332 RIGHT VENTRICULAR STRAIN IN FABRY CARDIOMYOPATHY: PROGNOSTIC IMPLICATIONS


 Left ventricular (LV) hypertrophy is the main feature of Fabry cardiomyopathy (FC), but the right ventricle (RV) is also frequently affected. Previous studies failed to demonstrate an independent association between RV hypertrophy or conventional parameters of RV function and the occurrence of adverse outcomes in patients with FC. Nevertheless, if RV free wall strain (RV-FWS), assessed by 2D speckle tracking analysis, may provide a better prognostication is currently unexplored.
 We retrospectively evaluated the association between RV-FWS and the occurrence of cardiovascular events in a cohort of 28 patients with FC. The study endpoint comprises the occurrence of cardiovascular mortality, severe heart failure symptoms, new-onset atrial fibrillation, bradyarrhythmias requiring pacemaker implantation and sustained ventricular tachyarrhythmias.
 The median value of RV-FWS was 21.4% (interquartile range:17.1-23.9%) and a total of 18 (64%) patients showed reduced RV-FWS (<23%). During a median follow-up of 49 (IQR: 37-51) months, 17 (61%) patients met the study endpoint. A ROC-curve analysis confirmed the previously defined threshold of reduced RV-FWS (23%) as the best cut-off for predicting cardiovascular outcomes at 4 years (area under curve: 0.76; p-value=0.018), but with a lower predictive value in comparison to left-sided parameters (Panel A). Kaplan-Meier survival curves showed significantly lower event-free survival at 4 years in patients with impaired RV-FWS as compared to patients with preserved RV-FWS (log rank p=0.013) (Panel B). On univariable Cox regression analysis, RV-FWS expressed as continuous variable was significantly associated with the study endpoint (Hazard ratio [HR]: 0.85, 95% CI: 0.75-0.96, p=0.009). RV-FWS retained an independent association with outcomes after alternative adjustment for age (p=0.048) or indexed LV mass (p=0.036). Conversely, RV-FWS was not significantly associated with cardiovascular events, after correcting for LV global longitudinal strain or indexed left atrial volume (p=0.401 and p=0.208; respectively).
 In Conclusion, impaired RV-FWS was not independently associated with the occurrence of cardiovascular events in FC, confirming previous observations that prognosis is mainly driven by the severity of LV cardiomyopathy.