Table 2.

Performance of Various CT Strategies for Diagnosis of ACS: CAC>0, Optimal cutpoint CAC ≥22, CCTA and Selective CCTA using 50% and 70% Stenosis Thresholds

	Sensitivity (95% CI)	Specificity (95% CI)	PPV (95% CI)	NPV (95% CI)	Accuracy (95% CI)
CAC Scan alone
CAC score >0	36/38 95% (82–99%)	251/435 58% (53–62%)	36/220 16% (12–22%)	251/253 99% (97–99.9%)	287/473 61% (56–65%)
CAC score≥22	34/38 89% (75–97%)	314/435 72% (68–76%)	34/155 22% (16–29%)	314/318 99% (97–99.7%)	348/473 74% (69–77%)
CCTA using 50% Stenosis Threshold
CCTA	36/38 95% (82–99%)	389/435 89% (86–92%)	36/82 44% (33–55%)	389/391 99% (98–99.9%)	425/473 90% (87–92%)
CAC > 0, then Selective CCTA	35/38 92% (79–98%)	391/435 90% (87–93%)	35/79 44% (33–56%)	391/394 99% (98–99.8%)	426/473 90% (87–93%)
CAC ≥22, then Selective CCTA	33/38 87% (72–96%)	399/435 92% (89–94%)	33/69 48% (36–60%)	399/404 99% (97–99.6%)	432/473 91% (88–94%)
CCTA using 70% Stenosis Threshold
CCTA	33/38 87% (72–96%)	416/435 96% (93–97%)	33/52 63% (49–76%)	416/421 99% (97–99.6%)	449/473 95% (93–97%)
CAC >0, then Selective CCTA	32/38 84% (69–94%)	416/435 96% (93–97%)	32/51 63% (48–76%)	416/422 99% (97–99.5%)	448/473 95% (92–97%)
CAC ≥22, then Selective CCTA	30/38 79% (63–94%)	418/435 96% (94–98%)	30/47 64% (49–77%)	418/426 98% (96–99%)	448/473 95% (92–97%)

Abbreviations as in Table 1. PPV denotes positive predictive value; NPV, negative predictive value; and CI, confidence interval. For “Selective CCTA” strategy, selective CCTA is performed after an initial CAC>0 as well as with optimal cutpoint CAC≥22.