Long‐Term Outcomes of Cardiac Resynchronization Therapy Using Apical Versus Nonapical Left Ventricular Pacing

Abstract

BackgroundExperimental evidence indicates that left ventricular (LV) apical pacing is hemodynamically superior to nonapical LV pacing. Some studies have shown that an LV apical lead position is unfavorable in cardiac resynchronization therapy. We sought to determine whether an apical LV lead position influences cardiac mortality after cardiac resynchronization therapy.Methods and ResultsIn this retrospective observational study, the primary end point of cardiac mortality was assessed in relation to longitudinal (basal, midventricular, or apical) and circumferential (anterior, lateral, or posterior) LV lead positions, as well as right ventricular (apical or septal), assigned using fluoroscopy. Lead positions were assessed in 1189 patients undergoing cardiac resynchronization therapy implantation over 15 years. After a median follow‐up of 6.0 years (interquartile range: 4.4–7.7 years), an apical LV lead position was associated with lower cardiac mortality than a nonapical position (adjusted hazard ratio: 0.74; 95% confidence interval, 0.56–0.99) after covariate adjustment. There were no differences in total mortality or heart failure hospitalization. Death from pump failure was lower with apical than nonapical positions (adjusted hazard ratio: 0.69; 95% confidence interval, 0.51–0.94). Compared with a basal position, an apical LV position was also associated with lower risk of sudden cardiac death (adjusted hazard ratio: 0.34; 95% confidence interval, 0.13–0.93). No differences emerged between circumferential LV lead positions or right ventricular positions with respect to any end point.ConclusionsIn recipients of cardiac resynchronization therapy, an apical LV lead position was associated with better long‐term cardiac survival than a nonapical position. This effect was due to a lower risk of pump failure and sudden cardiac death.

Adherence to ESC cardiac resynchronization therapy guidelines: findings from the ESC CRT Survey II

“…It established the benefit of a CRT over medical therapy in eligible patients, but was underpowered to compare any difference between CRT-P and CRT-D. 7 The majority of comparisons of CRT-P vs. CRT-D have been retrospective cohort studies and these have suggested that the benefit for a CRT-D over a CRT-P may be limited to those patients with ischaemic heart failure aetiology. 20,33,34 The only recent RCT of defibrillator over standard care, the DANISH study, randomized 556 patients with heart failure of non-ischaemic aetiology with an LVEF ≤35% to either receive an ICD or usual clinical care. Despite the rate of sudden cardiac death being half in the ICD group (4.3%) compared with the control group (8.2%) this trial showed no significant difference in overall survival benefit between the two groups.…”

Optimizing lead placement for pacing in dyssynchronous heart failure: The patient in the lead

“…Studies that investigated whether a nonapical RV load position, closer to the His-Purkinje system, could improve outcome in CRT found no differences in echocardiographic or clinical endpoints as opposed to a conventional RV lead positon. 21 However, paced effects (eg, interlead delays)…”

“…26 Optimal LV pacing site is patient-specific Accumulated evidence in over 4200 patients from various landmark trials taught us that, on the group level, no single site is consistently superior (or inferior) to another with respect to long-term outcome. 21,27,28 Conversely, the interand intraindividual heterogeneity of the optimal LV pacing site becomes apparent in many interventional studies in which AHB was systematically explored during BVP at various sites. Pacing a suboptimal site improves the maximum rate of LV pressure rise (dP/dt max ) on average by 613%.…”

“…Three of six studies comparing image-guided LVLP with an empirical approach reported significantly more reverse remodeling and/or percentage of responders in the treatment group (Table 1). [44][45][46] However, in the TARGET (Targeted Left Ventricular Lead Placement to Guide Cardiac Resynchronization Therapy) and STARTER (Speckle Tracking Assisted Resynchronization Therapy for Electrode Region) studies, assessment of strain at the apex 21 ) Right: Alternatively, the pooled results of Derval et al 29 and other acute hemodynamic studies demonstrate the potential improvement when targeting the patient-individual optimal segment instead of a conventional location. Importantly, no single site is consistently superior to others, underscoring the unpredictability and heterogeneity of the optimal target among different patients.…”

“…could not be performed, even though an apical position may be optimal in a substantial amount of patients (Supplemental Table 2). 21 Although the utility of strain for detecting scarred segments is poor (sensitivity 33%), these positive effects cannot solely be attributed to targeting the latest mechanically activated segment. 47 In contrast to TARGET and STARTER, 2 studies allowed targeting electrically delayed segments using QLV guidance in the control group and were unable to demonstrate significant differences in reverse remodeling between both groups.…”