Sex Differences in Prognosis of Patients With Genetic Dilated Cardiomyopathy

Background: Dilated cardiomyopathy (DCM) is a genetically heterogeneous disease, presenting diverse clinical phenotypes and outcomes based on the underlying gene affected. The influence of sex on the gene-specific long-term prognosis of patients with genetic DCM remains unclear. This study aims to determine the effect of sex on the long-term prognosis per underlying genogroup. Methods: A retrospective cohort study was conducted using data from 4 international referral centers. Baseline and longitudinal clinical data of patients with DCM, with a median follow-up of 6.7 years (interquartile range, 3.5-11.9 years), were collected. The study included men and women with DCM who had undergone genetic testing. Patients were categorized into 7 genotype groups: cytoskeletal/Z-disk, desmosomal, nuclear envelope, motor sarcomeric, TTN, other genetic, and genotype negative. The main outcomes measured were left ventricular reverse remodeling, mortality, heart failure hospitalization, heart transplantation, and malignant ventricular arrhythmias. Results: Among 1716 patients, 1130 (66%) were men and 510 (30%) had a (likely) pathogenic variant. Ventricular remodeling was gene-dependent in women, with TTN patients exhibiting the highest rate (P=0.003) and desmosomal patients the lowest (P=0.04) compared with the genotype-negative group. After a median follow-up of 6.7 years, 334 men (29%) and 140 women (24%) reached the primary end point. Men with a (likely) pathogenic variant had the poorest prognosis, showing a higher rate of major adverse events (adjusted hazard ratio, 1.48 [95% CI, 1.12-1.95]; P=0.02) and malignant ventricular arrhythmias (adjusted hazard ratio, 1.83 [95% CI, 1.16-2.88]; P=0.009) compared with genotype-negative women. Prognosis varied by gene in men (log-rank P<0.0001) but not in women (log-rank P=0.1). The cytoskeletal/Z-disk, desmosomal, and nuclear envelope groups had the worst prognosis in men. Conclusions: The genetic architecture and sex are critical predictors of left ventricular reverse remodeling and long-term prognosis in DCM. These factors should be integrated into individualized risk prediction models to enhance clinical outcomes in patients with DCM.