Right ventricular-pulmonary artery coupling in cardiac resynchronization therapy: evolution and prognosis

Area of Science:

• Cardiology
• Heart Failure Research
• Echocardiography

Background:

• Chronic pressure overload and right ventricular (RV) dysfunction can cause RV-pulmonary artery (PA) uncoupling in heart failure patients.
• The prognostic value of RV-PA coupling, assessed by echocardiography, in patients receiving cardiac resynchronization therapy (CRT) requires further investigation.

Purpose of the Study:

• To evaluate the evolution and prognostic significance of the tricuspid annular plane systolic excursion (TAPSE)/pulmonary artery systolic pressure (PASP) ratio in patients undergoing CRT.

Main Methods:

• Non-invasive echocardiography was used to measure the TAPSE/PASP ratio at baseline and 6-month follow-up in 807 CRT recipients.
• A TAPSE/PASP ratio below 0.45 mm/mmHg was defined as RV-PA uncoupling.
• The primary endpoint was all-cause mortality, with a median follow-up of 97 months.

Main Results:

• Patients with a baseline TAPSE/PASP ratio <0.45 mm/mmHg had significantly lower 3- and 5-year survival rates (76% and 58%) compared to those with a ratio ≥0.45 mm/mmHg (91% and 82%).
• A baseline TAPSE/PASP ratio <0.45 mm/mmHg was an independent predictor of all-cause mortality (HR 1.437, P=0.002).
• Lack of improvement in the TAPSE/PASP ratio after CRT implantation was also independently associated with worse survival.

Conclusions:

• The baseline TAPSE/PASP ratio is an independent predictor of long-term outcomes in CRT recipients, offering incremental value over TAPSE alone.
• A low baseline TAPSE/PASP ratio and a failure to improve this ratio post-CRT are associated with increased mortality.
• Echocardiographic assessment of RV-PA coupling provides crucial prognostic information in CRT patients.