Eliminate LDL cholesterol after heart attack but only for a while.

There is a clear demonstration of the inverse linear correlation between LDL cholesterol levels and clinical benefit. However, the timing of the action of lipid-lowering drugs is not clear. According to animal studies with recombinant lipoprotein A-1, the composition of atherosclerosis changes within 40 h (with variations in lipid and inflammatory contents). Progression-regression studies of atherosclerosis in humans confirm the data, highlighting a rapid change in the plaque over 5 weeks. The data are also in line with what emerges from the survival curves of the old study comparing atorvastatin 80 mg vs. placebo (Myocardial Ischaemia Reduction with Aggressive Cholesterol Lowering). The spacing of the curves occurs after only 4 weeks, indicating the precociousness of the favourable effects of powerful statins. Finally, a recent Odyssey post hoc analysis compared the risk of cardiac death and coronary revascularization between a group in which alirocumab lowered LDL cholesterol to below 15 mg (Group 1 and in which the drug was therefore stopped) against the subjects in the placebo group (Group 2), applying a propensity score matching. The primary endpoint occurred in a lower percentage of patients in Group 1 (6.4 vs. 8.4%). Furthermore, patients in Group 1 had a significantly lower hazard ratio (HR) for major adverse cardiovascular events [0.72; 95% confidence interval (CI) 0.51-0.997; P = 0.047] compared with the entire alirocumab group vs. placebo (HR 0.85; 95% CI 0.78-0.93; P < 0.001). According to these preliminary observations, aggressive and early treatment of hypercholesterolaemia in subjects with acute coronary syndrome translates into improved clinical results compared with a strategy that provides for more gradual control. These data will need to be confirmed through further prospective clinical studies and ideally with early conducted atherosclerosis regression studies.

Controversy in cardiology: clopidogrel or acetylsalicylic acid in the treatment of chronic coronary syndromes?

Secondary prevention of patients with chronic coronary syndrome is based on the long-term use of a single anti-aggregating drug which is traditionally represented by acetylsalicylic acid (ASA) in light of the results of studies and meta-analyses which have demonstrated a clear anti-ischaemic efficacy against of an acceptable increase in the risk of bleeding, especially intracranial and gastrointestinal bleeding. The availability of drugs such as clopidogrel, which inhibits platelet activity through the P2Y12 receptor pathway, has called into question this paradigm, also in consideration of the fact that the scientific evidence that supports the use of ASA in secondary prevention is based on dated studies with some limitations. Over the last few years, randomized trials have demonstrated how clopidogrel has an efficacy profile comparable to that of ASA and a safety profile that is sometimes even better. In light of the new evidence, it is therefore legitimate to ask whether in this clinical scenario, ASA should still be considered the drug of choice or whether clopidogrel could represent the preferable alternative.

Intracoronary imaging to guide percutaneous coronary intervention: from evidence to guidelines.

Despite notable advances in devices and techniques, percutaneous coronary intervention (PCI) is still affected by a substantial number of complications and failure rates. Over the years, the use of intracoronary imaging (ICI) has dramatically improved the understanding of mechanical and technical factors related to successful and failed PCI, becoming a mainstay in complex trans-catheter interventions. However, ICI modalities are invasive, time-consuming, and costly, and a net clinical benefit needs to be shown in order to recommend their routine use in clinical practice. In the past, the lack of evidence from randomized trials has been reflected in the scepticism shown by international guidelines. The recent publication of large randomized clinical trials conducted worldwide has provided new evidence regarding the clinical usefulness of ICI guidance in PCI. The consistent reduction of adverse events achieved in these trials, also demonstrated in an updated meta-analysis, suggested that the use of ICI in PCI is compelling to achieve optimal technical results and better outcomes, especially in complex high-risk interventions. Also considering the burden of information provided by ICI on coronary artery disease, looking from the inside seems today an opportunity that modern cardiology cannot ignore anymore.

OCT-Guided versus Angiography-Guided Coronary Stent Implantation in Complex Lesions: An ILUMIEN IV Substudy.

BACKGROUND: ILUMIEN IV was the first large-scale, multicenter, randomized trial comparing optical coherence tomography (OCT)-guided versus angiography-guided stent implantation in patients with high-risk clinical characteristics and/or complex angiographic lesions. OBJECTIVE: Here, we aimed to specifically examine outcomes in the complex angiographic lesions subgroup. METHODS: From the original trial population (n=2487), high-risk patients without complex angiographic lesions were excluded (n=514). Complex angiographic lesion characteristics included 1) long or multiple lesions with intended total stent length ≥28 mm; 2) bifurcation lesion with intended two-stent strategy; 3) severely calcified lesion; 4) chronic total occlusion; or 5) in-stent restenosis. The study endpoints were 1) final minimal stent area (MSA); 2) 2-year composite of serious major adverse cardiovascular events (MACE; cardiac death, target-vessel myocardial infarction (MI), or stent thrombosis); and 3) 2-year effectiveness, defined as target-vessel failure (TVF), a composite of cardiac death, target-vessel MI, or ischemia-driven target-vessel revascularization. RESULTS: The post-PCI MSA was larger in the OCT- (n=992) versus angiography-guided (n=981) group (5.56±1.95 versus 5.26±1.81mm2; difference, 0.30; 95% confidence interval [CI], 0.14-0.47; P<0.001). Compared with angiography-guided PCI, OCT-guided PCI resulted in a lower risk of serious MACE (3.1% versus 4.9%; hazard ratio [HR], 0.63; 95% CI, 0.40-0.99; P=0.04). TVF was not significantly different between groups (7.3% versus 8.8%; HR, 0.82; 95% CI, 0.59-1.12; P=0.20). CONCLUSIONS: In complex angiographic lesions, OCT-guided PCI led to a larger MSA and reduced the serious MACE composite of cardiac death, target-vessel MI, or stent thrombosis compared with angiography-guided PCI at 2 years, but did not significantly improve TVF.

[Optimizing the care management pathway of patients with ischemia and non-obstructive coronary arteries]. / Ottimizzazione del percorso clinico-gestionale del paziente con ischemia in assenza di malattia coronarica ostruttiva.

Ischemia with non-obstructive coronary arteries (INOCA) is defined by the coexistence of anginal symptoms and demonstrable ischemia, with no evidence of obstructive coronary arteries. The underlying mechanism of INOCA is coronary microvascular dysfunction with or without associated vasospasm. INOCA patients have recurrent symptoms, functional limitations, repeated access to the emergency department, impaired quality of life and a higher incidence of cardiovascular events than the general population. Although well described in chronic coronary syndrome guidelines, INOCA remains underdiagnosed in clinical practice because of insufficient awareness, lack of accurate diagnostic tools, and poorly standardized and consistent definitions to diagnose, both invasively and non-invasively, coronary microvascular dysfunction.To disseminate current scientific evidence on INOCA as a distinct clinical entity, during 2022 we conducted at 30 cardiology units all over the country a clinical practice improvement initiative, with the aim of developing uniform and shared management pathways for INOCA patients across different operational settings. The present document highlights the outcomes of this multidisciplinary initiative.

Leptin as predictor of cardiovascular events and high platelet reactivity in patients undergoing percutaneous coronary intervention.

BACKGROUND AND AIMS: Leptin is a hormone involved in the regulation of food intake. Previous studies suggested an interplay between leptin, platelet aggregation, and cardiovascular outcome but this issue was not investigated in vivo in patients treated with percutaneous coronary intervention (PCI). We designed a study to evaluate the possible relation between leptin, cardiovascular outcome, and platelet reactivity (PR) in patients undergoing PCI. METHODS: 155 PCI patients had preprocedural measurements of PR and leptin plasma levels. The latter were assessed by ELISA. Hyperleptinemia was defined as leptin levels ≥14 ng/ml. PR was evaluated by the VerifyNowP2Y12 assay and expressed as P2Y12 reaction units (PRU). Patients were divided into three groups based on PR values and defined as low (LPR), normal (NPR), and high (HPR). Patients were followed for up 8 years. The primary endpoint was the incidence of Major Acute Cardiac Events (MACE) at long-term follow-up according to leptin groups. Secondary endpoints were the evaluation of leptin levels according to PR groups and the incidence of periprocedural myocardial infarction (PMI) according to leptin groups. RESULTS: Long-term follow-up was completed in 140 patients. Patients with hyperleptinemia experienced a higher MACE rate than the normoleptinemic group (HR 2.3; CI 95% 1.14-4.6, P = 0.02). These results remained unchanged after adjusting for Body Mass Index, hypertension, and gender. Leptin levels were significantly different among groups of PR (P = 0.047). Leptin levels were higher in the HPR group (12.61 ± 16.58 ng/ml) compared to the LPR group (7.83 ± 8.87 ng/ml, P = 0.044) and NPR group (7.04 ± 7.03 ng/ml, P = 0.01). The rate of PMI was higher in hyperleptinemia patients (15.1% vs. 6.5%, P = 0.22). CONCLUSIONS: This study suggests that high leptin levels are associated with a worse clinical outcome in patients undergoing PCI and with HPR. Further studies are needed to define better the pathophysiological pathways underlying this association.

Coronary Plaque Characteristics Associated With Major Adverse Cardiovascular Events in Atherosclerotic Patients and Lesions: A Systematic Review and Meta-Analysis.

BACKGROUND: The clinical value of high-risk coronary plaque characteristics (CPCs) to inform intensified medical therapy or revascularization of non-flow-limiting lesions remains uncertain. OBJECTIVES: The authors performed a systematic review and meta-analysis to study the prognostic impact of CPCs on patient-level and lesion-level major cardiovascular adverse events (MACE). METHODS: Thirty studies (21 retrospective, 9 prospective) with 30,369 patients evaluating the association of CPCs with MACE were included. CPCs included high plaque burden, low minimal lumen area, thin cap fibroatheroma, high lipid core burden index, low-attenuation plaque, spotty calcification, napkin ring sign, and positive remodeling. RESULTS: CPCs were evaluated with the use of intracoronary modalities in 9 studies (optical coherence tomography in 4 studies, intravascular ultrasound imaging in 3 studies, and near-infrared spectroscopy intravascular ultrasound imaging in 2 studies) and by means of coronary computed tomographic angiography in 21 studies. CPCs significantly predicted patient-level and lesion-level MACE in both unadjusted and adjusted analyses. For most CPCs, accuracy for MACE was modest to good at the patient level and moderate to good at the lesion level. Plaques with more than 1 CPC had the highest accuracy for lesion-level MACE (AUC: 0.87). Because the prevalence of CPCs among plaques was low, estimated positive predictive values for lesion-level MACE were modest. Results were mostly consistent across imaging modalities and clinical presentations, and in studies with prevailing hard outcomes. CONCLUSIONS: Characterization of CPCs identifies high-risk atherosclerotic plaques that place lesions and patients at risk for future MACE, albeit with modest sensitivity and positive predictive value (Coronary Plaque Characteristics Associated With Major Adverse Cardiovascular Events Among Atherosclerotic Patients and Lesions; CRD42021251810).

Optical Coherence Tomography-Guided versus Angiography-Guided PCI.

BACKGROUND: Data regarding clinical outcomes after optical coherence tomography (OCT)-guided percutaneous coronary intervention (PCI) as compared with angiography-guided PCI are limited. METHODS: In this prospective, randomized, single-blind trial, we randomly assigned patients with medication-treated diabetes or complex coronary-artery lesions to undergo OCT-guided PCI or angiography-guided PCI. A final blinded OCT procedure was performed in patients in the angiography group. The two primary efficacy end points were the minimum stent area after PCI as assessed with OCT and target-vessel failure at 2 years, defined as a composite of death from cardiac causes, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization. Safety was also assessed. RESULTS: The trial was conducted at 80 sites in 18 countries. A total of 2487 patients underwent randomization: 1233 patients were assigned to undergo OCT-guided PCI, and 1254 to undergo angiography-guided PCI. The minimum stent area after PCI was 5.72±2.04 mm2 in the OCT group and 5.36±1.87 mm2 in the angiography group (mean difference, 0.36 mm2; 95% confidence interval [CI], 0.21 to 0.51; P<0.001). Target-vessel failure within 2 years occurred in 88 patients in the OCT group and in 99 patients in the angiography group (Kaplan-Meier estimates, 7.4% and 8.2%, respectively; hazard ratio, 0.90; 95% CI, 0.67 to 1.19; P = 0.45). OCT-related adverse events occurred in 1 patient in the OCT group and in 2 patients in the angiography group. Stent thrombosis within 2 years occurred in 6 patients (0.5%) in the OCT group and in 17 patients (1.4%) in the angiography group. CONCLUSIONS: Among patients undergoing PCI, OCT guidance resulted in a larger minimum stent area than angiography guidance, but there was no apparent between-group difference in the percentage of patients with target-vessel failure at 2 years. (Funded by Abbott; ILUMIEN IV: OPTIMAL PCI ClinicalTrials.gov number, NCT03507777.).

Clinical impact of OCT-derived suboptimal stent implantation parameters and definitions.

AIMS: Despite growing evidence supporting the clinical utility of optical coherence tomography (OCT) guidance during percutaneous coronary interventions (PCIs), there is no common agreement as to the optimal stent implantation parameters that enhance clinical outcome. METHODS AND RESULTS: We retrospectively examined the predictive accuracy of suboptimal stent implantation definitions proposed from the CLI-OPCI II, ILUMIEN-IV OPTIMAL PCI, and FORZA studies for the long-term risk of device-oriented cardiovascular events (DoCE) in the population of large all-comers CLI-OPCI project. A total of 1020 patients undergoing OCT-guided drug-eluting stent implantation in the CLI-OPCI registry with a median follow-up of 809 (quartiles 414-1376) days constituted the study population. According to CLI-OPCI II, ILUMIEN-IV OPTIMAL PCI, and FORZA criteria, the incidence of suboptimal stent implantation was 31.8%, 58.1%, and 57.8%, respectively. By multivariable Cox analysis, suboptimal stent implantation criteria from the CLI-OPCI II [hazard ratio 2.75 (95% confidence interval 1.88-4.02), P < 0.001] and ILUMIEN-IV OPTIMAL PCI [1.79 (1.18-2.71), P = 0.006] studies, but not FORZA trial [1.11 (0.75-1.63), P = 0.597], were predictive of DoCE. At long-term follow-up, stent edge disease with minimum lumen area <4.5 mm2 [8.17 (5.32-12.53), P < 0.001], stent edge dissection [2.38 (1.33-4.27), P = 0.004], and minimum stent area <4.5 mm2 [1.68 (1.13-2.51), P = 0.011] were the main OCT predictors of DoCE. CONCLUSION: The clinical utility of OCT-guided PCI might depend on the metrics adopted to define suboptimal stent implantation. Uncovered disease at the stent border, stent edge dissection, and minimum stent area <4.5 mm2 were the strongest OCT associates of stent failure.

Effects of Lipid Lowering Therapies on Vulnerable Plaque Features: An Updated Narrative Review of the Literature.

The clinical evidence on the efficacy of lipid lowering therapy in patients with coronary artery disease (CAD) is unequivocally established. However, the effects of these therapies on plaque composition and stability are less clear. The use of intracoronary imaging (ICI) technologies has emerged as a complement to conventional angiography to further characterize plaque morphology and detect high-risk plaque features related to cardiovascular events. Along with clinical outcomes studies, parallel imaging trials employing serial evaluations with intravascular ultrasound (IVUS) have shown that pharmacological treatment has the capacity to either slow disease progression or promote plaque regression, depending on the degree of lipid lowering achieved. Subsequently, the introduction of high-intensity lipid lowering therapy led to much lower levels of low-density lipoprotein cholesterol (LDL-C) levels than achieved in the past, resulting in greater clinical benefit. However, the degree of atheroma regression showed in concomitant imaging trials appeared more modest as compared to the magnitude of clinical benefit accrued from high-intensity statin therapy. Recently, new randomized trials have investigated the additional effects of achieving very low levels of LDL-C on high-risk plaque features-such as fibrous cap thickness and large lipid accumulation-beyond its size. This paper provides an overview of the currently available evidence of the effects of moderate to high-intensity lipid lowering therapy on high-risk plaque features as assessed by different ICI modalities, reviews data supporting the use of these trials, and analyse the future perspectives in this field.

Prediction of new onset atrial fibrillation in patients with acute coronary syndrome undergoing percutaneous coronary intervention using the C2HEST and mC2HEST scores: A report from the multicenter REALE-ACS registry.

BACKGROUND: New onset atrial fibrillation (NOAF) is associated with worse clinical outcomes after acute coronary syndrome (ACS). Identification of ACS patients at risk of NOAF remains challenging. To test the value of the simple C2HEST score for predicting NOAF in patients with ACS. METHODS: We studied patients from the prospective ongoing multicenter REALE-ACS registry of patients with ACS. NOAF was the primary endpoint of the study. The C2HEST score was calculated as coronary artery disease or chronic obstructive pulmonary disease (1 point each), hypertension (1 point), elderly (age ≥ 75 years, 2 points), systolic heart failure (2 points), thyroid disease (1 point). We also tested the mC2HEST score. RESULTS: We enrolled 555 patients (mean age 65.6 ± 13.3 years; 22.9% women), of which 45 (8.1%) developed NOAF. Patients with NOAF were older (p < 0.001) and had more prevalent hypertension (p = 0.012), chronic obstructive pulmonary disease (p < 0.001) and hyperthyroidism (p = 0.018). Patients with NOAF were more frequently admitted with STEMI (p < 0.001), cardiogenic shock (p = 0.008), Killip class ≥2 (p < 0.001) and had higher mean GRACE score (p < 0.001). Patients with NOAF had a higher C2HEST score compared with those without (4.2 ± 1.7 vs 3.0 ± 1.5, p < 0.001). A C2HEST score > 3 was associated with NOAF occurrence (odds ratio 4.33, 95% confidence interval 2.19-8.59, p < 0.001). ROC curve analysis showed good accuracy of the C2HEST score (AUC 0.71, 95%CI 0.67-0.74) and mC2HEST score (AUC 0.69, 95%CI 065-0.73) in predicting NOAF. CONCLUSIONS: The simple C2HEST score may be a useful tool to identify patients at higher risk of developing NOAF after presentation with ACS.

Sudden cardiac death in ischaemic heart disease: coronary thrombosis or myocardial fibrosis?

The mechanisms underlying sudden cardiac death (SCD) in patients with ischaemic heart disease (IHD) caused by coronary atherosclerosis are not yet clarified. For decades, acute coronary causes have been sought as the main triggers of SCD in these patients. In fact, angiographic and pathological studies in cardiac arrest survivors and SCD victims, respectively, consistently show that acute plaque events occur in ∼50% of SCD of patients with IHD. Among the acute events, plaque rupture and erosion triggering acute coronary thrombosis remain the main substrates; however, a significant percentage of plaque haemorrhage (20%) is identified by pathological studies. Its role in acute coronary thrombosis is unknown and deserves future intravascular imaging developments. In the remaining 50% of SCD, the atherosclerotic coronary disease shows the characteristics of structural stability. More recent studies have focused attention not only on the coronary tree and on the search for acute complications of atherosclerotic plaques but also on myocardial tissue, identifying replacement and patchy fibrosis as the most frequent findings in the post-mortem hearts of these patients, a feature followed by cardiac hypertrophy, as assessed by the heart weight, usually associated with fibrosis. The possibility of characterizing myocardial fibrosis in vivo, besides confirming the pathological data, now offers new risk stratification perspectives to prevent SCD in IHD, alongside the consolidated secondary prevention criteria based on left ventricular dysfunction.

Spontaneous coronary artery dissection: an unpredictable event.

Spontaneous coronary artery dissection (SCAD) is an under-recognized cause of acute coronary syndrome that predominantly affects women in adulthood and is the leading cause of acute myocardial infarction in pregnancy. The most common clinical presentation is ST-segment elevation myocardial infarction (STEMI) or non-STEMI, followed by cardiogenic shock (∼2%), sudden cardiac death (0.8% in autopsy series), cardiac arrest, ventricular arrhythmias (∼5%), and Takotsubo syndrome. The prevalence of SCAD in the general population is largely uncertain due to underdiagnosis. Oral contraceptives, post-menopausal therapy, and infertility treatments are recognized associated factors. The pathological substrates (fibromuscular dysplasia) and triggers (especially emotional stress) are commonly present in affected women. The few cases with a precise genetic aetiology occur in the context of syndromic and non-syndromic connective tissue diseases. The only true certainty in SCAD is the overwhelming prevalence in women. The first event as well as the recurrence (up to 30%, which varies depending on the definition) is largely unpredictable. The treatment strategy is highly individualized and requires extensive additional study in order to optimize outcomes and prevent major adverse cardiovascular events in affected individuals. We have known about SCAD for nearly a century, but we still do not know how best to prevent, diagnose, and treat it, making SCAD a highly important and unmet clinical need.

Secondary prevention and follow-up of patients with ACS and not-at-target LDL: An Italian real-world retro-prospective analysis by the inertia group.

Background: In patients with recent ACS, the latest ESC/EAS guidelines for management of dyslipidaemia recommend intensification of LDL-C-lowering therapy. Objective: Report a real-world picture of lipid-lowering therapy prescribed and cholesterol targets achieved in post-ACS patients before and after a specific educational program. Methods: Retrospective data collection prior to the educational course and prospective data collection after the course of consecutive very high-risk patients with ACS admitted in 2020 in 13 Italian cardiology departments, and with a non-target LDL-C level at discharge. Results: Data from 336 patients were included, 229 in the retrospective phase and 107 in the post-course prospective phase. At discharge, statins were prescribed in 98.1% of patients, alone in 62.3% of patients (65% of which at high doses) and in combination with ezetimibe in 35.8% of cases (52% at high doses). A significant reduction was obtained in total and LDL cholesterol (LDL-C) from discharge to the first control visit. Thirty-five percent of patients achieved a target LDL-C <55 mg/dL according to ESC 2019 guidelines. Fifty percent of patients achieved the <55 mg/dL target for LDL-C after a mean of 120 days from the ACS event. Conclusions: Our analysis, though numerically and methodologically limited, suggests that management of cholesterolaemia and achievement of LDL-C targets are largely suboptimal and need significant improvement to comply with the lipid-lowering guidelines for very high CV risk patients. Earlier high intensity statin combination therapy should be encouraged in patients with high residual risk.

OCT guided vs. COmplete pci in patieNts with sT segment elevation myocArdial infarCtion and mulTivessel disease: OCT-CONTACT RCT.

BACKGROUND: In patients with ST-segment elevation myocardial infarction (STEMI), percutaneous coronary intervention (PCI) of the culprit lesion significantly reduces the risk of cardiovascular death. However, the management of non-culprit lesions in patients with the multivessel disease remains a matter of debate in this setting. It's still unclear if a morphological OCT-guided approach, identifying coronary plaque instability, may provide a more specific treatment compared with a standard angiographic/functional approach. METHODS: OCT-Contact is a prospective, multicenter, open-label, non-inferiority randomized controlled trial. Patients with STEMI with successful primary PCI of the culprit lesion will be enrolled after the index PCI. Patients will be deemed eligible if a critical coronary lesion other than the culprit (associated with a diameter of stenosis ≥50%) will be identified during the index angiography. Patients will be randomized in a 1:1 fashion to OCT-guided PCI of non-culprit lesions (Group A) vs. complete PCI (Group B). PCI in group A will be undertaken according to criteria of plaque vulnerability, while in group B the use of fractional flow reserve will be left at the operators' discretion. Major-adverse cardiovascular events (MACE) are a composite of all-cause mortality, non-fatal myocardial infarction (MI) (excluding peri-procedural MI), unplanned revascularization, and NYHA IV heart failure) will be the primary efficacy outcome. Single components of MACE along with cardiovascular mortality will be the secondary endpoints. . Safety endpoints will embrace worsening of renal failure, procedural complications, and bleedings. Patients will be followed for 24 months after randomization. RESULTS: A sample size of 406 patients (203 per group) is required to provide the analysis an 80% power to detect a non-inferiority in the primary endpoint with an alpha error set at 0.05 and a non-inferiority limit of 4%. CONCLUSIONS: A morphological OCT-guided approach may be a more specific treatment compared with the standard angiographic/functional approach in non-culprit lesions of STEMI patients.

Comparison between different approaches to evaluate fibrous cap thickness in sequential optical coherence tomography studies.

BACKGROUND: In this in-vivo human study we tested the reproducibility for optical coherence tomography (OCT) assessment of lumen area (LA) and plaque components measurements, such as lipid arc extension and fibrous cap thickness (FCt). METHODS: We tested the variability of LA, lipid arc and FCt assessments in two repeated OCT pullbacks from the same diseased coronary segment matched using fiduciary anatomical landmarks. In particular, for the reliability of minimal FCt measurement we compared four different approaches based on continuous (longitudinal) or segmental (spot) individuation of smaller thickness: 1) comparison of single minimal FCt individuated alongside all plaque extension in the two pullbacks (Longitudinal (L)-spot minimal FCt value); 2) comparison of the mean FCt values of the plaque in the two pullbacks (L-plot mean FCt value); 3) comparison between the single minimal FCt value obtained in the first pullback and the single FCt obtained in the matched CS of second pullback (L-spot CS matched FCt value); 4) comparison of measurements obtained by visual selection of CS with minimal FCt s in the two pullbacks (single-spot minimal FCt value). RESULTS: From the paired analyses of 20 non culprit lesions (accounting for a total of 387 matched CS), we found a suboptimal in-segment correlation for LA (Intra-Class Coefficient [ICC] 0.731), but a good in-segment correlation for lipid arc (ICC 0.963). Regarding FCt measurement, a high reproducibility was obtained applying continuous assessment; in particular, the best correlation was observed with L-spot minimal FCt value and the L-plot mean FCt (ICC 0.893 and 0.952, respectively) with small inter-pullback differences (confidence intervals less than 0.04 mm). CONCLUSIONS: In this methodological study we observed a good reproducibility for quantitative plaque measurements with OCT confirming its reliability for serial assessment. In particular, longitudinal measurement in multiple adjacent frames seems to be the more accurate and reproducible approach for sequential FCt assessment.