Diagnostic Performance of CT-Derived Fractional Flow Reserve in Australian Patients Referred for Invasive Coronary Angiography.

BACKGROUND: Non-invasive computed tomography (CT)-derived fractional flow reserve (FFRCT) is computed from standard coronary CT angiography (CTA) datasets and provides accurate vessel-specific ischaemia assessment of coronary artery disease (CAD). To date, the technique and its diagnostic performance has not been verified in the Australian clinical context. The aim of this study was to describe and compare the diagnostic performance of FFRCT and CTA for the detection of vessel-specific ischaemia as determined by invasive fractional flow reserve (FFR) in the Australian patient population. METHODS: One-hundred-and-nine patients (219 vessels) referred for clinically mandated invasive angiography were retrospectively assessed. Each patient underwent research mandated CTA and FFRCT within 3 months of invasive angiography and invasive FFR assessment. Independent core laboratory assessments were made to determine visual CTA stenosis, FFRCT and invasive FFR values. FFRCT values were matched with the corresponding invasive FFR measurement taken at the given wire position. Visual CTA stenosis ≥50%, FFRCT values ≤0.8 and invasive FFR values ≤0.8 were considered significant for ischaemia. RESULTS: Per vessel accuracy, sensitivity, specificity, positive predictive value and negative predictive value of FFRCT were 80.4%, 80.0%, 80.6%, 64.9% and 90.0% respectively. Corresponding values for CTA were 75.1%, 87.1%, 69.2%, 58.1% and 91.7% respectively. In receiver operating characteristic curve analysis, FFRCT demonstrated superior area under the curve (AUC) compared with CTA in both per vessel (0.87 vs 0.77, p=0.004) and per patient analysis (0.86 vs 0.74, p=0.011). Per vessel AUC of combined CTA and FFRCT was superior to CTA alone (0.89 vs 0.77, p<0.0001). CONCLUSION: In this cohort of Australian patients, the diagnostic performance of FFRCT was found to be comparable to existing international literature, with demonstrated improvement in performance compared with CTA alone for the detection of vessel-specific ischaemia.

Early Versus Standard Care Invasive Examination and Treatment of Patients With Non-ST-Segment Elevation Acute Coronary Syndrome.

BACKGROUND: The optimal timing of invasive coronary angiography (ICA) and revascularization in patients with non-ST-segment elevation acute coronary syndrome is not well defined. We tested the hypothesis that a strategy of very early ICA and possible revascularization within 12 hours of diagnosis is superior to an invasive strategy performed within 48 to 72 hours in terms of clinical outcomes. METHODS: Patients admitted with clinical suspicion of non-ST-segment elevation acute coronary syndrome in the Capital Region of Copenhagen, Denmark, were screened for inclusion in the VERDICT trial (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography) ( ClinicalTrials.gov NCT02061891). Patients with ECG changes indicating new ischemia or elevated troponin, in whom ICA was clinically indicated and deemed logistically feasible within 12 hours, were randomized 1:1 to ICA within 12 hours or standard invasive care within 48 to 72 hours. The primary end point was a combination of all-cause death, nonfatal recurrent myocardial infarction, hospital admission for refractory myocardial ischemia, or hospital admission for heart failure. RESULTS: A total of 2147 patients were randomized; 1075 patients allocated to very early invasive evaluation had ICA performed at a median of 4.7 hours after randomization, whereas 1072 patients assigned to standard invasive care had ICA performed 61.6 hours after randomization. Among patients with significant coronary artery disease identified by ICA, coronary revascularization was performed in 88.4% (very early ICA) and 83.1% (standard invasive care). Within a median follow-up time of 4.3 (interquartile range, 4.1-4.4) years, the primary end point occurred in 296 (27.5%) of participants in the very early ICA group and 316 (29.5%) in the standard care group (hazard ratio, 0.92; 95% CI, 0.78-1.08). Among patients with a GRACE risk score (Global Registry of Acute Coronary Events) >140, a very early invasive treatment strategy improved the primary outcome compared with the standard invasive treatment (hazard ratio, 0.81; 95% CI, 0.67-1.01; P value for interaction=0.023). CONCLUSIONS: A strategy of very early invasive coronary evaluation does not improve overall long-term clinical outcome compared with an invasive strategy conducted within 2 to 3 days in patients with non-ST-segment elevation acute coronary syndrome. However, in patients with the highest risk, very early invasive therapy improves long-term outcomes. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02061891.

Functional Information in Coronary Artery Disease: The Case of Computed Tomography Myocardial Perfusion.

PURPOSE OF REVIEW: To review methodological and logistical aspects of CT myocardial perfusion, current clinical evidence and possible future directions, with specific focus on use in patients with coronary artery disease (CAD). RECENT FINDINGS: CT myocardial perfusion imaging may be performed as an add-on to standard coronary CT angiography (CCTA), to identify regions of myocardial hypoperfusion, at rest and during adenosine stress. The principle of measurement is well-validated in animal experimental models, and CT myocardial perfusion imaging has a high degree of concordance with already clinically available perfusion imaging methods. Combining CCTA and CT myocardial perfusion imaging increases the diagnostic accuracy to identify patients with CAD associated with ischemia. In patients suspected of CAD, CCTA frequently detects coronary atherosclerotic lesions, in which revascularization could be clinically beneficial. CT myocardial perfusion imaging may be helpful to identify coronary lesions associated with myocardial ischemia, and thus potentially suitable for coronary intervention.

Myocardial perfusion 320-row multidetector computed tomography-guided treatment strategy for the clinical management of patients with recent acute-onset chest pain: Design of the CArdiac cT in the treatment of acute CHest pain (CATCH)-2 randomized controlled trial.

AIMS: Patients admitted with chest pain are a diagnostic challenge because the majority does not have coronary artery disease (CAD). Assessment of CAD with coronary computed tomography angiography (CCTA) is safe, cost-effective, and accurate, albeit with a modest specificity. Stress myocardial computed tomography perfusion (CTP) has been shown to increase the specificity when added to CCTA, without lowering the sensitivity. This article describes the design of a randomized controlled trial, CATCH-2, comparing a clinical diagnostic management strategy of CCTA alone against CCTA in combination with CTP. METHODS: Patients with acute-onset chest pain older than 50 years and with at least one cardiovascular risk factor for CAD are being prospectively enrolled to this study from 6 different clinical sites since October 2013. A total of 600 patients will be included. Patients are randomized 1:1 to clinical management based on CCTA or on CCTA in combination with CTP, determining the need for further testing with invasive coronary angiography including measurement of the fractional flow reserve in vessels with coronary artery lesions. Patients are scanned with a 320-row multidetector computed tomography scanner. Decisions to revascularize the patients are taken by the invasive cardiologist independently of the study allocation. The primary end point is the frequency of revascularization. Secondary end points of clinical outcome are also recorded. DISCUSSION: The CATCH-2 will determine whether CCTA in combination with CTP is diagnostically superior to CCTA alone in the management of patients with acute-onset chest pain.

Respiratory influence on left atrial volume calculation with 3D-echocardiography.

BACKGROUND: Left atrial volume (LAV) estimation with 3D echocardiography has been shown to be more accurate than 2D volume calculation. However, little is known about the possible effect of respiratory movements on the accuracy of the measurement. METHODS: 100 consecutive patients admitted with chest pain were examined with 3D echocardiography and LAV was quantified during inspiratory breath hold, expiratory breath hold and during free breathing. RESULTS: Of the 100 patients, only 65 had an echocardiographic window that allowed for 3D echocardiography in the entire respiratory cycle. Mean atrial end diastolic volume was 45.4 ± 14.5 during inspiratory breath hold, 46.4 ± 14.8 during expiratory breath hold and 45.6 ± 14.3 during free respiration. Mean end systolic volume was 17.6 ± 7.8 during inspiratory breath hold, 18.8 ± 8.0 during expiratory breath hold and 18.3 ± 8.0 during free respiration. No significant differences were seen in any of the measured parameters. CONCLUSIONS: The present study adds to the feasibility of 3D LAV quantitation. LAV estimation by 3D echocardiography may be performed during either end-expiratory or end-inspiratory breath-hold without any significant difference in the calculated volume. Also, the LAV estimation may be performed during free breathing.

Normal values of myocardial blood flow measured with dynamic myocardial computed tomography perfusion.

AIMS: Dynamic myocardial computed tomography (CT) perfusion (DM-CTP) can, in combination with coronary CT angiography (CCTA), provide anatomical and functional evaluation of coronary artery disease (CAD). However, normal values of myocardial blood flow (MBF) are needed to identify impaired myocardial blood supply in patients with suspected CAD. We aimed to establish normal values for MBF measured using DM-CTP, to assess the effects of age and sex, and to assess regional distribution of MBF. METHODS AND RESULTS: A total of 82 healthy individuals (46 women) aged 45-78 years with normal coronary arteries by CCTA underwent either rest and adenosine stress DM-CTP (n = 30) or adenosine-induced stress DM-CTP only (n = 52). Global and segmental MBF were assessed. Global MBF at rest and during stress were 0.93 ± 0.42 and 3.58 ± 1.14 mL/min/g, respectively. MBF was not different between the sexes (P = 0.88 at rest and P = 0.61 during stress), and no correlation was observed between MBF and age (P = 0.08 at rest and P = 0.82 during stress). Among the 16 myocardial segments, significant intersegmental differences were found (P < 0.01), which was not related to age, sex, or coronary dominance. CONCLUSION: MBF assessed by DM-CTP in healthy individuals with normal coronary arteries displays significant intersegmental heterogeneity which does not seem to be affected by age, sex, or coronary dominance. Normal values of MBF may be helpful in the clinical evaluation of suspected myocardial ischaemia using DM-CTP.

Early-onset vs late-onset preeclampsia and risk of coronary atherosclerosis later in life: a clinical follow-up study.

BACKGROUND: Younger women with previous preeclampsia have an increased risk of coronary atherosclerosis. It is unknown if this risk is associated with the time of onset of preeclampsia. OBJECTIVE: This study aimed to investigate if women with early-onset preeclampsia have a higher risk of coronary atherosclerosis compared with women with late-onset preeclampsia, independent of other perinatal risk factors. STUDY DESIGN: A total of 911 women with previous preeclampsia aged 35 to 55 years participated in a clinical follow-up study, including clinical examination, comprehensive questionnaires, and cardiac computed tomography scan 13 years (range, 0-28) after index pregnancy. Early- and late-onset preeclampsia were defined as gestational age at delivery of <34+0 and ≥34+0 gestational weeks, respectively. The primary outcome of the study was the presence of coronary atherosclerosis on the cardiac computed tomography. A logistic regression analysis was performed to investigate the association between time of onset of preeclampsia, perinatal risk factors, and the primary outcome. RESULTS: Women with early-onset preeclampsia (N=139) were older (46.2±5.7 vs 44.4±5.5 years; P<.001), more likely to have hypertension (51.1% vs 35.1%; P≤.001), and had a higher body mass index (27.9±6.3 vs 26.9±5.5 kg/m2; P=.051) compared with women with late-onset preeclampsia (N=772) at follow-up. The prevalence of the primary outcome (coronary atherosclerosis) on the cardiac computed tomography among women with early- and late-onset preeclampsia was 28.8% vs 22.2%, respectively (P=.088; adjusted odds ratio, 1.74; 95% confidence interval, 1.01-3.01; P=.045 after adjustment for maternal age at index pregnancy, prepregnancy body mass index, parity, diabetes in pregnancy, smoking in pregnancy, offspring birthweight and sex, and follow-up length). CONCLUSION: Women with early-onset preeclampsia had a slightly higher risk of coronary atherosclerosis compared with women with late-onset preeclampsia. However, according to the current evidence, it does not seem indicated to limit screening, diagnostic, and preventive measures for cardiovascular disease only to women with early-onset preeclampsia.

The importance of nonobstructive plaque characteristics in symptomatic and asymptomatic coronary artery disease.

BACKGROUND: We examined obstructive and nonobstructive plaque volumes in populations with subclinical and clinically manifested coronary artery disease (CAD) using quantitative computed tomography (QCT). METHODS: 855 participants with CAD (274 asymptomatic individuals, 254 acute chest pain patients without acute coronary syndrome (ACS), and 327 patients with ACS) underwent QCT of proximal coronary segments to assess participant-level plaque volumes of dense calcium, fibrous, fibrofatty, and necrotic core tissue. RESULTS: Nonobstructive (<50% stenosis) plaque volumes were greater than obstructive plaque volumes, irrespective of population (all p<0.0001): Asymptomatic individuals (mean (95% CI)): 218 [190-250] vs. 16 [12-22] mm3; acute chest pain patients without ACS: 300 [263-341] vs. 51 [41-62] mm3; patients with ACS: 370 [332-412] vs. 159 [139-182] mm3. After multivariable adjustment, nonobstructive fibrous and fibrofatty tissue volumes were greater in acute chest pain patients without ACS compared to asymptomatic individuals (fibrous tissue: 122 [107-139] vs. 175 [155-197] mm3, p<0.01; fibrofatty tissue: 44 [38-50] vs. 71 [63-80] mm3, p<0.01. Necrotic core tissue was greater in ACS patients (29 [26-33] mm3) compared to both asymptomatic individuals (15 [13-18] mm3, p<0.0001) and acute chest pain patients without ACS (21 [18-24] mm3, p<0.05). Nonobstructive dense calcium volumes did not differ between the three populations: 29 [24-36], 29 [23-35], and 41 [34-48] mm3, p>0.3 respectively. CONCLUSION: Nonobstructive CAD was the predominant contributor to total atherosclerotic plaque volume in both subclinical and clinically manifested CAD. Nonobstructive fibrous, fibrofatty and necrotic core tissue volumes increased with worsening clinical presentation, while nonobstructive dense calcium tissue volumes did not.

Aortic dimensions in women with previous pre-eclampsia.

BACKGROUND: Pre-eclampsia is a pregnancy related disorder associated with hypertension and vascular inflammation, factors that are also involved in the pathological pathway of aortic dilatation and aneurysm development. It is, however, unknown if younger women with previous pre-eclampsia have increased aortic dimensions. We tested the hypothesis that previous pre-eclampsia is associated with increased aortic dimensions in younger women. METHODS: The study was a cross-sectional cohort study of women with previous pre-eclampsia, aged 40-55, from the PRECIOUS population matched by age and parity with women from the general population. Using contrast-enhanced CT, aortic diameters were measured in the aortic root, ascending aorta, descending aorta, at the level of the diaphragm, suprarenal aorta, and infrarenal aorta. RESULTS: 1355 women (684 with previous pre-eclampsia and 671 from the general population), with a mean (standard deviation) age of 46.9 (4.4) were included. The pre-eclampsia group had larger mean (standard deviation) aortic diameters (mm) in all measured segments from the ascending to the infrarenal aorta (ascending: 33.4 (4.0) vs. 31.4 (3.7), descending: 23.9 (2.1) vs. 23.3 (2.0), diaphragm: 20.8 (1.8) vs. 20.4 (1.8), suprarenal: 22.9 (1.9) vs. 22.0 (2.0), infrarenal: 19.3 (1.6) vs. 18.6 (1.7), p â€‹< â€‹0.001 for all, also after adjustment for age, height, parity, menopause, dyslipidemia, smoking and chronic hypertension. Guideline-defined ascending aortic aneurysms were found in 8 vs 2 women (p â€‹= â€‹0.12). CONCLUSIONS: Women with previous pre-eclampsia have larger aortic dimensions compared with women from the general population. Pre-eclampsia was found to be an independent risk factor associated with a larger aortic diameter.

Pseudoaneurysm of the sinus of Valsalva with coronary artery compression as the primary manifestation of infective endocarditis: a case report.

A pseudoaneurysm of the native sinus of Valsalva compressing a coronary artery is extremely rare. Herein, the case is reported of infective endocarditis with a pseudoaneurysm of the sinus of Valsalva compressing the right coronary artery as the primary diagnostic finding, and its successful treatment. It is suggested that patients with suspected pseudoaneurysms of the sinus of Valsalva should undergo cardiac computed tomographic angiography for diagnosis of this condition.

Technical Considerations for Dynamic Myocardial Computed Tomography Perfusion as Part of a Comprehensive Evaluation of Coronary Artery Disease Using Computed Tomography.

Dynamic myocardial computed tomography perfusion (DM-CTP) has good diagnostic accuracy for identifying myocardial ischemia as compared with both invasive and noninvasive reference standards. However, DM-CTP has not yet been implemented in the routine clinical examination of patients with suspected or known coronary artery disease. An important hurdle in the clinical dissemination of the method is the development of the DM-CTP acquisition protocol and image analysis. Therefore, the aim of this article is to provide a review of critical parameters in the design and execution of DM-CTP to optimize each step of the examination and avoid common mistakes. We aim to support potential users in the successful implementation and performance of DM-CTP in daily practice. When performed appropriately, DM-CTP may support clinical decision making. In addition, when combined with coronary computed tomography angiography, it has the potential to shorten the time to diagnosis by providing immediate visualization of both coronary atherosclerosis and its functional relevance using one single modality.

Quantification of myocardial blood flow using dynamic myocardial CT perfusion compared with 82Rb PET.

PURPOSE: Absolute measures of myocardial blood flow (MBF) obtained with dynamic myocardial CT perfusion (DM-CTP) are underestimated when compared with reference standards. This is to some extent explained by incomplete extraction of iodinated contrast agent (iCA) to the myocardial tissue. We aimed to establish an extraction function for iCA, use the function to calculate MBFCT and to compare this with MBF measured with 82Rb positron emission tomography (PET). MATERIALS AND METHODS: Healthy individuals without coronary artery disease (CAD) were examined with 82Rb PET and DM-CTP. The factors a and ß of the generalized Renkin-Crone model were estimated using a non-linear least squares model. The factors providing the best fit for the data were subsequently used to calculate MBFCT. RESULTS: Of consecutive 91 individuals examined, 79 were eligible for analysis. The factors a and ß providing the best fit of the nonlinear least-squares model to the data were a â€‹= â€‹0.614 and ߠ​= â€‹0.218 (R-squared â€‹= â€‹0.81). Conversion of the CT inflow parameter (K1) values using the derived extraction function resulted in a significant correlation between MBF measured during stress using CT and PET (P â€‹= â€‹0.039). CONCLUSION: In healthy individuals, flow estimates obtained with dynamic myocardial CT perfusion during stress were, after conversion to MBF using the extraction of iodinated CT contrast agent, correlated with absolute MBF quantified with 82Rb PET.

Coronary CT and timing of invasive coronary angiography in patients ≥75 years old with non-ST segment elevation acute coronary syndromes.

BACKGROUND: The ability of coronary CT angiography (cCTA) to rule out significant coronary artery disease (CAD) in older patients with non-ST segment elevation acute coronary syndromes (NSTEACS) is unclear since valid cCTA analysis may be limited by extensive coronary artery calcification. In addition, the effect of very early invasive coronary angiography (ICA) with possible revascularisation is debated. METHODS: This is a posthoc analysis of patients ≥75 years included in the Very Early vs Standard Care Invasive Examination and Treatment of Patients with Non-ST-Segment Elevation Acute Coronary Syndrome Trial. cCTA was performed prior to the ICA. The diagnostic accuracy of cCTA was investigated. Presence of a coronary artery stenosis ≥50% by subsequent ICA was used as reference. Patients were randomised to a very early (within 12 hours of diagnosis) or a standard ICA (within 48-72 hours of diagnosis). The primary composite endpoint was 5-year all-cause mortality, non-fatal recurrent myocardial infarction or hospital admission for refractory myocardial ischaemia or heart failure. RESULTS: Of 452 (21%) patients ≥75 years, 161 (35.6%) underwent cCTA. 19% of cCTAs excluded significant CAD. The negative predictive value (NPV) of cCTA was 94% (95% CI 79 to 99) and the sensitivity 98% (95% CI 94 to 100). No significant differences in the frequency of primary endpoints were seen in patients randomised to very early ICA (at 5-year follow-up, n=100 (46.9%) vs 122 (51.0%), log-rank p=0.357). CONCLUSION: In patients ≥75 years with NSTEACS, cCTA before ICA showed a high NPV. A very early ICA <12 hours of diagnosis did not significantly improve long-term clinical outcomes.

Early Coronary Atherosclerosis in Women With Previous Preeclampsia.

BACKGROUND: Women with previous preeclampsia have an increased risk of coronary artery disease later in life. OBJECTIVES: This study aimed to determine the prevalence of coronary atherosclerosis in younger women with previous preeclampsia in comparison with women from the general population. METHODS: Women aged 40-55 years with previous preeclampsia were matched 1:1 on age and parity with women from the general population. Participants completed an extensive questionnaire, a clinical examination, and a coronary computed tomography angiography (CTA). The main study outcome was the prevalence of any coronary atherosclerosis on coronary CTA or a calcium score >0 in case of a nondiagnostic coronary CTA. RESULTS: A total of 1,417 women, with a mean age of 47 years, were included (708 women with previous preeclampsia and 709 control subjects from the general population). Women with previous preeclampsia were more likely to have hypertension (284 [40.1%] vs 162 [22.8%]; P < 0.001), dyslipidemia (338 [47.7%] vs 296 [41.7%]; P = 0.023), diabetes mellitus (24 [3.4%] vs 8 [1.1%]; P = 0.004), and high body mass index (27.3 ± 5.7 kg/m2 vs 25.0 ± 4.2 kg/m2; P < 0.001). Cardiac computed tomography was performed in all women. The prevalence of any coronary atherosclerosis was higher in the preeclampsia group (193 [27.4%] vs 141 [20.0%]; P = 0.001) with an OR: 1.41 (95% CI: 1.08-1.85; P = 0.012) after adjustment for age, dyslipidemia, diabetes mellitus, smoking, body mass index, menopause, and parity. CONCLUSIONS: Younger women with previous preeclampsia had a slightly higher prevalence of coronary atherosclerosis compared with age- and parity-matched women from the general population. Preeclampsia remained an independent risk factor after adjustment for traditional cardiovascular risk factors. (The CoPenHagen PREeClampsia and cardIOvascUlar diSease study [CPH-PRECIOUS]; NCT03949829).

Optimization of image sampling rate to lower the radiation dose of dynamic myocardial CT perfusion.

BACKGROUND: Dynamic myocardial CT perfusion (CTP) has emerged as a potential strategy to combine anatomical and functional evaluation in a single modality. However, this method results in a high radiation dose. METHODS: Dynamic CTP was performed in 56 patients with suspected or known ischemic heart disease of whom 48 had complete CT-data. Datasets with reduced sampling rate of 2- and 3 RR-intervals (2RR and 3RR) were constructed post hoc. Myocardial blood flow (MBF) estimates from the 2RR and 3RR datasets were compared with estimates based on the full dataset (1RR) using the two one-sided test of equivalence for paired samples. RESULTS: Significant equivalence was found for rest MBFLV (p â€‹< â€‹0.001), stress MBFLV (p â€‹< â€‹0.001) and for the CFRLV (p â€‹= â€‹0.005) when comparing 2RR blood flow estimates with the results based on the 1RR dataset. The 2RR reconstruction protocol led to an estimated reduction in radiation dose of 35.4 â€‹± â€‹3.8%. CONCLUSION: MBF can be quantitated with dynamic CTP using a sampling strategy of one volume for every second heartbeat. This strategy could lead to a significant reduction in radiation dose.

Importance of Risk Assessment in Timing of Invasive Coronary Evaluation and Treatment of Patients With Non-ST-Segment-Elevation Acute Coronary Syndrome: Insights From the VERDICT Trial.

Background The optimal timing of invasive examination and treatment of high-risk patients with non-ST-segment-elevation acute coronary syndrome has not been established. We investigated the efficacy of early invasive coronary angiography compared with standard-care invasive coronary angiography on the risk of all-cause mortality according to the GRACE (Global Registry of Acute Coronary Events) risk score in a predefined subgroup analysis of the VERDICT (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography) trial. Methods and Results Patients with clinical suspicion of non-ST-segment-elevation acute coronary syndrome with ECG changes indicating new ischemia and/or elevated troponin, in whom invasive coronary angiography was clinically indicated and deemed logistically feasible within 12 hours, were eligible for inclusion. Patients were randomized 1:1 to an early (≤12 hours) or standard (48-72 hours) invasive strategy. The primary outcome of the present study was all-cause mortality. Of 2147 patients randomized in the VERDICT trial, 2092 patients had an available GRACE risk score. Of these, 1021 (48.8%) patients had a GRACE score >140. During a median follow-up of 4.1 years, 192 (18.8%) and 54 (5.0%) patients died in the high and low GRACE score groups, respectively. The risk of death with the early invasive strategy was increased in patients with a GRACE score ≤140 (hazard ratio [HR], 2.04 [95% CI, 1.16-3.59]), whereas there was a trend toward a decreased risk of death with the early invasive strategy in patients with a GRACE score >140 (HR, 0.83 [95% CI, 0.63-1.10]) (Pinteraction=0.006). Conclusions In patients with non-ST-segment-elevation acute coronary syndrome, we found a significant interaction between timing of invasive coronary angiography and GRACE score on the risk of death. Randomized clinical trials are warranted to establish the efficacy and safety among high-risk and low-risk patients with non-ST-segment-elevation acute coronary syndrome. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02061891.

Prognostic Value of Coronary CT Angiography in Patients With Non-ST-Segment Elevation Acute Coronary Syndromes.

BACKGROUND: Severity and extent of coronary artery disease (CAD) assessed by invasive coronary angiography (ICA) guide treatment and may predict clinical outcome in patients with non-ST-segment elevation acute coronary syndrome (NSTEACS). OBJECTIVES: This study tested the hypothesis that coronary computed tomography angiography (CTA) is equivalent to ICA for risk assessment in patients with NSTEACS. METHODS: The VERDICT (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography in Patients With Acute Coronary Syndromes) trial evaluated timing of treatment in relation to outcome in patients with NSTEACS and included a clinically blinded coronary CTA conducted prior to ICA. Severity of CAD was defined as obstructive (coronary stenosis ≥50%) or nonobstructive. Extent of CAD was defined as high risk (obstructive left main or proximal left anterior descending artery stenosis and/or multivessel disease) or non-high risk. The primary endpoint was a composite of all-cause death, nonfatal recurrent myocardial infarction, hospital admission for refractory myocardial ischemia, or heart failure. RESULTS: Coronary CTA and ICA were conducted in 978 patients. During a median follow-up time of 4.2 years (interquartile range: 2.7 to 5.5 years), the primary endpoint occurred in 208 patients (21.3%). The rate of the primary endpoint was up to 1.7-fold higher in patients with obstructive CAD compared with in patients with nonobstructive CAD as defined by coronary CTA (hazard ratio [HR]: 1.74; 95% confidence interval [CI]: 1.22 to 2.49; p = 0.002) or ICA (HR: 1.54; 95% CI: 1.13 to 2.11; p = 0.007). In patients with high-risk CAD, the rate of the primary endpoint was 1.5-fold higher compared with the rate in those with non-high-risk CAD as defined by coronary CTA (HR: 1.56; 95% CI: 1.18 to 2.07; p = 0.002). A similar trend was noted for ICA (HR: 1.28; 95% CI: 0.98 to 1.69; p = 0.07). CONCLUSIONS: Coronary CTA is equivalent to ICA for the assessment of long-term risk in patients with NSTEACS. (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography in Patients With Acute Coronary Syndromes [VERDICT]; NCT02061891).

Coronary CT Angiography in Patients With Non-ST-Segment Elevation Acute Coronary Syndrome.

BACKGROUND: In patients with non-ST-segment elevation acute coronary syndrome (NSTEACS), coronary pathology may range from structurally normal vessels to severe coronary artery disease. OBJECTIVES: The purpose of this study was to test if coronary computed tomography angiography (CTA) may be used to exclude coronary artery stenosis ≥50% in patients with NSTEACS. METHODS: The VERDICT (Very Early Versus Deferred Invasive Evaluation Using Computerized Tomography in Patients With Acute Coronary Syndromes) trial (NCT02061891) evaluated the outcome of patients with confirmed NSTEACS randomized 1:1 to very early (within 12 h) or standard (48 to 72 h) invasive coronary angiography (ICA). As an observational component of the trial, a clinically blinded coronary CTA was conducted prior to ICA in both groups. The primary endpoint was the ability of coronary CTA to rule out coronary artery stenosis (≥50% stenosis) in the entire population, expressed as the negative predictive value (NPV), using ICA as the reference standard. RESULTS: Coronary CTA was conducted in 1,023 patients-very early, 2.5 h (interquartile range [IQR]: 1.8 to 4.2 h), n = 583; and standard, 59.9 h (IQR: 38.9 to 86.7 h); n = 440 after the diagnosis of NSTEACS was made. A coronary stenosis ≥50% was found by coronary CTA in 68.9% and by ICA in 67.4% of the patients. Per-patient NPV of coronary CTA was 90.9% (95% confidence interval [CI]: 86.8% to 94.1%) and the positive predictive value, sensitivity, and specificity were 87.9% (95% CI: 85.3% to 90.1%), 96.5% (95% CI: 94.9% to 97.8%) and 72.4% (95% CI: 67.2% to 77.1%), respectively. NPV was not influenced by patient characteristics or clinical risk profile and was similar in the very early and the standard strategy group. CONCLUSIONS: Coronary CTA has a high diagnostic accuracy to rule out clinically significant coronary artery disease in patients with NSTEACS.

Non-invasive CT-derived fractional flow reserve and static rest and stress CT myocardial perfusion imaging for detection of haemodynamically significant coronary stenosis.

Computed tomography derived fractional flow reserve (FFRCT) and computed tomography stress myocardial perfusion imaging (CTP) are techniques to assess haemodynamic significance of coronary stenosis. To compare the diagnostic performance of FFRCT and static rest/stress CTP in detecting fractional flow reserve (FFR) defined haemodynamically-significant stenosis (FFR ≤ 0.8). Fifty-one patients (96 vessels) with suspected coronary artery disease from a single institution planned for elective invasive-angiography prospectively underwent research indicated 320-detector-CT-coronary-angiography (CTA) and adenosine-stress CTP and invasive FFR. Analyses were performed in separate core-laboratories for FFRCT and CTP blinded to FFR results. Myocardial perfusion was assessed visually and semi-quantitatively by transmural perfusion ratio (TPR). Invasive FFR ≤ 0.8 was present in 33% of vessels and 49% of patients. FFRCT, visual CTP and TPR analysis was feasible in 96%, 92% and 92% of patients respectively. Overall per-vessel sensitivity, specificity and diagnostic accuracy for FFRCT were 81%, 85%, 84%, for visual CTP were 50%, 89%, 75% and for TPR were 69%, 48%, 56% respectively. Receiver-operating-characteristics curve analysis demonstrated larger per vessel area-under-curve (AUC) for FFRCT (0.89) compared with visual CTP (0.70; p < 0.001), TPR (0.58; p < 0.001) and CTA (0.70; p = 0.0007); AUC for CTA + FFRCT (0.91) was higher than CTA + visual CTP (0.77, p = 0.008) and CTA + TPR (0.74, p < 0.001). Per-patient AUC for FFRCT (0.90) was higher than visual CTP (0.69; p = 0.0016), TPR (0.56; p < 0.0001) and CTA (0.68; p = 0.001). Based on this selected cohort of patients FFRCT is superior to visually and semi-quantitatively assessed static rest/stress CTP in detecting haemodynamically-significant coronary stenosis as determined on invasive FFR.