Sotatercept lowered RV contractility in step with afterload while strain improved

Design

Prospective single-arm study with invasive exercise haemodynamics

Population

30 adults with pulmonary arterial hypertension, before and after 24 weeks of sotatercept

Primary outcome

RV contractility, afterload, RV–PA coupling and right heart strain

Effect

Coupling preserved (+0.08, −0.11 to +0.26); RV free-wall strain +6.2% (4.5–7.8)

A prospective study in Circulation (22 September) measured right heart mechanics with simultaneous echocardiography and invasive pressures, at rest and on exercise, before and after 24 weeks of sotatercept in 30 adults with pulmonary arterial hypertension.

Sotatercept lowered pulmonary arterial elastance, the measure of afterload, and right ventricular contractility fell in proportion (correlation r = 0.70), so coupling between the ventricle and the pulmonary circulation was preserved. TAPSE and tricuspid annular velocity fell. Yet free-wall strain rose by about 6 percentage points, fractional area change improved, and right atrial filling and contraction got better at rest and on exercise.

The practical point is for anyone reading serial echoes. On sotatercept, a lower TAPSE may reflect a ventricle that no longer needs to work as hard and has shifted from longitudinal annular motion to free-wall shortening, not a failing ventricle. Judge the right heart on free-wall strain, fractional area change and the clinical picture together.

• A falling TAPSE on sotatercept may reflect lower afterload rather than right ventricular decline.
• Track RV free-wall strain and fractional area change on serial echoes in patients on sotatercept.
• Read right heart indices alongside symptoms, walk distance and natriuretic peptides.
• These are mechanistic data from 30 patients, not outcome evidence.

Why it matters

A familiar echo marker can move in the wrong direction on a drug that is helping, and prompt the wrong conclusion.

Don't overread it

This small uncontrolled study explains physiology; it does not add outcome evidence for sotatercept.

The statistics, in plain English

The coupling ratio changed by +0.08 with an interval from −0.11 to +0.26, which crosses zero — meaning no meaningful change, which is the reassuring result here. With 30 participants and no control group, these are measurements of what changed, not proof of benefit.

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