patients with 14 months mean follow up. There were more females diagnosed with AF on ILR (20% v. 18.7%, p>0.05). Caucasians were more likely to have AF detected compared to non-Caucasians (OR 2.3, 95% CI, p<0.02). There were 52 patients with mobile cardiac outpatient telemetry (MCOT) before having ILR implantation. AF was not detected on MCOT, but 15% were diagnosed with AF with ILR monitoring. In univariate analysis, increasing age is strongly associated with the detection of AF (p=0.03).

Conclusions

There continues to exist race disparities in ILR implantation and eventual AF detection, leading to further socioeconomic health disparities. ILR should be considered especially in elderly with cryptogenic stroke given the higher incidence of AF detection.

Funding Acknowledgement

Type of funding sources: None.

Cardiovascular structure and function assessed by MRI in healthy South Asians compared to White Europeans: a UK Biobank study

Background

There is limited data on ethnic specific comparisons for measures of cardiovascular structure and function in healthy cohorts. Echocardiographic data indicate South Asian's (SAs) have smaller mass and evidence of more concentric remodelling compared to White Europeans (WEs). Furthermore, there is no data published for strain or strain rates.

Purpose

To compare Cardiac Magnetic Resonance (CMR) derived measures of structure and function between age and sex matched healthy SAs and WEs from the UK biobank cohort.

Methods

South Asian and WE participants from the UK Biobank who underwent CMR imaging were included. Individuals with a history of cardiovascular disease, hypertension, obesity (BMI ≥30 kg/m2 in WEs and ≥27 kg/m2 in SAs) and diabetes were excluded. Ethnic groups were matched according to age and sex at recruitment. Cine images (bSSFP) were analysed blinded to participant details using commercially available software. Left ventricular (LV) mass, LV volumes, global longitudinal and circumferential systolic strain (GLS and GCS), together with peak early diastolic strain rates (PEDSR), were obtained. Data distributions were assessed and T-Test or Man Whitney U conducted as appropriate.

Results

Datasets from the UK biobank were screened (n=45000). After applying exclusion criteria, 111 pairs of matched SAs and WEs were available for analysis (n=69 male and n=42 female matched pairs). Mean age of the entire cohort was 58±8 years. Data has been corrected according to body surface area (BSA),(males: WE 2.0±0.1 vs SA 1.8±0.1 m2, p≤0.001; females: WE 1.7±0.2 vs SA 1.6±0.1 m2, p≤0.001). There was no difference in heart rate (males: WE 64.5±9.3 vs SA 65.8±9.6 bpm, p=0.113; females: WE 66.2±7.8 vs SA 69.5±10.3 bpm, p=0.125). Results by sex and ethnicity are displayed in table 1. In males there was no difference in ejection fraction (EF) or indexed LV end diastolic volume (LVEDV). However indexed mass and mass/volume ratio were significantly lower in SAs, and GLS but not GCS was significantly higher than in SAs. Longitudinal PEDSR were significantly higher in SAs than in WE. By contrast, SA females had significantly lower EF with no difference in indexed LVEDV compared to WE females. However, as seen with the males SA females had significantly lower indexed LV mass and mass/volume ratio compared to WE females. Finally, both GLS and GCS were significantly higher in SAs compared to WE females, whereas there was no difference in longitudinal PEDSR.

Conclusion

Substantial differences in cardiovascular structure and function exist between SA and WE ethnic groups, in both men and women. Contrary to previous echocardiographic studies, LV volumes were similar between ethnicities and SA have less, not increased, concentric remodelling than WE. These findings highlight the need for ethnicity and sex-specific healthy reference ranges derived from CMR.

Funding Acknowledgement

Type of funding sources: None.

Effect of defibrillator on long term all-cause mortality in patients with chronic kidney disease: an updated meta-analysis

Background

The beneficial role of implantable defibrillator (ICD) in patients with chronic kidney disease (CKD) is less understood as this population is often not well represented in clinical trials.

Purpose

Evaluate the effect of ICD use in patients with CKD on long term outcomes.

Methods

Literature search was conducted for studies reporting the effect of ICD on all-cause mortality in patients with CKD, which is defined as glomerular filtration rate (GFR) <60 mL/min. The search was not restricted to time or publication status. The search included the following databases: Ovid MEDLINE, EMBASE, Scopus, Web of Science, Google Scholar, and EBSCO CINAHL. The minimum duration of follow-up required for inclusion was one year.

Results

The literature search identified 834 studies, of which 14 studies with 70,661 patients were included. Mean follow up was 39 months (12–81 months). For all patients with CKD, ICD was associated with lower all-cause mortality (log HR −0.247, SE 0.101, p=0.015); Heterogeneity: df=13 (P<0.01), I2=97.057; Test for overall effect: Z=−2.431 (Figure 1). When further stratified based on dialysis, CKD patients without the need for dialysis had favorable outcome (log HR −0.211, SE 0.095, p=0.026); Heterogeneity: df=6 (P<0.01), I2=70.146; Test for overall effect: Z=−2.225, whereas ICD implantation in CKD patients requiring dialysis was not associated with mortality benefit (log HR −0.262, SE 0.134, p=0.051) (Figure 2A, B).

Conclusion

ICD implantation is associated with mortality benefit in patients with CKD, but this association is not present for patients requiring dialysis.

Funding Acknowledgement

Type of funding sources: None.

Association of late-gadolinium enhancement in cardiac magnetic resonance with ventricular arrhythmias and mortality in patients with non-ischemic cardiomyopathy

Background

Late-gadolinium enhancement (LGE) in cardiac magnetic resonance (CMR) is a predictor of adverse events such as cardiovascular mortality, cardiovascular related hospitalization and defibrillation shocks in patients with non-ischemic cardiomyopathy (NICM). The correlation between LGE and ventricular arrhythmia and mortality has not been completely established.

Purpose

This meta-analysis assessed the relationship between LGE in CMR with ventricular arrhythmias: sustained, non-sustained and ICD therapy; and mortality in patients with NICM.

Methods

Databases were queried for studies reporting the association between LGE in CMR in NICM and ventricular arrhythmias and mortality, including Ovid MEDLINE, EMBASE, Web of Science, and Google Scholar. The search was not restricted to time or publication status. The minimal follow up duration was one year.

Results

A total of 46 studies and 10,548 patients (4,610 with LGE vs 5,938 without LGE) were included; mean follow up was 3 years (ranging between 13 to 71 months) and mean left ventricular ejection fraction 33%. LGE in NICM was associated with increased risk of ventricular arrhythmias and sudden cardiac death (odds ratio 4.595, 95% confidence interval 3.54–5.97; P<0.01) and mortality (odds ratio 2.949, 95% confidence interval 2.285–3.806; P<0.01). Heterogeneity is low to moderate: χ2=82.2, df =45 (P=0.001), I2=45% (Figures 1, 2).

Conclusions

Our results suggest that LGE is associated with increased risk of ventricular arrhythmias, sudden cardiac death and mortality in long-term follow up. These results further substantiate the need for larger prospective randomized trials using LGE to decide ICD indication regardless of EF. There are two ongoing trials testing this indication: CMR-ICD and CMR-GUIDE.

Funding Acknowledgement

Type of funding sources: None.

Does body mass index affect atrial fibrillation ablation outcomes

Background

There are conflicting reports in the literature regarding whether body-mass index (BMI) influences the success and procedural complication rates of atrial fibrillation (AF) ablation.

Purpose

To determine if differences in BMI affect AF ablation outcomes

Methods

At a single academic center, AF ablation procedures were reviewed from 2013 to 2021. Primary outcomes were AF recurrence (after a 90 day blanking period), procedure-related complications, emergency department visits or hospital admission (ED/HOSP). Patients had a minimum of 6 months follow-up

Results

We analyzed 1569 AF ablation consecutive procedures (1093 de novo, 476 repeat ablation) using either radiofrequency or cryoablation. The study population was 65% male with a mean age 62 years, with 28% persistent AF. BMI was separated into three cohorts: <25 kg/m2 (N=218), 25–30 kg/m2 (N=547), and >30 kg/m2 (N=804). There were no significant differences in the type of AF, left atrial diameter, or left ventricular ejection fraction in the BMI subgroups. There was a direct relationship between the prevalence of co-morbid conditions and increasing BMI: hypertension (49.1%, 59.9%, 60.2%; p 0.04), diabetes (6.4%, 13.5%, 21.3%; p 0.01), and obstructive sleep apnea (5.5%, 10.8%, 26.7%; p<0.01). There were no significant differences in AF recurrence, procedural complications or ED/HOSP among the BMI cohorts (p>0.05) (Figure 1). No gender related disparities were noted in outcomes (p>0.05).

Conclusion

Higher BMI was not associated with AF recurrence, complications, or ED/HOSP after AF ablation despite a higher prevalence of comorbid medical conditions

Funding Acknowledgement

Type of funding sources: None.

Inter-field strength agreement of cardiovascular magnetic resonance cine-derived strain and strain rate measures: a randomised study

Background

Left ventricular (LV) strain and strain rate measurements can be derived from routinely acquired cardiovascular magnetic resonance (CMR) cine images by feature tracking techniques. However, the inter-field strength agreement of strain measurements derived from these techniques is not known. We hypothesised that there would be excellent inter-field strength agreement (between 1.5 and 3 Tesla [T]) for the measurement of global strain and strain rate derived from cine imaging.

Methods

Prospective, randomised cross-over observational study. Healthy volunteers each underwent CMR scans at 1.5T and 3T within 30 minutes on the same day in a randomised order. Retrospectively ECG gated, short and long-axis balanced steady state free precession cine images were obtained using standardised acquisition parameters at both field strengths. Two software packages were used to derive LV global longitudinal, circumferential and long and short axis radial systolic strain, peak systolic, early diastolic and late diastolic strain rates. All strain values are expressed as positive numbers.

Results

Twenty-two subjects (mean age 36±12 years; 45% male) were studied. No differences in heart rate and blood pressure measurements during scanning were observed between field strengths. The abstract figure shows an example of strain analysis and Bland-Altman plots for global longitudinal and circumferential strain. Minimal bias was seen in all strain and strain rate measurements between field strengths using the first software package. Strain and strain rate values derived from long axis images (longitudinal and long axis radial) showed poor to fair agreement (intraclass correlation co-efficient (ICC) range 0.39–0.71), whereas measures derived from short axis images (circumferential and short axis radial) showed good to excellent agreement between field strengths (ICC range 0.78–0.91). Similar results were observed with the second software package, though the differences in agreement between long and short axis derived measures were less pronounced.

Conclusion

Longitudinal strain and strain rate measures derived from CMR feature tracking have poor inter-field strength agreement between 1.5T and 3T. By contrast, agreement of circumferential and short axis radial strain and strain rate measurements at 1.5T and 3T is good. These results need to be considered when assessing strain at different field strengths.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): United Kingdom National Institute for Health Research

Impaired myocardial calcium handling in people with type 2 diabetes: an in vivo manganese-enhanced magnetic resonance imaging study

Background

There is a high prevalence of subclinical cardiac dysfunction in people with type 2 diabetes (T2D) which is associated with subsequent development of heart failure. Dysregulated myocardial calcium handling has been demonstrated in animal models of T2D and may be a key mechanism driving the development of heart failure. Manganese-enhanced cardiac magnetic resonance imaging (MEMRI) provides a unique method to assess in vivo myocardial calcium handling.

Purpose

To determine whether myocardial calcium handling is perturbed in people with T2D with no history of cardiovascular disease. We hypothesised that myocardial manganese uptake would be reduced in people with T2D compared with healthy volunteers.

Methods

Cross-sectional case-control study, adults with (n=20) and without (n=9) T2D underwent both gadolinium-enhanced MRI and MEMRI. Standard gadolinium-enhanced MRI was used to assess cardiac structure, function and tissue characteristics. MEMRI scans were performed within two weeks of the initial scan. Native T1 maps were obtained in the mid-short axis slice position using a Modified Look-Locker Inversion recovery sequence. An intravenous infusion of manganese dipyridoxyl diphosphate (5 μmol/kg (0.1 mL/kg) at 1 mL/min) was administered and T1 maps at the same location were repetitively acquired every 2.5 min for 30 min. Regions of interest were drawn in the inferoseptal segment and blood pool for all T1 maps from 0 to 30 min by a single observer. The primary outcome was the rate of manganese uptake which was assessed by Patlak modelling as a measure of myocardial calcium handling. Manganese uptake constants were compared using analysis of co-variance, with age, sex and body mass index as co-variates.

Results

Subjects with T2D were older (62±7 vs. 57±5 years, p=0.046) but body mass index (29.0±4.5 vs. 26.2±3.4 kg/m2, p=0.106), systolic (135±16 vs. 134±17 mmHg, p=0.809) and diastolic (81±10 vs. 83±9 mmHg, p=0.736) blood pressures were similar. Compared to control subjects, participants with T2D had normal systolic function but more concentric left ventricular remodelling (mass/volume ratio 0.90±0.14 vs. 0.71±0.06 g/mL, p<0.001) and reduced peak early diastolic strain rate (0.64±0.17 vs. 0.91±0.26 s–1, p=0.002). Myocardial manganese uptake was substantially reduced in people with T2D compared with controls (6.51±1.46 vs. 8.45±2.52 ml/100 g of tissue/min, p=0.003) (Figure 1).

Conclusions

For the first time, we have demonstrated in vivo that despite no history of cardiovascular disease and normal systolic function, patients with T2D have marked impairment of myocardial calcium handling. This has potential major implications for the pathogenesis, diagnosis and treatment of diabetic cardiomyopathy.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation and National Institute for Health Research

The influence of anastomotic techniques on postoperative anastomotic complications: Results of the Oesophago-Gastric Anastomosis Audit

BACKGROUND

The optimal anastomotic techniques in esophagectomy to minimize rates of anastomotic leakage and conduit necrosis are not known. The aim of this study was to assess whether the anastomotic technique was associated with anastomotic failure after esophagectomy in the international Oesophago-Gastric Anastomosis Audit cohort.

METHODS

This prospective observational multicenter cohort study included patients undergoing esophagectomy for esophageal cancer over 9 months during 2018. The primary exposure was the anastomotic technique, classified as handsewn, linear stapled, or circular stapled. The primary outcome was anastomotic failure, namely a composite of anastomotic leakage and conduit necrosis, as defined by the Esophageal Complications Consensus Group. Multivariable logistic regression modeling was used to identify the association between anastomotic techniques and anastomotic failure, after adjustment for confounders.

RESULTS

Of the 2238 esophagectomies, the anastomosis was handsewn in 27.1%, linear stapled in 21.0%, and circular stapled in 51.9%. Anastomotic techniques differed significantly by the anastomosis sites (P < .001), with the majority of neck anastomoses being handsewn (69.9%), whereas most chest anastomoses were stapled (66.3% circular stapled and 19.3% linear stapled). Rates of anastomotic failure differed significantly among the anastomotic techniques (P < .001), from 19.3% in handsewn anastomoses, to 14.0% in linear stapled anastomoses, and 12.1% in circular stapled anastomoses. This effect remained significant after adjustment for confounding factors on multivariable analysis, with an odds ratio of 0.63 (95% CI, 0.46-0.86; P = .004) for circular stapled versus handsewn anastomosis. However, subgroup analysis by anastomosis site suggested that this effect was predominantly present in neck anastomoses, with anastomotic failure rates of 23.2% versus 14.6% versus 5.9% for handsewn versus linear stapled anastomoses versus circular stapled neck anastomoses, compared with 13.7% versus 13.8% versus 12.2% for chest anastomoses.

CONCLUSIONS

Handsewn anastomoses appear to be independently associated with higher rates of anastomotic failure compared with stapled anastomoses. However, this effect seems to be largely confined to neck anastomoses, with minimal differences between techniques observed for chest anastomoses. Further research into standardization of anastomotic approach and techniques may further improve outcomes.