Prognostic value of pulmonary circulation parameters in patients with idiopathic recent-onset dilated cardiomyopathy

Heart failure (HF) is among the most important causes of morbidity and mortality in developed countries. A less documented subset of patients includes those with recent-onset dilated cardiomyopathy (RODCM), typically defined as newly diagnosed dilated cardiomyopathy (DCM) with heart failure symptoms appearing within the past six months.

Since more extensive data about prognosis of patients with myocarditis or inflammatory cardiomyopathy are available, our study focuses purely on patients with idiopathic DCM. The study aims to evaluate pulmonary circulation parameters (PCP) obtained through cardiovascular magnetic resonance (CMR) in patients with RODCM and to assess its prognostic value in predicting improvements in the systolic and diastolic function.

Patients with a baseline CMR examination and transthoracic echocardiography (TTE) and a follow-up clinical examination with TTE performed after one year were retrospectively included. The PCP, namely pulmonary transit time (PTT), corrected pulmonary transit time (PTTc) and pulmonary transit beats (PTB), were assessed using a first-pass perfusion CMR sequence. Diastolic function was assessed with the TTE, and systolic function by both TTE and CMR.

The differences between baseline and follow-up left ventricle ejection fraction (LVEF), end-diastolic diameter (EDD), E/e´, and other parameters were calculated, and their correlations with baseline PCP were assessed.

Sixty four patients with RODCM and myocarditis excluded according to the endomyocardial biopsy, were included. On average, LVEF improved from 26.9% to 40.8%, EDD reduced from 64.6 mm to 60.8 mm and E/e´ from 12.5 to 9. PTT, PTTc, and PTB did not correlate with a change of EF LV or EDD, but all three correlated with the difference of E/e´ and diastolic function improvement assessed by TTE.

To our knowledge, this is the first study focused specifically on RODCM patients with EMB-excluded myocarditis and PCP as potential predictors of outcomes. Our findings show that none of the parameters correlated with the difference of the LVEF or EDD, but all PTT, PTTc and PTB correlated with the difference of E/e´ and diastolic function improvement.