Value Of Reserve Research Articles

The impact of primary percutaneous coronary intervention strategies during st-elevation myocardial infarction on the prevalence of coronary microvascular dysfunction

Abstract Introduction Up to 20% of ST-elevation myocardial infarction (STEMI) patients who undergo primary percutaneous coronary intervention (PCI) continue to have persistent angina, which is considered to be a significant side effect of reperfusion therapy and is associated with coronary microvascular dysfunction (CMD). Purpose To determine if there is a correlation between the technique employed in primary PCI in STEMI patients and the prevalence of CMD after reperfusion. Methods This is a prospective single-blinded observational cohort study conducted in a tertiary cardiac care center in the republic of Lithuania. The study enrolled STEMI patients with multivessel coronary artery disease who underwent primary PCI. Three months later, participants underwent staged PCI of their non-culprit vessels and evaluation for CMD. CMD was defined as an index of microcirculatory resistance (IMR) value ≥ 25 U and a coronary flow reserve (CFR) value < 2.5 U. PCI technique, such as direct stenting or conventional stenting (balloon angioplasty followed by stenting), aspiration thrombectomy, and intracoronary glycoprotein IIb/IIIa inhibitor administration, were prospectively documented. We tested for overall differences in patient characteristics and outcomes between groups using Chi-Square (or Kruskal-Wallis) tests and used the Holm-Bonferroni adjustment (or Dunn's tests) for subsequent pairwise tests. We also performed logistic regression. Results 200 patients were enrolled, with 96 (48%) and 104 (52%), respectively, undergoing direct and conventional stenting. The median age was 65.5 [58, 76] years, most patients were men (59.5%) and 46 patients (23%) met criteria for CMD. Baseline characteristics and risk factors were similar between those with and without CMD. Patients who underwent direct stenting were less likely to suffer from CMD compared to those who underwent conventional stenting (10 (10.4%) vs 36 (34.6%); p < 0.001). In the logistic multivariable analysis, direct stenting, aspiration thrombectomy, and administrations of glycoprotein IIb/IIIa had a ROC AUC of 0.765, indicating good predictive ability. In this particular model, direct stenting, aspiration thrombectomy, and the administration of an intracoronary glycoprotein IIb/IIIa inhibitor were associated with decreased odds of the presence of CMD (OR: 0.193, 95% CI: 0.087-0.430, p < 0.001), (OR: 0.243, 95% CI: 0.086-0.688, p = 0.008), and (OR: 0.200, 95% CI: 0.065-0.620, p = 0.005), respectively. Conclusion In STEMI patients undergoing primary PCI, direct stenting is associated with reduced prevalence of CMD compared with conventional stenting. Furthermore, performing aspiration thrombectomy and administering a glycoprotein IIb/IIIa inhibitor was also associated with a lower prevalence of CMD.Forest plot for the outcome of CMDROC for the model of CMD

Primary versus iatrogenic (post-PCI) coronary microvascular dysfunction: a wire-based multimodal comparison

BackgroundAlthough there are studies examining each one separately, there are no data in the literature comparing the magnitudes of the iatrogenic, percutaneous coronary intervention (PCI)-induced, microvascular dysfunction (Type-4 CMD) and...

Deferred vs. Performed Percutaneous Coronary Intervention for Coronary Stenosis with Grey-Zone Fractional Flow Reserve Values

Deferred vs. Performed Percutaneous Coronary Intervention for Coronary Stenosis with Grey-Zone Fractional Flow Reserve Values

Fractional Flow Reserve-Based Patient Risk Classification.

Cardiovascular diseases (CVDs) are a leading cause of death. If not treated in a timely manner, cardiovascular diseases can cause a plethora of major life complications that can include disability and a loss of the ability to work. Globally, acute myocardial infarction (AMI) is responsible for about 3 million deaths a year. The development of strategies for prevention, but also the early detection of cardiovascular risks, is of great importance. The fractional flow reserve (FFR) is a measurement used for an assessment of the severity of coronary artery stenosis. The goal of this research was to develop a technique that can be used for patient fractional flow reserve evaluation, as well as for the assessment of the risk of death via gathered demographic and clinical data. A classification ensemble model was built using the random forest machine learning algorithm for the purposes of risk prediction. Referent patient classes were identified by the observed fractional flow reserve value, where patients with an FFR higher than 0.8 were viewed as low risk, while those with an FFR lower than 0.8 were identified as high risk. The final classification ensemble achieved a 76.21% value of estimated prediction accuracy, thus achieving a mean prediction accuracy of 74.1%, 77.3%, 78.1% and 83.6% over the models tested with 5%, 10%, 15% and 20% of the test samples, respectively. Along with the machine learning approach, a numerical approach was implemented through a 3D reconstruction of the coronary arteries for the purposes of stenosis monitoring. Even with a small number of available data points, the proposed methodology achieved satisfying results. However, these results can be improved in the future through the introduction of additional data, which will, in turn, allow for the utilization of different machine learning algorithms.

Effects of Fractional Flow Reserve on Coronary Artery Bypass Graft Flow to Left Anterior Descending Artery.

The relationships between preoperative fractional flow reserve (FFR) values of the left anterior descending artery (LAD), FFRLAD, and intraoperative transit time flow measurement (TTFM) variables in coronary artery bypass grafting (CABG) remain unclear.Methods and Results: We retrospectively collected data for 74 in situ left internal thoracic artery (LITA) grafts and 27 saphenous vein grafts (SVGs) to the LAD that were shown to be patent on postoperative angiography. Spearman correlation coefficients were determined between FFRLADand TTFM parameters of the LITA graft, as follows: maximum flow (Qmax), -0.22 (P=0.077); minimum flow (Qmin), -0.40 (P=0.014); mean flow (Qm), -0.35 (P=0.039); pulsatility index (PI), 0.33 (P=0.008); diastolic filling (DF): 0.01 (P=0.83); and systolic reverse flow (SRF), 0.37 (P=0.002). Spearman correlation coefficients between FFRLADand TTFM parameters of the SVG to LAD were: Qmax, -0.65 (P=0.004); Qmin, -0.43 (P=0.044); Qm, -0.75 (P=0.001); PI, 0.53 (P=0.033); DF, 0.14 (P=0.48); and SRF, 0.61 (P=0.009). Both LITA grafts and SVGs to the LAD show negative correlations for FFRLADwith Qminand Qm, but positive correlations for FFRLADwith PI and SFR. These relationships between FFRLADand TTFM variables of CABG grafts to the LAD should be recognized.

Coronary Physiology Guidance vs Conventional Angiography for Optimization of Percutaneous Coronary Intervention: The AQVA-II Trial

BackgroundThe debate surrounding the efficacy of coronary physiological guidance compared with conventional angiography in achieving optimal post–percutaneous coronary intervention (PCI) fractional flow reserve (FFR) values persists. ObjectivesThe primary aim of this study was to demonstrate the superiority of physiology-guided PCI, using either angiography or microcatheter-derived FFR, over conventional angiography-based PCI in complex high-risk indicated procedures (CHIPs). The secondary aim was to establish the noninferiority of angiography-derived FFR guidance compared with microcatheter-derived FFR guidance. MethodsPatients with obstructive coronary lesions and meeting CHIP criteria were randomized 2:1 to receive undergo physiology- or angiography-based PCI. Those assigned to the former were randomly allocated to angiography- or microcatheter-derived FFR guidance. CHIP criteria were long lesion (>28 mm), tandem lesions, severe calcifications, severe tortuosity, true bifurcation, in-stent restenosis, and left main stem disease. The primary outcome was invasive post-PCI FFR value. The optimal post-PCI FFR value was defined as >0.86. ResultsA total of 305 patients (331 study vessels) were enrolled in the study (101 undergoing conventional angiography-based PCI and 204 physiology-based PCI). Optimal post-PCI FFR values were more frequent in the physiology-based PCI group compared with the conventional angiography-based PCI group (77% vs 54%; absolute difference 23%, relative difference 30%; P < 0.0001). The occurrence of the primary outcome did not differ between the 2 physiology-based PCI subgroups, demonstrating the noninferiority of angiography- vs microcatheter-derived FFR (P < 0.01). ConclusionsIn CHIP patients, procedural planning and guidance on the basis of physiology (through either angiography- or microcatheter-derived FFR) are superior to conventional angiography for achieving optimal post-PCI FFR values. (Physiology Optimized Versus Angio-Guided PCI [AQVA-II]; NCT05658952)

Performance of a novel artificial intelligence software developed to derive coronary fractional flow reserve values from diagnostic angiograms.

Although invasive measurement of fractional flow reserve (FFR) is recommended to guide revascularization, its routine use is underutilized. Recently, a novel non-invasive software that can instantaneously produce FFR values from the diagnostic angiograms, derived completely from artificial intelligence (AI) algorithms has been developed. We aim to assess the accuracy and diagnostic performance of AI-FFR in a real-world retrospective study. Retrospective, three-center study comparing AI-FFR values with invasive pressure wire-derived FFR obtained in patients undergoing routine diagnostic angiography. The accuracy, sensitivity, and specificity of AI-FFR were analyzed. A total of 304 vessels from 297 patients were included. Mean invasive FFR was 0.86 vs. 0.85 AI-FFR (mean difference: -0.005, P = 0.159). The diagnostic performance of AI-FFR demonstrated sensitivity of 91%, specificity 95%, positive predictive value 83% and negative predictive value 97%. Overall accuracy was 94% and the area under curve was 0.93 (95% CI 0.88-0.97). 105 lesions fell around the cutoff value (FFR = 0.75-0.85); in this sub-group, AI-FFR demonstrated sensitivity of 95%, and specificity 94%, with an AUC of 0.94 (95% CI 88.2-98.0). AI-FFR calculation time was 37.5 ± 7.4 s for each angiographic video. In 89% of cases, the software located the target lesion and in 11%, the operator manually marked the target lesion. AI-FFR calculated by an AI-based, angio-derived method, demonstrated excellent diagnostic performance against invasive FFR. AI-FFR calculation was fast with high reproducibility.

Dynamic perfusion SPECT for functional evaluation in symptomatic patients with myocardial bridging

BackgroundThe aim of this study was to investigate the feasibility and diagnostic value of myocardial flow reserve (MFR) assessed by rest/stress myocardial perfusion imaging with dynamic single-photon emission computed tomography (SPECT) in the functional evaluation of myocardial bridge (MB). MethodsFrom May 2017 to July 2021, patients with angiographically confirmed isolated MB on the left anterior descending artery (LAD) who underwent dynamic SPECT myocardial perfusion imaging were retrospectively included. The assessment of semiquantitative indices of myocardial perfusion (summed stress scores, SSS) and quantitative parameters (MFR) was performed. ResultsA total of 49 patients were enrolled. The mean age of the subjects was 61.0 ± 9.0 years. All of the patients were symptomatic, and 16 cases (32.7%) presented with typical angina. SPECT-derived MFR showed a borderline significantly negative correlation with SSS (r = 0.261, P = .070). There was a trend of higher prevalence of impaired myocardial perfusion defined as MFR < 2 than as SSS ≥ 4 (42.9% vs 26.5%; P = .090). ConclusionOur data support that SPECT MFR may be a useful parameter for the functional assessment of MB. In patients with MB, the use of dynamic SPECT could be a potential method for hemodynamic assessment.

Energy loss is related to CT fractional flow reserve progression in type 2 diabetes mellitus patients

BackgroundWe aimed to investigate the diagnostic value of energy loss (EL) and baseline CT fractional flow reserve (CT-FFR) computed using computational fluid dynamics to predict functional progression of coronary stenosis in patients with type 2 diabetes mellitus. MethodsThis single-center prospective study included 61 patients with type 2 diabetes mellitus (mean age, 61 years ±9 [SD]; 43 men) showing 20–70 % stenosis who underwent serial coronary CT performed at 2-year interval between October 2015 and March 2020. A mesh-free simulation was performed to calculate the CT-FFR and EL. Functional progression was defined as ≥ 0.05 decrease in CT-FFR on the second coronary CT. Models using baseline CT-FFR and EL were compared by analyzing the receiver operating characteristic (ROC) curve. ResultsOf the 94 vessels evaluated, 25 vessels (27 %) showed functional progression. EL at distal stenosis (ELdis) of vessels with functional progression was higher than that of vessels without functional progression (27.6 W/m3 [interquartile range (IQR): 15.0, 53.0] vs. 5.7 W/m3 [IQR: 2.3, 10.1], p < 0.001). Multivariable analysis showed that ELdis (per unit Ln(EL); odds ratio, 11.8; 95 % CI: 4.0–34.9; p < 0.001) remained as a predictor of functional progression after adjustment for diameter stenosis and baseline CT-FFR. The area under the ROC curve using ELdis (0.89; 95 % CI: 0.82–0.96) was higher than that using baseline CT-FFR (0.71; 95 % CI: 0.59–0.83; p < 0.001). ConclusionWhen ELdis and baseline CT-FFR were considered, ELdis was a better predictor of functional progression of coronary stenosis.

Формирование структурно-функциональной организации молодняков сосны обыкновенной (Pinus sylvestris L.) смешанного искусственно-естественного происхождения в условиях сосняков ягодникового и разнотравного Среднего Урала

Restoration of forests, the study of the processes of formation of their structure and productivity, is currently one of the most urgent tasks. The features of the formation of 12-year-old forest plantations and the concomitant natural regeneration of Scots pine (Pinus sylvestris L.) were studied under the conditions of berry pine forest and forb pine forest of the Middle Urals, on trial plots established in accordance with the existing requirements. For each Scotch pine (Pinus sylvestris L.) tree, the diameter at the middle height and height were measured, and the volume of the trunk in the bark was calculated. The rank distribution of trees was carried out by calculating their reduction numbers, determining the amplitude of the reduction numbers and subsequent distribution into 5 main classes. In the 12th year after planting, the survival rate in the berry pine forest was 47.0%, and in the forb pine forest - 35.3%. In the berry pine forest, taking into account the concomitant natural regeneration of Scots pine (Pinus sylvestris L.), a pine forest of artificial and natural origin is being formed, and in the forb pine forest, a pine forest of natural and artificial origin is being formed. The process of natural renewal of Scotch pine (Pinus sylvestris L.) took place over several years. Scots pine (Pinus sylvestris L.) trees of natural origin are 2-7 years younger in biological age than trees of artificial origin. Pine trees of artificial origin in the berry pine forest significantly exceed the average diameter at the middle of the height, height and trunk volume of the same trees in the forb pine forest. Pine trees of natural origin in the berry pine forest are significantly superior in average diameter at the middle of the height to trees in the forb pine forest, but they are significantly inferior to them in the average trunk height and practically do not differ in the average volume of the tree trunk. Trees of artificial origin in terms of diameter at the middle of the height, height and volume of the trunk significantly exceed trees of natural origin both in the berry pine forest and in the mixed grass pine forest. The distribution of trees by diameter and height in young forests of artificial and natural origin, both in the berry pine forest and in the forb pine forest, is characterized by a distribution close to normal. The distribution of trees of artificial and natural origin in the berry pine forest and the forb pine forest in terms of trunk volume is distinguished by left-sided asymmetry and sharpness. When distributed by rank height classes, a significant reduction in the level of variability of biometric indicators is provided. However, in natural young stands, a very high level of variability in stem volume in the bark remains. Both in artificial and natural young stands, the main (86.3-97.5%) stock of trunk wood in the bark falls on trees of I-III height classes. In the forb pine forest, artificial and natural young stands had almost the same reserve values, which confirms the formation of young pine stands of natural artificial origin. In the berry pine forest, birch renewal does not represent significant competition to pine. In the forb pine forest, birch creates serious competition for pine and, probably, the formation of deciduous-coniferous plantations and oppression of pine.

Dynamic CZT-SPECT: Characterizing the Lower Values of Myocardial Blood Flow and Reserve.

CZT-SPECT myocardial perfusion enables quantification of myocardial blood flow (MBF). Normal values and thresholds have been accurately defined in PET but remain unclear in SPECT. The aim of this study was to report normal MBF and myocardial flow reserve values in very low-risk patients referred for coronary artery disease screening with dynamic SPECT, in comparison with patients experiencing coronary artery disease. Eighty-four patients (31 male) were analyzed. The mean 10 years risk of fatal cardiovascular events score was 2.7% ± 1.4%. The mean global stress MBF and myocardial flow reserve were 1.6 ± 0.6 mL/min/g and 2.7 ± 0.7.

The prognostic value of coronary flow reserve in patients with non-obstructive coronary artery disease and microvascular dysfunction: a systematic review and meta-analysis with focus on imaging modality and sex difference.

To clarify prognosis of patients with non-obstructive coronary artery disease (NOCAD) and coronary microvascular disease (CMD) assessed as low coronary flow reserve (CFR) according to imaging modalities and sex difference. Comprehensive systematic literature review and meta-analyses were conducted. Risk of death and major adverse cardiac events (MACE) were pooled and compared in patients with abnormally low versus normal CFR using cut-off limits 2.0-2.5. Random effects model used for estimation of odds ratios (OR) and hazard ratios (HR) with 95% confidence interval (CI). Nineteen eligible observational studies provided data for death and MACE, publication bias was insignificant, p = 0.62. Risk of death and MACE were significantly higher in patients with low (n = 4.612, 29%) than normal CFR (n = 11.367, 71%): using transthoracal echocardiography (TTE) (OR 4.25 (95% CI 2.94, 6.15) p < 0.001) and (OR 6.98 (95% CI 2.56, 19.01) p < 0.001), positron emission tomography (PET) (OR 2.51 (CI 95%: 1.40, 4..49) p = 0.002) and (OR 2.87 (95% CI 2.16, 3.81) p < 0.001), and invasive intracoronary assessment (OR 2.23 (95% CI 1.15, 4.34) p < 0.018), and (OR 4.61 (95% CI 2.51, 8.48) p < 0.001), respectively. Pooled adjusted HR for death and MACE were (HR 2.45(95% CI 1.37, 3.53) p < 0.001) and (HR 2.08 (95% CI 1.54, 2.63) p < 0.001) respectively. Studies comparing men and women with abnormally low CFR demonstrated similar worse prognosis in both sexes. Low CFR is associated with poorer prognosis in patients with NOCAD regardless of sex. TTE may overestimate risk of death and MACE, while PET seems to be more appropriate. Future studies are needed to consolidate the current evidence.

Prognostic Value of Coronary CT Angiography-derived Fractional Flow Reserve on 3-year Outcomes in Patients with Stable Angina.

Background The prognostic value of coronary CT angiography (CTA)-derived fractional flow reserve (FFR) beyond 1-year outcomes and in patients with high levels of coronary artery calcium (CAC) is uncertain. Purpose To assess the prognostic value of coronary CTA-derived FFR test results on 3-year clinical outcomes in patients with coronary stenosis and among a subgroup of patients with high levels of CAC. Materials and Methods This study represents a 3-year follow-up of patients with new-onset stable angina pectoris who were consecutively enrolled in the Assessing Diagnostic Value of Noninvasive CT-FFR in Coronary Care, known as ADVANCE (ClinicalTrials.gov: NCT02499679) registry, between December 2015 and October 2017 at three Danish sites. A high CAC was defined as an Agatston score of at least 400. A lesion-specific coronary CTA-derived FFR value of 2 cm with distal-to-stenosis value at or below 0.80 represented an abnormal test result. The primary end point was a composite of all-cause death and nonfatal spontaneous myocardial infarction. Event rates were estimated using the one-sample binomial model, and relative risk was compared between participants stratified by results of coronary CTA-derived FFR. Results This study included 900 participants: 523 participants with normal results (mean age, 64 years ± 9.6 [SD]; 318 male participants) and 377 with abnormal results from coronary CTA-derived FFR (mean age, 65 years ± 9.6; 264 male participants). The primary end point occurred in 11 of 523 (2.1%) and 25 of 377 (6.6%) participants with normal and abnormal coronary CTA-derived FFR results, respectively (relative risk, 3.1; 95% CI: 1.6, 6.3; P < .001). In participants with high CAC, the primary end point occurred in four of 182 (2.2%) and 19 of 212 (9.0%) participants with normal and abnormal coronary CTA-derived FFR results, respectively (relative risk, 4.1; 95% CI: 1.4, 11.8; P = .001). Conclusion In individuals with stable angina, a normal coronary CTA-derived FFR test result identified participants with a low 3-year risk of all-cause death or nonfatal spontaneous myocardial infarction, both in the overall cohort and in participants with high CAC scores. Clinical trial registration no. NCT02499679 Published under a CC BY 4.0 license. Supplemental material is available for this article. See also the editorial by Sinitsyn in this issue.

An actuarial comparison of loss-ratio-Bornhuetter-Ferguson and classical chain ladder techniques in insurance loss reserving: A computational approach

An insurance firm promises to reimburse benefits to the insured when unforeseen events evolve. When such contingencies arise, the underwriter has a liability to pay the claim through loss reserving techniques. The estimation of such loss reserving should be technically performed so the insurance firm will not run into a loss. This study aims to (i) estimate the Bornheutter-Ferguson reserve and the inverse of its development factor λn under the aegis of the loss ratio framework. (ii) numerically estimate the chain ladder reserve and final losses, (iii) estimate the Ratio of cumulative payments in successive development periods, and (iv) demonstrate to professional insurance firms how to use these techniques in practice. These techniques evaluated through some run-off loss matrix can be employed to estimate technical provisions for the outstanding claims. Computational evidence from our results over the periods analyzed confirms that on the assumption of 0.9 the loss ratio, the Bornheutter- Ferguson technique as an actuarial extension of the chain ladder method numerically presents a lower reserve value than the corresponding chain ladder reserve, and hence CLreserve=249,811.708&gt;BFreserve=86,612.58.

PENGGUNAAN METODE BORNHUETTER-FERGUSON UNTUK ESTIMASI CADANGAN KLAIM

Health insurance company have to determine claim reserve that’s suitable with the existing condition. There is three party that’s involved in the health insurance management, namely the policy holder, Admedika as the third party administration, and also the insurance company itself as the (insurer). When the policy holder obtained treatments whose financing is done through a health insurance, then the health insurance company have the obligation to finish the financial matters. Delays in payments from insurance companies to health facilities are caused, among others, by the administrative process. Thus, every claim submitted by the insured party to the insurance company will be settled in stages to the health facilities. The data presented from these conditions form a triangle matrix (run-off triangle) which then becomes the basis for estimating the amount of IBNR claims reserves. The Bornhuetter-Ferguson (BF) method involves the amount of premium that has become income for the company and calculates the Ultimate Claim value in estimating the amount of claim reserves. This method is the result of the development of the previous method, Chain-Ladder (CL), which only relies on historical data on claim payments. Premium calculations need to be involved in health insurance, because the insurance period is short, which is only one year. Insurance companies haven't had time to turn around the money to invest, so payment of claims will depend more on the premium that becomes income for the company (earned premium). The estimated claim reserve value is more suitable and robust than the CL method. Estimated claim reserves that occur in the 2nd event period amount to IDR50,658,714 with an estimated interval for the 2nd event period between IDR10,215,477 and IDR91,101,950

Myocardial creep and cardiorespiratory motion correction improves diagnostic accuracy of Rubidium-82 cardiac positron emission tomography

AimTo evaluate the feasibility of retrospectively detecting and correcting periodical (cardiac and respiratory motion) and non-periodical shifts of the myocardial position (myocardial creep) using only the acquired Rubidium-82 positron emission tomography raw (listmode) data.MethodsThis study comprised 25 healthy participants (median age = 23 years) who underwent repeat rest/adenosine stress Rubidium-82 myocardial perfusion imaging (MPI) and 53 patients (median age = 64 years) considered for revascularization who underwent a single MPI session. All subjects were evaluated for myocardial creep during MPI by assessing the myocardial position every 200 ms. A proposed motion correction protocol, including corrections for cardiorespiratory and creep motion (3xMC), was compared to a guideline-recommended protocol (StandardRecon). For the volunteers, we report test-retest repeatability using standard error of measurements (SEM). For the patient cohort, we evaluated the area under the receiver operating curve (AUC) for both stress and ischemic total perfusion deficits (sTPD and iTPD, respectively) using myocardial ischemia defined as fractional flow reserve values < 0.8 in the relevant coronary segment as the gold standard.ResultsTest-retest repeatability was significantly improved following corrections for myocardial creep (SEM; sTPD: StandardRecon = 2.2, 3xMC = 1.8; iTPD: StandardRecon = 1.6, 3xMC = 1.2). AUC analysis of the ROC curves revealed significant improvements for iTPD measurements following 3xMC [sTPD: StandardRecon = 0.88, 3xMC = 0.92 (P = .21); iTPD: StandardRecon = 0.88, 3xMC = 0.95 (P = .039)].Conclusion3xMC has the potential to improve the diagnostic accuracy of myocardial MPI obtained from positron emission tomography. Therefore, its use should be considered both in clinical routine and large-scale multicenter studies.

Prognostic Value of Post-PCI Angiography-Derived Fractional Flow Reserve: A Systematic Review and Meta-Analysis of Cohort Studies.

The post-percutaneous coronary intervention (post-PCI) fractional flow reserve (FFR) can detect suboptimal PCI or residual ischemia and potentially lead to fewer adverse clinical outcomes. We sought to investigate the predictive value of the angiography-derived FFR for adverse cardiovascular events in patients after PCI. We conducted a comprehensive search of electronic databases, MEDLINE, EMBASE, and the Cochrane Library, for studies published until March 2023 that investigated the prognostic role of angiography-derived fractional flow reserve values after PCI. We investigated the best predictive ability of the post-PCI angiography-derived FFR and relative risk (RR) estimates with 95% confidence intervals (CIs) between post-PCI angiography-derived FFR values and adverse events. Thirteen cohort studies involving 6961 patients (9719 vascular lesions; mean follow-up: 2.2 years) were included in this meta-analysis. The pooled HR of the studies using specific cut-off points for post-PCI angiography-derived FFR was 4.13 (95% CI, 2.92-5.82) for total cardiovascular events, while the pooled HRs for target vessel revascularization, cardiac death, target vessel myocardial infarction, and target lesion revascularization were 6.87 (95% CI, 4.93-9.56), 6.17 (95% CI, 3.52-10.80), 3.98 (95% CI, 2.37-6.66) and 6.27 (95% CI, 3.08-12.79), respectively. In a sensitivity analysis of three studies with 1789 patients assessing the predictive role of the post-PCI angiography-derived FFR as a continuous variable, we found a 58% risk reduction for future adverse events per 0.1 increase in the post-PCI angiography-derived FFR value. In conclusion, post-PCI angiography-derived FFR is an effective tool for predicting adverse cardiovascular events and could be potentially used in decision making, both during PCI and in the long-term follow-up.

Applied coronary physiology for planning and guidance of percutaneous coronary interventions. A clinical consensus statement from the European Association of Percutaneous Cardiovascular Interventions (EAPCI) of the European Society of Cardiology.

The clinical value of fractional flow reserve and non-hyperaemic pressure ratios are well established in determining an indication for percutaneous coronary intervention (PCI) in patients with coronary artery disease (CAD). In addition, over the last 5 years we have witnessed a shift towards the use of physiology to enhance procedural planning, assess post-PCI functional results, and guide PCI optimisation. In this regard, clinical studies have reported compelling data supporting the use of longitudinal vessel analysis, obtained with pressure guidewire pullbacks, to better understand how obstructive CAD contributes to myocardial ischaemia, to establish the likelihood of functionally successful PCI, to identify the presence and location of residual flow-limiting stenoses and to predict long-term outcomes. The introduction of new functional coronary angiography tools, which merge angiographic information with fluid dynamic equations to deliver information equivalent to intracoronary pressure measurements, are now available and potentially also applicable to these endeavours. Furthermore, the ability of longitudinal vessel analysis to predict the functional results of stenting has played an integral role in the evolving field of simulated PCI. Nevertheless, it is important to have an awareness of the value and challenges of physiology-guided PCI in specific clinical and anatomical contexts. The main aim of this European Association of Percutaneous Cardiovascular Interventions clinical consensus statement is to offer up-to-date evidence and expert opinion on the use of applied coronary physiology for procedural PCI planning, disease pattern recognition and post-PCI optimisation.

Prognostic value of myocardial flow reserve derived by quantitative SPECT for patients with intermediate coronary stenoses

BackgroundFunctional assessment of myocardial ischemia is critical for patients with intermediate coronary stenosis. As the diagnosis performance of absolute quantification of myocardial blood flow (MBF) and myocardial flow reserve (MFR) by single-photon emission tomography (SPECT) has been proven, its prognostic value in patients with intermediate coronary stenosis remains to be evaluated. MethodsPatients with one or more target lesions of ≥ 50% to ≤ 80% diameter stenoses on invasive coronary angiography were prospectively included in this study. All patients were scheduled for clinically indicated SPECT myocardial perfusion imaging (MPI) within 3 months and agreed to provide informed consent to participate in quantitative SPECT acquisitions to obtain MBF and MFR values. The primary endpoint was defined as a composite of the major adverse cardiac events (MACE): Cardiac death, myocardial infarction, late revascularization and heart failure or unstable angina-related rehospitalization. ResultsOne hundred and nineteen patients (mean age 57 ± 8 years, 62.2% men) were included in the analysis. The average lumen stenosis of patients was 67.0 ± 10.4%. Over a median follow-up duration of 1408 days (interquartile range 1297-1666 days), 18 patients (15.1%) had MACE. Patients with impaired MFR (MFR < 2) had a significantly higher incidence of events than those with preserved MFR (MFR ≥ 2) in Kaplan-Meier survival analysis (Log-rank = 8.105, P = 0.004), while no significant difference was found between patients with normal relative perfusion and those with relative perfusion abnormalities (log-rank = 0.098, P > 0.05). In a multivariate Cox hazards analysis, the SPECT-derived MFR remained an independent predictor of MACE (HR 0.352, 95% CI 0.145-0.854, P = 0.021). ConclusionsIn a cohort of patients with angiographic intermediate coronary lesions, SPECT-derived MFR was an independent predictor of prognosis.

Dose-consistent dynamic SPECT

BackgroundCoronary flow reserve (CFR) values measured by dynamic SPECT systems are typically consistent with other modalities (e.g., PET). However, large discrepancies are often observed for individual patients. Positioning of the region-of-interest (ROI), representing the arterial input function (AIF) could explain some of these discrepancies. We explored the possibility of positioning the ROI in a manner that evaluates its consistency with patient-based injected radiotracer doses. MethodsDose-consistent dynamic SPECT methodology was introduced, and its application was demonstrated in a twenty-patient clinical study. The effect of various ROI positions was investigated and comparison to myocardial perfusion imaging was performed. ResultsMean AIF ratios were consistent with the injected dose ratios for all examined ROI positions. Good agreement (> 80%) between total perfusion deficit and CFR was found in the detection of obstructive CAD patients for all ROIs considered. However, for individual patients, significant dependence on ROI position was observed (altering CFR by typically 30%). The proposed methodology’s uncertainty was evaluated (~ 7%) and found to be smaller than the variability due to choice of ROI position. ConclusionDose-consistent dynamic SPECT may contribute to evaluating uncertainty of CFR measurements and may potentially decrease uncertainty by allowing improved ROI positioning for individual patients.