Does an imaging stress-test adds information to prognostic scores in patients with chest pain in the emergency department?

We evaluated the ability of a stress-test (Str-T) to improve the risk stratification based on prognostic scores in patients presenting to the ED with chest pain. Between 2008, June and 2013, December, 1082 patients with chest pain were evaluated with an imaging Str-T. With a retrospective analysis, patients were stratified according to: (1) Florence Prediction Rule as low (0-1, LR-FPR), intermediate (2-4, IR-FPR), high risk (5-6, HR-FPR), respectively, 26, 50 and 24% of patients; (2) HEART score as LR-HEART, (0-3) and HR-HEART (>/=4), respectively, 36 and 64%; (3) likelihood of CAD according to NICE guidelines, 10-29% LR-NICE, 30-60% IR-NICE and > 60% HR-NICE, respectively, 12, 18 and 70%. Scores' diagnostic performance was calculated with Str-T as reference. One-month follow-up by a phone call was performed, to investigate the occurrence of new cardiovascular events. In LR and HR patients, FPR and NICE score showed sensitivity 66 vs 93%, specificity 59 vs 19% (both p < 0.001), Positive Predictive Value (PPV) 36 vs 31%, Negative Predictive Value (NPV) 83 vs 87%. Among LR-HEART patients, Str-T was positive for inducible ischemia in 53 (14%) patients and 12 (4%) of them underwent a percutaneous coronary revascularization. The Str-T was negative for inducible ischemia in 760 (70%) patients, positive in 272 (25%), inconclusive in 50 (5%); among patients in the LR and IR subgroups, incidence of CAD (1.3 and 1.6%) and the cumulative incidence of significant events at 1-month follow-up (both 1%) was very low Str-T improved prognostic scores' diagnostic performance in LR- and HR-subgroups.