Quantitative flow ratio to predict long-term coronary artery bypass graft patency in patients with left main coronary artery disease.

PURPOSE: Fractional flow reserve (FFR) has been demonstrated in some studies to predict long-term coronary artery bypass graft (CABG) patency. Quantitative flow ratio (QFR) is an emerging technology which may predict FFR. In this study, we hypothesised that QFR would predict long-term CABG patency and that QFR would offer superior diagnostic performance to quantitative coronary angiography (QCA) and intravascular ultrasound (IVUS). METHODS: A prospective study was performed on patients with left main coronary artery disease who were undergoing CABG. QFR, QCA and IVUS assessment was performed. Follow-up computed tomography coronary angiography and invasive coronary angiography was undertaken to assess graft patency. RESULTS: A total of 22 patients, comprising of 65 vessels were included in the analysis. At a median follow-up of 3.6 years post CABG (interquartile range, 2.3 to 4.8 years), 12 grafts (18.4%) were occluded. QFR was not statistically significantly higher in occluded grafts (0.81 ± 0.19 vs. 0.69 ± 0.21; P = 0.08). QFR demonstrated a discriminatory power to predict graft occlusion (area under the receiver operating characteristic curve, 0.70; 95% confidence interval [CI], 0.52 to 0.88; P = 0.03). At long-term follow-up, the risk of graft occlusion was higher in vessels with a QFR > 0.80 (58.6% vs. 17.0%; hazard ratio, 3.89; 95% CI, 1.05 to 14.42; P = 0.03 by log-rank test). QCA (minimum lumen diameter, lesion length, diameter stenosis) and IVUS (minimum lumen area, minimum lumen diameter, diameter stenosis) parameters were not predictive of long-term graft patency. CONCLUSIONS: QFR may predict long-term graft patency in patients undergoing CABG.

The role of intravascular ultrasound in percutaneous coronary intervention of complex coronary lesions.

Intravascular ultrasound (IVUS) is a catheter-based coronary imaging technique. It utilises the emission & subsequent detection of reflected high frequency (30-60 MHz) sound waves to create high resolution, cross-sectional images of the coronary artery. IVUS has been the cornerstone of intracoronary imaging for more than two decades. When compared to the invasive coronary angiogram which studies only the silhouette of the contrast-filled artery lumen, IVUS also crucially images the vessel wall. Because of this capability, IVUS has greatly facilitated understanding of the coronary atherosclerosis process. Such insights from IVUS reveal how commonly and extensively plain angiography underestimates the true extent of coronary plaque, the characteristics of plaques prone to rupture and cause acute coronary syndromes (lipid rich, thin cap atheroma), and a realisation of the widespread occurrence of vessel remodelling in response to atherosclerosis. Similarly, IVUS has historically provided salutary mechanistic insights that have guided many of the incremental advances in the techniques of percutaneous coronary intervention (PCI). Examples include mechanisms of in-stent restenosis, and the importance of high-pressure post-dilatation of stents to ensure adequate stent apposition and thereby reduce the occurrence of stent thrombosis. IVUS also greatly facilitates the choice of correct diameter and length of stent to implant. Overall, a compelling body of evidence indicates that use of intravascular ultrasound in PCI helps to achieve optimal technical results and to mitigate the risk of adverse cardiac events. In this review, the role of intravascular ultrasound as an adjunct to PCI in complex coronary lesions is explored. The complex coronary situations discussed are the left main stem, ostial stenoses, bifurcation stenoses, thrombotic lesions, the chronically occluded coronary artery, and calcified coronary artery disease. By thorough review of the available evidence, we establish that the advantages of IVUS guidance are particularly evident in each of these complex CAD subsets. In particular, some consider the use of IVUS to be almost mandatory in left main PCI. A comparison with other intracoronary imaging techniques is also explored.

Procedural and Clinical Outcomes in Management of Bifurcational Lesions in ST Elevation Myocardial Infarction.

BACKGROUND: Bifurcation percutaneous coronary intervention (PCI) remains a challenging frontier in interventional cardiology, especially in the setting of ST-elevation myocardial infarction (STEMI). We examined the procedural and clinical outcomes of this patient subset. METHODS: We conducted a retrospective case-control study. Between February 2006 and March 2011, 129 patients with STEMI underwent bifurcation PCI at our institution. One hundred and twenty-nine (129) control STEMI patients with non-bifurcation PCI were selected from the institutional database, matched for age, gender, culprit vessel, and lesion location. Patients with cardiac arrest, cardiogenic shock, or who required mechanical ventilation were excluded. Twelve (12)-month follow-up data were collected by telephone calls and examination of the medical records. RESULTS: The average age of patients presenting with STEMI was 61.6 ± 13.1 in the bifurcation group and 61.5 + 31.1 in the non-bifurcation group. There was no difference in lesion type, use of thrombus aspiration catheters, or glycoprotein inhibitors (GPI) among them. Also, the use of drug eluting stent (DES), total cumulative length of stent used, and diameter of the post-dilation balloon were similar. Final kissing balloon post-dilation was performed in 40.3% of bifurcation PCI cases. The incidence of procedural failure (TIMI 0 flow) was 1.5% vs. 0%; p = 0.478. At 12-months follow-up, the bifurcation PCI group had higher incidence of target lesion revascularisation (TLR) (10.9% vs. 3.9%, p = 0.050), mortality (10.1% vs. 2.3%, p = 0.020), and stent thrombosis (9.3% vs. 1.6%; p = 0.013); comprising one acute, nine subacute, and two late vs. two subacute stent thromboses. CONCLUSIONS: During acute STEMI, bifurcation PCI has excellent acute procedural outcomes, but significantly increased incidence of TLR, stent thrombosis and mortality at 12 months.

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.

Bleeding outcomes after non-emergency percutaneous coronary intervention in the very elderly.

BACKGROUND: Octogenarians constitute an increasing proportion of patients presenting for non-emergency percutaneous coronary intervention (PCI). METHODS: This study evaluated the in-hospital procedural characteristics and outcomes, including the bleeding events of 293 octogenarians presenting between January 2010 and December 2012 for non-emergency PCI to a single large volume tertiary care Australian center. Comparisons were made with 293 consecutive patients aged less than or equal to 60 years, whose lesions were matched with the octogenarians. RESULTS: Non-ST elevation myocardial infarction was the most frequent indication for non-emergency PCI in octogenarians. Compared to the younger cohort, they had a higher prevalence of co-morbidities and more complex coronary disease, comprising more type C and calcified lesions. Peri-procedural use of low molecular weight heparin (LMWH; 1.0% vs. 5.8%; P < 0.001) and glycoprotein IIb/IIIa inhibitors (2.1% vs. 9.6%; P < 0.001) was lower, while femoral arterial access was used more commonly than in younger patients (80.9% vs. 67.6%; P < 0.001). Overall, there was a non-significant trend towards higher incidence of all bleeding events in the elderly (9.2% vs. 5.8%; P = 0.12). There was no significant difference in access site or non-access site bleeding and major or minor bleeding between the two cohorts. Sub-analysis did not reveal any significant influence on bleeding rates by the use of LMWH, glycoprotein IIb/IIIa inhibitors or femoral arterial access. In addition, there were no significant differences in the rates of in-hospital mortality, stroke or acute stent thrombosis between the two groups. CONCLUSIONS: In this single center study, we did not observe significant increases in adverse in-hospital outcomes including the incidence of bleeding in octogenarians undergoing non-emergency PCI.

Stenotic flow reserve derived from quantitative coronary angiography has modest but incremental value in predicting functionally significant coronary stenosis as evaluated by fractional flow reserve.

BACKGROUND: Stenotic flow reserve (SFR) derived from quantitative coronary angiography (QCA) has been correlated with myocardial ischaemia as determined by pharmacological stress echocardiography. However, the diagnostic accuracy of SFR in predicting functionally significant coronary stenosis as assessed by the gold standard, fractional flow reserve (FFR), has not been previously characterised. METHODS: Patients who underwent coronary angiography and FFR assessment between January 2010 and February 2012 in a single tertiary centre were retrospectively assessed. QCA parameters such as minimal lumen diameter (MLD), lesion length, diameter stenosis (DS), SFR, turbulent resistance (TR) and Poiseuille resistance (PR) were assessed. Significant FFR was defined as FFR ≤0.8. The diagnostic accuracy of QCA parameters to predict significant FFR was assessed by independent t-test and receiver operator characteristic (ROC) curve. Statistical significance was defined as P value of <0.05. RESULTS: The study included 272 patients (age: 64±11, 70% males) and 415 vessels. There were 180 (43%) vessels which were FFR significant. The mean FFR value for all vessels was 0.81±0.11. On comparison of AUC for predicting significant FFR, SFR (AUC =0.76) had the highest diagnostic accuracy compared to PR (AUC =0.75), % DS (AUC =0.73), TR (AUC =0.69), MLD (AUC =0.71) and DS >50% (AUC =0.64). Using a retrospectively determined optimal cut-off value of 3.51, the sensitivity of stenotic-flow-reserve was modest at 56% with good specificity of 81%. DS >50% had a sensitivity of 47% and specificity of 82% in predicting significant FFR. There was incremental predictive value when SFR was added to DS >50% on integrated discrimination improvement index (IDI =0.103, P<0.001) and net reclassification index (NRI =0.72, P<0.001). CONCLUSIONS: SFR has modest diagnostic accuracy for predicting significant FFR but adds incremental predictive value to DS >50% for predicting significant FFR.

Outcomes After Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction Caused by Ectatic Infarct Related Arteries.

BACKGROUND: There is minimal published data on outcomes of patients presenting with ST elevation myocardial infarction (STEMI) due to an ectatic infarct-related artery (EIRA). The aim of this study was to analyse the clinical characteristics and outcomes of these patients presenting for primary percutaneous coronary intervention (P-PCI) in comparison with non-EIRA. METHODS: Of the 1834 patients who presented at our institution for P-PCI between February 2008 and November 2013, 25 (1.4%) were identified as having an EIRA. These patients were compared with those with non-EIRA (80 patients) who were age, gender and lesion matched. Further sub-group analysis on in-hospital and long-term outcomes was done comparing EIRA stented and non-stented patients. Clinical events evaluated include death, recurrent infarction, unstable angina, or target lesion revascularisation (TLR). RESULTS: Baseline characteristics were similar between patients with EIRA and non-EIRA although none of those with EIRA had diabetes mellitus. By comparison to the non-EIRA group, the major procedural differences for patients with EIRA were (1) a greater incidence of large thrombus burden (96.0% vs 22.5%, p=0.0001), (2) increased usage of peri-procedural glycoprotein IIb/IIIa inhibitors (72.0% vs 37.5%, p=0.01) and post-procedural anticoagulation (28.0% vs 5.0%, p=0.004), (3) larger mean stent dimension (3.9±0.8mm vs 3.4±0.6mm, p=0.04) and (4) a higher percentage of P-PCI cases that did not have stent deployment (44.0% vs 7.5%, p=0.0001). Patients with STEMI from EIRA had similar in-hospital outcomes but a higher long-term incidence of composite cardiovascular events at mean follow-up of 36.6±14.1months (44.0% vs 16.3% for non-EIRA, p=0.01). Although patients with EIRA who received stenting had better in-hospital outcomes than the non-stented cohort (composite cardiovascular event rate: 0.0% vs 36.4%, p=0.03), long-term outcomes were comparable (35.7% vs 54.6%, p=0.59) due to a relatively high frequency of non-fatal MI and unstable angina in both groups. CONCLUSION: Patients with STEMI due to EIRA carry worse long-term outcomes than those with non-EIRA. While successful stent deployment in the setting of EIRA improves procedural and inpatient success rates, it does not necessarily convey benefit to long-term event rates due to recurrent acute coronary syndromes.

Noninvasive CT-Derived FFR Based on Structural and Fluid Analysis: A Comparison With Invasive FFR for Detection of Functionally Significant Stenosis.

OBJECTIVES: This study describes the feasibility and accuracy of a novel computed tomography (CT) fractional flow reserve (FFR) technique based on alternative boundary conditions. BACKGROUND: Techniques used to compute FFR based on images acquired from coronary computed tomography angiography (CTA) are described. Boundary conditions were typically determined by allometric scaling laws and assumptions regarding microvascular resistance. Alternatively, boundary conditions can be derived from the structural deformation of coronary lumen and aorta, although its accuracy remains unknown. METHODS: Forty-two patients (78 vessels) in a single institution prospectively underwent 320-detector coronary CTA and FFR. Deformation of coronary cross-sectional lumen and aorta, computed from coronary CTA images acquired over diastole, was used to determine the boundary conditions based on hierarchical Bayes modeling. CT-FFR was derived using a reduced order model performed using a standard desktop computer and dedicated software. First, 12 patients (20 vessels) formed the derivation cohort to determine optimal CT-FFR threshold with which to detect functional stenosis, defined as FFR of ≤0.8, which was validated in the subsequent 30 patients (58 vessels). RESULTS: Derivation cohort results demonstrated optimal threshold for CT-FFR was 0.8 with 67% sensitivity and 91% specificity. In the validation cohort, CT-FFR was successfully computed in 56 of 58 vessels (97%). Compared with coronary CTA, CT-FFR at ≤0.8 demonstrated a higher specificity (87% vs. 74%, respectively) and positive predictive value (74% vs. 60%, respectively), with comparable sensitivity (78% vs. 79%, respectively), negative predictive value (89% vs. 88%, respectively), and accuracy (area under the curve: 0.88 vs. 0.77, respectively; p = 0.22). Based on Bland-Altman analysis, mean intraobserver and interobserver variability values for CT-FFR were, respectively, -0.02 ± 0.05 (95% limits of agreement: -0.12 to 0.08) and 0.03 ± 0.06 (95% limits: 0.07 to 0.19). Mean time per patient for CT-FFR analysis was 27.07 ± 7.54 min. CONCLUSIONS: CT-FFR based on alternative boundary conditions and reduced-order fluid model is feasible, highly reproducible, and may be accurate in detecting FFR ≤ 0.8. It requires a short processing time and can be completed at point-of-care. Further validation is required in large prospective multicenter settings.

Intravascular ultrasound guidance improves clinical outcomes during implantation of both first- and second-generation drug-eluting stents: a meta-analysis.

AIMS: Our aim was to assess whether intravascular ultrasound (IVUS) improves clinical outcomes during implantation of first- and second-generation drug-eluting stents (DES). IVUS guidance is associated with improved clinical outcomes during DES implantation, but it is unknown whether this benefit is limited to either first- or second-generation devices. METHODS AND RESULTS: MEDLINE, EMBASE and PubMed were searched for studies comparing outcomes between IVUS- and angiography-guided PCI. Among 909 potentially relevant studies, 15 trials met the inclusion criteria. The primary endpoint was MACE, defined as death, myocardial infarction, target vessel/lesion revascularisation (TVR/TLR) or stent thrombosis (ST). Summary estimates were obtained using Peto modelling. In total, 9,313 patients from six randomised trials and nine observational studies were included. First-generation DES were implanted in 6,156 patients (3,064 IVUS-guided and 3,092 angiography-guided) and second-generation in 3,157 patients (1,528 IVUS-guided and 1,629 angiography-guided). IVUS guidance was associated with a significant reduction in MACE (odds ratio [OR] 0.73, 95% CI: 0.64-0.85, p<0.001), across both first- (OR 0.79, 95% CI: 0.67-0.92, p=0.01) and second-generation DES (0.57, 95% CI: 0.43-0.77, p<0.001). For second-generation DES, IVUS guidance was associated with significantly lower rates of cardiac death (OR 0.33, 95% CI: 0.14-0.78, p=0.02), TVR (OR 0.47, 95% CI: 0.28-0.79, p=0.006), TLR (OR 0.61, 95% CI: 0.42-0.90, p=0.01) and ST (OR 0.31, 95% CI: 0.12-0.78, p=0.02). Cumulative meta-analysis highlighted progressive temporal benefit towards IVUS-guided PCI to reduce MACE (OR 0.60, 95% CI: 0.48-0.75, p<0.001). CONCLUSIONS: IVUS guidance is associated with a significant reduction in MACE during implantation of both first- and second-generation DES platforms. These data support the use of IVUS guidance in contemporary revascularisation procedures using second-generation DES.

Chronic Total Occlusion - Percutaneous Coronary Intervention (CTO-PCI) Experience in a Single, Multi-operator Australian Centre: Need for dedicated CTO-PCI programs.

BACKGROUND: Chronic total occlusions (CTOs) represent a unique set of lesions for percutaneous coronary intervention (PCI) because of the complexity of techniques required to treat them. METHODS: We retrospectively reviewed the CTO-PCI experience between January 2010 and December 2012, in a multi-operator single centre, which is one of the largest volume PCI centres in Australia. RESULTS: Eighty-two patients (62.6±11.3 years, 85% males) who had CTO-PCIs were included. The most common site of CTO was the right coronary artery (44%), followed by the left circumflex (30%) and left anterior descending (26%) arteries. Using the Japanese CTO scoring system, 34% of lesions were classified as easy, 37% intermediate, 23% difficult and 6% very difficult. All PCIs were performed by antegrade approach. Selected procedural characteristics included: re-attempt procedure 10%; multiple access sites 21%; more than one guidewire 77%; additional support modality 60%; drug-eluting stents 97%; stent number 1.6±0.8; total stent length 40.1±24.5mm; fluoroscopy time 33±17min; contrast volume 257.2±110.8mL. Overall CTO success rate was 60%. In-hospital adverse outcomes included 1.2% mortality, 9.8% peri-procedural myocardial infarction, 4.9% emergency bypass surgery, 3% cardiac tamponade and 4.9% contrast induced nephropathy. CONCLUSION: We report modest success rates in a single Australian centre experience in a relatively conservative cohort of CTO-PCI prior to the initiation of a dedicated CTO revascularisation program.

An overview of PCI in the very elderly.

Cardiovascular disease, and in particular ischemic heart disease (IHD), is a major cause of morbidity and mortality in the very elderly (> 80 years) worldwide. These patients represent a rapidly growing cohort presenting for percutaneous coronary intervention (PCI), now constituting more than one in five patients treated with PCI in real-world practice. Furthermore, they often have greater ischemic burden than their younger counterparts, suggesting that they have greater scope of benefit from coronary revascularization therapy. Despite this, the very elderly are frequently under-represented in clinical revascularization trials and historically there has been a degree of physician reluctance in referring them for PCI procedures, with perceptions of disappointing outcomes, low success and high complication rates. Several issues have contributed to this, including the tendency for older patients with IHD to present late, with atypical symptoms or non-diagnostic ECGs, and reservations regarding their procedural risk-to-benefit ratio, due to shorter life expectancy, presence of comorbidities and increased bleeding risk from antiplatelet and anticoagulation medications. However, advances in PCI technology and techniques over the past decade have led to better outcomes and lower risk of complications and the existing body of evidence now indicates that the very elderly actually derive more relative benefit from PCI than younger populations. Importantly, this applies to all PCI settings: elective, urgent and emergency. This review discusses the role of PCI in the very elderly presenting with chronic stable IHD, non ST-elevation acute coronary syndrome, and ST-elevation myocardial infarction. It also addresses the clinical challenges met when considering PCI in this cohort and the ongoing need for research and development to further improve outcomes in these challenging patients.

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.

Comparison of diagnostic accuracy of combined assessment using adenosine stress computed tomography perfusion + computed tomography angiography with transluminal attenuation gradient + computed tomography angiography against invasive fractional flow reserve.

OBJECTIVES: The goal of this study was to compare the diagnostic accuracy of combined computed tomography perfusion (CTP) + computed tomography angiography (CTA), transluminal attenuation gradient by 320-detector row computed tomography (TAG320) + CTA, and CTP + TAG320 + CTA (multidetector computed tomography-integrated protocol [MDCT-IP]) assessment in predicting significant fractional flow reserve (FFR). BACKGROUND: CTA has limited specificity for predicting functionally significant stenoses. Novel CT techniques, including adenosine stress CTP and TAG320, may improve the diagnostic accuracy of CTA. METHODS: CTA, CTP, and TAG320 were assessed using 320-detector row MDCT. Patients who underwent CTA, CTP, and FFR assessment on invasive coronary angiography were included. CTP was assessed using the visual perfusion assessment. TAG320 was defined as the linear regression coefficient between luminal attenuation and axial distance. A TAG320 cutoff value of -15.1 HU/10 mm as previously described was defined as significant. Functionally significant coronary stenosis was defined as FFR ≤0.8. RESULTS: The cohort included 75 patients (age 64.1 ± 10.8 years, 52 men) and 44 (35%) FFR-significant vessels. In 127 vessels, CTA predicted FFR-significant stenosis with 89% sensitivity and 65% specificity compared with MDCT-IP, which showed 88% sensitivity and 83% specificity. In 97 vessels in which the results of all techniques were available, TAG320 + CTA (area under the curve [AUC] = 0.844) and CTP + CTA (AUC = 0.845) had comparable per-vessel diagnostic accuracy (p = 0.98). The diagnostic accuracy of MDCT-IP (AUC = 0.91) was superior to TAG320 + CTA or CTP + CTA (p = 0.01). CONCLUSIONS: In vessels without significant calcification or artefact, TAG320 + CTA and CTP + CTA provide comparable diagnostic accuracy for functional assessment of coronary artery stenosis. MDCT-IP may provide the best diagnostic accuracy for functional assessment of coronary artery stenosis.

320-row CT coronary angiography predicts freedom from revascularisation and acts as a gatekeeper to defer invasive angiography in stable coronary artery disease: a fractional flow reserve-correlated study.

OBJECTIVES: To determine the accuracy of 320-row multidetector coronary computed tomography angiography (M320-CCTA) to detect functional stenoses using fractional flow reserve (FFR) as the reference standard and to predict revascularisation in stable coronary artery disease. METHODS: One hundred and fifteen patients (230 vessels) underwent M320-CCTA and FFR assessment and were followed for 18 months. Diameter stenosis on invasive angiography (ICA) and M320-CCTA were assessed by consensus by two observers and significant stenosis was defined as ≥50%. FFR ≤0.8 indicated functionally significant stenoses. RESULTS: M320-CCTA had 94% sensitivity and 94% negative predictive value (NPV) for FFR ≤0.8. Overall accuracy was 70%, specificity 54% and positive predictive value 65%. On receiver operating characteristic (ROC) curve analysis, the area under the curve (AUC) for CCTA to predict FFR ≤0.8 was 0.74 which was comparable with ICA. The absence of a significant stenosis on M320-CCTA was associated with a 6% revascularisation rate. M320-CCTA predicted revascularisation with an AUC of 0.71 which was comparable with ICA. CONCLUSIONS: M320-CCTA has excellent sensitivity and NPV for functional stenoses and therefore may act as an effective gatekeeper to defer ICA and revascularisation. Like ICA, M320-CCTA lacks specificity for functional stenoses and only has moderate accuracy to predict the need for revascularisation. KEY POINTS: • Important information about the heart is provided by 320-row multidetector CT coronary angiography (M320-CCTA). • M320-CCTA accurately detects and excludes functional stenoses determined by fractional flow reserve (FFR). • Non-significant stenoses on M320-CCTA associated with fewer cardiac events and less revascularisation. • M320-CCTA may act as a gatekeeper for invasive angiography and inappropriate revascularisation. • Like ICA, M320-CCTA only has moderate accuracy to predict vessels requiring revascularisation.

Pre-hospital 12 lead ECG to triage ST elevation myocardial infarction and long term improvements in door to balloon times: The first 1000 patients from the MonAMI project.

BACKGROUND: Pre-hospital ECG is one strategy to improve door to balloon times (D2BT), however its long term effectiveness to sustain reductions in D2BT has not been evaluated. METHODS: From 2007 to 2011 we conducted a prospective interventional study involving 1000 patients undergoing primary PCI (PPCI) at a single tertiary referral institution to determine the long term impact of pre-hospital 12 lead ECG on D2BT. RESULTS: The median D2BT of patients (n=414) who underwent PPCI following field 12-lead ECG was 54 min [IQR: 37-71 min] compared to the median time of a contemporary group (n=586) undergoing PPCI during the same period but not presenting via field triage of 100 min [74-134] (p<0.001). The proportion of patients who achieved a D2BT of ≤90 min in the pre-hospital ECG group was greater than that in the contemporary group (90% vs 42%, p<0.001). A comparison of the first 250 patients compared to subsequent 250 patient blocks showed no change in D2BT. CONCLUSIONS: Introduction of pre-hospital ECG in the triage of STEMI resulted in a sustained reduction in D2BT.

In-stent thrombosis due to neoatherosclerosis: insight from optical coherence tomography.

Neoatherosclerosis is one of the multiple mechanisms that cause stent thrombosis, which is one of the rare but severe complications of drug-eluting stent implantation. This case study highlights the use of optical coherence tomography in identifying the precise mechanism of the stent thrombosis, which helped guide the appropriate intervention.