Dobutamine effects on systolic and diastolic left ventricular long-axis excursion and timing - significance for the interpretation of s' and e'.

BACKGROUND: Dobutamine effects on the relationships of the peak velocity of left ventricular (LV) long-axis systolic motion (s') with systolic excursion (SExc), systolic duration (SDur) and heart rate, of LV long-axis early diastolic excursion (EDExc) with SExc, and of the peak velocity of LV long-axis early diastolic motion (e') with EDExc, early diastolic duration (EDDur) and isovolumic relaxation time (IVRT') are unknown. METHODS: Two groups of adult subjects, one young and healthy (n = 10), and one with impaired LV long-axis function (n = 10), were studied, with the aim of identifying consistent findings for the two groups and for the septal and lateral walls. Dobutamine was infused at doses of 5 and 10 µg/kg/min. The relationships between tissue Doppler imaging (TDI) variables acquired before and during dobutamine infusion were analysed using mixed effect multivariate regression modelling. RESULTS: In both groups, heart rate increased and SDur decreased during dobutamine infusion, and there were independent inverse correlations of SDur with heart rate and dobutamine dose. In contrast, there was no change in EDDur during dobutamine infusion, and no consistent changes in IVRT' independent of heart rate. s' was positively correlated with SExc and inversely correlated with SDur, and there were positive correlations between EDExc and SExc and between e' and EDExc. CONCLUSION: Dobutamine increases s' due to effects on both systolic excursion and duration and it increases e' due to the associated increases in systolic and early diastolic excursion. A lack of effect on diastolic times does not support the presence of a lusitropic effect of dobutamine.

Left ventricular contractile reserve as a determinant of adverse clinical outcomes: a systematic review.

An abnormal left ventricular contractile reserve is often seen in patients undergoing stress echocardiogram and may indicate the presence of obstructive coronary artery disease. The techniques and indexes used to identify abnormal left ventricular contractile response and its prognostic value in the absence of known causes has not been well studied. To describe the characteristics and clinical outcomes associated with an abnormal left ventricular contractile response, we performed a systematic review that identified 27 eligible studies. A diverse range of indices were utilised to measure left ventricular contractile reserve, most commonly Δleft ventricular ejection fraction in 11 studies. Dobutamine stress echocardiogram was the most commonly performed modality (19 studies) followed by exercise stress echocardiogram (4 studies), dipyridamole stress echocardiogram (2 studies), invasive hemodynamic measurement (1 study) and dobutamine stress magnetic resonance imaging (1 study). All but one study demonstrated a significant association between the absence of left ventricular contractile reserve and increased rate of cardiovascular events, cardiac death and all-cause mortality.

Prosthesis Geometrical Predictors of Leaflet Thrombosis Following Transcatheter Aortic Valve Replacement With Intra-Annular Prostheses.

OBJECTIVE: To determine the association between prosthesis geometry with leaflet thrombosis (LT). BACKGROUND: Leaflet thrombosis following transcatheter aortic valve replacement (TAVR) is a recognised entity. The association between prosthesis geometry with LT is unclear but maybe a potential modifiable factor in its prevention. METHODS: Patients who received an intra-annular TAVR prosthesis and were prospectively planned to undergo post-procedural computed tomography (CT) imaging were included. Leaflet thrombosis was defined as at least 50% restricted leaflet motion on CT. Prosthesis expansion and eccentricity was measured at prosthesis inflow, annulus and outflow levels. Prosthesis misalignment was defined as the average angle deviation between native and prosthesis leaflet commissure, greater than 30°. RESULTS: Prevalence of LT was 13.7% in 117 patients. None of the patients with LT were on anticoagulation therapy. Patients with LT had reduced prosthesis annular expansion (89.4±5.2% vs 97.0±4.4%, p<0.01), greater prosthesis misalignment (81.3% vs 48.5%, p=0.02) and deeper implants (6.3±1.7 mm vs 4.3±1.5 mm, p<0.01). Threshold for the presence of LT on ROC analysis was an implant depth of 5.7 mm (AUC [area under curve]=0.81). Independent predictors of LT were annular under-expansion (Odds ratio [OR] 1.4, 95% confidence interval [CI] 1.2-1.7, p=0.03) prosthesis misalignment (OR 6.8, 95%CI 1.1-45.5, p=0.04) and implant depth (OR 1.9, 95%CI 1.1-3.2, p=0.03). Anticoagulation therapy was a protective factor (OR 0.2; 95%CI 0.1-0.4, p<0.01). CONCLUSION: Geometrical predictors of LT post intra-annular TAVR were reduced prosthesis expansion at the annular level, lower implant depth and greater prosthesis misalignment. These factors may be important considerations during procedural planning for TAVR.

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.

Clinical predictors and sequelae of computed tomography defined leaflet thrombosis following transcatheter aortic valve replacement at medium-term follow-up.

BACKGROUND: The clinical predictors and sequelae of leaflet thrombosis (LT) following transcatheter aortic valve replacement (TAVR) is still unclear. Therefore, our aim was to determine the clinical predictors and sequelae at mid-term follow-up of computed tomography (CT)-defined LT following TAVR. METHODS AND RESULTS: We performed a prospective evaluation with a 320-multislice CT following TAVR for the presence of LT, defined as hypo-attenuated leaflet thickening (HALT). Four-dimensional CT image-rendering was performed to determine the presence of reduced leaflet motion (RELM). 172 patients [89 (51.7%) male, mean age 82.8 ± 5.7 years] treated with commercially available TAVR device (Lotus 54%, CoreValve 32% and Sapien 3 14%) were included, with median CT-scan at 6.0 weeks post-TAVR. Prevalence of HALT was 14.0% (24 cases) and RELM was 9.8% (17 cases). On multivariate analysis, patients with HALT were less prescribed oral anticoagulation (OAC) (OR 9.9), received larger TAVR prostheses (OR 5.7) and higher rates of moderate-severe para-valvular regurgitation (PVR) (OR 16.3). There was no difference in clinical outcomes at a median follow-up of 2.3 years. Patients with RELM had significantly higher transvalvular gradients after discharge when compared to those without RELM. CONCLUSIONS: Absence of OAC, large TAVR prostheses and moderate-severe PVR were predictors for LT. Transvalvular gradients were higher in patients that developed RELM but not HALT. Further studies are warranted to determine the long-term impact of LT on TAVR durability. Prevalence of different sub-types of CT-defined LT (HALT and RELM) and the clinical predictors of developing LT following TAVR. CT computed tomography, HALT hypo-attenuated leaflet thickening, LT leaflet thrombosis, RELM reduced leaflet motion, TAVR transcatheter aortic valve replacement.

A Randomized Trial on the Effect of Phosphate Reduction on Vascular End Points in CKD (IMPROVE-CKD).

BACKGROUND: Hyperphosphatemia is associated with increased fibroblast growth factor 23 (FGF23), arterial calcification, and cardiovascular mortality. Effects of phosphate-lowering medication on vascular calcification and arterial stiffness in CKD remain uncertain. METHODS: To assess the effects of non-calcium-based phosphate binders on intermediate cardiovascular markers, we conducted a multicenter, double-blind trial, randomizing 278 participants with stage 3b or 4 CKD and serum phosphate >1.00 mmol/L (3.10 mg/dl) to 500 mg lanthanum carbonate or matched placebo thrice daily for 96 weeks. We analyzed the primary outcome, carotid-femoral pulse wave velocity, using a linear mixed effects model for repeated measures. Secondary outcomes included abdominal aortic calcification and serum and urine markers of mineral metabolism. RESULTS: A total of 138 participants received lanthanum and 140 received placebo (mean age 63.1 years; 69% male, 64% White). Mean eGFR was 26.6 ml/min per 1.73 m2; 45% of participants had diabetes and 32% had cardiovascular disease. Mean serum phosphate was 1.25 mmol/L (3.87 mg/dl), mean pulse wave velocity was 10.8 m/s, and 81.3% had abdominal aortic calcification at baseline. At 96 weeks, pulse wave velocity did not differ significantly between groups, nor did abdominal aortic calcification, serum phosphate, parathyroid hormone, FGF23, and 24-hour urinary phosphate. Serious adverse events occurred in 63 (46%) participants prescribed lanthanum and 66 (47%) prescribed placebo. Although recruitment to target was not achieved, additional analysis suggested this was unlikely to have significantly affected the principle findings. CONCLUSIONS: In patients with stage 3b/4 CKD, treatment with lanthanum over 96 weeks did not affect arterial stiffness or aortic calcification compared with placebo. These findings do not support the role of intestinal phosphate binders to reduce cardiovascular risk in patients with CKD who have normophosphatemia. CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER: Australian Clinical Trials Registry, ACTRN12610000650099.

Off- vs. On-Pump Coronary Artery Bypass Grafting Long-Term Survival is Driven by Incompleteness of Revascularisation.

BACKGROUND: Off-pump coronary artery bypass grafting (CABG) negates the requirement for extracorporeal circulation used with the traditional on-pump approach. However, off-pump CABG is technically more challenging and may theoretically lead to less complete revascularisation. Recent data suggests a prognostic benefit for traditional on-pump CABG, but the mechanism for this remains unclear. We hypothesised that the inferior outcomes with off-pump CABG could be driven by the need for repeat revascularisation, with this benefit only becoming clear at long-term follow-up. We therefore evaluated short, medium and long-term outcomes of patients undergoing revascularisation with on vs. off-pump CABG. METHODS: Electronic databases were searched to identify suitable randomised controlled trials enrolling ≥100 patients in each arm. Clinical outcomes were extracted at 30-days, 12-months or >4years. The primary outcome was long-term all-cause death, while secondary outcomes included 30-day, 12-month and >4-year cardiac death, stroke, myocardial infarction or revascularisation. RESULTS: Thirteen (13) studies comprising 13,234 patients were included. Off-pump CABG was associated with an increased risk of all-cause death (Odds Ratio [OR] 1.18, 95% confidence interval [CI] 1.02-1.32, p=0.01) and repeat bypass surgery (OR 2.57, 95%CI 1.23-5.39, p=0.01) at long-term follow-up. A significant, increased requirement for revascularisation in off-pump was seen at 12-month follow-up (OR 1.59, 95%CI 1.09-2.33, p=0.02). No differences were noted between groups at 30-days, 12-months and >4years for myocardial infarction or stroke. CONCLUSIONS: Off-pump CABG is associated with significantly higher rates of all-cause mortality rate at long-term follow-up. These outcomes demonstrate a temporal relationship that may be driven by a greater requirement for repeat revascularisation at 1- and 5-year follow-up. STUDY REGISTRATION: CRD42018102019 (PROSPERO).

Quantitative and Qualitative Coronary Plaque Assessment Using Computed Tomography Coronary Angiography: A Comparison With Intravascular Ultrasound.

BACKGROUND: To compare computed tomography coronary angiography (CTCA) with intravascular ultrasound (IVUS) in quantitative and qualitative plaque assessment. METHODS: Patients who underwent IVUS and CTCA within 3 months for suspected coronary artery disease were retrospectively studied. Plaque volumes on CTCA were quantified manually and with automated-software and were compared to IVUS. High-risk plaque features were compared between CTCA and IVUS. RESULTS: There were 769 slices in 32 vessels (27 patients). Manual plaque quantification on CTCA was comparable to IVUS per slice (mean difference of 0.06±0.07, p=0.44; Bland-Altman 95% limits of agreement -2.19-2.08 mm3, bias of -0.06mm3) and per vessel (3.1mm3 ± -2.85mm3, p=0.92). In contrast, there was significant difference between automated-software and IVUS per slice (2.3±0.09mm3, p<0.001; 95% LoA -6.78 to 2.25mm3, bias of -2.2mm3) and per vessel (33.04±10.3 mm3, p<0.01). The sensitivity, specificity, positive and negative predictive value of CTCA to detect plaques that had features of echo-attenuation on IVUS was 93.3%, 99.6%, 93.3% and 99.6% respectively. The association of ≥2 high-risk plaque features on CTCA with echo attenuation (EA) plaque features on IVUS was excellent (86.7%, 99.6%, 92.9% and 99.2%). In comparison, the association of high-risk plaque features on CTCA and plaques with echo-lucency on IVUS was only modest. CONCLUSION: Plaque volume quantification by manual CTCA method is accurate when compared to IVUS. The presence of at least two high-risk plaque features on CTCA is associated with plaque features of echo attenuation on IVUS.

Application of the DILEMMA score to improve lesion selection for invasive physiological assessment.

OBJECTIVES: We sought to assess the validity of the DILEMMA score against instantaneous wave-free ratio (iFR) and evaluate its utility in rationalizing the number of patients referred for invasive physiological assessment. BACKGROUND: The DILEMMA score is a validated angiographic scoring tool incorporating minimal lumen diameter, lesion length and subtended myocardial area that has been shown to predict the functional significance of lesions as assessed by fractional flow reserve (FFR). METHODS: Patients in the DEFINE-FLAIR study who had coronary stenosis of intermediate severity were randomized to either FFR or iFR. DILEMMA score was calculated retrospectively on a subset of this cohort by operators blinded to FFR or iFR values. RESULTS: Three hundred and forty-six lesions (181 assessed by FFR; 165 by iFR) from 259 patients (mean age 66.0 years, 79% male) were included. A DILEMMA score ≤ 2 had a negative predictive value of 96.3% and 95.7% for identifying lesions with FFR >0.80 and iFR >0.89, respectively. A DILEMMA score ≥ 9 had a positive predictive value of 88.9% and 100% for identifying lesions with FFR ≤0.80 and iFR ≤0.89, respectively. The receiver operating characteristic area under the curve values for DILEMMA score to predict FFR ≤0.80 and iFR ≤0.89 were 0.83 (95% CI 0.77-0.90) and 0.82 (0.75-0.89) respectively. A DILEMMA score ≤ 2 or ≥9 occurred in 172 of the 346 lesions (49.7%). CONCLUSIONS: Using DILEMMA score in patients with coronary stenosis of intermediate severity may reduce the need for pressure wire use, offering potential cost-savings and minimizing the risks associated with invasive physiological lesion assessment.

The prevalence of computed tomography-defined leaflet thrombosis in intra- versus supra-annular transcatheter aortic valve prostheses.

INTRODUCTION: Leaflet thrombosis (LT) defined by computed tomography (CT) following transcatheter aortic valve replacement (TAVR) has been shown to increase cerebrovascular events. The neo-sinus plays an important role in the development of LT. Intra-annular valves (IAV) have a larger neo-sinus when compared to supra-annular valves (SAV), and has been associated with larger thrombus burden. The prevalence of LT with IAV and SAV in a larger, diverse cohort is unknown. METHODS: We performed a systematic review to assess the prevalence of LT in IAV versus SAV TAVR prostheses. Inclusion criteria were (1) reported CT-defined LT following TAVR, (2) comparison between LT and non-LT cohort, (3) separate registry/database, and (4) fully published status. A total of 2,013 citations were reviewed and 7 studies were included. RESULTS: Overall, 1,644 patients were included from 7 observational studies and the prevalence of LT following TAVR was 12.8%. The Portico valve system (IAV) had the highest prevalence of LT with 35.2%, followed by Symetis Acurate Neo (SAV) at 15.4% and the Lotus valve system (IAV) at 14.5%. LT occurred more frequently in IAV than SAV (13.5% vs. 7%, P = 0.02). Subanalysis of IAV versus SAV with the exclusion of the Portico valve was performed to ensure results were not influenced by this valve system and revealed IAV still had higher rates of LT (12.1% vs. 7%, P = 0.05). CONCLUSION: In summary, IAV prostheses appear to be associated with higher rates of LT when compared with SAV.

Polymer-free versus permanent polymer-coated drug eluting stents for the treatment of coronary artery disease: A meta-analysis of randomized trials.

BACKGROUND: Polymer-free drug eluting stents (PF-DES) were developed, in part, to overcome risk of late ischemic events observed with permanent polymer-coated DES (PP-DES). However, trial results are inconsistent with longer-term safety and efficacy of PF-DES remaining unknown. We performed a meta-analysis of randomized trials assessing outcomes of patients receiving PF-DES versus PP-DES for treatment of coronary artery disease (CAD). METHODS: Electronic searches were performed for randomized trials comparing outcomes between PF-DES and PP-DES. Trials reporting major adverse cardiovascular events (MACE), myocardial infarction (MI), stent thrombosis (ST), all-cause death, target lesion/vessel revascularization (TLR/TVR), and late lumen loss (LLL) were included. Analyses were performed at longest follow-up and landmarked beyond 1-year. RESULTS: Twelve trials (6,943 patients) were included. There was no significant difference in MACE between PF-DES and PP-DES at longest follow-up (Odds Ratio [OR] 0.96, 95%CI 0.85-1.10, P = 0.59) or landmark analysis beyond 1-year (OR 0.96, 95%CI 0.76-1.20, P = 0.70). Although PF-DES were associated with a significant reduction in all-cause death (OR 0.85, 95%CI 0.72-1.00, P < 0.05), this effect was not present on landmark analysis beyond 1-year (OR 0.89, 95%CI 0.73-1.10, P = 0.30). There were no differences observed for MI (OR 1.00, 95%CI 0.77-1.28, P = 0.99) or ST (OR 0.95, 95%CI 0.54-1.68, P = 0.86), with similar efficacy outcomes including TVR (OR 1.07, 95%CI 0.91-1.26, P = 0.42), TLR (OR 1.03, 95%CI 0.88-1.21, P = 0.68) and angiographic LLL (pooled mean difference 0.01 mm, 95%CI -0.08 to 0.11, P = 0.76). CONCLUSIONS: PF-DES are as safe and efficacious as PP-DES for the treatment of patients with CAD, but do not significantly reduce late ischemic complications.

Subclinical Leaflet Thrombosis in Transcatheter Aortic Valve Replacement Detected by Multidetector Computed Tomography　- A Review of Current Evidence.

Subclinical leaflet thrombosis (SLT) following transcatheter aortic valve replacement (TAVR) has been increasingly recognized. SLT has the hallmark features of hypo-attenuated leaflet thickening (HALT) on multidetector computed tomography (MDCT), which may result in hypoattenuation affecting motion (HAM). The actual prevalence of this condition is uncertain, with limited observational registries. SLT has caught the attention of the cardiovascular community because of concerns regarding its clinical sequelae, specifically the potential increased incidence of cerebrovascular events. There are available, albeit sparse, data to suggest that when left untreated, SLT may lead to valve deterioration with potential hemodynamic compromise and potentially clinically overt prostheses thrombosis. Some clinicians have opted to treat patients with SLT with anticoagulation. Although anticoagulation may be a rational treatment option, little data exist on the safety and efficacy of this treatment. This is particularly important considering TAVR patients also have higher bleeding risk than the standard population. In this review, we aim to summarize the current evidence on SLT, explore its pathophysiological mechanism, discuss the current treatment options and future trials that may clarify the optimal antithrombotic strategies of SLT.

Heart Failure and Exercise: A Narrative Review of the Role of Self-Efficacy.

Chronic heart failure (CHF) is a common, debilitating condition associated with significant health and economic burden. CHF management is multidisciplinary, however, achieving better health relies on a collaborative effort and patient engagement in self-care. Despite the importance of self-care in CHF, many patients have poor adherence to their medical and lifestyle regimens, in particular with regards to engaging in physical exercise. The patient's confidence in their ability, otherwise known as self-efficacy, is an important determinant of CHF health outcomes, most likely due to its effect on the uptake of CHF self-care activities especially exercise initiation and maintenance. Self-efficacy is responsive to experience such as exercise training, however the critical components of exercise interventions to improve self-efficacy have yet to be determined. This narrative review provides an overview of the role of self-efficacy in exercise adherence in CHF.

Retrospective Cohort Study Examining Reduced Intensity and Duration of Anticoagulant and Antiplatelet Therapy Following Left Atrial Appendage Occlusion with the WATCHMAN Device.

BACKGROUND: Anticoagulant and antiplatelet therapy are recommended following WATCHMAN implantation (45 days and 6 months) to reduce the risk of embolic events. These patients are often also at high risk of recurrent bleeding complications. We aimed to assess the safety of reduced duration of treatment with anticoagulant and antiplatelet therapy in the early post implant period. METHODS: This was a retrospective cohort study assessing the duration of antiplatelet and anticoagulant therapy in 47 consecutive patients following WATCHMAN implant. The primary outcome was rate of major bleeding, stroke and systemic embolic complications. The secondary endpoints were rate of device thrombus and peri-device leak >4mm as assessed by transoesophogeal echocardiography. RESULTS: Forty-seven patients were followed up for a mean of 2.4+/-1.7 years (111.4 total patient-years). The rate of stroke was 1.8/100 patient-years (two events) and the rate of major bleeding complication was 8.9/100 patient-years. Three patients had peri-device leak >4mm and no patients had device thrombus visualised. 70.2% of patients had discontinued anticoagulation at 45 days, 89.4% had discontinued dual antiplatelet therapy at 90 days. Seven patients were not on any form of anticoagulant or antiplatelet at five months. Comparison of probability of survival free from stroke by time of cessation of anticoagulant and antiplatelet therapy demonstrated no significant differences (p-value for log rank test 0.238 and 0.820). CONCLUSION: Following WATCHMAN implant shortened periods of anticoagulants and antiplatelets may be considered, particularly in the context of high bleeding risk.

Optical Coherence Tomography Guided Percutaneous Coronary Intervention.

Optical coherence tomography (OCT) is an increasingly available intracoronary imaging modality that provides high-resolution imaging of coronary arteries. Its fundamental reliance on the emission and reflection of light enables rapid data acquisition without compromise of image resolution. As such, OCT can inform operators planning percutaneous coronary intervention (PCI) by accurately defining luminal geometry and detailing plaque composition. Following PCI, OCT imaging delivers a thorough assessment of the treated arterial segment and can identify specific features not always visible on alternate imaging modalities, including stent edge-related dissection, plaque tissue prolapse, incomplete stent apposition and the presence of intra-coronary thrombus. Clinical trials highlight that procedural strategy is frequently altered based on OCT findings, while concerns over final stent dimensions have been mitigated through use of a sizing protocol based on external elastic lamina dimensions in the reference arterial segment. Randomised trials are now warranted to definitively ascertain whether OCT-guidance improves clinical outcomes when utilised during PCI.

Diagnostic Performance of Transluminal Attenuation Gradient and Noninvasive Fractional Flow Reserve Derived from 320-Detector Row CT Angiography to Diagnose Hemodynamically Significant Coronary Stenosis: An NXT Substudy.

PURPOSE: To compare the diagnostic performance of 320-detector row computed tomography (CT) coronary angiography-derived computed fractional flow reserve (FFR; FFRCT), transluminal attenuation gradient (TAG; TAG320), and CT coronary angiography alone to diagnose hemodynamically significant stenosis as determined by invasive FFR. MATERIALS AND METHODS: This substudy of the prospective NXT study (no. NCT01757678) was approved by each participating institution's review board, and informed consent was obtained from all participants. Fifty-one consecutive patients who underwent 320-detector row CT coronary angiographic examination and invasive coronary angiography with FFR measurement were included. Independent core laboratories determined coronary artery disease severity by using CT coronary angiography, TAG320, FFRCT, and FFR. TAG320 is defined as the linear regression coefficient between luminal attenuation and axial distance from the coronary ostium. FFRCT was computed from CT coronary angiography data by using computational fluid dynamics technology. Diagnostic performance was evaluated and compared on a per-vessel basis by the area under the receiver operating characteristic (ROC) curve (AUC). RESULTS: Among 82 vessels, 24 lesions (29%) had ischemia by FFR (FFR ≤ 0.80). FFRCT exhibited a stronger correlation with invasive FFR compared with TAG320 (Spearman ρ, 0.78 vs 0.47, respectively). Overall per-vessel accuracy, sensitivity, specificity, and positive and negative predictive values for TAG320 (<15.37) were 78%, 58%, 86%, 64%, and 83%, respectively; and those of FFRCT were 83%, 92%, 79%, 65%, and 96%, respectively. ROC curve analysis showed a significantly larger AUC for FFRCT (0.93) compared with that for TAG320 (0.72; P = .003) and CT coronary angiography alone (0.68; P = .008). CONCLUSION: FFRCT computed from 320-detector row CT coronary angiography provides better diagnostic performance for the diagnosis of hemodynamically significant coronary stenoses compared with CT coronary angiography and TAG320.

The ASLA Score: A CT Angiographic Index to Predict Functionally Significant Coronary Stenoses in Lesions with Intermediate Severity-Diagnostic Accuracy.

PURPOSE: To identify computed tomographic (CT) coronary indexes independently associated with a fractional flow reserve (FFR) of 0.8 or less, to derive a score that combines CT indexes most predictive of an FFR of 0.8 or less, and to evaluate the diagnostic accuracy of the score in predicting an FFR of 0.8 or less. MATERIALS AND METHODS: This retrospective study had institutional review board approval and waiver of the need to obtain informed consent. Consecutive patients who underwent CT coronary angiography and FFR assessment with one or more discrete lesion(s) of intermediate (30%-70%) severity at CT were included. Quantitative CT measurements were performed by using dedicated software. The CT indexes evaluated included the following: plaque burden, minimal luminal area and diameter, stenosis diameter, area of stenosis, lesion length, remodeling index, plaque morphology, calcification severity, and the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) score, which approximates the size of the myocardium subtended by a lesion. By using covariates independently associated with an FFR of 0.8 or less, a score was determined on the basis of modified Akaike information criteria, and the C statistics of individual and combined indexes were compared. RESULTS: Eighty-five patients (mean age, 64.2 years; range, 48-88 years; 65.9% men; 124 lesions; 38 lesions with an FFR ≤ 0.8) were included. Area of stenosis, lesion length, and APPROACH score were the strongest predictors of an FFR of 0.8 or less and were used to derive the ASLA score. The optimism-adjusted Harrell C statistic for the combined score was 0.82, which was superior to that for area of stenosis (0.74), lesion length (0.75), and the APPROACH score (0.71) (P < .001 for trend). The corresponding incremental discrimination improvement indexes were 0.17, 0.11, and 0.19, respectively (P < .001 for all), suggesting that the score improves reclassification compared with any one angiographic index. The average time required for score derivation was 102.6 seconds. CONCLUSION: The ASLA score, which accounts for CT-derived area of stenosis, lesion length, and APPROACH score, may conveniently improve the prediction, beyond individual indexes, of functionally significant intermediate coronary lesions.

A novel coronary angiography index (DILEMMA score) for prediction of functionally significant coronary artery stenoses assessed by fractional flow reserve: A novel coronary angiography index.

BACKGROUND: Angiographic evaluation of diameter stenosis has modest predictive value for functionally significant coronary artery stenoses as assessed by fractional flow reserve (FFR). Lesion length and assessment of area of myocardium at risk (Bypass Angioplasty Revascularization Investigation [BARI] Myocardial Jeopardy Index [MJI]) subtended by the stenotic coronary arteries are also predictors of functionally significant coronary artery stenoses. We sort to assess the diagnostic accuracy of DILEMMA score, which combines minimal lumen diameter (MLD), lesion length, and BARI MJI in prediction of significantly reduced FFR (≤0.8). METHODS: We assessed patients who underwent coronary angiography and FFR. Lesion length and MLD were assessed by quantitative coronary angiography. Estimation of area of myocardium at risk subtended by coronary stenoses was performed using the BARI MJI. RESULTS: A total of 296 patients (age 64 ± 10.6 years, 68% male, 497 vessels) were included. DILEMMA score was significantly higher in vessels with significant FFR, 6.09 ± 3.23 versus 3.84 ± 2.99 (P < .001). In the derivation cohort, the optimism-adjusted Harrell c statistic for DILEMMA score was 0.82 compared with 0.76 for BARI MJI, 0.75 for lesion length, and 0.7 for MLD. In the validation cohort, the c-statistic for DILEMMA score, BARI MJI, lesion length, and MLD was 0.88, 0.77, 0.81, and 0.72, respectively. The DILEMMA score was a better predictor of FFR ≤0.8 compared with MLD, lesion length, and BARI MJI individually (P < .001, P < .02, and P < .045, respectively) on Bonferroni-adjusted pairwise comparison. CONCLUSIONS: DILEMMA score, taking into account MLD, lesion length, and BARI MJI, may have incremental predictive value beyond the individual indices alone for detecting functionally significant coronary artery stenoses.

Long-term outcome after CT angiography in patients with possible acute coronary syndrome.

PURPOSE: To assess the long-term outcome and hospital readmission rate associated with a computed tomographic (CT) angiography-guided strategy used to examine patients who present to the emergency department (ED) with symptoms of possible acute coronary syndrome (ACS). MATERIALS AND METHODS: The study was approved by the institutional review board, and all patients provided written informed consent. A total of 585 consecutive patients (mean age, 58 years ± 11 [standard deviation]; 58% were male) with ischemic-type chest pain and low to intermediate risk for ACS were evaluated prospectively. Patients underwent coronary CT angiography after single or serial troponin I (TnI) measurement, depending on time of presentation to the ED. Subsequent care was determined with CT angiography findings: Patients without plaque and patients with nonobstructive plaque and at most mild to moderate stenosis (<40% luminal narrowing) were discharged without further investigation. Patients with moderate stenosis (40%-70% narrowing) were discharged and referred for outpatient stress echocardiography. Patients with severe stenosis (>70% narrowing) were admitted. Discharged patients were contacted and their medical records were reviewed to determine rates of death, ACS, revascularization, and hospital admission. By using binomial distribution, Clopper-Pearson confidence intervals (CIs) were calculated for outcome data. RESULTS: Coronary CT angiography findings were as follows: A total of 196 patients (34%) had no coronary plaque or stenosis, 288 (49%) had nonobstructive plaque, 22 (4%) had moderate stenosis, and 79 (13%) had severe stenosis. At median 47.4-month follow-up (range, 24-57 months) of the 506 discharged patients, five (1%; 95% CI: 0.4%, 2.3%) had been readmitted for chest pain; there were no instances of coronary revascularization, ACS, or death (0% for all; 95% CI: 0%, 0.7%). Follow-up was 100% complete. CONCLUSION: Use of a CT angiography-guided strategy to investigate patients with low to intermediate risk of ACS who present to the ED with chest pain is safe at long-term follow-up, including patients discharged after single TnI measurement.