Comparison of Angiographic and Intravascular Ultrasound Vessel Measurements in Infra-Popliteal Endovascular Interventions: The Below-the-Knee Calibration Study.

BACKGROUND: Endovascular revascularization (ER) via percutaneous transluminal angioplasty (PTA) and stenting are viable options for revascularization in below-the-knee (BTK) peripheral arterial disease. Two-dimensional angiography has been the standard of practice for estimating vessel size and selecting treatment devices during ER. However, in other vascular territories, intravascular ultrasound (IVUS) offers better visualization of the lumen dimensions. PURPOSE: To compare angiographic and intravascular ultrasound reference vessel (lumen) measurements in below-the-knee peripheral artery interventions. METHODS: Twenty consecutive patients were enrolled in the BTK Calibration study from 2 sites in the United States and Australia. Patients with at least one diseased segment in a native infra-popliteal artery (below-the-knee) and a clinical indication for endovascular therapy (EVT) were included with no limitations with regard to vessel diameter or lesion length. Digital subtraction angiography and IVUS imaging were collected pre- and post-PTA and images were sent to an independent core lab for standardized quantitative analysis of the normal-looking reference vessel dimensions when available. The results were presented as least square means with 95% confidence intervals and a p-value of <0.05 was considered significant. RESULTS: The overall (N = 19) mean reference vessel diameter for QVA was 2.98 ± 1.24 mm vs. 3.47 ± 0.72 mm for IVUS (mean difference was -0.50 mm, (95% CI: -0.80, -0.20; p = 0.14). As expected, in the proximal segments (N = 12), the mean reference vessel diameters were larger: for QVA, it was 3.17 ± 1.34 mm vs. 3.55 ± 0.76 mm in IVUS, (mean difference was -0.38 mm, (95% CI: -0.79, 0.03; p = 0.40); while in the distal segments (N = 7), mean reference vessel diameters were smaller: for QVA, it was 2.64 ± 1.06 mm vs. 3.33 ± 0.67 mm in IVUS, (mean difference was -0.69 mm, (95% CI: -1.04, 0.34; p = 0.17). We observed a greater degree of acute gain in cases where the treatment balloon size correlated with the IVUS measured reference size. CONCLUSION: Angiography underestimates infrapopliteal reference vessel lumen size even when quantitatively assessed. Adjunctive IVUS imaging use in guiding BTK procedures could help ensure adequate sizing and possibly impact immediate post-procedure indices.

Optical Coherence Tomography based treatment approach for patients with Acute Coronary Syndrome.

INTRODUCTION: Areas covered:In this review, we outline the underlying causes of acute coronary syndrome (ACS) as evaluated by optical coherence tomography (OCT). We report both the definitions of each mechanism and its frequency as reported in the literature to date. Finally, we present an algorithm based on the findings in the review that gives an outlined approach to perform intervention on ACS patients.Expert opinion:Although the most common and most accepted intervention in ACS cases is stent implantation, data suggest a stentless approach in cases of plaque erosion, which generally occurs in younger patients presenting with an acute coronary syndrome that have TIMI flow of 2/3 and either a small or large burden of thrombus and underlying stenosis of less than 50%.

Comparison of Patterns of Coronary Artery Disease in Patients With Heart Failure by Cardiac Amyloidosis Status.

BACKGROUND/PURPOSE: The aim of this study is to characterize the pattern and the severity of coronary artery lesions in cardiac amyloidosis. METHODS: We retrospectively compared patients with heart failure who tested positive (i.e., biopsy or gene tests - HF/CA+) against those who tested negative (HF/CA-) for cardiac amyloidosis. Groups were compared demographically and angiographically for qualitative and quantitative variables to determine patterns of involvement in the major epicardial coronary vessels. RESULTS: The study included 110 heart failure patients, of whom 55 patients (88 lesions) were in the HF/CA+ group, and 55 patients (66 lesions) were HF/CA-. Despite the advanced age of HF/CA+ patients (74.5 ± 11.0 years vs. 54.1 ± 15.0 years; p = 0.05), no severe calcification was found in the HF/CA+ group (0.0% vs. 4.5%; p = 0.018). The HF/CA+ group also had fewer ostial lesions (3.4% vs. 15.1%; p = 0.0095) and a higher, albeit not significant, Thrombolysis in Myocardial Infarction frame count (30.4 ± 12.6 vs. 26.6 ± 11 frames; p = 0.06). In the HF/CA+ group, men had a significant number of tandem lesions compared to women (14.5% vs 0.0%, p = 0.02). CONCLUSIONS: Overall, heart failure patients with cardiac amyloidosis were older but were found to have less calcified lesions, less ostial involvement, and a reduced anterograde coronary blood flow. This is the first report examining coronary lesions in heart failure patients with cardiac amyloidosis.

Impact of two formulas to calculate percentage diameter stenosis of coronary lesions: from stenosis models (phantom lesion model) to actual clinical lesions.

Percentage diameter stenosis (%DS) by angiography is still commonly used to determine luminal obstruction of coronary artery disease (CAD) lesions. While visual estimation of %DS is widespread, because of high inter-operator variability, quantitative coronary arteriography (QCA) analysis is the gold standard. There are two %DS formulas: %DS1 averages the proximal and distal reference vessel diameter (RVD); %DS2 interpolates the RVD. This study aims to evaluate the difference between %DS assessed by QCA in two datasets, phantom lesion models and CAD patients. Ten phantom lesion models (PLMs) and 354 CAD lesions from the FIRST trial were assessed by QCA. In the latter, two scenarios were assessed: Scenario A (worst view), the most common approach in the clinical setting; and Scenario B (average of two complementary views), the standard core-laboratory analysis. In the PLMs, %DS1 and %DS2 mean ± standard deviation (median) was 58.5 ± 21.7 (61.6) and 58.7 ± 21.6 (61.8), respectively, with a signed difference of - 0.2% ± 0.3% (- 0.1%). In Scenario A, the mean %DS1 was 43.8 ± 9.1 (43.3) and 44.0 ± 9.1 (42 .9) in %DS2. In Scenario B, the mean %DS1 was 45.3 ± 8.8 (45.1) and 45.5 ± 9.0 (45.1) in %DS2. The signed difference was - 0.2% ± 2.4% (0.0%) and - 0.2% ± 2.1% (0.0%) in Scenario A and B, respectively. These differences between formulas ranged from - 1.2 to 0.5% for the phantom cases compared to - 17.7% to 7.7% in Scenario A and to - 15.5% to 7.1% in Scenario B. Although the overall means of the formulas provide similar results, significant lesion-level differences are observed. The use of the worst view versus the average of two views provided similar results.

Effect of Statin Therapy on Fibrous Cap Thickness in Coronary Plaque on Optical Coherence Tomography　- Review and Meta-Analysis.

BACKGROUND: Statin therapy has been shown to result in coronary plaque regression, but the relationship between statin use and stabilization of coronary plaque has not been elucidated. We conducted a systematic review and meta-analysis to evaluate the effect of statin therapy on fibrous cap thickness (FCT) on optical coherence tomography (OCT).Methods and Results:Nine OCT studies (6 randomized controlled trials and 3 observational studies) were enrolled with a total of 341 patients (390 lesions). Arms of the studies were grouped according to statin type and/or dose. Random effects meta-analysis was used to estimate a pooled mean change in FCT from baseline to follow-up. The overall effect mean FCT change was 67.7 µm (95% CI: 51.4-84.1, I2=95.0%, P<0.001). All statin groups had an increase in FCT, but the magnitude of the increase differed according to the statin. Two homogeneous subgroups with I2=0 were identified: mean FCT change was 27.8 µm (for subgroup atorvastatin 5 mg and rosuvastatin), and 61.9 µm (for subgroup atorvastatin 20 mg, fluvastatin 30 mg, and pitavastatin 4 mg). On meta-regression modeling, statin therapy alone explained most of the change in FCT. CONCLUSIONS: Statin therapy induced a significant increase in FCT as assessed on OCT, independent of coronary risk factors and other medications.

Clinical outcomes of complete revascularization using either angiography-guided or fractional flow reserve-guided drug-eluting stent implantation in non-culprit vessels in ST elevation myocardial infarction patients: insights from a study based on a systematic review and meta-analysis.

Current guidelines recommend that percutaneous coronary intervention (PCI) should be restricted to the culprit vessel in ST elevation myocardial infarction (STEMI) patients with multi-vessel disease (MVD) and without cardiogenic shock. However, newer data suggests that performing complete revascularization (CR) in MVD patients may lead to better outcomes compared to intervention in the culprit vessel only. The aim of this meta-analysis is to examine the available data to determine if CR (using either angio- or fractional flow reserve guidance-FFR) following primary PCI in STEMI patients without cardiogenic shock impacts clinical outcomes. Meta-analysis was performed by conducting a literature search of PubMed from January 2004 to July 2017. Pooled estimates of outcomes, presented as odds ratios (OR) [95% confidence intervals], were generated using random-effect models. A total of 9 studies (3317 patients) were included. CR showed a significant MACE reduction (OR 0.49, 95% CI 0.36-0.66, p < 0.001); All-cause mortality (OR 0.69, 95% CI 0.48-0.98, p = 0.04) and repeat revascularization (OR 0.38, 95% CI 0.28-0.51, p < 0.001) at ≥ 12 months follow-up. The FFR-guiding CR group presented a MACE reduction (odds ratio 0.52, 95% CI 0.30-0.90, p = 0.02) due to a decrease of repeat revascularization (OR 0.41, 95% CI 0.21-0.80, p = 0.009). Overall, performing complete revascularization in STEMI patients showed a MACE reduction, all-cause death and repeat revascularization. Compared to culprit-only revascularization, treating multi-vessel disease in STEMI patients using FFR guidance is associated with decreased incidence of MACE, due to a decreased rate of revascularization.