RV-pulmonary artery uncoupling predicts PH in heart failure patients
TAPSE/PASP and TAS'/PASP ratios differed among people with HFpEF
Echocardiogram (ECG) measures that indicate the heart’s right ventricle (RV) and the pulmonary arteries are working poorly together to send blood to the lungs may help predict the presence of pulmonary hypertension (PH) in people with a certain type of heart failure, a recent publication indicates.
Called TAPSE/PASP and TAS’/PASP ratios, these indicators of RV-pulmonary artery uncoupling differed between heart failure with preserved ejection fraction (HFpEF) patients who were or were not diagnosed with PH. They also correlated with indicators of PH collected using a more invasive technique.
“The article … reinforces the importance of diagnosing PH in HFpEF and emphasizes the role of mild TAPSE/PASP and TAS’/PASP impairment in the early identification of PH in this subgroup of patients,” a group of scientists noted in a commentary that accompanied “Right Ventricular‐Vascular Uncoupling Predicts Pulmonary Hypertension in Clinically Diagnosed Heart Failure With Preserved Ejection Fraction,” which was published in the Journal of the American Heart Association.
Normally, the RV pumps deoxygenated blood through the pulmonary arteries to the lungs where it picks up oxygen and is sent out to the rest of the body via the left ventricle.
In HFpEF, the most common type of heart failure, an increased pressure while the left ventricle fills with oxygenated blood can drive increased blood pressure in the pulmonary arteries, the hallmark of PH. Sometimes, the RV may struggle to cope with this and becomes dysfunctional.
PH is thus prevalent in HFpEF patients and, particularly when coupled with RV dysfunction, is associated with a worse prognosis. For this reason it’s important to identify PH in heart failure early on using noninvasive techniques to implement appropriate interventions.
Predicting a PH diagnosis
To that end, scientists in Taiwan explored which measures on a routine ECG might predict PH in HFpEF patients. ECG is a noninvasive technique that uses sound waves to generate a moving image of the heart.
The analysis involved 113 HFpEF patients who underwent ECG as well as right heart catheterization (RHC), an invasive technique for diagnosing PH, at the scientists’ clinic. Ultimately, 68 were diagnosed with PH, marked by increased pulmonary artery pressure during RHC. Of the 45 without PH at rest, 16 presented with exercise-induced PH.
Patients with resting PH were found to have significantly lower TAPSE/PASP and TAS’/PASP ratios on ECG than those without PH, both at rest and during exercise. Tricuspid annular plane systolic excursion, or TAPSE, is a measure of RV function, as is TAS’, or tricuspid annular systolic velocity. PASP stands for pulmonary artery systolic pressure and is a proxy of blood pressure in the pulmonary arteries.
The ratio between TAPSE/TAS’ and PASP reflects how well the RV and pulmonary arteries are working together to deliver blood to the lungs. A lower ratio indicates they have uncoupled and the RV is not effectively delivering blood through the pulmonary arteries.
Lower TAPSE/PASP and TAS’/PASP ratios strongly correlated with higher pulmonary artery pressure measured via RHC at both rest and during exercise, statistical analyses indicated. They also correlated with pulmonary capillary wedge pressure (PCWP), which reflects the pressure during left ventricle filling that’s used to diagnose certain types of PH.
Final statistical analyses indicated a lower TAPSE/PASP ratio on ECG was a significant predictor of higher pulmonary artery pressure and PCWP during exercise. Additional analyses confirmed the ability for TAPSE/PASP and TAS’/PASP to predict PH: they could accurately distinguish PH with around 75% accuracy when measured at rest.
Altogether, the findings suggest signs of RV-pulmonary artery uncoupling on ECG can help detect PH in heart failure patients.
“Patients with HFpEF exhibiting abnormal TAPSE/PASP and TAS’/PASP ratios require appropriate diagnostic testing to guide their treatment in the context of HFpEF,” the researchers said.