Quantitative Coronary Angiography Stenosis Research Articles

Abstract 15023: Fractional Flow Reserve-Guided Complete Revascularization in AMI Patients With Angiographically Severe Non-Culprit Lesion: FRAME-AMI Substudy

Background: The benefit of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) for non-culprit lesions with angiographically severe stenosis in patients with acute myocardial infarction (AMI) is unclear Objectives We evaluated the relationship between non-culprit lesion stenosis measured by quantitative coronary angiography (QCA) and the efficacy of FFR-guided PCI Methods: Severity of non-culprit lesion stenosis of 562 patients from FRAME-AMI (FFR vs. Angiography-Guided Strategy for Management of Non-Infarction Related Artery Stenosis in Patients with AMI) was measured using QCA in the core laboratory. The effect of FFR-guided versus angiography-guided PCI according to non-culprit lesion stenosis (QCA stenosis ≥70% or <70%) on the primary end point (risk of death, MI or repeat revascularization) was analyzed Results: At a median follow-up of 3.5 years, the primary end point occurred in 14 patients of 181 patients with FFR-guided PCI and 31 of 197 patients with angiography-guided PCI among patient with QCA stenosis ≥70% (7.7% vs 15.7%; hazard ratio, 0.48; 95% confidence interval, 0.25 to 0.90; P=0.022), while occurred in 4 of 103 patients with FFR-guided PCI and 9 of 81 patients with angiography-guided PCI among those with QCA stenosis < 70% (3.9% vs 11.1%, p=0.079). FFR-guided PCI was associated with the reduction of death and myocardial infarction in patients with QCA stenosis ≥70% (6.1% vs 13.7%, p=0.019) and those with QCA stenosis < 70% (1.0% vs 9.9%, p=0.028) compare to angiography-guided PCI Conclusions: In patients with AMI and multivessel disease, patients with severe non-infarct related artery lesion was also benefited by FFR-guided PCI.

Angiographic Severity of the Nonculprit Lesion and the Efficacy of Fractional Flow Reserve-Guided Complete Revascularization in Patients With AMI: FRAME-AMI Substudy.

The benefit of fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) for noninfarct-related artery (IRA) lesions with angiographically severe stenosis in patients with acute myocardial infarction is unclear. Among 562 patients from the FRAME-AMI trial (Fractional Flow Reserve Versus Angiography-Guided Strategy for Management of Non-Infraction Related Artery Stenosis in Patients With Acute Myocardial Infarction) who were randomly allocated into either FFR-guided or angiography-guided PCI for non-IRA lesions, the current study evaluated the relationship between non-IRA stenosis measured by quantitative coronary angiography (QCA) and the efficacy of FFR-guided PCI. The incidence of the primary end point (death, myocardial infarction, or repeat revascularization) was compared between FFR- and angiography-guided PCI according to non-IRA stenosis severity (QCA stenosis ≥70% or <70%). A total of 562 patients were assigned to FFR-guided (n=284) versus angiography-guided PCI (n=278). At a median follow-up of 3.5 years, the primary end point occurred in 14 of 181 patients with FFR-guided PCI and 31 of 197 patients with angiography-guided PCI among patients with QCA stenosis ≥70% (8.5% versus 19.2%; hazard ratio, 0.41 [95% CI, 0.22-0.80]; P=0.008), while occurred in 4 of 103 patients with FFR-guided PCI and 9 of 81 patients with angiography-guided PCI among those with QCA stenosis <70% (3.9% versus 11.1%; P=0.315). There was no significant interaction between treatment strategy and non-IRA stenosis severity (P for interaction=0.636). FFR-guided PCI was associated with the reduction of death and myocardial infarction in both patients with QCA stenosis ≥70% (6.7% versus 15.1%; P=0.008) and those with QCA stenosis <70% (1.0% versus 9.6%; P=0.042) compared with angiography-guided PCI. In patients with acute myocardial infarction and multivessel disease, FFR-guided PCI tended to have a lower risk of primary end point than angiography-guided PCI regardless of non-IRA stenosis severity without significant interaction. URL: https://www.clinicaltrials.gov; Unique identifier: NCT02715518.

Stress Perfusion Cardiac Magnetic Resonance vs SPECT Imaging for Detection of Coronary Artery Disease

BackgroundGadaCAD2 was 1 of 2 international, multicenter, prospective, Phase 3 clinical trials that led to U.S. Food and Drug Administration approval of gadobutrol to assess myocardial perfusion and late gadolinium enhancement (LGE) in adults with known or suspected coronary artery disease (CAD). ObjectivesA prespecified secondary objective was to determine if stress perfusion cardiovascular magnetic resonance (CMR) was noninferior to single-photon emission computed tomography (SPECT) for detecting significant CAD and for excluding significant CAD. MethodsParticipants with known or suspected CAD underwent a research rest and stress perfusion CMR that was compared with a gated SPECT performed using standard clinical protocols. For CMR, adenosine or regadenoson served as vasodilators. The total dose of gadobutrol was 0.1 mmol/kg body weight. The standard of reference was a 70% stenosis defined by quantitative coronary angiography (QCA). A negative coronary computed tomography angiography could exclude CAD. Analysis was per patient. CMR, SPECT, and QCA were evaluated by independent central core lab readers blinded to clinical information. ResultsParticipants were predominantly male (61.4% male; mean age 58.9 ± 10.2 years) and were recruited from the United States (75.0%), Australia (14.7%), Singapore (5.7%), and Canada (4.6%). The prevalence of significant CAD was 24.5% (n = 72 of 294). Stress perfusion CMR was statistically superior to gated SPECT for specificity (P = 0.002), area under the receiver operating characteristic curve (P < 0.001), accuracy (P = 0.003), positive predictive value (P < 0.001), and negative predictive value (P = 0.041). The sensitivity of CMR for a 70% QCA stenosis was noninferior and nonsuperior to gated SPECT. ConclusionsVasodilator stress perfusion CMR, as performed with gadobutrol 0.1 mmol/kg body weight, had superior diagnostic accuracy for diagnosis and exclusion of significant CAD vs gated SPECT.

Novel application of intravascular lithotripsy in stent under-expansion: A single-center experience.

Stent under-expansion due to calcification is associated with a less durable result. The development of intravascular lithotripsy (IVL) has provided clinicians with a readily available, simple-to-use treatment option for coronary calcification, but the use of IVL within a previously stented segment is currently off-license. There are, however, developing data suggesting that the use of IVL can be an effective treatment option for patients with calcific stent under-expansion. This was a single-center study of all patients treated with IVL for calcific stent under-expansion between January 2019 and June 2021. The impact of IVL on quantitative coronary angiography (QCA) stenosis and on the minimal stent area (MSA) derived from intracoronary imaging were recorded. The presence of periprocedural complications and adverse cardiovascular events was obtained from the clinical record during the study timeframe. Thirty-nine patients underwent IVL for calcific stent under-expansion during the study time frame with one patient treated with more than one lesion in the same session. In all lesions, there was an improvement in the QCA stenosis with 37 (92.5%) having a residual stenosis of ≤30%. The mean QCA stenosis pre-IVL was 68 ± 21% and following IVL the mean QCA was 18 ± 9% (p < 0.001). In all lesions, there was an improvement in the MSA, with 26 (92.9%) achieving an MSA of more than 4.5 mm2. The mean MSA pre-IVL was 3.88 ± 1.51 mm2 and following IVL the mean MSA was 7.41 ± 2.34 mm2 (p < 0.001). There were no major procedural complications. Over a mean follow-up of 506 ± 277 days, one patient died from ventricular arrhythmia but there were no other major adverse cardiovascular events. This single-center study demonstrates that IVL is a safe and effective treatment for calcific stent under-expansion with good medium-term results.

Coronary CTA plaque volume severity stages according to invasive coronary angiography and FFR

BackgroundAtherosclerotic plaque characterization by coronary computed tomography angiography (CCTA) enables quantification of coronary artery disease (CAD) burden and type, which has been demonstrated as the strongest discriminant of future risk of major adverse cardiac events (MACE). To date, there are no clinically useful thresholds to assist with understanding a patient's disease burden and guide diagnosis and management, as there exists with coronary artery calcium (CAC) scoring. The purpose of this manuscript is to establish clinically relevant plaque stages and thresholds based on evidence from invasive angiographic stenosis (ICA) and fractional flow reserve (FFR) data. Methods303 patients underwent CCTA prior to ICA and FFR for an AHA/ACC clinical indication. Quantitative computed tomography (QCT) was performed for total plaque volume (TPV, mm3) and percent atheroma volume (PAV, %). We segmented atherosclerosis by composition for low-density non-calcified plaque (LD-NCP), non-calcified plaque (NCP), and calcified plaque (CP). ICAs were evaluated by quantitative coronary angiography (QCA) for all coronary segments for % diameter stenosis. The relationship of atherosclerotic plaque burden and composition by QCT to ICA stenosis extent and severity by QCA and presence of ischemia by FFR was assessed to develop 4 distinct disease stages. ResultsThe mean age of the patients was 64.4 ​± ​10.2 years; 71% male. At the 50% QCA stenosis threshold, QCT revealed a mean PAV of 9.7 (±8.2)% and TPV of 436 (±444.9)mm3 for those with non-obstructive CAD; PAV of 11.7 (±8.0)% and TPV of 549.3 (±408.3) mm3 for 1 vessel disease (1VD), PAV of 17.8 (±9.8)% and TPV of 838.9 (±550.7) mm3 for 2VD, and PAV of 19.2 (±8.2)% and TPV of 799.9 (±357.4) mm3 for 3VD/left main disease (LMD). Non-ischemic patients (FFR >0.8) had a mean PAV of 9.2 (±7.3) % and TPV of 422.9 (±387.9 ​mm3) while patients with at least one vessel ischemia (FFR ≤0.8) had a PAV of 15.2 (±9.5)% and TPV of 694.6 (±485.1). Definition of plaque stage thresholds of 0, 250, 750 ​mm3 and 0, 5, and 15% PAV resulted in 4 clinically distinct stages in which patients with no, nonobstructive, single VD and multi-vessel disease were optimally distributed. ConclusionAtherosclerotic plaque burden by QCT is related to stenosis severity and extent as well as ischemia. We propose staging of CAD atherosclerotic plaque burden using the following definitions: Stage 0 (Normal, 0% PAV, 0 ​mm3 TPV), Stage 1 (Mild, >0–5% PAV or >0–250 ​mm3 TPV), Stage 2 (Moderate, >5–15% PAV or >250–750 ​mm3 TPV) and Stage 3 (Severe, >15% PAV or >750 mm3 TPV).

Nonculprit Lesion Severity and Outcome of Revascularization in Patients With STEMI and Multivessel Coronary Disease

BackgroundIn the COMPLETE (Complete vs Culprit-only Revascularization to Treat Multi-vessel Disease After Early PCI for STEMI) trial, angiography-guided percutaneous coronary intervention (PCI) of nonculprit lesions with the aim of complete revascularization reduced major cardiovascular (CV) events in patients with ST-segment elevation myocardial infarction (MI) and multivessel coronary artery disease. ObjectivesThe purpose of this study was to determine the effect of nonculprit-lesion stenosis severity measured by quantitative coronary angiography (QCA) on the benefit of complete revascularization. MethodsAmong 4,041 patients randomized in the COMPLETE trial, nonculprit lesion stenosis severity was measured using QCA in the angiographic core laboratory in 3,851 patients with 5,355 nonculprit lesions. In pre-specified analyses, the treatment effect in patients with QCA stenosis ≥60% versus <60% on the first coprimary outcome of CV death or new MI and the second co-primary outcome of CV death, new MI, or ischemia-driven revascularization was determined. ResultsThe first coprimary outcome was reduced with complete revascularization in the 2,479 patients with QCA stenosis ≥60% (2.5%/year vs. 4.2%/year; hazard ratio [HR]: 0.61; 95% confidence interval [CI]: 0.47 to 0.79), but not in the 1,372 patients with QCA stenosis <60% (3.0%/year vs. 2.9%/year; HR: 1.04; 95% CI: 0.72 to 1.50; interaction p = 0.02). The second coprimary outcome was reduced in patients with QCA stenosis ≥60% (2.9%/year vs. 6.9%/year; HR: 0.43; 95% CI: 0.34 to 0.54) to a greater extent than patients with QCA stenosis <60% (3.3%/year vs. 5.2%/year; HR: 0.65; 95% CI: 0.47 to 0.89; interaction p = 0.04). ConclusionsAmong patients with ST-segment elevation MI and multivessel coronary artery disease, complete revascularization reduced major CV outcomes to a greater extent in patients with stenosis severity of ≥60% compared with <60%, as determined by quantitative coronary angiography.

Gadobutrol-Enhanced Cardiac Magnetic Resonance Imaging for Detection of Coronary Artery Disease

BackgroundGadolinium-based contrast agents were not approved in the United States for detecting coronary artery disease (CAD) prior to the current studies. ObjectivesThe purpose of this study was to determine the sensitivity and specificity of gadobutrol for detection of CAD by assessing myocardial perfusion and late gadolinium enhancement (LGE) imaging. MethodsTwo international, single-vendor, phase 3 clinical trials of near identical design, “GadaCAD1” and “GadaCAD2,” were performed. Cardiovascular magnetic resonance (CMR) included gadobutrol-enhanced first-pass vasodilator stress and rest perfusion followed by LGE imaging. CAD was defined by quantitative coronary angiography (QCA) but computed tomography coronary angiography could exclude significant CAD. ResultsBecause the design and results for GadaCAD1 (n = 376) and GadaCAD2 (n = 388) were very similar, results were summarized as a fixed-effect meta-analysis (n = 764). The prevalence of CAD was 27.8% defined by a ≥70% QCA stenosis. For detection of a ≥70% QCA stenosis, the sensitivity of CMR was 78.9%, specificity was 86.8%, and area under the curve was 0.871. The sensitivity and specificity for multivessel CAD was 87.4% and 73.0%. For detection of a 50% QCA stenosis, sensitivity was 64.6% and specificity was 86.6%. The optimal threshold for detecting CAD was a ≥67% QCA stenosis in GadaCAD1 and ≥63% QCA stenosis in GadaCAD2. ConclusionsVasodilator stress and rest myocardial perfusion CMR and LGE imaging had high diagnostic accuracy for CAD in 2 phase 3 clinical trials. These findings supported the U.S. Food and Drug Administration approval of gadobutrol-enhanced CMR (0.1 mmol/kg) to assess myocardial perfusion and LGE in adult patients with known or suspected CAD.

Diagnostic performance of virtual fractional flow reserve derived from routine coronary angiography using segmentation free reduced order (1-dimensional) flow modelling

Fractional flow reserve (FFR) improves assessment of the physiological significance of coronary lesions compared with conventional angiography. However, it is an invasive investigation. We tested the performance of a virtual FFR (1D-vFFR) using routine angiographic images and a rapidly performed reduced order computational model. Quantitative coronary angiography (QCA) was performed in 102 with coronary lesions assessed by invasive FFR. A 1D-vFFR for each lesion was created using reduced order (one-dimensional) computational flow modelling derived from conventional angiographic images and patient specific estimates of coronary flow. The diagnostic accuracy of 1D-vFFR and QCA derived stenosis was compared against the gold standard of invasive FFR using area under the receiver operator characteristic curve (AUC). QCA revealed the mean coronary stenosis diameter was 44% ± 12% and lesion length 13 ± 7 mm. Following angiography calculation of the 1DvFFR took less than one minute. Coronary stenosis (QCA) had a significant but weak correlation with FFR (r = -0.2, p = 0.04) and poor diagnostic performance to identify lesions with FFR <0.80 (AUC 0.39, p = 0.09), (sensitivity - 58% and specificity - 26% at a QCA stenosis of 50%). In contrast, 1D-vFFR had a better correlation with FFR (r = 0.32, p = 0.01) and significantly better diagnostic performance (AUC 0.67, p = 0.007), (sensitivity - 92% and specificity - 29% at a 1D-vFFR of 0.7). 1D-vFFR improves the determination of functionally significant coronary lesions compared with conventional angiography without requiring a pressure-wire or hyperaemia induction. It is fast enough to influence immediate clinical decision-making but requires further clinical evaluation.

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

BackgroundWe 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). MethodsV/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. ResultsThe 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). ConclusionsPatients with a low V/M ratio have lower FFR overall and in non-obstructive CAD, independent of plaque measures.

Diagnostic Accuracy of Noninvasive 64-row Computed Tomographic Coronary Angiography (CCTA) Compared with Myocardial Perfusion Imaging (MPI): The PICTURE Study, A Prospective Multicenter Trial

Although multiple studies have shown excellent accuracy statistics for noninvasive angiography by coronary computed tomographic angiography (CCTA), most studies comparing nuclear imaging to CCTA were performed on patients already referred for cardiac catheterization, introducing referral and selection bias. This prospective trial evaluated the diagnostic accuracy of 64-row CCTA to detect obstructive coronary stenosis compared to myocardial perfusion imaging (MPI), using quantitative coronary angiography (QCA) as a reference standard. Twelve sites prospectively enrolled 230 patients (49% male, 57.8 years) with chest pain. All patients underwent MPI and CCTA (Lightspeed VCT/Visipaque 320, GE Healthcare, Milwaukee, WI, USA) prior to invasive coronary angiography (ICA). All patients were evaluated, and those found to have either an abnormal MPI or CCTA were clinically referred for ICA. CCTAs were graded on a 15-segment American Heart Association model by three blinded readers for presence of obstructive stenosis (>50% or >70%); MPI was graded by two blinded readers using a 17-segment model for estimation of the % myocardium ischemic or with stress defects. ICAs were independently graded for % stenosis by QCA. The efficacies of MPI and CCTA were assessed including all vessel segments for per-patient and per-vessel analyses. The prevalence of stenosis ≥50% by ICA was 52.1% (25 of 48). The sensitivity of CCTA was significantly higher than nuclear imaging (92.0% vs 54.5%, P < 0.001), with similar specificity (87.0% vs 78.3%) when obstructive disease was defined as ≥50%. CCTA provided superior sensitivity (92.6% vs 59.3%, P < 0.001) and similar specificity (88.9% vs 81.5%) using QCA stenosis ≥70%. For ≥50% stenosis, the computed tomographic angiography odds ratio for ICA disease was 51.75 (95% CI = 8.50-314.94, P < 0.001). For summed stress score ≥5%, the odds ratio for ICA CAD was 12.73 (95% CI = 2.43-66.55, P < 0.001). Using receiver operating characteristic curve analysis, CCTA was better at classifying obstructive coronary artery disease when compared to MPI (area = 0.85 vs 0.71, P < 0.0001). This study represents one of the first prospective multicenter, controlled clinical trials comparing 64-row CCTA to MPI in the same patients, demonstrating superior diagnostic accuracy of CCTA over myocardial perfusion single photon emission computed tomography (MPS) to reliably detect >50% and >70% stenosis in stable chest pain patients.

Coronary angiographic characteristics that influence fractional flow reserve.

Percutaneous coronary intervention (PCI) guided with fractional flow reserve (FFR) has been shown to improve clinical outcome. Although coronary angiography is the standard method for PCI guidance, the visual severity of stenosis is not always correlated with functional severity, suggesting that there are additional angiographic factors that affect functional ischemia. To evaluate angiographic predictors of positive FFR in stenotic lesions, angiographic characteristics of 260 consecutive patients (362 lesions) who underwent FFR testing from April 2009 to September 2012 were analyzed. A scoring system (STABLED score) using these predictors was developed and compared with quantitative coronary angiography (QCA). %Diameter stenosis >50% (OR, 8.43; P<0.0001), tandem lesion (OR, 4.00; P<0.0001), true bifurcation (OR, 2.42; P=0.028), lesion length >20 mm (OR, 5.40; P=0.0002), and distance from ostium <20 mm (OR, 1.94; P=0.028) were determined as independent predictors of positive FFR. Area under the ROC curve for probability of positive FFR using the STABLED score (Stenosis 2 points, TAndem lesion 1 point, Bifurcation 1 point, LEsion length 1 point, Distance from ostium 1 point) was 0.85, higher than that for QCA stenosis alone (0.76). STABLED score ≥3 had 72.3% sensitivity and 83.6% specificity for predicting positive FFR, and PPV was 76.7%. Specific angiographic features are applicable for predicting functional ischemia. STABLED score correlates well with FFR.