Noninvasive transthoracic doppler flow velocity and invasive thermodilution to assess coronary flow reserve

Background

Coronary flow reserve (CFR) provides prognostication and coronary physiological information, including epicardial coronary stenosis and microvascular function. The relationship between stress transthoracic Doppler echocardiography (TDE)-derived coronary flow velocity reserve (CFRS-TDE) and thermodilution-derived coronary flow reserve (CFRthermo) before and after elective percutaneous coronary intervention (PCI) remains unclear.

Methods

This single-center prospective registry study evaluated patients who underwent fractional flow reserve (FFR)-guided elective PCI for left anterior descending artery (LAD) lesions with wire-based invasive physiological measurements and pre- and post-PCI stress TDE examinations.

Results

A total of 174 LAD lesions from 174 patients were included in the final analysis. A modest correlation was detected between the pre-PCI CFRS-TDE and the pre-PCI CFRthermo (r=0.383, P<0.001). The frequently used CFRS-TDE threshold of 2.0 corresponded to a pre-PCI CFRthermo of 2.18. Pre-PCI CFRS-TDE underestimated pre-PCI CFRthermo [1.89 (1.44-2.31) vs. 2.05 (1.38-2.93), P<0.001]. Both CFRS-TDE and CFRthermo increased significantly post-PCI [pre-PCI CFRS-TDE 1.89 vs. post-PCI CFRS-TDE 2.33, P<0.001; pre-PCI CFRthermo 2.05 (1.38-2.93) vs. post-PCI CFRthermo 2.59 (1.63-3.55), P<0.001]. In contrast, there was no significant relationship between changes in CFRS-TDE and changes in CFRthermo after PCI (r=0.008, P=0.915) or between post-PCI CFRS-TDE and post-PCI CFRthermo (r=0.054, P=0.482).

Conclusions

Pre-PCI CFRS-TDE and CFRthermo are modestly correlated, but post-PCI CFRS-TDE and CFRthermo have no correlation. CFRS-TDE and CFRthermo are not interchangeable, particularly post-PCI, suggesting that the two metrics represent different coronary physiologies after PCI.

Effect of quantitative parameters of contrast-enhanced ultrasound on the long-term prognosis of patients with chronic coronary syndrome

Background

Ultrasound is one of the most commonly used examination methods in patients with coronary artery disease (CAD) and is valuable in evaluating patient prognosis. Although contrast-enhanced ultrasound (CEUS) can assess more in depth the vascular lesions of patients, there is still a lack of relevant research on the value of quantitative parameters of CEUS in predicting the long-term prognosis of patients with chronic coronary syndrome (CCS), thus, we designed this study.

Methods

From January 2016 to December 2017, a total of 473 patients with CCS admitted to Yueyang People's Hospital were retrospectively enrolled. The patients were followed up for five years. According to whether the patients had major adverse cardiovascular events (MACE), patients were divided into the MACE group (n=113) and the control group (n=360). The CEUS was performed to detect the myocardial perfusion status. The value of quantitative parameters of CEUS in predicting the MACE in patients with CCS was analyzed using the receiver operating characteristic (ROC) curve.

Results

Peak intensity of contrast agent at platform stage, rising rate of microbubble reperfusion, and left ventricular ejection fraction (LVEF) were found to be valuable in predicting the risk of MACE in patients with CCS. Among them, the peak intensity of contrast agent at platform stage had the highest predictive value, and the area under the curve (AUC) was 0.860 [95% confidence interval (CI): 0.827-0.894, P<0.001]. Multivariate logistics regression analysis showed that the peak intensity of contrast agent at platform stage <4.54 dB and rising rate of microbubble reperfusion <0.275 s were independent risk factors of MACE in patients with CCS. The relative risks were 12.238 (95% CI: 6.632-22.585) and 5.724 (95% CI: 3.149-10.405), respectively.

Conclusions

Quantitative parameters of CEUS can be used as predictors of MACE in patients with CCS, and strengthening the management of such high-risk patients may be beneficial to reduce the incidence of MACE.

Diagnostic value of computed tomography myocardial perfusion imaging to detect coexisting microvascular dysfunction in patients with obstructive epicardial coronary artery disease

Background

Computed tomography myocardial perfusion (CT-MP) has reported usefulness in assessing hemodynamically significant epicardial coronary artery lesions. However, the diagnostic ability of the absolute coronary flow using CT-MP to detect coronary microvascular dysfunction (CMD) remains elusive. This prospective cohort study aimed to assess the diagnostic value of CT-MP in evaluating coexisting CMD in patients with functionally significant epicardial coronary stenosis and to analyze the predictive factors of lesions with CMD.

Methods

Sixty-eight patients with chronic coronary syndrome (CCS) and de novo single functionally significant stenosis [fractional flow reserve (FFR) ≤0.80] were studied. CMD was defined as an index of microcirculatory resistance ≥25. We compare clinical background and CT-MP findings between patients with and without CMD (CMD, n=29; non-CMD, n=39). CT-MP, and quantitative and qualitative plaque assessments were included in computed tomography angiography assessment. Logistic regression analysis was performed to predict CMD.

Results

FFR, invasive wire-derived coronary flow reserve (CFRwire) and index of microcirculatory resistance were 0.68 [interquartile range (IQR), 0.59-0.74], 1.71 (IQR, 1.24-2.88), and 22.6 (IQR, 15.1-34.5), respectively. The rest and hyperemic-myocardial blood flow (MBF) and CT-MP-derived CFR (CFRCT-MP) were 0.83 (0.64-1.03) mL/min/g, 2.14 (1.30-2.92) mL/min/g, and 2.19 (1.44-3.37), respectively. In the territories with CMD, hyperemic-MBF was significantly lower than in those without [1.68 (IQR, 0.84-2.44) vs. 2.31 (IQR, 1.67-3.34) mL/min/g, P=0.015] and the prevalence of CFRCT-MP <2.0 was higher in the lesions with CMD than in those without (62.1% vs. 28.2%, P=0.011), while FFR values were similar. Fibrofatty and necrotic core component volume was greater in the vessels with CMD than in those without [31.8 (IQR, 19.0-48.9) vs. 25.1 (IQR, 17.2-32.1) mm3, P=0.045]. Multivariable logistic regression analysis showed that hyperemic-MBF and fibrofatty and necrotic core component volume were independent predictors of CMD territories [odds ratio (OR) =0.583; 95% confidence interval (CI): 0.355-0.958; P=0.033 and OR =1.040; 95% CI: 1.010-1.070; P=0.011].

Conclusions

Quantitative assessment of absolute coronary flow using pre-percutaneous coronary intervention (PCI) CT-MP, and comprehensive plaque analysis using computed tomography angiography may help detect coexisting subtended microvascular dysfunction in territories with functionally significant epicardial coronary lesions. Further studies are required to elucidate the clinical significance of coexisting CMD in patients with CCS undergoing PCI.

Angiography-based index of microcirculatory resistance (AccuIMR) for the assessment of microvascular dysfunction in acute coronary syndrome and chronic coronary syndrome

Background

To assess the diagnostic accuracy of AccuIMR, a newly proposed, pressure wire-free index, in identifying coronary microvascular dysfunction (CMD) among patients with acute coronary syndrome [including ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI)] and chronic coronary syndrome (CCS).

Methods

A total of 163 consecutive patients (43 with STEMI, 59 with NSTEMI, and 61 with CCS), who underwent invasive coronary angiography (ICA) and for whom the index of microcirculatory resistance (IMR) was measured, were retrospectively enrolled at a single center. IMR measurements were made in 232 vessels. The AccuIMR based on computational fluid dynamics (CFD) was calculated from coronary angiography. The diagnostic performance of AccuIMR was assessed using wire-based IMR as a reference standard.

Results

AccuIMR correlated well with IMR (overall r=0.76, P<0.001; STEMI r=0.78, P<0.001; NSTEMI r=0.78, P<0.001; CCS r=0.75, P<0.001) and had good diagnostic performance in detecting abnormal IMR [overall diagnostic accuracy, sensitivity, and specificity were 94.83% (91.14% to 97.30%), 92.11% (78.62% to 98.34%), and 95.36% (91.38% to 97.86%), respectively]. Using a cutoff value of IMR >40 U for AccuIMR in STEMI and IMR >25 U in NSTEMI and CCS, the area under the receiver operating characteristic (ROC) curve (AUC) of AccuIMR for predicting abnormal IMR value was 0.917 (0.874 to 0.949) in all patients, 1.000 (0.937 to 1.000) in patients with STEMI, 0.941 (0.867 to 0.980) in patients with NSTEMI, and 0.918 (0.841 to 0.966) in patients with CCS.

Conclusions

The use of AccuIMR in the evaluation of microvascular diseases could provide valuable information and potentially increase the application of physiological assessment for microcirculation in patients with ischemic heart disease.

Efficacy and safety outcomes of long-term anti-thrombotic treatment of chronic coronary artery disease: A systematic review and network meta-analysis

Background

Clopidogrel, prasugrel, ticagrelor, and low-dose rivaroxaban are all optional strategies in conjunction with aspirin for long-term treatment of chronic coronary artery disease. The aim of this research was to assess the efficacy and safety of long-term anti-thrombotic treatment of chronic coronary heart disease.

Methods

PubMed (MEDLINE), Embase, Clinical Trials Registry ClinicalTrials.gov, and The Cochrane Library were searched through November 2021, to identify randomized controlled trials that compared long term anti-thrombotic therapy for coronary heart disease. Data were extracted to assess eligibility by two independent reviewers. Random-effects meta-analysis was used to pool results.

Results

Eleven randomized controlled trials were included (88,462 patients). In a network meta-analysis, the rivaroxaban compared to the clopidogrel regimen showed lower relative risks (RRs) for death of any cause (0.71; 95% confidence interval [CI], 0.52-0.96), major adverse cardiac events (MACE) (0.73; 95% CI, 0.57-0.93), and cerebrovascular events (0.48; 95% CI, 0.30-0.78). The RR of cerebrovascular events was also lower for the rivaroxaban compared to the ticagrelor 60 mg regimen (0.72; 95% CI, 0.52-0.99). For the prasugrel regimen, the RRs were lower of myocardial infarction incidence versus all extended strategies: clopidogrel plus aspirin (0.76; 95% CI, 0.58-0.99), rivaroxaban (0.60; 95% CI, 0.38-0.93), ticagrelor 60 mg (0.61; 95% CI, 0.42-0.89), and ticagrelor 90 mg (0.63; 95% CI, 0.41-0.97). None of the dual strategies were associated with differences in major bleeding compared to the prasugrel regimen.

Conclusions and relevance

The rivaroxaban regimen appeared to be the preferred long-term anti-thrombotic regimen in preventing all-cause mortality. Our available results tend to support the efficacy of extended anti-thrombotic therapy consisting of prasugrel in lowering MI incidence compared to the other strategies, without increased risk of bleeding. However, additional large-scale direct clinical trials are needed to further determine the adequate long-term anti-thrombotic regimens for treating chronic coronary syndrome.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020186583, identifier CRD42020186583.

The challenges of a randomised placebo-controlled trial of CTO PCI vs. placebo with optimal medical therapy: The ORBITA-CTO pilot study design and protocol

Background

Percutaneous coronary intervention (PCI) for coronary chronic total occlusion (CTO) has been performed for the improvement of symptoms and quality of life in patients with stable angina. The ORBITA study demonstrated the role of the placebo effect in contemporary PCI in non-CTO chronic coronary syndromes. However, the benefit of CTO PCI beyond that of a placebo has not been demonstrated.

Aims

The ORBITA-CTO pilot study will be a double-blind, placebo-controlled study of CTO PCI randomising patients who have: (1) been accepted by a CTO operator for PCI; (2) experienced symptoms due to a CTO; (3) evidence of ischaemia; (4) evidence of viability within the CTO territory; and (5) a J-CTO score ≤3.

Methods

Patients will undergo medication optimisation that will ensure they are on at least a minimum amount of anti-anginals and complete questionnaires. Patients will record their symptoms on an app daily throughout the study. Patients will undergo randomisation procedures, including an overnight stay, and be discharged the following day. All anti-anginals will be stopped after randomisation and re-initiated on a patient-led basis during the 6-month follow-up period. At follow-up, patients will undergo repeat questionnaires and unblinding, with a further 2-week unblinded follow-up.

Results

The co-primary outcomes are feasibility (blinding) in this cohort and angina symptom score using an ordinal clinical outcome scale for angina. Secondary outcomes include changes in quality-of-life measures, Seattle Angina Questionnaire (SAQ), peak VO2, and anaerobic threshold on the cardiopulmonary exercise test.

Conclusion

The feasibility of a placebo-controlled CTO PCI study will lead to future studies assessing efficacy. The impact of CTO PCI on angina measured using a novel daily symptom app may provide improved fidelity in assessing symptoms in patients with CTO's.

Determinants of Non-calcified Low-Attenuation Coronary Plaque Burden in Patients Without Known Coronary Artery Disease: A Coronary CT Angiography Study

Background

Although epicardial adipose tissue (EAT) is associated with coronary artery disease (CAD), it is unclear whether EAT volume (EAV) can be used to diagnose high-risk coronary plaque burden associated with coronary events. This study aimed to investigate (1) the prognostic impact of low-attenuation non-calcified coronary plaque (LAP) burden on patient level analysis, and (2) the association of EAV with LAP volume in patients without known CAD undergoing coronary computed tomography angiography (CCTA).

Materials and Methods

This retrospective study consisted of 376 patients (male, 57%; mean age, 65.2 ± 13 years) without known CAD undergoing CCTA. Percent LAP volume (%LAP, <30 HU) was calculated as the LAP volume divided by the vessel volume. EAT was defined as adipose tissue with a CT attenuation value ranging from −250 to −30 HU within the pericardial sac. The primary endpoint was a composite event of death, non-fatal myocardial infarction, and unstable angina and worsening symptoms requiring unplanned coronary revascularization >3 months after CCTA. The determinants of %LAP (Q4) were analyzed using a multivariable logistic regression model.

Results

During the follow-up period (mean, 2.2 ± 0.9 years), the primary endpoint was observed in 17 patients (4.5%). The independent predictors of the primary endpoint were %LAP (Q4) (hazard ratio [HR], 3.05; 95% confidence interval [CI], 1.09–8.54; p = 0.033] in the Cox proportional hazard model adjusted by CAD-RADS category. Cox proportional hazard ratio analysis demonstrated that %LAP (Q4) was a predictor of the primary endpoint, independnet of CAD severity, Suita score, EAV, or CACS. The independent determinants of %LAP (Q4) were CACS ≥218.3 (p < 0.0001) and EAV ≥125.3 ml (p < 0.0001). The addition of EAV to CACS significantly improved the area under the curve (AUC) to identify %LAP (Q4) than CACS alone (AUC, EAV + CACS vs. CACS alone: 0.728 vs. 0.637; p = 0.013).

Conclusions

CCTA-based assessment of EAV, CACS, and LAP could help improve personalized cardiac risk management by administering patient-suited therapy.

Correlation Between Plasma Proteomics and Adverse Outcomes Among Older Men With Chronic Coronary Syndrome

Background

Chronic coronary syndrome (CCS) is a newly proposed concept and is hallmarked by more long-term major adverse cardiovascular events (MACEs), calling for accurate prognostic biomarkers for initial risk stratification.

Methods

Data-independent acquisition liquid chromatography tandem mass spectrometry (DIA LC-MS/MS) quantitative proteomics was performed on 38 patients with CCS; 19 in the CCS events group and 19 in the non-events group as the controls. We also developed a machine-learning-based pipeline to identify proteins as potential biomarkers and validated the target proteins by enzyme-linked immunosorbent assay in an independent prospective cohort.

Results

Fifty-seven differentially expressed proteins were identified by quantitative proteomics and three final biomarkers were preliminarily selected from the machine-learning-based pipeline. Further validation with the prospective cohort showed that endothelial protein C receptor (EPCR) and cholesteryl ester transfer protein (CETP) levels at admission were significantly higher in the CCS events group than they were in the non-events group, whereas the carboxypeptidase B2 (CPB2) level was similar in the two groups. In the Cox survival analysis, EPCR and CETP were independent risk factors for MACEs. We constructed a new prognostic model by combining the Framingham coronary heart disease (CHD) risk model with EPCR and CETP levels. This new model significantly improved the C-statistics for MACE prediction compared with that of the Framingham CHD risk model alone.

Conclusion

Plasma proteomics was used to find biomarkers of predicting MACEs in patients with CCS. EPCR and CETP were identified as promising prognostic biomarkers for CCS.

Extracellular Vesicles in Diagnosing Chronic Coronary Syndromes the Bumpy Road to Clinical Implementation

Coronary artery disease (CAD), comprising both acute coronary syndromes (ACS) and chronic coronary syndromes (CCS), remains one of the most important killers throughout the entire world. ACS is often quickly diagnosed by either deviation on an electrocardiogram or elevated levels of troponin, but CCS appears to be more complicated. The most used noninvasive strategies to diagnose CCS are coronary computed tomography and perfusion imaging. Although both show reasonable accuracy (80–90%), these modalities are becoming more and more subject of debate due to costs, radiation and increasing inappropriate use in low-risk patients. A reliable, blood-based biomarker is not available for CCS but would be of great clinical importance. Extracellular vesicles (EVs) are lipid-bilayer membrane vesicles containing bioactive contents e.g., proteins, lipids and nucleic acids. EVs are often referred to as the “liquid biopsy” since their contents reflect changes in the condition of the cell they originate from. Although EVs are studied extensively for their role as biomarkers in the cardiovascular field during the last decade, they are still not incorporated into clinical practice in this field. This review provides an overview on EV biomarkers in CCS and discusses the clinical and technological aspects important for successful clinical application of EVs.