What is the clinical evidence from this study?

Study design: Cohort. Population: Elective non-cardiac surgery (n=405). Intervention: Ea/Ees ratio > 1 (Impaired ventriculo-arterial coupling) vs. Ea/Ees ratio ≤ 1. Primary outcome: Post-induction hypotension (MAP < 65 mmHg) (OR 2.95, 95% CI 1.08-8.03, p=0.034).

What question did this study set out to answer?

This study aims to evaluate how well ventriculo-arterial coupling and echocardiographic metrics predict hypotension following anaesthesia induction.

April 22, 2026Open Access

Predictive value of ventriculo-arterial coupling for hypotension after induction of anaesthesia: a prospective observational cohort study

Q: What are the key findings of this study?

An Ea/Ees ratio > 1 was independently associated with an increased risk of post-induction hypotension (OR 2.95) in adults undergoing elective non-cardiac surgery.

Q: What does this research mean for the field?

An impaired ventriculo-arterial coupling index (Ea/Ees ratio > 1) is independently associated with an increased risk of post-induction hypotension in adults undergoing elective non-cardiac surgery, and its inclusion improves risk reclassification. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Key Result

An Ea/Ees ratio > 1 was independently associated with an increased risk of post-induction hypotension (OR 2.95) in adults undergoing elective non-cardiac surgery.

Key Points

This study aims to evaluate how well ventriculo-arterial coupling and echocardiographic metrics predict hypotension following anaesthesia induction.
Conducted a prospective observational cohort study with patients undergoing elective non-cardiac surgery.
Used transthoracic echocardiography to derive the ventriculo-arterial coupling index and assessed mean arterial pressure.
Applied a generalised additive model for predictor analysis and evaluated prognostic value through FNI and AUC changes.
Post-induction hypotension occurred in 39.8% of patients.
An E_a/E_es ratio greater than 1 was associated with an odds ratio of 2.95 for developing hypotension.
Incorporating echocardiographic parameters improved the AUC to 0.768, while adding VAC variables further raised it to 0.785.

Study Design

Type

Cohort (n=405)

Multicenter

Structured PICO

Does pre-operative assessment of ventriculo-arterial coupling (Ea/Ees ratio) improve prediction of post-induction hypotension in adults undergoing elective non-cardiac surgery?

Population

405 hemodynamically stable adults (≥18 years) scheduled for elective non-cardiac, non-obstetric, and non-gynaecologic surgery under general anaesthesia with endotracheal intubation. Median age 57, 58% female, Vietnam-based. Key exclusions: uncorrected congenital heart disease, moderate-to-severe valvular disease or pulmonary hypertension, arrhythmias, anticipated difficult airway, and known allergies to anaesthetic agents.

Intervention

Pre-operative assessment of ventriculo-arterial coupling (VAC) using transthoracic echocardiography and non-invasive blood pressure to derive the Ea/Ees ratio

Comparator

Standard clinical prediction model with or without conventional echocardiographic parameters

Outcome

Post-induction hypotension (PIH), defined as the first occurrence of mean arterial pressure < 65 mmHg between anaesthesia induction and surgical incisionsurrogate

Pre-operative echocardiographic assessment of ventriculo-arterial coupling, specifically an Ea/Ees ratio > 1, independently predicts post-induction hypotension and improves risk reclassification beyond standard clinical and echocardiographic models.

Main Result

Effect estimate: OR 2.95 (95% CI 1.08-8.03)

p-value: p=0.034

Limitations

Pre-operative echocardiography performed within 48 h may not fully reflect haemodynamics at induction.
The number of candidate predictors was large relative to the sample size, potentially introducing bias in performance estimates.
Single-centre cohort with largely normal echocardiographic findings limits generalisability.
PIH was defined by an absolute MAP threshold, potentially making higher baseline MAP appear protective due to a threshold effect.
Non-invasive blood pressure measured every 2 min may miss brief hypotension and limit the assessment of hypotension duration or burden.

Abstract

Abstract Background Post-induction hypotension (PIH) is associated with acute perioperative organ injury. We quantified the added value of echocardiographic parameters and ventriculo-arterial coupling (VAC)-related variables for the prediction of PIH. Methods A prospective observational cohort study conducted between July 2023 and November 2024 enrolled adults undergoing elective non-cardiac surgery. The ventriculo-arterial coupling index ( E a / E es ) was derived pre-operatively using transthoracic echocardiography combined with non-invasive blood pressure measurements. PIH was defined as the first occurrence of mean arterial pressure 1 was associated with PIH (OR 2.95; 95% CI 1.08–8.03; p = 0.034). The clinical model showed an AUC of 0.720 (95% CI 0.669–0.771). The addition of echocardiographic parameters increased the AUC to 0.768 (95% CI 0.720–0.816; Holm-adjusted p = 0.018) and provided 37% FNI (Holm-adjusted p = 0.199). The incorporation of VAC-related variables further increased the AUC to 0.785 (95% CI 0.739–0.831; Holm-adjusted p = 0.002) and yielded 46% FNI (Holm-adjusted p = 0.030). Compared with the clinical–echocardiographic model, incorporation of VAC-related variables provided an additional 14% FNI (Holm-adjusted p = 0.018) without a statistically significant AUC increase (0.017; 95% CI −0.004–0.039; Holm-adjusted p = 0.199). Conclusion PIH was common and was independently associated with impaired VAC, as reflected by an E a / E es ratio > 1. Incorporation of echocardiographic parameters improved the discriminatory performance of a clinical prediction model, and the further addition of VAC-related variables provided meaningful improvement in risk reclassification, despite only modest gains in overall discrimination.

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