Trends in outcome and patient composition in dilated cardiomyopathy in Sweden over time

We studied prognosis and patient composition over time in dilated cardiomyopathy (DCM): a well-defined category of heart failure (HF), often affecting younger individuals. We expected improved prognosis over time, due to emerging diagnostic and therapeutic options.

All patients from the Swedish Heart Failure Registry (SwedeHF) fulfilling criteria for DCM (exclusion of ischemic, valvular, or alcoholic etiology and affirmed by clinical judgment in the protocol) (n=3739), were analyzed with respect to three time periods of inclusion in the registry, 2003–2007 (n=814), 2008–2011 (n=1448), 2012–2016 (n=1477), regarding mortality, transplantations, and hospital admissions during one year after inclusion.

Over the three time periods, registered cohorts were older with time (mean 59.3 years/ 60 years/ 61.0 years, p=0.0035), and the proportion of females incresased (24.1% / 27.2% / 30.7%, p=0.0006).

For clinical variables, the distribution of left ventricular ejection fraction (LVEF) with time showed significantly higher LVEF (p=0.0024), and functional classification (NYHA) showed lower class (p=0.0011). Hypertension as a comorbidity (i.e. not judged to be responsible for HF) was more frequently occurring with time: (34.0%/ 40.6%/ 44.1%, p<0.0001). As for HF treatment: use of device increased (p<0.0001 for categorical combinations), mineralocorticoid receptor antagonists (MRA) increased (41.9%/ 37.3%/ 46.7%, p=0.0023), and diuretics dropped (76.1%/ 71.1%/ 67.0%, p≤0.0001) in the different cohorts with time.

Mortality (6.9%, 5.1%, 5.5%), transplantation (0.5%, 0.8%, 0.6%) and hospital admissions for HF (28.4%, 26.3%, 24.6%) were stable over time (ns for all), whereas cardiovascular (CV) (33.8%, 33.8%, 29.7%, p=0.043) and all cause admissions (39.1%, 38.8%, 33.7%, p=0.0099) decreased. After adjustment for age, sex, LVEF, NYHA, hypertension and device treatment only all cause admissions remained significantly decreased.

In this nationwide study between 2003–2016, one-year outcome in DCM in Sweden remained stationary over time, despite advances in HF therapy. During the time period, we observed a continuous change in the clinical profile in the DCM population.

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Region Västra Götaland agreement concerning research and education of physicians.