Myocardial constructive work and cardiac mortality in resynchronization therapy candidates

Area of Science:

• Cardiology
• Echocardiography
• Heart Failure Management

Background:

• Cardiac resynchronization therapy (CRT) is used for heart failure patients.
• Myocardial constructive work (CW) assessed by pressure-strain loops (PSLs) is a potential predictor of CRT response.
• Evaluating CW's role in predicting cardiac outcomes in CRT patients is crucial.

Purpose of the Study:

• To assess the predictive value of myocardial constructive work (CW) for cardiac outcomes in heart failure patients undergoing CRT.
• To determine if CW can identify patients at high risk of cardiac death after CRT.

Main Methods:

• Retrospective study of 166 CRT candidates with ejection fraction ≤35% and QRS duration ≥120 ms.
• Echocardiography (2D and speckle-tracking) and PSLs used to assess myocardial CW before and after CRT.
• Median follow-up of 4 years to record cardiac death and volumetric response.

Main Results:

• CW ≤888 mm Hg% was the sole independent predictor of cardiac mortality (HR 4.23, P = .03) in multivariable analysis.
• 71% of patients showed a volumetric response to CRT (≥15% reduction in LV end-systolic volume).
• Among CRT responders, CW ≤888 mm Hg% identified a high-risk subgroup for cardiac death (P = .04), significantly improving prediction models.

Conclusions:

• Left ventricular CW estimation using PSLs is a novel tool for predicting cardiac outcomes in CRT candidates.
• CW assessment can refine risk stratification and personalize CRT management.
• Incorporating CW into predictive models enhances the accuracy of identifying patients at risk for adverse cardiac events.