Chronic performance of an active fixation coronary sinus lead

Paradigm Shifts in Cardiac Pacing: Where Have We Been and What Lies Ahead?

The history of cardiac pacing dates back to the 1930s with externalized pacing and has evolved to incorporate transvenous, multi-lead, or even leadless devices. Annual implantation rates of cardiac implantable electronic devices have increased since the introduction of the implantable system, likely related to expanding indications, and increasing global life expectancy and aging demographics. Here, we summarize the relevant literature on cardiac pacing to demonstrate the enormous impact it has had within the field of cardiology. Further, we look forward to the future of cardiac pacing, including conduction system pacing and leadless pacing strategies.

Clinical Predictors of Incomplete CS Lead Removal during Transvenous Lead Extraction in the Patients with Cardiac Resynchronization Therapy

BACKGROUND

Reports of coronary sinus (CS) lead removal include small studies with short implant durations. Procedural outcomes for mature CS leads removed with long duration implantation are unavailable.

OBJECTIVE

To examine the safety, efficacy, and clinical predictors for incomplete CS lead removal by Transvenous Lead Extraction (TLE) in a large, long implant duration cardiac resynchronization therapy (CRT) patient cohort.

METHODS

Consecutive patients with CRT devices in the Cleveland Clinic Prospective TLE Registry who had TLE between 2013 and 2022.

RESULTS

CS leads, n=231, implant duration = 6.1±4.0 years, removed from 226 patients were included, employing powered sheaths for 137 leads (59.3%). Complete CS lead success was achieved in 95.2% of leads (n=220) and in 95.6% of patients (n=216). Major complications occurred in 5 patients (2.2%). Patients who had the CS lead extracted 1st had significantly higher incomplete removal rates than when the other leads were 1st removed. Multivariable analysis showed that older CS lead age (OR 1.35, 95% CI 1.01-1.82; P = 0.03), and removing the CS lead 1st (OR 7.48, 95% CI 1.02-54.95; P = 0.045) were independent predictors of incomplete CS lead removal.

CONCLUSION

Complete and safe lead removal rate of long implant duration CS leads by TLE was 95%. However, CS lead age and the order that leads were extracted were the independent predictors of incomplete CS lead removal. Therefore, before the CS lead is extracted, physicians should first extract the leads from the other chambers and employ powered sheaths.

Novel lead anchor technique using an active fixation quadripolar left ventricular lead in cardiac resynchronization therapy

In this report, we present a case of successful advancement of a LV lead into tortuous vessels. This was achieved by deep engagement of the coronary sinus with a cannulation catheter by applying the anchor technique using the Medtronic Attain Stability Quad lead.

UK multicenter retrospective comparison of novel active versus conventional passive fixation coronary sinus leads

BACKGROUND

A novel active fixation coronary sinus (CS) lead, Attain Stability (AS), has been released aiming to improve targeted lead positioning. Rather than being wedged into the distal vessel, it relies on a side helix for fixation. We aimed to compare implant procedure parameters and electromechanical stability of the AS lead with passive CS leads.

METHODS

A retrospective study involving six major UK cardiac centers. Patients who received active fixation leads were compared with passive fixation lead recipients in a 1:2 ratio. The primary outcome was total lead displacements (combined macrodisplacement/microdisplacement, defined as displacements requiring repositioning procedures, an increase in threshold ≥0.5 V or pulse width ≥0.5 ms, or a change in pacing polarity).

RESULTS

A total of 761 patients were included (253 AS leads and 508 passive fixation leads), of which 736 had follow-up data. The primary endpoint rate was 31% (75/241) in the active and 43% (214/495) in the passive group (p = .002). Six patients (2.5%) in the active group and 14 patients (2.8%) in the passive group required CS lead repositioning procedures (p = 0.981). On multivariable analysis, active leads were associated with a reduction in lead displacements, odds ratio 0.66 (95% confidence interval: 0.46-0.95), p = .024. There were differences in favor of passive leads in procedure duration, 120 (96-149) versus 127 (105-155) min (p = .008), and fluoroscopy time, 17 (11-26) versus 18.5 (13-27) min (p = .0022). The median follow-up duration was similar (active vs. passive): 31 (17-47) versus 34 (16-71) weeks, (p = .052).

CONCLUSION

AS CS leads had improved electromechanical stability compared with passive fixation leads, with only minimal increases in implant procedure and fluoroscopy times.

Performance of a novel active fixation quadripolar left ventricular lead for cardiac resynchronization therapy: Attain Stability Quad Clinical Study results

INTRODUCTION

The Medtronic Attain Stability Quad lead is a quadripolar left ventricular (LV) lead with an active fixation helix assembly designed to fixate the lead within the coronary sinus and pace nonapical regions of the LV. The primary objective of this study was to determine the safety and effectiveness of this novel active fixation quadripolar LV lead.

METHODS

Patients with standard indications for cardiac resynchronization therapy (CRT) were enrolled. All patients were followed at 3 and 6 months post-implant and every 6 months thereafter until study closure. Pacing capture thresholds (PCTs) were measured at implant and each follow-up and adverse events (AEs) were recorded upon occurrence.

RESULTS

Of the 440 patients who underwent implant procedures, placement of the Attain Stability Quad lead was successful in 426 (96.8%). LV lead-related complications occurred in 10 patients (2.3%), including LV lead dislodgement in three patients (0.7%). The percentage of patients with at least one LV pacing vector with a PCT ≤2.5 V at a 6-month follow-up was 96.3%. The LV lead was successfully fixated to the prespecified pacing location in 97.4% of cases.

CONCLUSIONS

This large, multinational study of the Attain Stability Quad lead demonstrated a high rate of implant success with a low complication rate. The active fixation mechanism allowed precise placement of the pacing electrodes at the desired target region with good PCTs and a very low dislodgement rate.

Efficacy, Safety, and Performance of Isolated Left vs. Right Ventricular Pacing in Patients with Bradyarrhythmias: A Randomized Controlled Trial

Background

Considering the potential deleterious effects of right ventricular (RV) pacing, the hypothesis of this study is that isolated left ventricular (LV) pacing through the coronary sinus is safe and may provide better clinical and echocardiographic benefits to patients with bradyarrhythmias and normal ventricular function requiring heart rate correction alone.

Objective

To assess the safety, efficacy, and effects of LV pacing using an active-fixation coronary sinus lead in comparison with RV pacing, in patients eligible for conventional pacemaker (PM) implantation.

Methods

Randomized, controlled, and single-blinded clinical trial in adult patients submitted to PM implantation due to bradyarrhythmias and systolic ventricular function ≥ 0.40. Randomization (RV vs. LV) occurred before PM implantation. The main results of the study were procedural success, safety, and efficacy. Secondary results were clinical and echocardiographic changes. Chi-squared test, Fisher's exact test and Student's t-test were used, considering a significance level of 5%.

Results

From June 2012 to January 2014, 91 patients were included, 36 in the RV Group and 55 in the LV Group. Baseline characteristics of patients in both groups were similar. PM implantation was performed successfully and without any complications in all patients in the RV group. Of the 55 patients initially allocated into the LV group, active-fixation coronary sinus lead implantation was not possible in 20 (36.4%) patients. The most frequent complication was phrenic nerve stimulation, detected in 9 (25.7%) patients in the LV group. During the follow-up period, there were no hospitalizations due to heart failure. Reductions of more than 10% in left ventricular ejection fraction were observed in 23.5% of patients in the RV group and 20.6% of those in the LV group (p = 0.767). Tissue Doppler analysis showed that 91.2% of subjects in the RV group and 68.8% of those in the LV group had interventricular dyssynchrony (p = 0.022).

Conclusion

The procedural success rate of LV implant was low, and the safety of the procedure was influenced mainly by the high rate of phrenic nerve stimulation in the postoperative period.

Feasibility of RA-LV pacing in patients with symptomatic left bundle branch block: a pilot study

Several studies have reported the adverse effects of right ventricular apical pacing. Permanent His bundle pacing is proved to be the most physiological. But it can be technically difficult sometimes. One recent large multicenter randomized trial showed that pacing from left ventricular apex or mid-lateral wall has the greatest potential to prevent pacing-induced reduction of cardiac pump function (by maintaining left ventricular mechanical synchrony) and, therefore, can be considered as physiological site. In our study, we have wanted to see the outcome of left ventricular pacing through coronary sinus branch with active fixation bipolar lead as a routine pacing technique in patients with symptomatic left bundle branch block. In our study we have recruited 27 patients for left ventricular pacing through coronary sinus branch (as done in cardiac resynchronization therapy) with active fixation bipolar lead and 33 patients for right ventricular apical pacing (control) and compared left ventricular pacing with right ventricular apical pacing in patients with history of syncope with left bundle branch block in baseline electrocardiography who presented with atrio-ventricular block or prolonged HV interval (≥ 70 ms) on electrophysiology study in term of procedure and fluoroscopy time and short-term lead performance and left ventricular function. The results of our study showed that left ventricular pacing through a tributary of coronary sinus is associated with shortened QRS duration (21.10 ± 3.92 ms) and better LV function (higher left ventricular ejection fraction 64.00 ± 3.03 vs. 59.73 ± 6.73 and lower left ventricular diastolic internal diameter 4.58 ± 0.32 vs. 5.23 ± 0.40 cm) in comparison to right ventricular apical pacing. However, the total procedure time and fluoroscopy time was significantly higher (73.75 ± 11.02 vs. 63.32 ± 6.06 min and 7.08 ± 1.48 vs. 5.02 ± 1.39 min, respectively) in left ventricular pacing group. The results of this study indicate that transvenous left ventricular epicardial pacing may be an option for physiological pacing in patients with symptomatic left bundle branch block.

Explanting Chronic Coronary Sinus Leads

Cardiac resynchronization therapy (CRT) has become the gold standard for patients with systolic left ventricular function, left ventricular ejection fraction less than or equal to 35%, wide complex QRS, and symptomatic heart failure. Annual implantation volume has steadily increased because of expanding indications for CRT. Improved survival resulted in many of these patients having their CRT devices for many years and eventually requiring an increased number of device-related procedures, including coronary sinus lead revisions and replacements following a coronary sinus lead extraction.

Transvenous dual-chamber pacemaker after paediatric heart transplantation using left ventricle pacing through the coronary sinus

A 12‐year‐old child with end‐stage heart failure due to restrictive cardiomyopathy was submitted to orthotopic heart transplantation. Primary graft dysfunction required venous arterial extra‐corporeal membrane oxygenation. Heart function normalized, but complete atrioventricular block remained after 3 weeks. A dual‐chamber pacing with transvenous left ventricle pacing through the coronary sinus was performed. At 5‐year follow‐up, the patient is stable with the same pacing system and with preserved ventricular function.

Coronary Venous Lead Extraction

The increasing number of cardiac resynchronization therapy devices implanted, coupled with the increasing incidence of cardiac implantable electronic device infection, has led to a greater need for extraction of coronary venous pacing leads. The objectives of this study were to review the indications, techniques and published results of coronary venous lead extraction. In this study, we searched PubMed using the search terms "lead extraction," "coronary sinus," "coronary venous," "pacing," and "cardiac resynchronization therapy" for relevant papers. The reference lists of relevant articles were also searched, and personal experience was drawn upon. Published success rates and complications were found to be similar to those reported for non-coronary venous leads in experienced centers. However, reimplantation success differs and can be limited by vessel occlusion postextraction. The available active fixation coronary sinus lead (Attain Starfix™; Medtronic, MN, USA) is a particularly complex lead to extract, whereas limited data on the newer active fixation leads (Attain Stability™, Medtronic, MN, USA) suggest that they are less challenging to remove. The study concluded that coronary venous lead extraction presents unique challenges, especially reimplantation, that require special consideration and planning to overcome.

Starfix lead extraction: Clinical experience and technical issues

Transvenous lead extraction (TLE) of the Starfix coronary sinus (CS) active-fixation lead may be challenging, due to undeployment of fixation lobes and venous occlusion. We report our experience in Starfix TLE, in comparison with previous data. A 78-year-old male, implanted in 2009 with Starfix lead, was referred to our institution for TLE, due to infective endocarditis with lead-associated vegetations. The tip of Starfix lead was located in distant, anterior position, in the great cardiac vein, close to patent left internal mammary artery-to-left anterior descending artery anastomosis, and first-choice surgical removal had a prohibitive operative risk. Conventional dilatation beyond CS ostium, as well as the use of a standard delivery catheter, was ineffective. An off-label modification of the delivery, by cutting the distal soft tip, was successful. However, the tip of the lead fragmented and was trapped in the innominate vein. Then a gooseneck snare grasped the fragment, allowing complete retrieval. TLE of Starfix leads may be particularly challenging, especially when its tip is located in a distant anterior location. In these cases, important help may be obtained by dilatation within the CS, by means of conventional or modified delivery catheters. Only experienced operators, sometimes with non-conventional techniques, should perform TLE of Starfix leads. .

The Use of a Quadripolar Left Ventricular Lead Increases Successful Implantation Rates in Patients with Phrenic Nerve Stimulation and/or High Pacing Thresholds Undergoing Cardiac Resynchronisation Therapy with Conventional Bipolar Leads

Background

Phrenic nerve stimulation (PNS) and high pacing thresholds (HPT) hinder biventricular stimulation in patients (pts) undergoing cardiac resynchronization therapy (CRT). A new quadripolar left ventricular (LV) lead (Quartet 1458Q, St. Jude Medical) with increased number of pacing configuration, might overcome this problem.

Methods

All consecutive pts in whom a standard bipolar lead intraoperatively resulted in PNS and/or HPT (≥4.00V/1mV), received, during the same implant, a quadripolar LV lead. Aim of the study was to evaluate acute and short term outcome.

Results

26 pts [24 (92%) male, mean age 74±6 years)] with PNS (22 pts; 85%) and HPT (4 pts; 15%) were included. Permanent right ventricular pacing was the reason for broad QRS complex in 4 (15%) pts, whereas all other pts had a left bundle branch block. Severely symptomatic (NYHA Class ≥3) heart failure with reduced ejection fraction (EF 31±9%) was mostly caused by ischemic heart disease (14 pts; 54%). Idiopathic dilated cardiomyopathy and valvular heart disease were diagnosed in 6 (23%) pts each. In most (24/26, 92%) pts the use of the Quartet lead led to successful biventricular pacing due to a significant reduction in intraoperative pacing threshold (5.2V/1.0ms vs. 1.4V/0.8ms; p=0.03), which was maintained (1.2V/0.7ms) at follow-up. PNS never represented reason for failed LV pacing, neither acutely nor during follow-up.

Conclusion

Excessively HPT and/or PNS are frequently encountered when conventional bipolar leads are used for CRT. A new quadripolar LV lead increases the rate of successful biventricular stimulation. Lower pacing threshold and freedom from PNS are maintained at follow-up.

Occurrence of phrenic nerve stimulation in cardiac resynchronization therapy patients: the role of left ventricular lead type and placement site

AIMS

Unwanted phrenic nerve stimulation (PNS) has been reported in ∼1 in 4 patients undergoing left ventricular (LV) pacing. The occurrence of PNS over mid-term follow-up and the significance of PNS are less certain.

METHODS AND RESULTS

Data from 1307 patients enrolled in pre-market studies of LV leads manufactured by Medtronic (models 4193 and 4195 unipolar, 4194, 4196, 4296, and 4396 bipolar) were pooled. Left ventricular lead location was recorded at implant using a common classification scheme. Phrenic nerve stimulation symptoms were either spontaneously reported or identified at scheduled follow-up visits. A PNS-related complication was defined as PNS resulting in invasive intervention or the termination of LV pacing. Average follow-up was 14.9 months (range 0.0-46.6). Phrenic nerve stimulation symptoms occurred in 169 patients (12.9%). Phrenic nerve stimulation-related complications occurred in 21 of 1307 patients (1.6%); 16 of 738 (2.2%) in the unipolar lead studies, and 5 of 569 (0.9%) in the bipolar lead studies (P = 0.08). Phrenic nerve stimulation was more frequent at middle-lateral/posterior, and apical LV sites (139/1010) vs. basal-posterior/lateral/anterior, and middle-anterior sites (20/297; P= 0.01). As compared with an anterior LV lead position, a lateral LV pacing site was associated with over a four-fold higher risk of PNS (P= 0.005) and an apical LV pacing site was associated with over six-fold higher risk of PNS (P= 0.001).

CONCLUSION

Phrenic nerve stimulation occurred in 13% of patients undergoing LV lead placement and was more common at mid-lateral/posterior, and LV apical sites. Most cases (123/139; 88%) of PNS were mitigated via electrical reprogramming, without the need for invasive intervention.

Multicenter experience with transvenous lead extraction of active fixation coronary sinus leads

BACKGROUND/OBJECTIVE

Active fixation coronary sinus (CS) leads limit dislodgement and represent an attractive option to the implanter. Although extraction of passive fixation CS leads is a common and frequently uncomplicated procedure, data regarding extraction of chronically implanted active fixation CS leads are limited.

METHODS

We performed a retrospective cohort study of patients undergoing active fixation CS lead extraction at six centers. Patient and procedural characteristics, indications for extraction, use of extraction sheath (ES) assistance, and outcomes are reported.

RESULTS

Between January 2009 and February 2011, 12 patients underwent transvenous lead extraction (TLE) of Medtronic StarFix® lead (Medtronic Inc., Minneapolis, MN, USA). The cohort was 83% male with mean age 71 ± 14 years. Average implant duration was 14.2 ± 5.7 months (2.3-23.6). All leads but one were removed for infectious indications (67% systemic infection). At the time of explant, the fixation lobes were completely retracted in only one of the 12 cases and ES assistance was required for lead removal in all cases (58% laser, 25% cutting, 25% mechanical, and 25% femoral). The majority of cases required advancement of the sheath into the CS (75.0%) and often into a branch vessel (41.7%). One lead could not be removed transvenously and required surgical lead extraction. There were no major complications. Examination of the leads after extraction frequently revealed significant tissue growth into the fixation lobes.

CONCLUSIONS

Although TLE of active fixation CS leads can be a safe procedure in select patients and experienced hands, powered sheaths and aggressive techniques are frequently required for successful removal despite relatively short implant durations. This raises significant concern regarding future TLE of active fixation CS leads with longer implant durations.

Outcomes and predictors of difficulty with coronary sinus lead removal

With increasing coronary sinus (CS) pacemaker leads for cardiac resynchronization therapy, the need to remove these leads has risen. The purpose of this study is to describe a single center's experience with CS lead removal and to attempt to identify predictors of difficulty with lead removal and complications. We reviewed all percutaneous endocardial CS lead removals performed at our institution through February 2010. Successful removal with traction alone was considered simple while complex extractions required traction devices and/or laser sheaths. Between December 1996 and February 2010, 125 CS leads were percutaneously removed ≥1 week post-implantation from 115 patients. One attempt at CS lead extraction was unsuccessful. The average duration since implantation for the CS leads was 1.54 years (± .75 years, range 8 days to 8.24 years). The majority of the leads were removed by simple traction (n = 114, 91.2 %). The remainder were removed by femoral approach with snare (n = 3, 2.4 %), locking stylet (n = 2, 1.6 %), or locking stylet and laser sheath (n = 6, 4.8 %). Half of CS leads in place greater than 4 years required complex extraction (n = 7/14, 50 %). CS complications (n = 11 patients, 8.8 %) included CS or tributary thrombosis (n = 7/102, 6.9 %) and CS dissection (n = 4/102, 3.9 %). Major non-CS complications (n = 2 patients, 1.6 %) included a cardiac tear requiring pericardiocentesis and thoracotomy (n = 1, 0.8 %) and subclavian vein tear requiring surgical repair (n = 1, 0.8 %). Minor non-CS complications (n = 9 patients, 7.2 %) included a pneumothorax (n = 1, 0.8 %), hematoma (n = 2, 1.6 %), subclavian vein thrombosis (n = 3, x%), and blood transfusion (n = 5, 4.0 %). A longer duration since implantation and larger lead diameter were associated with complex versus simple removal (p < .0001 and p = .0009 respectively). Percutaneous CS lead removal is successful by simple traction alone in the vast majority of cases. CS leads in place greater than 4 years, however, often require complex extraction. Specific extraction techniques can be implemented when simple traction is unsuccessful without an appreciable increase in complications.

Thoracoscopic patch insulation to correct phrenic nerve stimulation secondary to cardiac resynchronization therapy

AIMS

Cardiac resynchronization therapy is an established therapy for heart failure, improving quality of life and prognosis. Despite advances in technique, available leads and delivery systems, trans-venous left ventricular (LV) lead positioning remains dependent on the patient's underlying venous anatomy. The left phrenic nerve courses over the surface of the pericardium laterally and may be stimulated by the LV pacing lead, causing uncomfortable diaphragmatic twitch. This paper describes a video-assisted thoracoscopic (VATS) procedure to correct phrenic nerve stimulation secondary to cardiac resynchronization therapy.

METHODS AND RESULTS

Most current ways of avoiding phrenic stimulation involve either electronic reprogramming to distance the phrenic nerve from the stimulation circuit or repositioning the lead. We describe a case where the phrenic nerve was surgically insulated from the stimulating current by insinuating a patch of bovine pericardium between the epicardium and native pericardium of the heart thus completely resolving previously intolerable and incessant diaphragmatic twitch. The procedure was performed under general anaesthesia with single-lung ventilation and minimal use of neuromuscular blocking agents. Surgical patch insulation of the phrenic nerve was performed using minimally invasive VATS surgery, as a short-stay procedure, with no complications. No diaphragmatic twitch occurred post-surgery and the patient continued to gain symptomatic benefit from cardiac synchronization therapy (New York Heart Association Class III to II), enabling return to work.

CONCLUSIONS

In cases where the trans-venous position of a LV lead is limited by troublesome phrenic nerve stimulation, thoracoscopic surgical patch insulation of the phrenic nerve could be considered to allow beneficial cardiac resynchronization therapy.

First prospective, multi-centre clinical experience with a novel left ventricular quadripolar lead

AIMS

Cardiac resynchronization therapy (CRT) is sometimes complicated by elevated pacing thresholds and phrenic nerve stimulation (PNS), both of which may require that the coronary sinus lead be repositioned. The purpose of this study was to evaluate the performance of a novel quadripolar electrode lead and cardiac resynchronization therapy-defibrillator (CRT-D) device that enables electrical repositioning, potentially obviating a lead reposition procedure.

METHODS AND RESULTS

Patients indicated for CRT were enrolled and received a quadripolar electrode lead and CRT-D device (Quartetmodel 1458Q and Promote Q; St Jude Medical, Sylmar, CA, USA). Electrical data, and the presence of PNS during pacing from each left ventricular (LV) configuration, were documented at pre-hospital discharge and at 1 month. Seventy-five patients were enrolled and 71 were successfully implanted with a Quartetlead. Electrical measurements were stable over the follow-up period. Ninety-seven per cent (64 of 66) of patients had one or more programmable configurations with a threshold < 2.5 V and no PNS vs. 86% (57 of 66) if only conventional bipolar configurations were considered. Physicians were able to use the increased programming options to manage threshold changes and PNS.

CONCLUSION

The new quadripolar electrode LV lead provides more programming options to address common problems faced when managing CRT patients. Electrical measurements from new vectors are comparable with conventional configurations. Furthermore, 11% of patients in the study suffered PNS on all conventional bipolar vectors.