Echocardiographic assessment of pulmonary artery systolic pressure following treadmill stress testing

Aims

The use of treadmill stress echocardiography (SE) for the diagnosis of nascent pulmonary hypertension (PH) has been hampered by a lack of well-defined, post-exercise pulmonary artery systolic pressure (PASP) values across representative age groups in a normal cohort.

Methods and results

Five hundred and eleven subjects (mean age: 53 ±14, 68% female) with normal resting PASP were included in the study. All participants performed treadmill exercise using the Bruce protocol to a high level of perceived exertion. PASP was calculated before and immediately after exercise using Doppler assessment of tricuspid regurgitation. For the cohort, post-exercise PASP was 39 ± 7 mmHg (range: 23-64 mmHg) representing an increase of 11 ± 6 mmHg (44%) from resting values (P < 0.001). The 95th centile values for post-exercise PASP were calculated for the following age cohorts: <30 years; 46 mmHg, 31-50 years; 50 mmHg, 51-70 years; 52 mmHg, >70 years; 53 mmHg. There was a modest independent correlation between post-exercise PASP and (i) increasing age and (ii) resting PASP (r2 = 0.35 and 0.49, respectively, P = 0.01).

Conclusion

An increase of post-exercise PASP was seen in all patients undergoing SE in this study. Age was directly correlated with post-exercise PASP. Using normative data from healthy controls, treadmill SE-derived post-exercise PASP may be a useful adjunct in the diagnosis of PH.

Abnormal pulmonary vascular responses in patients registered with a systemic autoimmunity database: Pulmonary Hypertension Assessment and Screening Evaluation using stress echocardiography (PHASE-I)

Patients with autoimmune disease, and in particular limited systemic sclerosis (CREST syndrome), are at risk of developing pulmonary artery hypertension (PAH) which is associated with a poor prognosis. With improvements in therapy offering improved survival and functional capacity, there has been an emphasis on screening to identify patients at risk. Assessment of patients during exercise may enable early identification of patients with this condition.

AIMS AND METHODS

We aimed to assess the ability of exercise stress echocardiography to evaluate the change in pulmonary artery pressure in 51 patients with autoimmune disease (systemic lupus erythamatosus (SLE), limited systemic sclerosis (LSS or "CREST") and diffuse systemic sclerosis (DSS)). Systolic pulmonary artery pressure (sPAP) was estimated using interrogation of the tricuspid incompetence jet before and after exercise. PAH was classified as normal, mild, moderate or severe using echocardiographic assessment of sPAP.

RESULTS

We were able to estimate pre-exercise and post-exercise sPAP in 92% and 90% of patients, respectively. Pulmonary pressures rose or remained unchanged in all screened individuals, with a mean rise during stress of 14.1mmHg (+/-1.1). Pulmonary artery pressure rose significantly in each of three subgroups (p<0.05). Stress echocardiography demonstrated PAH (using a cut-off of >35mmHg) in 59% of all individuals with systemic autoimmunity.

CONCLUSION

Stress echocardiography is a useful tool in identifying individuals with autoimmune disease who may have underlying pulmonary arterial disease that may be amenable to therapy. We noted a consistent elevation in sPAP across all autoimmune subtypes, suggesting an abnormal pulmonary vascular response to exercise exists in these patients.