The NEW ENGLAND JOURNAL O MEDICINE Table 2.Primary and Secondary Effectiveness and Safety End Points. End Point 6 PValue Length of ospital stay-h 232470 Median Time to diagnosis-hr a s with final diagnosis other than acute coronary syndrome s with final diagnosis of acute coronary syndrome Interquartile range Discharge status一 1o.(% harge from emergency department against medical advice 器 up for recurrent chest pain within 28 days-no Repeat visit to emergency departmen 4 19 0.38 ry syndrome rocedural compli Major adverse cardiova ular events at dayso. 8 Plus-minus values are meansSD. CCTA and after standard evaluation in the emer- acute coronary syndr the mean time to diag gency departm s was sig all cohor groups sis o group wer ctly dis 304 N ENGLJ MED 367:4 NEJM.ORG JULY 26,2012 T h e n e w e ngl a nd j o u r na l o f m e dic i n e 304 n engl j med 367;4 nejm.org july 26, 2012 CCTA and after standard evaluation in the emer￾gency department. In the overall cohort and also in the sub￾groups with or without a final diagnosis of an acute coronary syndrome, the mean time to diag￾nosis was significantly decreased with CCTA as compared with a standard evaluation. Patients in the CCTA group were more often directly dis￾Table 2. Primary and Secondary Effectiveness and Safety End Points.* End Point CCTA (N=501) Standard Evaluation (N=499) P Value Length of hospital stay — hr All patients in intention-to-treat analysis <0.001 Mean 23.2±37.0 30.8±28.0 Median 8.6 26.7 Interquartile range 6.4–27.6 21.4–30.6 Patients with final diagnosis other than acute coronary syndrome <0.001 Mean 17.2±24.6 27.2±19.5 Median 8.1 26.3 Interquartile range 6.2–24.6 20.6–29.5 Patients with final diagnosis of acute coronary syndrome 0.87 Mean 86.3±72.3 83.8±61.3 Median 56.9 71.8 Interquartile range 46.2–95.9 45.2–96.7 Time to diagnosis — hr All patients in intention-to-treat analysis <0.001 Mean 10.4±12.6 18.7±11.8 Median 5.8 21.0 Interquartile range 4.0–9.0 8.5–23.8 Patients with final diagnosis other than acute coronary syndrome <0.001 Mean 10.6±12.3 18.8±12.0 Median 6.1 21.1 Interquartile range 4.0–9.6 8.7–23.8 Patients with final diagnosis of acute coronary syndrome 0.002 Mean 8.0±15.1 17.1±9.5 Median 4.4 14.9 Interquartile range 3.3–5.6 7.4–25.1 Discharge status — no. (%) <0.001 Direct discharge from emergency department 233 (47) 62 (12) Admission to observation unit 153 (30) 301 (60) Admission to hospital 107 (21) 125 (25) Left against medical advice 8 (2) 11 (2) Follow-up for recurrent chest pain within 28 days — no. Repeat visit to emergency department 14 19 0.38 Repeat hospitalization 7 7 Safety — no. Undetected acute coronary syndrome 0 0 Periprocedural complications 2 0 0.50 Major adverse cardiovascular events at 28 days — no. 2 6 0.18 * Plus–minus values are means ±SD