Table 4. Studies evaluating outcomes of symptomatic patients who underwent coronary computed tomography angiography and had a coronary artery calcium of zero.

Study	Population	Outcomes	Percentage of participants with CAC of zero	Outcomes in participants with CAC of zero
Villines et al., 2011, CONFIRM [33]	10,037 symptomatic patients without known CAD who underwent CCTA with CAC	All-cause mortality and the composite endpoint of mortality, MI, or late coronary revascularization after median follow-up of 2.1 years	51%	0.4% all-cause mortality. 0.9% for the composite endpoint.
Lubbers et al., 2016, CRESCENT [34]	242 patients with stable angina were prospectively randomized to tiered cardiac CT protocol with CAC and subsequent CCTA if CAC present or >70% pre-test probability	Composite endpoint of all-cause mortality, non-fatal MI, major stroke, unstable angina pectoris with objective ischemia and/or requiring revascularization after mean follow-up of 1.2 years	41%	No events in all 98 patients ruled out for CAD based on zero CAC.
Budoff et al., 2017, PROMISE [35]	4,209 patients with stable chest pain or dyspnea and intermediate pre-test probability for obstructive CAD randomized to CCTA with CAC	Primary endpoint of all-cause death, MI, or unstable angina hospitalization after median follow-up of 26.1 months	35%	1.4% for the primary endpoint.
Lubbers et al., 2018, CRESCENT-II [36]	130 patients with stable angina were prospectively randomized to tiered cardiac CT protocol with CAC and subsequent CCTA if CAC present or >80% pre-test probability	Major adverse events including death, nonfatal MI, unstable angina, urgent revascularization, and stroke after mean follow-up of 8 months	39%	No events in all 45 patients ruled out for CAD based on zero CAC
Williams et al., 2019, SCOT-HEART [37]	1,769 patients with stable chest pain in outpatient clinic were randomized to CCTA with CAC	Primary clinical endpoint of coronary heart disease death or nonfatal MI after median follow-up of 4.7 years	39%	Primary clinical endpoint of ~1% (approximated from Fig 4)

CAC, coronary artery calcium; CCTA, coronary computed tomography angiography; CAD, coronary artery disease; CRESCENT, Computed Tomography vs. Exercise Testing in Suspected Coronary Artery Disease; CONFIRM, Coronary CT Angiography Evaluation for Clinical Outcomes: An International Multicenter Registry; MI, myocardial infarction; PROMISE, Prospective Multicenter Imaging Study for Evaluation of Chest Pain; SCOT-HEART, Scottish COmputed Tomography of the HEART Trial.