Impact of interstitial lung disease on left ventricular myocardial function

BACKGROUND

Interstitial lung disease (ILD) comprises a wide variety of pulmonary parenchymal disorders within which progressive fibrosing ILD (PF-ILD) constitutes a phenotypic subset. By use of speckle tracking-based strain analysis we aimed to evaluate the degree of left ventricular (LV) dysfunction in progressive vs. non-progressive fibrosing ILD (non-PF-ILD).

METHODS

A total of 99 ILD patients (mean age 63.7 ± 13.5 years, 37.4% female), composed of 50 PF-ILD and 49 non-PF-ILD patients, and 33 controls were prospectively enrolled and underwent conventional and speckle tracking echocardiography. Additional laboratory and pulmonary function testing, as well as six-minute walk test were performed.

RESULTS

As compared to the non-PF-ILD cohort, PF-ILD patients exhibited a significantly impaired forced vital capacity (2.4 ± 1.0l vs. 3.1 ± 0.9l, p = 0.002), diffusion capacity for carbon monoxide (DLCO, 25.6 ± 16.3% predicted vs. 43.6 ± 16.67% predicted, p <0.001) and exercise capacity response as measured by the six-minute walk test distance (268.1 ± 178.2m vs. 432.6 ± 94.2m, p <0.001). Contrary to conventional echocardiographic LV parameters, both regional and global longitudinal LV strain measurements were significantly altered in ILD patients as compared to controls. No differences in LV strain were found between both patient groups. Significant correlations were observed between global longitudinal strain, on the one hand, and systemic inflammation markers, total lung capacity (TLC) and DLCO, on the other hand (high-sensitivity C-reactive protein: Pearson´s r = -0.30, p< 0.001; interleukin-6: Pearson´s r = -0.26, p = 0.007; TLC % predicted: Pearson´s r = 0.22, p = 0.02; DLCO % predicted: Pearson´s r = 0.21, p = 0.02).

CONCLUSIONS

ILD is accompanied by LV dysfunction. LV functionality inversely correlates with the severity of the restrictive ventilatory defect and inflammation marker levels. These observations support the assumption of persistent low-grade systemic inflammation that may link systemic cardiovascular function to ILD status.

High prevalence of peripheral and carotid artery disease in patients with interstitial lung diseases

Background: Interstitial lung diseases (ILD) are a heterogenous group of diseases, which have pulmonary fibrosis, restrictive lung disease, and decreased diffusion capacity as a common final path. Premature death frequently results not from ILD itself but from comorbidities. Peripheral artery disease (PAD) is a common comorbid disease in different chronic lung diseases. The focus of the present study is to clarify the prevalence of PAD in ILD. Patients and methods: A total of 97 patients with ILD and 30 controls were included in the study. Patients with ILD were subdivided into two groups according to the progression of pulmonary fibrosis: progressive fibrosing and non-progressive fibrosing ILD (PF-ILD and nPF-ILD, respectively). All participants underwent standard angiological and pneumological diagnostic procedures including six-minute walking test, measurement of ankle-brachial-index, and colour-coded duplex sonography. Results: We observed no relevant differences in the baseline characteristics except age. Both, PF-ILD and nPF-ILD patients, presented with a highly increased incidence of atherosclerotic lesions compared to the control group (p<0.001). PAD was present in all patients with PF-ILD and in 73% of patients with nPF-ILD. These results were confirmed by age-adjusted regression analyses. Conclusions: The present results indicate that ILD is an independent risk factor for atherosclerosis. Patients with PF-ILD are more severely affected than nPF-ILD patients with age as a confounding variable. Atherogenesis in ILD may be mediated by increased cardiovascular risk, systemic inflammation and chronic hypoxemia.