Why Clinicians Should Care About the Cardiac Interstitium

Area of Science:

• Cardiology
• Pathophysiology
• Biomedical Engineering

Background:

• Interstitial heart disease, including myocardial fibrosis and cardiac amyloidosis, is a significant cause of heart failure, morbidity, and mortality.
• These conditions involve excess protein accumulation in the cardiac interstitium, leading to architectural distortion and impaired function.
• Myocardial fibrosis is common and causes symptoms like heart failure and arrhythmia, while cardiac amyloidosis is rarer but more severe.

Purpose of the Study:

• To advance the understanding of interstitial heart disease pathophysiology.
• To highlight the role of the cardiac interstitium in heart failure.
• To explore novel therapeutic targets by dichotomizing myocardial phenotypes.

Main Methods:

• Utilized myocardial extracellular volume measurements to assess interstitial expansion.
• Analyzed the distinct characteristics of myocardial fibrosis and cardiac amyloidosis.
• Proposed a conceptual framework of myocardium as interstitial and cardiomyocyte phenotypes.

Main Results:

• Interstitial heart disease is fundamentally linked to interstitial protein accumulation and architectural changes.
• Myocardial extracellular volume is a critical metric for understanding interstitial heart disease.
• Dichotomizing the myocardium offers new insights into heart failure mechanisms.

Conclusions:

• A deeper understanding of the cardiac interstitium is crucial for addressing heart failure.
• Recognizing myocardial fibrosis and cardiac amyloidosis as distinct entities within interstitial heart disease is important.
• This research may pave the way for more effective heart failure therapies by targeting interstitial and cardiomyocyte pathways.