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

Progress in Cardiac Resynchronisation Therapy and Optimisation

Cardiac resynchronisation therapy (CRT) has become the cornerstone of heart failure (HF) treatment. Despite the obvious benefit from this therapy, an estimated 30% of CRT patients do not respond ("non-responders"). The cause of "non-response" is multi-factorial and includes suboptimal device settings. To optimise CRT settings, echocardiography has been considered the gold standard but has limitations: it is user dependent and consumes time and resources. CRT proprietary algorithms have been developed to perform device optimisation efficiently and with limited resources. In this review, we discuss CRT optimisation including the various adopted proprietary algorithms and conduction system pacing.

Decision regret in implantable cardioverter-defibrillator recipients : A cross-sectional analysis on patients that regret their decision after ICD implantation

BACKGROUND

Implantable cardioverter-defibrillators (ICDs) are designed to deliver therapy in the event of malignant ventricular arrhythmias. Despite their benefits, some ICD recipients regret their decision on device implantation.

OBJECTIVES

The aim of this study was to evaluate the incidence, predictors, and consequences of recipients that regretted their decision after implantation.

METHODS

A questionnaire-based cross-sectional survey of consecutive ICD recipients examined during a routine outpatient follow-up visit was conducted. Their level of depression and anxiety was assessed with the hospital anxiety and depression scale (HADS). Quality of life (QOL) was assessed using the Minnesota living with heart failure questionnaire.

RESULTS

Of 434 ICD recipients invited to the study, 423 (97.5%) agreed and completed the survey, 349 (83%) had a primary prevention indication, and 339 (80%) ischemic cardiomyopathy. A total of 41 recipients (9.7%) regretted their decision to undergo ICD implantation. These patients were: (1) younger (63 versus 69 years), (2) more frequently in New York Heart Association (NYHA) ≥2 functional class (63% versus 22%), (3) had higher education levels (more than high-school: 76% versus 60%), (4) felt that preoperative information was lacking (22% versus 4%), (5) had more complications in the perioperative period (15% versus 3%), (6) felt less safe after ICD implantation (54% versus 5%), and (7) considered more frequently ICD deactivation during near end-of-life situations (54% versus 29%). Mean QOL and HADS scores were significantly worse in these patients (36 versus 30 and 12 versus 8.8 points, respectively; p < 0.01 for all).

CONCLUSION

Almost 10% of ICD recipients regretted their decision after implantation. Predictors included younger age, higher education levels, complicated perioperative period, and lack of preoperative information.

Phantom shocks in implantable cardioverter-defibrillator recipients: impact of education level, anxiety, and depression

BACKGROUND

Implantable cardioverter defibrillators (ICDs) are designed to deliver shocks in the event of ventricular arrhythmias. Some ICD recipients experience the sensation of ICD discharge in the absence of an actual discharge (phantom shock, PS).

OBJECTIVES

The aim of this study was to evaluate the incidence, predictors, and consequences of PS in ICD recipients.

MATERIALS AND METHODS

Consecutive ICD recipients were examined during a routine outpatient follow-up (FU) visit. Subjects completed a written survey; their level of depression and anxiety was assessed with the hospital anxiety and depression scale (HADS). Quality of life (QOL) was assessed using the Minnesota living with heart failure questionnaire.

RESULTS

Of 434 patients invited to the study, 423 (97.5%) ICD recipients agreed to and completed the survey; 349 (83%) had a primary prevention indication and 339 (80%) ischemic cardiomyopathy. A total of 27 patients (6.4%) reported a PS during a mean FU of 64 ± 44 months (5.4% in the primary prevention group and 10.8% in the secondary prevention group; p = 0.11). PS were related to higher education (≥bachelor's degree 41% versus 20%; p = 0.03), and more frequent in patients receiving adequate shocks during FU (34% versus 0.5%; p < 0.001). HADS score levels were higher following PS (15 ± 6 versus 8.8 ± 7.4; p < 0.001). The majority of patients reporting PS felt that the information provided to them prior to ICD placement was insufficient (22.2% versus 5.0%), that they needed psychological support after ICD implantation (26% versus 3%), and considered ICD deactivation in near end-of-life situations (59% versus 29%; p < 0.001 for all).

CONCLUSIONS

PS occur in 6.4% of all ICD recipients and are related to higher education and to patients that experienced adequate shocks during FU.

Outcomes of cardiac resynchronization therapy using left ventricular quadripolar leads

BACKGROUND

Quadripolar left ventricular (LV) leads provide a more optimal pacing configuration for cardiac resynchronization therapy (CRT) than conventional bipolar leads. The objective of this study is to determine the clinical outcomes of CRT using quadripolar leads.

METHODS

This study included 516 CRT patients who received bipolar LV leads (n = 278) or quadripolar LV leads (n = 238) from January 2013 to June 2016. Data were retrospectively collected from a prospective CRT database and electronic health records. CRT response to CRT was defined as >5% improvement in the LV ejection fraction (LVEF) from baseline. Baseline characteristics and outcomes were compared between groups.

RESULTS

New York Heart Association Functional Classification and LVEF significantly improved in the quadripolar and bipolar groups after CRT. There was no difference in the all-cause mortality rate. The implant success rate was significantly higher in the quadripolar group (100% vs 97.8%; P = 0.02). Quadripolar lead placement was an independent predictor of CRT response at 12 months (hazard ratio, 0.76; 95% confidence interval, 0.58-0.98; P = 0.04). The rate of LV lead-related complications requiring invasive lead revision or abandonment was significantly higher in the bipolar group (11.2% vs 4.6%; P = 0.007).

CONCLUSIONS

Quadripolar leads achieve similar CRT outcomes as bipolar LV leads but with a higher implant success rate and fewer procedure-related complications.

Innovative pacing: Recent advances, emerging technologies, and future directions in cardiac pacing

The field of cardiovascular medicine is rapidly evolving as advancements in technology and engineering provide clinicians new and exciting ways to care for an aging population. Cardiac pacing, in particular, has seen a series of game-changing technologies emerge in the past several years spurred by low-power electronics, high density batteries, improved catheter delivery systems and innovative software design. We look at several of these emerging pacemaker technologies, discussing the rationale, current state and future directions of these pioneering developments in electrophysiology.

Left ventricular three-dimensional quadripolar lead acute clinical study: the LILAC study

AIMS

This multicenter acute clinical study was designed to verify novel three-dimensional (3D) quadripolar lead designs that can achieve ≤2.5 V average pacing capture threshold (PCT) not only at the apex, but also at the base of the left ventricle with phrenic nerve stimulation (PNS) avoidance for cardiac resynchronization.

METHODS

During the implant procedure, up to two different left ventricular investigational leads were introduced and tested in the same target coronary vein based on the coronary sinus venogram in a wedged and unwedged position. Adverse events were collected in 30 days following the procedure.

RESULTS

Eighty-seven leads were tested in 50 patients. When the best performing spiral electrode was chosen from each lead testing, the average of the best PCT on spiral in a wedged position was similar to the unwedged position (1.7 ± 1.5 V vs 1.9 ± 1.5 V, P = ns) and was similar to the wedged tip electrode average PCT (1.7 ± 1.5 V vs 1.6 ± 1.6 V, P = ns). In the majority of patients (89-96%), pacing was achievable in a mid-basal ventricular location without PNS.

CONCLUSIONS

This acute study demonstrated that a 3D quadripolar spiral lead design can achieve acceptable PCTs and avoid PNS without repositioning the lead at implant in the vast majority of patients. It also demonstrated that this lead design can achieve mid-basal ventricular stimulation with low PCT and good acute stability.

Multisite left ventricular pacing in cardiac resynchronization therapy

Cardiac resynchronization therapy is an effective treatment for selected patients with heart failure and left bundle branch block dyssynchrony. Unfortunately, about a third of patients, so-called nonresponders, do not display any symptomatic or structural improvements after the treatment. In another 5% of patients, the left ventricular lead cannot be implanted due to technical limitations. Novel quadripolar pacing lead and associated multisite pacing technology has the potential to help improve both of these problems. The technology and applications of these leads are reviewed and the novel technique of multisite pacing from two poles of one quadripolar lead is discussed. This technology may improve response to cardiac resynchronization therapy for some patients.