Significant Clinical Indexes of Exercise-Induced Pulmonary Hypertension in Patients With Connective Tissue Disease

Abstract

Background: Pulmonary hypertension (PH) is an important cause of morbidity in patients with connective tissue disease (CTD), and an early stage of PH could present as exercise-induced PH (EIPH). This study investigated the significant clinical indexes of EIPH in patients with CTD. Methods and Results: We enrolled 63 patients with CTD who did not have PH at rest. All patients underwent the 6-min walk test (6MWT), and systolic pulmonary artery pressure (SPAP) was evaluated on echocardiography before and after 6MWT. EIPH was defined as SPAP ≥40 mmHg after 6 WMT. Thirty-five patients had EIPH. On univariate logistic analysis, SPAP at rest, log brain natriuretic peptide (BNP), vital capacity (VC), and forced expiratory volume in 1 s (FEV1.0) were significantly correlated with EIPH. On multiple logistic analysis, SPAP at rest and VC were independent predictors of EIPH, whereas FEV1.0 and log BNP were not significantly associated with EIPH. The area under the receiver operating characteristics curve between EIPH and BNP, SPAP at rest, VC or FEV1.0 was 0.67, 0.76, 0.74, and 0.75, respectively. Conclusions: SPAP at rest and respiratory function, especially VC, could be independent predictors of EIPH in patients with CTD.

Exercise-Induced Pulmonary Hypertension: A Valid Entity or Another Factor of Confusion?

“…A retrograde transmission of high LAP to the pulmonary arteries explains most of the rise in mPAP [ 7 ]. Hence, EIPH appears to be associated with increased LV filling pressure upon exertion, in the context of significant diastolic dysfunction (grade II or III) [ 10 , 11 , 12 ]. In addition, increased LAP due to LV failure, aortic stenosis or mitral stenosis (MS) may result in elevated mPAP on exertion [ 3 ].…”

“…This will end up in time causing permanent changes in the pulmonary vasculature and the development of PH at rest. The loss of pulmonary vascular distensibility alone results in poor exercise adaptation and reflects lung pathology (e.g., chronic obstructive pulmonary disease (COPD), interstitial lung disease) [ 3 , 10 , 14 , 15 ]. Therefore, EIPH without concomitant abnormal elevation in LAP more likely reflects early pulmonary vascular disease, rather than pathology of the left heart (e.g., heart failure, valvular diseases, etc.)…”

“…The occurrence of EIPH is present in a wide spectrum of left heart diseases, LV diastolic dysfunction, pulmonary vascular diseases, COPD, auto-immune diseases (e.g., scleroderma) and often a combination of those entities [ 17 , 18 ]. Furthermore, EIPH could be a potential marker for the risk of PH establishment in patients with connective tissue disorders [ 10 ]. Additional experimental and clinical studies are important for a better understanding of EIPH’s underlying pathology and interplay with nosology.…”

Evaluation of pulmonary arterial pressure in patients with connective tissue disease‐associated pulmonary arterial hypertension by myocardial perfusion imaging

“…Connective tissue disease (CTD) is an autoimmune disease that is mainly characterized clinically by involvement of multiple systems (Klemm et al, 2019. Pulmonary arterial hypertension (PAH) is a complex and severe complication of CTD and has high mortality (Ojima et al, 2019). CTD-PAH accounts for one-fourth of all PAH cases and has a worse prognosis than other types of PAH, posing a serious threat to human health (Condliffe & Howard, 2015).…”