Quantitative Assessment of Myocardial Work Index (MWI) as a Predictor of Early Response to SGLT2 Inhibitors in Heart Failure

Abstract

Background and Purpose: The rapid adoption of SGLT2 inhibitors (SGLT2i) in Heart Failure (HF) management necessitates precise, early imaging biomarkers to predict therapeutic response. Current methods relying on ejection fraction are often delayed and insensitive to immediate myocardial changes. Myocardial Work Index (MWI), derived from non-invasive pressure-strain loops, offers a sensitive, quantitative measure of cardiac energy efficiency, potentially identifying early responders to SGLT2i-associated myocardial benefit.

Methods: A prospective cohort study enrolled 210 HFrEF patients initiating SGLT2i therapy. All participants underwent comprehensive echocardiography, including assessment of MWI and Global Longitudinal Strain (GLS), at baseline and 90 days. Early positive response was defined as a composite endpoint: reduction in NT-proBNP >30% and improvement in NYHA class at 90 days. A multivariate logistic regression analysis was performed to determine the independent predictive capacity of baseline MWI for the primary endpoint.  

Results: At 90 days, 137 patients (65%) were classified as early responders. Baseline MWI was significantly lower in non-responders compared to responders (1250 mmHg% vs. 1580 mmHg%; p<0.001). The multivariate logistic regression confirmed that a baseline MWI threshold of <1300 mmHg% was the single strongest independent predictor of non-response (Adjusted Odds Ratio: 4.10; 95% CI: 2.85-5.90; p<0.001). This threshold demonstrated 85% sensitivity and 82% specificity for identifying therapeutic failure. In contrast, baseline LVEF was not predictive (p=0.45). This precise imaging metric allows for timely adjustment of Guideline-Directed Medical Therapy (GDMT).

Conclusion: Baseline Myocardial Work Index, obtained non-invasively, offers a powerful, early predictive biomarker for SGLT2i therapeutic response in HFrEF. This quantitative imaging strategy enables personalized pharmacological management and resource optimization, supporting the regional mandate for utilizing advanced diagnostic innovation to drive high-quality outcomes in cardiovascular health.