Ratio of pulmonary artery diameter to ascending aortic diameter and severity of heart failure

Abstract

Background: Treatment decisions in dilated cardiomyopathy (DCM) patients with severe heart failure (HF) and short clinical history are challenging because of the difficulty of determining HF stage or prognosis in the acute HF phase. We hypothesized that persistent decreased systemic or increased pulmonary arterial pressure, including in the sub-clinical phase, might affect the main pulmonary artery diameter (PAD), ascending aortic diameter (AoD), and their ratio (PAD/AoD). This study assessed AoD, PAD, and PAD/AoD by non-contrast computed tomography scans in DCM patients in the acute phase of HF and examined the association of these parameters with their clinical course.

Methods: Of 261 screened individuals, we studied 110 consecutive hospitalized patients with DCM suspected of being in advanced stage of HF and 45 age-matched controls, assessing clinical data and later events (cardiac death or left ventricular assist device implantation).

Results: Compared with controls, DCM patients had smaller AoD (26.6 ± 4.4 vs 30.6 ± 2.7 mm) and larger PAD (27.7 ± 3.5 vs 25.4 ± 2.8 mm) and PAD/AoD (1.05 ± 0.14 vs 0.83 ± 0.08; all p < 0.01). DCM patients with high PAD/AoD (median, > 1.05) had more frequent past HF hospitalizations, lower blood pressure, stroke volume, and ejection fraction, higher brain natriuretic peptide levels, smaller AoD, and similar PAD compared with patients with a low PAD/AoD. A higher PAD/AoD was associated with poorer outcomes even after adjusting for age, blood pressure, ejection fraction, or number of hospitalizations.

Conclusion: Assessment of AoD and PAD may have important clinical implications in determining whether DCM patients are in an advanced stage of HF with a poorer prognosis.

Keywords: dilated cardiomyopathy; heart failure; non-contrast computed tomography; prognosis; ratio of main pulmonary artery diameter to aortic diameter.