Background: Optimal gender-specific risk prediction using ECG-gated SPECT left ventricular (LV) volumes and ejection fraction (EF) remains undefined despite reported gender differences in baseline LV function.
Methods: ECG-gated SPECT studies of 891 consecutively referred patients (43% women) were evaluated for LV end-systolic and diastolic volume indices (ESVI, EDVI) and EF. Effects of gender on prediction of hard cardiac events (HCE) and the combined endpoint of all-cause mortality or non-fatal infarction (ACMMI) were evaluated.
Results: Women had smaller ESVI (37 vs 55 mL/m(2)), EDVI (78 vs 99 mL/m(2)), and higher LVEF (56 vs 47%, P < 0.0001 for each) with equivalent rates of HCE (6.1%) and ACMMI (11.8%). HCE risk started at smaller ESVI and EDVI in women compared to men (P < or = 0.05 for each). In women, ESVI 37 mL/m(2) provided maximum HCE prediction compared to 53 mL/m(2) in men. A 1 mL/m(2) increase in ESVI was associated with a 2.9% increased HCE risk in women (P < 0.0001) and a 0.9% increased ACMMI risk in men (P = 0.03). Women with ESVI > 35 mL/m(2) had HCE HR 12.0 compared to women with ESVI < 23 mL/m(2).
Conclusion: LV volume indices and LVEF predict subsequent morbid clinical events in men and women. In women, risk of subsequent events started at smaller LV volume indices compared to men despite similar risk profiles.