Endovascular Transvenous versus Open Femoropopliteal Bypass.

Background and Objectives: Lower extremity arterial disease is one of the most prevalent manifestations of atherosclerosis. The results from numerous studies regarding the best revascularization method of an occluded superficial femoral artery have been conflicting. The aim of this study was to compare the patency of transvenous endovascular with open femoropopliteal bypass, both with vein and prosthetic grafts. To our knowledge, a direct patency comparison between transvenous endovascular and open femoropopliteal bypass has not been published. This could help elucidate which method is preferable and in which cases. Materials and Methods: Patients with complex TASC-C and D SFA lesions were offered endovascular transvenous or open bypass. A total of 384 consecutive patients with PAD requiring surgical treatment were evaluated for inclusion in this study. Three-year follow-up data were collected for 52 endovascular procedures, 80 prosthetic grafts, and 44 venous bypass surgeries. Bypass patency was investigated by Duplex US every 6 months. Kaplan-Meier plots were used to analyze primary, primary-assisted, and secondary patency for endovascular transvenous, autovenous, and prosthetic bypasses. Results: Primary, primary-assisted, and secondary patency in venous group at 3 years was 70.5%, 77.3%, and 77.3%, respectively. In the endovascular transvenous group, primary, primary-assisted, and secondary patency at 3 years was 46.2%, 69.2%, and 76.9%, respectively. The lowest patency rates at 3 years were noted in the prosthetic graft group with 22.5% primary, 26.6% primary-assisted, and 28.2% secondary patency. Conclusions: The saphenous vein is the best graft to perform in above-the-knee femoropopliteal bypass. Transvenous endovascular bypass is a viable option with comparable primary-assisted and secondary patency. Primary patency is substantially lower for endovascular transvenous compared to venous bypass. Patients treated with endovascular transvenous bypass will require a significant number of secondary procedures to provide optimal patency. Prosthetic grafts should only be used if no other option for bypass is available.

Ischemia-Guided Coronary Revascularization Following Lower-Extremity Revascularization Improves 5-Year Survival of Patients With Chronic Limb-Threatening Ischemia.

PURPOSE: To determine whether diagnosis of asymptomatic (silent) coronary ischemia using coronary computed tomography (CT)-derived fractional flow reserve (FFRCT) together with targeted coronary revascularization of ischemia-producing coronary lesions following lower-extremity revascularization can reduce adverse cardiac events and improve long-term survival of patients with chronic limb-threatening ischemia (CLTI). MATERIALS AND METHODS: Prospective cohort study of CLTI patients with no cardiac history or symptoms undergoing elective lower-extremity revascularization. Patients with pre-operative coronary computed tomography angiography (CTA) and FFRCT evaluation with selective post-operative coronary revascularization (FFRCT group) were compared with patients with standard pre-operative evaluation and no post-operative coronary revascularization (control group). Lesion-specific coronary ischemia was defined as FFRCT≤0.80 distal to a coronary stenosis with FFRCT≤0.75 indicating severe ischemia. Endpoints included all-cause death, cardiac death, myocardial infarction (MI) and major adverse cardiovascular (CV) events (MACE=CV death, MI, stroke, or unplanned coronary revascularization) during 5 year follow-up. RESULTS: In the FFRCT group (n=111), FFRCT analysis revealed asymptomatic (silent) coronary ischemia (FFRCT≤0.80) in 69% of patients, with severe ischemia (FFRCT≤0.75) in 58%, left main ischemia in 8%, and multivessel ischemia in 40% of patients. The status of coronary ischemia in the control group (n=120) was unknown. Following lower-extremity revascularization, 42% of patients in FFRCT had elective coronary revascularization with no elective revascularization in controls. Both groups received guideline-directed medical therapy. During 5 year follow-up, compared with control, the FFRCT group had fewer all-cause deaths (24% vs 47%, hazard ratio [HR]=0.43 [95% confidence interval [CI]=0.27-0.69], p<0.001), fewer cardiac deaths (5% vs 26%, HR=0.18 [95% CI=0.07-0.45], p<0.001), fewer MIs (7% vs 28%, HR=0.21 [95% CI=0.10-0.47], p<0.001), and fewer MACE events (14% vs 39%, HR=0.28 [95% CI=0.15-0.51], p<0.001). CONCLUSIONS: Ischemia-guided coronary revascularization of CLTI patients with asymptomatic (silent) coronary ischemia following lower-extremity revascularization resulted in more than 2-fold reduction in all-cause death, cardiac death, MI, and MACE with improved 5 year survival compared with patients with standard cardiac evaluation and care (76% vs 53%, p<0.001). CLINICAL IMPACT: Silent coronary ischemia in patients with chronic limb-threatening ischemia (CLTI) is common even in the absence of cardiac history or symptoms. FFRCT is a convenient tool to diagnose silent coronary ischemia perioperatively. Our data suggest that post-surgery elective FFRCT-guided coronary revascularization reduces adverse cardiac events and improves long-term survival in this very-high risk patient group. Randomized study is warranted to finally test this concept.

Diagnosis and treatment of ischemia-producing coronary stenoses improves 5-year survival of patients undergoing major vascular surgery.

OBJECTIVE: Patients undergoing vascular surgery procedures have poor long-term survival due to coexisting coronary artery disease (CAD), which is often asymptomatic, undiagnosed, and undertreated. We sought to determine whether preoperative diagnosis of asymptomatic (silent) coronary ischemia using coronary computed tomography (CT)-derived fractional flow reserve (FFRCT) together with postoperative ischemia-targeted coronary revascularization can reduce adverse cardiac events and improve long-term survival following major vascular surgery METHODS: In this observational cohort study of 522 patients with no known CAD undergoing elective carotid, peripheral, or aneurysm surgery we compared two groups of patients. Group I included 288 patients enrolled in a prospective Institutional Review Board-approved study of preoperative coronary CT angiography (CTA) and FFRCT testing to detect silent coronary ischemia with selective postoperative coronary revascularization in addition to best medical therapy (BMT) (FFRCT guided), and Group II included 234 matched controls with standard preoperative cardiac evaluation and postoperative BMT alone with no elective coronary revascularization (Usual Care). In the FFRCT group, lesion-specific coronary ischemia was defined as FFRCT ≤0.80 distal to a coronary stenosis, with severe ischemia defined as FFRCT ≤0.75. Results were available for patient management decisions. Endpoints included all-cause death, cardiovascular death, myocardial infarction (MI), and major adverse cardiovascular events (MACE [death, MI, or stroke]) during 5-year follow-up. RESULTS: The two groups were similar in age, gender, and comorbidities. In FFRCT, 65% of patients had asymptomatic lesion-specific coronary ischemia, with severe ischemia in 52%, multivessel ischemia in 36% and left main ischemia in 8%. The status of coronary ischemia was unknown in Usual Care. Vascular surgery was performed as planned in both cohorts with no difference in 30-day mortality. In FFRCT, elective ischemia-targeted coronary revascularization was performed in 103 patients 1 to 3 months following surgery. Usual Care had no elective postoperative coronary revascularizations. At 5 years, compared with Usual Care, FFRCT guided had fewer all-cause deaths (16% vs 36%; hazard ratio [HR], 0.37; 95% confidence interval [CI], 0.22-0.60; P < .001), fewer cardiovascular deaths (4% vs 21%; HR, 0.11; 95% CI, 0.04-0.33; P < .001), fewer MIs (4% vs 24%; HR, 0.13; 95% CI, 0.05-0.33; P < .001), and fewer MACE (20% vs 47%; HR, 0.36; 95% CI, 0.23-0.56; P < .001). Five-year survival was 84% in FFRCT compared with 64% in Usual Care (P < .001). CONCLUSIONS: Diagnosis of silent coronary ischemia with ischemia-targeted coronary revascularization in addition to BMT following major vascular surgery was associated with fewer adverse cardiovascular events and improved 5-year survival compared with patients treated with BMT alone as per current guidelines.

Long-term prognostic implications of hemodynamic and plaque assessment using coronary CT angiography.

BACKGROUND AND AIMS: Hemodynamic and plaque characteristics can be analyzed using coronary CT angiography (CTA). We aimed to explore long-term prognostic implications of hemodynamic and plaque characteristics using coronary CT angiography (CTA). METHODS: Invasive fractional flow reserve (FFR) and CTA-derived FFR (FFRCT) were undertaken for 136 lesions in 78 vessels and followed-up to 10 years until December 2020. FFRCT, wall shear stress (WSS), change in FFRCT across the lesion (ΔFFRCT), total plaque volume (TPV), percent atheroma volume (PAV), and low-attenuation plaque volume (LAPV) for target lesions [L] and vessels [V] were obtained by independent core laboratories. Their collective influence was evaluated for the clinical endpoints of target vessel failure (TVF) and target lesion failure (TLF). RESULTS: During a median follow-up of 10.1 years, PAV[V] (per 10% increase, HR 2.32 [95% CI 1.11-4.86], p = 0.025), and FFRCT[V] (per 0.1 increase, HR 0.56 [95% CI 0.37-0.84], p = 0.006) were independent predictors of TVF for the per-vessel analysis, and WSS[L] (per 100 dyne/cm2 increase, HR 1.43 [1.09-1.88], p = 0.010), LAPV[L] (per 10 mm3 increase, HR 3.81 [1.16-12.5], p = 0.028), and ΔFFRCT[L] (per 0.1 increase, HR 1.39 [1.02-1.90], p = 0.040) were independent predictors of TLF for the per-lesion analysis after adjustment for clinical and lesion characteristics. The addition of both plaque and hemodynamic predictors improved the predictability for 10-year TVF and TLF of clinical and lesion characteristics (all p < 0.05). CONCLUSIONS: Vessel- and lesion-level hemodynamic characteristics, and vessel-level plaque quantity, and lesion-level plaque compositional characteristics assessed by CTA offer independent and additive long-term prognostic value.

Three-Year Patency Results following Endovascular Transvenous Femoropopliteal Bypass.

Background and Objectives: Peripheral artery disease is one of the most common vascular pathologies. There is an ongoing debate among specialists on whether open or endovascular revascularization is preferred in cases of complex superficial femoral artery (SFA) lesions. The purpose of this study was to assess patency results of a relatively new transvenous endovascular bypass device. This could add to existing evidence and aid in comparison between open and endovascular bypass. Materials and Methods: Patients with complex TASC-C and D SFA lesions who had indications for revascularization were identified. Prospective analysis of stent graft patency from 54 transvenous femoropopliteal bypass procedures was performed. Patency was assessed by Duplex ultrasound every six months. Kaplan-Meier analysis was performed to assess primary, primary-assisted, and secondary patency of transvenous bypass. Results: Following endovascular transvenous femoropopliteal bypass, 3-year graft primary, primary-assisted, and secondary patency was 43.8%, 66.3%, and 73.9%, respectively. Conclusions: Transvenous endovascular femoropopliteal bypass is a viable option for selected patients who lack adequate saphenous vein or have comorbidities that increase the risk of open femoropopliteal bypass. Strict post-operative follow-up is necessary to improve patency rates.

Coronary revascularization of patients with silent coronary ischemia may reduce the risk of myocardial infarction and cardiovascular death after carotid endarterectomy.

BACKGROUND: Major adverse cardiac events (MACEs) are the primary cause of death after carotid endarterectomy (CEA). We sought to determine whether selective coronary revascularization of CEA patients with asymptomatic coronary ischemia can reduce the risk of MACEs, myocardial infarction (MI), and cardiac death after endarterectomy compared with CEA patients receiving standard cardiac evaluation and care. METHODS: Two groups of patients with no cardiac history or symptoms undergoing elective CEA were compared. Group I: patients enrolled in a prospective study of noninvasive preoperative cardiac evaluation using coronary computed tomography (CT)-derived fractional flow reserve (FFRCT) to detect asymptomatic (silent) coronary ischemia with selective postoperative coronary revascularization. Group II: matched Control patients with standard preoperative cardiac evaluation and no postoperative coronary revascularization. Lesion-specific coronary ischemia in group I was defined as FFRCT ≤ 0.80 distal to coronary stenosis with severe ischemia defined as FFRCT ≤ 0.75. End points included MACEs, cardiac death, MI, cardiovascular (CV) death, stroke, and all-cause death through 3-year follow-up. RESULTS: Group I (n = 100) and group II (n = 100) patients were similar in age (68 vs 67 years), gender (65% vs 62% male), comorbidities, and indications for CEA (53% vs 48% symptomatic carotid stenosis). In group I, FFRCT analysis revealed lesion-specific coronary ischemia in 57% of patients, severe coronary ischemia in 44%, left main ischemia in 7%, and multivessel ischemia in 28%. The status of coronary ischemia in group II was unknown. CEA was performed without complications in both groups, and all patients received optimal postoperative medical therapy. In group I, elective coronary revascularization was performed in 33 patients (27 percutaneous coronary intervention; 6 coronary artery bypass grafting) 1 to 3 months after CEA. Group II patients had no elective coronary revascularization. During 3-year follow-up, compared with group II, group I patients had fewer MACEs (4% vs 17%, hazard ratio [HR]: 0.21 [95% confidence interval (CI): 0.07-0.63], P = .004), fewer cardiac deaths (2% vs 9%, HR: 0.20 [95% CI: 0.04-0.95], P = .030), fewer MIs (3% vs 17%, HR: 0.16 [95% CI: 0.05-0.54], P = .001), and fewer CV deaths (2% vs 12%, HR: 0.16 [95% CI: 0.004-0.07], P = .009). There were no significant differences in the rates of stroke or all-cause death. CONCLUSIONS: Preoperative diagnosis of silent coronary ischemia with selective coronary revascularization after CEA may reduce the risk of MACEs, cardiac death, MI, and CV death during 3-year follow-up compared with CEA patients receiving standard cardiac evaluation and care.

Diagnosis of silent coronary ischemia with selective coronary revascularization might improve 2-year survival of patients with critical limb-threatening ischemia.

BACKGROUND: Patients with critical limb-threatening ischemia (CLTI) have had poor long-term survival after lower extremity revascularization owing to coexistent coronary artery disease. A new cardiac diagnostic test, coronary computed tomography-derived fractional flow reserve (FFRCT), can identify patients with ischemia-producing coronary stenosis who might benefit from coronary revascularization. We sought to determine whether the diagnosis of silent coronary ischemia before limb salvage surgery with selective postoperative coronary revascularization can reduce the incidence of adverse cardiac events and improve the survival of patients with CLTI compared with standard care. METHODS: Patients with CLTI and no cardiac history or symptoms who had undergone preoperative testing to detect silent coronary ischemia with selective postoperative coronary revascularization (group I) were compared with patients with standard preoperative cardiac clearance and no elective postoperative coronary revascularization (group II). Both groups received guideline-directed medical care. Lesion-specific coronary ischemia in group I was defined as FFRCT of ≤0.80 distal to a stenosis, with severe ischemia defined as FFRCT of ≤0.75. The endpoints included all-cause death, cardiovascular (CV) death, myocardial infarction (MI), major adverse CV events (i.MACE; CV death, MI, unplanned coronary revascularization, stroke) through 2 years of follow-up. RESULTS: Groups I (n = 111) and II (n = 120) were similar in age (66 ± 9 vs 66 ± 7 years), gender (78% vs 83% men), comorbidities, and surgery performed. In group I, unsuspected, silent coronary ischemia was found in 71 of 103 patients (69%), with severe ischemia in 58% and left main coronary ischemia in 8%. Elective postoperative coronary revascularization was performed in 47 of 71 patients with silent ischemia (66%). In group II, the status of silent coronary ischemia was unknown. The median follow-up was >2 years for both groups. The 2-year outcomes for groups I and II were as follows: all-cause death, 8.1% and 20.0% (hazard ratio [HR], 0.38; 95% confidence interval [CI], 0.18-0.84; P = .016); CV death, 4.5% and 13.3% (HR, 0.32; 95% CI, 0.11-0.88; P = .028); MI, 6.3% and 17.5% (HR, 0.33; 95% CI, 0.14-0.79; P = .012); and major adverse CV events, 10.8% and 23.3% (HR, 0.44; 95% CI, 0.22-0.88; P = .021), respectively. CONCLUSIONS: The preoperative evaluation of patients with CLTI and no known coronary artery disease using coronary FFRCT revealed silent coronary ischemia in two of every three patients. Selective coronary revascularization of patients with silent coronary ischemia after recovery from limb salvage surgery resulted in fewer CV deaths and MIs and improved 2-year survival compared with patients with CLTI who had received standard cardiac evaluation and care. Prospective controlled studies are required to further define the role of FFRCT in the evaluation and treatment of patients with CLTI.

Computational medicine, present and the future: obstetrics and gynecology perspective.

Medicine is, in its essence, decision making under uncertainty; the decisions are made about tests to be performed and treatments to be administered. Traditionally, the uncertainty in decision making was handled using expertise collected by individual providers and, more recently, systematic appraisal of research in the form of evidence-based medicine. The traditional approach has been used successfully in medicine for a very long time. However, it has substantial limitations because of the complexity of the system of the human body and healthcare. The complex systems are a network of highly coupled components intensely interacting with each other. These interactions give those systems redundancy and thus robustness to failure and, at the same time, equifinality, that is, many different causative pathways leading to the same outcome. The equifinality of the complex systems of the human body and healthcare system demand the individualization of medical care, medicine, and medical decision making. Computational models excel in modeling complex systems and, consequently, enabling individualization of medical decision making and medicine. Computational models are theory- or knowledge-based models, data-driven models, or models that combine both approaches. Data are essential, although to a different degree, for computational models to successfully represent complex systems. The individualized decision making, made possible by the computational modeling of complex systems, has the potential to revolutionize the entire spectrum of medicine from individual patient care to policymaking. This approach allows applying tests and treatments to individuals who receive a net benefit from them, for whom benefits outweigh the risk, rather than treating all individuals in a population because, on average, the population benefits. Thus, the computational modeling-enabled individualization of medical decision making has the potential to both improve health outcomes and decrease the costs of healthcare.

Diagnosis and management of silent coronary ischemia in patients undergoing carotid endarterectomy.

BACKGROUND: Coronary artery disease is the primary cause of death in patients with carotid artery disease and silent ischemia is a marker for adverse coronary events. A new noninvasive cardiac diagnostic test, coronary computed tomography-derived fractional flow reserve (FFRCT) can reliably identify ischemia-producing coronary stenosis in patients with coronary artery disease and help to select patients for coronary revascularization. The purpose of this study is to determine the prevalence of silent coronary ischemia in patients undergoing carotid endarterectomy (CEA) and to evaluate the usefulness of FFRCT in selecting patients for coronary revascularization to decrease cardiac events and improve survival. METHODS: Patients with no cardiac history or symptoms admitted for elective CEA were enrolled in a prospective, open-label, institutional review board-approved study and underwent preoperative coronary computed tomography angiography (CTA) and FFRCT with results available to physicians for patient management. Lesion-specific coronary ischemia was defined as FFRCT of 0.80 or less distal to a focal coronary stenosis with an FFRCT of 0.75 or less, indicating severe ischemia. Primary end point was incidence of major adverse cardiovascular events (MACE; defined as cardiovascular death, myocardial infarction, or stroke) at 30 days and 1 year. RESULTS: Coronary CTA and FFRCT was performed in 90 CEA patients (age 67 ± 8 years; male 66%). Lesion-specific coronary ischemia was found in 51 patients (57%) with a mean FFRCT of 0.71 ± 0.14. Severe coronary ischemia was present in 39 patients (43%), 26 patients had multivessel ischemia, and 5 had left main disease. CEA was performed as scheduled in all patients with no postoperative deaths or myocardial infarctions. There were no MACE events at 30 days. After recovery from surgery, 36 patients with significant lesion-specific ischemia underwent coronary angiography with coronary revascularization (percutaneous coronary intervention or coronary artery bypass grafting) in 30 patients (33%). Survival at 1 year was 100% and freedom from MACE was 98%. CONCLUSIONS: Patients undergoing CEA have a high prevalence of unsuspected (silent) coronary ischemia, which may place them at risk for coronary events. Preoperative diagnosis of silent ischemia using CTA and FFRCT can identify high-risk patients and help to guide patient management. Selective postoperative coronary revascularization of patients with significant ischemia may decrease the risk of cardiac events and improve survival, but longer follow-up is needed and prospective, controlled trials are indicated.

Pre-operative Diagnosis of Silent Coronary Ischaemia May Reduce Post-operative Death and Myocardial Infarction and Improve Survival of Patients Undergoing Lower Extremity Surgical Revascularisation.

OBJECTIVE: Patients undergoing peripheral vascular surgery have increased risk of death and myocardial infarction (MI), which may be due to unsuspected (silent) coronary ischaemia. The aim was to determine whether pre-operative diagnosis of silent ischaemia using coronary computed tomography (CT) derived fractional flow reserve (FFRCT) can facilitate multidisciplinary care to reduce post-operative death and MI, and improve survival. METHODS: This was a single centre prospective study with historic controls. Patients with no cardiac symptoms undergoing lower extremity surgical revascularisation with pre-operative coronary CTA-FFRCT testing were compared with historic controls with standard pre-operative testing. Silent coronary ischaemia was defined as FFRCT ≤ 0.80 distal to coronary stenosis with FFRCT ≤ 0.75 indicating severe ischaemia. End points included cardiovascular (CV) death, MI, and all cause death through one year follow up. RESULTS: There were no statistically significant differences between CT angiography (CTA-FFRCT) (n = 135) and control (n = 135) patients with regard to age (66 ± 8 years), sex, comorbidities, or surgery performed. Coronary CTA showed ≥ 50% stenosis in 70% of patients with left main stenosis in 7%. FFRCT revealed silent coronary ischaemia in 68% of patients with severe ischaemia in 53%. The status of coronary ischaemia was unknown in the controls. At 30 days, CV death and MI in the CTA-FFRCT group were not statistically significantly different from controls (0% vs. 3.7% [p = .060] and 0.7% vs. 5.2% [p = .066], respectively). Post-operative coronary revascularisation was performed in 54 patients to relieve silent ischaemia (percutaneous coronary intervention in 47, coronary artery bypass graft in seven). At one year, CTA-FFRCT patients had fewer CV deaths (0.7% vs. 5.9%; p = .036) and MIs (2.2% vs. 8.1%; p = .028) and improved survival (p = .018) compared with controls. CONCLUSION: Pre-operative diagnosis of silent coronary ischaemia in patients undergoing lower extremity revascularisation surgery can facilitate multidisciplinary patient care with selective post-operative coronary revascularisation. This strategy reduced post-operative death and MI and improved one year survival compared with standard care.

Initial Clinical Experience Using the Low-Profile Altura Endograft System With Double D-Shaped Proximal Stents for Endovascular Aneurysm Repair.

PURPOSE: To report the initial clinical results of endovascular aneurysm repair (EVAR) using the low-profile (14-F) Altura Endograft System, which features a double "D-shaped" stent design with suprarenal fixation and modular iliac components that are deployed from distal to proximal. METHODS: From 2011 to 2015, 90 patients (mean age 72.8±8.3 years; 79 men) with abdominal aortic aneurysm (AAA; mean diameter 53.8±5.7 mm) were treated at 10 clinical sites in 2 prospective, controlled clinical studies using the Altura endograft. Outcomes evaluated included mortality, major adverse events (MAEs: all-cause death, stroke, paraplegia, myocardial infarction, respiratory failure, bowel ischemia, and blood loss ≥1000 mL), and clinical success (freedom from procedure-related death, type I/III endoleak, migration, thrombosis, and reintervention). RESULTS: Endografts were successfully implanted in 89 (99%) patients; the single failure was due to delivery system malfunction before insertion in the early-generation device. One (1%) patient died and 4 patients underwent reinterventions (1 type I endoleak, 2 iliac limb stenoses, and 1 endograft occlusion) within the first 30 days. During a median follow-up of 12.5 months (range 11.5-50.9), there were no aneurysm ruptures, surgical conversions, or AAA-related deaths. The cumulative MAE rates were 3% (3/89) at 6 months and 7% (6/89) at 1 year. Two patients underwent coil embolization of type II endoleaks at 6.5 months and 2.2 years, respectively. Clinical success was 94% (84/89) at 30 days, 98% (85/87) at 6 months, and 99% (82/83) at 1 year. CONCLUSION: Early results suggest that properly selected AAA patients can be safely treated using the Altura Endograft System with favorable midterm outcome. Thus, further clinical investigation is warranted to evaluate the role of this device in the treatment of AAA.

Automated estimation of image quality for coronary computed tomographic angiography using machine learning.

OBJECTIVES: Our goal was to evaluate the efficacy of a fully automated method for assessing the image quality (IQ) of coronary computed tomography angiography (CCTA). METHODS: The machine learning method was trained using 75 CCTA studies by mapping features (noise, contrast, misregistration scores, and un-interpretability index) to an IQ score based on manual ground truth data. The automated method was validated on a set of 50 CCTA studies and subsequently tested on a new set of 172 CCTA studies against visual IQ scores on a 5-point Likert scale. RESULTS: The area under the curve in the validation set was 0.96. In the 172 CCTA studies, our method yielded a Cohen's kappa statistic for the agreement between automated and visual IQ assessment of 0.67 (p < 0.01). In the group where good to excellent (n = 163), fair (n = 6), and poor visual IQ scores (n = 3) were graded, 155, 5, and 2 of the patients received an automated IQ score > 50 %, respectively. CONCLUSION: Fully automated assessment of the IQ of CCTA data sets by machine learning was reproducible and provided similar results compared with visual analysis within the limits of inter-operator variability. KEY POINTS: • The proposed method enables automated and reproducible image quality assessment. • Machine learning and visual assessments yielded comparable estimates of image quality. • Automated assessment potentially allows for more standardised image quality. • Image quality assessment enables standardization of clinical trial results across different datasets.

Effect of the ratio of coronary arterial lumen volume to left ventricle myocardial mass derived from coronary CT angiography on fractional flow reserve.

BACKGROUND: We hypothesize that in patients with suspected coronary artery disease (CAD), lower values of the ratio of total epicardial coronary arterial lumen volume to left ventricular myocardial mass (V/M) result in lower fractional flow reserve (FFR). METHODS: V/M was computed in 238 patients from the NXT trial who underwent coronary computed tomography angiography (CTA), quantitative coronary angiography (QCA) and FFR measurement in 438 vessels. Nitroglycerin was administered prior to CT, QCA and FFR acquisition. The V/M ratio was quantified on a patient-level from CT image data by segmenting the epicardial coronary arterial lumen volume (V) and the left ventricular myocardial mass (M). Calcified and noncalcified plaque volumes were quantified using semi-automated software. RESULTS: The median value of V/M (18.57 mm3/g) was used to define equal groups of low and high V/M patients. Patients with low V/M had greater diameter stenosis by QCA, more plaque and lower FFR (0.80 ± 0.12 vs. 0.87 ± 0.08; P < 0.0001) than those with high V/M. A total of 365 vessels in 202 patients had QCA stenosis ≤50% and measured FFR. In these patients, those with low V/M had higher percent diameter stenosis by QCA, greater total plaque volume and lower FFR (0.81 ± 0.12 vs. 0.88 ± 0.07; P < 0.0001) than those with high V/M. In multivariate logistic regression analysis, V/M was an independent predictor of FFR ≤0.80 (all p-values < 0.001). CONCLUSIONS: Patients with a low V/M ratio have lower FFR overall and in non-obstructive CAD, independent of plaque measures.

FFR Derived From Coronary CT Angiography in Nonculprit Lesions of Patients With Recent STEMI.

OBJECTIVES: This study sought to determine the diagnostic performance of noninvasive fractional flow reserve (FFR) derived from coronary computed tomography angiography (CTA) (FFRCT) for the diagnosis of lesion-specific ischemia in nonculprit vessels of patients with recent in ST-segment elevation myocardial infarction (STEMI). BACKGROUND: In patients with stable angina, FFRCT has high diagnostic performance in identification of ischemia-causing lesions. The potential value of FFRCT for assessment of multivessel disease in patients with recent STEMI has not been evaluated. METHODS: Coronary CTA with calculation of FFRCT and invasive coronary angiography with FFR were performed 1 month after STEMI in patients with multivessel disease. Coronary CTA and invasive coronary angiography stenosis >50% were considered obstructive. Lesion-specific ischemia was assumed if FFRCT was ≤0.80. FFR ≤0.80 was the reference standard. To evaluate the influence of vessel size, the total coronary vessel lumen volume relative to left ventricular mass (volume-to-mass ratio) was calculated and compared with that of patients with stable angina. RESULTS: The study evaluated 124 nonculprit vessels from 60 patients. Accuracy, sensitivity, and specificity of FFRCT were 72%, 83%, and 66% versus 64% (p = 0.033), 93% (p = 0.15), and 49% (p < 0.001) for CTA and 72% (p = 1.00), 76% (p = 0.46), and 70% (p = 0.54) for invasive coronary angiography. Following STEMI, median volume-to-mass ratio was lower than in patients with stable angina, 53 versus 65 mm3/g (p = 0.009). In patients with volume-to-mass ratio ≥65 mm3/g (upper tertile) accuracy, sensitivity, and specificity of FFRCT were all 83% versus 56% (p = 0.009), 75% (p = 0.61), and 44% (p = 0.003) in patients with <49 mm3/g (lower tertile). CONCLUSIONS: The diagnostic performance of FFRCT for staged detection of ischemia in STEMI patients with multivessel disease is moderate. STEMI patients have a smaller vessel volume than do patients with stable angina. The diagnostic performance of FFRCT is influenced by the volume-to-mass ratio. This study does not support routine use of FFRCT in the post-STEMI setting. (Assessment of Coronary Stenoses Using Coronary CT-Angiography and Noninvasive Fractional Flow Reserve; NCT01739075).