Background: Many dilated cardiomyopathy (DCM) patients have improvement in cardiac function with therapy. TRED-HF investigated the safety and feasibility of therapy withdrawal in such patients.
Methods: 45 participants from TRED-HF, (25 – control group and 20 – therapy withdrawal group), who had cardiopulmonary exercise testing (CPET) at baseline and follow-up were included (Figure 1). Change in VE burden (number of ventricular ectopic beats per minute) during exercise between baseline and follow-up was compared between groups in the randomised phase using the Mann-Whitney test. Twenty patients in the control group had therapy withdrawn in the cross-over phase with repeat CPET at follow-up. Change in VE burden amongst these patients was compared between the control and cross-over phases using the paired samples sign test. Correlation between change in VE burden and changes in left ventricular ejection fraction (LVEF), NT-pro-BNP and peak VO2 was examined using Spearman’s correlation. Baseline VE burden was compared amongst patients who had therapy withdrawal, based on the occurrence of the primary end-point.
Findings: There was no difference in change in VE burden during exercise between the control and treatment withdrawal groups in the randomised phase (median (IQR): 0·00 [-0·09:0·10] versus 0·00 [-0·64:0·03]; p=0·438) (Figure 1). There was no difference in change in VE burden amongst the control group in the randomised phase compared to the cross-over phase (median (IQR): 0·00 [-0·09:0·10] versus 0·00 [-0·11:0·02)]; p=0·581) (Figure 1). There was no significant association between change in VE burden and change in LVEF (rs=0·079, p=0·533), NT-pro-BNP (rs=0·101, p=0·425) and VO2 (rs=0·060, p=0·642). There was no difference in baseline VE burden between patients who relapsed and those who did not (p=0·539).
Interpretation: Therapy withdrawal in recovered DCM was not associated with an increased VE burden during exercise.