Titin mutations and female sex characterize dilated cardiomyopathy in the elderly

Abstract Aims Dilated cardiomyopathy (DCM) is frequently caused by genetic factors. Studies identifying deleterious rare variants have predominantly focused on early-onset cases, and little is known about the genetic underpinnings of the growing numbers of patients with DCM who are diagnosed after 60 years of age (i.e. late-onset DCM). The aim is to investigate the prevalence, type, and prognostic impact of disease-associated rare variants in late-onset DCM patients. Methods and results We analysed a population of late-onset DCM patients who had undergone genetic testing in seven international tertiary referral centres worldwide. A positive genotype was defined as the presence of ‘pathogenic’ or ‘likely pathogenic’ (P/LP) variants. The study outcome was all-cause mortality. 184 patients over age 60 years (56% females, mean age 67 ± 6 years, mean left ventricular ejection fraction 32 ± 10%) were studied. Sixty-six patients (36%) were carriers of a P/LP variant. Titin truncating variants (TTNtv) were the most prevalent (present in 25% of the total population and accounting for 69% of all genotype-positive patients). During a median follow-up of 42 months (interquartile range: 10–115), 23 patients (13%) died; 17 of these (25%) were carriers of P/LP variants while six patients (5.1%) were genotype-negative (P < 0.001). Conclusions In the largest series worldwide, to date, of patients with late-onset DCM, we found a high prevalence of female sex and a high genetic mutation burden, largely due to TTNtv. Patients with a positive genetic test had higher mortality than genotype-negative patients. These findings support the extended use of genetic testing also in the elderly.