Novel active fixation lead guided by electrical delay can improve response to cardiac resynchronization therapy in heart failure

Abstract

Aims Cardiac resynchronization therapy (CRT) for heart failure (HF) recently has shown optimal results by targeting electrically delayed sites in coronary sinus (CS) branches. However this purpose often cannot be reached because of unstable left ventricular (LV) lead position. In current study were assessed the long‐term effects of the novel active fixation LV lead in CS, guided by electrical delay (QLV), in patients with HF due to coronary artery disease. Methods One hundred eighty‐five consecutive patients underwent CRT with intraoperative evaluation of QLV in the target position of the LV lead. When the novel active fixation LV lead was available, 98 consecutive patients received it, composing the Fix group. They were compared with 87 patients with a conventional passive fixation lead (No Fix group). The final LV lead position was assessed by fluoroscopy. Clinical response to CRT was assessed within a period of about 3 years: patients experiencing HF rehospitalization and death due to HF were defined as non‐responders. Results There were no significant differences between groups in the final position of LV lead in left anterior oblique view (Pearson χ2 = 0.12; P = 0.73). In right anterior oblique view, a basal position was reached more in the Fix group (38%) than in the No Fix group (6.5%) (Pearson χ2 = 23.095; P < 0.001). QLV was significantly greater in the Fix group (122.6 ± 33.2 ms; SE = 3.6) than in the No Fix group (97.5 ± 37.8 ms; SE = 4.9) (t = 4.17; P < 0.001). Rehospitalizations for HF were 37 in the No Fix group and 14 in the Fix group. Deaths due to HF were 49 in the No Fix group and 18 in the Fix group. Survival analysis, assessed by Cox regression, showed that the Fix group had a better outcome both for HF rehospitalizations [hazard ratio (HR) = 0.48; 95% confidence interval (CI) = 0.25–0.9; P = 0.023] and death due to HF (HR = 0.55; 95% CI = 0.31–0.97; P = 0.04) in comparison with the No Fix group. Adjustment for baseline characteristics by multivariate analysis showed that an active fixation lead in CS, as a covariate, was still significant both for HF rehospitalizations (HR 0.46; 95% CI = 0.24–0.88; P = 0.019) and for death due to HF (HR 0.5; 95% CI = 0.28–0.9; P = 0.021). Conclusions The novel active fixation LV lead allowed to target sites with greater QLV. Often maximum QLV was documented in basal segments, were stability of conventional passive fixation leads is not enough. Patients receiving it experienced less HF rehospitalizations and less death due to HF. Active fixation lead in CS guided by QLV can improve long‐term prognosis in patients with HF due to coronary artery disease undergoing to CRT.

Removal of an active fixation coronary sinus pacing lead 5 years postimplant: A case report

“…[13][14][15] The use of a lead with an active-fixation mechanism inserted into a CS branch has been demonstrated to reduce the likelihood of leads dislodgments, to exhibit stable electrical performance 3,16 and to improve clinical outcomes in CRT patients. 17 However, the use of active fixation CS leads may be limited because it can be thought that their structure could potentially make its extraction more difficult. CS leads are longer, thinner, less supportive during traction and more prone to inner conductor damage in comparison to standard right atrial or ventricular leads.…”

“…Dislodgment of the CS lead or suboptimal lead placement are known to decrease CRT efficacy and reported in 3%–10% of CRT implants 13–15 . The use of a lead with an active‐fixation mechanism inserted into a CS branch has been demonstrated to reduce the likelihood of leads dislodgments, to exhibit stable electrical performance 3,16 and to improve clinical outcomes in CRT patients 17 . However, the use of active fixation CS leads may be limited because it can be thought that their structure could potentially make its extraction more difficult.…”

Untitled

“…The lower pacing threshold may be due to better contact with the LV resulting from the active fixation mechanism of the side helix. In addition, ASQ leads are associated with a lower incidence of lead dislodgement and phrenic nerve stimulation than are conventional quadrupole leads [5]. By using the side helix, which is a unique feature of ASQ leads, the stability of the basal CS, maximized by the vein diameter of the CS, is increased.…”

Atrial fibrillation and QT corrected. What is the best formula to use?

“…It approximates the time interval between the onset of depolarization and the end of repolarization of the ventricular myocardium, 1,2 but in clinical practice the QT interval is used as a marker for the time to ventricular repolarization. QT interval prolongation is associated with a risk of cardiac arrhythmias as it can cause early depolarizations, cause torsades de pointes and lead to ventricular fibrillation, causing sudden cardiac death 3–10 . Risk assessment of inpatients for QT prolongation is based on their therapeutic profile, electrolyte disturbances and demographic risk factors such as age, gender and cardiac canal disease; for these clinical implications, the QT interval is routinely measured on the ECG but this interval varies with HR, in fact, QT interval is highly dependent on HR, so that utilization of the QT interval, requires adjustment for the impact of HR on the QT interval, so it is preferable to use the corrected QT interval (QTc interval) 11 .…”

“…QT interval prolongation is associated with a risk of cardiac arrhythmias as it can cause early depolarizations, cause torsades de pointes and lead to ventricular fibrillation, causing sudden cardiac death. [3][4][5][6][7][8][9][10] Risk assessment of inpatients for QT prolongation is based on their therapeutic profile, electrolyte disturbances and demographic risk factors such as age, gender and cardiac canal disease; for these clinical implications, the QT interval is routinely measured on the ECG but this interval varies with HR, in fact, QT interval is highly dependent on HR, so that utilization of the QT interval, requires adjustment for the impact of HR on the QT interval, so it is preferable to use the corrected QT interval (QTc interval). 11 QTc interval attempt to separate the dependence of the length of the QT interval from the length of the RR interval.…”