Prediction of programmed ventricular stimulation inducibility using machine learning in post-myocardial infarction patients at risk for sudden cardiac arrest with preserved ejection fraction ≥40%

Introduction

Sudden cardiac death (SCD) in post myocardial infarction (post-MI) patients with a relatively preserved left ventricular ejection fraction (LVEF ≥40%) has 1% annual incidence. In the PRESERVE-EF study, we used a two-step SCD risk stratification approach to detect patients with a relatively preserved left ventricular ejection fraction ≥40% at risk for major arrhythmic events. Seven noninvasive risk factors (NIRFs) were extracted from ambulatory electrocardiography. Patients with at least one NIRF present were referred for invasive programmed ventricular stimulation (PVS). Inducible patients received an ICD.

Purpose

The present study examines the performance of machine learning technology for the prediction of the inducible patients in PRESERVE-EF study.

Methods

After first step screening with NIRFs, 152 out of 575 patients underwent PVS and 41 of them were inducible. For the present analysis, data from these 152 patients were analysed. We used machine learning of NIRFs to predict these inducible high risk patients. We selected as classification method the Nearest Neighbour (NN) algorithm, after experimentation with several classifiers. NN classifies each subject according to the class of the N nearest neighbours. For each subject, we created a vector with the following 7 features: SAECG Late Potentials, Ventricular Premature beats ≥30/hour, Non-sustained Ventricular Tachycardia ≥1 episode (s)/24 hours, Fredericia corrected QT interval ≥45 0ms, SDNN/HRV ≤75 ms, T Wave Alternans ≥65 μV, Combined Deceleration capacity (DC) ≤4.5 ms and Heart Rate Turbulence Onset (To) ≥0% and Heart Rate Turbulence Slope (Ts) ≤2.5 ms.

Results

The achieved accuracy reached up to 72.2% when N was set to 7. We had totally 144 samples, 41 of which were inducible high risk patients. Results were similar for other values of N. To ensure independence of train and test sets, we employed 10-fold cross validation.

Conclusions

Inducible on PVS patients in PRESERVE-EF study were predicted with machine learning classification of NIRFs.

Funding Acknowledgement

Type of funding sources: None.

Prevention of radial artery spasm during coronary angiography with transdermal glyceryl trinitrate patches: the NURSE-TTS trial

Background/Introduction

One of the most common complications encountered during transradial procedures is radial artery (RA) spasm, whereas its management remains a challenge.

Purpose

We hypothesized that in patients undergoing cardiac catheterization via the RA, the use of transdermal nitroglycerin (NTG) patches applied to skin over the RA puncture site may prevent the occurrence of radial artery spasm.

Methods

NURSE-TTS (Nitrate Use to Obtain Radial Spasm Embarrassment) is a parallel-group, randomized, double-blind, placebo-controlled trial evaluating the impact of transdermal NTG application to RA spasm prevention. 146 patients were consecutively enrolled from February 2021 to December 2021 from an experienced center in Greece and underwent diagnostic coronary angiography. The primary endpoint was the exerting force of the RA measured by the dynamometer in Newton.

Results

The primary endpoint of the dynamometer measurements was found to be significantly different between the two groups. The treatment group's mean force was 5.95±2.60 and 7.21±2.82 for the placebo group respectively (p=0.007). The multivariate analysis confirmed that NTG patches affected radial spasm (treatment group p=0,010, 95% CI: −2,038, −0,282; age p=0,010, 95% CI: −0,099, −0,014; male gender p=0,011, 95% CI: −2,612, −0,349; CKD p=0,044, 95% CI: 0,064,0,951).

Conclusions

This is the first prospective randomized study demonstrating that the application of transdermal NTG 10mg on skin for 30 minutes before coronary angiography resulted in lower exerting force of the cannulated radial artery thus lower arterial spasm.

Funding Acknowledgement

Type of funding sources: None.

Long-term effects of phosphodiesterase-5 inhibitors on cardiovascular outcomes and death: a systematic review and meta-analysis of cohort studies

Background

Phosphodiesterase type 5 inhibitors (PDE-5i), which are widely used for the treatment of erectile dysfunction, have been found to exhibit systemic vascular benefits by improving endothelial function possibly lowering the risk for cardiovascular events and death.

Purpose

We sought to evaluate the effects of PDE5i on long-term cardiovascular outcomes and mortality.

Methods

A comprehensive search of electronic databases was conducted up to February 28, 2022. Cohort studies comparing PDE5i treatment at any dose with placebo or no treatment and a minimum follow-up duration of 6 months were considered eligible. The outcomes of interest were: (1) major adverse cardiovascular events (MACE) and (2) all-cause mortality. Pooled risk ratios (RR) with 95% confidence intervals (CI) were calculated.

Results

Eight trials were included (1,152,106 subjects, 8.5% treated with PDE5i). All were males [median age 61.5 years (range 30–72.8)]. The median follow-up duration was 3.8 years (range 2.3–7.5) across the studies. PDE5i use was associated with significant reduction in the composite of MACE [RR 0.79, 95% confidence intervals (CI) 0.69–0.91] (Figure 1). In addition, the analysis of pooled data from 5 studies, after removal of a study with a relatively small sample size, demonstrated that the use of PDE5i was associated with a significantly lower risk of all-cause mortality (RR 0.70, 95% CI 0.53–0.91) (Figure 2). Focusing on patients with a history of coronary artery disease, PDE5i was also found to reduce the risk of all-cause mortality by 15% (RR 0.85, 95% CI 0.74–0.98).

Conclusion

The use of PDE5i in men with or without known coronary artery disease was associated with a lower risk of cardiovascular events and overall mortality. This information underlines that PDE5i could provide considerable clinical benefit beyond the treatment of ED and could instigate the conduction of further, large-scale randomized clinical trials.

Funding Acknowledgement

Type of funding sources: None.

Stellate ganglion blockade for treatment of ventricular arrhythmia storm: a meta-analysis

Background

Autonomic neuromodulation and particularly stellate ganglion blockade (SGB) has been tested in ventricular arrhythmia (VA) storm, but there is so far no robust evidence to inform clinical practice and its use remains limited.

Purpose

We aimed to summarize the efficacy and safety of SGB in patients with VA storm.

Methods

We searched PubMed, the Cochrane Library and Scopus from inception to 15th March 2022, for studies performing either pharmacological or electrical SGB in the context of drug-refractory VA storm. Case series with less than 10 patients were excluded. We performed a single-arm random effects meta-analysis of studies to calculate the pooled proportion estimate of freedom from VA recurrence after SBG and the overall mean change of VA burden from baseline.

Results

Of 409 articles identified and screened, we considered eligible six studies comprising a total of 106 patients. The mean age was 61.6±13.9 years, 79.2% were male, the mean left ventricular ejection fraction was 28.8±12.7%, and 47.1% had underlying ischemic cardiomyopathy. In five trials the patients received pharmacological SGB with bupivacaine, ropivacaine, or/and lidocaine (left-sided or bilateral), while in one study transcutaneous magnetic stimulation of the left stellate ganglion was used. The pooled proportion of patients free of VA recurrences was 65% (95% CI 51–78%, I2=46%) at the first 24 hours post-SGB (Figure 1A), and 54% (95% CI 43–64%, I2=0%) at 72 hours (Figure 1B). The number of VA episodes was significantly reduced from a mean baseline of 7.01±8.34 episodes/24h before SGB to 0.93±1.64 episodes/24h after SGB. The mean absolute reduction of VA episodes was 5.44 (95% CI 2.83–8.05, I2=88%) (Figure 1C) while the mean absolute reduction of external or internal defibrillation events was 3.36 (95% CI 0.62–6.09, I2=84%) (Figure 1D). No serious procedure-related complications were reported. The overall in-hospital mortality was 28.4%.

Conclusions

SGB appears an effective and safe treatment in patients with VA storm with approximately 1 in 2 patients exhibiting complete suppression of VA for 72 hours and an approximately 80% mean relative reduction in VA burden.

Funding Acknowledgement

Type of funding sources: None.

Atrial high-rate episodes in patients with devices without a history of atrial fibrillation

Funding Acknowledgements

Type of funding sources: None.

Introduction

Atrial high-rate episodes (AHREs) recorded with cardiac implantable electronic devices (CIEDs) have been associated with the development of clinical atrial fibrillation (AF) and increase in stroke, and death risk.

Purpose

We sought to perform a systematic review with a meta-analysis to evaluate the prevalence of AHREs detected by CIEDs, their association with stroke risk, development of clinical AF, and mortality among patients without a documented history of AF.

Methods

We searched several databases, ClinicalTrials.gov, references of reviews, and meeting abstract books without any language restrictions up to 9 September 2020. We studied patients with CIEDs in whom AHREs were detected. Exclusion criteria were an AF history. Our primary outcome was the risk of ischemic stroke in patients with AHREs.

Results

We deemed eligible eight studies for the meta-analysis enrolling a total of 4322 patients with CIED and without a documented AF history. Evidence of moderate certainty suggests that patients with documented AHREs were 4.45 times (95% CI 2.87–6.91) more likely to develop clinical AF. Evidence of low confidence suggests that AHREs were associated with a 1.90-fold increased stroke risk (95% CI 1.19–3.05).

Conclusion

The present systematic review and meta-analysis demonstrated that among patients without a documented history of AF, the detection of AHREs by CIEDs was associated with significant increased risk of clinical AF and stroke.

Prognostic implications of valvular heart disease in patients with non-valvular atrial fibrillation

Background

Atrial fibrillation (AF) and valvular heart disease (VHD) are frequently encountered in clinical practice, and often coexist, especially in the elderly population. Both conditions are associated with increased mortality and morbidity. Recent guidelines suggest careful evaluation of patients with AF and VHD due to the puzzling nature of their coexistence.

Purpose

To evaluate the prognostic effect of significant valvular heart disease (sVHD) among patients with non-valvular AF.

Methods

This is a post-hoc analysis of the MISOAC-AF trial (NCT02941978). Consecutive inpatients with non-valvular AF who underwent echocardiography were included. sVHD was defined as the presence of at least moderate aortic stenosis (AS) or aortic/mitral/tricuspid regurgitation (AR/MR/TR). Cox regression analyses with covariate adjustments were used for outcome prediction.

Results

In total, 983 patients with non-valvular AF (median age 76 years) were analyzed over a median follow-up period of 32 months. sVHD was diagnosed in 575 (58.5%) AF patients. sVHD was associated with all-cause mortality (21.6%/yr vs. 1.6%/yr; adjusted HR [aHR] 1.55, 95% confidence interval [CI] 1.17–2.06; p=0.02), cardiovascular mortality (16%/yr vs. 4%/yr; aHR1.70, 95% CI 1.09–2.66; p=0.02) and heart failure-hospitalization (5.8%/yr vs. 1.8%/yr; aHR 2.53, 95% CI 1.35–4.63; p=0.02). The prognostic effect of sVHD was particularly evident in patients aged <80 years and in those without history of heart failure (p for interaction <0.05, in both subgroups) [Figure 1]. After multivariable adjustment, moderate/severe AS and TR were associated with mortality, while AS and MR with heart failure-hospitalization [Figure 2]. AS was the only independent predictor of valve intervention during follow-up (aHR 10.78, 95% CI 4.80–24.22; p<0.001). Mixed aortic valve disease (AS+AR) had superior prognostic power across patterns of combined VHD.

Conclusions

Among patients with non-valvular AF, sVHD was highly prevalent, and beared high prognostic value across a wide spectrum of clinical outcomes. AS, MR, TR and mixed aortic valve disease were associated with worse prognosis.

Funding Acknowledgement

Type of funding sources: None. Subgroup analyses by VHD statusPrognostic impact of valve lesions

Permanent pacemaker implantation in unexplained syncope patients with electrophysiology study-proven atrioventricular node disease

Funding Acknowledgements

Type of funding sources: None.

Background/Introduction: Syncope, whose cause is unknown after an initial assessment, has an uncertain prognosis. It is critical to identify patients at highest risk who may require a pacemaker and to identify the cause of recurrent syncope to prescribe proper therapy

Purpose

Aim of this study was to evaluate the effect of permanent pacing on the incidence of syncope in patients with unexplained syncope and electrophysiology study-proven atrioventricular node disease.

Methods

This was an observational study based on a prospective registry of 236 consecutive patients (60.20 ± 18.66 years, 63.1% male, 60.04 ± 9.50 bpm) presenting with recurrent unexplained syncope attacks admitted to our hospital for invasive electrophysiology study (EPS). Τhe implantation of a permanent antibradycardia pacemaker (ABP) was offered to all patients according to the results of the EPS. 135 patients received the ABP, while 101 denied.

Results

The mean of reported syncope episodes was 1.97 ± 1.10 (or presyncope 2.17 ± 1.50) before they were referred for a combined EP guided diagnostic and therapeutic approach. Over a mean follow-up of approximately 4 years (49.19 ±  29.58 months), the primary outcome event (syncope) occurred in 31 of 236 patients (13.1%), 6 of 135 (4.4%) in the ABP group as compared to 25 of 101 (24.8%) in the no pacemaker group (p < 0.001).

Conclusion

Among patients with a history of unexplained syncope, a set of positivity criteria for the presence of EPS defined atrioventricular node disease, identifies a subset of patients who will benefit from permanent pacing.

Arrhythmic risk stratification in heart failure mid-range ejection fraction patients with a non-invasive guiding to programmed ventricular stimulation two-step approach

Background

Although some post myocardial infarction (post-MI) and dilated cardiomyopathy (DCM) patients with mid-range ejection fraction heart failure (HFmrEF = 40–49%) face an increased risk for arrhythmic Sudden Cardiac Death (SCD), current guidelines do not recommend an implantable cardioverter-defibrillator (ICD).

Purpose

To assess the accuracy of a novel multifactorial two-step approach, with noninvasive risk factors (NIRFs) leading to programmed ventricular stimulation (PVS), for SCD risk stratification of hospitalized HFmrEF patients.

Methods

Forty-eight patients (male=83%, age = 64±14 years, LVEF = 45±5%, ischemic coronary disease = 69%) underwent a NIRF presence screening first step with ECG, SAECG, echocardiography and 24 hour ambulatory ECG (Holter). Thirty-two patients with presence of one out of three NIRFs (SAECG ≥2 positive criteria for late potentials, ventricular premature beats ≥240/24 hours, and ≥1 episode of non-sustained ventricular tachycardia on Holter) were further stratified with PVS. Patients were classified as either low (Group 1, n=16, NIRFs−), moderate (Group 2, n=18, NIRFs+ /PVS−) or high risk (Group 3, n=14, NIRFs+/PVS+). All Group 3 patients received an ICD.

Results

After 41±18 months, 9 out of 48 patients experienced the major arrhythmic event (MAE) endpoint (clinical ventricular tachycardia/fibrillation = 3, appropriate ICD activation = 6). The endpoint occurred more frequently in Group 3 (7/14, 50%) than in Groups 1 & 2 (2/34, 5.8%). A logistic regression model adjusted for PVS, age and LVEF revealed that PVS was an independent MAE predictor (OR: 21.152, 95% CI: 2.618–170.887, p=0.004). Kaplan Meier curves diverged significantly (p logrank <0.001) while PVS negative predictive value was 94%.

Conclusion

In hospitalized HFmrEF post-MI and DCM patients, a NIRFs leading to PVS two-step approach efficiently detected the subgroup at increased risk for MAEs.

Funding Acknowledgement

Type of funding source: None

Treatment of Early Vascular Ageing

Artery disease can be identified from ankle-brachial index (peripheral artery disease), pulse wave velocity (arterial stiffness), carotid intima media thickness (atherosclerosis) and flow-mediated dilation (endothelial dysfunction). Arterial stiffness is a marker of cardiovascular disease associated with cardiovascular events. Increased vascular ageing is the acceleration of arterial stiffness inappropriate for the given chronological age. Treatment of early vascular ageing seems to be important if we target primary cardiovascular prevention. Known factors that postpone the progression of vascular ageing may include lifestyle interventions such as physical exercise, moderate alcohol consumption, reduced salt consumption and weight reduction, factors that may preserve the vessels healthier than what expected for the chronological age. Hypertension, diabetes mellitus, obstructive sleep apnea and dyslipidemia are factors accelerating vessels damage and should be treated and maintained over time well controlled. In the future, trials are needed in order to identify the best combination of treatment as well as to identify drugs targeting on the vessels ageing.