Predictors of subclinical right ventricular dysfunction and pulmonary hypertension in asymptomatic patients with pulmonary sarcoidosis
Authors: Evsikova I.A , Bartosh-Zelenaya S.Y.U , Naiden T.V , Mamaeva O.P 
Published: November 2020

Abstract

Purpose
Identification of subclinical dysfunction of the right ventricular (RV) using modern exercise stress echo.

Methods
The main group consists of 66 patients with I-II stage of histologically verified pulmonary sarcoidosis: 42 men (63.6%) and 24 women (36.4%); mean age 31.9±5.59 years. The control group included 33 healthy, non-smokers: 24 men (72.7%) and 9 women (27.3%); average age 30.18±5.3 years. Stress-echo was performed on US system Vivid E9 (GE, USA), on a GE “e-Bike” horizontal bicycle ergometer, according to the “50x25” protocol with an increase in load every 2 min. In addition to the standard protocols, the global longitudinal RV strain (GLS RV) and systolic pressure in the pulmonary artery (SPAP, mm Hg) were assessed at rest and at the peak of exercise.

Results
RV GLS values in patients with sarcoidosis at the peak of exercise didn't increase, but rather decreased from −22.8±3.4% to 21.2±4.7% (p=0.004), unlike increased in healthy volunteers: from −24.1±2.7% to −25.1±3% (p=0.002), the whole values were within the normal range. An important fact is the decrease in the level of GLS RV in patients with pulmonary sarcoidosis (7%, p=0.00001). The estimated rest SPAP in patients with sarcoidosis was slightly higher than in healthy people (28.5±8.3 and 24.8±5.21 mm Hg.; p=0.03), but these values also didn't accede norms. At the peak of exercise, it increased greater than in the control group (32.9±10.1 and 48.36±14.4 mm Hg; p=0.000001). It was additionally revealed that in patients with sarcoidosis, GLS RV decrease by −0.8% was accompanied by an increase in SPAP by 8 mm Hg. In the control group the lower quartile of SPAP was 29 mm Hg, at the peak of exercise – 38 mm Hg. In the main group the value of SPAP exceeded the upper quartile of the control group (38 mm Hg) in 79% of cases. So we confirmed the presence of subclinical pulmonary hypertension in asymptomatic patients at the early stages of pulmonary sarcoidosis. To cut he limits of pathology in the main group, threshold GLS RV values were obtained at the peak of exercise by the method of classification trees. Values less than −21.6% were correlated with the presence of subclinical RV dysfunction with 90% rang; in combination with increase in SPAP more than 39.5 mm Hg – 100% rang. 50 patients (75% of the main group) showed an increase in SPAP at the peak of exercise more than 39.5 mm Hg. 37 patients (56%) showed GLS RV decrease less than −21.6%. Combination of these two parameters was detected in 42% of cases.

Conclusions
Thus, in 42% of young patients with sarcoidosis, latent right ventricular dysfunction was revealed at the absence of symtoms and pathological changes in resting echocardiography. Therefore, GLS RV decrease at the peak of exercise less than −21.6% with an increase in SPAP more than 39.5 mm Hg may be a predictor of subclinical cardiac dysfunction in patients with pulmonary sarcoidosis.

Funding Acknowledgement
Type of funding source: None