Transesophageal Echocardiographic Assessment of Pulmonary Artery-to-Ascending Aorta Ratio for the Detection of Pulmonary Hypertension in Cardiac Surgical Patients

Abstract

Objective: The objective of the study was to investigate if the main pulmonary artery (mPA)-to-ascending aorta (AscAo), (mPA:AscAo) ratio could serve as a screening tool in identifying pulmonary artery hypertension (PAH).

Design: A prospective observational study.

Setting: Tertiary care center, university hospital.

Participants: Fifty-four adult patients undergoing off-pump coronary artery bypass grafting surgery (OPCAB).

Interventions: mPA and AscAo transverse diameters were measured by transesophageal echocardiography (TEE) and the mean pulmonary arterial pressures (mPAP) were recorded simultaneously using a pulmonary artery catheter.

Measurements and main results: mPA:AscAo ratio demonstrated significant linear correlation with mPAP measured by pulmonary artery catheterization (ie, r = 0.61, confidence interval [CI] = 0.5352-0.6736, p < 0.0001). Receiver operating characteristic curves were performed to evaluate sensitivity and specificity of mPA:AscAo ratio ≥1 for diagnosing PAH (mPAP ≥25 mmHg). Area under the curve for mPA:AscAo ratio was 0.91 (95% CI, 0.869-0.936, p < 0.0001), with a sensitivity of 84.27%, specificity of 83.92%, positive-predictive value of 87.6% and negative-predictive value of 81.1% for a mPAP ≥25 mmHg.

Conclusions: The ratio of mPA:AscAo is a simple, reliable, and reproducible method that can be obtained through TEE, which guides the clinician to screen patients with PAH.

Keywords: OPCAB; TEE; mPA:AscAo ratio; mPAP; pulmonary arterial hypertension; pulmonary artery catheterization.