AimsIn symptomatic patients with suspected coronary artery disease (CAD), computed tomographic angiography (CTA) improves patient selection for invasive coronary angiography (ICA) compared with functional testing. The impact of measuring fractional flow reserve by CTA (FFRCT) is unknown.Methods and resultsAt 11 sites, 584 patients with new onset chest pain were prospectively assigned to receive either usual testing (n = 287) or CTA/FFRCT (n = 297). Test interpretation and care decisions were made by the clinical care team. The primary endpoint was the percentage of those with planned ICA in whom no significant obstructive CAD (no stenosis ≥50% by core laboratory quantitative analysis or invasive FFR < 0.80) was found at ICA within 90 days. Secondary endpoints including death, myocardial infarction, and unplanned revascularization were independently and blindly adjudicated. Subjects averaged 61 ± 11 years of age, 40% were female, and the mean pre-test probability of obstructive CAD was 49 ± 17%. Among those with intended ICA (FFRCT-guided = 193; usual care = 187), no obstructive CAD was found at ICA in 24 (12%) in the CTA/FFRCT arm and 137 (73%) in the usual care arm (risk difference 61%, 95% confidence interval 53–69, P< 0.0001), with similar mean cumulative radiation exposure (9.9 vs. 9.4 mSv, P = 0.20). Invasive coronary angiography was cancelled in 61% after receiving CTA/FFRCT results. Among those with intended non-invasive testing, the rates of finding no obstructive CAD at ICA were 13% (CTA/FFRCT) and 6% (usual care; P = 0.95). Clinical event rates within 90 days were low in usual care and CTA/FFRCT arms.ConclusionsComputed tomographic angiography/fractional flow reserve by CTA was a feasible and safe alternative to ICA and was associated with a significantly lower rate of invasive angiography showing no obstructive CAD.

In patients with stable chest pain and planned invasive coronary angiography, care guided by CTA and selective FFRCT was associated with equivalent clinical outcomes and QOL, and lower costs, compared with usual care over 1-year follow-up. (The PLATFORM Study: Prospective LongitudinAl Trial of FFRct: Outcome and Resource IMpacts [PLATFORM]; NCT01943903).

It is unknown whether coronary revascularization, when added to optimal medical therapy, improves prognosis in patients with stable ischemic heart disease (SIHD) at increased risk of cardiovascular events owing to moderate or severe ischemia. OBJECTIVE To describe baseline characteristics of participants enrolled and randomized in the International Study of Comparative Health Effectiveness With Medical and Invasive Approaches (ISCHEMIA) trial and to evaluate whether qualification by stress imaging or nonimaging exercise tolerance test (ETT) influenced risk profiles. DESIGN, SETTING, AND PARTICIPANTS The ISCHEMIA trial recruited patients with SIHD with moderate or severe ischemia on stress testing. Blinded coronary computed tomography angiography was performed in most participants and reviewed by a core laboratory to exclude left main stenosis of at least 50% or no obstructive coronary artery disease (CAD) (<50% for imaging stress test and <70% for ETT). The study included 341 enrolling sites (320 randomizing) in 38 countries and patients with SIHD and moderate or severe ischemia on stress testing. Data presented were extracted on December 17, 2018. MAIN OUTCOMES AND MEASURES Enrolled, excluded, and randomized participants' baseline characteristics. No clinical outcomes are reported. RESULTS A total of 8518 patients were enrolled, and 5179 were randomized. Common reasons for exclusion were core laboratory determination of insufficient ischemia, unprotected left main stenosis of at least 50%, or no stenosis that met study obstructive CAD criteria on study coronary computed tomography angiography. Randomized participants had a median age of 64 years, with 1168 women (22.6%), 1726 nonwhite participants (33.7%), 748 Hispanic participants (15.5%), 2122 with diabetes (41.0%), and 4643 with a history of angina (89.7%). Among the 3909 participants randomized after stress imaging, core laboratory assessment of ischemia severity (in 3901 participants) was severe in 1748 (44.8%), moderate in 1600 (41.0%), mild in 317 (8.1%) and none or uninterpretable in 236 (6.0%), Among the 1270 participants who were randomized after nonimaging ETT, core laboratory determination of ischemia severity (in 1266 participants) was severe (an eligibility criterion) in 1051 (83.0%), moderate in 101 (8.0%), mild in 34 (2.7%) and none or uninterpretable in 80 (6.3%). Among the 3912 of 5179 randomized participants who underwent coronary computed tomography angiography, 79.0% had multivessel CAD (n = 2679 of 3390) and 86.8% had left anterior descending (LAD) stenosis (n = 3190 of 3677) (proximal in 46.8% [n = 1749 of 3739]). Participants undergoing ETT had greater frequency of 3-vessel CAD, LAD, and proximal LAD stenosis than participants undergoing stress imaging. CONCLUSIONS AND RELEVANCE The ISCHEMIA trial randomized an SIHD population with moderate or severe ischemia on stress testing, of whom most had multivessel CAD.