Myocardial size and fibrosis changes during left ventricular assist device support

Area of Science:

• Cardiology
• Biomedical Engineering
• Pathology

Background:

• Left ventricular assist device (LVAD) implantation is known to decrease left ventricular (LV) myocyte size and reduce fibrosis.
• Understanding LV functional recovery and its predictors after LVAD implantation is crucial for patient outcomes.

Purpose of the Study:

• To evaluate left ventricular (LV) functional recovery following LVAD implantation.
• To identify predictive factors for LV functional recovery, including preoperative histological findings.

Main Methods:

• Six patients with idiopathic cardiomyopathy received LVAD support using an EVAHEART system for an average of 2.91 years.
• Histologic LV apex samples were analyzed. Brain natriuretic peptide (BNP) and echocardiographic parameters were assessed at 1 and 24 months post-implantation.

Main Results:

• LVAD implantation improved BNP levels, LV dimensions, fractional shortening (FS), and right ventricular systolic pressure (RVSP).
• Preoperative fibrosis correlated with longer heart failure history and higher pulmonary artery pressures. Hypertrophic myocytes were associated with lower preoperative FS.
• A correlation was found between fibrosis amount and the rate of BNP change post-LVAD. Less preoperative fibrosis and smaller myocytes predicted better LV function improvement.

Conclusions:

• LVAD support leads to significant improvements in LV function and associated biomarkers.
• Preoperative myocardial fibrosis and myocyte size are important histological predictors of LV functional recovery after LVAD implantation.