[The biomarkers BNP and NT-proBNP]

The present review of the biomarkers BNP and NT-pro-BNP is published in the series "biomarkers" of the Zentralblatt für Arbeitsmedizin, Arbeitsschutz und Ergonomie, which deals with the increasing use of the determination of specific markers in so-called manager preventive and check-up examinations. In principle, BNP and NT-pro-BNP are fundamentally suitable as markers for diagnosing acute and chronic heart failure and for assessing the course. In this context these show a high sensitivity and specificity.

Improved Physical Function After Cardiac Contractility Modulation Therapy in 10 Patients With Chronic Heart Failure

BACKGROUND

A new generation of therapeutic devices has expanded the options for managing advanced heart failure. We examined the outcomes of cardiac contractility therapy in a series of 10 patients with chronic heart failure.

METHODS

Ten patients with chronic heart failure were nonrandomly selected to receive cardiac contractility modulation therapy. Hemodynamics, left ventricular ejection fraction, functional capacity, and clinical outcomes were evaluated at baseline and after 6 months of therapy.

RESULTS

Eight male and 2 female patients (mean [SD] age, 63.4 [9.4] years) received cardiac contractility modulation therapy. Between baseline and 6-month follow-up, mean (SD) left ventricular ejection fraction improved from 27.1% (4.18%) to 35.1% (9.89%), New York Heart Association class declined from 3.9 (0.32) to 2.44 (0.52), and 6-minute walk test distance increased from 159.2 (93.79) m to 212.4 (87.24) m. Furthermore, the mean (SD) number of hospital admissions within the 6 months before cardiac contractility modulation therapy was 2.4 (2.27) compared with 1 (1.52) during the 6 months after therapy.

CONCLUSION

Cardiac contractility modulation therapy improved physical functioning and reduced hospital admissions in these patients.

Reimbursement practices for use of digital devices in atrial fibrillation and other arrhythmias: a European Heart Rhythm Association survey

AIMS

Since digital devices are increasingly used in cardiology for assessing cardiac rhythm and detecting arrhythmias, especially atrial fibrillation (AF), our aim was to evaluate the expectations and opinions of healthcare professionals in Europe on reimbursement policies for the use of digital devices (including wearables) in AF and other arrhythmias.

METHODS AND RESULTS

An anonymous survey was proposed through announcements on the European Heart Rhythm Association website, social media channels, and mail newsletter. Two hundred and seventeen healthcare professionals participated in the survey: 32.7%, reported regular use of digital devices, 45.2% reported that they sometimes use these tools, 18.6% that they do not use but would like to. Only a minority (3.5%) reported a lack of trust in digital devices. The survey highlighted a general propensity to provide medical consultation for suspected AF or other arrhythmias detected by a consumer-initiated use of digital devices, even if time constraints and reimbursement availability emerged as important elements. More than 85% of respondents agreed that reimbursement should be applied for clinical use of digital devices, also in different settings such as post-stroke, post-cardioversion, post-ablation, and in patients with palpitations or syncope. Finally, 73.6% of respondents confirmed a lack of reimbursement fees in their country for physicians' consultations (tracings interpretation) related to digital devices.

CONCLUSIONS

Digital devices, including wearables, are increasingly and widely used for assessing cardiac rhythm and detecting AF, but a definition of reimbursement policies for physicians' consultations is needed.

Telemedicine in Cardiology: Modern Technologies to Improve Cardiovascular Patients’ Outcomes—A Narrative Review

The registration of physical signals has long been an important part of cardiological diagnostics. Current technology makes it possible to send large amounts of data to remote locations. Solutions that enable diagnosis and treatment without direct contact with patients are of enormous value, especially during the COVID-19 outbreak, as the elderly require special protection. The most important examples of telemonitoring in cardiology include the use of implanted devices such as pacemakers and defibrillators, as well as wearable sensors and data processing units. The arrythmia detection and monitoring patients with heart failure are the best studied in the clinical setting, although in many instances we still lack clear evidence of benefits of remote approaches vs. standard care. Monitoring for ischemia is less well studied. It is clear however that the economic and organizational gains of telemonitoring for healthcare systems are substantial. Both patients and healthcare professionals have expressed an enormous demand for the further development of such technologies. In addition to these subjects, in this paper we also describe the safety concerns associated with transmitting and storing potentially sensitive personal data.

[Modulation of cardiac contractility in patients with chronic heart failure and atrial fibrillation]

AIM

to evaluate the effectiveness of cardiac contractility modulation (MSS) in patients with chronic heart failure (CHF) and atrial fibrillation (AF).

MATERIALS AND METHODS

The following studies were performed in 40 patients with CHF and AF before implantation of the MSS device and after 2 and 6 months of follow-up: 12-channel ECG, transthoracic EchoCG, 6-minute walk test, determination of the level of Pro-natriuretic N-terminal peptide (NT-proBNP), daily ECG monitoring, and a questionnaire based on the Minnesota quality of life questionnaire for patients with CHF (MHFLQ). All patients received long-term optimal drug therapy for CHF before surgery.

RESULTS

The results obtained indicate a statistically significant positive effect of the use of MSS in patients with CHF and AF on LV FV, the functional class of CHF, and levels of NT-proBNP regardless of the etiology of CHF.

CONCLUSION

The use of MSS may be promising for the treatment of heart failure in patients with CHF and AF.

[Cardiac contractility modulation for treatment of chronic heart failure]

The worldwide prevalence of heart failure is 1-2% with a portion of >10% in patients older than 70 years. In addition to treatment of causal determined factors and lifestyle modification, basic treatment consists of guideline-directed medical therapy with angiotensin-converting enzyme inhibitors (ACE), β‑blockers (BB), mineralocorticoid receptor antagonists (MRA), diuretics, digitalis (class IIb recommendation), angiotensin receptor blockers (ARB), Iƒ-channel blockers plus recently recommended in the guidelines angiotensin receptor neprilysin inhibitor (ARNI) to substitute the ACE inhibitor (class I b). Cardiac contractility modulation (CCM) is a device-based electrical therapy for the treatment of refractory heart failure symptoms. CCM signals are relatively high intensity, nonexcitatory signals applied during the absolute refractory period that have been shown to enhance the strength of left ventricular (LV) contraction and improve exercise tolerance and quality of life. The mechanisms of action appear to involve effects on myocardial gene expression and normalization of myocardial key-proteins. So far, more than 3500 CCM devices have been implanted worldwide. For patients with symptomatic heart failure and narrow QRS complex, CCM is together with baroreceptor activation the only additive electrical therapy which had been approved in Germany. Actually, for the first time, CCM has been referenced in the current Heart Failure Guidelines. Prognostic data with regard to mortality are currently being evaluated in case series; some of which have since been published. Approval by the US Food and Drug Administration (FDA) is expected within the next months.

[Cardiac contractility modulation]

Cardiac contractility modulation (CCM) is a device-based electrical therapy for the additive treatment of chronic drug-refractory heart insufficiency. High-amplitude signals are applied during the absolute refractory period and have been shown to enhance the strength of left ventricular (LV) contraction and improve exercise tolerance and quality of life. The mechanisms of action appear to involve effects on myocardial gene expression and on normalization of key myocardial proteins. So far, more than 3500 CCM devices have been implanted worldwide. For patients with therapy refractory heart insufficiency and narrow QRS complex, CCM is together with baroreceptor activation the only additive electrical therapy which had been approved in Germany. For the first time CCM has been referenced in the current guidelines on cardiac insufficiency. Prognostic data with respect to mortality have been evaluated in case series. Ongoing randomized trials and registries will address these specific endpoints and have to a significant extent already been recently published. A Food and Drug Administration (FDA) approval is expected within the next few months.

Long-term results of combined cardiac contractility modulation and subcutaneous defibrillator therapy in patients with heart failure and reduced ejection fraction

BACKGROUND

Cardiac contractility modulation (CCM) is an electrical-device therapy for patients with heart failure with reduced ejection fraction (HFrEF). Patients with left ventricular ejection fraction (LVEF) ≤35% also have indication for an implantable cardioverter-defibrillator (ICD), and in some cases subcutaneous ICD (S-ICD) is selected.

HYPOTHESIS

CCM and S-ICD can be combined to work efficaciously and safely.

METHODS

We report on 20 patients with HFrEF and LVEF ≤35% who received CCM and S-ICD. To exclude device interference, patients received intraoperative crosstalk testing, S-ICD testing, and bicycle exercise testing while CCM was activated. Clinical and QOL measures before CCM activation and at last follow-up were analyzed. S-ICD performance was evaluated while both CCM and S-ICD were active.

RESULTS

Mean follow-up was 34.3 months. NYHA class improved from 2.9 ± 0.4 to 2.1 ± 0.7 (P < 0.0001), Minnesota Living With Heart Failure Questionnaire score improved from 50.2 ± 23.7 to 29.6 ± 22.8 points (P < 0.0001), and LVEF improved from 24.4% ± 8.1% to 30.9% ± 9.6% (P = 0.002). Mean follow-up time with both devices active was 22 months. Three patients experienced a total of 6 episodes of sustained ventricular tachycardia, all successfully treated with first ICD shock. One case received an inappropriate shock unrelated to the concomitant CCM. One patient received an LVAD, so CCM and S-ICD were discontinued.

CONCLUSIONS

CCM and S-ICD can be successfully combined in patients with HFrEF. S-ICD and CCM remain efficacious when used together, with no interference affecting their function.

Heart failure

Heart failure is common in adults, accounting for substantial morbidity and mortality worldwide. Its prevalence is increasing because of ageing of the population and improved treatment of acute cardiovascular events, despite the efficacy of many therapies for patients with heart failure with reduced ejection fraction, such as angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), β blockers, and mineralocorticoid receptor antagonists, and advanced device therapies. Combined angiotensin receptor blocker neprilysin inhibitors (ARNIs) have been associated with improvements in hospital admissions and mortality from heart failure compared with enalapril, and guidelines now recommend substitution of ACE inhibitors or ARBs with ARNIs in appropriate patients. Improved safety of left ventricular assist devices means that these are becoming more commonly used in patients with severe symptoms. Antidiabetic therapies might further improve outcomes in patients with heart failure. New drugs with novel mechanisms of action, such as cardiac myosin activators, are under investigation for patients with heart failure with reduced left ventricular ejection fraction. Heart failure with preserved ejection fraction is a heterogeneous disorder that remains incompletely understood and will continue to increase in prevalence with the ageing population. Although some data suggest that spironolactone might improve outcomes in these patients, no therapy has conclusively shown a significant effect. Hopefully, future studies will address these unmet needs for patients with heart failure. Admissions for acute heart failure continue to increase but, to date, no new therapies have improved clinical outcomes.

Current rare indications and future directions for implantable loop recorders

The scope of application for implantable loop recorders has shifted away from the evaluation of unclear palpitations and syncope episodes to more complex conditions. This article focuses on rare indications of growing importance such as rhythm monitoring after ablation of atrial fibrillation or after cryptogenic stroke. Furthermore, forthcoming applications in various clinical settings are described, e. g., arrhythmia detection after myocardial infarction, after catheter-based valve interventions, in heart failure, and in cardiomyopathies. Enhancement of the capabilities of implantable loop recorders could broaden their fields of use.

[Current impact of cardiac implantable electronic devices]

Sudden cardiac death and chronic heart failure are among the main contributors to persisting high mortality rates in Germany. In addition to removal of causal factors and guideline-conform pharmacological therapy, therapy with cardiac implantable electronic devices (CIED) is of undisputed importance. Subcutaneous defibrillators have the advantage that they do not have intracardiac electrodes but still have the same efficacy and safety. For patients with a wide QRS complex and reduced ejection fraction, cardiac resynchronization has led to a reduction of morbidity and mortality. For patients with a normal QRS complex, cardiac contractility modulation had been shown to improve the quality of life, exercise capacity and left ventricular function. As a procedure for autonomic modulation in patients with reduced cardiac strength, the data for baroreceptor stimulation are the most convincing.

Long-term spinal cord stimulation modifies canine intrinsic cardiac neuronal properties and ganglionic transmission during high-frequency repetitive activation

Long‐term spinal cord stimulation (SCS) applied to cranial thoracic SC segments exerts antiarrhythmic and cardioprotective actions in the canine heart in situ. We hypothesized that remodeling of intrinsic cardiac neuronal and synaptic properties occur in canines subjected to long‐term SCS, specifically that synaptic efficacy may be preferentially facilitated at high presynaptic nerve stimulation frequencies. Animals subjected to continuous SCS for 5–8 weeks (long‐term SCS: n = 17) or for 1 h (acute SCS: n = 4) were compared with corresponding control animals (long‐term: n = 15, acute: n = 4). At termination, animals were anesthetized, the heart was excised and neurones from the right atrial ganglionated plexus were identified and studied in vitro using standard intracellular microelectrode technique. Main findings were as follows: (1) a significant reduction in whole cell membrane input resistance and acceleration of the course of AHP decay identified among phasic neurones from long‐term SCS compared with controls, (2) significantly more robust synaptic transmission to rundown in long‐term SCS during high‐frequency (10–40 Hz) presynaptic nerve stimulation while recording from either phasic or accommodating postsynaptic neurones; this was associated with significantly greater posttrain excitatory postsynaptic potential (EPSP) numbers in long‐term SCS than control, and (3) synaptic efficacy was significantly decreased by atropine in both groups. Such changes did not occur in acute SCS. In conclusion, modification of intrinsic cardiac neuronal properties and facilitation of synaptic transmission at high stimulation frequency in long‐term SCS could improve physiologically modulated vagal inputs to the heart.

Post-extrasystolic Potentiation: Link between Ca(2+) Homeostasis and Heart Failure?

Post-extrasystolic potentiation (PESP) describes the phenomenon of increased contractility of the beat following an extrasystole and has been attributed to changes in Ca(2+) homeostasis. While this effect has long been regarded to be a normal physiological phenomenon, a number of reports describe an enhanced potentiation of the post-extrasystolic beat in heart failure patients. The exact mechanism of this increased PESP is unknown, but disruption of normal Ca(2+) handling in heart failure may be the underlying cause. The use of PESP as a prognostic marker or therapeutic intervention have recently regained new attention, however, the value of the application of PESP in the clinic is still under debate. In this review, the mechanism of PESP with regard to Ca(2+) in the normal and failing heart will be discussed and the possible diagnostic and therapeutic role of this phenomenon will be explored.

New Management Strategies in Heart Failure

Despite >100 clinical trials, only 2 new drugs had been approved by the US Food and Drug Administration for the treatment of chronic heart failure in more than a decade: the aldosterone antagonist eplerenone in 2003 and a fixed dose combination of hydralazine-isosorbide dinitrate in 2005. In contrast, 2015 has witnessed the Food and Drug Administration approval of 2 new drugs, both for the treatment of chronic heart failure with reduced ejection fraction: ivabradine and another combination drug, sacubitril/valsartan or LCZ696. Seemingly overnight, a range of therapeutic possibilities, evoking new physiological mechanisms, promise great hope for a disease that often carries a prognosis worse than many forms of cancer. Importantly, the newly available therapies represent a culmination of basic and translational research that actually spans many decades. This review will summarize newer drugs currently being used in the treatment of heart failure, as well as newer strategies increasingly explored for their utility during the stages of the heart failure syndrome.

Vagus nerve stimulation: state of the art of stimulation and recording strategies to address autonomic function neuromodulation

OBJECTIVE

Neural signals along the vagus nerve (VN) drive many somatic and autonomic functions. The clinical interest of VN stimulation (VNS) is thus potentially huge and has already been demonstrated in epilepsy. However, side effects are often elicited, in addition to the targeted neuromodulation.

APPROACH

This review examines the state of the art of VNS applied to two emerging modulations of autonomic function: heart failure and obesity, especially morbid obesity.

MAIN RESULTS

We report that VNS may benefit from improved stimulation delivery using very advanced technologies. However, most of the results from fundamental animal studies still need to be demonstrated in humans.

Autonomic Modulation in Heart Failure: Ready for Prime Time?

It has been known for many decades that multiple abnormalities of the autonomic nervous system (ANS) are present in heart failure (HF). Moreover, many of the effective therapies currently used to treat HF have either direct or indirect effects on the ANS. While therapies that block over-activity of the sympathetic nervous system are now standard of care, much less well studied are therapies aimed at augmenting the parasympathetic nervous system. This review will cover recent and ongoing investigations targeting modulation of the ANS, especially highlighting new and ongoing studies directed toward augmenting parasympathetic mechanisms.

Innervation of the heart: An invisible grid within a black box

Autonomic control of cardiovascular function is mediated by a complex interplay between central, peripheral, and innate cardiac components. This interplay is what mediates the normal cardiovascular response to physiologic and pathologic stressors, including blood pressure, cardiac contractile function, and arrhythmias. However, in order to understand how modern therapies directly affecting autonomic function may be harnessed to treat various cardiovascular disease states requires an intimate understanding of anatomic and physiologic features of the innervation of the heart. Thus, in this review, we focus on defining features of the central, peripheral, and cardiac components of cardiac innervation, how each component may contribute to dysregulation of normal cardiac function in various disease states, and how modulation of these components may offer therapeutic options for these diseases.

[Chronic cervical vagal stimulation. Mechanisms of action and clinical relevance for heart failure]

Increased sympathetic nerve activity and reduced vagal activity are associated with increased mortality in patients after myocardial infarction and patients with chronic heart failure; furthermore, vagal withdrawal has been documented to precede acute decompensation. Experimental studies have indicated that increased parasympathetic activity by means of vagal stimulation may reduce mortality in animal models of postinfarction sudden cardiac death and of chronic heart failure. First clinical results have demonstrated that chronic vagus nerve stimulation in heart failure patients with severe systolic dysfunction appears to be safe and tolerable and may improve the quality of life and left ventricular (LV) function. Vagus nerve stimulation gives rise to these potential clinical benefits by multiple mechanisms of action, including reduced heart rate, restoration of heart rate variability and baroreflex sensitivity, suppression of proinflammatory cytokines and antiarrhythmic effects. First clinical results suggest that vagal nerve stimulation is safe and tolerable and could lead to a marked clinical improvement but discrepancies in the findings due to different study designs warrant further discussion.

Heart Failure With Reduced Ejection Fraction And A Narrow QRS Complex: Combination Of A Subcutaneous Defibrillator With Cardiac Contractility Modulation

Cardiac contractility modulation (CCM) is a relatively new electrical therapy for heart failure patients with reduced ejection fraction. The majority of patients eligible for CCM will also need an implantable cardioverter-defibrillator (ICD). To-date, three pacing electrodes are mandatory for CCM therapy because the current CCM signal delivery algorithm requires sequential intracardiac sensing of a p-wave, followed by appropriately timed ventricular activation by the two ventricular septal leads. As there is no device combining CCM with ICD functions, most CCM patients will need multiple intracardiac electrodes, which increase the cumulative risk for complications such as systemic infections, thrombosis of central venous lines, insulation failures or lead fractures. The long-term complications associated with trans-venous ICD leads have led to the development of a totally subcutaneous implantable cardioverter-defibrillator (S-ICD). In this essay the two technologies CCM and S-ICD are reviewed. Additionally, we present their successful combination on the basis of a case report on the first patient receiving both devices.

[Implantable hemodynamic monitoring devices]

Heart failure is one of the most frequent diagnoses in hospital admissions in Germany. In the majority of these admissions acute decompensation of an already existing chronic heart failure is responsible. New mostly wireless and remote strategies for monitoring, titration, adaptation and optimization are the focus for improvement of the treatment of heart failure patients and the poor prognosis. The implantation of hemodynamic monitoring devices follows the hypothesis that significant changes in hemodynamic parameters occur before the occurrence of acute decompensation requiring readmission. Three different hemodynamic monitoring devices have so far been investigated in clinical trials employing right ventricular pressure, left atrial pressure and pulmonary artery pressure monitoring. Only one of these systems, the CardioMENS™ HF monitoring system, demonstrated a significant reduction of hospitalization due to heart failure over 6 months in the CHAMPION trial. The systematic adaptation of medication in the CHAMPION trial significantly differed from the usual care of the control arm over 6 months. This direct day to day management of diuretics is currently under intensive investigation; however, further studies demonstrating a positive effect on mortality are needed before translation of this approach into guidelines. Without this evidence a further implementation of pressure monitoring into currently used devices and justification of the substantial technical and personnel demands are not warranted.

Remodelling of cardiac sympathetic re-innervation with thoracic spinal cord stimulation improves left ventricular function in a porcine model of heart failure

AIMS

Thoracic spinal cord stimulation (SCS) has been shown to improve left ventricular ejection fraction (LVEF) in heart failure (HF). Nevertheless, the optimal duration (intermittent vs. continuous) of stimulation and the mechanisms of action remain unclear.

METHODS AND RESULTS

We performed chronic thoracic SCS at the level of T1-T3 (50 Hz, pulse width 0.2 ms) in 30 adult pigs with HF induced by myocardial infarction and rapid ventricular pacing for 4 weeks. All the animals were treated with daily oral metoprolol succinate (25 mg) plus ramipril (2.5 mg), and randomized to a control group (n = 10), intermittent SCS (4 h ×3, n = 10) or continuous SCS (24 h, n = 10) for 10 weeks. Serial measurements of LVEF and +dP/dt and serum levels of norepinephrine and B-type natriuretic peptide (BNP) were measured. After sacrifice, immunohistological studies of myocardial sympathetic and parasympathetic nerve sprouting and innervation were performed. Echocardiogram revealed a significant increase in LVEF and +dP/dt at 10 weeks in both the intermittent and continuous SCS group compared with controls (P < 0.05). In both SCS groups, there was diffuse sympathetic nerve sprouting over the infarct, peri-infarct, and normal regions compared with only the peri-infarct and infarct regions in the control group. In addition, sympathetic innervation at the peri-infarct and infarct regions was increased following SCS, but decreased in the control group. Myocardium norepinephrine spillover and serum BNP at 10 weeks was significantly decreased only in the continuous SCS group (P < 0.05).

CONCLUSIONS

In a porcine model of HF, SCS induces significant remodelling of cardiac sympathetic innervation over the peri-infarct and infarct regions and is associated with improved LV function and reduced myocardial norepinephrine spillover.

Interventional and device-based autonomic modulation in heart failure

"Heart failure is an increasingly prevalent disease with high mortality and public health burden. It is associated with autonomic imbalance characterized by sympathetic hyperactivity and parasympathetic hypoactivity. Evolving novel interventional and device-based therapies have sought to restore autonomic balance by neuromodulation. Results of preclinical animal studies and early clinical trials have demonstrated the safety and efficacy of these therapies in heart failure. This article discusses specific neuromodulatory treatment modalities individually-spinal cord stimulation, vagus nerve stimulation, baroreceptor activation therapy, and renal sympathetic nerve denervation."

Efficacy and survival in patients with cardiac contractility modulation: long-term single center experience in 81 patients

AIMS

To analyze long-term efficacy and survival in patients with chronic heart failure treated with cardiac contractility modulation.

METHODS

81 patients implanted with a CCM device between 2004 and 2012 were included in this retrospective analysis. Changes in NYHA class, ejection fraction (EF), Minnesota Living with Heart Failure Questionnaire, NT-proBNP and peak VO₂ were analyzed during a mean follow up of 34.2 ± 28 months (6-123 months). Observed mortality rate was compared with that predicted by the MAGGIC Score.

RESULTS

Patients were 61 ± 12 years old with EF 23 ± 7%. Heart failure was due to ischemic (n=48, 59.3%) or idiopathic dilated (n=33, 40.7%) cardiomyopathy. EF increased from 23.1 ± 7.9 to 29.4 ± 8.6% (p<0.05), mean NT-proBNP decreased from 4395 ± 3818 to 2762 ± 3490 ng/l (p<0.05) and mean peak VO2 increased from 13.9 ± 3.3 to 14.6 ± 3.5 ml/kg/min (p=0.1). The overall clinical responder rate (at least 1 class improvement of NYHA within 6 months or last follow-up) was 74.1%. 21 (25.9%) patients died during follow up, 11 (52.4%) due to cardiac conditions and 10 (47.6%) due to non-cardiac conditions. Mortality rates at 1 and 3 years were 5.2% and 29.5% compared to mortality rates estimated from the MAGGIC risk score of 18.4% (p<0.001) and 40% (p=ns), respectively. Log-Rank analysis of all events through 3 years of follow-up, however, was significantly less than predicted (p=0.022).

CONCLUSIONS

CCM therapy improved quality of life, exercise capacity, NYHA class, EF and NT-proBNP levels during long-term follow up. Mortality rates appeared to be lower than estimated from the MAGGIC score.

Long term impact of cardiac contractility modulation on QRS duration

BACKGROUND AND PURPOSE

Cardiac contractility modulation (CCM) is an implantable device treatment for heart failure with reduced ejection fraction. CCM therapy improves patient functional status but its effect on intra-ventricular conduction remains unknown.

METHODS

70 patients treated with CCM between 12/2002 and 5/2013 had 12-vector-ECG recordings made at baseline and final follow-up visits. QRS complex duration was measured at each time point.

RESULTS

Mean follow-up was 2.8 years. Mean QRS duration was unchanged from baseline (112.0 ms) to last follow up (112.9 ms, p=n.s.). These results are strikingly different from comparative published data of several studies with heart failure patients without CCM, consistently indicating an increase in QRS duration (6.0-23.4 ms) over a similar time period.

CONCLUSIONS

CCM prevents chronic ventricular depolarization delay that occurs in heart failure and that is associated with poorer outcomes. This supports the safety of long-term CCM therapy and suggests a possible long-term benefit in maintaining QRS duration.