Ventricular tachycardia may predict death in non-ischaemic cardiomyopathy patients

Ventricular tachycardia predicts all-cause death and non-sudden cardiovascular death (NSCVD) in patients with non-ischaemic cardiomyopathy, a study suggests.

Non-ischaemic cardiomyopathies can lead to end-stage heart failure, ventricular tachycardia, and sudden cardiac death. Implantable cardioverter defibrillators (ICDs) can terminate ventricular tachycardia and prevent sudden cardiac deaths.

“However, the mortality benefit from ICDs has been limited in recent trials, suggesting that ventricular tachycardia may also be associated with NSCVD,” said Dr Sharif Omara from the Willem Einthoven Center for Cardiac Arrhythmia Research and Management, Leiden, the Netherlands, during his presentation at EHRA 2023.

As such, Omara and colleagues sought to evaluate the effect of ventricular tachycardia on all-cause death and NSCVD in individuals with ICDs. They merged two multicentre cohorts – the DANISH (n=556) and the DCM-VT (n=281) populations.

The DANISH trial included non-ischaemic cardiomyopathy patients with left ventricular ejection fraction (LVEF) of ≤35 percent and no prior ventricular tachycardia. Those in the DCM-VT study were consecutive non-ischaemic cardiomyopathy patients with any LVEF who underwent ablation for sustained ventricular tachycardia.

Before matching, the incidence of LVEF was significantly lower in the DANISH vs the DCM-VT cohort (25 percent vs 35 percent; p<0.001). The significance was lost after matching.

The primary endpoint was a combination of all-cause death, heart transplantation, or left ventricular assist device implantation. Overall, about 18 percent of participants experienced the primary outcome. Nine percent experienced the secondary endpoint of NSCVD. More than a third had sustained ventricular tachycardia.

“There was a lower incidence of ventricular tachycardia in the DANISH vs the DCM-VT cohort,” Omara noted. “[However,] it should be noted that this actually refers to ventricular tachycardia occurrence for the DANISH group, whereas for the DCM-VT cohort, it was ventricular tachycardia recurrence.”

An important predictor

On multivariate analysis, the most notable significant predictor for all-cause death was ventricular tachycardia at baseline after a median follow-up of 3.9 years (hazard ratio [HR], 4.27, 95 percent confidence interval [CI], 2.6–7.03; p=0.00).

It remains to be seen though whether the poor outcome was limited to participants who had an unsuccessful ablation given the lack of subanalysis, Omara noted, as the results represent the entire cohort, which encompasses those who have had both successful and non-successful ablations for ventricular tachycardia.

Other significant predictors for all-cause death were age per year increase (HR, 1.02, 95 percent CI, 1.01–1.04; p=0.01), low estimated glomerular filtration rate (<50 mL/min/1.73 m²; HR, 1.71, 95 percent CI, 1.15–2.53; p=0.01), and LVEF per 1 percent (HR, 0.96, 95 percent CI, 0.94–0.98; p=0.00).

“[These results suggest that] ventricular tachycardia occurrence appears to be an important predictor of NSCVD, as well as all-cause death, in non-ischaemic cardiomyopathy patients, independent of other markers of heart failure severity,” said Omara.

“[Hence,] ventricular tachycardia may be a marker of progressive disease and remodelling that could be incorporated into risk stratification to help predict the deterioration and need for heart transplantation,” Omara concluded.