Blinded Physiological Assessment of Residual Ischemia After Successful Angiographic Percutaneous Coronary Intervention

Physiological Distribution and Local Severity of Coronary Artery Disease and Outcomes After Percutaneous Coronary Intervention

OBJECTIVES

The aim of this study was to evaluate prognostic implications of physiological 2-dimensional disease patterns on the basis of distribution and local severity of coronary atherosclerosis determined by quantitative flow ratio (QFR) virtual pull back.

BACKGROUND

The beneficial effect of percutaneous coronary intervention (PCI) is determined by physiological distribution and local severity of coronary atherosclerosis.

METHODS

The study population included 341 patients who underwent angiographically successful PCI and post-PCI fractional flow reserve (FFR) measurement. Using pre-PCI virtual pull backs of QFR, physiological distribution was determined by pull back pressure gradient index, with a cutoff value of 0.78 to define predominant focal versus diffuse disease. Physiological local severity was assessed by instantaneous QFR gradient per unit length, with a cutoff value of ≥0.025/mm to define a major gradient. Suboptimal post-PCI physiological results were defined as both post-PCI FFR ≤0.85 and percentage FFR increase ≤15%. Clinical outcome was assessed by target vessel failure (TVF) at 2 years.

RESULTS

QFR pull back pressure gradient index was correlated with post-PCI FFR (R = 0.423; P < 0.001), and instantaneous QFR gradient per unit length was correlated with percentage FFR increase (R = 0.370; P < 0.001). Using the 2 QFR-derived indexes, disease patterns were classified into 4 categories: predominant focal disease with and without major gradient (group 1 [n = 150] and group 2 [n = 21], respectively) and predominant diffuse disease with and without major gradient (group 3 [n = 115] and group 4 [n = 55], respectively). Proportions of suboptimal post-PCI physiological results were significantly different according to the 4 disease patterns (18.7%, 23.8%, 22.6%, and 56.4% from group 1 to group 4, respectively; P < 0.001). Cumulative incidence of TVF after PCI was significantly higher in patients with predominant diffuse disease (8.1% in group 3 and 9.9% in group 4 vs 1.4% in group 1 and 0.0% in group 2; overall P = 0.024).

CONCLUSIONS

Both physiological distribution and local severity of coronary atherosclerosis could be characterized without pressure-wire pull backs, which determined post-PCI physiological results. After successful PCI, TVF risk was determined mainly by the physiological distribution of coronary atherosclerosis. (Automated Algorithm Detecting Physiologic Major Stenosis and Its Relationship With Post-PCI Clinical Outcomes [Algorithm-PCI], NCT04304677; Influence of FFR on the Clinical Outcome After Percutaneous Coronary Intervention [PERSPECTIVE], NCT01873560).

Prognostic value of platelet/lymphocyte ratio and CAMI-STEMI score for major adverse cardiac events in patients with acute ST segment elevation myocardial infarction after percutaneous coronary intervention: A prospective observational study

The aim of this study was to investigate the predictive value of the platelet-to-lymphocyte ratio (PLR) and the China Acute Myocardial Infarction registry-ST segment elevation myocardial infarction (CAMI-STEMI) score for major adverse cardiovascular events (MACE) in ST-segment elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PCI) within 6 months.We enrolled STEMI patients who received emergency PCI in the First Hospital of Lianyungang from January 2016 to December 2019. The clinical characteristics of the patients, the PLR, and the CAMI-STEMI score were recorded. The MACE included heart failure, nonfatal re-infarction, recurrent angina pain, re-hospitalization for cardiovascular-related illness, repeat PCI, coronary artery bypass grafting, and all-cause mortality. According to the incidence of MACE during the follow-up the patients were divided into the MACE group (96 cases, 24.8%) and the non-MACE group (291 cases, 75.2%).The PLR, 147.62 (121.13-205.20) in MACE group, was 111.19 (90.23-146.42) in the non-MACE group in comparison, the PLR was higher in MACE group than that in non-MACE group (P < .01). Multivariate regression analysis showed that PLR (odds ratio (OR) = 1.007, 95% confidence interval (CI) 1.002-1.012, P < .01) and CAMI-STEMI score (OR = 1.575, 95% CI: 1.311-1.892, P < .01) were independent predictors of MACE. Besides, I-BIL was also an independent predictor of MACE (OR = 1.007, 95% CI: 1.011-1.146, P = .021). Reciever-operating characteristic curve showed that the area under curve of PLR was 0.704 (95%CI 0.644-0.763, P < .001). The cutoff value was 112.6, the sensitivity and specificity were 84.4% and 51.9%, respectively.PLR and CAMI-STEMI scores were independent risk factors of MACE after PCI in STEMI patients.

Invasive Coronary Physiology After Stent Implantation: Another Step Toward Precision Medicine

Intracoronary physiology is routinely used in setting the indication for percutaneous coronary intervention (PCI) but seldom in assessing procedural results. This attitude is increasingly challenged by accumulated evidence demonstrating the value of post-PCI functional assessment in predicting long-term patient outcomes. Besides fractional flow reserve, a number of new indexes recently incorporated to clinical practice, including nonhyperemic pressure and functional angiographic indexes, provide new opportunities for the physiological assessment of PCI results. Largely, the benefit of these tools is derived from longitudinal analysis of the treated vessel, which allows precise identification of the vessel segment accounting for a suboptimal functional result and enabling operators to perform accurate PCI optimization. In this document the authors review available evidence supporting why physiological assessment should be extended to immediate post-PCI with the aim of improving patient outcomes. A step-by-step guide on how available physiological tools can be used for such purpose is provided.

Immediate post-procedural functional assessment of percutaneous coronary intervention: current evidence and future directions

Percutaneous coronary intervention (PCI) guided by coronary physiology provides symptomatic benefit and improves patient outcomes. Nevertheless, over one-fourth of patients still experience recurrent angina or major adverse cardiac events following the index procedure. Coronary angiography, the current workhorse for evaluating PCI efficacy, has limited ability to identify suboptimal PCI results. Accumulating evidence supports the usefulness of immediate post-procedural functional assessment. This review discusses the incidence and possible mechanisms behind a suboptimal physiology immediately after PCI. Furthermore, we summarize the current evidence base supporting the usefulness of immediate post-PCI functional assessment for evaluating PCI effectiveness, guiding PCI optimization, and predicting clinical outcomes. Multiple observational studies and post hoc analyses of datasets from randomized trials demonstrated that higher post-PCI functional results are associated with better clinical outcomes as well as a reduced rate of residual angina and repeat revascularization. As such, post-PCI functional assessment is anticipated to impact patient management, secondary prevention, and resource utilization. Pre-PCI physiological guidance has been shown to improve clinical outcomes and reduce health care costs. Whether similar benefits can be achieved using post-PCI physiological assessment requires evaluation in randomized clinical outcome trials.

Coronary physiologic assessment based on angiography and intracoronary imaging

Despite the current evidence supporting clinical benefits of fractional flow reserve (FFR), its uptake in the cardiac catheterization laboratory has been slow due to procedural cost and increased time with the need for maximum hyperemia. Recently, novel physiological indices derived from coronary angiography and intracoronary imaging have emerged to overcome issues with a wire-based FFR. Angiography-based FFR can be measured without vessel instrumentation and has shown excellent diagnostic performance using wire-based FFR as the reference standard. Thus, angiography-based FFR may facilitate coronary functional assessment before and after percutaneous coronary intervention (PCI). Angiography-based index of microcirculatory resistance (IMR) is another new computational index for assessing the coronary microcirculation. Although angiography-derived IMR remains in an early phase of development and requires further validation, its less-invasive nature may help broaden the adoption of microvascular functional assessment in various conditions such as myocardial infarction and cardiac allograft vasculopathy. Lastly, computational FFR based on intravascular ultrasound and optical coherence tomography allows detailed lesion assessment from both morphological and functional standpoints. Given a growing interest in physiology-guided PCI optimization strategies, intravascular imaging-based FFR may become the main assessment tool to confirm successful PCI.

Placebo-Controlled Efficacy of Percutaneous Coronary Intervention for Focal and Diffuse Patterns of Stable Coronary Artery Disease

[Figure: see text].

Post-stenting fractional flow reserve vs coronary angiography for optimisation of percutaneous coronary intervention: TARGET-FFR trial

Aims 

A fractional flow reserve (FFR) value ≥0.90 after percutaneous coronary intervention (PCI) is associated with a reduced risk of adverse cardiovascular events. TARGET-FFR is an investigator-initiated, single-centre, randomized controlled trial to determine the feasibility and efficacy of a post-PCI FFR-guided optimization strategy vs. standard coronary angiography in achieving final post-PCI FFR values ≥0.90.

Methods and results 

After angiographically guided PCI, patients were randomized 1:1 to receive a physiology-guided incremental optimization strategy (PIOS) or a blinded coronary physiology assessment (control group). The primary outcome was the proportion of patients with a final post-PCI FFR ≥0.90. Final FFR ≤0.80 was a prioritized secondary outcome. A total of 260 patients were randomized (131 to PIOS, 129 to control) and 68.1% of patients had an initial post-PCI FFR <0.90. In the PIOS group, 30.5% underwent further intervention (stent post-dilation and/or additional stenting). There was no significant difference in the primary endpoint of the proportion of patients with final post-PCI FFR ≥0.90 between groups (PIOS minus control 10%, 95% confidence interval −1.84 to 21.91, P = 0.099). The proportion of patients with a final FFR ≤0.80 was significantly reduced when compared with the angiography-guided control group (−11.2%, 95% confidence interval −21.87 to −0.35], P = 0.045).

Conclusion 

Over two-thirds of patients had a physiologically suboptimal result after angiography-guided PCI. An FFR-guided optimization strategy did not significantly increase the proportion of patients with a final FFR ≥0.90, but did reduce the proportion of patients with a final FFR ≤0.80.

Percutaneous Coronary Revascularization: JACC Historical Breakthroughs in Perspective

Over the last 4 decades, percutaneous coronary intervention has evolved dramatically and is now an acceptable treatment option for patients with advanced coronary artery disease. However, trialists have struggled to establish the respective roles for percutaneous coronary intervention and coronary artery bypass graft surgery, especially in patients with multivessel disease and unprotected left-main stem coronary artery disease. Several pivotal trials and meta-analyses comparing these 2 revascularization strategies have enabled the relative merits of each technique to be established with regard to the type of ischemic syndrome, the coronary anatomy, and the patient's overall comorbidity. Precision medicine with individualized prognosis is emerging as an important method of selecting treatment. However, the never-ending advancement of technology, in conjunction with the emergence of novel pharmacological agents, will in the future continue to force us to reconsider the evolving question: "Which treatment strategy is better and for which patient?"

Derivation and validation of Pd/Pa in the assessment of residual ischemia post-intervention: A prospective all-comer registry

BACKGROUND

Measurement of post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) demonstrates residual ischemia in a large percentage of cases deemed angiographically successful which, in turn, has been associated with worse long-term outcomes. It has recently been shown that a resting pressure index, Pd/Pa, has prognostic value post stenting, however, its diagnostic value relative to FFR post-PCI has not been evaluated.

METHODS

The diagnostic accuracy of Pd/Pa in identifying ischemia (FFR≤0.80) pre- and post-PCI was evaluated. Three patient subsets were analyzed. A reference pre-PCI cohort of 1,255 patients (1,560 vessels) was used to measure the accuracy of pre-PCI Pd/Pa vs. FFR. A derivation post-PCI group of 574 patient (664 vessels) was then used to calculate the diagnostic accuracy of post-PCI Pd/Pa vs. FFR. A final prospective validation cohort of 230 patients (255 vessels) was used to test and validate the diagnostic performance of post-PCI Pd/Pa.

RESULTS

Median Pd/Pa and FFR were 0.90 (IQR 0.90-0.98) and 0.80 (IQR 0.71-0.88) in the reference pre-PCI model, 0.96 (IQR 0.93-1.00) and 0.87 (IQR 0.77-0.90) in the post-PCI derivation model, and 0.94 (IQR 0.89-0.97) and 0.84 (IQR 0.77-0.90) in the post-PCI validation model respectively. There was a strong linear correlation between Pd/Pa and FFR in all three models (p < 0.0001). Using ROC analysis, the optimal Pd/Pa cutoff value to predict a FFR ≤ 0.80 was ≤0.92 (AUC 0.87) in the pre-PCI model, ≤0.93 (AUC 0.85) in the post-PCI derivation model, and ≤ 0.90 (AUC 0.91) in the post-PCI validation model. Using a hybrid strategy of post-PCI Pd/Pa and post-PCI FFR when necessary (25% patients), overall diagnostic accuracy was improved to 95%.

CONCLUSIONS

Pd/Pa has excellent diagnostic accuracy for identifying ischemia post-intervention. Using a hybrid strategy of post-PCI Pd/Pa first, and FFR afterwards, if required, adenosine administration can be avoided in over 75% of physiologic assessments post intervention.

Physiology-Based Revascularization: A New Approach to Plan and Optimize Percutaneous Coronary Intervention

Coronary physiological assessment using fractional flow reserve or nonhyperemic pressure ratios has become a standard of care for patients with coronary atherosclerotic disease. However, most evidence has focused on the pre-interventional use of physiological assessment to aid revascularization decision-making, whereas post-interventional physiological assessment has not been well established. Although evidence for supporting the role of post-interventional physiological assessment to optimize immediate revascularization results and long-term prognosis has been reported, a more thorough understanding of these data is crucial in incorporating post-interventional physiological assessment into daily practice. Recent scientific efforts have also focused on the potential role of pre-interventional fractional flow reserve or nonhyperemic pressure ratio pullback tracings to characterize patterns of coronary atherosclerotic disease to better predict post-interventional physiological outcomes, and thereby identify the appropriate revascularization target. Pre-interventional pullback tracings with dedicated post-processing methods can provide characterization of focal versus diffuse disease or major gradient versus minor gradient stenosis, which would result in different post-interventional physiological results. This review provides a comprehensive look at the current evidence regarding the evolving role of physiological assessment as a functional optimization tool for the entire process of revascularization, and not merely as a pre-interventional tool for revascularization decision-making.

Comparison of the incidence of periprocedural myocardial infarction between percutaneous coronary intervention with versus without rotational atherectomy using propensity score-matching

Complications such as slow flow are frequently observed in percutaneous coronary intervention (PCI) with rotational atherectomy (RA). However, it remains unclear whether the high incidence of slow flow results in the high incidence of periprocedural myocardial infarction (PMI), reflecting real myocardial damage. The aim of this study was to compare the incidence of PMI between PCI with versus without RA using propensity score-matching. We included 1350 elective PCI cases, which were divided into the RA group (n = 203) and the non-RA group (n = 1147). After propensity score matching, the matched RA group (n = 190) and the matched non-RA group (n = 190) were generated. The primary interest was to compare the incidence of PMI between the matched RA and non-RA groups. Before propensity score matching, the incidence of slow flow and PMI was greater in the RA group than in the non-RA group. After matching, the incidence of slow flow was still greater in the matched RA group than in the matched non-RA group (16.8% vs. 9.5%, p = 0.048). However, the incidence of PMI was similar between the matched RA and matched non-RA group (7.4% vs. 5.3%, p = 0.528, standardized difference: 0.086). In conclusion, although use of RA was associated with greater risk of slow flow, use of RA was not associated with PMI after a propensity score-matched analysis. The fact that RA did not increase the risk of myocardial damage in complex lesions would have an impact on revascularization strategy for severely calcified coronary lesions.

Ten-Year All-Cause Death According to Completeness of Revascularization in Patients With Three-Vessel Disease or Left Main Coronary Artery Disease: Insights From the SYNTAX Extended Survival Study

BACKGROUND

Ten-year all-cause death according to incomplete (IR) versus complete revascularization (CR) has not been fully investigated in patients with 3-vessel disease and left main coronary artery disease undergoing percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG).

METHODS

The SYNTAX Extended Survival study (Synergy Between PCI With TAXUS and Cardiac Surgery: SYNTAX Extended Survival [SYNTAXES]) evaluated vital status up to 10 years in patients who were originally enrolled in the SYNTAX trial. In the present substudy, outcomes of the CABG CR group were compared with the CABG IR, PCI CR, and PCI IR groups. In addition, in the PCI cohort, the residual SYNTAX score (rSS) was used to quantify the extent of IR and to assess its association with fatal late outcome. The rSS of 0 suggests CR, whereas a rSS>0 identifies the degree of IR.

RESULTS

IR was more frequently observed in patients with PCI versus CABG (56.6% versus 36.8%) and more common in those with 3-vessel disease than left main coronary artery disease in both the PCI arm (58.5% versus 53.8%) and the CABG arm (42.8% versus 27.5%). Patients undergoing PCI with CR had no significant difference in 10-year all-cause death compared with those undergoing CABG (22.2% for PCI with CR versus 24.3% for CABG with IR versus 23.8% for CABG with CR). In contrast, those with PCI and IR had a significantly higher risk of all-cause death at 10 years compared with CABG and CR (33.5% versus 23.7%; adjusted hazard ratio, 1.48 [95% CI, 1.15-1.91]). When patients with PCI were stratified according to the rSS, those with a rSS≤8 had no significant difference in all-cause death at 10 years as the other terciles (22.2% for rSS=0 versus 23.9% for rSS>0-4 versus 28.9% for rSS>4-8), whereas a rSS>8 had a significantly higher risk of 10-year all-cause death than those undergoing PCI with CR (50.1% versus 22.2%; adjusted hazard ratio, 3.40 [95% CI, 2.13-5.43]).

CONCLUSIONS

IR is common after PCI, and the degree of incompleteness was associated with 10-year mortality. If it is unlikely that complete (or nearly complete; rSS<8) revascularization can be achieved with PCI in patients with 3-vessel disease, CABG should be considered. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00114972. URL: https://www.clinicaltrials.gov; Unique identifier: NCT03417050.

Multicenter clinical evaluation of a piezoresistive-MEMS-sensor rapid-exchange pressure microcatheter system for fractional flow reserve measurement

Objectives

This multicenter, prospective clinical study investigates whether the microelectromechanical‐systems‐(MEMS)‐sensor pressure microcatheter (MEMS‐PMC) is comparable to a conventional pressure wire in fractional flow reserve (FFR) measurement.

Background

As a conventional tool for FFR measurement, pressure wires (PWs) still have some limitations such as suboptimal handling characteristics and unable to maintain the wire position during pullback assessment. Recently, a MEMS‐PMC compatible with any 0.014″ guidewire is developed. Compared with the existing optical‐sensor PMC, this MEMS‐PMC has smaller profiles at both the lesion crossing and sensor packaging areas.

Methods

Two hundred and forty‐two patients with visually 30–70% coronary stenosis were enrolled at four centers. FFR was measured first with the MEMS‐PMC, and then with the PW. The primary endpoint was the Bland–Altman mean bias between the MEMS‐PMC and PW FFR.

Results

From the 224‐patient per‐protocol data, quantitative coronary angiography showed 17.9% and 55.9% vessels had diameter < 2.5 mm and stenosis >50%, respectively. The two systems' mean bias was −0.01 with [−0.08, 0.06] 95% limits‐of‐agreement. Using PW FFR≤0.80 as cutoff, the MEMS‐PMC per‐vessel diagnostic accuracy was 93.4% [95% confidence interval: 89.4–96.3%]. The MEMS‐PMC's success rate was similar to that of PW (97.5 vs. 96.3%, p = .43) with no serious adverse event, and its clinically‐significant (>0.03) drift rate was 43% less (9.5 vs. 16.7%, p = .014).

Conclusions

Our study showed the MEMS‐PMC is safe to use and has a minimal bias equal to the resolution of current FFR systems. Given the MEMS‐PMC's high measurement accuracy and rapid‐exchange nature, it may become an attractive new tool facilitating routine coronary physiology assessment.

Optimising physiological endpoints of percutaneous coronary intervention

Invasive coronary physiology to select patients for coronary revascularisation has become established in contemporary guidelines for the management of stable coronary artery disease. Compared to revascularisation based on angiography alone, the use of coronary physiology has been shown to improve clinical outcomes and cost efficiency. However, recent data from randomised controlled trials have cast doubt upon the value of ischaemia testing to select patients for revascularisation. Importantly, 20-40% of patients have persistence or recurrence of angina after angiographically successful percutaneous coronary intervention (PCI). This state-of-the-art review is focused on the transitioning role of invasive coronary physiology from its use as a dichotomous test for ischaemia with fixed cut-points, towards its utility for real-time guidance of PCI to optimise physiological results. We summarise the contemporary evidence base for ischaemia testing in stable coronary artery disease, examine emerging indices which allow advanced physiological guidance of PCI, and discuss the rationale and evidence base for post-PCI physiological assessments to assess the success of revascularisation.

Assessing the Accuracy of a second-generation optical sensor pressor wire in a wire to wire comparison (The ACCURACY study)

BACKGROUND

The phenomenon of "pressure drift" increases uncertainty about the correct FFR value. Redesigned and incorporating an optical pressure sensor, the "OptoWire Deux™" is purported to be less prone to the pressure drift seen with piezoelectric coronary pressure wires. The aim of this first in vivo real-world clinical study is to evaluate the performance of OptoWire Deux™ in terms of measurements agreement and propensity to pressure drift in a wire to wire comparison.

METHODS

This is a single center, prospective, non-blinded clinical investigation enrolling 45 consecutive patients with a clinical indication for coronary lesion FFR assessment. Lesions were either simultaneously assessed with two optical sensor pressure wires (OSPW) (Group O-O; 30 patients, 34 lesions) or one OSPW and one piezoelectric pressure wire (PEPW) simultaneously (Group O-P; 15 patients, 15 lesions). Significant drift was defined as a pressure ratio deviation of >0.03.

RESULTS

Mean FFR measurements in Group OO were not statistically different between the two sets of OSPW (overall 0.84±0.10; P = 0.52). In Group OP, however, mean FFR measurement with PEPW (0.85±0.09) was numerically lower than that observed with the OSPW (0.88±0.08; P = 0.09). Level of agreement using the Bland-Altman method was higher when 2 OSPW were used for FFR assessment (-0.002 95% CI [-0.033,0.029] vs. 0.026 95% CI [-0.078, 0.130], respectively). The rate of drift was significantly lower with an OSPW compared to a PEPW (4.8% vs. 26.7% respectively, P = 0.02).

CONCLUSION

The optical sensor guidewire showed a high level of readings' agreement after simultaneous usage of 2 optical sensor guidewires. There was also significantly less drift when compared to a piezoelectric guidewire.

Physiologic Assessment after Coronary Stent Implantation

The presence of myocardial ischemia is a prerequisite for the benefit of coronary revascularization. In the cardiac catheterization laboratory, fractional flow reserve and non-hyperemic pressure ratios are used to define the ischemia-causing coronary stenosis, and several randomized studies showed the benefit of physiology-guided coronary revascularization. However, physiology-guided revascularization does not necessarily guarantee the relief of ischemia. Recent studies reported that residual ischemia might exist in up to 15-20% of cases after angiographically successful percutaneous coronary intervention (PCI). Therefore, post-PCI physiologic assessment is necessary for judging the appropriateness of PCI, detecting the lesions that may benefit from additional PCI, and risk stratification after PCI. This review will focus on the current evidence for post-PCI physiologic assessment, how to interpret these findings, and the future perspectives of physiologic assessment after PCI.

Physiology-Based Revascularization of Left Main Coronary Artery Disease

It is of critical importance to correctly assess the significance of a left main lesion. Underestimation of significance beholds the risk of inappropriate deferral of revascularization, whereas overestimation may trigger major but unnecessary interventions. This article addresses the invasive physiological assessment of left main disease and its role in deciding upon revascularization. It mainly focuses on the available evidence for fractional flow reserve and instantaneous wave-free ratio, their interpretation, and limitations. We also discuss alternative invasive physiological indices and imaging, as well as the link between physiology, ischemia, and prognosis.

How to select patients requiring coronary revascularisation using coronary physiology

The coronary angiogram is an indicator of flow limiting coronary artery disease but coronary physiology at the time of angiography is vital in assessing the true functional significance of coronary artery disease. With advances in guidewire technology and the greater use of physiology within the catheter laboratory, there is now a slow evolution of physiological indices in being able to reliably assess the functional significance of individual lesions and also the adequacy of revascularization in a growing range of clinical scenarios. As co-registration of physiology with the angiogram and intravascular imaging will become easier, we will find ourselves increasingly in an era of 'Precision PCI'.

Predicting post stent fractional flow reserve virtually from quantitative flow ratio - Can we really get there from here?

This study compared virtual (residual) post-PCI QFR and actual post-PCI QFR from pre- and post-stent angiograms in predicting post-PCI FFR. While there was no difference in mean values, compared with post-PCI FFR, the post-PCI QFR correlated better than residual QFR. As the CFD algorithms improve, post-PCI QFR can potentially serve as a quality control after PCI to reduce post-PCI angina and adverse outcomes.

Complete versus incomplete coronary revascularization: definitions, assessment and outcomes

Coronary artery disease is the leading cause of morbidity and mortality worldwide. Selected patients with obstructive coronary artery disease benefit from revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery. Many (but not all) studies have demonstrated increased survival and greater freedom from adverse cardiovascular events after complete revascularization (CR) than after incomplete revascularization (ICR) in patients with multivessel disease. However, achieving CR after PCI or CABG surgery might not be feasible owing to patient comorbidities, anatomical factors, and technical or procedural considerations. These factors also mean that comparisons between CR and ICR are subject to multiple confounders and are difficult to understand or apply to real-world clinical practice. In this Review, we summarize and critically appraise the evidence linking various types of ICR to adverse outcomes in patients with multivessel disease and stable ischaemic heart disease, non-ST-segment elevation acute coronary syndrome or ST-segment elevation myocardial infarction, with or without cardiogenic shock. In addition, we provide practical recommendations for revascularization in patients with high-risk multivessel disease to optimize their long-term clinical outcomes and identify areas requiring future clinical investigation.

Clinical implication of QFR in patients with ST-segment elevation myocardial infarction after drug-eluting stent implantation

The feasibility and prognostic value of quantitative flow ratio (QFR) after percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) patients have not been assessed. The aim of this study was to investigate the prognostic utility of post-PCI QFR to predict outcomes in STEMI and determine the influence of functional results, in both culprit and nonculprit lesions, after PCI. Patients undergoing PCI of culprit lesions and receiving staged procedures of nonculprit lesions after 7 days were enrolled from 2 centers and underwent post-PCI QFR. The primary outcome was the vessel-oriented composite endpoints (VOCEs), defined as vessel-related cardiovascular death, vessel-related myocardial infarction, and target vessel revascularization. Four hundred fifteen vessels (186 culprit lesions and 219 nonculprit lesions) in 186 patients were analyzed. Measured at staged PCI, the post-PCI QFR of culprit lesions was significantly lower than that of nonculprit lesions (0.92 ± 0.10 versus 0.95 ± 0.08, p < 0.001). The multivariable model demonstrated that low post-PCI QFR was an independent predictor of 2-year VOCE (20.8% versus 5.7%; hazard ratio 2.718; 95% CI 1.347-5.486; p = 0.005). In STEMI patients with a low angiography-derived index of microcirculatory resistance (≤ 40U), a good correlation and agreement between post-PCI QFR value of culprit lesions at primary and staged procedures (r = 0.942; mean difference: - 0.0017 [- 0.074 to 0.070]) was identified. In conclusion, culprit lesions suffered from suboptimal functional results more frequently compared to nonculprit lesions after PCI in STEMI patients. Low post-PCI QFR was associated with subsequent adverse clinical outcomes. After stenting, culprit lesions may feasibly be assessed through QFR without significant microvascular dysfunction.

Validation of novel 3-dimensional quantitative coronary angiography based software to calculate fractional flow reserve post stenting

Objectives

To validate novel dedicated 3D‐QCA based on the software to calculate post PCI vessel‐FFR (vFFR) in a consecutive series of patients, to assess the diagnostic accuracy, and to assess inter‐observer variability.

Background

Low post percutaneous coronary intervention (PCI) fractional flow reserve (FFR) predicts future adverse cardiac events. However, FFR assessment requires the insertion of a pressure wire in combination with the use of a hyperemic agent.

Methods

FAST POST study is an observational, retrospective, single‐center cohort study. One hundred patients presenting with stable angina or non ST‐elevation myocardial infarction, who underwent post PCI FFR assessment using a dedicated microcatheter were included. Two orthogonal angiographic projections were acquired to create a 3D reconstruction of the coronary artery using the CAAS workstation 8.0. vFFR was subsequently calculated using the aortic root pressure.

Results

Mean age was 65±12 years and 70% were male. Mean microcatheter based FFR and vFFR were 0.91±0.07 and 0.91±0.06, respectively. A good linear correlation was found between FFR and vFFR (r = 0.88; p <.001). vFFR had a higher accuracy in the identification of patients with FFR values <0.90, AUC 0.98 (95% CI: 0.96‐1.00) as compared with 3D‐QCA AUC 0.62 (95% CI: 0.94‐0.74). Assessment of vFFR had a low inter‐observer variability (r = 0.95; p <.001).

Conclusion

3D‐QCA derived post PCI vFFR correlates well with invasively measured microcatheter based FFR and has a high diagnostic accuracy to detect FFR <0.90 with low inter‐observer variability.

Non-hyperaemic pressure ratios to guide percutaneous coronary intervention

The use of fractional flow reserve (FFR) in guiding revascularisation improves patient outcomes and has been well-established in clinical guidelines. Despite this, the uptake of FFR has been limited, likely attributable to the perceived increase in procedural time and use of hyperaemic agents that can cause patient discomfort. This has led to the development of instantaneous wave-free ratio (iFR), an alternative non-hyperaemic pressure ratio (NHPR). Since its inception, the use of iFR has been supported by an increasing body of evidence and is now guideline recommended. More recently, other commercially available NHPRs including diastolic hyperaemia-free ratio and resting full-cycle ratio have emerged. Studies have demonstrated that these indices, in addition to mean distal coronary artery pressure to mean aortic pressure ratio, are mathematically analogous (with specific nuances) to iFR. Additionally, there is increasing data demonstrating the equivalent diagnostic performance of alternative NHPRs in comparison with iFR and FFR. These NHPRs are now integral within most current pressure wire systems and are commonly available in the catheter laboratory. It is therefore key to understand the fundamental differences and evidence for NHPRs to guide appropriate clinical decision-making.

1-Year COMBO stent outcomes stratified by the PARIS bleeding prediction score: From the MASCOT registry

Background

The COMBO stent is a biodegradable-polymer sirolimus-eluting stent with endothelial progenitor cell capture technology for faster endothelialization.

Objective

We analyzed COMBO stent outcomes in relation to bleeding risk using the PARIS bleeding score.

Methods

MASCOT was an international registry of all-comers undergoing attempted COMBO stent implantation. We stratified patients as low bleeding-risk (LBR) for PARIS score ≤ 3 and intermediate-to-high (IHBR) for score > 3 based on baseline age, body mass index, anemia, current smoking, chronic kidney disease and need for triple therapy. Primary endpoint was 1-year target lesion failure (TLF), composite of cardiac death, myocardial infarction (MI) not clearly attributed to a non-target vessel or clinically-driven target lesion revascularization (TLR). Bleeding was adjudicated using the Bleeding Academic Research Consortium (BARC) definition. Dual antiplatelet therapy (DAPT) cessation was independently adjudicated.

Results

The study included 56% (n = 1270) LBR and 44% (n = 1009) IHBR patients. Incidence of 1-year TLF was higher in IHBR patients (4.1% vs. 2.6%, p = 0.047) driven by cardiac death (1.7% vs. 0.7%, p = 0.029) with similar rates of MI (1.8% vs. 1.1%, p = 0.17), TLR (1.5% vs. 1.6%, p = 0.89) and definite/ probable stent thrombosis (1.2% vs. 0.6%, p = 0.16). Incidence of 1-year major BARC 3 or 5 bleeding was significantly higher in IHBR patients (2.3% vs. 0.9%, p = 0.0094), as was the incidence of DAPT cessation (29.3% vs. 22.8%, p < 0.01), driven by physician-guided discontinuation.

Conclusions

Patients with intermediate-to-high PARIS bleeding risk in the MASCOT registry experienced greater incidence of 1-year TLF, major bleeding and DAPT cessation than LBR patients, without significant differences in stent thrombosis.

Overview of Quantitative Flow Ratio and Optical Flow Ratio in the Assessment of Intermediate Coronary Lesions

Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) improves clinical outcome compared with angiography-guided PCI. Advances in computational technology have resulted in the development of solutions, enabling fast derivation of FFR from imaging data in the catheterization laboratory. The quantitative flow ratio is currently the most validated approach to derive FFR from invasive coronary angiography, while the optical flow ratio allows faster and more automation in FFR computation from intracoronary optical coherence tomography. The use of quantitative flow ratio and optical flow ratio has the potential for swift and safe identification of lesions that require revascularization, optimization of PCI, evaluation of plaque features, and virtual planning of PCI.

Percutaneous coronary intervention: The "oculosufficient" effect and how to overcome it

Intravascular imaging and coronary physiology can improve the outcomes of percutaneous coronary intervention but are currently underutilized. Longer procedure time, higher cost, and challenges with performance and interpretation are barriers to the use of intravascular imaging and physiology. Selective application of imaging and physiology in more complex interventions, education of how to use these modalities, and reimbursement of the equipment cost could increase adoption of these techniques in everyday clinical practice.

Inter-observer differences in interpretation of coronary pressure-wire pullback data by non-expert interventional cardiologists

The physiological pattern of coronary artery disease as determined by pressure-wire (PW)-pullback is important for decision-making of revascularization and risk stratification of patients. However, it remains unclear whether inter-observer differences in interpreting PW-pullback data are subject to the expertise of physicians. This study sought to investigate the subjectivity of this assessment among non-experts. Expert interventional cardiologists classified 545 PW-pullback traces into physiologically focal or physiologically diffuse disease pattern. Defining expert-consensus as the reference standard, we evaluated ten non-expert doctors' classification performance. Observers were stratified equally by two ways: (i) years of experience as interventional cardiologists (middle-level vs. junior-level) and (ii) volume of institutions where they belonged to (high-volume center vs. low-volume center). When judged against the expert-consensus, the agreement of non-expert observers in assessing physiological pattern of disease (focal or diffuse) ranged from 69.1 to 85.0% (p for heterogeneity < 0.0001). There was no evidence for a moderating effect of years of experience; the pooled accuracy of middle-level doctors was 78.8% (95% confidential interval [CI] 72.8-84.7%) vs. 79.1% for junior-level doctors (95% CI 75.9-82.2%, p = 0.95 for difference). On the other hand, we observed a significant moderating effect of center volume. Accuracy across non-experts in high-volume centers was 82.7% (95% CI 80.3-85.1%) vs. 75.1% for low-volume centers (95% CI 71.9-78.3%, p = 0.0002 for difference). Interpretation of PW-pullback by non-expert interventional cardiologists was considerably subjective.

The year in review: advances in interventional cardiology in 2019

PURPOSE OF REVIEW

Major studies in interventional cardiology in 2019 have added substantial new evidence for pharmaco-invasive management of coronary artery disease. The review highlights the main findings of a selection of these trials and summarizes their impact on clinical practice.

RECENT FINDINGS

Recent randomized studies examining the efficacy of revascularization or medical treatment in stable ischemic heart disease (SIHD), treatment of acute coronary syndromes, emerging interventional devices, adjunctive pharmacotherapy, and intravascular imaging and physiology guidance have substantially advanced the evidenced-based knowledge in interventional cardiology.

SUMMARY

Patients with SIHD and at least moderate myocardial ischemia have similar event-free survival after an initial conservative strategy of optimal medical therapy versus an upfront invasive strategy. Quality of life and angina-free status are significantly improved with revascularization. Percutaneous coronary intervention (PCI) and coronary artery bypass grafting provide similar 5-year outcomes in patients with left main coronary artery disease and low or intermediate disease complexity. An initially conservative management is equally effective as an early invasive approach in patients with out-of-hospital cardiac arrest without ongoing ischemia. Patients with ST-segment elevation myocardial infarction and multivessel disease benefit from staged complete revascularization after primary PCI. Post-PCI, patients with atrial fibrillation requiring anticoagulation can safely and effectively be treated with P2Y12 inhibitor monotherapy without aspirin. Lastly, intravascular imaging guidance improves post-PCI outcomes, warranting increased use in clinical practice.

A randomized controlled trial of a physiology-guided percutaneous coronary intervention optimization strategy: Rationale and design of the TARGET FFR study

Post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) ≥0.90 confers an improved cardiac prognosis. There are currently limited data available to determine how often it is possible to improve an angiographically acceptable but physiologically suboptimal result. A physiology-guided optimization strategy can achieve a clinically meaningful increase in the proportion of patients achieving a final post-PCI FFR ≥0.90 compared to standard care. Following angiographically successful PCI procedures, 260 patients will be randomized (1:1) to receive either a physiology-guided incremental optimization strategy (intervention group) or blinded post-PCI coronary physiology measurements (control group). Patients undergoing successful, standard-of-care PCI for either stable angina or non-ST-segment-elevation myocardial infarction who meet the study's inclusion and exclusion criteria will be eligible for randomization. The primary endpoint is defined as the proportion of patients with a final post-PCI FFR result ≥0.90. Secondary endpoints include change from baseline in Seattle Angina Questionnaire and EQ-5D-5L scores at 3 months and the rate of target vessel failure and its components (cardiac death, myocardial infarction, stent thrombosis, unplanned rehospitalization with target vessel revascularization) at 3 months and 1 year. 260 individual patients were successfully randomized between March 2018 and November 2019. Key baseline demographics of the study population are reported within. TARGET FFR is an investigator-initiated, prospective, single-center, randomized controlled trial of an FFR-guided PCI optimization strategy. The study has completed recruitment and is now in clinical follow-up. It is anticipated that primary results will be presented in Autumn 2020. ClinicalTrials.gov Identifier: NCT03259815. [Correction added on Apr 3 2020, after first online publication: Clinical Trials identifier added.].

Physiological Assessment of Coronary Lesions in 2020

PURPOSE OF REVIEW

Physiological assessment of coronary artery disease (CAD) is an essential component of the interventional cardiology toolbox. However, despite long-term data demonstrating improved outcomes, physiology-guided percutaneous coronary intervention (PCI) remains underutilized in current practice. This review outlines the indications and technical aspects involved in evaluating coronary stenosis physiology, focusing on the latest developments in the field.

RECENT FINDINGS

Beyond fractional flow reserve (FFR), non-hyperemic pressure ratios (NHPR) that assess coronary physiology at rest without hyperemia now abound. Additional advances in other alternative FFR approaches, including non-invasive coronary CT (FFR_CT), invasive angiography (FFR_angio), and optical coherence tomography (FFR_OCT), are being realized. Artificial intelligence algorithms and robust tools that enable detailed pre-procedure "virtual" intervention are also emerging. The benefits of coronary physiological assessment to determine lesion functional significance are well established. In addition to stable CAD, coronary physiology can be especially helpful in clinical scenarios such as left main and multivessel CAD, serial lesions, non-infarct-related arteries in acute coronary syndromes, and residual ischemia post-PCI. Today, coronary physiological assessment remains an indispensable tool in the catheterization laboratory, with an exciting technological future that will further refine clinical practice and improve patient care.