Epicardial versus Transvenous Left Ventricular Lead Placement in Patients Receiving Cardiac Resynchronization Therapy: Results from a Randomized Prospective Study

Assessing cardiac resynchronization therapy response in heart failure patients: a comparative analysis of efficacy and outcomes between transvenous and epicardial leads

Cardiac resynchronization therapy (CRT) is an effective treatment for selected heart failure (HF) patients. Although transvenous implantation is the standard method, it is not feasible in some patients, so the epicardial lead emerges as an alternative. We aim to compare CRT response, procedure-related complications, and the occurrence of clinical outcomes between patients with transvenous and epicardial leads. In a single-center retrospective study, we enrolled consecutive HF patients submitted to CRT implantation with a defibrillator between 2013 and 2022. Clinical response was defined as an improvement of at least one of the New York Heart Association classes with no occurrence of cardiovascular death or HF hospitalization in the first year of follow-up. Echocardiographic response was attained with an increase in left ventricular ejection fraction 10% or a reduction of left ventricular end-diastolic volume >15% at 6-12 months after CRT implantation. Major adverse cardiovascular events (MACE) (cardiovascular mortality and HF hospitalization) and all-cause mortality were evaluated. From a total of 149 patients, 38% (n=57) received an epicardial lead. Clinical (63% versus 60%, p=0.679) and echocardiographic (63% versus 60%, p=0.679) responses were similar between the transvenous and epicardial groups. Patients in the transvenous group had a shorter hospital stay (2 versus 7 days, p<0.001). Procedure-related complications were comparable between groups (24% versus 28%, p=0.572), but left ventricular lead-related complications were more frequent in the transvenous group (14% versus 2%). During a median follow-up of 4.7 years, the rate of MACE was 30% (n=44), with no differences in both groups (p=0.591), neither regarding HF hospitalization (p=0.917) nor cardiovascular mortality (p=0.060). Nevertheless, the epicardial group had a higher rate of all-cause mortality (35% versus 20%, p=0.005), the majority occurring during long-term follow-up (>12 months), with no deaths in the postoperative period. Considering the comparable rates of CRT response, procedure-related complications, and MACE between groups, we conclude that epicardial lead is a feasible alternative for CRT when transvenous lead implantation is not possible. The occurrence of a higher number of all-cause deaths in epicardial patients in the long-term follow-up was mainly due to infectious complications (unrelated to the lead) and the progression of oncological/chronic diseases.

Video-assisted thoracoscopic epicardial pacing: A contemporary overview

Video-assisted thoracoscopic surgery (VATS) has revolutionized the approach and management of pulmonary and cardiac diseases, and its applications have significantly expanded in the last two decades. Beyond its established role in thoracic procedures, VATS has also emerged as a valuable technique for various electrophysiological procedures, including pacemaker implantations, ablation procedures, and left atrial appendage exclusion. This paper presents a thorough review of the existing literature on pacing procedures performed using a VATS approach. By analyzing and synthesizing the available studies, we aim to provide an in-depth understanding of the current knowledge and advancements in VATS-based pacing procedures. A key focus of this review is the detailed description of implantation techniques via a VATS approach.

Long-Term Performance of Epicardial versus Transvenous Left Ventricular Leads for Cardiac Resynchronization Therapy

Aims: to study the technical performance of epicardial left ventricular (LV) leads placed via video assisted thoracic surgery (VATS), compared to transvenously placed leads for cardiac resynchronization therapy (CRT). Methods: From 2001 until 2013, a total of 644 lead placement procedures were performed for CRT. In the case of unsuccessful transvenous LV lead placement, the patient received an epicardial LV lead. Study groups consist of 578 patients with a transvenous LV lead and 66 with an epicardial LV lead. The primary endpoint was LV-lead failure necessitating a replacement or deactivation. The secondary endpoint was energy consumption. Results: The mean follow up was 5.9 years (epicardial: 5.5 ± 3.1, transvenous: 5.9 ± 3.5). Transvenous leads failed significantly more frequently than epicardial leads with a total of 66 (11%) in the transvenous leads group vs. 2 (3%) in the epicardial lead group (p = 0.037). Lead energy consumption was not significantly different between groups. Conclusions: Epicardial lead placement is feasible, safe and shows excellent long-term performance compared to transvenous leads. Epicardial lead placement should be considered when primary transvenous lead placement fails or as a primary lead placement strategy in challenging cases.

Etiology and device therapy in complete atrioventricular block in pediatric and young adult population: Contemporary review and new perspectives

Complete atrioventricular block (CAVB) is a total dissociation between the atrial and ventricular activity, in the absence of atrioventricular conduction. Several diseases may result in CAVB in the pediatric and young-adult population. Permanent right ventricular (RV) pacing is required in permanent CAVB, when the cause is neither transient nor reversible. Continuous RV apical pacing has been associated with unfavorable outcomes in several studies due to the associated ventricular dyssynchrony. This study aims to summarize the current literature regarding CAVB in the pediatric and young adult population and to explore future treatment perspectives.

Caudocranial transseptal approach for placement of endocardial left ventricular leads

Cardiac resynchronization therapy (CRT) is associated with improvement in the quality of life, hospitalization rates, and mortality in patients with left ventricular dysfunction and evidence of the right ventricle-left ventricle (RV-LV) desynchrony. Implant failure rates and patient outcomes have improved with the advent of quadripolar leads, yet alternatives to traditional coronary sinus (CS) LV lead placement is sought for in a subset of advanced heart failure patients with difficult CS anatomy, phrenic nerve stimulation or in nonresponders. Endocardial left ventricular pacing (EnLVP) in chronically anticoagulated patients has been reported as an alternative using different approaches, techniques, and tools with acceptable short and long term adverse events. We present a case of successful EnLVP achieved for CRT using standard techniques and commonly available tools in a patient on chronic direct oral anticoagulation with recurrent heart failure admissions who failed traditional epicardial LV pacing.

Epicardial left ventricular lead implantation in cardiac resynchronization therapy patients via a video-assisted thoracoscopic technique: Long-term outcome

BACKGROUND

Epicardial placement of the left ventricular (LV) lead via a video-assisted thoracoscopic (VAT) approach is an alternative to the standard transvenous technique.

HYPOTHESIS

Long-term safety and efficacy of VAT and transvenous LV lead implantation are comparable. To test it, we reviewed our experience and we compared the outcomes of patients who underwent implantation with the two techniques.

METHODS

The VAT procedure is performed under general anesthesia, with oro-tracheal intubation and right-sided ventilation, and requires two 5 mm and one 15 mm thoracoscopic ports. After pericardiotomy at the spot of the epicardial target area, pacing measurements are taken and a spiral screw electrode is anchored at the final pacing site. The electrode is then tunneled to the pectoral pocket and connected to the device.

RESULTS

105 patients were referred to our center for epicardial LV lead implantation. After pre-operative assessment, 5 patients were excluded because of concomitant conditions precluding surgery. The remaining 100 underwent the procedure. LV lead implantation was successful in all patients (median pacing threshold 0.8 ± 0.5 V, no phrenic nerve stimulation) and cardiac resynchronization therapy was established in all but one patient. The median procedure time was 75 min. During a median follow-up of 24 months, there were no differences in terms of death, cardiovascular hospitalizations or device-related complications vs the group of 100 patients who had undergone transvenous implantation. Patients of both groups displayed similar improvements in terms of ventricular reverse remodeling and functional status.

CONCLUSIONS

Our VAT approach proved safe and effective, and is a viable alternative in the case of failed transvenous LV implantation.

The quantitative assessment of epicardial fat distribution on human hearts: Implications for epicardial electrophysiology

Epicardial electrophysiological procedures rely on dependable interfacing with the myocardial tissue. For example, epicardial pacing systems must generate sustainable chronic pacing capture, while epicardial ablations must effectively deliver energy to the target hyper-excitable myocytes. The human heart has a significant adipose layer which may impede epicardial procedures. The objective of this study was to quantitatively assess the relative location of epicardial adipose on the human heart, to define locations where epicardial therapies might be performed successfully. We studied perfusion-fixed human hearts (n = 105) in multiple isolated planes including: left ventricular margin, diaphragmatic surface, and anterior right ventricle. Relative adipose distribution was quantitatively assessed via planar images, using a custom-generated image analysis algorithm. In these specimens, 76.7 ± 13.8% of the left ventricular margin, 72.7 ± 11.3% of the diaphragmatic surface, and 92.1 ± 8.7% of the anterior right margin were covered with superficial epicardial adipose layers. Percent adipose coverage significantly increased with age (P < 0.001) and history of coronary artery disease (P < 0.05). No significant relationships were identified between relative percent adipose coverage and gender, body weight or height, BMI, history of hypertension, and/or history of congestive heart failure. Additionally, we describe two-dimensional probability distributions of epicardial adipose coverage for each of the three analysis planes. In this study, we detail the quantitative assessment and probabilistic mapping of the distribution of superficial epicardial adipose on the adult human heart. These findings have implications relative to performing epicardial procedures and/or designing procedures or tools to successfully perform such treatments. Clin. Anat. 31:661-666, 2018. © 2018 Wiley Periodicals, Inc.

Epicardial left ventricular leads via minimally invasive technique: a role of steroid eluting leads

Background

We retrospectively assessed two types of sutureless screw-in left ventricular (LV) leads (steroid eluting vs. non-steroid eluting) in cardiac resynchronization therapy (CRT) implantation with regards to their electrical performance.

Methods

Between March 2008 and May 2014 an epicardial LV lead was implanted in 32 patients after failed transvenous LV lead placement using a left-sided lateral minithoracotomy or video-assisted thoracoscopy (mean age 64 ± 9 years). Patients were divided into two groups according to the type of implanted lead. Steroid eluting (SE) group: 21 patients (Myodex™ 1084 T; St. Jude Medical) and non-steroid eluting (NSE) group: 11 patients (MyoPore® 511,212; Greatbatch Medical).

Results

All epicardial leads could be placed successfully, without any intraoperative complications or mortality. With regard to the implanted lead following results were observed: sensing (mV): SE 8.8 ± 6.1 vs. NSE 10.1 ± 5.3 (p = 0.380); pacing threshold (V@0.5 ms): SE 1.0 ± 0.5 vs. NSE 0.9 ± 0.5 (p = 0.668); impedance (ohms): SE 687 ± 236 vs. NSE 790 ± 331 (p = 0.162). At the follow-up (2.6 ± 1.9 years) the following results were seen: sensing (mV): SE 8.7 ± 5.0 vs. NSE 11.2 ± 6.6 (p = 0.241), pacing threshold (V@0.5 ms): SE 1.4 ± 0.5 vs. NSE 1.0 ± 0.3 (p = 0.035), impedance (ohms): SE 381 ± 95 vs. NSE 434 ± 88 (p = 0.129).

Conclusions

Based on the results no strong differences have been found between the both types of epicardial LV leads (steroid eluting vs. non-steroid eluting) in CRT implantation in short- and midterm.

Dual-site right ventricular pacing in patients undergoing cardiac resynchronization therapy: Results of a multicenter propensity-matched analysis

BACKGROUND

Dual-site right ventricular pacing (Dual RV) has been proposed as an alternative for patients with heart failure undergoing cardiac resynchronization therapy (CRT) with a failure to deliver a coronary sinus (CS) lead. Only short-term hemodynamic and echocardiographic results of Dual RV are available. We aimed to assess the long-term results of Dual RV and its impact on survival.

METHODS

Multicenter retrospective assessment of all CRT implants during a 12-year period. Patients with failed CS lead implantation, treated with Dual RV, were followed and assessed for the primary endpoint of all-cause mortality and/or heart transplant. A control group was obtained from contemporary patients using propensity matching for all available baseline variables.

RESULTS

Ninety-three patients were implanted with Dual RV devices and compared with 93 matched controls. During a median of 1,273 days (interquartile range 557-2,218), intention-to-treat analysis showed that all-cause mortality and/or heart transplant was higher in the Dual RV group (adjusted hazard ratio [HR] = 1.66, 95% confidence interval [CI] 1.12-2.47, P = 0.012). As-treated analysis yielded similar results (HR = 1.97, 95% CI 1.31-2.96, P = 0.001). Cardiac device-related infections occurred seven times more frequently in the Dual RV site group (HR = 7.60, 95% CI 1.51-38.33, P = 0.014). Among Dual RV nonresponders, four had their apical leads switched off, five required an epicardial LV lead insertion, a transseptal LV lead was implanted in two, and in nine patients, after reviewing the CS venogram, a new CS lead insertion was successfully attempted.

CONCLUSION

Dual RV pacing is associated with worse clinical outcomes and higher complication rates than conventional CRT.

Surgical placement of left ventricular lead for cardiac resynchronisation therapy after failure of percutaneous attempt

Objective

Cardiac resynchronisation therapy has been shown to be an effective treatment to improve functional status and prolong survival of patients in advanced chronic heart failure. This study assessed the surgical outcomes of left anterior mini-thoracotomy for the implantation of left ventricular epicardial pacing leads in cardiac resynchronisation therapy.

Methods

Our study consisted of 30 consecutive patients who underwent cardiac resynchronisation therapy with a left thoracotomy between November 2010 and April 2012 in our clinic. Postoperative follow up included the assessment of New York Heart Association (NYHA) functional class, electrocardiography and echocardiography.

Results

There were 22 male and eight female patients with a mean age of 68 ± 5.04 years. All patients were in NYHA class III or IV. Pre-procedure mean left ventricular ejection fraction was 28.1 ± 4.5% and post-procedural ejection fraction improved to 31.7 ± 5.1%. The pre-operative QRS duration changed from 171.7 ± 10.8 to 156.2 ± 4.4 ms after the operation. Also there was a significant reduction in left ventricular end-diastolic dimension from 6.98 ± 0.8 to 6.72 ± 0.8 mm (p < 0 .05), but no change in left ventricular end-systolic dimension and severity of mitral regurgitation. All patients had successful surgical left ventricular lead placement. There was no procedure-related mortality. The mean follow-up time was 40.4 months.

Conclusion

Surgical epicardial left ventricular lead placement procedure is a safe and effective technique in patients with a failed percutaneous attempt.

Long-Term Follow-Up of Isolated Epicardial Left Ventricular Lead Implant Using a Minithoracotomy Approach for Cardiac Resynchronization Therapy

BACKGROUND

Transvenous left ventricular (LV) lead placement for cardiac resynchronization therapy is unsuccessful in 5-10% of reported cases. These patients may benefit from isolated surgical placement of an epicardial LV lead via minithoracotomy approach.

AIM

To evaluate the success of this approach at long-term follow-up.

METHODS

Retrospective evaluation of all consecutive patients undergoing isolated epicardial LV lead placement after failed transvenous attempt over a 6-year period. Data collected on baseline parameters, procedural details, and outcome at follow-up (hospital stay, complications, mortality, and clinical response).

RESULTS

Forty-two patients underwent epicardial lead implant. Five died within 1 year (11.9%): two (4.8%) died within 30-days post op (one from intraoperative hemorrhage, the other from multiple organ failure); 39 (95.1%) were admitted to the high dependency unit and transferred to the ward <24 hours. Median hospital stay was 3.4 ± 1.9 days. The overall complication rate was 17.5% (n = 7): 15.0% (n = 6) short term and 2.5% (n = 1) long term; these included three (7.5%) LV noncapture events all treated with reprogramming. There were two (5.0%) wound infections requiring oral antibiotics and two (5.0%) device infections requiring intravenous antibiotics (one had device resiting, the other developed septic shock requiring intensive care admission). Assessment of clinical response was possible in 34 (81.0%) at follow-up: 21 (61.8%) were responders and 13 (28.2%) nonresponders with no significant differences between these groups; no clinical predictors of response were identified.

CONCLUSION

Isolated epicardial LV lead implant using minithoracotomy is relatively safe and effective at successful LV pacing. Response rate and postoperative recovery at long-term follow-up are reasonable in these high-risk patients.

Alternative to left ventricular lead implantation through the coronary sinus: 1-year experience with a minimally invasive and robotically guided approach

AIMS

Left ventricular (LV) lead implantation through the coronary sinus (CS) can be limited and sometimes not possible-alternative approaches are needed. Minimally invasive, robotically guided LV lead implantation has major advantages, but there are little published data about the short- and long-term follow-ups, in terms of feasibility, safety, electrical performance, and impact on clinical outcome.

METHODS AND RESULTS

A total of 21 heart failure patients underwent robotically guided LV lead implantation using the Da Vinci Robotic System. Indications were failed implant with conventional approach through the CS (n = 16) and non-response to conventional cardiac resynchronization therapy (n = 5). During the procedure, the entire LV free wall was exposed through 3 transthoracic ports (10 mm diameter each) allowing ample choice of stimulation site and the ability to implant 2 LV leads via a Y connector. Patients were prospectively followed up for 1 year. The two LV leads were successfully implanted in all patients. No peri-procedural complications were observed. After a mean stay in the intensive care unit of 1.2 ± 4 days, the 21 patients were hospitalized in the EP department for 6.7 ± 2.9 days. Acute LV thresholds were excellent (1.0 V ± 0.6/0.4 ms) and stayed stable at 1-year follow-up (1.5 V ± 0.6/0.4 ms, P = 0.21). Four patients demonstrated an increased threshold (>2 V/0.4 ms). There was no phrenic nerve stimulation. After 12 months, in the failed implant group, 69% of the patients were echocardiographic and clinical responders.

CONCLUSION

The robotic approach was feasible, safe, and minimally invasive. Accordingly, robotically guided LV lead implantation seems to offer a new alternative when conventional approaches are not suitable.

Optimizing CRT - Do We Need More Leads and Delivery Methods

Cardiac resynchronization therapy (CRT) is an established therapeutic option in symptomatic heart failure with reduced ejection fraction and evidence of left ventricular (LV) conduction delay (QRS width ≥120 ms), especially when typical left bundle branch block is present. The rationale behind CRT is restoration of aberrant LV electrical activation. As there is considerable heterogeneity of the LV electrical activation pattern among CRT candidates, an individualized approach with targeting of the LV lead in the region of latest electrical activation while avoiding scar tissue may enhance CRT response. Echocardiography, electro anatomic mapping, and cardiac magnetic resonance imaging with late gadolinium enhancement are helpful to guide such targeted LV lead placement. However, an important limitation remains the anatomy of the coronary sinus, which often does not allow concordant LV lead placement in the optimal region. Epicardial LV lead placement through minimal invasive surgery or endocardial LV lead placement through transseptal punction may overcome this limitation, obviously with an increased complication risk. Furthermore, recent pacing algorithms suggest superiority of LV-only versus biventricular pacing in patients with preserved atrio ventricular (AV) conduction and a typical LBBB pattern. Finally, pacing from only one LV site might not overcome the wide electrical dispersion often seen in patients with LV conduction delays. Therefore, multisite pacing has gained significant interest to improve CRT response. The use of multiple LV leads may potentially lead to more favorable reverse remodeling, improved functional capacity and quality of life in CRT candidates, but adverse events and a shorter battery span are more frequent because of the extra lead. The use of one multipolar LV lead increases the number of pacing configurations within the same coronary sinus side branch (within small distances from each other) without the use of an additional lead. Small observational studies suggest that more effective resynchronization can be achieved with this approach. Finally, there are many reasons for non effective CRT delivery in carefully selected patients with an adequately implanted device. Multidisciplinary, post implantation care inside a dedicated CRT clinic ensures optimal CRT delivery, improves response rate and should be considered standard of care.

Prophylactic epicardial left ventricular lead implantation for biventricular pacing during operations

BACKGROUND

Surgical epicardial left ventricular (LV) lead implantation for biventricular pacing has advantages over the transvenous approach in cardiac surgical patients. We investigated the benefit of concomitant prophylactic LV lead implantation during open heart operations and subsequent lead performance after patients with impaired LV function receive a biventricular device.

METHODS

Retrospective data of 4,844 patients undergoing cardiac operations through a sternotomy between January 2001 and December 2011 were analyzed. Of these, 380 patients (7.8%) had severe impairment of LV function (contrast left ventriculogram showing grade 4 estimated ejection fraction or echocardiogram showing LV ejection fraction<0.30). LV lead implantation was performed in patients in whom recovery of LV function was unlikely. Lead performance data were collected at follow-up.

RESULTS

LV lead implantation occurred in 95 patients (25%), and 29 (30.5%) subsequently received a biventricular device. Of patients with impaired LV function, more patients with prophylactic LV leads underwent biventricular implant than those without LV leads (30.5% vs 1.1%, p<0.0001). The median interval from LV lead implantation to connection to a biventricular device was 30 days (interquartile range, 5.5 to 145 days). At a median follow-up of 437.5 days (interquartile range, 13.8 to 1198 days), the mean pacing threshold (1.25±0.46 vs 1.58±0.66 volts, p=0.069) and impedance (383.81±70.33 vs 448.6±200.1 Ohms, p=0.168) remained stable compared with time of biventricular device connection.

CONCLUSIONS

A significant proportion of patients with poor LV function undergoing cardiac operations may benefit from concomitant LV lead implantation. Subsequent lead performance appears satisfactory. Epicardial LV lead placement is easily accomplished during open heart operations and should be considered before the operation.

Patent foramen ovale. Correct route for implantation of a biventricular permanent pacemaker?

INTRODUCTION

Intentional or unintentional placement of a pacemaker lead into the left ventricle is an uncommon clinical entity that is associated with a high risk for systemic embolization and enormous difficulties in case of explantation. Unintentional implantation through a patent foramen ovale via the mitral valve is the usual pathway for this malposition.

METHODS

We report a case where a pacemaker lead was placed intentionally into the left ventricle via a patent foramen ovale for biventricular pacing for resynchronization therapy. Later, the patient developed life-threatening pacemaker lead-associated endocarditis with sepsis. Emergency open heart surgery for lead removal was necessary in the form of a reoperation after bypass graft surgery a number of years earlier.

CONCLUSION

Although it is technically feasible to implant the pacemaker lead into the left ventricle via a patent foramen ovale, we consider this option to be obsolete for use with a biventricular pacemaker, due to the multitude of risks, which can, in part, be life-threatening for the patient.

[Cardiac resynchronization therapy: preoperative screening. How can we reliably predict response to CRT?]

Cardiac resynchronization therapy (CRT) is an established therapy for patients with advanced heart failure, depressed left ventricular function, and wide QRS complex. However, about 30 to 45% of patients do not respond to CRT. Assuming that the main therapeutic action of CRT is the correction of dyssynchronous myocardial contraction, a plethora of echocardiographic dyssynchrony parameters have been proposed to improve the prediction of response to CRT. However, one multicenter study has recently questioned the utility of any of these indexes. This review delineates the various causes of non-response to CRT, explains the different levels and mechanisms of dyssynchrony and gives a critical overview of currently available echocardiographic techniques for assessment of dyssynchrony. Based upon a discussion of the evidence coming from randomized multicenter studies and against the background of national and international cardiac societies' guideline recommendations on CRT, a rational basis for the evaluation of patients for CRT is proposed.

Cardiac resynchronization therapy in the cardiorenal syndrome

The cardiorenal syndrome (CRS) is a complex clinical syndrome in which dysfunction of either the heart or the kidneys affects the functioning of the other organ system. Many therapies used in heart failure have further detrimental effects on renal function. Cardiac resynchronization therapy (CRT) is a relatively new form of device therapy that reduces morbidity and mortality in patients with heart failure. This review will discuss the effects of CRT on renal function in patients with CRS, the impact of baseline renal function on response to CRT, and potential risks associated with CRT in this unique population.

Event-free survival following CRT with surgically implanted LV leads versus standard transvenous approach

BACKGROUND

While surgical epicardial lead placement is performed in a subset of cardiac resynchronization therapy patients, data comparing survival following surgical versus transvenous lead placement are limited. We hypothesized that surgical procedures would be associated with increased mortality risk.

METHODS

Long-term event-free survival was assessed for 480 consecutive patients undergoing surgical (48) or percutaneous (432) left ventricle (LV) lead placement at our institution from January 2000 to September 2008.

RESULTS

Baseline clinical and demographic characteristics were similar between groups. While there was no statistically significant difference in overall event-free survival (P = 0.13), when analysis was restricted to surgical patients with isolated surgical lead placement (n = 28), event-free survival was significantly lower in surgical patients (P = 0.015). There appeared to be an early risk (first approximately 3 months postimplantation) with surgical lead placement, primarily in LV lead-only patients. Event rates were significantly higher in LV lead-only surgical patients than in transvenous patients in the first 3 months (P = 0.006). In proportional hazards analysis comparing isolated surgical LV lead placement to transvenous lead placement, adjusted hazard ratios were 1.8 ([1.1,2.7] P = 0.02) and 1.3 ([1.0,1.7] P = 0.07) for the first 3 months and for the full duration of follow-up, respectively.

CONCLUSIONS

Isolated surgical LV lead placement appears to carry a small but significant upfront mortality cost, with risk extending beyond the immediate postoperative period. Long-term survival is similar, suggesting those surviving beyond this period of early risk derive the same benefit as coronary sinus lead recipients. Further work is needed to identify risk factors associated with early mortality following surgical lead placement.

Future Developments in Nonsurgical Epicardial Therapies

The unique anatomic position of the pericardium in juxtaposition to central cardiac structures enables it to serve as the ideal vantage point for the delivery of novel cardiovascular therapies. Development of new tools to permit delivery of therapy in the closed pericardial space holds promise for near-surgical access to the heart, without open surgical morbidity. Early observations raise hope for the availability of epicardial leads to enhance cardiac resynchronization therapy designed for subxiphoid nonsurgical percutaneous delivery. Emerging technologies for left atrial appendage ligation may offer new strategies for preventing stroke.

Surgically placed left ventricular leads provide similar outcomes to percutaneous leads in patients with failed coronary sinus lead placement

BACKGROUND

Cardiac resynchronization therapy using a left ventricular (LV) lead inserted via the coronary sinus (CS) improves symptoms of congestive heart failure, decreases hospitalizations, and improves survival. An epicardial LV lead is often placed surgically after a failed percutaneous attempt, but whether it offers the same benefits is unknown.

OBJECTIVE

The purpose of this study was to determine if patients who receive a surgical LV lead after failed CS lead placement for cardiac resynchronization therapy derive the same benefit as do patients with a successfully placed CS lead.

METHODS

A total of 452 patients underwent attempted CS lead insertion. Forty-five patients who had failed CS lead placement and then had surgical LV lead placement were matched with 135 patients who had successful CS lead placement.

RESULTS

No major differences in preoperative variables were seen between groups. Postprocedural complications of acute renal injury (26.2% vs 4.9%, P <.001) and infection (11.9% vs 2.4%, P = .03) were more common in the surgical group. Mean long-term follow-up was 32.4 +/- 17.5 months for surgical patients and 39.4 +/- 14.8 months for percutaneous patients. At follow-up, all-cause mortality (30.6% vs 23.8%, P = .22) and readmission for congestive heart failure (26.2% vs 31.5%, P = .53) were similar between surgical and percutaneous groups. Improvement in New York Heart Association functional class (60.1% vs 49.6%, P = .17) was similar between surgical and percutaneous groups.

CONCLUSION

Surgical LV lead placement offers functional benefits similar to those of percutaneous placement but with greater risk of perioperative complications, including acute renal failure and infection.

A transatrial pericardial access: lead placement as proof of concept

A safe, easy, and quick access into the pericardial space may provide a window for diagnostics and therapeutics to the heart. The objective of this study was to provide proof of concept for an engagement and access catheter that allows access to the pericardial space percutaneously. A multilumen catheter was developed to allow navigation and suction fixation to the right atrial appendage/wall in a normal swine model. Advancement through the multilumen catheter using a second catheter with a distal needle tip allows access to the pericardial space without pericardial puncture and advancement of a standard guide wire into the space. Navigation into the pericardial space was undertaken by fluoroscopy alone and was accomplished in 10 swine (5 acute and 5 chronic). As a specific application of this pericardial access method, a pacing lead was implanted on the epicardial surface. Five chronic swine experiments were conducted with successful pacing engagement verified by lead impedance and pacing threshold and sensing. Lead impedance exceeded 1,000 Ω preengagement and dropped by an average of 200 Ω upon implant (769 ± 498 Ω). Pacing thresholds at 0.4 ms ranged from ∼0.5 to 2.1 V acutely (1.03 ± 0.92 V). No cardiac effusion or tamponade was observed in any of the acute or chronic studies. The ability to engage, maintain, and retract the right atrial appendage/wall and to engage an epicardial lead was successfully demonstrated. These findings support the feasibility of safe access into the pericardial space in a normal swine model and warrant further investigations for clinical translation.

Association of electrostimulation with cell transplantation in ischemic heart disease

BACKGROUND

Until now, cell therapy has constituted a passive therapeutic approach; the only effects seem to be related to the reduction of the myocardial fibrosis and the limitation of the adverse ventricular remodeling. Cardiac resynchronization therapy is indicated in patients with heart failure to correct conduction disorders associated with chronic systolic and diastolic dysfunction. The association of electrostimulation with cellular cardiomyoplasty could be a way to transform passive cell therapy into "dynamic cellular support." Electrostimulation of ventricles following skeletal myoblast implantation should induce the contraction of the transplanted cells and a higher expression of slow myosin, which is better adapted for chronic ventricular assistance. The purpose of this study is to evaluate myogenic cell transplantation in an ischemic heart model associated with cardiac resynchronization therapy.

METHODS

Twenty two sheep were included. All animals underwent myocardial infarction by ligation of 2 coronary artery branches (distal left anterior descending artery and D2). After 4 weeks, autologous cultured myoblasts were injected in the infarcted areas with or without pacemaker implantation. Atrial synchronized biventricular pacing was performed using epicardial electrodes. Echocardiography was performed at 4 weeks (baseline) and 12 weeks after infarction.

RESULTS

Echocardiography showed a significant improvement in ejection fraction and limitation of left ventricular dilatation in cell therapy with cardiac resynchronization therapy as compared with the other groups. Viable cells were identified in the infarcted areas. Differentiation of myoblasts into myotubes and enhanced expression of slow myosin heavy chain was observed in the electrostimulated group. Transplantation of cells with cardiac resynchronization therapy caused an increase in diastolic wall thickening in the infarcted zone relative to cells-only group and cardiac resynchronization therapy-only group.

CONCLUSIONS

Biventricular pacing seems to induce synchronous contraction of transplanted myoblasts and the host myocardium, thus improving ventricular function. Electrostimulation was related with enhanced expression of slow myosin and the organization of myoblasts in myotubes, which are better adapted at performing cardiac work. Patients with heart failure presenting myocardial infarct scars and indication for cardiac resynchronization therapy might benefit from simultaneous cardiac pacing and cell therapy.