Beyond Agreement: a real-world study of the workflow gap between echocardiography and timely structural cardiac assessment How a Validation Study Exposed a Hidden Gap in Cardiac Care

Objectives

To assess agreement between Cardio-HART (CHART) and echocardiography for left ventricular ejection fraction (LVEF) estimation and heart failure (HF) classification in a real-world predominantly ischaemic cohort, while examining whether a point-of-care structural and functional assessment tool could reveal a broader workflow gap between the nominal availability of echocardiography and timely cardiac assessment in routine care.

Design

Prospective single-centre cohort study.

Setting

Secondary-care cardiology service at Cascais Hospital, Lisbon, Portugal.

Participants

Forty-seven adults referred for cardiology evaluation with suspected HF or followed in a hospital HF clinic.

Primary and secondary outcome measures

Agreement between CHART-derived and echocardiographic LVEF by Bland-Altman analysis; diagnostic performance for HF phenotypes; comparison with the Teichholz method.

Results

Mean age was 65.6±15.9 years; 78.7% of participants had HF and 43.2% of HF cases were ischaemic. CHART showed a mean LVEF bias of +1.92% versus echocardiography, with 95% limits of agreement from -14.6% to +18.4% and a mean absolute error of 6.09%. Agreement was strongest in HF with reduced ejection fraction (HFrEF) and HF with mildly reduced ejection fraction (HFmrEF), and lower in HF with preserved ejection fraction (HFpEF). Diagnostic area under the curve for HFrEF classification was 0.89. Compared with the Teichholz method, CHART showed a lower root mean square error relative to Simpson’s biplane LVEF.

Conclusions

CHART showed clinically credible performance for LVEF estimation and HF stratification, particularly in reduced-EF phenotypes. However, the most important finding of this study was not agreement alone. By performing credibly in a cardiology-based real-world setting, CHART exposed a previously under-recognised workflow gap between the nominal availability of echocardiography and timely access to structural cardiac assessment in routine care. The study therefore suggests that the value of CHART lies not only in diagnostic performance, but in making visible, and potentially narrowing, a hidden but consequential gap in cardiac assessment pathways. Larger studies are warranted, particularly for HFpEF and across broader clinical workflows.

Strengths and limitations of this study

• This was a prospective real-world study conducted in a cardiology-led secondary-care setting.

• CHART was evaluated against same-day echocardiography in almost all participants, using Simpson’s biplane LVEF as the reference standard.

• The study contributes not only agreement data, but also operational insight into the gap between the assumed presence of echocardiography and its timely use in real clinical workflows.

• The sample size was small, limiting precision and subgroup interpretation.

• HFpEF findings should be regarded as exploratory and require confirmation in larger multicentre cohorts.