Clinical outcomes of patients with deferred revascularisation based on fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) negative coronary artery lesions in Pakistani population.

OBJECTIVE: To assess long-term clinical outcomes and factors associated with target vessel revascularisation in patients with deferred revascularisation based on negative fractional flow reserve and negative instantaneous wave-free ratio. METHODS: The longitudinal, retrospective study was conducted from July 1, 2020, to January 1, 2022, at the Aga Khan University Hospital, Karachi, and comprised medical records from January 2012 to January 2020 of patients with deferred revascularisation having intermediate to severe coronary lesions on coronary angiogram and had negative fractional flow reserve >0.80 or instantaneous wave-free ratio >0.89 and had not undergone immediate or planned revascularisation on the basis of negative physiological assessment. Data was collected from the institutional records, while final follow-up was taken by reviewing the medical records or telephonic interviews regarding any major adverse cardiac event after the index procedure. Data was analysed using Stata 14.2. RESULTS: Of the 345 patients, 245(71%) were males. The overall mean age was 62±11 years. There were 194(56%) patients who presented with stable angina and 151(44%) presented with acute coronary syndrome. Mean fractional flow reserve was 0.87±0.04 and mean instantaneous wave-free ratio was 0.93±0.03. Multivessel disease was present in 223(65%) patients. Median follow-up period was 29 months (IQR: 24-36 months). Major adverse cardiovascular events occurred in 22(6%) patients, and target vessel revascularisation was required in 11(3%). Diabetes and percentage of stenosis were found to be independent predictors of major adverse cardiovascular events (p<0.05). CONCLUSIONS: Deferral of revascularisation and opting for medical treatment for coronary artery stenosis with higher fractional flow reserve or instantaneous wave-free ratio could be considered a safe and reasonable strategy.

An Overview of Computational Coronary Physiology Technologies Based on Medical Imaging and Artificial Intelligence.

This article reviews four new technologies for assessment of coronary hemodynamics based on medical imaging and artificial intelligence, including quantitative flow ratio (QFR), optical flow ratio (OFR), computational fractional flow reserve (CT-FFR) and artificial intelligence (AI)-based instantaneous wave-free ratio (iFR). These technologies use medical imaging such as coronary angiography, computed tomography angiography (CTA), and optical coherence tomography (OCT), to reconstruct three-dimensional vascular models through artificial intelligence algorithms, simulate and calculate hemodynamic parameters in the coronary arteries, and achieve non-invasive and rapid assessment of the functional significance of coronary stenosis. This article details the working principles, advantages such as non-invasiveness, efficiency, accuracy, limitations such as image dependency, and assumption restrictions, of each technology. It also compares and analyzes the image dependency, calculation accuracy, calculation speed, and operation simplicity, of the four technologies. The results show that these technologies are highly consistent with the traditional invasive wire method, and shows distinct advantages in terms of accuracy, reliability, convenience and cost-effectiveness, but there are also factors that affect accuracy. The results of this review demonstrates that AI-based iFR technology is currently one of the most promising technologies. The main challenges and directions for future development are also discussed. These technologies bring new ideas for the non-invasive assessment of coronary artery disease, and are expected to promote the technological progress in this field.

Noninvasive and fast method of calculation for instantaneous wave-free ratio based on haemodynamics and deep learning.

BACKGROUND AND OBJECTIVES: Instantaneous wave-free ratio (iFR) is a new invasive indicator of myocardial ischaemia, and its diagnostic performance is as good as the "gold standard" of myocardial ischaemia diagnosis: fractional flow reserve (FFR). iFR can be approximated by iFRCT, which is calculated based on noninvasive coronary CT angiography (CTA) images and computational fluid dynamics (CFD). However, the existing methods for calculating iFRCT fail to accurately simulate the resting state of the coronary artery, resulting in low computational accuracy. Furthermore, the use of CFD technology limits its computational efficiency, making it difficult to meet clinical application needs. The role of coronary microcirculatory resistance compensation suggests that microcirculatory resistance can be adaptively reduced to compensate for increases in coronary stenotic resistance, thereby maintaining stable myocardial perfusion in the resting state. It is therefore necessary to consider this compensation mechanism to establish a high-fidelity microcirculation resistance model in the resting state in line with human physiology, and so to achieve accurate calculation of iFRCT. METHODS: In this study we successfully collected clinical data, such as FFR, in 205 stenotic vessels from 186 patients with coronary heart disease. A neural network model was established to predict coronary artery stenosis resistance. Based on the compensation mechanism of coronary microcirculation resistance, an iterative solution algorithm for microcirculation resistance in the resting state was developed. Combining the two methods, a simplified single-branch model combining coronary stenosis and microcirculation resistance was established, and the noninvasive and rapid numerical calculation of iFRCT was performed. RESULTS: The results showed that the mean squared error (MSE) between the pressure drop predicted by the neural network value for the coronary artery stenosis model and the ground truth in the test set was 0.053 %, and correlation analysis proved that there was a good correlation between them (r = 0.99, p < 0.001). With reference to clinical diagnosis of myocardial ischaemia (using FFR as the gold standard), the diagnostic accuracy of the iFRCT calculation model for the 205 cases was 88.29 % (r = 0.71, p < 0.001), and the total calculation time was < 8 s. CONCLUSIONS: The results of this study demonstrate the utility of a simplified single-branch model in an iFRCT calculation method based on haemodynamics and deep learning, which is important for noninvasive and rapid diagnosis of myocardial ischaemia.

Assessment of Coronary Stenoses for Percutaneous Coronary Intervention: A Systematic Review and Network Meta-Analysis of Randomized Trials.

Evidence regarding the comparative efficacy of the different methods to determine the significance of coronary stenoses in the catheterization laboratory is lacking. We aimed to compare all available methods guiding the decision to perform percutaneous coronary intervention (PCI). We searched Medline, Embase, and CENTRAL until October 5, 2023. We included trials that randomized patients with greater than 30% stenoses who were considered for PCI and reported major adverse cardiovascular events (MACE). We performed a frequentist random-effects network meta-analysis and assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We included 15 trials with 16,333 participants with a mean weighted follow-up of 34 months. The trials contained a median of 49.3% (interquartile range: 32.6%, 100%) acute coronary syndrome participants. Quantitative flow ratio (QFR) was associated with a decreased risk of MACE compared with coronary angiography (CA) (risk ratio [RR] 0.68, 95% confidence interval [CI] 0.56 to 0.82, high certainty), fractional flow reserve (FFR) (RR 0.73, 95% CI 0.58 to 0.92, moderate certainty), and instantaneous wave-free ratio (iFR) (RR 0.63, 95% CI 0.49 to 0.82, moderate certainty), and ranked first for MACE (88.1% probability of being the best). FFR (RR 0.93, 95% CI 0.82 to 1.06, moderate certainty) and iFR (RR 1.07, 95% CI 0.90 to 1.28, moderate certainty) likely did not decrease the risk of MACE compared with CA. Intravascular imaging may not be associated with a significant decrease in MACE compared with CA (RR 0.85, 95% CI 0.62 to 1.17, low certainty) when used to guide the decision to perform PCI. In conclusion, a decision to perform PCI based on QFR was associated with a decreased risk of MACE compared with CA, FFR, and iFR in a mixed stable coronary disease and acute coronary syndrome population. These hypothesis-generating findings should be validated in large, randomized, head-to-head trials.

Impact of coronary artery disease and revascularization on outcomes of transcatheter aortic valve replacement for severe aortic stenosis.

BACKGROUND/PURPOSE: To evaluate the impact of coronary artery disease (CAD), percutaneous coronary intervention (PCI), and coronary lesion complexity on outcomes of transcatheter aortic valve replacement (TAVR) for aortic stenosis. METHODS/MATERIALS: This retrospective study included 1042 patients divided into two groups by the presence or absence of CAD (SYNTAX score 0, no history of revascularization). Propensity score matching was used to compare the two groups. The effect of PCI, SYNTAX score, and residual SYNTAX score was also analyzed. RESULTS: The median age of the cohort was 82 years, and 641 patients had CAD. After propensity score matching, 346 pairs were analyzed. During 5 years of follow-up (median: 25, range 0-72 months), the rate of coronary intervention was significantly higher in CAD patients (p = 0.018). However, all-cause mortality, composite of all-cause mortality, stroke, and coronary intervention, and overt bleeding defined by VARC-3 were comparable. After stratification, in patients with creatinine ≥1.5 mg/dl, CAD was associated with a worse composite outcome (p = 0.016). Neither PCI nor SYNTAX score was associated with all-cause mortality in CAD patients. Similarly, residual SYNTAX score showed no association with mortality in patients undergoing PCI (all p values >0.7). PCI did not reach a significant difference in overt bleeding in CAD patients (adjusted p = 0.06). CONCLUSIONS: Despite a higher incidence of coronary interventions, major clinical outcomes were similar between patients with and without CAD after TAVR. In patients with chronic kidney disease, CAD may be associated with an adverse composite outcome. Neither PCI nor SYNTAX/residual SYNTAX score influenced all-cause mortality.

Physiological Assessment with iFR prior to FFR Measurement in Left Main Disease.

Despite guideline-based recommendation of the interchangeable use of instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) to guide revascularization decision-making, iFR/FFR could demonstrate different physiological or clinical outcomes in some specific patient or lesion subsets. Therefore, we sought to investigate the impact of difference between iFR and FFR-guided revascularization decision-making on clinical outcomes in patients with left main disease (LMD). In this international multicenter registry of LMD with physiological interrogation, we identified 275 patients in whom physiological assessment was performed with both iFR/FFR. Major adverse cardiovascular event (MACE) was defined as a composite of death, non-fatal myocardial infarction, and ischemia-driven target lesion revascularization. The receiver-operating characteristic analysis was performed for both iFR/FFR to predict MACE in respective patients in whom revascularization was deferred and performed. In 153 patients of revascularization deferral, MACE occurred in 17.0% patients. The optimal cut-off values of iFR and FFR to predict MACE were 0.88 (specificity:0.74; sensitivity:0.65) and 0.76 (specificity:0.81; sensitivity:0.46), respectively. The area under the curve (AUC) was significantly higher for iFR than FFR (0.74; 95%CI 0.62-0.85 vs. 0.62; 95%CI 0.48-0.75; p = 0.012). In 122 patients of coronary revascularization, MACE occurred in 13.1% patients. The optimal cut-off values of iFR and FFR were 0.92 (specificity:0.93; sensitivity:0.25) and 0.81 (specificity:0.047; sensitivity:1.00), respectively. The AUCs were not significantly different between iFR and FFR (0.57; 95%CI 0.40-0.73 vs. 0.46; 95%CI 0.31-0.61; p = 0.43). While neither baseline iFR nor FFR was predictive of MACE in patients in whom revascularization was performed, iFR-guided deferral seemed to be safer than FFR-guided deferral.

Validation of a new non-hyperemic physiological index: the constant-resistance ratio (cRR).

OBJECTIVES: The instantaneous wave-free ratio (iwFR) has limited availability. A new resting index called the constant-resistance ratio (cRR), which dynamically identifies cardiac intervals with constant and minimum resistance, has been developed; however, its diagnostic performance is unknown. The aim of this study was to validate the cRR by retrospectively calculating the cRR values from raw pressure waveforms of 2 publicly available datasets and compare them with those of the iwFR. METHODS: Waveform data from the CONTRAST and VERIFY 2 studies were used. The primary endpoint was Bland-Altman bias between cRR and iwFR. Secondary endpoints included diagnostic agreement, correlation, receiver operating characteristic (ROC) analysis, and success rates of cRR and iwFR. RESULTS: Among the 1036 waveforms, 871 were successful in determining paired cRR and iwFR values, while cRR was 6% more successful than iwFR (P less than .0001). The mean bias between cRR and iwFR was 0.003, with 95% limits of agreement [-0.021,0.028]. These 2 indices were highly correlated (r = 0.991; P less than .0001). Using an iwFR of 0.89 or less as the reference standard, the optimal cRR cutoff was 0.89, with an area under the ROC curve of 0.991 (P less than .001) and a diagnostic accuracy of 96.9% (95% CI [96%, 98%]). CONCLUSIONS: The cRR, a new resting index for identifying dynamic cardiac intervals with constant and minimum resistance, demonstrated high numerical agreement, diagnostic consistency, and a higher success rate than the iwFR based on the 2 publicly available datasets.

Coronary physiology instantaneous wave-free ratio (iFR) derived from x-ray angiography using artificial intelligence deep learning models: a pilot study.

OBJECTIVES: Coronary angiography (CAG)-derived physiology methods have been developed in an attempt to simplify and increase the usage of coronary physiology, based mostly on dynamic fluid computational algorithms. We aimed to develop a different approach based on artificial intelligence methods, which has seldom been explored. METHODS: Consecutive patients undergoing invasive instantaneous free-wave ratio (iFR) measurements were included. We developed artificial intelligence (AI) models capable of classifying target lesions as positive (iFR ≤ 0.89) or negative (iFR > 0.89). The predictions were then compared to the true measurements. RESULTS: Two hundred-fifty measurements were included, and 3 models were developed. Model 3 had the best overall performance: accuracy, negative predictive value (NPV), positive predictive value (PPV), sensitivity, and specificity were 69%, 88%, 44%, 74%, and 67%, respectively. Performance differed per target vessel. For the left anterior descending artery (LAD), model 3 had the highest accuracy (66%), while model 2 the highest NPV (86%) and sensitivity (91%). PPV was always low/modest. Model 1 had the highest specificity (68%). For the right coronary artery, model 1's accuracy was 86%, NPV was 97%, and specificity was 87%, but all models had low PPV (maximum 25%) and low/modest sensitivity (maximum 60%). For the circumflex, model 1 performed best: accuracy, NPV, PPV, sensitivity, and specificity were 69%, 96%, 24%, 80%, and 68%, respectively. CONCLUSIONS: We developed 3 AI models capable of binary iFR estimation from CAG images. Despite modest accuracy, the consistently high NPV is of potential clinical significance, as it would enable avoiding further invasive maneuvers after CAG. This pivotal study offers proof of concept for further development.

Clinical effects of physiologic lesion testing in influencing treatment strategy for multi-vessel coronary artery disease.

Background: The application of fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) in multivessel coronary artery disease (CAD) patients has not been definitively explored. We herein assessed how treatment strategies were decided based on FFR/iFR values in vessels selected clinically. Specifically, we sought to determine whether treatment selection was based on whether the vessel tested was the clinical target stenosis. Methods: 270 consecutive patients with angiographically determined multivessel disease who underwent FFR/iFR testing were included. Patients were classified initially based on their angiographic findings, then re-evaluated from FFR/iFR results (normal or abnormal). Tested lesions were classified into target or non-target lesions based on clinical and non-invasive evaluations. Results: Abnormal FFR/iFR values were demonstrated in 51.9 % of patients, in whom 51.4 % received coronary stenting (PCI) and 44.3 % had bypass surgery (CABG). With two-vessel CAD patients, medical therapy was preferred when the target lesion was normal (72.6 %), while PCI was preferred when it was abnormal (78.4 %). In non-target lesions, PCI was preferred regardless of FFR/iFR results (78.0 %). With three-vessel CAD patients, CABG was preferred when the target lesion was abnormal (68.5 %), and there was no difference in the selected modality when it was normal. Furthermore, the incidence of tested lesions was higher in the left anterior descending (LAD) compared to other coronary arteries, and two-vessel CAD patients with LAD stenoses were more frequently treated by PCI. Conclusion: The use of invasive physiologic testing in multivessel CAD patients may alter the preferred treatment strategy, leading to an overall increase in PCI selection.

Fractional flow reserve and instantaneous wave-free ratio in coronary artery bypass grafting: a meta-analysis and practice review.

Objective: Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are invasive methods to assess the functional significance of intermediate severity coronary lesions. Both indexes have been extensively validated in clinical trials in guiding revascularisation in patients with stable ischaemic heart disease undergoing percutaneous coronary intervention (PCI) with improved clinical outcomes. However, the role of these tools in coronary artery bypass grafting (CABG) is less clear. Methods: A meta-analysis of randomised trials and observational studies was carried out to help in determining the optimal strategy for assessing lesion severity and selecting graft targets in patients undergoing CABG. Electronic searches were carried out on Embase, MEDLINE, and Web of Science. A group of four authors independently screened and then assessed the retrieved records. Cochrane's Risk of Bias and Robins-I tools were used for bias assessment. A survey was conducted among surgeons and cardiologists to describe current attitudes towards the preoperative use of functional coronary investigations in practice. Results: Clinical outcomes including mortality at 30 days, perioperative myocardial infarction, number of grafts, incidence of stroke, rate of further need for revascularisation, and patient-reported quality of life did not differ in CABG guided by functional testing from those guided by traditional angiography.The survey revealed that in half of the surgical and cardiology units functional assessment is performed in CABG patients; there is a general perception that functional testing has improved patient care and its use would clarify the role of moderate coronary lesions that often need multidisciplinary rediscussions; moderate stenosis are felt to be clinically relevant; and anatomical considerations need to be taken into account together with functional assessment. Conclusions: At present, the evidence to support the routine use of functional testing in intermediate lesions for planning CABG is currently insufficient. The pooled data currently available do not show an increased risk in mortality, myocardial injury, and stroke in the FFR/iFR-guided group. Further trials with highly selected populations are needed to clarify the best strategy. Systematic Review Registration: ClinicalTrials.gov, identifier (CRD42023414604).

Sex Differences in 5-Year Outcomes After Deferral of Revascularization Following Physiological Coronary Assessment.

Background: The relationship between sex differences and long-term outcomes after fractional flow reserve (FFR)- and instantaneous wave-free ratio (iFR)-guided deferral of revascularization has yet to be elucidated. Methods and Results: From the J-CONFIRM registry (long-term outcomes of Japanese patients with deferral of coronary intervention based on FFR in a multicenter registry), this study included 432 lesions from 385 patients (men, 323 lesions in 286 patients; women, 109 lesions in 99 patients) with paired data of FFR and iFR. The primary endpoint was the cumulative 5-year incidence of target vessel failure (TVF), including cardiac death, target vessel-related myocardial infarction, and clinically driven target vessel revascularization. The median FFR value was lower in men than in women (0.85 [0.81, 0.88] vs. 0.87 [0.83, 0.91], P=0.002), but the iFR value was comparable between men and women (0.94 [0.90, 0.98] vs. 0.93 [0.89, 0.98], P=0.26). The frequency of discordance between FFR and iFR was comparable between men and women (19.5% vs. 23.9%, P=0.34), although with different discordance patterns (P=0.036). The cumulative incidence of 5-year TVF did not differ between men and women after adjustment for baseline characteristics (13.9% vs. 6.9%, adjusted hazard ratio 1.82 [95% confidence interval: 0.44-7.56]; P=0.41). Conclusions: Despite sex differences in the results for physiological indexes, the 5-year TVF in deferred lesions did not differ between men and women after adjustment for baseline characteristics.

Hemodynamic Insights into Combined Fractional Flow Reserve and Instantaneous Wave-Free Ratio Assessment Through Quantitative [15O]H2O PET Myocardial Perfusion Imaging.

In patients evaluated for obstructive coronary artery disease (CAD), guidelines recommend using either fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR) to guide coronary revascularization decision-making. The hemodynamic significance of lesions with discordant FFR and iFR measurements is debated. This study compared [15O]H2O PET-derived absolute myocardial perfusion between vessels with concordant and discordant FFR and iFR measurements. Methods: We included 197 patients suspected of obstructive CAD who had undergone [15O]H2O PET perfusion imaging and combined FFR/iFR interrogation in 468 vessels. Resting myocardial blood flow (MBF), hyperemic MBF, and coronary flow reserve (CFR) were compared among 4 groups: FFR low/iFR low (n = 79), FFR high/iFR low (n = 22), FFR low/iFR high (n = 22), and FFR high/iFR high (n = 345). Predefined [15O]H2O PET thresholds for ischemia were 2.3 mL·min-1·g-1 or less for hyperemic MBF and 2.5 or less for CFR. Results: Hyperemic MBF was lower in the concordant low (2.09 ± 0.67 mL·min-1·g-1), FFR high/iFR low (2.41 ± 0.80 mL·min-1·g-1), and FFR low/iFR high (2.40 ± 0.69 mL·min-1·g-1) groups compared with the concordant high group (2.91 ± 0.84 mL·min-1·g-1) (P < 0.001, P = 0.004, and P < 0.001, respectively). A lower CFR was observed in the concordant low (2.37 ± 0.76) and FFR high/iFR low (2.64 ± 0.84) groups compared with the concordant high group (3.35 ± 1.07, P < 0.01 for both). However, for vessels with either low FFR or low iFR, quantitative hyperemic MBF and CFR values exceeded the ischemic threshold in 38% and 49%, respectively. In addition, resting MBF exhibited a negative correlation with iFR (P < 0.001) and was associated with FFR low/iFR high discordance compared with concordant low FFR/low iFR measurements, independent of clinical and angiographic characteristics, as well as hyperemic MBF (odds ratio [OR], 0.41; 95% CI, 0.26-0.65; P < 0.001). Conclusion: We found reduced myocardial perfusion in vessels with concordant low and discordant FFR/iFR measurements. However, FFR/iFR combinations often inaccurately classified vessels as either ischemic or nonischemic when compared with hyperemic MBF and CFR. Furthermore, a lower resting MBF was associated with a higher iFR and the occurrence of FFR low/iFR high discordance. Our study showed that although combined FFR/iFR assessment can be useful to estimate the hemodynamic significance of coronary lesions, these pressure-derived indices provide a limited approximation of [15O]H2O PET-derived quantitative myocardial perfusion as the physiologic standard of CAD severity.

Comparison among various physiology and angiography-guided strategies for deferring percutaneous coronary intervention: A network meta-analysis.

BACKGROUND/PURPOSE: It is unclear whether coronary physiology or coronary angiography (CA)-guided strategy is the more preferable approach for deferring percutaneous coronary intervention (PCI). We sought to evaluate the clinical efficacy of various PCI strategies through a network meta-analysis of randomized controlled trials (RCTs). METHODS/MATERIALS: We searched multiple databases for RCTs investigating the impact of the following strategies for the purpose of determining whether or not to defer PCI: fractional flow reserve, instantaneous wave-free ratio, quantitative flow ratio (QFR), and CA. We conducted a network meta-analysis for trial-defined major adverse cardiovascular events (MACE), all-cause death, cardiovascular death, myocardial infarction (MI), target lesion revascularization (TLR), and stent thrombosis. We performed a subgroup analysis for those with acute coronary syndrome (ACS). RESULTS: Our search identified 12 eligible RCTs including a total of 13,177 patients. QFR-guided PCI was associated with reduced MACE, MI, and TLR compared with CA-guided PCI (relative risk (RR) 0.68; 95 % confidence interval (CI] [0.49 to 0.94], RR 0.58; 95 % CI [0.36 to 0.96], and RR 0.58; 95 % CI [0.38 to 0.91], respectively). There were no significant differences in any pairs for all-cause death, cardiovascular death, or stent thrombosis. QFR was ranked the best in most outcomes. In the subgroup analysis of the ACS cohort, there were no significant differences in MACE between any comparisons. CONCLUSIONS: QFR was associated with reduced MACE, MI, and TLR compared with CA, and ranked the best in most outcomes. However, this was not applied in the ACS cohort.

The ability of contemporary cardiologists to judge the ischemic impact of a coronary lesion visually.

BACKGROUND: Landmark trials showed that invasive pressure measurement (Fractional Flow Reserve, FFR) was a better guide to coronary stenting than visual assessment. However, present-day interventionists have benefited from extensive research and personal experience of mapping anatomy to hemodynamics. AIMS: To determine if visual assessment of the angiogram performs as well as invasive measurement of coronary physiology. METHODS: 25 interventional cardiologists independently visually assessed the single vessel coronary disease of 200 randomized participants in The Objective Randomized Blinded Investigation with optimal medical Therapy of Angioplasty in stable angina trial (ORBITA). They gave a visual prediction of the FFR and Instantaneous Wave-free Ratio (iFR), denoted vFFR and viFR respectively. Each judged each lesion on 2 occasions, so that every lesion had 50 vFFR, and 50 viFR assessments. The group consensus visual estimates (vFFR-group and viFR-group) and individual cardiologists' visual estimates (vFFR-individual and viFR-individual) were tested alongside invasively measured FFR and iFR for their ability to predict the placebo-controlled reduction in stress echo ischemia with stenting. RESULTS: Placebo-controlled ischemia improvement with stenting was predicted by vFFR-group (p < 0.0001) and viFR-group (p < 0.0001), vFFR-individual (p < 0.0001) and viFR-individual (p < 0.0001). There were no significant differences between the predictive performance of the group visual estimates and their invasive counterparts: p = 0.53 for vFFR vs FFR and p = 0.56 for viFR vs iFR. CONCLUSION: Visual assessment of the angiogram by contemporary experts, provides significant additional information on the amount of ischaemia which can be relieved by placebo-controlled stenting in single vessel coronary artery disease.

Comparison of Intravascular Imaging, Functional, or Angiographically Guided Coronary Intervention.

BACKGROUND: In patients undergoing percutaneous coronary intervention (PCI), it remains unclear whether intravascular imaging guidance or functional guidance is the best strategy to optimize outcomes and if the results are different in patients with vs without acute coronary syndromes (ACS). OBJECTIVES: The purpose of this study was to evaluate clinical outcomes with imaging-guided PCI or functionally guided PCI when compared with conventional angiography-guided PCI. METHODS: We searched PUBMED and EMBASE for randomized controlled trials investigating outcomes with intravascular imaging-guided, functionally guided, or angiography-guided PCI. The primary outcome from this network meta-analysis was trial-defined major adverse cardiovascular event (MACE)-a composite of cardiovascular death, myocardial infarction (MI), and target lesion revascularization (TLR). PCI strategies were ranked (best to worst) using P scores. RESULTS: Our search identified 32 eligible randomized controlled trials and included a total of 22,684 patients. Compared with angiography-guided PCI, intravascular imaging-guided PCI was associated with reduced risk of MACE (relative risk [RR]: 0.72; 95% CI: 0.62-0.82), cardiovascular death (RR: 0.56; 95% CI: 0.42-0.75), MI (RR: 0.81; 95% CI: 0.66-0.99), stent thrombosis (RR: 0.48; 95% CI: 0.31-0.73), and TLR (RR: 0.75; 95% CI: 0.57-0.99). Similarly, when compared with angiography-guided PCI, functionally guided PCI was associated with reduced risk of MACE and MI. Intravascular imaging-guided PCI ranked first for the outcomes of MACE, cardiovascular death, stent thrombosis, and TLR. The results were consistent in the ACS and non-ACS cohorts. CONCLUSIONS: Angiography-guided PCI had consistently worse outcomes compared with intravascular imaging-guided and functionally guided PCI. Intravascular imaging-guided PCI was the best strategy to reduce the risk of cardiovascular events.

The Impact of Age on the Physiological Assessment of Borderline Coronary Stenoses.

Background and Objectives: Coronary angiography is the gold standard for diagnosing coronary artery disease (CAD). In the case of borderline changes, patients require further diagnosis through ischemia assessment via one of the recommended methods of invasive evaluation. This study aimed to assess whether clinical factors influence the risk of a positive result in invasive myocardial ischemia assessment and if these potential factors change with the patient's age and the consistency of ischemia assessment. Materials and Methods: Data were collected retrospectively on all consecutive patients hospitalized in the University Hospital in Krakow between 2020 and 2021, on whom physiological assessments of coronary circulation were performed. Patients were divided into two groups: patients aged 60 or younger and patients older than 60. Results: Despite the older patients having more risk factors for CAD, their physiological assessment results of borderline lesions were similar to those of the younger patients. Positive fractional flow reserve (FFR) assessments were obtained from almost 50% of vessels. In the younger patients, cigarette use and type 2 diabetes mellitus increased the risk of a positive FFR result by 3.5 and 2.5 times, respectively. In the older patients, male gender and peripheral vascular disease significantly increased the risk of a positive FFR by 2.5 and 2 times, respectively. Conclusions: Clinical characteristics of patients undergoing physiological assessment of borderline coronary stenosis varied significantly by age. Refining the definition of borderline lesions to include age, gender, and other factors may improve the identification of patients who would benefit from physiological assessment and coronary revascularization.

Instantaneous wave free ratio vs. fractional flow reserve and 5-year mortality: iFR SWEDEHEART and DEFINE FLAIR.

BACKGROUND AND AIMS: Guidelines recommend revascularization of intermediate epicardial artery stenosis to be guided by evidence of ischaemia. Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are equally recommended. Individual 5-year results of two major randomized trials comparing FFR with iFR-guided revascularization suggested increased all-cause mortality following iFR-guided revascularization. The aim of this study was a study-level meta-analysis of the 5-year outcome data in iFR-SWEDEHEART (NCT02166736) and DEFINE-FLAIR (NCT02053038). METHODS: Composite of major adverse cardiovascular events (MACE) and its individual components [all-cause death, myocardial infarction (MI), and unplanned revascularisation] were analysed. Raw Kaplan-Meier estimates, numbers at risk, and number of events were extracted at 5-year follow-up and analysed using the ipdfc package (Stata version 18, StataCorp, College Station, TX, USA). RESULTS: In total, iFR and FFR-guided revascularization was performed in 2254 and 2257 patients, respectively. Revascularization was more often deferred in the iFR group [n = 1128 (50.0%)] vs. the FFR group [n = 1021 (45.2%); P = .001]. In the iFR-guided group, the number of deaths, MACE, unplanned revascularization, and MI was 188 (8.3%), 484 (21.5%), 235 (10.4%), and 123 (5.5%) vs. 143 (6.3%), 420 (18.6%), 241 (10.7%), and 123 (5.4%) in the FFR group. Hazard ratio [95% confidence interval (CI)] estimates for MACE were 1.18 [1.04; 1.34], all-cause mortality 1.34 [1.08; 1.67], unplanned revascularization 0.99 [0.83; 1.19], and MI 1.02 [0.80; 1.32]. CONCLUSIONS: Five-year all-cause mortality and MACE rates were increased with revascularization guided by iFR compared to FFR. Rates of unplanned revascularization and MI were equal in the two groups.