Abstract 2607: Enhanced Prognostic Utility of Exercise Treadmill Test in Women With Chest Pain: Role of Non-Electrocardiographic Exercise Variables
OBJECTIVE: Limited diagnostic accuracy of the exercise treadmill test (ETT) has led to advocacy of more costly stress imaging as the initial test for women with chest pain. We hypothesized that ETT variables could enhance the utility of ETT for assessing CAD risk in properly selected women.
METHODS: We reviewed ETT in all women referred for chest pain from 9/96 to 10/03. Exclusions: known cardiac disease or abnormal baseline ECG. Multiple ETT variables were related to long-term mortality obtained from the Social Security Death Index.
RESULTS: ETT were analyzed in 1,974 women (mean age 53 yr, 21– 86). Diagnostic ETT (≥85% of predicted maximum HR) were achieved in 94% (1857/1974): Negative (neg) 77% (1525/1974); positive (pos) for ischemia (>1.0mm ST↓) 17% (332/1074); nondiagnostic (nondx) 6% (117/1974). During a mean follow-up of 5.2 yr (2.4 –9.5), mortality in neg = 1.6%, in pos = 1.2%, in nondx = 6.0% (p<0.002 vs. pos and neg groups). Compared to the neg and pos groups, ETT in nondx women were characterized by significantly impaired METS, peak double product (HR x SBP), and chronotropic index (Chrono. Index=HR reserve on ETT) (table⇓).
CONCLUSIONS: These results in women evaluated for chest pain indicate:
a large majority of properly selected women attained diagnostic ETT;
ischemic ST ↓ did not predict mortality;
nondx ETT, characterized by variables related to reduced functional capacity, was associated with increased long-term risk.
Thus, analysis of ETT variables can enhance the utility of ETT and reduce the need for more costly testing.