183 Ventricular response to hand-grip exercise stress does not predict relapse of recovered dilated cardiomyopathy

Background In the TRED-HF randomized trial, withdrawal of therapy for patients with recovered dilated cardiomyopathy (DCM) resulted in a 40% relapse rate by 6 months. Predicting which patients are likely to relapse would be useful. An abnormal LV volumetric response to isometric hand grip exercise (IHGE) might reflect the fragility of recovery. Objective To identify markers of relapse using cardiac magnetic resonance (CMR) imaging during IHGE in patients with recovered DCM. Methods Patients with recovered DCM (defined as the absence of symptoms, LVEF of 50% or more, normal LVEDVi and NTPro BNP less than 250 ng/l) after a previous diagnosis of DCM, recruited in to the TRED-HF trial, underwent CMR before and during IHGE (40% of maximum grip strength for 3 mins). Physiological metrics including heart rate and blood pressure were recorded. An independent expert in CMR blinded to patient outcomes reported the scans retrospectively. Student's t test was used to compare means. All means are reported with standard deviation (SD). A p-value of <0.05 was considered significant. Spearman's rank correlation (R2) was used to determine linear associations. Results 45 patients completed the CMR IHGE protocol. Patients that relapsed after withdrawing therapy tended to have a higher LVEDV and lower LVEF after IHGE as compared to patients that did not relapse but this did not reach statistical significance [(ΔLVEDV 14 ± 18 ml vs 7 ± 13; p 0.12), (ΔLVEF -2 ± 5% vs 0 ± 6%; p 0.19)]. There was no difference in the change in strain (-0.4 ± 3.2% vs -0.8 ± 3.4%; p 0.69), change in cardiac output (0.4 ± 0.8 l/min vs 0.5 ± 1.0 l/min; p 0.62) and change in LA volume (3 ± 12 ml vs 1 ± 11 ml; p 0.48). Change in LVEF with IHGE at baseline showed a weak correlation with LVEF at 6 months follow-up (R2 = 0.12). Conclusion CMR derived volumetric measurements during isometric hand grip exercise did not predict the risk of relapse after withdrawing therapy from patients with recovered DCM. Better predictors of relapse are required before recommending therapy withdrawal from selected patients with recovered DCM. Conflict of Interest None