Evaluation of Women With Peripartum or Dilated Cardiomyopathy and Their First-Degree Relatives: The DCM Precision...

Rare variant genetics have been associated with peripartum cardiomyopathy (PPCM), but the role of genetics remains unsettled. The study sought to compare dilated cardiomyopathy (DCM) genetic risk in first-degree relatives (FDRs) of female patients (probands) with DCM or PPCM to gain causal inference, and to assess DCM-relevant rare variant prevalence in DCM/PPCM probands and population controls.

Clinical and genetic data were analyzed from the DCM Precision Medicine Study. Risk of DCM or partial DCM, where partial DCM was defined as left ventricular enlargement or a left ventricular ejection fraction of <50%, was estimated in 665 FDRs from 452 female probands, all of whom had been pregnant; 67 had PPCM and 385 had DCM; prevalence of pathogenic, likely pathogenic, or uncertain significance variants was estimated among probands.

The risk of DCM/partial DCM for FDRs of PPCM probands was similar to that for FDRs of DCM probands (hazard ratio, 0.77 [95% CI, 0.47-1.28]). Estimated DCM prevalence among the lowest-risk FDRs of non-Hispanic European ancestry probands with PPCM (7.0% [95% CI, 0%-14.1%] females, 9.0% [95% CI, 1.6%-16.3%] males) exceeded population estimates from a UK Biobank study (0.30% females, 0.63% males). Estimated prevalences of a pathogenic, likely pathogenic, or uncertain significance variant among African ancestry and European ancestry probands with PPCM were 55.4% (95% CI, 33.1%-77.7%) and 66.0% (95% CI, 38.6%-93.3%), respectively. The estimated prevalence of pathogenic/likely pathogenic variants among European ancestry PPCM probands (26.6% [95% CI, 12.6%-40.6%]) exceeded a population estimate from a UK Biobank study (0.6%).

The risk of DCM/partial DCM among FDRs was similar regardless of whether their probands had PPCM or DCM. Also, DCM-relevant rare variant findings for females with PPCM or DCM were similar and greater than in population controls, suggesting a similar causal basis for PPCM and DCM. These findings underscore the need for genetic evaluations in all patients with PPCM.

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03037632.