Assessment of right ventricular reserve utilizing exercise provocation in systemic sclerosis

Area of Science:

• Cardiology
• Rheumatology
• Pulmonary Hypertension Research

Background:

• Right ventricular (RV) function is critical for outcomes in pulmonary hypertension (PH), a common complication of systemic sclerosis (SSc).
• Assessing RV reserve capacity under stress is crucial for understanding PH progression in SSc.
• Current resting assessments may underestimate RV limitations in SSc patients.

Purpose of the Study:

• To evaluate if supine bicycle echocardiography (SBE) combined with RV longitudinal systolic strain (RVLSS) can detect limitations in RV reserve in SSc patients.
• To investigate the impact of varying afterload conditions on RV contractile response during exercise in SSc.
• To identify subclinical RV impairments missed by resting echocardiography.

Main Methods:

• Prospective study of 56 SSc patients undergoing SBE with comprehensive RV functional parameter assessment at rest and peak exercise.
• RV longitudinal systolic strain (RVLSS) was measured globally and segmentally.
• Patients were stratified based on resting RV systolic pressure (RVSP) to analyze the effects of loading conditions on RV function.

Main Results:

• Reduced global RVLSS at rest was observed, with relative hypokinesis in mid and apical segments.
• Global RVLSS increased with exercise, but basal RV contractility showed no further augmentation.
• Patients with RVSP < 35 mmHg showed increased RVLSS with exercise, indicating reserve, while those with RVSP ≥ 35 mmHg exhibited no increase and signs of exertional RV dilation.

Conclusions:

• Exercise provocation using SBE and RVLSS effectively identifies differential regional RV contractile responses in SSc.
• Increased loading conditions significantly impact RV contractile response during exercise in SSc patients.
• Subclinical impairments in RV reserve exist in SSc patients, potentially unmasked by stress testing.