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.

Optimization of biventricular cardiac resynchronization improves cardiac power and atrial kinetics in patients with systolic heart failure with often hospitalizations for decompensation

 

Cardiac resynchronization therapy (CRT) reduces symptoms and improves left ventricular function in patients with heart failure due to left ventricular systolic dysfunction and cardiac dyssynchrony. In this work the biochemical, clinical and echocardiographic outcome of optimizing CRT (optCRT) function by the optimal VTI value of left ventricular outflow track.

Methods

80 NYHA III patients (68±10 years; 75% men; 53% ischemic cardiomyopathy-ICM), under optimal tolerated medical therapy, with standard BVP indication, having been implanted with a CRT system. Echocardiographic measurements, including aortoventricular coupling (VAC) calculation, 6-min-walking-test and quality of life (MLHF questionnaire) were measured at baseline, 6 months on optCRT. Cardiac power (CP) was calculated according the equation: CP=Cardiac Output x Mean Aortic Pressure/451.

Results

End-systolic volume of left ventricle was reduced (p=0.001) in both ischemic and non-ICM; while max left atrial volume was reduced only in non-ICM patients (72.1±32 to 65.8±30, p=0.04). Global longitudinal strain was improved in non ICM patients (p=0.015). Systolic strain of right ventricle was improved in non-ICM (9.4±2.2 to 10.7±2.3 vs. 8.7±3 to 8.9±3.2, p=0.03 for non-ICM); while left atrial function and the ratio E to E TDI of mitral annulus were not improved in either group. Non-ICM patients improved VAC (baseline: 1,36±0,3; CRT: 1.11±0.2; p=0.01) and CP (baseline 660±160 to 782±260, p=0.001); while no significant improvement was detected to ICM patients. 6-min-walk test was improved up to 30% (p=0.05). NtproBNP levels were decreased only in non-ICM patients (1759±1060.9 to 1015±650 vs. 2063,8±1800 to 1950.7±2342, p=0.001). MLHFQ improved in non-ICM patients (p=0.015); while non-significant improvement was detected in ICM patients.

Conclusion

Optimization of cardiac resynchronization therapy based on stroke volume maximization benefits quality of life and exercise tolerance, mainly in non-ICM. GLPS and aorto-ventricular coupling was improved in non-ischemic patients, reflecting the better adaptation of CRT in this population. Thus, CRT optimization by echocardiographic evaluation may be useful in improve clinical status and quality of life in CRT non-responder patients.

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.

Multipoint left ventricular pacing effects on hemodynamic parameters and functional status: HUMVEE single-arm clinical trial

Objectives

The aim of this study was to assess the capacity of optimized multipoint pacing (MPP) over optimized cardiac resynchronization therapy (CRT), in terms of clinical, functional, and echocardiographic parameters among dyssynchronous heart failure patients.

Methods

Eighty patients (Caucasian, 77.5% male, 68.4±10.1 years, 53.8% ischemic cardiomyopathy) sequentially received optimized CRT and optimized MPP over 6 and 12-month periods, in a single-arm clinical trial. Clinical, laboratory and echocardiographic assessment was conducted at baseline and following completion of each step.

Results

Significant additive effects of optimized MPP over optimized CRT were noted regarding 6-minute walking distance (baseline/optCRT/optMPP: 293±120m vs 367±94m vs 405±129m, p<0.001), NYHA class (2.36 vs 2.19 vs 1.45, p<0.001), VTIlvot (14.25±3.2cm vs 16.2±4cm vs 17.5±3.4cm, p<0.001), stroke volume (48±13.5ml vs 55±15ml vs 59±15ml, p<0.001), LVEF (29%±7.1% vs 33%±7.3% vs 37%±7.7%, p<0.001), maximal left atrial volume (77.2±34.2ml vs 74.2±39.5ml vs 67.7±32ml, p=0.02), pulmonary artery systolic pressure (35.9mmHg vs 33.5mmHg vs 31mmHg, p<0.001), and right ventricular strain (−8.3%±6.9% vs −8.8%±6.6% vs −11.8%±6.1%, p=0.022). Regarding VAC SW and CP as percentages of maximal, there was significant difference detected compared to baseline for both CRT and MPP. Additive effects persisted only if suitable MPP dipoles were present. Exploratory analysis revealed that ischemic cardiomyopathy continued to exhibit significant differences favoring MPP, whereas nonischemic cardiomyopathy had similar findings regarding total left atrial strain and quality of life.

Conclusions

Optimized MPP showed significant improvements on hemodynamic parameters and ventricular function, in heart failure patients over optimized CRT. The beneficial effect was more prominent in men and in those with rather reduced LVEF, consistent with findings suggesting a beneficial trend in VAC and CP with the more homogenous depolarization offered by optimized MPP

Funding Acknowledgement

Type of funding sources: None.

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.

Noninvasive risk factors for the prediction of inducibility on programmed ventricular stimulation in post-MI patients with ejection fraction over 40% at SCD risk, insights from the PRESERVE EF study

Funding Acknowledgements

Type of funding sources: None.

Background

Sudden cardiac arrest (SCA) in post myocardial infarction (post-MI) patients with a relatively preserved left ventricular systolic function (LVEF≥40%) has an annual incidence of 1%, in the absence of adequate risk stratification methods and guideline recommendations for primary prevention. In the PRESERVE-EF study we used a two-step SCA risk stratification approach to detect patients at risk for major arrhythmic events. Seven noninvasive risk factors (NIRFs) were extracted from ambulatory electrocardiography (AECG). Patients with at least one NIRF present were referred for invasive programmed ventricular stimulation (PVS). Inducible patients received an ICD.

Purpose

To assess the performance of NIRFs extracted from 24hr AECG, based on the PRESERVE EF criteria, in predicting inducibility.

Methods

The PRESERVE EF study enrolled 575 patients. Two hundred and four of them had at least one NIRF and an indication for PVS, but 52 of them declined. Finally, 41 out of 152 patients who underwent PVS were inducible. For the present analysis data from these 152 patients (mean age 60 ± 10years, LVEF 49 ± 6%, 89% males) were analyzed. Chi-square test, univariate logistic regression and areas under ROC curves were calculated for the PVS inducibility endpoint.

Results

Age, male gender and LVEF for the PVS inducible patients group (n = 41) and the noninducible patients group (n = 111) were, respectively: 61 ± 9years vs 59 ± 10years (p = 0.310), 98% vs 86% (p = 0.048), 45 ± 4% vs 51 ± 7% (p < 0.001). Among NIRFs examined, LVEF ≤ 50%, nsVT≥1/24hour and presence of LPs on SAECG presented high and significant Odds Ratios (ORs) for a positive PVS study end point. A simple risk score based on cutoff points of LVEF ≤ 50%, NSVTepisode≥1/24hour and presence of LPs missed only 1 out of the 41 inducible patients and yielded: OR 14.146 (p = 0.01) with a high sensitivity 98% but low specificity 26% for a positive PVS (AUC = 0.65).

Conclusion

Cut off points of LVEF ≤ 50%, nsVTepisode≥1/24hour and presence of LPs were important predictors of inducibility. A simple risk score based on these predictors achieves high sensitivity but low specificity.  The final decision for an ICD implantation should be based on a positive PVS, which is irreplaceable in risk stratification.

Optimization in cardiac resynchronization therapy with quadripolar leads offer improvement in cardiac energetics in heart failure patients compared with bipolar leads: HUMVEE Clinical Trial

Background

Cardiac resynchronization therapy (CRT) is a well-established technique for symptomatic heart failure (HF) patients, producing significant clinical benefits. Recent studies have revealed the potential role of multipoint pacing (MPP) in improving response and clinical outcomes. The aim of this work from the Heart failUre study of Multisite pacing effects on VEntriculoartErial coupling (HUMVEE) trial was to evaluate the association between MPP of the left ventricle vs those of optimized biventricular pacing (optBVP) on: a) ventriculoarterial coupling (VAC) and energy efficiency of the failing heart. Both BVP and MPP mode were optimized according to the optimal VTI value of left ventricular outflow track.

Methods

HUMVEE is a single-center, prospective (13 months) trial (clinicaltrials.gov identifier NCT03189368), of 80 NYHA III patients (68±10 years; 75% men; 53% ischemic cardiomyopathy), under optimal tolerated therapy, with standard BVP indication, having being implanted with a CRT system able to deliver both modes of pacing. Echocardiographic measurements, including VAC calculation, 6-min-walking-test and quality of life (MLHF questionnaire) were measured at baseline, 6 months post BVP optimization (right before MPP activation) and at the end of follow-up (6 months post MPP optimization). Cardiac power (CP) was calculated according the equation: CP=Cardiac Output x Mean Aortic Pressure/451.

Results

23 patients (30%), due to inability to deliver MPP, remained in optBVP. Those in MPP had 45% ischemic cardiomyopathy vs. 65% in optBVP patients, (p=0.056); ejection fraction 26.5%, vs. 29.5%, p=0.05; while there was no significant difference in gender, age and baseline NYHA class. Both optBVP and MPP patients improved VAC (baseline: 1,26±0,3; CRT: 1.18±0.4; MPP: 1.07±0.06, p=0.07); but only MPP patients significant improved from baseline to 12-months (p=0.02); CP was improved in both groups (p=0.02 in optBVD and p=0.01 in MPP), with MPP patients showing improvement in CP by 30% vs 12% in optBVP (p=0.001); 6-min-walk test was improved in MPP patients by 42% from baseline (p=0.0001), compared to optBVP patients who showed improvement up to 30% (p=0.05) and during the first 6 months only. NtproBNP levels were decreased in all patients (p=0.05 for MPP and p=0.07 for optBVP). Only patients who achieved MPP showed improvement in the Quality of life score (baseline: 31.6±23; optBVD:20.1±17; MPP:15.8±12, p=0.002; while those remained in optBVP showed no significant improvement.

Conclusions

MPP is a new, promising biventricular pacing modality offering additive effects on myocardial energy balance, cardiac power, systolic and diastolic ventricular function and aortoventricular coupling. HUMVEE trial illustrates those clinical, imaging and biochemical divergences of MPP from even opt BVP that confer significant improvement in quality of life reflecting better myocardial energy handling in patients with advanced HF and cardiac dysychronization.

Funding Acknowledgement

Type of funding source: None

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

The combined effect of Sacubitril-valsartan treatment on right ventricular function and cardiorespiratory response in patients with chronic heart failure

 

Cardiorespiratory response, right ventricular and global diastolic function is known to deteriorate the clinical course of patients with chronic heart failure with reduced ejection fraction (HFrEF), even under optimal treatment. In this work we sought to evaluate the impact of sacubitril/valsartan initiation in patients with chronic HFrEF in NYHA clinical status II-III, under optimal medical and invasive treatment. Methods 180 patients (85% male, mean age 62±9 years old, 60% ischemic heart failure, 73% with ICD, 45%with CRT and 45% with diabetes mellitus) in NYHA classification II-III-, who were prescribed Sacubitril-Valsartan were evaluated.

Clinical status, biochemical parameters, cardiorespiratory exercise response and bi-ventricular Doppler indices were evaluated at first visit and 6 months after. The pulsed tissue Doppler imaging of the systolic and diastolic function of mitral and tricuspid annulus was characterized by the systolic waves Smv and Stv, and the diastolic waves: Emv and Amv; E was the early filling wave in transmitral velocity. Left atrial maximal volume and global longitudinal strain of the left ventricle (GLPS) were measured. In cardiorespiratory exercise Vo2max, VE/VCO2 and Mets achieved were evaluated. All of them received b-blockers, 90% eplerenone or spironolactone, 25% ivabradine and 90% diuretic treatment. Seventy percent of them started with the dose of 50mg of sacubitril/valsartan; while 80% finally received the full dose of 200 mg bid. One third of them were on clinical status NYHA III.

Results

Eight of the patients discontinued the medication due to hypotension or renal function worsening. All patients expressed improvement in clinical status; while diuretic therapy was down titrated in all of them and discontinued in 30%. As compared with the initial examination, tricuspid annulus systolic wave velocity increased by 5% (p=0.04); maximum volume of left atrium was decreased by 6% (p=0.004); GLPS average was improved by 41% (p=0.001) and E/Emv ratio was decreased by 22% (p=0.04). Moreover, improvement in Stv was more prominent in DCM as compared to IHF patients; In cardio respiratory exercise VE/VCO2 decreased by 5% (p=0.05); while VO2 max showed a trend in improvement (p=0.06), with no difference detected between DCM and ICM patients; although there was a significant increase (47%) in METS achieved (p=0.02).

Conclusion

Sacubitril/valsartan initiation was associated with improved left diastolic function and right ventricular function, along with functional status improvement in patients with HFrEF. These finding underline the beneficial role of sacubitril/valsartan initiation on the hemodynamic course of patients with systolic heart failure and clinical status deterioration.

Funding Acknowledgement

Type of funding source: None

Combined lack of blood pressure and lipid control is a major risk factor for mortality in hypertensive patients: a single-center study

Background

Hypertension and dyslipidemia are well-known risk factors for cardiovascular disease (CVD). In such patients, lowering blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) and targeting to values below pre-specified cut-offs prevents CV events and improves prognosis. However, the impact of both BP and LDL-C control as compared to control of only one and/or none of these two risk factors is not well-studied.

Methods

Among 2,380 treated patients with hypertension and no overt CVD at baseline, we assessed the trajectory of BP control in 1,142 subjects with 4 or more follow up visits; BP control was defined as BP<140/90 mmHg in half or more visits. In the same subgroup, data on lipid control according to LDL-C goals were available in 1,032 patients in 2 or 3 visits. The HeartScore was used to estimate the risk of all-cause death at baseline.

Results

Across a median follow up of 108 months, 26 deaths (2.44%) were recorded. Despite appropriate anti-hypertensive treatment, 376 patients (32.92%) did not achieve conventional BP control in half or more of follow-up visits. Respectively, 59.83% of the study population did not meet the LDL-C goals in at least one assessment. Patients with suboptimal BP control had almost 3-fold increased risk for all-cause mortality (HR=2.85, 95% CI 1.31–6.21, P=0.008) as compared to subjects with effective control. This association was not attenuated after taking into account age, gender, body mass index, smoking, and diabetes mellitus (adjusted HR=2.54, 95% CI 1.13–5.72, P=0.025). Ineffective LDL-C control was not related to death (HR=1.31, 95% CI 0.688–2.48). However, patients who did not reach treatment goals for both BP and LDL showed substantially increased risk for all-cause mortality (HR=5.42, 95% CI 1.09–26.9, P=0.039). Importantly, suboptimal BP control in our cohort of hypertensive patients was associated with death independently of the HeartScore (adjusted HR=2.65, 95% CI 1.22–5.77, P=0.014) and conferred incremental reclassification value on top of the baseline risk (continuous NRI=0.467, P=0.016).

Conclusions

Suboptimal BP control was related to all-cause mortality in our cohort of hypertensive patients; importantly, this association was substantially stronger in concurrent presence of LDL-C values above treatment targets, thus, highlighting the need for combined achievement of BP and LDL-C control. Moreover, association of suboptimal BP controlwith death was independent of the HeartScore, suggesting that BP control should be considered in risk stratification of hypertensive patients

Funding Acknowledgement

Type of funding source: None

P4534The Mediterranean diet benefit in chronic heart failure by decoding central and peripheral vessel rheology, atheroma formation and serum prolactin levels

Background

Central hemodynamics and especially wave reflection amplification exhibit a vital parameter of chronic heart failure (CHF) physiology. Erectile dysfunction (ED) displays a poor peripheral vessel rheology and serum prolactin role is still debated in CHF mechanisms. The Mediterranean diet (Med-diet) is famous for its vasoprotective and wellbeing properties.

Purpose

To investigate the effect of the Med-diet in central hemodynamics, erectile status, atheroma formation and serum prolactin levels in male patients with chronic heart failure.

Methods

123 CHF male patients under optimal medical therapy enrolled the study (mean age: 65±8 yo, NYHA class II, ejection fraction <40%). All underwent evaluation of the carotid – femoral pulse wave velocity (PWV), estimation of central pressures and augmentation index (AIx) as parameter of wave reflection amplification (sphygmocor device). Ejection fraction (EF) of the left ventricle was estimated by using 2D echocardiography (Simpson method). ED severity and adherence to the Med-diet were assessed by the SHIM-5 (range: 0–25) and the Med-diet (range: 0–55) scores. Higher values point to better erectile function and a great Med-diet compliance respectively. Detection of atheroma was based on the intima- media thickness (IMT) of the common carotid artery. Prolactin levels were assessed in morning blood samples taken before 09:00 am.

Results

The SHIM −5 score (mean: 12±4) was associated to the AIx (p=0,03, r=0,75) and both positively and strongly related to the Med-diet score (p=0,01, r=0,8 and p=0,01, r=0,75 respectively). Med-diet compliance was negatively associated to IMT (p=0,02, r=−0,8) and serum prolactin levels (p=0,03, r=−0,6).Moreover, we notice a positive association between prolactin and the IMT (p=0,04, r=0,7). By multiple linear regression analysis the relation of SHIM-5 and Med-diet score remained significant (p=0,04) after adjustment for BMI, central pulse and mean arterial pressures. We further subdivide our population according to the mean Med-diet value (28) into high and low Med-diet adherence groups. Only in the group with the greater Med-diet adherence (n=73, 60%) AIx was strongly associated to the SHIM-5 score (p=0,02) even after adjustment for PWV, age and BMI. Prolactin levels there were still related to IMT (p=0,04) after adjustment for PWV, AIx, BMI and central pulse pressure. All statistics remained significant when adjusting for ejection fraction of the left ventricle.

Conclusion

High adherence to the Med-diet benefits CHF hemodynamics by enforcing wave reflection amplification, thus generating a stronger pulse signal to peripheral vasculature. Moreover suppresses serum prolactin levels that relates to atheroma formation. Both actions enhance erectile performance independently of the EF of the left ventricle. It is important to advise CHF patients to adopt this dietary pattern in order to improve hemodynamic status and the sense of wellbeing.

P4529Atrioventricular optimization in cardiac resynchronization therapy with quadripolarleads, improves energy handling and quality of life in heart failure patients: HUMVEE Trial

Background

Cardiac resynchronization therapy (CRT) is a well-established technique for symptomatic heart failure (HF) patients, producing significant clinical benefits. Recent studies have revealed the potential role of multipoint pacing (MPP) in improving response and clinical outcomes. The aim of Heart failUre study of Multisite pacing effects on VEntriculoartErial coupling (HUMVEE) trial was to evaluate the association between MPP of the left ventricle vs those of standard biventricular pacing (BVP) on: a) ventriculoarterial coupling (VAC) and energy efficiency of the failing heart, b) diastolic function, c) quality of life, and d) NT-proBNP levels.

Methods

HUMVEE is a single-center, prospective (13 months) trial (clinicaltrials.gov identifier NCT03189368), of 54 NYHA III patients (69±9 years; 79% men; 50% dilated cardiomyopathy), under optimal tolerated medical therapy, with standard BVP indication, having being implanted with a CRT system able to deliver both modes of pacing. Creatinine and NT-proBNP levels and echocardiographic measurements (VAC calculation, strain rate, diastolic function assessment), as well as 6-min-walking-test and quality of life (MLHF questionnaire) were measured at baseline, 6 months post BVP optimization (right before MPP activation) and at the end of follow-up (6 months post MPP optimization). Cardiac power (CP) was calculated according the equation: CP=Cardiac Output x Mean Aortic Pressure/451.

Results

Both CRT and MPP improved 6-min-walk (differences at baseline/6 mo/end of FU: 277±27 vs. 345±27 vs 363±27 m, p=0.07); left ventricular ejection fraction (24,2% vs 30,6%vs, 32%, p=0.05); end -diastolic diameters of left ventricle (65±1,4 vs. 63±1.7 vs. 61±1.1, p=0.03); end-systolic volume (150±15 vs. 140±10 vs. 131±13, p=0.08); stroke volume (41.6±9 vs. 53.6±14 vs. 62±9, p=0.0001 for MPP); left atrial volume (76±5 vs. 74±10 vs 61±6, p=0.001 for MPP), E/Emv (14±5 vs. 12±4 vs. 11±3, p=0.05 for MPP); NtproBNP (2782±1000 vs. 2080±2500 vs. 2000±1000, p=0.05 for MPP). VAC was reduced from 1.14±0.27 to 1.1±0.17 (p=0.1) while CP increased from 564.2±142 to 768±103 (p=0.009). Quality of life score (the lower the better) improved from 23.75±17 at baseline to 17.25±10 at end of FU (p=0.05).

Conclusions

MPP is a new, promising pacing modality with the potential to improve HF patients' outcome, offering additive effects on myocardial energy balance, cardiac power, systolic and diastolic ventricular function and aortoventricular coupling, especially in ischemic patients. HUMVEE trial illustrates those clinical, imaging and biochemical divergences of MPP from standard BVP that reflect significant improvement in quality of life in patients with advanced HF and cardiac dysychronization.

Skeletal muscle mass in acute coronary syndrome prognosis: Gender-based analysis from Hellenic Heart Failure cohort

BACKGROUND AND AIMS

Predictive and prognostic ability of muscle mass in CVD settings is increasingly discussed. The gender-specific effect of skeletal muscle mass index (SMI) on 10-year recurrent fatal/non fatal cardiovascular disease (CVD) event of acute coronary syndrome (ACS) patients was evaluated.

METHODS AND RESULTS

In 2006-2009, n = 1000 consecutive patients (n = 222 women), hospitalized at the First Cardiology Clinic of Athens with ACS diagnosis and with symptoms and left ventricular function indicative of heart failure were selected. SMI was created to reflect skeletal muscle mass through appendicular skeletal muscle mass (indirectly calculated through population formulas) divided by body mass index (BMI). In the 10-year follow-up (2016), 55% of ACS patients experienced recurrent fatal/non fatal CVD events (53% in women vs.62% in men, p = 0.04). Patients in the 2nd SMI tertile (mostly overweight) had 10% lower risk for CVD recurrence (women:men rate ratio = 0.87) over their counterparts in the 1st (mostly normalweight) and 3rd tertile (mostly obese). Multivariate analysis revealed that ACS patients in the 2nd SMI tertile presented 46% and 85% lower CVD event risk over their counterparts in the 1st tertile (Hazard Ratio (HR) = 0.54, 95% Confidence Interval (95% CI) 0.30, 0.96, p = 0.002) and 3rd tertile (HR = 1.85, 95%CI 1.05, 2.94, p = 0.03). Gender-based analysis revealed that this trend remained significant only in women. Inflammatory markers had strong confounding effect.

CONCLUSION

A U-shape association between SMI and 10-year CVD event especially in women was highlighted. This work reveals gender-specific remarks for "obesity-lean paradox" in secondary prevention, implying that high muscle mass accompanied by obesity and excess adiposity may not guarantee better prognosis.

Multiple syncope mechanisms coexisting in a Brugada syndrome patient requiring a single therapeutic approach

We report the case of a Brugada syndrome patient with a history of syncopal and presyncopal episodes and evidence of sinus node and atrioventricular (AV) conduction abnormalities. The patient developed sinus bradycardia, sinoatrial conduction abnormalities, prolonged HV interval, early appearance of AV block, AV nodal reentrant tachycardia and polymorphic ventricular tachycardia in the electrophysiological study. He was treated with a dual-chamber pacemaker defibrillator. At the 9-year follow-up, the patient remained asymptomatic with several episodes of 1:1 AV-relationship tachycardia, interrupted with antitachycardia pacing, while the predominant pacing states of the device were AP-VS and AS-VP for most of the time.

Changes of the T-wave amplitude and angle: an early marker of altered ventricular repolarization in hypertension

BACKGROUND

The heterogeneity of ventricular repolarization is an important proarrhythmic factor. QT dispersion has been proposed to reflect the inhomogeneity of ventricular repolarization, but a poor reproducibility limits its clinical applicability. Reliable noninvasive methods to quantify abnormalities in ventricular repolarization are still lacking. The T-loop morphology analysis is a novel method aimed at quantifying ventricular repolarization.

HYPOTHESIS

To test the ability of the T-loop morphology analysis to discriminate between hypertensive patients and healthy subjects, 105 hypertensive patients (mean age 63.6 +/- 12.3 years) and 110 healthy controls (mean age 49.7 +/- 14.3 years) were evaluated.

METHODS

The maximum QT interval (QT maximum), the minimum QT interval (QT minimum), and their difference (QT dispersion) were calculated from a digitally recorded 12-lead electrocardiogram (ECG) in both study groups. X, Y, and Z leads were reconstructed from the 12-lead ECG, and the amplitude of the maximum T vector (T amplitude) and the angle between the maximum T vector and X axis (T angle) were calculated from the projection of the T loop in the frontal plane.

RESULTS

T amplitude (p < 0.001), T angle (p = 0.05), and QT dispersion (p = 0.04) were significantly different between hypertensive patients and controls, while QT maximum (p = 0.14) and QT minimum (p = 0.35) did not differ between the groups. T amplitude was the only marker which differed between hypertensive patients without ECG criteria for left ventricular hypertrophy and controls (p = 0.002).

CONCLUSIONS

T-loop features and particularly T amplitude are significantly different between hypertensive patients and healthy controls and may serve as early markers of repolarization abnormalities in a hypertensive population.

Spatial QRS-T angle: association with diabetes and left ventricular performance

The spatial QRS-T angle obtained by vectorcardiography is a combined measurement of the electrical activity of the heart and predicts cardiovascular morbidity and mortality. Disturbances in repolarization and depolarization are common in diabetes. No data, however, exist on the effect of diabetes on QRS-T angle. In this study we examined differences in QRS-T angle between type 2 diabetic and non-diabetic subjects; in addition, the potential relationship between QRS-T angle and left ventricular performance as well as glycaemic control were also examined. A total of 74 subjects with type 2 diabetes and 74 non-diabetic individuals, matched for age and sex with the diabetic subjects were examined. All subjects were free of clinically apparent macrovascular complications. Spatial vectorcardiogaphic descriptors of ventricular depolarization and repolarization were reconstructed from the 12-electrocardiographic leads using a computer-based electrocardiogram. Left ventricular mass and performance were measured using M-mode and Doppler echocardiography. QRS-T angle values were higher (by almost 2-fold) in the diabetic in comparison with the non-diabetic subjects (P < 0.001). After multivariate adjustment, QRS-T angle was independently associated with age (P = 0.01), HbA(1c) (P = 0.003), and low-density lipoprotein cholesterol levels (P = 0.04) in the non-diabetic, and with HbA(1c) (P = 0.03) as well as Tei index (P = 0.003) in the diabetic subjects. The spatial QRS-T angle is high in subjects with type 2 diabetes and is associated with glycaemic control and left ventricular performance. The prognostic importance of the higher spQRS-T angle values in subjects with diabetes remains to be evaluated in prospective studies.

CLimate Impacts on Myocardial infarction deaths in the Athens TErritory: the CLIMATE study

OBJECTIVE

To evaluate the impact of meteorological variables on daily and monthly deaths caused by acute myocardial infarction (AMI).

METHODS

All death certificate data from the Athens territory were analysed for AMI deaths in 2001. Daily atmospheric temperature, pressure and relative humidity data were obtained from the National Meteorological Society for Athens for the same year.

RESULTS

The total annual number of deaths caused by AMI was 3126 (1953 men) from a population of 2,664,776 (0.117%). Seasonal variation in deaths was significant, with the average daily AMI deaths in winter being 31.8% higher than in summer (9.89 v 7.35, p < 0.001). Monthly variation was more pronounced for older people (mean daily AMI deaths of people older than 70 years was 3.53 in June and 7.03 in December; p < 0.001) and of only marginal significance for younger people. The best predictor of daily AMI deaths was the average temperature of the previous seven days; the relation between daily AMI deaths and seven-day average temperature (R(2) = 0.109, p < 0.001) was U-shaped. Considering monthly AMI death rates, only mean monthly humidity was independently associated with total deaths from AMI (R(2) = 0.541, p = 0.004).

CONCLUSION

Ambient temperature is an important predictor of AMI mortality even in the mild climate of a Mediterranean city like Athens, its effects being predominantly evident in the elderly. Mean monthly humidity is another meteorological factor that appears to affect monthly numbers of AMI deaths. These findings may be useful for healthcare and civil protection planning.

The effects of cigarette smoking on the heterogeneity of ventricular repolarization

BACKGROUND

Although the circulatory effects of cigarette smoking have been studied extensively, its impact on ventricular repolarization has not been adequately evaluated.

METHODS

The goal of our study was to determine whether cigarette smoking influences the spatial and temporal heterogeneity of ventricular repolarization in a population of young, healthy, male subjects. A digital 12-lead surface electrocardiogram was obtained from 1394 men recruited from the Hellenic Air Force and classified as smokers and nonsmokers. The maximum, minimum, and median QT intervals, QT dispersion (QT maximum - QT minimum), the rate-corrected maximum and median QT intervals, the slopes of the QT maximum/RR and QT median/RR regression equations, and the vectorcardiographic markers spatial T amplitude and spatial QRS-T angle were evaluated in the 2 groups.

RESULTS

Heart rate was significantly higher (P <.001) in smokers (n =691) compared with nonsmokers (n = 703). QT maximum, QT minimum, and QT median were significantly lower (P <.001), whereas the rate-corrected QT maximum (P =.04) and QT median (P =.06) were marginally higher in smokers than in nonsmokers. The spatial T amplitude was lower (P =.002), whereas the spatial QRS-T angle was higher (P =.01) in smokers compared with nonsmokers. Neither QT dispersion nor the slopes of the QT/RR and the spatial descriptors/RR regression equations differed between smokers and nonsmokers.

CONCLUSIONS

Ventricular repolarization is altered in young male cigarette smokers. The differences in the heterogeneity of ventricular repolarization between smokers and nonsmokers are mainly due to heart rate differences between the 2 study groups.

Spatial aspects of ventricular repolarization in postinfarction patients

QT dispersion has been proposed to reflect the heterogeneity of ventricular repolarization, but a poor reproducibility limits its clinical usefulness. Spatial vectorcardiographic descriptors constitute a novel approach to quantify ventricular repolarization. To test the ability of vectorcardiographic descriptors to discriminate among different subsets of postinfarction patients, 50 consecutively recruited patients with acute MI, 50 patients with history of an old (> 6 months) MI, and 50 healthy controls were evaluated. The maximum and minimum QT and JT intervals and QT and JT dispersion were manually measured from a digitally recorded 12-lead ECG. X, Y, and Z leads were reconstructed from the 12-lead ECG. The amplitude of the maximum spatial T vector (spatial T amplitude), the angle between the maximum spatial QRS and T vectors (spatial QRS-T angle), and the frontal plane QRS-T angle were automatically calculated. The spatial T amplitude and the spatial QRS-T angle did not differ between patients with a recent and those with an old MI (P = 1). QT dispersion was significantly lower in patients with an old MI than in patients with a recent one (P = 0.002). The spatial repolarization descriptors showed better short-term reproducibility than the dispersion indices. In conclusion, the spatial T amplitude and the spatial QRS-T angle are accurate measures of ventricular repolarization that do not differ between patients with recent and those with old MI. The different QT dispersion values observed in this study between the two post-MI groups should be considered cautiously because of the low accuracy of the manual measurements.

The spatial QRS-T angle as a marker of ventricular repolarisation in hypertension

Ventricular repolarisation abnormalities are important in arrhythmia provocation. The dispersion of repolarisation duration is not the only aspect of repolarisation heterogeneity. Spatial vectorcardiographic descriptors constitute a novel approach to quantify ventricular repolarisation. To test the ability of vectorcardiographic descriptors to discriminate between hypertensives with high or low blood pressure (BP), 110 treated hypertensives (mean age 63.6 +/- 12.1 years) were classified in the high (systolic BP > or = 160 mm Hg or diastolic BP > or = 95 mm Hg) (n = 67), or the low (systolic BP < 160 mm Hg and diastolic BP <95 mm Hg) (n = 43) BP group. The maximum QT, JT, and T peak-T end intervals and the QT, JT, and T peak--T end dispersion were calculated from a digitally recorded 12-lead electrocardiogram (ECG). X, Y, and Z leads were reconstructed from the 12-lead ECG. The amplitude of the maximum spatial T vector (spatial T amplitude), the angle between the maximum spatial QRS and T vectors (spatial QRS-T angle) and the frontal plane QRS-T angle were calculated. The spatial QRS-T angle was higher in patients with high compared to those with low BP (P = 0.025). All conventional ECG markers of the dispersion of ventricular repolarisation duration failed to demonstrate significant differences between hypertensives with high or low BP. In conclusion, the spatial QRS-T angle was significantly increased in those treated hypertensive patients who showed repeatedly high BP values. Hence, we may suggest that the angle between the directions of ventricular depolarisation and repolarisation is a sensitive marker of the repolarisation alterations in systemic hypertension. Journal of Human Hypertension (2001) 15, 63-70

New descriptors of homogeneity of the propagation of ventricular repolarization

Available descriptors of irregularities of ventricular repolarization are of limited clinical value. We studied the effect of autonomic variations on several new descriptors of the three-dimensional T loop. Twelve-lead digital ECGs were recorded continuously in 40 healthy subjects at baseline in the supine position, during postural changes (supine-->sitting-->standing-->supine-->standing), and during Valsalva maneuver performed three times in the supine and three times in the standing positions. A minimum dimensional space was constructed from the 12-lead ECG, using singular value decomposition, on the basis of median ECG beats constructed from 10-second consecutive ECG recordings. Temporal variations (TLA and PL, which measure the T loop area, and LD, the interlead relationship during repolarization) and wavefront direction descriptors (TCRT, the deviation between the QRS and T vectors) were calculated and expressed as normalized values. Values of TLA, PL, and TCRT were significantly lower in the sitting than in the supine position (-38,139 +/- 9099 vs 47,133 +/- 7511, -0.017 +/- 0.005 vs 0.033 +/- 0.005 and -0.032 +/- 0.019 vs 0.071 +/- 0.015, respectively, P < 0.001 for all) and decreased further in the standing position (-88,288 +/- 14,468, -0.067 +/- 0.013, -0.198 +/- 0.025, respectively, P < 0.001 for all). LD increased from supine to sitting (98.7 +/- 29.4 vs -87.5 +/- 15.2, P < 0.001) and increased further, though nonsignificantly in the standing position (118.3 +/- 35.2). TLA, PL, and TCRT decreased from baseline during Valsalva in the supine (-34,118 +/- 11,424 vs 62,234 +/- 12,215, -0.038 +/- 0.014 vs 0.065 +/- 0.010, -0.08 +/- 0.03 vs 0.10 +/- 0.02, respectively, P < 0.001 for all) and standing positions (-108,263 +/- 21,051 vs -68,909 +/- 10,271, -0.109 +/- 0.014 vs -0.048 +/- 0.009, -0.30 +/- 0.035 vs -015 +/- 0.016, respectively, P < 0.05 for all). LD was significantly increased by Valsalva in the supine position (13 +/- 46 vs -153 +/- 30, P < 0.001) and nonsignificantly in the standing position (99 +/- 50 vs 86 +/- 30, P = NS). There were significant correlations among TLA, PL, and LD, and no significant correlation between TCRT and any of the temporal variation descriptors. These new temporal and wavefront direction descriptors are sensitive and rapid detectors of autonomic effects on ventricular repolarization.

Reflex autonomic modulation of automatically measured repolarization parameters

Automatic recognition of repolarization abnormalities from the standard electrocardiogram (ECG) is of considerable clinical importance. This study examined the autonomic variations in automatically measured repolarization parameters, including maximum QT interval (QTmax), global QT dispersion (QTd), T area dispersion (T area D) and principal component analysis ratio 2 (PCA-2). Twelve-lead ECGs were recorded continuously in 40 healthy subjects during supine, sitting and standing positions, and during the Valsalva maneuver. With the exception of PCA-2, the other repolarization parameters correlated either moderately or strongly during the steady-state supine position. QTmax, PCA-2, and T area D decreased significantly between supine and sitting position (P < 0.001, P < 0.001 and P < 0.01, respectively). QTmax, QTD, and T area D decreased significantly between sitting and standing (P < 0.001, P < 0.05 and P < 0.01, respectively). All parameters significantly decreased between supine and standing position: QTmax (P < 0.001), QTD (P < 0.05), PCA-2 (P < 0.05) and T area D (P < 0.001). During Valsalva, only PCA-2 increased significantly (P < 0.001) between supine and standing position. There were no significant changes in QT dispersion and dispersion of T wave area during Valsalva, compared to baseline, in both supine and standing positions. Automatic conventional measures of repolarization heterogeneity have limited practical value in detecting the effects of autonomic changes on ventricular repolarization. Newer concepts evaluating spatial and temporal irregularity of ventricular repolarization are still needed to reliably detect the effects of autonomic activity on ventricular repolarization.

Comparison of different methods for manual P wave duration measurement in 12-lead electrocardiograms

To determine whether different methods for the manual measurement of P wave duration are mutually consistent, we evaluated the intraobserver and interobserver errors of P wave measurements obtained in three different ways: (1) by cursor on a high resolution computer screen (on screen), (2) by calipers and a magnifying glass (on paper), and (3) by a high resolution digitizing board (on board). The agreement between the methods was assessed in 30 normal subjects and 30 patients with a history of atrial fibrillation. The maximum P wave duration (P maximum), the minimum P wave duration (P minimum), mean P wave duration (P mean), P wave dispersion (P dispersion = P maximum - P minimum), and the standard deviation of the P wave duration in all measured leads (P SD) were calculated from a 12-lead electrocardiogram in each subject. Only P maximum, P mean, and P dispersion were significantly higher in patients than in controls with all three methods. Intraobserver and interobserver relative errors were significantly different among the three methods; the lowest errors were associated with the on-screen measurement. The agreement between the three different methods was acceptable for P maximum, P mean, and P SD and rather poor for P minimum and P dispersion in both groups. The differences of the measurement by different methods did not consistently differ between the two groups. Hence, the on-screen measurements are consistent with other manual methods and provide more stable results. Manual measurement of ECG patterns should be preferably performed with digital ECG recordings displayed on a high resolution computer screen.