Does repair of mitral regurgitation eliminate the need for left ventricular volume reduction?

Associations between Left Ventricular Cavity Size and Cardiac Function and Overload Determined by Natriuretic Peptide Levels and a Covariance Structure Analysis

The effects of left ventricular (LV) cavity size on cardiac function and overload have not yet been fully elucidated. We performed a covariance structure analysis and drew theoretical path models to clarify the effects of hemodynamic parameters on the stroke volume index (SVI) as a marker of cardiac function and on the plasma B-type natriuretic peptide (BNP) level as a marker of cardiac overload. We simultaneously measured various hemodynamic parameters and the BNP levels during cardiac catheterization in 1,715 inpatients of our institution. The current path models tested the validity of the Frank-Starling law in patients with heart failure using the SVI, the LV end-systolic volume index (LVESVI) and the LV end-diastolic volume index (LVEDVI). Using the BNP levels, the path models clearly demonstrated that LVESVI substantially augmented cardiac overload, whereas LVEDVI palliated this parameter. These volume indices exerted opposite effects on cardiac function and overload. These results advance the understanding of the relationships between LV cavity size and both cardiac function and overload and indicate the increasing importance of LV diastolic volume in heart failure and the utility of LVESVI as an important marker of cardiac remodeling for further relevant studies.

Ventricular volume reduction procedures

Although partial left ventriculectomy (PLV) has been abandoned in many institutions, a few hospitals continue to perform it with a relatively favorable outcome. Other volume reduction procedures have become popular with renewed interest in ventricular reshaping to improve function. Although recent refined selection criteria have improved survival with PLV, earlier unpredictable results prompted less invasive procedures based on the same physiologic concept of reducing radius or wall tension by wrapping, piercing, or clasping. These new techniques are not only less invasive but also reversible and adjustable and appear safer for less symptomatic patients at risk of progressive heart failure. Nonetheless, mechanisms of action and degrees of volume reduction and/or restriction need to be delineated before widespread clinical application.