Periodontitis, Dental Procedures, and Young-Onset Cryptogenic Stroke

Periodontitis is associated with an increased risk of ischemic stroke, and the risk may be particularly high among young people with unexplained stroke etiology. Thus, we investigated in a case-control study whether periodontitis or recent invasive dental treatments are associated with young-onset cryptogenic ischemic stroke (CIS). We enrolled participants from a multicenter case-control SECRETO study including adults aged 18 to 49 y presenting with an imaging-positive first-ever CIS and stroke-free age- and sex-matched controls. Thorough clinical and radiographic oral examination was performed. Furthermore, we measured serum lipopolysaccharide (LPS) and lipotechoic acid (LTA) levels. Multivariate conditional regression models were adjusted for stroke risk factors, regular dentist visits, and patent foramen ovale (PFO) status. We enrolled 146 case-control pairs (median age 41.9 y; 58.2% males). Periodontitis was diagnosed in 27.5% of CIS patients and 20.1% of controls (P < 0.001). In the fully adjusted models, CIS was associated with high periodontal inflammation burden (odds ratio [OR], 95% confidence interval) with an OR of 10.48 (3.18-34.5) and severe periodontitis with an OR of 7.48 (1.24-44.9). Stroke severity increased with the severity of periodontitis, having an OR of 6.43 (1.87-23.0) in stage III to IV, grade C. Invasive dental treatments performed within 3 mo prestroke were associated with CIS, with an OR of 2.54 (1.01-6.39). Association between CIS and invasive dental treatments was especially strong among those with PFO showing an OR of 6.26 (1.72-40.2). LPS/LTA did not differ between CIS patients and controls but displayed an increasing trend with periodontitis severity. Periodontitis and recent invasive dental procedures were associated with CIS after controlling for multiple confounders. However, the role of bacteremia as a mediator of this risk was not confirmed.

Statin use and cardiovascular outcomes after myocardial infarction: a population-based case-control study

Background

Statin therapy is a cornerstone of secondary prevention after myocardial infarction (MI). However, many patients do not use statins.

Purpose

To study the impact of not using statin early after MI on adverse outcomes.

Methods

Consecutive MI patients admitted to 20 Finnish hospitals (n=64,401; median age 71) were retrospectively studied. Statin was not used by 17.1% within 90 days after MI discharge (exposure). Differences in baseline features, comorbidities, revascularization, and other evidence-based medications were balanced with propensity score matching, resulting in 10,051 pairs of patients with and without statin. Median follow-up was 5.9 years.

Results

High-risk patients used statins less frequently. Patients not using statin early after MI had higher all-cause mortality in 1-year (15.8% vs. 11.9%; HR 1.38; CI 1.30–1.46; p&lt;0.0001) and 10-year follow-up (71.1% vs. 65.2%; HR 1.34; CI 1.30–1.39; p&lt;0.0001). The number needed to harm by not using statin was 24.1 at 1-year and 9.5 at 10-years. The cumulative incidence of major adverse cardiovascular event was higher at 1- and 10-years in patients not using statins (sHR 1.15; p&lt;0.0001 for both). Cardiovascular death, new MI, and ischemic stroke were more frequent without early statin. A lack of statin was associated with outcomes regardless of sex, age, atrial fibrillation, dementia, diabetes, heart failure, revascularization, or usage of other evidence-based secondary preventive medications in subgroup analyses.

Conclusions

Lack of statin therapy after MI is associated with adverse outcomes across the spectrum of MI patients. Measures to improve timely statin use after MI are still needed.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Finnish Foundation for Cardiovascular Research, Paavo Nurmi Foundation

Prognostic value of coronary flow capacity derived from [15O]H2O positron emission tomography perfusion imaging

Background

Coronary flow capacity (CFC) is a cross-modality framework integrating hyperemic myocardial blood flow (hMBF) and coronary flow reserve (CFR) to quantify the physiological impact of coronary atherosclerotic disease on vasodilator capacity.

Purpose

This study explores the prognostic value of CFC derived from [15O]H2O positron emission tomography (PET) perfusion imaging in addition to traditional perfusion metrics.

Methods

Quantitative perfusion measurements were obtained from 1300 patients with suspected or known coronary artery disease who underwent [15O]H2O PET imaging. Patients were classified as having myocardial steal, severely reduced CFC, moderately reduced CFC, minimally reduced CFC or normal flow using previously defined perfusion thresholds. The endpoint was a composite of death and non-fatal myocardial infarction (MI).

Results

The composite endpoint occurred in 153 (12%) patients during a median follow-up of 5.5 (interquartile range 3.7–7.8) years. Myocardial steal (HR 10.65, 95% CI 4.45–25.49, p&lt;0.001), severely reduced CFC (HR 3.77, 95% CI 1.88–7.58, p&lt;0.001), moderately reduced CFC (HR 2.03, 95% CI 1.25–3.29, p=0.004) and minimally reduced CFC (HR 1.72, 95% CI 1.05–2.81, p=0.030) were independently associated with worse outcome after adjusting for clinical risk factors. Similarly, increased resting MBF (HR 3.19, 95% CI 1.74–5.83, p&lt;0.001), decreased hMBF (HR 0.72, 95% CI 0.57–0.90, p=0.004) and decreased CFR (HR 0.59, 95% CI 0.47–0.73, p&lt;0.001) were significant prognostic factors for events. In a combined perfusion model, only resting MBF (p=0.018) and CFC (overall p=0.012) demonstrated independent prognostic value.

Conclusions

[15O]H2O PET-derived resting MBF, hMBF, CFR and CFC were prognostic factors for death and non-fatal MI. Notably, in a combined model including all perfusion metrics, only resting MBF and CFC were independently associated with adverse outcome.

Funding Acknowledgement

Type of funding sources: None.

Exploring macrophage mannose receptor expression after myocardial infarction by Al[18F]F-NOTA-DCM positron emission tomography

Introduction

Mannose receptor (CD206) is primarily expressed on the surface of alternatively activated macrophages that are involved in resolution of inflammation after myocardial injury [1]. The purpose of this study was to evaluate mannose receptor targeting positron emission tomography (PET) tracer Al[18F]F-NOTA-DCM consisting of dextran backbone with cysteine-mannose moieties for imaging of experimental acute myocardial infarction (MI) [2].

Methods

First, ALEXA-488 fluorophore-labelled DCM was used for specificity studies using flow cytometry of M1 and M2 polarized macrophages derived from human blood monocytes. Secondly, Sprague-Dawley rats were studied on day 3 and day 7 after permanent ligation of left coronary artery or after sham-operation. [18F]FDG PET (35 MBq, 10 min static scan) was performed to visualize myocardium and on the next day, 60 min dynamic PET was performed after injection of 50 MBq of Al[18F]F-NOTA-DCM. Then, rats were euthanized for biodistribution study by gamma counting followed by digital autoradiography and histology (H&E, CD206 staining) of left ventricle cryosections. In vitro Al[18F]F-NOTA-DCM blocking study was performed on left ventricle cryosection with molar excess of unlabelled DCM.

Results

Flow cytometry confirmed that ALEXA-488-DCM bound specifically to M2 macrophages. In rats, the infarcted area was clearly detected in vivo with Al[18F]F-NOTA-DCM PET and its SUV was significantly higher than that of remote area or myocardium of sham-operated rats both on day 3 (SUV 0.78±0.18 vs. 0.47±0.13 vs. 0.43±0.07, p&lt;0.005) and day 7 post-MI (SUV 0.64±0.10 vs. 0.47±0.12 vs. 0.51±0.07, p&lt;0.05). Autoradiography confirmed increased uptake in the infarcted area compared to the remote area or to the myocardium of sham-operated rats on day 3 (PSL/mm2 141.21±46.06 vs. 49.76±20.37 vs. 57.97±6.77, p&lt;0.005) and day 7 (PSL/mm2 139.22±19.44 vs. 55.38±28.83 vs. 60.83±7.63, p&lt;0.0001). In vitro blocking study indicated that the tracer binding in infarcted area was specific. The area-% of CD206-positive staining in the infarcted area was significantly higher on day 3 post-MI than on day 7 (p&lt;0.05), and higher at both time points than in remote area or myocardium of sham-operated rats (p&lt;0.0001). Area-% of CD206 staining in the MI area positively correlated with Al[18F]F-NOTA-DCM uptake and MI size (p&lt;0.05 and p&lt;0.01, respectively).

Conclusions

Al[18F]F-NOTA-DCM PET detects overexpression of mannose receptor after ischemic myocardial injury and may be a suitable biomarker for early detection of the inflammation resolution process after MI.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Jane and Aatos Erkko FoundationSigrid Juselius FoundationFInnish Foundation for Cardiovascular Research

Warranty period of normal CCTA and [15O]H2O PET in chest pain patients

Background

Normal coronary computed tomography angiography (CTA) and positron emission tomography (PET) are associated with an excellent prognosis. Hitherto, data on the warranty period of normal coronary CTA and normal myocardial blood flow (MBF) by PET are scarce.

Purpose

To determine the event-free period after normal coronary CTA and PET results. In addition, to determine whether PET MBF imaging confers additional prognostic value beyond coronary anatomy in symptomatic patients.

Methods

Patients with suspected but not previously diagnosed coronary artery disease (CAD) who underwent coronary CTA or [15O]H2O PET were categorized based upon coronary CTA as no CAD, non-obstructive CAD or obstructive CAD. A hyperemic MBF &lt;2.3 ml/min/g was considered abnormal and indicative for ischemia. A cumulative risk below 5% against death and myocardial infarction (MI) was used to define the warranty period.

Results

Of 2575 included patients (mean age 61.4±9.9 years, 41% male) 1319 (51.2%) underwent coronary CTA only, 1237 (48.0%) underwent both coronary CTA and PET and 19 (0.74%) patients underwent PET imaging only. During a median follow-up of 7.0 years 163 deaths and 68 MIs occurred. The warranty period for patients without any CAD was &gt;10 years. Patients with non-obstructive CAD had a 5 year warranty period. In patients with no, non-obstructive or obstructive CAD on CTA, normal PET extended the warranty period with ≥2 years. The warranty period of patients with non-obstructive CAD or normal perfusion varied between 2.5 and &gt;10 years for patients with or without clinical risk factors.

Conclusions

As standalone imaging, the warranty period for a normal coronary CTA is &gt;10 years, whereas patients with non-obstructive CAD have a warranty period of 5 years. Independent of coronary anatomy normal perfusion imaging has additional prognostic value and extends the warranty period by ≥2 years.

Funding Acknowledgement

Type of funding sources: None.

Coronary computed tomography angiography based endothelial wall shear stress in normal coronary arteries

Background

Endothelial wall shear stress (ESS) is a biomechanical force which plays a key role in the formation and evolution of atherosclerotic lesions.

Purpose

This study aims to evaluate ESS in coronary arteries without atherosclerosis, and to assess various factors affecting ESS values.

Methods

Coronary computed tomography angiography (CCTA) images from patients with suspected coronary artery disease were analyzed to identify coronary arteries without atherosclerosis. Minimal and maximal ESS values were calculated for 3-mm segments with dedicated software. Segments were categorized according to lumen diameter tertiles into small (&lt;2.6 mm), intermediate (2.6–3.2 mm) or large (≥3.2 mm) size classes. Normal ranges of minimal and maximal ESS values were calculated per vessel and vessel size.

Results

A total of 349 normal vessels from 168 patients (mean age 59.4±9.2 years, 39% men) were included. ESS was highest in the left anterior descending artery compared to the left circumflex and the right coronary arteries (2.3 Pa vs. 1.9 Pa vs. 1.6 Pa for minimal ESS, p&lt;0.001 and 3.7 Pa vs. 3.0 Pa vs. 2.5 Pa for maximal ESS, p&lt;0.001). ESS values were highest in small vessel segments compared to intermediate or large segments (3.8 Pa vs. 1.7 Pa vs. 1.2 Pa for minimal ESS, p&lt;0.001 and 6.0 Pa vs. 2.6 Pa vs. 2.0 Pa for maximal ESS, p&lt;0.001). Weak to moderate correlation was found between ESS and the distance from the ostium (ρ values ranging from 0.22 to 0.62 for different vessels).

Conclusion

We derived ESS values from the CCTA images for visually normal coronary arteries. ESS values depend strongly on the lumen diameter of the coronary vessel. The normal ranges of minimal and maximal ESS can be used in future studies, where ESS values in stenotic lesions are compared to the normal values derived in the present analysis.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Finnish Foundation for Cardiovascular Research

The use of lipid-lowering medication after diagnostic imaging procedures in patients with chest pain

Background

Coronary CT angiography (CTA) combined with myocardial perfusion imaging accurately detects both non-obstructive and obstructive coronary artery disease (CAD). Lipid-lowering therapy is known to effectively reduce cardiovascular events, but the impact of non-invasive imaging findings on the usage of lipid-lowering therapy remains largely unknown.

Purpose

To assess the use of lipid-lowering medication in patients referred to coronary CTA and subsequent positron emission tomography (PET) myocardial perfusion imaging due to suspected obstructive CAD.

Methods

We retrospectively analyzed data on purchases of lipid-lowering drugs obtained from the Finnish national registry for a time period starting 1 year before and ending 2 years after the date of diagnostic imaging. This time period was divided into six 6-month intervals, for each of which the presence of any statin and/or ezetimibe purchase was recorded. According to the local routine, patients with suspected obstructive (≥50%) stenosis on coronary CTA entered downstream 15O-water PET myocardial perfusion imaging during adenosine stress to assess the hemodynamic significance of the coronary stenosis. The use of medication was compared among patients with normal coronary arteries, non-obstructive CAD, and obstructive CAD.

Results

During 2008–2016, a total of 1973 patients (41% male, median age 63 years) underwent coronary CTA and 33% of these had PET perfusion imaging. There were 9081 purchases of lipid-lowering drugs during the 3-year observation period. There were 676 (34%) patients with normal coronary arteries, 640 (32%) patients with non-obstructive atherosclerosis on CTA, 325 (16%) patients with suspected obstructive stenosis on CTA but normal PET perfusion, and 332 (17%) patients with obstructive stenosis and abnormal hyperemic PET perfusion. The proportion of patients buying lipid-lowering drugs was 24%, 51%, 72%, and 91%, respectively, as assessed within the 6-month interval following the CTA/PET imaging. After diagnostic testing, proportion of patients purchasing lipid-lowering medications increased in all groups except those with normal coronary arteries (Figure 1). However, there was a marked decrease in all patient groups in proportion of patients using lipid-lowering medication towards the end of the 2-year follow-up period.

Conclusions

In a real-world cohort of symptomatic patients with chest pain undergoing diagnostic imaging for suspected CAD, subsequent purchases of lipid-lowering drugs increase in relation to the severity of imaging findings. Although majority of patients with obstructive CAD initially purchased lipid-lowering medication, our results indicate a marked decrease in the use of these preventive medications towards the end of 2-year follow-up period.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): State Research Funding of Turku University Hospital; the Academy of Finland; Finnish Foundation for Cardiovascular Research.

Molecular imaging of alphaVbeta3 integrin for evaluation of myocardial injury after acute myocardial infarction

Background

68Ga-NODAGA-RGD is a positron emission tomography (PET) tracer targeting αvβ3 integrin that is upregulated during angiogenesis. αvβ3 integrin expression increases early after acute myocardial infarction (AMI), and has been proposed as a marker of myocardial repair.

Purpose

We prospectively evaluated the uptake of 68Ga-NODAGA-RGD and its association to left ventricular function after human AMI.

Methods

Thirty patients underwent PET at 7.7±3.8 days after primary percutaneous coronary intervention for ST-elevation AMI. Resting myocardial perfusion was evaluated using 15O-water PET followed by evaluation of 68Ga-NODAGA-RGD uptake 60–75 minutes after injection of 179 MBq of tracer. Left ventricular function was evaluated by transthoracic echocardiography on the day of PET, and at 6-month follow-up. The definition of the ischemic area at risk and remote myocardial segments was based on the culprit coronary arterial segments in invasive angiography. 68Ga-NODAGA-RGD images were co-registered with perfusion images and uptake was measured as the standardized uptake value in the segment with the highest uptake (SUVmax) in ischemic area at risk, and the mean standardized uptake value (SUVmean) in remote segments. In addition, we calculated 68Ga-NODAGA-RGD uptake corrected to the mean myocardial blood flow (MBF) in the area at risk (SUVmax/MBFmean) to account for reduced distribution of tracer in non-viable tissue.

Results

Mean age of patients was 64±9 years, and 90% were males. Uptake of 68Ga-NODAGA-RGD was low in the remote myocardium, but focally increased in the ischemic area at risk (Figure 1). SUVmax in the ischemic area at risk was higher than SUVmean of the remote myocardium (0.73±0.16 vs. 0.51±0.11, p&lt;0.001). 68Ga-NODAGA-RGD SUVmax did not correlate with MBF in the area at risk. Univariable predictors of 68Ga-NODAGA-RGD SUVmax in the area at risk included peak Troponin T (p&lt;0.001), peak pro-BNP (p&lt;0.001), low global longitudinal strain (p=0.01), and low regional longitudinal strain in the area at risk (p=0.02). In multivariable analysis, peak pro-BNP independently predicted SUVmax in the area at risk (p&lt;0.001). At follow-up, left ventricular ejection fraction increased by 1.6±6.9% and global longitudinal strain by 0.5±3.2%. In univariable analysis, SUVmax and SUVmax/MBFmean in the area at risk predicted improvement of global longitudinal strain at 6 months after AMI (p=0.04 and p&lt;0.001, respectively).

Conclusion

68Ga-NODAGA-RGD uptake shows increased αvβ3 integrin expression in the ischemic area at risk early after reperfused AMI that is associated with the extent of myocardial injury, both regional and global systolic dysfunction, and increased left ventricular filling pressure. Increased 68Ga-NODAGA-RGD uptake in ischemic myocardium at risk predicts left ventricular function improvement at 6 months after AMI.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Academy of Finland, Finnish Foundation for Cardiovascular Research

Calcified versus non-calcified plaque volume fraction in patients with coronary artery disease and their association with outcome

Background

The amount of coronary artery calcification is a general marker of coronary atherosclerosis and has been associated with increased risk of adverse cardiac events. On the other hand, calcification of coronary artery plaques has also been considered as a marker of plaque stabilization.

Purpose

We hypothesized that the fraction of the non-calcified volume of the total plaque volume in patients with coronary artery disease (CAD) is associated with abnormal myocardial perfusion and increased risk of future cardiac events.

Methods

Consecutive patients with suspected CAD undergoing sequential coronary computed tomography angiography (CCTA) with selective positron emission tomography (PET) perfusion imaging between 2007 and 2011 were selected. The total, calcified and non-calcified plaque volume (PV) were defined at patient-level. The non-calcified plaque volume fraction was calculated by dividing the non-calcified PV by the total PV, and expressed as percentage. Patients were divided into three groups: patients with 1) non-obstructive CAD (&lt;50% diameter stenosis), 2) suspected coronary stenosis but normal PET perfusion and 3) suspected stenosis and abnormal regional PET perfusion. Difference between high vs. low PV was based on the median value. Clinical outcomes including all-cause mortality and myocardial infarction were recorded for 6.1 [SD 5.3–7.5] years.

Results

In total, 494 patients (age 63±9 years, 55% male) with documented atherosclerosis on CCTA were included. Total PV, calcified PV and non-calcified PV were all significantly larger in patients with abnormal myocardial perfusion compared to patients with non-obstructive CAD (370 [197–739] mm3 vs. 108 [59–177] mm3, 84 [23–220] mm3 vs. 9 [1–34] mm3 and 274 [157–500] mm3 vs. 94 [53–140] mm3, respectively, p&lt;0.001 for all). However, the non-calcified fraction was smaller in patients with reduced myocardial perfusion (75 [63–86]% vs. 89 [76–98]%, p&lt;0.001, Figure 1). During follow-up 35 events occurred. Patients with higher total PV, calcified PV and non-calcified PV showed worse outcome compared to patients with lower PV (log-rank p&lt;0.001, Figure 2). In contrast, patients with a lower non-calcified plaque volume fraction showed poorer outcome (log-rank χ2=5.54; p=0.019) even after adjusting for statin therapy or revascularization.

Conclusion

We observed that higher volumes of any plaque component in general are associated with abnormal perfusion and increased risk of future cardiac events. In contrast, patients with a lower non-calcified plaque volume fraction showed poorer outcome.

Funding Acknowledgement

Type of funding sources: None. Non-calcified plaque volume fractionKaplan-Meier survival analysis

Resting coronary blood flow velocity profile predicts coronary flow reserve in HFpEF

Background

Coronary microvascular disease (CMD) is prevalent in patients with heart failure with preserved ejection fraction (HFpEF). CMD can be assessed by coronary flow reserve (CFR) using transthoracic echocardiography (TTE). We hypothesised that the coronary Doppler flow profile in LAD at rest could reveal information about the downstream resistance in the vessel, where increased resistance is a sign of CMD.

Purpose

We aimed to measure features of the acceleration and deceleration of the LAD Doppler flow profile to investigate association with coronary and cardiac function.

Methods

CFR was assessed in 202 patients by TTE in the PROMIS-HFpEF-study. Detailed flow profile measurements were possible in 169 patients (84%) who constituted the study population. The coronary Doppler flow profiles were analysed with respect to acceleration time (corAT) and slope (corAS) and deceleration pressure half time (corPHT) (figure 1).

Results

The average age was 75±9 years and 55% were female. Atrial fibrillation (AF) was present in 53% and 62% were current or previous smokers. There was no significant difference in gender, age, BMI, blood pressure or heart rate in the CMD vs non-CMD group, but AF as well as a history of smoking was more prevalent in the CMD group, p=0.022 and 0.003 respectively. Further, there were no significant differences in neither corAT nor corAS between the two groups. However, patients with CMD had shorter corPHT of 268±64 ms compared to 298±67 ms, p=0.01. A longer corPHT was associated with increased TAPSE (R=0.205, p=0.007) and higher CFR (R=0.231, p=0.002). In a multivariable analysis adjusted for age, sex, BMI, SBP, reactive hyperemia index, HR, AF, diabetes, CVD, smoking, LVM and study site*, corPHT independently predicted CFR (table 1, p=0.016).

Conclusion

Short pressure half time, indicating a steep deceleration of the coronary Doppler signal at rest, may provide useful information for prediction of CFR determined by transthoracic ultrasound by reflecting the increased resistance in the coronary microvasculature associated with CMD.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Sahlgrenska University Hospital, Sponsor AstraZeneca

Diagnostic performance of advanced cardiac imaging for detection of cardiac sarcoidosis: a systematic review and meta-analysis

Background

Advanced cardiac imaging techniques, 18F-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) and cardiac magnetic resonance (CMR) imaging, have shown high accuracy for the detection of cardiac sarcoidosis (CS) in small studies. This meta-analysis was performed to evaluate the performance of FDG PET and CMR in the diagnosis of CS.

Methods

PubMed, Embase, and Cochrane Library were searched from the earliest available date of indexing to December 2019 for studies evaluating the accuracy of FDG-PET and CMR for the evaluation of possible CS defined mainly by the Japanese Ministry of Health, Labour and Welfare (JMHW) criteria. For robustness, only studies with a sample size of ≥20 patients were selected and sensitivity analysis excluding outliers was conducted. To calculate the overall performance of the diagnostic accuracy of FDG-PET and CMR, summary receiver operating curve (SROC) and area under the curve (AUC) analyses were done. Heterogeneity was evaluated with the Cochrane Q test and I2 test. Possible sources of heterogeneity were further explored by subgroup analyses.

Results

Fourteen studies used FDG-PET and six studies used CMR involving 1491 patients (mean age 53 years, 38% male) fulfilled the inclusion criteria. The pooled sensitivity of FDG-PET for diagnosis of CS was 76.7% (95% CI 71.6–81.2%; Q=4.4, P&lt;0.0001; I2=86.2%) and the pooled specificity was 86.0% (95% CI 82.8–88.8%; Q=37.4, P&lt;0.0001; I2=65.2%). For the CMR, the pooled sensitivity was 94.0% (95% CI 88.8–97.2%; Q=10.59, P=0.06; I2=52.8%) and the pooled specificity was 88.8 (95% CI 85.3–91.3%; Q=80.25, P&lt;0.0001; I2=93.8%). SROC analysis demonstrated good overall accuracy for FDG-PET (AUC value of 0.91, and Q* 0.85) and CMR (AUC value of 0.96, and Q* 0.9) (figure 1). The sensitivity analysis of FDG-PET (11 studies) demonstrated a pooled sensitivity of 86.2% (95% CI 81.3–90.2%; Q=35.3, P=0.0001; I2=71.6%) and pooled specificity of 87.9% (95% CI 84.3–90.9%; Q=16.7, P=0.08; I2=40.2%). Moreover, the sensitivity analysis of CMR (5 studies) showed a pooled sensitivity of 89.3% (95% CI 78.1–96%; Q=7.3, P=0.12; I2=44.9%) and pooled specificity of 77.9% (95% CI 72.1–82.9%; Q=2.5, P=0.6; I2=0%). Meta-regression showed that the age of the patients (coefficient 0.192; P=0.04) and the size of the studies (coefficient 0.035; P=0.028) were the sources of heterogeneity in FDG-PET and CMR, respectively. The subgroup analysis by the age ≥55 years (6 studies and 276 patients) showed improvement in the diagnostic accuracy of FDG-PET with sensitivity of 92.2% (95% CI 86.1–96.2%; Q=18.9, P&lt;0.01; I2=73.5%) and specificity of 85.1% (95% CI 78.4–90.4%; Q=4, P=0.553; I2=0%).

Conclusion

FDG-PET and CMR are useful adjunctive diagnostic tools in the evaluation of CS. Further large multi-center studies are warranted to validate the diagnostic accuracy of FDG-PET and CMR for diagnosis of CS.

Figure 1

Funding Acknowledgement

Type of funding source: None

P314 The functional effects of intramural course of coronary arteries by two-dimensional speckle-tracking dobutamine stress

Background

Intramural course of a coronary artery is a common anatomic variant, especially in the left anterior descending coronary artery (LAD). However, its effect on the myocardial function during stress remains still unclear.

Purpose

We compared regional myocardial strain measured by speckle tracking during dobutamine stress echocardiography (DSE) in patients with or without intramural course of the LAD.

Methods

Fifty patients (63 ±7 years) were prospectively enrolled and underwent DSE, computed tomography angiography (CTA), quantitative 15-Oxygen water positron emission tomographic perfusion imaging (PET), and invasive angiography. Patients with superficial (&gt;1 mm) or deep (&gt;2 mm) intramural course in the LAD were identified using CTA. Regional longitudinal strain and strain rate (LS, LSr), circumferential strain and strain rate (CS, CSr), as well as radial strain and strain rate (RS, RSr) were measured at rest, at a dobutamine dose of 20 mg/kg/min, at peak stress, and at early recovery (1 min after stress). Obstructive coronary artery disease (CAD) was defined as &gt;75% stenosis or 40% to 75% stenosis combined with either fractional flow reserve &lt; 0.80 or ischemia on PET.

Results

Intramural course of the LAD was detected in 17 patients. Of these, 8 patients had obstructive CAD and were excluded. Thus, 9 patients with intramural course and 11 controls without intramural course or obstructive CAD in the LAD were included. Myocardial strain and strain rate in the myocardial territory distal to intramural segment were similar to those in controls at rest, dobutamine stress and early recovery (Figure). Furthermore, there were no significant differences, at all time points, between the regional strain values of the myocardial segments those distal to the superficial and deep intramural course. In the myocardium distal to an intramural coronary segment, regional myocardial flow measured by PET during adenosine stress correlated with the regional LS (r = 0.80, p = 0.004), LSr (r = 0.66, p = 0.03), and CS (r = 0.69, p = 0.02) and RS (r = 0.53, p = 0.07) at the peak dobutamine stress. However, there was no correlation between flow and strain at rest.

Conclusions

Myocardial strain is not consistently affected in patients with intramural course of the LAD during dobutamine stress as assessed by speckle tracking echocardiography. Larger studies are warranted to evaluate whether certain anatomical variants cause abnormalities in systolic myocardial strain.

Abstract P314 Figure.

1032 Evaluation viability in patients with ventricular dysfunction by 2D speckle tracking echocardiography: the impact of low dose dobutamine. A meta-analysis of prospective trials

Background

2D-Speckle tracking echocardiography (2DSTE) has been used for the assessment of myocardial viability in patients with artery disease and left ventricular (LV) dysfunction.

Aim

The purpose of this analysis was to evaluate the diagnostic accuracy of 2DSTE using longitudinal (LS) and rest circumferential strain (CS) in this setting with or without low dose dobutamine (LDD) infusion.

Methods

A systematic review of MEDLINE, Cochrane, and Embase for all the prospective trials using 2DSTE to assess myocardial viability until January 2019 was done. Studies that utilized 2DSTE before coronary revascularisation and used the wall motion evaluation in the long term after the revascularisation as a reference were included. A standard approach of meta-analysis for diagnostic tests and a bivariate analysis of sensitivity, specificity, positive likelihood ratio(+LR), and negative likelihood (-LR) were performed. In addition, direct comparison analysis was done to only studies that compared the tests in the same patients.

Results

A total of 24 studies of 2DSTE evaluating myocardial viability with 1173 patients (mean age 66 years, 72% male, and mean left ventricular ejection fraction was 45%) fulfilled the inclusion criteria. Eight studies used LS, 8 studies used CS, 4 studies used LS with LDD, and 4 studies used CS with LDD. LS and CS with LDD provided higher +LR ( 4.2 and 4, respectively) as well as a best specificity when compared with LS and CS (81% CI: 65- 92% vs 68% CI: 60- 75%, p = 0.04, and 81% CI: 64-91% vs 66% CI: 59-72%, p= 0.02, respectively) for predicting improved segmental LV contractile function after revascularization. The sensitivities of different 2DSTE tests for detection the viability were not statistically different. The direct comparison of the studies with the same patients yielded similar results.

Conclusions

Using LDD with LS and CS analysis significantly improve specificity of the tests. Therefore, the use of a low dose of the dobutamine can be recommended to improve the accuracy of the 2DSTE for detection of viable myocardium following myocardial infarction.

Abstract 1032 Figure. Summary ROC Curves

P6191Proprotein convertase subtilisin/kexin type 9 (PCSK9) plasma levels are associated with the metabolic syndrome in patients with stable coronary artery disease

Background

PCSK9 is a key regulator of serum LDL-cholesterol levels. The relation of PCSK9 with other components of cardiovascular and coronary artery disease (CAD) risk is still debated.

Purpose

To evaluate the association of PCSK9 plasma levels with cardiovascular and coronary risk profile, in patients with symptoms of suspected stable CAD enrolled in the EVINCI study.

Methods

PCSK9 was measured in 522 patients (60.4±8.8 years, 318 males) with symptoms of stable CAD Individual risk was characterized by clinical and bio-humoral variables, including lipid/glucose/inflammatory profiles. Obstructive CAD was firstly ruled-in by multimodality non-invasive imaging and, subsequently, assessed by invasive coronary angiography.

Results

Patients were divided into groups according to PCSK9 quartiles: I (<138 ng/mL), II-III (138–264 ng/mL), and IV (>264 ng/mL) (Table). The prevalence of obstructive CAD at invasive angiography and statin treatment did not differ among groups. Compared with patients in quartile IV, patients in quartile I, had a higher prevalence of metabolic syndrome and higher values of body mass index. Among biomarkers, all cholesterol lipoproteins levels progressively increased from quartile I to IV, while insulin and HOMA index values decreased (Table). At multivariable analyses adjusted for medical treatment, the only clinical or bio-humoral variables independently associated with PCSK9 levels were presence of the metabolic syndrome (Coeff. −0.195, SE 0.05, p<0.0001) and HDL cholesterol levels (Coeff. 0.444, SE 0.06, p<0.0001), respectively.

Table 1 Clinical Variables Quartile I Quartile II–III Quartile IV Biomarkers Quartile I Quartile II–III Quartile IV <138 ng/L 138–264 ng/L >264 ng/L <138 ng/L 138–264 ng/L >264 ng/L (n=130) (n=261) (n=131) (n=130) (n=261) (n=131) Age, years 61±9 60±9 61±8 Glucose, mg/dL 110±30 117±41 109±29 Male gender 86 (66) 161 (62) 71 (55) Insulin, mUI/mL 13.3±12.5* 11.3±10.1 10.3±10.1 Family history 38 (29)# 86 (33) 58 (44) HOMA index 3.9±4.5* 3.5±4.1 2.9±3.3 Hypertension 78 (60) 164 (63) 88 (67) Tryglicerides, mg/dL 128±86 128±87 118±68 Hypercholesterolemia 72 (55) 158 (61) 81 (62) Total cholesterol, mg/dL 171±43* 181±45 203±55 Diabetes mellitus 43 (33) 91 (35) 37 (28) LDL, mg/dL 99±36* 104±38 119±45 Metabolic Syndrome 45 (35)# 72 (28) 19 (15) HDL, mg/dL 46±13* 52±15 61±19 BMI, kg/m2 28.02±4.00* 28.03±4.25 26.95±4.56 Total/HDL cholesterol 3.8±1.2* 3.7±1.2 3.5±1.1 Significant CAD at ICA 18 (14) 46 (18) 24 (18) hs-CRP, mg/dL 0.41±0.61 0.39±1.38 0.41±0.83 Statins treatment 68 (52) 143 (55) 58 (44) Interleukin 6, ng/L 1.60±2.75 1.30±2.49 1.30±1.68 Chi square test: #p<0.05. ANOVA: I vs. IV Quartile: *p<0.05.

Conclusion

In patients with stable CAD, low plasma levels of PCSK9 are associated with the prevalence of metabolic syndrome and its individual components, including, in particular, HDL cholesterol.

Acknowledgement/Funding

AMGEN grant, EU FP7-CP-FP506 2007 project (grant agreement no. 222915)

P1218Deep learning survival analysis enhances the value of hybrid PET/CT for long-term cardiovascular event prediction

Background

Deep Learning (DL) is revolutionizing cardiovascular medicine through complex data-pattern recognition. In spite of its success in the diagnosis of coronary artery disease (CAD), DL implementation for prognostic evaluation of cardiovascular events is still limited. Traditional survival models (e.g.Cox) notably incorporate the effect of time-to-event but are unable to exploit complex non-liner dependencies between large numbers of predictors. On the other hand, DL hasn't systematically incorporated time-to-event for prognostic evaluations. Long-term registries of hybrid PET/CT imaging represent a suitable substrate for DL-based survival analysis due the large amount of time-dependent structured variables that they convey. Therefore, we sought to evaluate the feasibility and performance of DL Survival Analysis in predicting the occurrence of myocardial infarction (MI) and death in a long-term registry of cardiac hybrid PET/CT.

Methods

Data from our PET/CT registry of symptomatic patients with intermediate CAD risk who underwent sequential CT angiography and 15O-water PET for suspected ischemia, was analyzed. The sample has been followed for a 6-year average for MI or death. Ten clinical variables were extracted from electronic records including cardiovascular risk factors, dyspnea and early revascularization. CT angiography images were evaluated segmentally for: presence of plaque, % of luminal stenosis and calcification (58 variables). Absolute stress PET myocardial perfusion data was evaluated globally and regionally across vascular territories (4 variables). Cox-Nnet (a deep survival neural network) was implemented in a 5-fold cross-validated 80:20 split for training and testing. Resulting DL-hazard ratios were operationalized and compared to the observed events developed during follow-up. The performance of Cox-Nnet evaluating structured CT, PET/CT, and PET/CT+clinical variables was compared to expert interpretation (operationalized as: normal coronaries, non-obstructive CAD, obstructive CAD) and to Calcium Score (CaSc), through the concordance (c)-index.

Results

There were 426 men and 525 women with a mean age of 61±9 years-old. Twenty-four MI and 49 deaths occurred during follow-up (1 month–9.6 years), while 11.5% patients underwent early revascularization. Cox-Nnet evaluation of PET/CT data (c-index=0.75) outperformed categorical expert interpretation (c-index=0.54) and CaSc (c-index=0.65), while hybrid PET/CT and PET/CT+clinical (c-index=0.75) variables demonstrated incremental performance overall independent from early revascularization.

Conclusion

Deep Learning Survival Analysis is feasible in the evaluation of cardiovascular prognostic data. It might enhance the value of cardiac hybrid PET/CT imaging data for predicting the long-term development of myocardial infarction and death. Further research into the implementation of Deep Learning for prognostic analyses in CAD is warranted.

P3726Percutaneous left atrial appendage closure and conservative antithrombotic treatment in patients with atrial fibrillation and contraindication to oral anticoagulation: a 5-year follow-up study

Background

Patients with atrial fibrillation (AF) having high thromboembolic risk and either a history of major bleeding or very high bleeding risk form a treatment challenge. Percutaneous left atrial appendage closure (LAAC) offers a feasible option for stroke prevention in these patients. However, the optimal treatment strategy for AF patients with contraindications to oral anticoagulation (OAC) remains unclear.

Purpose

To study periprocedural and late events after LAAC in AF patients with contraindications to OAC therapy.

Methods

Data were collected into a prospective registry from all consenting AF patients who underwent LAAC from February 2009 to August 2018. Follow-up data was gathered during scheduled clinical visits, annual phone calls and by reviewing electronic patient records. Only AF patients with contraindications to OAC were considered for the present analysis.

Results

LAAC using mainly Amplatzer Cardiac Plugs (98.2%) was attempted in a total of 172 patients (mean age 74 years; 60 women). The mean CHA2DS2-VASc score was 3.8±1.5 and HAS-BLED score 4.0±1.0. Contraindications to OAC were prior intracranial bleeding in 112 (65.1%), other major bleeding in 33 (19.2%) and high bleeding risk in 27 patients (15.7%). Procedure was technically successful in 166 (96.5%) patients. Clinically significant in-hospital complications were as follows: two patients (1.2%) had cardiac tamponade, which was fatal in one case, one (0.6%) had device embolization and eight (4.7%) had major access site-related bleeding events. None of the patients had in-hospital thromboembolic complications. After successful implantation, 152 patients (91.6%) were discharged on aspirin. Single antiplatelet therapy was more common than dual or triple antiplatelet therapy (74.7% vs. 18.1% vs. 1.8%, respectively), while 8 patients (4.8%) received no antiplatelet therapy. The length of initial antiplatelet therapy ranged from 0.5 to 12 months and long-term antiplatelet therapy was prescribed in 53 patients (31.9%). After a median follow-up of 33 months (interquartile range 12–49) there were 29 deaths (17.5%), 16 thromboembolic events (9.6%), consisting of 11 strokes (6.6%) and 5 transient ischemic attacks (3.0%). At the time of thromboembolic event, 10 patients (62.5%) were on antithrombotic therapy. Eighteen patients (10.8%) had at least one major bleeding event after the index hospitalization. Intracranial bleeding occurred in 7 patients (4.2%) and 6 of them (85.7%) were on antithrombotic therapy when the event occurred. Most thromboembolic events (68.8%) and intracranial bleedings (57.1%) occurred after one year of follow-up. One patient (0.6%) had an asymptomatic device embolization detected at 3-month control visit. No predictive factors for thromboembolic or major bleeding events were identified.

Conclusion

The early outcome of this challenging patient group is good after LAAC, but thromboembolic and major bleeding events are not uncommon during later follow-up.

Validation of [18F]fluorodeoxyglucose and positron emission tomography (PET) for the measurement of intestinal metabolism in pigs, and evidence of intestinal insulin resistance in patients with morbid obesity

AIMS/HYPOTHESIS

The role of the intestine in the pathogenesis of metabolic diseases is gaining much attention. We therefore sought to validate, using an animal model, the use of positron emission tomography (PET) in the estimation of intestinal glucose uptake (GU), and thereafter to test whether intestinal insulin-stimulated GU is altered in morbidly obese compared with healthy human participants.

METHODS

In the validation study, pigs were imaged using [(18)F]fluorodeoxyglucose ([(18)F]FDG) and the image-derived data were compared with corresponding ex vivo measurements in tissue samples and with arterial-venous differences in glucose and [(18)F]FDG levels. In the clinical study, GU was measured in different regions of the intestine in lean (n = 8) and morbidly obese (n = 8) humans at baseline and during euglycaemic hyperinsulinaemia.

RESULTS

PET- and ex vivo-derived intestinal values were strongly correlated and most of the fluorine-18-derived radioactivity was accumulated in the mucosal layer of the gut wall. In the gut wall of pigs, insulin promoted GU as determined by PET, the arterial-venous balance or autoradiography. In lean human participants, insulin increased GU from the circulation in the duodenum (from 1.3 ± 0.6 to 3.1 ± 1.1 μmol [100 g](-1) min(-1), p < 0.05) and in the jejunum (from 1.1 ± 0.7 to 3.0 ± 1.5 μmol [100 g](-1) min(-1), p < 0.05). Obese participants failed to show any increase in insulin-stimulated GU compared with fasting values (NS).

CONCLUSIONS/INTERPRETATION

Intestinal GU can be quantified in vivo by [(18)F]FDG PET. Intestinal insulin resistance occurs in obesity before the deterioration of systemic glucose tolerance.