Tissue Doppler may detect LV Dysfunction in COPD patients without pulmonary hypertension

Janne M. Hilde and colleagues from the Department of Cardiology, Oslo University Hospital-Aker, Oslo, Norway, Faculty of Medicine, University of Oslo, Oslo, Norway aimed to assess prevalence of left ventricular (LV) systolic and diastolic function in stable cohort of COPD patients, where LV disease had been thoroughly excluded in advance.

The study included a total of 100 COPD outpatients in GOLD II-IV, out of which 34 were categorised as controls. Patients were divided by invasive mean pulmonary artery pressure (mPAP) in COPD-PH (≥25 mmHg) and COPD-non-PH (<25 mmHg), which was subdivided in mPAP ≤20 mmHg and 21–24 mmHg.

LV myocardial performance index (LV MPI) and strain by tissue Doppler imaging (TDI) were used for evaluation of LV global and systolic function, respectively. LV MPI ≥0.51 and strain ≤-15.8% were considered abnormal. LV diastolic function was assessed by the ratio between peak early (E) and late (A) velocity, early TDI E´, E/E´, isovolumic relaxation time, and left atrium volume.

The authors observed that LV MPI ≥0.51 was found in 64.9% and 88.5% and LV strain ≤-15.8% in 62.2.% and 76.9% in the COPD-non-PH and COPD-PH patients, respectively.

Similarly, LV MPI and LV strain were impaired even in patients with mPAP <20 mmHg. Furhtermore, in multiple regression analyses, residual volume and stroke volume were best associated to LV MPI and LV strain, respectively.

Except for isovolumic relaxation time, standard diastolic echo indices as E/A, E´, E/E´ and left atrium volume did not change from normal individuals to COPD-non-PH.

Hence, the authors concluded that subclinical LV systolic dysfunction was a frequent finding in this cohort of COPD patients, even in those with normal pulmonary artery pressure.

However, evidence of LV diastolic dysfunction was hardly present as measured by conventional echo indices.