In the first randomised clinical trial to report the benefits of using echocardiography to guide placement of pacemaker leads, researchers found that a patient-tailored approach using software to analyse left ventricle function and guide placement of lead wires can significantly boost clinical benefits from pacemakers. The research was presented at the American College of Cardiology’s 60th Annual Scientific Session.
“Optimal placement of pacemaker leads is determined by the location of cardiac scar tissue and areas of delayed heart muscle contraction, which vary considerably among patients,” said Fakhar Z Khan, clinical research fellow, Cambridge University, Cambridge, UK. “Our improved results with an individualised approach should change the way pacemaker leads are implanted in this population of patients.”
Researchers used speckle tracking echocardiography (STE) to conduct cardiac assessments of 220 patients scheduled for cardiac resynchronisation therapy. STE is a technological advance that refines echocardiography. Several studies have confirmed that this advance is a simple, inexpensive, quick and accurate way to measure strain and function in the myocardium.
For the 110 patients randomly assigned to the test group, STE measurements guided placement of the lead wire implanted in the left ventricle. Leads for the control group were implanted conventionally, without reference to the STE data. The test group had better results than the control group on all clinical endpoints, including rates of response by reverse remodeling of the left ventricle, a measure of improvement in heart function (70% vs. 55%), and improvement on a standard scale for heart failure (83% vs. 65%).
Clinical results correlate with degree of success in directing the lead to the optimal site identified by STE. Across both groups, patients with a concordant lead – placed exactly at the target site − had the lowest combined rate of death from any cause and hospitalisation related to heart failure (8%) and better results overall. That rate was doubled (16%) for patients with a lead adjacent to the optimal site and 4.5 times higher (36%) for those with a lead remote from the optimal site. A much higher proportion of patients in the test group had concordant lead placement (61% vs. 47%).
“STE software can be applied to any existing echocardiographic image at no additional risk to the patient,” Khan said. “It makes targeting of the lead feasible at any facility that is already performing echocardiography and has the software in their system to analyse the images. That makes it widely accessible, even for small centres and non-university hospitals, where more and more pacemakers are being
implanted.”
Study participants were recruited from Papworth and Addenbrooke’s Hospitals, Cambridge, UK, and will continue to have ongoing follow-up. The study was sponsored by Papworth Hospital Foundation Trust and funded through charitable funds and the UK National Institute for Health Research.
