Background: Limited data exist on the prevalence, associations, and prognosis of individuals with asymptomatic left ventricular systolic dysfunction (ALVSD), especially in populations without previous clinical cardiovascular disease (CVD).
Methods and results: Kaplan-Meier and Cox proportional hazard analyses were used to assess the association between ALVSD, defined as left ventricular ejection fraction <50%, and adjudicated incident congestive heart failure (CHF), all-cause mortality, and CVD events. Of 5004 participants, 112 participants had CHF, 321 had a CVD event, and 278 died after 9 years of follow-up. The overall prevalence of ALVSD was 1.7%, with a higher prevalence in blacks (2.6%). ALVSD had a worse cardiovascular risk profile and was also associated with increased risk in unadjusted and adjusted models for incident CHF (HR [hazard ratio] [95% CI {confidence interval}]: 12.0 [7.04-20.3], P<0.0001 and 8.69 [4.89-15.45], P<0.001 respectively), CVD (HR [95% CI]: 3.32 [1.98-5.58], P<0.001 and 2.21 [1.30-3.73], P=0.003 respectively), and all-cause mortality (HR [95% CI]: 3.47 [2.03-5.94], P<0.0001 and 2.00 [1.13-3.54], P=0.017, respectively). A 10% decrement in left ventricular ejection fraction at baseline was associated with an increase in risk in unadjusted and adjusted models for clinical CHF (HR [95% CI]: 2.17 [1.82-2.63], P<0.0001 and 2.13 [1.73-2.51], P<0.001, respectively) and all-cause mortality (HR [95% CI]: 1.22 [1.05-1.41], P=0.009 and 1.17 [1.00-1.36], P=0.047, respectively). Among the subset of participants with ALVSD, the left ventricular mass index was particularly informative about risk for incident CHF (c-index=0.74).
Conclusions: ALVSD is uncommon in individuals without previous clinical CVD, but it is associated with high risk for CHF, CVD, and all-cause mortality. The left ventricular mass index had good discrimination for incident CHF in Multi-Ethnic Study of Atherosclerosis (MESA) participants with ALVSD.