Isolated increases in tricuspid regurgitation velocity during exercise in dyspneic patients without risks for...

An isolated increase in tricuspid regurgitation velocity (TRV) during exercise stress echocardiography is frequently observed in patients with dyspnea, even in the absence of E/e' elevation. However, the pathophysiological and prognostic significance of this finding, particularly in patients without risk factors for pulmonary hypertension (PH), remains uncertain.

Patients who underwent bicycle exercise stress echocardiography with simultaneous expired gas analysis for the evaluation of exertional dyspnea were retrospectively identified. After excluding patients with risk factors for PH, participants were categorized into three groups: controls (exercise TRV ≤ 3.2 m/s and exercise E/e' <15; n = 360), isolated exercise-induced increase in TRV (isolated Ei-TRV, exercise TRV > 3.2 m/s and exercise E/e' <15; n = 83), and heart failure with preserved ejection fraction (HFpEF, exercise E/e' ≥15; n = 211).

Peak oxygen consumption was comparable between isolated Ei-TRV and controls, but significantly reduced in HFpEF. Over a median follow-up of 595 days, HFpEF patients had a two-fold higher risk of all-cause death and worsening HF events compared with controls whereas outcomes in isolated Ei-TRV did not significantly differ from controls. Nearly all patients with isolated Ei-TRV exhibited an abnormally elevated mean pulmonary artery pressure/cardiac output slope (mPAP/CO > 3 mmHg/L/min), and those with slopes > 5.2 mmHg/L/min had reduced peak oxygen consumption compared with those with slope ≤ 5.2 mmHg/L/min.

In dyspneic patients without apparent risks for PH, isolated Ei-TRV was associated with preserved exercise capacity, without increased adverse outcomes compared with controls. Assessment of mPAP/CO slope may help refine risk stratification compared to exercise TRV alone in this population.