Prevalence and Evolution of Right Ventricular Dysfunction Among Different Genetic Backgrounds in Dilated...

Titin (TTN)-related dilated cardiomyopathy (DCM) has a higher likelihood of left ventricular reverse remodelling compared with other genetic etiologies. No data regarding the evolution of right ventricular dysfunction (RVD) according to genetic background are available.

Consecutive 104 DCM patients with confirmed pathogenic genetic variants (51 TTN-related DCM; 53 other genetic DCM) and a control group of 139 patients with negative genetic testing and available follow-up data at 12-24 months were analysed. RVD was defined as a right ventricular fractional area change (RVFAC) < 35%. The main study end point was the comparison of the evolution of RVD and the change of RVFAC throughout the follow-up according to etiology. A composite of all-cause mortality and heart transplantation was included as outcome measure.

At enrollment, RVD was present in 29.1% of genetically positive DCM without differences between genetic cohorts. At 14 months follow-up, 5.9% of TTN-related DCM patients vs 35.8% of other genetic DCM patients had residual RVD after treatment (P < 0.001). Accordingly, RVFAC significantly improved in the TTN-related DCM cohort and remained stably impaired in other genetic DCM patients. However, the evolution of RVD was similar between TTN-related DCM and patients without a genetic mutation. After adjusting for RVD at follow-up, no differences in the outcome measure were seen in the study cohorts.

The evolution of RVD in DCM is heterogeneous in different genetic backgrounds. TTN-related DCM is associated with a higher chance of RVD recovery compared with other genetic etiologies.