Pregnancy-Associated Cardiomyopathy and Long-Term Cardiac Phenotype in Women With Truncating Titin Variants

Peripartum cardiomyopathy (PPCM) occurs in 0.02% to 0.1% of live births in European countries. Truncating variants in the Titin gene (TTNtv) are the most common genetic findings in women with PPCM. However, data on pregnancy-associated cardiomyopathy (PAC) and pregnancy tolerance among TTNtv-positive women are limited.

The objectives of the study were to report maternal cardiac outcomes during pregnancy and postpartum and fetal outcomes in women with TTNtv and to explore the effect of parity on long-term cardiac phenotype.

We conducted an ambispective cohort study including consecutive TTNtv genotype-positive women, regardless of phenotype, with ≥1 cardiological evaluation. Data on pregnancies and maternal and fetal outcomes were collected from questionnaires and medical records. Arrhythmic burden and device implantation were recorded. Left ventricular dimensions and function were assessed by echocardiography.

A total of 107 TTNtv-positive women were included (age 43 [IQR: 32-55] years, 17% probands). Among 78 women with prior pregnancies, 206 pregnancies resulted in 167 (81%) live births. PAC occurred in 3 of 167 live births and in 3 of 76 women, corresponding to a cumulative incidence of 1.8% and 3.9%. All affected women recovered completely with medical therapy. Remaining pregnancies were largely uncomplicated, without increased maternal or fetal adverse events. At median of 18 years (IQR: 9-31) after pregnancy, no differences were observed between parous and nulliparous women in arrhythmic burden, cardiac function, or ventricular dimensions.

In this TTNtv-positive cohort, PAC incidence appeared higher than reported PPCM rates in the general European population. However, pregnancy was well tolerated and was not associated with adverse long-term cardiac remodeling.