Real world impact of added FFR-CT to coronary CT angiography on clinical decision-making and patient prognosis - IMPACT FFR study.

OBJECTIVES: The addition of CT-derived fractional flow reserve (FFR-CT) increases the diagnostic accuracy of coronary CT angiography (CCTA). We assessed the impact of FFR-CT in routine clinical practice on clinical decision-making and patient prognosis in patients suspected of stable coronary artery disease (CAD). METHODS: This retrospective, single-center study compared a cohort that received CCTA with FFR-CT to a historical cohort that received CCTA before FFR-CT was available. We assessed the clinical management decisions after FFR-CT and CCTA and the rate of major adverse cardiac events (MACEs) during the 1-year follow-up using chi-square tests for independence. Kaplan-Meier curves were used to visualize the occurrence of safety outcomes over time. RESULTS: A total of 360 patients at low to intermediate risk of CAD were included, 224 in the CCTA only group, and 136 in the FFR-CT group. During follow-up, 13 MACE occurred in 12 patients, 9 (4.0%) in the CCTA group, and three (2.2%) in the FFR-CT group. Clinical management decisions differed significantly between both groups. After CCTA, 60 patients (26.5%) received optimal medical therapy (OMT) only, 115 (51.3%) invasive coronary angiography (ICA), and 49 (21.9%) single positron emission CT (SPECT). After FFR-CT, 106 patients (77.9%) received OMT only, 27 (19.9%) ICA, and three (2.2%) SPECT (p < 0.001 for all three options). The revascularization rate after ICA was similar between groups (p = 0.15). However, patients in the CCTA group more often underwent revascularization (p = 0.007). CONCLUSION: Addition of FFR-CT to CCTA led to a reduction in (invasive) diagnostic testing and less revascularizations without observed difference in outcomes after 1 year. KEY POINTS: • Previous studies have shown that computed tomography-derived fractional flow reserve improves the accuracy of coronary computed tomography angiography without changes in acquisition protocols. • This study shows that use of computed tomography-derived fractional flow reserve as gatekeeper to invasive coronary angiography in patients suspected of stable coronary artery disease leads to less invasive testing and revascularization without observed difference in outcomes after 1 year. • This could lead to a significant reduction in costs, complications and (retrospectively unnecessary) usage of diagnostic testing capacity, and a significant increase in patient satisfaction.

Impact of iodine concentration and iodine delivery rate on contrast enhancement in coronary CT angiography: a randomized multicenter trial (CT-CON).

OBJECTIVE: To compare the effect of contrast medium iodine concentration on contrast enhancement, heart rate, and injection pressure when injected at a constant iodine delivery rate in coronary CT angiography (CTA). METHODS: One thousand twenty-four patients scheduled for coronary CTA were prospectively randomized to receive one of four contrast media: iopromide 300 mg I/ml, iohexol 350 mg I/ml, iopromide 370 mg I/ml, or iomeprol 400 mg I/ml. Contrast media were delivered at an equivalent iodine delivery rate of 2.0 g I/s. Intracoronary attenuation was measured and compared (per vessel and per segment). Heart rate before and after contrast media injection was documented. Injection pressure was recorded (n = 403) during contrast medium injection and compared between groups. RESULTS: Intracoronary attenuation values were similar for the different contrast groups. The mean attenuation over all segments ranged between 384 HU for 350 mg I/ml and 395 HU for 400 mg I/ml (p = 0.079). Dose-length product (p = 0.8424), signal-to-noise ratio (all p > 0.05), time to peak (p = 0.324), and changes in heart rate (p = 0.974) were comparable between groups. The peak pressures differed: 197.4 psi for 300 mg I/ml (viscosity 4.6 mPa s), 229.8 psi for 350 mg I/ml (10.4 mPa s), 216.1 psi for 370 mg I/ml (9.5 mPa s), and 243.7 psi for 400 mg I/ml (12.6 mPa s) (p < 0.0001). CONCLUSION: Intravascular attenuation and changes in heart rate are independent of iodine concentration when contrast media are injected at the same iodine delivery rate. Differences in injection pressures are associated with the viscosity of the contrast media. KEY POINTS: • The contrast enhancement in coronary CT angiography is independent of the iodine concentration when contrast media are injected at body temperature (37 °C) with the same iodine delivery rate. • Iodine concentration does not influence the change in heart rate when contrast media are injected at identical iodine delivery rates. • For a fixed iodine delivery rate and contrast temperature, the viscosity of the contrast medium affects the injection pressure.

Iodixanol versus Iopromide at Coronary CT Angiography: Lumen Opacification and Effect on Heart Rhythm-the Randomized IsoCOR Trial.

Purpose To show that equal coronary lumen opacification can be achieved with iso- and low-osmolar contrast media when it is injected at the same iodine delivery rate with contemporary cardiac computed tomographic (CT) protocols and to investigate the cardiovascular effect of iso-osmolar contrast media and the image quality achieved. Materials and Methods Institutional review board approval and written informed consent were obtained for the Effect of Iso-osmolar Contrast Medium on Coronary Opacification and Heart Rhythm in Coronary CT Angiography, or IsoCOR, trial. Between November 2015 and August 2016, 306 patients (167 [55%] women) at least 18 years old (weight range, 50-125 kg), were prospectively randomized to receive iso-osmolar iodixanol 270 or low-osmolar iopromide 300 contrast media. All coronary segments were assessed for intraluminal opacification and image quality and were compared by using the Student t test. Heart rate, arrhythmia, patient discomfort, and adverse events also were monitored. Results Mean measured coronary attenuation values ± standard deviation were comparable between the iodixanol 270 and iopromide 300 contrast media groups (469 HU ± 167 vs 447 HU ± 166, respectively [P = .241]; 95% confidence interval: -15.1, 60.0), including those from subanalyses. Adjusted for the lower iodine concentration, the mean iodixanol 270 bolus was larger compared with that of iopromide 300 (76.8 mL ± 11.6 vs 69.7 mL ± 10.8, respectively; P < .001). The higher injection rate was associated with higher pressure (777 kPa ± 308 vs 630 kPa ± 252, respectively; P < .001). Although in the iodixanol 270 group patients experienced less heat discomfort (72% vs 86%, respectively; P < .001), no differences in heart rate or rhythm were observed. Conclusion If injected at comparable iodine delivery rates, the iso-osmolar contrast medium iodixanol 270 is not inferior to low-osmolar contrast medium iopromide 300 for assessment of coronary opacification. Iodixanol 270 was associated with less heat discomfort, but did not affect heart rate differently compared with iopromide 300. © RSNA, 2017 Online supplemental material is available for this article.

Comprehensive Cardiac CT With Myocardial Perfusion Imaging Versus Functional Testing in Suspected Coronary Artery Disease: The Multicenter, Randomized CRESCENT-II Trial.

OBJECTIVES: This study sought to assess the effectiveness, efficiency, and safety of a tiered, comprehensive cardiac computed tomography (CT) protocol in comparison with functional testing. BACKGROUND: Although CT angiography accurately rules out coronary artery disease (CAD), incorporation of CT myocardial perfusion imaging as part of a tiered diagnostic approach could improve the clinical value and efficiency of cardiac CT in the diagnostic work-up of patients with angina pectoris. METHODS: Between July 2013 and November 2015, 268 patients (mean age 58 years; 49% female) with stable angina (mean pre-test probability 54%) were prospectively randomized between cardiac CT and standard guideline-directed functional testing (95% exercise electrocardiography). The tiered cardiac CT protocol included a calcium scan, followed by CT angiography if calcium was detected. Patients with ≥50% stenosis on CT angiography underwent CT myocardial perfusion imaging. RESULTS: By 6 months, the primary endpoint, the rate of invasive coronary angiograms without a European Society of Cardiology class I indication for revascularization, was lower in the CT group than in the functional testing group (2 of 130 [1.5%] vs. 10 of 138 [7.2%]; p = 0.035), whereas the proportion of invasive angiograms with a revascularization indication was higher (88% vs. 50%; p = 0.017). The median duration until the final diagnosis was 0 (0 of 0) days in the CT group and 0 (0 of 17) in the functional testing group (p < 0.001). Overall, 13% of patients randomized to CT required further testing, compared with 37% in the functional testing group (p < 0.001). The adverse event rate was similar (3% vs. 3%; p = 1.000), although the median cumulative radiation dose was higher for the CT group (3.1 mSv [interquartile range: 1.6 to 7.8] vs. 0 mSv [interquartile range: 0.0 to 7.1]; p < 0.001). CONCLUSIONS: In patients with suspected stable CAD, a tiered cardiac CT protocol with dynamic perfusion imaging offers a fast and efficient alternative to functional testing. (Comprehensive Cardiac CT Versus Exercise Testing in Suspected Coronary Artery Disease 2 [CRESCENT2]; NCT02291484).

Correction to: Age-Related Effects of Bariatric Surgery on Early Atherosclerosis and Cardiovascular Risk Reduction.

Frederik H. W. Jonker and Vera A. A. van Houten contributed equally to this work.

Age-Related Effects of Bariatric Surgery on Early Atherosclerosis and Cardiovascular Risk Reduction.

BACKGROUND: Carotid intima-media thickness (CIMT) is increasingly used as a prognostic indicator for early atherosclerosis and the development of cardiovascular disease. The objective of this study is to assess the exact effects of bariatric surgery on CIMT reduction in different age groups. METHODS: CIMT was measured just proximal to the bifurcation of the carotid artery in 166 patients with mean body mass index of 43.4 kg/m2 before and at 6 and 12 months after bariatric surgery. Preoperative CIMT and Framingham Risk Score (FRS) were compared to measurements at 6 and 12 months, postoperatively. Impact of age on CIMT change and cardiovascular risk reduction was analyzed. RESULTS: Median follow-up was 12 months; 12% were lost to follow-up. Mean CIMT values at 12 months after bariatric surgery were significantly lower compared to baseline (0.619 vs. 0.587 mm, p = 0.005 in women and 0.675 vs. 0.622 mm, p = 0.037 in men, respectively), and these effects were statistically significant in all age groups. The mean reduction of CIMT for patients < 50 years at 12 months was 0.043 mm (- 7.0%), while CIMT was reduced with 0.013 mm for patients ≥ 50 years (- 1.9%, p = 0.022). At 12 months after bariatric surgery, FRS had decreased with 52% in patients < 50 years as compared with 35% in patients ≥ 50 years (p = 0.025). CONCLUSIONS: Bariatric surgery resulted in a significant CIMT decrease in patients with morbid obesity in all evaluated age categories. These beneficial effects of bariatric surgery were more pronounced in younger patients, while cardiovascular risk reduction by bariatric surgery appeared inferior in patients of 50 years and older.

Sex Differences in the Performance of Cardiac Computed Tomography Compared With Functional Testing in Evaluating Stable Chest Pain: Subanalysis of the Multicenter, Randomized CRESCENT Trial (Calcium Imaging and Selective CT Angiography in Comparison to Functional Testing for Suspected Coronary Artery Disease).

BACKGROUND: Cardiac computed tomography (CT) represents an alternative diagnostic strategy for women with suspected coronary artery disease, with potential benefits in terms of effectiveness and cost-efficiency. METHODS AND RESULTS: The CRESCENT trial (Calcium Imaging and Selective CT Angiography in Comparison to Functional Testing for Suspected Coronary Artery Disease) prospectively randomized 350 patients with stable angina (55% women; aged 55±10 years), mostly with an intermediate coronary artery disease probability, between cardiac CT and functional testing. The tiered cardiac CT protocol included a calcium scan followed by CT angiography if the Agatston calcium score was between 1 and 400. Patients with test-specific contraindications were not excluded from study participation. Sex differences were studied as a prespecified subanalysis. Enrolled women presented more frequently with atypical chest pain and had a lower pretest probability of coronary artery disease compared with men. Independently of these differences, cardiac CT led in both sexes to a fast final diagnosis when compared with functional testing, although the effect was larger in women (P interaction=0.01). The reduced need for further testing after CT, compared with functional testing, was most evident in women (P interaction=0.009). However, no sex interaction was observed with respect to changes in angina and quality of life, cumulative diagnostic costs, and applied radiation dose (all P interactions≥0.097). CONCLUSIONS: Cardiac CT is more efficient in women than in men in terms of time to reach the final diagnosis and downstream testing. However, overall clinical outcome showed no significant difference between women and men after 1 year. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01393028.

Calcium imaging and selective computed tomography angiography in comparison to functional testing for suspected coronary artery disease: the multicentre, randomized CRESCENT trial.

AIMS: To compare the effectiveness and safety of a cardiac computed tomography (CT) algorithm with functional testing in patients with symptoms suggestive of coronary artery disease (CAD). METHODS AND RESULTS: Between April 2011 and July 2013, 350 patients with stable angina, referred to the outpatient clinic of four Dutch hospitals, were prospectively randomized between cardiac CT and functional testing (2 : 1 ratio). The tiered cardiac CT protocol included a calcium scan followed by CT angiography if the Agatston calcium score was between 1 and 400. Patients with test-specific contraindications were not excluded from study participation. By 1 year, fewer patients randomized to cardiac CT reported anginal complaints (P = 0.012). The cumulative radiation dose was slightly higher in the CT group (6.6 ± 8.7 vs. 6.1 ± 9.3 mSv; P < 0.0001). After 1.2 years, event-free survival was 96.7% for patients randomized to CT and 89.8% for patients randomized to functional testing (P = 0.011). After CT, the final diagnosis was established sooner (P < 0.0001), and additional downstream testing was required less frequently (25 vs. 53%, P < 0.0001), resulting in lower cumulative diagnostic costs (€369 vs. €440; P < 0.0001). CONCLUSION: For patients with suspected stable CAD, a tiered cardiac CT protocol offers an effective and safe alternative to functional testing. Incorporating the calcium scan into the diagnostic workup was safe and lowered diagnostic expenses and radiation exposure.