Prolonged Elevation of Tricuspid Regurgitation Pressure Gradient After Exercise in Patients With Exercise-induced Pulmonary Hypertension

Abstract

It is necessary to measure the peak tricuspid regurgitation pressure gradient (TRPG) that is recorded at maximum exercise intensity when diagnosing exercise-induced pulmonary hypertension (ePH) on exercise stress echocardiography (ESE). However, it is difficult to measure maximum TRPG during the treadmill exercise. If ePH induced TRPG elevation continues during recovery period after exercise termination, this elevation will serve as a practical diagnostic standard. We aimed to assess whether the elevation of postexercise peak TRPG prolong soon after finishing exercise in patients with ePH. Seventy-four patients underwent symptom-limited ESE by using a semirecumbent bicycle ergometer. ePH was defined as peak TRPG > 50 mm Hg at maximum exercise. We measured peak TRPG during exercise and until 5 minutes afterward. Thirty-five patients were diagnosed with ePH; their median TRPG was 57 mm Hg [interquartile range: 52-62 mm Hg] at maximum exercise. Peak TRPG in patients with ePH was > 40 mm Hg until 2 minutes after exercise. The cut-off values of peak TRPG to detect ePH were 43 mm Hg just after exercise and 41 mm Hg at 1 minute afterward (areas under the curve: 0.98, 0.92, respectively; both p < 0.001). In conclusion, elevated peak TRPG persisted for at least 2 minutes after finishing exercise, and this time frame will therefore provide a new window for diagnosing ePH by ESE.