Submaximal Heart and Pulmonary Evaluation: A Novel Noninvasive Test to Identify Pulmonary Hypertension in Patients With Systemic Sclerosis

Abstract

Objective Pulmonary hypertension (PH) is a leading cause of death in patients with systemic sclerosis (SSc). Although right heart catheterization is the gold standard for diagnosing PH, it is an invasive test with associated risks. The submaximal heart and pulmonary evaluation (step test) is a noninvasive, submaximal stress test that could be used to identify patients with PH. The purpose of this study is to assess the correlation between change in end tidal carbon dioxide (ΔPETCO2) from rest to end-exercise on the step test and mean pulmonary artery pressure (mPAP) on RHC in SSc patients. Methods This is a retrospective cohort study of patients with limited or diffuse cutaneous SSc who were evaluated in an academic cardiology practice between November 2007 and November 2011 and underwent a step test and RHC. Statistical analysis was performed using Spearman’s correlation and multivariable linear regression. Results 679 charts were reviewed. Nineteen SSc patients who underwent a step test and RHC were included. ΔPETCO2 was negatively correlated with mPAP (r = −0.82, p-value < 0.0001). In a multivariable linear regression model evaluating the relationship between ΔPETCO2 and mPAP, controlling for age, sex, time between and order of step test and RHC, ΔPETCO2 remained the only variable statistically significantly associated with mPAP (p-value < 0.001). The step test had a sensitivity of 100%, specificity of 75%, PPV of 93.8%, and NPV of 100% for the diagnosis of PH. Conclusions ΔPETCO2 on the step test has a strong, statistically significant negative correlation with mPAP on RHC.

Diagnostic utility of sub‐maximum cardiopulmonary exercise testing in the ambulatory setting for heart failure with preserved ejection fraction

“…This non-invasive sub-maximum test has been previously shown to differentiate PAH patients from healthy controls 16 and help in the diagnosis of systemic sclerosis-associated PH. 14,15 It consists of a portable unit with a 14 cm high step that patients step up and down for three minutes. The unit is equipped with a portable metabolic cart and a mouthpiece that is connected to a continuous gas exchange analyzer.…”

“…12 More recently, sub-maximum CPET has garnered increasing attention in the diagnostic evaluation of patients with PH. [13][14][15][16] Unlike conventional CPET, a maximum exercise effort is not required, making it an attractive option for patients with cardio-pulmonary or musculoskeletal disorders and elderly patients who often are unable to undergo maximum exercise testing. While previous research have examined the diagnostic utility of sub-maximum CPET in PH, these initial studies were limited to patients with pulmonary arterial hypertension (PAH) only.…”

Comparison of change in end tidal carbon dioxide after three minutes of step exercise between systemic sclerosis patients with and without pulmonary hypertension

“…Because patients with SSc may not necessarily have the same results from the step test as those with different aetiologies of PH, further studies were needed to evaluate whether the step test might perform as well in the SSc-PH population. Our group recently published a retrospective study of 19 SSc patients who had undergone both the step test and RHC, and found that ÁP ETCO2 from rest to end-exercise on the step test was statistically significantly correlated with TABLE 2 Step test results mPAP as measured by RHC (r = À0.82, P = 0.0001) [32]. Moreover, ÁP ETCO2 on the step test had a sensitivity of 100%, specificity of 75%, positive predictive value of 93.8% and negative predictive value of 100% for the diagnosis of PH, using RHC as the gold standard [32].…”

Monitoring and Diagnostic Approaches for Pulmonary Arterial Hypertension in Patients with Systemic Sclerosis

“…In addition, DP ETCO2 was inversely correlated with mPAP on RHC (r 5 À0.82; P<.0001), whereas correlations with PASP on TTE (r 5 0.74; P 5 .0004), and FVC/DLCO were lower (r 5 0.53; P 5 .034). 63 Condliffe and colleagues 41 showed that survival of patients with SSc-PAH with exercise was better compared with patients with PAH at rest, but a significant proportion had evidence of disease progression. Identifying patients with exercise-induced PAH may be a sensitive way to detect early PAH and improve outcomes with early treatment.…”