Small Heart Size and Premature Death in 366,484 Individuals With Normal Ejection Fraction

Area of Science:

• Cardiology
• Echocardiography
• Public Health

Background:

• Preserved left ventricular ejection fraction (LVEF) is common in many cardiac conditions.
• Small ventricular size in preserved LVEF has been linked to reduced functional capacity.
• The impact of small ventricular size on clinical outcomes in preserved LVEF remains unclear.

Purpose of the Study:

• To investigate the association between small heart size and premature mortality.
• To analyze a large, multicenter adult patient cohort using transthoracic echocardiography.
• To determine the relationship between left ventricular end-diastolic volume (LVEDV) and 5-year mortality.

Main Methods:

• Analysis of 366,484 individuals with LVEF ≥50% (including 279,442 with LVEF ≥60%).
• Stratification by sex and quartiles of LV end-diastolic volume (LVEDV), indexed LVEDV (LVEDVi), and LV end-diastolic diameter.
• Mortality assessment via linkage with the National Death Index over approximately 2 million person-years.

Main Results:

• Smallest cardiac size quartiles were associated with higher 5-year all-cause mortality, even after age adjustment.
• The smallest LVEDVi quartile showed a 14-18% increased odds of 5-year all-cause mortality, with greater effect in high-normal LVEF.
• A U-shaped relationship was observed between LV chamber size and all-cause mortality; females with smallest LVEDVi had higher cardiovascular mortality, especially with LVEF ≥60%.

Conclusions:

• Small ventricular size is associated with increased mortality in individuals with normal LVEF.
• The increased mortality risk is particularly significant for females and those with higher LVEF.
• Findings highlight the prognostic importance of ventricular size in preserved LVEF.