Interventricular Septal Thickness on Cardiac CT as a Novel Risk Factor for Conduction Disturbances in Patients Undergoing Transcatheter Aortic Valve Replacement

OBJECTIVE

We examined whether thickness of the basal muscular interventricular septum (IVS), as measured by pre-procedural computed tomography (CT), could be used to identify the risk of conduction disturbances following transcatheter aortic valve replacement (TAVR).

BACKGROUND

The IVS is a pivotal region of the electrical conduction system of the heart where the atrioventricular conduction axis is located.

METHODS

Included were 78 patients with severe aortic stenosis who underwent CT imaging prior to TAVR. The thickness of muscular IVS was measured in the coronal view, in systolic phases, at 1, 2, 5, and 10 mm below the membranous septum (MS). The primary endpoint was a composite of conduction disturbance following TAVR.

RESULTS

Conduction disturbances occurred in 24 out of 78 patients (30.8%). Those with conduction disturbances were significantly more likely to have a thinner IVS than those without conduction disturbances at every measured IVS level (2.98 ± 0.52 mm vs. 3.38 ± 0.52 mm, 4.10 ± 1.02 mm vs. 4.65 ± 0.78 mm, 6.11 ± 1.12 mm vs. 6.88 ± 1.03 mm, and 9.72 ± 1.95 mm vs. 10.70 ± 1.55 mm for 1, 2, 5 and 10 mm below MS respectively, p < 0.05 for all). Multivariable logistic regression analysis showed that pre-procedural IVS thickness (<4 mm at 2 mm below the MS) was a significant independent predictor of post-procedural conduction disturbance (adjOR 7.387, 95% CI: 2.003-27.244, p = 0.003).

CONCLUSION

Pre-procedural CT assessment of basal IVS thickness is a novel predictive marker for the risk of conduction disturbances following TAVR. The IVS thickness potentially acts as an anatomical barrier protecting the underlying conduction system from mechanical compression during TAVR.

Predictive value of the PRAETORIAN score for defibrillation test success in patients with subcutaneous ICD: A subanalysis of the PRAETORIAN-DFT trial

BACKGROUND

The PRAETORIAN score estimates the risk of failure of subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy by using generator and lead positioning on bidirectional chest radiographs. The PRospective randomized compArative trial of subcutanEous implanTable cardiOverter-defibrillatoR ImplANtation with and without DeFibrillation Testing (PRAETORIAN-DFT) investigates whether PRAETORIAN score calculation is noninferior to defibrillation testing (DFT) with regard to first shock efficacy in spontaneous events.

OBJECTIVE

This prespecified subanalysis assessed the predictive value of the PRAETORIAN score for defibrillation success in induced ventricular arrhythmias.

METHODS

This multicenter investigator-initiated trial randomized 965 patients between DFT and PRAETORIAN score calculation after de novo S-ICD implantation. Successful DFT was defined as conversion of induced ventricular arrhythmia in <5 seconds from shock delivery within 2 attempts. Bidirectional chest radiographs were obtained after implantation. The predictive value of the PRAETORIAN score for DFT success was calculated for patients in the DFT arm.

RESULTS

In total, 482 patients were randomized to undergo DFT. Of these patients, 457 (95%) underwent DFT according to protocol, of whom 445 (97%) had successful DFT and 12 (3%) had failed DFT. A PRAETORIAN score of ≥90 had a positive predictive value of 25% for failed DFT, and a PRAETORIAN score of <90 had a negative predictive value of 99% for successful DFT. A PRAETORIAN score of ≥90 was the strongest independent predictor for failed DFT (odds ratio 33.77; confidence interval 6.13-279.95; P < .001).

CONCLUSION

A PRAETORIAN score of <90 serves as a reliable indicator for DFT success in patients with S-ICD, and a PRAETORIAN score of ≥90 is a strong predictor for DFT failure.

Implantable Cardioverter Defibrillator for the Primary Prevention of Sudden Cardiac Death among Patients With Cancer

Data are limited regarding the characteristics and outcomes of patients with cancer who are found eligible for primary defibrillator therapy. We performed a single-center retrospective analysis of patients with preexisting cancer diagnoses who become eligible for a primary prevention implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT) defibrillator. Multicenter Automatic Defibrillator Implantation Trial-ICD (MADIT-ICD) benefit scores were calculated. The study included 75 cancer patients at a median age of 73 (interquartile range 64, 81) years at heart failure diagnosis. Active cancer was present in 51%. Overall, 55% of the cohort had coronary artery disease and 37% were CRT eligible. We found that 48%, 49%, and 3% of cohorts had low, intermediate, and high MADIT-ICD Benefit scores, respectively. Only 27% of patients underwent primary defibrillator implantation. Using multivariate analysis, indication for CRT and intermediate/high MADIT-ICD Benefit categories were found as independent predictors for implantation (odds ratio 8.42 p <0.001 and odds ratio 3.74 p = 0.040, respectively). During a median follow-up of 5.3 (interquartile range 4.5, 7.2) years, one patient (5%) with a defibrillator had appropriate shock therapy and 2 patients (10%) had bacteremia. Of 13 patients with CRT defibrillator-implants, one patient was admitted for heart failure exacerbation (8%). Using a time-varying covariate model, we did not observe statistically significant differences in the survival of patients with cancer implanted versus those not implanted with primary defibrillators (hazard ratio 0.521, p = 0.127). In conclusion, although primary defibrillator therapy is underutilized in patients with cancer, its relative benefit is limited because of competing risk of nonarrhythmic mortality. These findings highlight the need for personalized cardiologic and oncologic coevaluation.

Consumer-Led Screening for Atrial Fibrillation: Frontier Review of the AF-SCREEN International Collaboration

The technological evolution and widespread availability of wearables and handheld ECG devices capable of screening for atrial fibrillation (AF), and their promotion directly to consumers, has focused attention of health care professionals and patient organizations on consumer-led AF screening. In this Frontiers review, members of the AF-SCREEN International Collaboration provide a critical appraisal of this rapidly evolving field to increase awareness of the complexities and uncertainties surrounding consumer-led AF screening. Although there are numerous commercially available devices directly marketed to consumers for AF monitoring and identification of unrecognized AF, health care professional-led randomized controlled studies using multiple ECG recordings or continuous ECG monitoring to detect AF have failed to demonstrate a significant reduction in stroke. Although it remains uncertain if consumer-led AF screening reduces stroke, it could increase early diagnosis of AF and facilitate an integrated approach, including appropriate anticoagulation, rate or rhythm management, and risk factor modification to reduce complications. Companies marketing AF screening devices should report the accuracy and performance of their products in high- and low-risk populations and avoid claims about clinical outcomes unless improvement is demonstrated in randomized clinical trials. Generally, the diagnostic yield of AF screening increases with the number, duration, and temporal dispersion of screening sessions, but the prognostic importance may be less than for AF detected by single-time point screening, which is largely permanent, persistent, or high-burden paroxysmal AF. Consumer-initiated ECG recordings suggesting possible AF always require confirmation by a health care professional experienced in ECG reading, whereas suspicion of AF on the basis of photoplethysmography must be confirmed with an ECG. Consumer-led AF screening is unlikely to be cost-effective for stroke prevention in the predominantly young, early adopters of this technology. Studies in older people at higher stroke risk are required to demonstrate both effectiveness and cost-effectiveness. The direct interaction between companies and consumers creates new regulatory gaps in relation to data privacy and the registration of consumer apps and devices. Although several barriers for optimal use of consumer-led screening exist, results of large, ongoing trials, powered to detect clinical outcomes, are required before health care professionals should support widespread adoption of consumer-led AF screening.

Automated detection of atrial fibrillation based on vocal features analysis

INTRODUCTION

Early detection of atrial fibrillation (AF) is desirable but challenging due to the often-asymptomatic nature of AF. Known screening methods are limited and most of them depend of electrocardiography or other techniques with direct contact with the skin. Analysis of voice signals from natural speech has been reported for several applications in medicine. The study goal was to evaluate the usefulness of vocal features analysis for the detection of AF.

METHODS

This prospective study was performed in two medical centers. Patients with persistent AF admitted for cardioversion were enrolled. The patients pronounced the vowels "Ahh" and "Ohh" were recorded synchronously with an ECG tracing. An algorithm was developed to provide an "AF indicator" for detection of AF from the speech signal.

RESULTS

A total of 158 patients were recruited. The final analysis of "Ahh" and "Ohh" syllables was performed on 143 and 142 patients, respectively. The mean age was 71.4 ± 9.3 and 43% of patients were females. The developed AF indicator was reliable. Its numerical value decreased significantly in sinus rhythm (SR) after the cardioversion ("Ahh": from 13.98 ± 3.10 to 7.49 ± 1.58; "Ohh": from 11.39 ± 2.99 to 2.99 ± 1.61). The values at SR were significantly more homogenous compared to AF as indicated by a lower standard deviation. The area under the receiver operating characteristic curve was >0.98 and >0.89 ("Ahh" and "Ohh," respectively, p < .001). The AF indicator sensitivity is 95% with 82% specificity.

CONCLUSION

This study is the first report to demonstrate feasibility and reliability of the identification of AF episodes using voice analysis with acceptable accuracy, within the identified limitations of our study methods. The developed AF indicator has higher accuracy using the "Ahh" syllable versus "Ohh."

Impact of lockdown during COVID-19 pandemic on physical activity and arrhythmia burden in heart failure patients

BACKGROUND

Restricted outdoor activity during COVID-19 related lockdown may accelerate heart failure (HF) progression and thereby increase cardiac arrhythmias. We analyzed the impact of March/April 2020 lockdown on physical activity and arrhythmia burden in HF patients treated with cardiac resynchronization therapy (CRT) devices with daily, automatic remote monitoring (RM) function.

METHODS

The study cohort included 405 HF patients enrolled in Observation of Clinical Routine Care for Heart Failure Patients Implanted with BIOTRONIK CRT Devices (BIO|STREAM.HF) registry in 16 countries, who had left ventricular ejection fraction (LVEF) ≤40% (mean 28.2 ± 6.6%) and NYHA class II/III/IV (47.9%/49.6%/2.5%) before CRT pacemaker/defibrillator implantation. The analyzed RM data comprised physical activity detected by accelerometer, mean heart rate and nocturnal rate, PP variability, percentage of biventricular pacing, atrial high rate episode (AHRE) burden, ventricular extrasystoles and tachyarrhythmias, defibrillator shocks, and number of implant interrogations (i.e., follow-ups). Intraindividual differences in RM parameters before (4-week period) versus during (4-week period) lockdown were tested for statistical significance and independent predictors were identified.

RESULTS

There was a significant relative change in activity (mean -6.5%, p < .001), AHRE burden (+17%, p = .013), and follow-up rate (-75%, p < .001) during lockdown, with no significant changes in other RM parameters. Activity decreased by ≥8 min/day in 46.5% of patients; predictors were higher LVEF, lower NYHA class, no defibrillator indication, and more activity before lockdown. AHRE burden increased by ≥17 min/day in 4.7% of patients; predictors were history of atrial fibrillation, higher LVEF, higher body mass index, and activity decrease during lockdown.

CONCLUSION

Unfavorable changes in physical activity, AHRE burden, and follow-up rate were observed during lockdown, but not in ventricular arrhythmia.

Radial strain imaging-guided lead placement for improving response to cardiac resynchronization therapy in patients with ischaemic cardiomyopathy: the raise cardiac resynchronization therapy trial

AIMS

To evaluate the benefit of speckle tracking radial strain imaging (STRSI)-guided left ventricular (LV) lead (LVL) positioning in cardiac resynchronization therapy (CRT) in patients (pts) with ischaemic cardiomyopathy with CRT indication.

METHODS AND RESULTS

We conducted a prospective randomized controlled trial. Patients were enrolled in nine centres with 2:1 randomization into two groups (guided vs. control). Patients underwent STRSI to identify the optimal LV position from six LV segments at midventricular level. Implantation via STRSI was attempted for recommended segment in the guided group only. Follow-up included echocardiography (6 months) and clinical evaluation (6 and 12 months). The primary endpoint was comparison % reduction in LV end-systolic volume at 6 months with baseline. Secondary endpoints included hospitalizations for heart failure and death, and improvement in additional echocardiographic measurements and quality of life score. A total of 172 patients (115 guided vs. 57 control) were enrolled. In the guided group, 60% of the implanted LV leads were adjudicated to be successfully located at the recommended segment, whereas in the control group 44% reached the best STRSI determined segment. There was no difference between the groups in any of the primary or secondary endpoints at 6 and 12 months.

CONCLUSION

Our findings suggest that echo-guided implantation of an LV lead using STRSI does not improve the clinical or echocardiographic response compared with conventional implantation.

Comparison of permanent pacemaker implantation rate after first and second generation of transcatheter aortic valve implantation-A retrospective cohort study

OBJECTIVES

This study aimed to compare permanent pacemaker implantation (PPMI) rates among patients undergoing Trans-catheter Aortic Valve Implantation (TAVI) with first generation (G1) versus second generation (G2) valves and the impact of PPMI on long-term mortality.

BACKGROUND

PPMI is a known adverse event after TAVI. Recently, two novel iterations of valve designs of both the balloon expandable valves (BEV) and self-expanding valves (SEV) were introduced as a second generation valves.

METHODS

All patients included in the Israeli multicenter TAVI registry were grouped according to valve type (BEV vs. SEV) and generation (G1 vs. G2). A comparison was made for clinical and outcome indices of patients undergoing TAVI with G1 and G2 in each of the valve systems.

RESULTS

A total of 1377 patients were included. The incidence of PPMI did not differ between G1-BEV versus G2-BEV (15.3% vs. 17.4%; p = 0.598) nor between G1-SEV versus G2-SEV (23.4% vs. 20.3%; p = 0.302). Depth of implantation and complete right bundle branch block were independently associated with PPMI post-TAVI in both valve systems. PPMI was not associated with an increased risk for 2-year mortality.

CONCLUSIONS

The incidence of PPMI remains a relevant adverse event post-TAVI even when the newer generation valves are used. Since the predictors for PPMI are well established, a standardized approach for the management of conduction disorders is much needed.

Safety of High-Dose Dabigatran in Elderly and Younger Patients with a Low Bleeding Risk: A Prospective Observational Study

INTRODUCTION

In patients with atrial fibrillation (AF) at risk for stroke, dabigatran 150 mg twice a day (DE150) is superior to warfarin for stroke prevention. However, there is paucity of data with respect to bleeding risk at this dose in elderly patients (≥75 years). We aimed to evaluate the safety of DE150 in comparison to warfarin in a real-world population with AF and low bleeding risk (HAS-BLED score ≤2).

METHODS

In this prospective observational study, 754 consecutive patients with AF and HAS-BLED score ≤2 were included. We compared outcome of elderly patients (age ≥75 tears) to younger patients (age <75 years). The primary end point was the combined incidence of all-cause mortality, stroke, systemic emboli, and major bleeding event during a mean follow-up of 1 year.

RESULTS

There were 230 (30%) elderly patients, 151 patients were treated with warfarin, and 79 were treated with DE150. Fifty-two patients experienced the primary endpoint during the 1-year follow-up. Among the elderly, at 1-year of follow-up, the cumulative event rate of the combined endpoint in the DE150 and warfarin was 8.9 and 15.9% respectively (p = 0.14). After adjustment for age and gender, patients who were treated with DE150 had a nonsignificant difference in the risk for the combined end point as patients treated with warfarin both among the elderly and among the younger population (HR 0.58, 95% C.I = 0.25-1.39 and HR = 1.12, 95% C.I 0.62-2.00, respectively [p for age-group-by-treatment interaction = 0.83).

CONCLUSIONS

Our results suggest that Dabigatran 150 mg twice a day can be safely used among elderly AF patients with low bleeding risk.

Impact of the Covid-19 related lockdown on physical activity, heart rate and arrhythmia burden in a large prospective cohort of CHF patients

Funding Acknowledgements

Type of funding sources: Private company. Main funding source(s): BIOTRONIK SE & Co. KG

OnBehalf

BIO|STREAM.HF

Background

At the beginning of the Covid-19 pandemic in spring 2020, governments around the world issued curfews and other stay at home orders (‘lockdown’) to limit the spread of the SARS-CoV19 virus. This may have forced people to decrease their physical activity. Physical inactivity as well as social stress is known to be especially deleterious for heart failure (HF) patients. The BIO|STREAM.HF study enrolled such HF patients into a prospective registry with Home Monitoring.

Purpose

We aimed to evaluate the impact of the lockdown during the first Covid-19 pandemic wave on physical activity and arrhythmia burden of heart failure patients.

Methods

We analysed daily transmitted data of patients enrolled into a large international registry (BIO|STREAM.HF) being implanted with a cardiac resynchronization therapy (CRT) devices. Patients with NYHA ≥ II and LVEF ≤ 40% before CRT implantation were selected.

Intra-individual weekly mean and median values were calculated for the following daily transmitted parameters: physical activity (measured as % of the day during which the patient moves), atrial arrhythmia burden, mean heart rate (at rest), PP variability, PVC burden, and rate of biventricular pacing. Values were calculated for 12 weeks before and 12 weeks after the country-specific effective date of most rigorous restrictions in spring 2020 to visualize the general trend of parameter changes. Moreover, values for intra-individual changes between three 28-days periods (before, during, and after the lockdown) were calculated.

Results

Of 444 patients, 76% were male. They had a mean age of 69 ± 10 years and LVEF of 28.2 ± 6.7%. HF was of ischemic etiology in 42% of cases and they were in NYHA class II (47.5%), III (50.0%) or IV (2.5%).

On average, patients were active for 9% of the day (2 h 10 min). The physical activity decreased by approx. 10% with the onset of the lockdown (figure 1) and recovered within the following eight weeks.

Comparison of the 28-days periods before, during and after the lockdown showed a statistically significant intra-individual decrease in physical activity (mean decrease 9 min per day) during the lockdown compared to pre- and post-lockdown values and a trend toward reduced mean heart rates. In parallel, a significant increase in device detected atrial arrhythmia burden (mean increase 17 min per day) was observed. All other parameters did not change significantly.

Conclusion 

Our results show that patients reduced their physical activity during the Covid-19 related lockdown in spring 2020. This was associated with an increase in atrial arrhythmia burden and a reduction of the mean heart rate. Prognostic implications of these results will further be analysed.

Epicardial fat and the risk of atrial tachy-arrhythmia recurrence post pulmonary vein isolation: a computed tomography study

Epicardial and Pericardia fat have been hypothesized to exert local and systemic pathogenic effects on nearby cardiac structures. The present study aimed to evaluate the impact of epicardial and pericardial fat volumes on the outcome of patients that underwent a first pulmonary vein isolation (PVI) with cryoablation. We included 130 consecutive patients with atrial fibrillation (AF) that underwent contrast enhanced ECG-gated cardiac computed tomography (CCT) before a PVI. The control group included 50 patients in normal sinus rhythm that underwent ECG-gated CT to rule out coronary artery disease. Epicardial and pericardial fat volumes were quantified with CCT. Patients with AF compared to patients with normal sinus rhythm (control group) had significantly larger epicardial (140.3 ± 58.1 vs. 55.9 ± 17.7 ml; respectively, P < 0.001) and pericardial (77.0 ± 35.5 ml vs. 27.2 ± 9.5 ml; respectively, P < 0.001) fat volumes. Among patients that underwent PVIs, those with AF recurrence had a greater epicardial (175.0 ± 54.4 ml vs. 130.7 ± SD 54.2 ml; respectively, P < 0.001) and pericardial (93.7 ± SD 42.8 vs. 72.5 ± SD 31.9 ml; respectively, P < 0.001) fat volumes, compared to patients with no AF recurrence. Multivariate analyses revealed that epicardial fat was an independent predictor of recurrence post-ablation (HR = 1.08, 95% CI 1.02-1.16 per 10-ml increase in volume; P = 0.009). Pericardial fat was associated with 7% increase in risk of recurrent AF (HR = 1.07, 95% CI 0.98-1.18; P = 0.117). Epicardial fat, assessed with contrast enhanced CCT, is an independent predictor of AF recurrence after PVI ablation.

P6539Automated detection of atrial fibrillationb based on vocal features analysis

Background

Early identification of atrial fibrillation (AF) has been a long-standing clinical challenge and an unmet need. AF may be present without the patient being aware of any symptoms, leading to a delay in or failure of diagnosis. ESC guidelines recommend opportunistically screening patients >65 years of age using pulse palpation or an ECG rhythm strip, however these methods have limited effectivity. Analysis of natural speech signals has been used as a monitoring tool for various medical conditions and has recently been reported to enable estimation of heart rate. In this study we evaluated the efficacy of vocal features analysis in the detection of AF and in discriminating between sinus rhythm (SR) and episodes of AF.

Methods

In this prospective multicenter study, patients with persistent AF admitted for cardioversion were enrolled. A total of 86 patients in 2 centers were included. Prior to cardioversion, the patients spoke specific vowels and words according to a pre-specified protocol; an ECG tracing was simultaneously recorded. Following successful cardioversion and recovery from sedation, these recordings were repeated in SR. The recordings of the first 34 patients were used to develop an algorithm of AF detection based on analysis of acoustic features in SR and AF conditions. The algorithm was then validated in all of the patients (n=86) in the following manner: 25% of SR recordings were used to train the algorithm while the remaining 75% of SR and 100% of AF data from every patient were tested with the algorithm to distinguish between AF and SR.

Results

A total of 513 recordings from 86 patients were analyzed. Classification of the recordings as AF or SR was performed using varying cutoff values of the separation parameter. The resulting curve showing the specificity and sensitivity of the developed algorithm for distinguishing AF from SR is presented. Two specific examples of working points are a specificity of 92% and sensitivity of 83%, and a specificity of 82% and sensitivity of 92%.

Conclusions

This study demonstrates the feasibility of detecting AF and discriminating it from SR using analysis of acoustic features extracted from spoken vowels. The potential use of this method for wider population screening should be further evaluated.

Effect of fibrotic capsule debridement during generator replacement on cardiac implantable electronic device infection risk

BACKGROUND

Cardiovascular implantable electronic device (CIED) replacement is increasingly common. It has been proposed that capsule removal at the time of CIED replacement may reduce infection rates. In this study, we aimed to assess how pocket capsule removal impacted infection rates in patients undergoing CIED replacement.

METHODS

We retrospectively reviewed the medical records of patients who underwent CIED replacement from 2006 to 2016 at a single centre. We retrieved patient data, procedure details, and clinical outcomes. To evaluate the relationship between capsule removal and CIED infection, we used the Cox proportional hazard model, with adjustment for multiple variables.

RESULTS

During the study period, 773 patients underwent device replacement. Of these patients, 194 (25%) underwent capsule debridement during the replacement procedure. The mean patient age was 75 ± 15 years, and 281 (36.3%) were females. The replaced CIEDs included DDD pacemakers (32%), VDD pacemakers (15%), VVI/AAI pacemakers (13%), defibrillators (22%), and cardiac resynchronization therapy devices (CRT-D/P) (17%). During an average follow-up of 3.6 years, 42 (5%) patients experienced a CIED infection. Multivariate analysis revealed that patients who underwent capsule removal had a significantly lower risk of CIED infection, with a hazard ratio of 0.32 (95% confidence interval, 0.12-0.83; P = 0.019).

CONCLUSIONS

Capsule debridement during CIED replacement was associated with a significant reduction of CIED infection risk. There is a need for randomized controlled studies to confirm these findings.

Relation of Left Ventricular Fractional Shortening to Needfor Permanent Pacemaker After Transcatheter AorticValve Implantation

Transcatheter aortic valve implantation (TAVI) can potentially alter conduction system function due to the mechanical force applied to the conduction system by the proximal edge of the valve, particularly the CoreValve. Some reasons for post-TAVI advanced atrioventricular block have been identified. We investigated whether the degree of the motion of the basal left ventricular (LV) walls impacted the development of advanced atrioventricular block post-TAVI. A total of 407 patients (82.1 ± 6.2 years) without prior permanent pacemakers (PPMs) underwent TAVI using CoreValve (70%) or Edwards-SAPIEN (30%) prosthetic devices. The LV fractional shortening (FS) of the basal segments was measured in each patient, and the association between FS and PPM requirement, or new-onset left bundle branch block (LBBB) was evaluated. During hospitalization, 64 patients (15.7%) required PPM implantation, and 128 patients (31.4%) required PPM implantation or developed new LBBB. Independent predictors of PPM implantation included preprocedural right bundle branch block, CoreValve prosthetic device, valve implantation depth, and FS. Patients with high FS (≥40%, upper tertile) had a 2.5-fold increased risk of PPM implantation (p = 0.004) and a 1.8-fold increased risk of PPM or new LBBB (p = 0.020). Every 10% increment in FS was consistently associated with an adjusted 42% increased risk of PPM implantation (p = 0.015) and with an adjusted 43% increased risk of PPM implantation or new LBBB (p = 0.005). Thus, in our cohort, LV FS was independently associated with the need for PPM implantation during hospitalization. Hence, this simple echocardiographic measure can be used to identify patients who are at risk after TAVI.

Developing a risk score to predict mortality in the first year after implantable cardioverter defibrillator implantation: Data from the Israeli ICD Registry

INTRODUCTION

Life expectancy of less than 1 year is usually a contraindication for implantable cardioverter defibrillator (ICD) implantation. The aim was to identify patients at risk of death during the first year after implantation.

METHODS AND RESULTS

Data were derived from a prospective Israeli ICD Registry. Two groups of patients were compared, those who died and those who were alive 1 year after ICD implantation. Factors associated with 1-year mortality were identified on a derivation cohort. A risk score was established and validated. A total of 2617 patients have completed 1 year of follow-up after ICD or cardiac resynchronization therapy defibrillator (CRT-D) implantation. Age greater than 75 years (hazard ratio [HR], 2.7; 95% confidence interval [95% CI], 1.6 to 4.4), atrial fibrillation (AF; HR, 1.9; 95% CI, 1.12 to 3.17), chronic lung disease (HR, 2.0; 95% CI, 1.1 to 3.76), anemia (HR, 2.3; 95% CI, 1.3 to 3.93) and chronic renal failure (CRF; HR, 3.4; 95% CI, 1.74 to 6.6) were independent risk factors for 1-year mortality. We propose a simple AAACC ("triple A double C") score for prediction of 1-year mortality after ICD implantation: Age greater than 75 years (3 points(pts)), anemia (2 pts), AF (1 pt), CRF (3 pts) and chronic lung disease (1 pt). Mortality risk increased with rising number of points (from 1% with 0 pts to 12.5% with >4 pts). The risk score was evaluated with receiver operating characteristic curve and the area under the curve of the validation curve is 0.71 (95% CI, 0.66 to 0.76).

CONCLUSIONS

Age greater than 75, AF, chronic lung disease, anemia, and CRF were independent risk factors for 1-year mortality. AAACC risk score identifies patients at high risk of death during 1 year after ICD implantation.

Gender-Related Differences in Outcomes of Patients with Cardiac Resynchronization Therapy

BACKGROUND

Gender-related differences (GRD) exist in the outcome of patients with cardiac resynchronization therapy (CRT).

OBJECTIVES

To assess GRD in patients who underwent CRT.

METHODS

A retrospective cohort of 178 patients who were implanted with a CRT in a tertiary center 2005-2009 was analyzed. Primary outcome was 1 year mortality. Secondary endpoints were readmission and complication rates.

RESULTS

No statistically significant difference was found in 1 year mortality rates (14.6% males vs. 11.8% females, P = 0.7) or in readmission rate (50.7% vs. 41.2%, P = 0.3). The complication rate was only numerically higher in women (14.7% vs. 5.6%, P = 0.09). Men more often had CRT-defibrillator (CRT-D) implants (63.2% vs. 35.3%, P = 0.003) and had a higher rate of ischemic cardiomyopathy (79.2% vs. 38.2%, P < 0.001). There was a trend to higher incidence of ventricular fibrillation/ventricular tachycardia in men before CRT implantation (29.9% vs. 14.7%, P = 0.07%). A higher proportion of men upgraded from implantable cardioverter defibrillator (ICD) to CRT-D, 20.8% vs. 8.8%, P = 0.047. On multivariate model, chronic renal failure was an independent predictor of 1 year mortality (hazard ratio [HR] 3.6; 95% confidence interval [95%CI] 1.4-9.5), CRT-D had a protective effect compared to CRT-pacemaker (HR 0.3, 95%CI 0.12-0.81).

CONCLUSIONS

No GRD was found in 1 year mortality or readmission rates in patients treated with CRT. There was a trend toward a higher complication rate in females. Men were implanted more often with CRT-D and more frequently underwent upgrading of ICD to CRT-D.

Admission blood glucose and 10-year mortality among patients with or without pre-existing diabetes mellitus hospitalized with heart failure

BACKGROUND

High admission blood glucose (ABG) level has been associated with a poor short-term outcome among non-diabetic patients with heart failure (HF). We aimed to investigate the association between ABG levels and long-term (10 years) mortality in patients with or without pre-existing diabetes mellitus (DM) admitted with HF.

METHODS

We analyzed data on 1811 patients with DM and 2182 patients without pre-existing DM who were hospitalized with HF during a prospective national survey. The relationship between ABG and 10-year mortality was assessed using the Cox proportional hazard model adjusting for multiple variables. ABG was analyzed both as a categorical (<110, 110-140, 140-200, and >200 mg/dL) and as a continuous variable.

RESULTS

At 10 years of follow-up the cumulative probability of mortality was 85 and 78% among patients with DM and patients with no pre-existing DM (p < 0.001), respectively. Among patients with no pre-existing DM, glucose levels of 110-140, 140-200 and ≥200 mg/dL were associated with 9% (p = 0.140), 16% (p = 0.031) and 53% (p < 0.001) increased mortality risk compared to ABG < 110 mg/dL. Each 18-mg/dL (1-mmol/L) increase in glucose level was associated with a 5% increased risk of mortality (p < 0.001) among patients with no-pre-existing DM. In contrast, among patients with DM, only those with glucose levels >200 mg/dL had an increased mortality risk (>200 mg/dL versus <110 mg/dL; HR = 1.20, p = 0.032).

CONCLUSION

Among hospitalized HF patients with no pre-existing DM there is a linear relationship between ABG level and long-term mortality, whereas among patients with DM only ABG level >200 mg/dL is associated with increased mortality risk.

Syncope in Primary Prevention Implantable Cardioverter Defibrillator Implantation

BACKGROUND

Syncope prognosis varies widely: 1 year mortality may range from 0% in the case of vasovagal events up to 30% in the presence of heart disease.

OBJECTIVES

To assess the outcomes and prognosis of patients with implantable cardiac defibrillator (ICD) and indication of primary prevention and compare patients presenting with or without prior syncope.

METHODS

We reviewed the charts of 75 patients who underwent ICD implantation with the indication of primary prevention and history of syncope and compared them to a control group of 80 patients without prior syncope. We assessed the number of ventricular tachycardia (VT), ventricular fibrillation (VF), shock, anti-tachycardia pacing (ATP), and death in each group during the follow-up.

RESULTS

Mean follow-up was 893 days (810-976, 95% confidence interval) (no difference between groups). Patients with prior syncope had a higher ejection fraction (EF) (35.5 ± 12.6 vs. 31.4 ± 8.76, P = 0.02), more episodes of VT (21.3% vs. 3.8%, P = 0.001) and VF (8% vs. 0%, P = 0.01) and also received more electric shocks (18.7% vs. 3.8%, P = 0.004) and ATP (17.3% vs. 6.2%, P = 0.031). There were no differences in inappropriate shocks (6.7% vs. 5%, P = 0.74), in cardiovascular mortality (cumulative 5 year estimate 29.9% vs. 32.2% P = 0.97) and any death (cumulative 5 year estimate 38.1% vs. 48.9% P = 0.18) during the follow-up.

CONCLUSIONS

Syncopal patients before ICD implantation seem to have more episodes of VT/VF and shock or ATP. No mortality differences were observed.

Characteristics and outcomes of diabetic patients with an implantable cardioverter defibrillator in a real world setting: results from the Israeli ICD registry

Aims

There are limited data regarding the effect of diabetes mellitus (DM) on the risks of both appropriate and inappropriate implantable cardioverter defibrillator (ICD) therapy. The present study was designed to compare the outcome of appropriate and inappropriate ICD therapy in patients with or without DM.

Methods and results

The risk of a first appropriate ICD therapy for ventricular tachyarrhythmias (including anti tachycardia pacing and shock) was compared between 764 DM and 1346 non-DM patients enrolled in the national Israeli ICD registry. We also compared the risks of inappropriate ICD therapy, and death or cardiac hospitalization between diabetic and non-diabetic patients. Diabetic patients were older, were more likely to have ischemic cardiomyopathy, lower ejection fraction, atrial fibrillation, and other co-morbidities. The 3-year cumulative incidence of appropriate ICD therapy was similar in the DM and non-DM groups (12 and 13%, respectively, p = 0.983). Multivariate analysis showed that DM did not affect the risk of appropriate ICD therapy (HR = 1.07, 95% CI 0.78–1.47, p = 0.694) or inappropriate therapy (HR = 0.72, 95% CI 0.42–1.23, p = 0.232). However, DM was associated with a 31% increased risk for death or cardiac hospitalization (p = 0.005). Results were similar in subgroup analyses including ICD and defibrillators with cardiac resynchronization therapy function recipients, primary or secondary prevention indication for an ICD.

Conclusions

Despite a significant excess of cardiac hospitalizations and mortality in the diabetic population, there was no difference in the rate of ICD treatments, suggesting that the outcome difference is not related to arrhythmias.

Syncope in Primary Prevention Implantable Cardioverter Defibrillator Patients

BACKGROUND

Syncope is a common clinical condition spanning from benign to life-threatening diseases. There is sparse information on the outcomes of syncopal patients who received an implantable cardiac defibrillator (lCD) for primary prevention of sudden cardiac death (SCD).

OBJECTIVES

To assess the outcomes and prognosis of patients who underwent implantable cardiac defibrillator (ICD) implantation for primary prevention of SCD and compare them to patients who presented with or without prior syncope.

METHODS

We compared the medical records of 75 patients who underwent ICD implantation for primary prevention of SCD and history of syncope to those of a similar group of 80 patients without prior syncope. We assessed the episodes of ventricular tachycardia (VT), ventricular fibrillation (VF), shock, anti-tachycardia pacing (ATP) and mortality in each group during follow-up.

RESULTS

Mean follow-up was 893 days (810-976, 95% CI) (no difference between groups). There was no significant difference in gender or age. Patients with prior syncope had a higher ejection fraction rate (35.5 ? 12.6 vs. 31.4 8.76, P = 0.02), experienced more episodes of VT (21.3% vs. 3.8%, P = 0.001) and VF (8% vs. 0%, P = 0.01), and received more electric shocks (18.7% vs. 3.8%, P = 0.004) and ATP (17.3% vs. 6.2%, P = 0.031). There were no differences in inappropriate shocks (6.7% vs. 5%, P = 0.74), cardiovascular mortality (cumulative 5 year estimate 29.9% vs. 32.2%, P = 0.97) and any death (cumulative 5 year estimate 38.1% vs. 48.9%, P = 0.18).

CONCLUSIONS

Patients presenting with syncope before ICD implantation seemed to have more episodes of VT/VF and shock or ATP. No differences in mortality were observed.

Type of Atrial Fibrillation and Clinical Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND

There are limited data available regarding the relationship between atrial fibrillation (AF) clinical type, oral anticoagulation (OAC) treatment, and clinical outcome after transcatheter aortic valve replacement (TAVR). The study was designed to evaluate this relationship.

METHODS

We analyzed data from the Rabin Medical Center TAVR registry, including 319 consecutive patients who underwent TAVR from 2008 to 2014. Patients were divided into three groups based on their history of AF: sinus rhythm (SR), paroxysmal AF (PAF), or nonparoxysmal AF (NPAF).

RESULTS

There were 211 (66%), 56 (18%), and 52 (16%) patients in the SR, PAF, and NPAF groups, respectively. The cumulative risk for stroke or death at 2 years was highest among patients with NPAF (38%), but similarly low in PAF (15%) and SR patients (16%, P < 0.001). By multivariate analysis, patients with NPAF demonstrated a significantly higher risk of stroke or death (HR = 2.76, 95% CI 1.63-4.66, P < 0.001), as compared with SR. In contrast, patients with PAF had a similar risk of stroke or death compared with SR (HR = 0.80, P = 0.508). Patients with NPAF not treated with OAC demonstrated an 8.3-fold (P < 0.001) increased risk of stroke or death, whereas patients with PAF not treated with OAC had a similar risk of stroke or death compared with the SR group (HR = 1.25, P = 0.569).

CONCLUSION

History of NPAF, but not PAF, is associated with a significant increased risk of stroke or death compared with sinus rhythm in patients undergoing TAVR.

Association between Red Cell Distribution Width and Mortality after Cardiac Resynchronization Therapy

BACKGROUND

Cardiac resynchronization therapy (CRT) is a non-pharmacological option for patients with heart failure and interventricular dyssynchrony. Elevated red cell distribution width (RDW) reflects higher size and heterogeneity of erythrocytes and is associated with poor outcome in patients with chronic heart failure.

OBJECTIVES

To examine the association between RDW levels and outcomes after CRT implantation.

METHODS

We conducted a cohort analysis of 156 patients (126 men, median age 69.0 years) who underwent CRT implantation in our institution during 2004-2008. RDW was measured at three time points before and after implantation. Primary outcome was defined as all-cause mortality, and secondary outcome as hospital re-admissions. We investigated the association between RDW levels and primary outcome during a median follow-up of 61 months.

RESULTS

Ninety-five patients (60.9%) died during follow-up. Higher baseline RDW levels were associated with all-cause mortality (unadjusted HR 1.35, 95% CI 1.20-1.52, P < 0.001). On multivariate analysis adjusted for clinical, electrocardiographic and laboratory variables, baseline RDW levels were associated with mortality (HR 1.33, 95%CI 1.16-1.53). RDW levels 6 months and 12 months post-implantation were also associated with mortality (HR 1.22, 95%CI 1.08-1.38, P = 0.001; and HR 1.15, 95% CI 1.01-1.32, P = 0.02, respectively). Patients who were re-admitted to hospital during follow-up (n = 78) had higher baseline RDW levels as compared to those who were not (14.9%, IQR 14.0, 16.0% vs. 14.3%, IQR 13.7, 15.0%, respectively, P = 0.03).

CONCLUSION

An elevated RDW level before and after CRT implantation is independently associated with all-cause mortality.

Ethnic differences among implantable cardioverter defibrillators recipients in Israel

Heart failure is an increasingly common condition arising from a variety of different pathophysiological processes. Little is known about the unique features of Israeli Arabs who present with heart failure and who undergo cardiac device implantation. The study population comprised of 4,671 patients who were enrolled in the national Israeli Implantable Cardioverter Defibrillator registry. We compared demographic, clinical, and echocardiographic characteristics; device-related indications; and outcomes between Israeli Arabs (n = 733) and Jews (n = 3,938), who were enrolled in the registry from July 2010 through December 2013. Israeli Arabs constituted 15.7% of the study population. They were younger at presentation compared with Jews (57 ± 15 vs 66 ± 12 years, respectively; p <0.001), with a greater burden of co-morbidities, including diabetes mellitus and chronic obstructive lung disease and smoking. In addition, Arab patients had a greater frequency of non-ischemic cardiomyopathy (40.2% vs 24.6%, respectively; p <0.001), which was associated with a greater frequency of familial history of sudden cardiac death. During 15 ± 9 month follow-up, the mortality rates and appropriate device therapy were similar in both ethnic groups. In conclusion, Israeli Arab patients implanted with implantable cardioverter defibrillators display unique clinical features with greater prevalence of non-ischemic cardiomyopathy characterized by an early-onset and rapid deterioration.

Association of time of occurrence of electrical heart storms with environmental physical activity

AIM

Many publications in recent decades have reported a temporal link between medical events and environmental physical activity. The aim of this study was to analyze the time of occurrence of electrical heart storms against levels of cosmological parameters.

METHODS

The sample included 82 patients (71 male) with ischemic cardiomyopathy treated with an implantable cardioverter defibrillator at a tertiary medical center in 1999-2012 (5,114 days). The time of occurrence of all electrical heart storms, defined as three or more events of ventricular tachycardia or ventricular fibrillation daily, was recorded from the defibrillator devices. Findings were analyzed against data on solar, geomagnetic, and cosmic ray (neutron) activity for the same time period obtained from space institutions in the United States and Russia.

RESULTS

Electrical storms occurred in all months of the year, with a slight decrease in July, August, and September. Most events took place on days with lower-than-average levels of solar and geomagnetic activity and higher-than-average levels of cosmic ray (neutron) activity. There was a significant difference in mean daily cosmic ray activity between the whole observation period and the days of electrical storm activity (P = 0.0001).

CONCLUSION

These data extend earlier findings on the association of the timing of cardiac events and space weather parameters to the most dangerous form of cardiac arrhythmia-electric storms. Further studies are needed to delineate the pathogenetic mechanism underlying this association.

Prinzmetal angina in the differential diagnosis of syncope

Prinzmetal (variant) angina may be associated with cardiac arrhythmias that can deteriorate to fatal ventricular arrhythmias. We present 2 patients with syncope where vasospastic angina and severe ventricular arrhythmias were found to be responsible for the syncopal episodes.

Electrogram-based optimal atrioventricular and interventricular delays of cardiac resynchronization change individually during exercise

BACKGROUND

Limited data suggest that optimal atrioventricular (AV) and interventricular (VV) delays are different at rest than during exercise in patients with heart failure. We assessed the feasibility and reproducibility of an electrogram-based method of optimization called QuickOpt at rest and during exercise.

METHODS

Patients with a St Jude Medical cardiac resynchronization therapy implantable cardioverter-defibrillator were subjected to a graded treadmill test, and QuickOpt was repeatedly measured prior to, during, and after the exercise.

RESULTS

Twenty-four patients (16 males, aged 67.4 ± 7.7 years) participated. At rest, delays (in ms) were 110.4 ± 20.1 for sensed AV delay and -70 (LV pacing first) to +20 (RV pacing first) for VV delay. The changes in QuickOpt-derived delays at rest were not significant despite change in body position. During exercise, QuickOpt-derived AV delays did not change in 11 patients, were shorter during peak exercise in 8 patients, and were longer in 3 patients (average value during peak exercise was 126.5 ± 15.8 ms, P = 0.04 compared to baseline). The QuickOpt-derived VV delay gradually shifted toward earlier right ventricular pacing during exercise in 19 patients, while no changes were seen in 3 patients, and a shift occurred toward earlier left ventricular pacing in 2 patients (average value during peak exercise was -30.7 ± 22.2; P = 0.001 compared to baseline). There was no correlation between changes in the QuickOpt-derived AV and VV delays and heart rate.

CONCLUSIONS

The application of electrogram-based algorithm is feasible both at rest and during exercise. The results are reproducible. QuickOpt-derived AV and VV delays individually change during exercise.

Acute and intermediate‐term results of percutaneous coronary stenting in octogenarian patients

BACKGROUND

Percutaneous coronary intervention (PCI) in octogenarian patients has been associated with increased cardiovascular morbidity and mortality. This study aimed to assess acute and intermediate-term clinical outcomes among octogenarians undergoing PCI.

METHODS

The authors identified 97 consecutive patients aged > or =80 years who underwent PCI using stents between November 2000 and February 2002 at their institution. The patients were divided into three groups according to clinical presentation: (1) acute myocardial infarction (AMI, n = 31); (2) unstable angina pectoris (UAP, n = 28); and (3) stable angina pectoris (SAP, n = 38). Procedural data, and in-hospital and six-month clinical outcomes were obtained and adjudicated for all patients.

RESULTS

Overall mean age was 84 +/- 3 years, 67% of patients were males and 73% had multivessel coronary disease. In-hospital outcomes varied according to clinical presentation: procedural success was 78% in AMI patients (including shock patients), 93% in UAP, and 95% in SAP patients. Likewise, hospital mortality was 26% in AMI, 3.6% in UAP, and 0% in SAP patients (p = 0.0003). Among AMI patients, hospital mortality was extremely high in patients with cardiogenic shock (67% versus 4.6% in AMI without shock, p < 0.0001). Cumulative event rate at six months also varied according to clinical presentation: mortality/MI and target vessel revascularization (TVR) rates were 29%, 3.6%, and 0% in AMI, 7.1%, 7.4%, and 11% in UAP and 0%, 5.3%, and 7.9% in SAP patients. Multivariate analysis identified cardiogenic shock as the most powerful risk factor for predicting mortality (odds ratio = 42, p = 0.03).

CONCLUSIONS

These results show that clinically stable octogenarian patients undergoing PCI have favorable procedural and intermediate-term prognosis. In contrast, cardiogenic shock has a profound negative prognostic impact on octogenarians despite 'aggressive' PCI attempts.

Temporal relationship of implantable cardioverter defibrillator discharges and environmental physical activity

BACKGROUND

Studies by our group have shown an inverse relationship between sudden death and cardiac rhythm disturbances and environmental levels of geomagnetic activity (GMA). The aim of this study was to use the precise data provided by automatic implantable cardioverter defibrillators (ICDs) regarding the onset of ventricular fibrillation and ventricular tachycardia to link these events to GMA level.

PATIENTS AND METHODS

The study group included 25 patients (22 men; 22 with ischemic cardiomyopathy) aged 28-81 years in whom an ICD had been implanted between 1995 and 2004. Patients were referred to the cardiac intensive care unit after each event that induced one or more discharges. The number of events and the day on which they occurred were recorded. Data on GMA and other cosmophysical parameters were obtained from the U.S. National Geophysical and Space Service Centers and the Russian Academy of Sciences. GMA levels, graded from I (quiet) to IV (stormy) in the middle latitutes, were recorded for 1974-2003 (10,954 days) and for each day on which an ICD discharge occurred.

RESULTS

A total of 402 discharges were recorded on 137 days during the study period. Forty-six percent of the discharges took place on days of GMA I, compared with 38% - II, 13% - III, and 3% - IV. The daily distribution of GMA was as follows: level I - 35.2%, II - 37.3%, III - 21.86%, IV - 5.61%. Comparison of ICD discharge days and actual multiyear levels of GMA (in percent) yielded a ratio of 1.326 for GMA I, 1.076 - II, 0.459 - III, 0.390 - IV. There was a significant inverse correlation between GMA level and number of discharges (r =-0.97, P = 0.03) and days of treatment (r =-0.96, P = 0.039), and a significant difference between ICD discharges on days of GMA I and GMA II-IV (chi(2)= 5.05, P = 0.02).

CONCLUSION

The higher number of ICD discharges on days of lowest GMA may be explained by a possible antiarrhythmic effect of GMA. Environmental arrhythmogenic factors that act inversely to GMA may be activated at times of low GMA.

Are neutrons involved in the pathogenesis of life-threatening cardiac arrhythmias?

Geomagnetic fields protect the earth from the adverse effects of cosmic rays, whose activity can be indirectly measured by monitoring the level of neutrons in the environment. The number and days of discharges from automatic implantable cardioverter defibrillators (ICD) in patients with cardiac arrhythmias are inversely correlated with the daily level of geomagnetic activity (GMA). The aim of the present was to determine whether neutron levels on days of AICD discharges are higher than average. Days on which discharges occurred were recorded in 31 patients bearing ICDs for managing ischemic cardiomyopathy. Daily neutron levels obtained from the monitoring data of the Russian Academy of Sciences in Moscow were analyzed using Student's t test. The mean (+/-SD) daily neutron level for the 1096-day period was 8299.29 +/- 294.236 imp/min (median 8252), and for days of ACID discharge, 8423.93 +/- 274.187 imp/min (median 8443) (p = 0.0002). The mean neutron activity on days of AICD discharges in response to ventricular disturbances was significantly higher than the mean level over the 1096-day study period. Whether this relation is a direct result of low GMA or due to an independent role of neutrons in the pathogenesis and timing of cardiac arrhythmias is unknown.

Atrial Flutter After Surgical Radiofrequency Ablation of the Left Atrium for Atrial Fibrillation

BACKGROUND

Left atrial radiofrequency ablation is the most common technique for the treatment of atrial fibrillation during mitral valve surgery. Reported failure rates range between 15% and 30%, with some patients remaining in atrial fibrillation and others experiencing atrial flutter. The incidence and nature of the postoperative atrial flutter is not yet well defined.

METHODS

The study group consisted of 50 patients with atrial fibrillation who underwent mitral valve surgery combined with left atrial radiofrequency ablation, and were followed for a mean period of 15 +/- 7 months. The majority of patients (39; 78%) had persistent or permanent atrial fibrillation. Placement of the ablation lines was as follows: encircling the pulmonary veins, isolating the base of the left atrial appendage, and bridging the lateral or posterior mitral annulus and the margin of the pulmonary vein or the appendage-encircling ablation lines.

RESULTS

There were three hospital deaths (6%). Thirty-four (72%) patients were free of any atrial tachyarrhythmia events, and 37 (79%) patients were in sinus rhythm by the end of the study's follow-up. During the follow-up, 6 patients (12.7%) experienced atrial flutter and 1 patient had atrial tachycardia. Electrophysiologic study was performed in 5 of 6 patients with postoperative atrial flutter. In 4 of them, the study findings were consistent with left atrial flutter. One patient with typical isthmus-dependent right atrial flutter underwent successful ablation.

CONCLUSIONS

Left atrial surgical radiofrequency ablation is associated with a high rate of postoperative atrial flutters that appear to be predominantly of left-sided origin.

Atrial Signal Amplitude Measurements in VDD Systems According to Body Position

Single lead VDD pacing is an established therapy in patients with AV block. Body position may influence the amplitude of the atrial signal recorded through the floating atrial electrode. This study analyzed the degree of posture related variation in the signal amplitude of floating atrial electrodes in 63 patients (mean age 72 +/- 21 years) implanted with a VDD system. The average atrial amplitude in the supine position was 1.59 +/- 1.15 mV and decreased significantly in the sitting position (1.37 +/- 1.08, P < 0.014), right decubitus (1.33 +/- 0.83, P < 0.007), and the abdominal position (1.24 +/- 0.86, P < 0.001). The left side decubitus showed a nonsignificant increase in atrial amplitude (1.66 +/- 1.02, P < 0.64). Body position significantly affects P wave amplitude and may be the cause of intermittent atrial undersensing. P wave amplitude measurement in different body postures should be performed in cases where suspected atrial undersensing occurs.

Acute and intermediate-term results of percutaneus left main coronary artery interventions

BACKGROUND

Left main coronary artery disease is considered a surgical indication in most centers. However, in some cases prohibited from surgery or in patients with prior bypass grafting, there is a need for percutaneous coronary intervention in LMCA disease scenarios.

OBJECTIVES

To assess the clinical outcomes among patients undergoing stent-based LMCA angioplasty.

METHODS

We identified 34 consecutive patients who underwent PCI in LMCA at our institution. Procedural data and clinical outcomes were obtained for all patients.

RESULTS

The mean age was 71 +/- 12 years. There were 27 elective and 7 emergent procedures performed on 23 "protected" LMCA and 11 "unprotected" LMCA. In emergent procedures, the prevalence of cardiogenic shock (29% vs. 0%, P = 0.04) in patients with prior coronary bypass (29% vs. 8.5%, P = 0.007) was significantly higher compared to elective cases. Procedural success in emergent procedures was significantly lower than in elective procedures (71 vs. 100%, P = 0.04). In emergent versus elective procedures, the in-hospital mortality rate was higher (43 vs. 0%, P = 0.006). The rate of cumulative major adverse cardiac events at 1 and 6 months was 43% and 71% in emergent cases versus 0% and 33% in elective cases (P < 0.05 for both comparisons). In patients with "unprotected" LMCA the overall rate of major cardiac events at 1 month was higher compared to "protected" LMCA patients (27 vs. 0%, P = 0.02). Multivariate analysis revealed emergent procedure as an independent predictor for mortality and adverse cardiac events (odds ratio 6.7, 95% confidence interval 1.2-36; P = 0.02).

CONCLUSIONS

Percutaneous interventions in LMCA are feasible and relatively safe in carefully selected cases. Procedural outcomes and clinical prognosis is highly dependent on the nature of disease prior to angioplasty (e.g., elective vs. emergent procedure) as well as on protection of the LMCA by patent grafts.

Augmentation of low-frequency ultrasound-induced clot disruption by hydroxyethyl starch is dependent on the duration and intensity of ultrasound exposure; an in vitro study

We investigated the synergistic effect between low-frequency ultrasound (US) and hydroxyethyl starch (HAES) on blood clot disruption, using different HAES concentrations, US duration and intensity. Human blood clots, 200 to 400 mg in weight, were placed in tubes containing 10 mL of normal saline alone or with HAES 0.1%, 1% or 2%. Clots were randomized to four intensities of US exposure: none, low, medium and high (maximal amplitude of motion at the tip of the horn: 0, 96, 144 and 192 micro m, respectively), and for three durations of US exposure (10, 20 and 40 s). After treatment, the clots were reweighed, and the percent differences in weights were calculated. US intensity, US duration and HAES concentration had a significant effect on the blood clot dissolution (p < 0.001 for all three variables). HAES augmented clot dissolution only when US intensity was medium or high. With low intensity, HAES did not augment clot lysis.

CONCLUSIONS

microparticle-containing solutions, such as HAES, have a potential for augmenting clot disruption by US. This effect is highly dependent on US intensity.

Correlation between the electrocardiogram and regional wall motion abnormalities as detected by echocardiography in first inferior acute myocardial infarction

We assessed the correlation between ST deviation in each of the six precordial leads and the presence of regional wall motion abnormalities (RWMA) as assessed by transthoracic echocardiography in 109 patients with first inferior acute myocardial infarction. ST depression in lead V1 and V2 was associated with higher incidence of RWMA of the mid-posterior segment (p < 0.02 for both leads). The specificity of ST segment depression in leads V1 and V2 for RWMA in mid-posterior segment was 87 and 57%, and the sensitivity 36 and 70%, respectively. Patients with ST depression in leads V2 or V3 had worse global RWMA score than patients without ST depression in these leads (p = 0.009 and p = 0.025, respectively). Patients with an ST elevation in lead V1, but not in leads V2 or V3, had a higher prevalence of right ventricular involvement (p < 0.0001). ST elevation in lead V5 was associated with more frequent involvement of the apical portion of the inferior wall (p < 0.02), with specificity of 88% and sensitivity of 33%. Global RWMA score was significantly worse for patients with ST elevation than for patients with isoelectric ST in lead V5 (p = 0.024). ST elevation in lead V6 was associated with RWMA in the mid-posterior segment (p < 0.006), with specificity of 91% and sensitivity of 33%, and worse global RWMA score (p = 0.022).

Implantable cardioverter defibrillators in Israel: utilization and implantation trends

BACKGROUND

Since its introduction, the implantable cardioverter defibrillator (ICD) has evolved to its present status as the dominant therapeutic modality for patients with life-threatening arrhythmias. Several randomized studies have shown the benefit of ICD implantation as the first choice of treatment for primary as well as secondary indications for ventricular arrhythmias. Therefore, it is expected that the use of ICDs will increase further. The main objectives of this study were to analyze the Israeli experience with ICD implantation from 1993 to 1999, to examine the diffusion of ICD therapy in Israel and the evolution of implantation patterns and indications.

METHODS

We conducted a retrospective review and analysis of an ICD registry for the period of January 1993-December 1999. Data collected included demographic, administrative, clinical and survival data.

RESULTS

A total of 732 new implantations were identified and reviewed. The mean length of follow up of all patients was 30.7+/-21.1 months. 86% of patients were males and the mean age at implantation was 62.6+/-12.4 years. 79% of patients had CAD and the mean EF of all patients was 29.2+/-11.2%. 135 patients (18.4%) died during follow-up. One, two and three-year survival rates were calculated and were 92.7%, 87.8% and 82.0% respectively. A steady increase in implantation rate and in implanting centers was observed over the years.

CONCLUSIONS

ICD therapy is relatively expensive; therefore a national registry which is continuously monitored may be the most expedient method to follow clinical and economic aspects of the utilization of this therapeutic modality.

There is synergism between high-intensity, low-frequency ultrasound and streptokinase but not with eptifibatide, heparin, and aspirin. Differential effects on fresh and aged blood clots. An in vitro study

OBJECTIVE

Ultrasound is emerging as a promising modality for recanalization of acutely thrombosed blood vessels, especially when associated with fibrinolytics. We assessed the efficacy of ultrasound combined with saline, heparin, eptifibatide, aspirin, and streptokinase in disruption of fresh as well as aged human blood clots, using an in vitro model.

METHODS

Blood clots from five donors, 2-4 or 48 hours old, were cut into 250-400 mg slices and immersed for 1, 15, or 30 min in 10 ml saline containing either heparin, eptifibatide, aspirin, streptokinase, or saline alone. Clots were then randomized to 10 s of 20 kHz ultrasound or immersion alone. After treatment, the percentage difference in weight was calculated.

RESULTS

Immersion of fresh clots without ultrasound in eptifibatide and heparin resulted in significantly more clot lysis than immersion in saline, aspirin, and streptokinase. Immersion of aged thrombi without ultrasound in heparin, eptifibatide, and aspirin had no additive effect over immersion in saline. Ultrasound enhanced clot disruption in all five solutions, in each immersion time and both in fresh and aged clots. Heparin and aspirin had no additive effect, compared with saline, on ultrasound disruption of both fresh and aged clots, whereas eptifibatide was less effective than saline. In contrast, streptokinase greatly enhanced disruption of both fresh (P=.004) and aged (P<.001) thrombi by ultrasound. The combinations of ultrasound with saline, heparin, eptifibatide, and aspirin were less effective on aged than fresh thrombi, whereas the combination of ultrasound with streptokinase was equally effective on fresh and aged thrombi.

CONCLUSIONS

Using a simple in vitro model, we found that the combination of streptokinase and low-frequency ultrasound had a synergistic effect on disruption of both fresh and aged blood clots. Further studies are needed to assess the role of heparin and antiplatelet agents in augmenting clot disruption by ultrasound in in vivo models of acute and subacute thrombosis.

The effects of streptokinase and hydroxyethyl starch on in vitro clot disruption by ultrasound

BACKGROUND

In vitro studies showed that low-frequency ultrasound (US) causes blood clot dissolution. This effect is augmented with thrombolytics, microbubbles and microparticles. However, in animal models of transcutaneous delivery, US alone is not effective, probably due to attenuation of US energy by overlying skin. When combined with thrombolytics or microbubbles, transcutaneous US is highly effective.

PURPOSE

To assess the synergistic effect of low-intensity low-frequency US and saline, hydroxyethyl starch (HAES) (a non-gas filled microparticle containing solution), streptokinase (STK), and their combination on blood clot disruption.

METHODS

Human blood clots from 4 healthy donors, 2-4 hours old, were immersed for 0, 15, or 30 min in 37 degrees C in 10 ml of the above-mentioned solutions, and then were randomized to 10 sec of 20 kHz US or no US. The % difference in weight was calculated.

RESULTS

Immersion for 30 min without US resulted in 13.8 +/- 1.2% clot lysis in saline, and 22.0 +/- 1.3%, 21.7 +/- 2.1%, and 23.2 +/- 1.9% in STK, HAES, and STK + HAES, respectively (p = 0.002). US augmented clot lysis in all groups and at all time points. With low-intensity US, HAES was not better than saline. However, the combination of HAES + STK with US resulted in larger clot disruption at 15 sec incubation time (46.7 +/- 3.2%) than with saline (29.6 +/- 2.1%), HAES (29.6 +/- 2.5%), and STK (32.8 +/- 3.6%) (p < 0.001).

CONCLUSION

low-frequency, low-intensity US combined with HAES and STK resulted in greater clot disruption at short incubation times. This combination may assist in achieving faster reperfusion in in vivo models.