Agreement Between Ventricular-Arterial Coupling Measured by Carotid Ultrasound and Transesophageal Echocardiography...

Ventricular-arterial coupling (VAC), defined as the ratio of arterial elastance (E_a) to left ventricular end-systolic elastance (E_es), provides valuable insights for optimizing perioperative hemodynamic management. While transthoracic echocardiography and transesophageal echocardiography (TEE) are used to estimate E_es, both modalities require substantial operator expertise and transthoracic echocardiography may be limited by suboptimal imaging conditions, especially in the perioperative setting. Therefore, the authors propose using carotid ultrasound as a noninvasive and more accessible alternative to estimate VAC. Given its close anatomic and physiological relationship with the proximal aorta, the carotid artery reflects central arterial hemodynamics and may serve as a promising surrogate for VAC. This study aimed to evaluate the agreement between carotid ultrasound and TEE in measuring VAC in patients undergoing cardiac surgery.

Prospective observational pilot study.

Operating room.

Twelve adult patients undergoing elective coronary artery bypass grafting surgery.

Ultrasound measurements were obtained both preoperatively and postoperatively using carotid ultrasound and TEE, and the interchangeability between E_a, E_es, and VAC was evaluated with correlation and Bland-Altman analyses. E_a was calculated using the systolic blood pressure and stroke volume, while E_es was estimated using the single-beat method proposed by Chen et al. MEASUREMENTS AND MAIN RESULTS: Strong correlations were observed between carotid ultrasound and TEE measurements for E_a (r = 0.87; 95% confidence interval [CI], 0.73-0.95), E_es (r = 0.82; 95% CI, 0.63-0.92), and VAC (r = 0.79; 95% CI, 0.56-0.90). The estimation of VAC using carotid ultrasound demonstrated clinically acceptable accuracy and precision, with a bias of -0.01 (95% CI, -0.07 to 0.05) and limits of agreement of ±0.30 (range, -0.18 to 0.39).

Carotid ultrasound-derived VAC demonstrated good correlation with VAC measured using TEE in this pilot study. These preliminary results suggest that carotid ultrasound may be useful for investigating VAC at the bedside, but further studies with larger sample sizes are needed to validate these findings.