IMproving PULmonary hypertension Screening by Echocardiography: IMPULSE.

Area of Science:

• Cardiology
• Pulmonary Medicine
• Diagnostic Imaging

Background:

• Pulmonary hypertension (PH) is defined by mean pulmonary artery pressure (mPAP) > 20 mmHg via right heart catheterisation (RHC).
• Transthoracic echocardiography (TTE) is a screening tool for suspected PH.
• International guidelines recommend multi-parameter TTE assessment for PH probability, but real-world effectiveness is unproven.

Purpose of the Study:

• To assess the accuracy of European Society of Cardiology (ESC) and British Society of Echocardiography (BSE) TTE probability algorithms for PH detection in a UK PH center.
• To identify echocardiographic markers and revise algorithms for improved PH detection in patients with low/intermediate TTE PH probability.

Main Methods:

• TTE followed by RHC (within 4 months) in patients with suspected PH.
• Calculation of BSE/ESC PH TTE probabilities and additional right ventricular (RV) function markers (longitudinal, radial, diastolic).
• Development and evaluation of a refined IMPULSE algorithm for patients with low/intermediate TTE PH probability.

Main Results:

• Of 310 patients, 236 (76%) had RHC-confirmed PH. BSE/ESC TTE sensitivity was 89%, specificity 68%.
• 36% of low-probability patients had confirmed PH; RV free wall longitudinal strain (RVFWLS) differentiated PH presence (P < 0.02).
• The IMPULSE algorithm, incorporating RVFWLS, RV fractional area change (RVFAC), and isovolumic relaxation time (IVRT), reduced false negatives by 29% in low-probability cases, showing high specificity and PPV.

Conclusions:

• Current TTE PH probability guidelines lack sensitivity for milder PH forms.
• Combining TTE markers of RV radial, longitudinal, and diastolic function enhances identification of milder PH, especially in low-probability cases.