Targeted left ventricular electrode placement did not improve outcomes in heart failure patients undergoing cardiac resynchronisation therapy, according to results presented in a Hot Line session at the 2026 ESC Congress and published simultaneously in The Lancet.
Cardiac resynchronisation therapy (CRT) is a type of pacemaker treatment for some people with heart failure who have conduction abnormalities, such as left bundle branch block (LBBB). It sends carefully synchronised electrical signals to the heart so that the lower chambers of the heart contract more effectively together.
"Although CRT improves symptoms, quality of life and survival in most patients, up to a third experience no benefit," explained principal investigator Jens Cosedis Nielsen of Aarhus University Hospital, Denmark.
"Observational data have shown that measuring a late electrical signal from the left ventricular electrode is associated with better outcomes. However, it has never been investigated in a large randomised controlled trial whether a strategy of targeted left ventricular electrode placement at the site of latest electrical activation improves outcomes," he noted.
The DANISH-CRT trial was an investigator-initiated, double-blind trial conducted at five Danish university centres performing CRT device implants. The trial included 1,000 patients with heart failure and LBBB on guideline-directed pharmacological treatment who were referred for biventricular pacing. Patients were randomised to left ventricular electrode placement targeted at the site of latest electrical activation within the coronary sinus branches or to standard electrode placement (in the posterolateral, non-apical region of the coronary sinus).
After a median follow-up of 45.8 months, the primary outcome of death or unplanned hospitalisation for heart failure occurred in similar proportions of patients with targeted electrode placement and standard placement (27.9% versus 25.5%; hazard ratio 1.10; 95% confidence interval 0.86 to 1.39; p=0.45).
Consistently similar findings were observed in secondary outcomes, including structural changes in the left ventricle, quality of life, functional status and exercise capacity, as well as in subgroup analyses of the primary outcome. Numerically, more electrode-related complications were observed in the targeted placement group.
"Our findings do not support routine electrical mapping to guide left ventricular electrode placement in contemporary CRT practice," said Cosedis Nielsen. "We will continue to analyse data from the DANISH-CRT trial to investigate which patient subgroups benefited most from CRT".
