Relation between recovering right ventricular function and appropriate ICD Therapy

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Right ventricular fractional area change (RVFAC) as right ventricular function is recently referred as an independent predictor of sudden cardiac death (SCD). Light ventricular function is related with SCD and adopted as a criteria of ICD implantation for primary prophylaxis. The purpose of this study was to evaluate the association of RVFAC and appropriate ICD therapy. METHODS: Consecutive patients who underwent initial ICD implantation for any diseases except for hypertrophic cardiomyopathy and Brugada syndrome and long QT syndrome were retrospectively enrolled from 2012 to 2018. Transthoracic echocardiographic parameters before ICD implantation were evaluated to investigate the association with appropriate ICD therapy. We analyzed RV function of patients undergoing echocardiography one year after implantation. RVFAC was measured by one physician and one echocardiologist. RESULTS: In total, 172 patients (60.3±13.6 years, 131 males) including 63 ischemic cardiomyopathy were enrolled. Ninety patients received an ICD as a secondary prophylaxis. Mean LVEF and RVFAC were 38.3±14.3% and 35.8±8.82%, respectively. There was no correlation between RVFAC and LVEF (correlation coefficient =0.274). Regarding appropriate ICD therapy events, the best cut-off value of RVFAC was 34.8%. The odds ratio of low RVFAC was 2.731 (95%CI: 1.456-5.121, P<0.001, Fig.1). Secondary prophylactic cohort with low RVFAC significantly showed highest incidence of appropriate ICD therapy. In multivariate analysis, only low RVFAC was an independent predictor of appropriate ICD therapy (hazard ratio 3.53, 95%CI:1.78- 6.99, P<0.001). Among patients with RV dysfunction, RVFAC was normalized in 39% patients during follow up. This recovered group showed significantly lower incidence of appropriate ICD therapy than non-recovered group (P=0.037). In multivariate analysis, recovered RVFAC was related to decrease of appropriate ICD therapy rather than recovered LVEF. In patents without LV dysfunction, recovered RVFAC was significantly associated with lower incidence of ICD therapy (P=0.023, Fig.2) CONCLUSION: RVFAC and RV function improvement may be important to stratify the prognosis of ICD patients. [Figure: see text] [Figure: see text]