Warranty period of coronary computed tomography angiography and [15O]H2O positron emission tomography in symptomatic patients

AIMS

Data on the warranty period of coronary computed tomography angiography (CTA) and combined coronary CTA/positron emission tomography (PET) are scarce. The present study aimed to determine the event-free (warranty) period after coronary CTA and the potential additional value of PET.

METHOD AND RESULTS

Patients with suspected but not previously diagnosed coronary artery disease (CAD) who underwent coronary CTA and/or [15O]H2O PET were categorized based upon coronary CTA as no CAD, non-obstructive CAD, or obstructive CAD. A hyperaemic myocardial blood flow (MBF) ≤ 2.3 mL/min/g was considered abnormal. The warranty period was defined as the time for which the cumulative event rate of death and non-fatal myocardial infarction (MI) was below 5%. Of 2575 included patients (mean age 61.4 ± 9.9 years, 41% male), 1319 (51.2%) underwent coronary CTA only and 1237 (48.0%) underwent combined coronary CTA/PET. During a median follow-up of 7.0 years 163 deaths and 68 MIs occurred. The warranty period for patients with no CAD on coronary CTA was ≥10 years, whereas patients with non-obstructive CAD had a 5-year warranty period. Patients with obstructive CAD and normal hyperaemic MBF had a 2-year longer warranty period compared to patients with obstructive CAD and abnormal MBF (3 years vs. 1 year).

CONCLUSION

As standalone imaging, the warranty period for normal coronary CTA is ≥10 years, whereas patients with non-obstructive CAD have a warranty period of 5 years. Normal PET yielded a 2-year longer warranty period in patients with obstructive CAD.

Validation of the OPEN-CLEAN Chronic Total Occlusion Percutaneous Coronary Intervention Perforation Score in a Multicenter Registry

Coronary artery perforation is one of the most common and feared complications of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). We evaluated the utility of the recently presented OPEN-CLEAN (Coronary artery bypass graft, Length of occlusion, Ejection fraction, Age, calcificatioN) perforation score in an independent multicenter CTO PCI dataset. Of the 2,270 patients who underwent CTO PCI at 7 centers, 150 (6.6%) suffered coronary artery perforation. Patients with perforations were older (69 ± 10 vs 65 ± 10, p <0.001), more likely to be women (89% vs 82%, p = 0.010), more likely to have history of previous coronary artery bypass graft (38% vs 20%, p <0.001), and unfavorable angiographic characteristics such as blunt stump (64% vs 42%, p <0.001), proximal cap ambiguity (51% vs 33%, p <0.001), and moderate-severe calcification (57% vs 43%, p = 0.001). Technical success was lower in patients with perforations (69% vs 85%, p <0.001). The area under the receiver operating characteristic curve of the OPEN-CLEAN perforation risk model was 0.74 (95% confidence interval 0.68 to 0.79), with good calibration (Hosmer-Lemeshow p = 0.72). We found that the CTO PCI perforation risk increased with higher OPEN-CLEAN scores: 3.5% (score 0 to 1), 3.1% (score 2), 5.3% (score 3), 7.1% (score 4), 11.5% (score 5), 19.8% (score 6 to 7). In conclusion, given its good performance and ease of preprocedural calculation, the OPEN-CLEAN perforation score appears to be useful for quantifying the perforation risk for patients who underwent CTO PCI.

Diabetes, Atherosclerosis, and Stenosis by AI

OBJECTIVE

This study evaluates the relationship between atherosclerotic plaque characteristics (APCs) and angiographic stenosis severity in patients with and without diabetes. Whether APCs differ based on lesion severity and diabetes status is unknown.

RESEARCH DESIGN AND METHODS

We retrospectively evaluated 303 subjects from the Computed TomogRaphic Evaluation of Atherosclerotic Determinants of Myocardial IsChEmia (CREDENCE) trial referred for invasive coronary angiography with coronary computed tomographic angiography (CCTA) and classified lesions as obstructive (≥50% stenosed) or nonobstructive using blinded core laboratory analysis of quantitative coronary angiography. CCTA quantified APCs, including plaque volume (PV), calcified plaque (CP), noncalcified plaque (NCP), low-density NCP (LD-NCP), lesion length, positive remodeling (PR), high-risk plaque (HRP), and percentage of atheroma volume (PAV; PV normalized for vessel volume). The relationship between APCs, stenosis severity, and diabetes status was assessed.

RESULTS

Among the 303 patients, 95 (31.4%) had diabetes. There were 117 lesions in the cohort with diabetes, 58.1% of which were obstructive. Patients with diabetes had greater plaque burden (P = 0.004). Patients with diabetes and nonobstructive disease had greater PV (P = 0.02), PAV (P = 0.02), NCP (P = 0.03), PAV NCP (P = 0.02), diseased vessels (P = 0.03), and maximum stenosis (P = 0.02) than patients without diabetes with nonobstructive disease. APCs were similar between patients with diabetes with nonobstructive disease and patients without diabetes with obstructive disease. Diabetes status did not affect HRP or PR. Patients with diabetes had similar APCs in obstructive and nonobstructive lesions.

CONCLUSIONS

Patients with diabetes and nonobstructive stenosis had an association to similar APCs as patients without diabetes who had obstructive stenosis. Among patients with nonobstructive disease, patients with diabetes had more total PV and NCP.

Abnormal physiological findings after FFR-based revascularisation deferral are associated with worse prognosis in women

The prognostic value of abnormal resting Pd/Pa and coronary flow reserve (CFR) after fractional flow reserve (FFR)-guided revascularisation deferral according to sex remains unknown. From the ILIAS Registry composed of 20 hospitals globally from 7 countries, patients with deferred lesions following FFR assessment (FFR > 0.8) were included. (NCT04485234) The primary clinical endpoint was target vessel failure (TVF) at 2-years follow-up. We included 1392 patients with 1759 vessels (n = 564 women, 31.9%). Although resting Pd/Pa was similar between the sexes (p = 0.116), women had lower CFR than men (2.5 [2.0-3.2] vs. 2.7 [2.1-3.5]; p = 0.004). During a 2-year follow-up period, TVF events occurred in 56 vessels (3.2%). The risk of 2-year TVF was significantly higher in women with low versus high resting Pd/Pa (HR: 9.79; p < 0.001), whereas this trend was not seen in men. (Sex: P-value for interaction = 0.022) Furthermore, resting Pd/Pa provided an incremental prognostic value for 2-year TVF over CFR assessment only in women. After FFR-based revascularisation deferral, low resting Pd/Pa is associated with higher risk of TVF in women, but not in men. The predictive value of Pd/Pa increases when stratified according to CFR values, with significantly high TVF rates in women in whom both indices are concordantly abnormal.Clinical Trial Registration: Inclusive Invasive Physiological Assessment in Angina Syndromes Registry (ILIAS Registry), NCT04485234.

External validation of the PROGRESS-CTO perforation risk score: Individual patient data pooled analysis of three registries

BACKGROUND

Coronary artery perforation is one of the most feared and common complications of chronic total occlusion (CTO) percutaneous coronary intervention (PCI).

METHODS

To assess the usefulness of the recently developed PROGRESS-CTO (NCT02061436) perforation risk score in independent cohorts. Individual patient-level data pooled analysis of three registries was performed.

RESULTS

Of the 4566 patients who underwent CTO PCI at 25 centers, 196 (4.2%) had coronary artery perforation. Patients with perforations were older (69 ± 10 vs. 65 ± 10, p < 0.001), more likely to be women (19% vs. 13%, p = 0.009), more likely to have a history of prior coronary artery bypass graft (34% vs. 20%, p < 0.001), and unfavorable angiographic characteristics such as blunt stump (62% vs. 48%, p < 0.001), proximal cap ambiguity (52% vs. 34%, p < 0.001), and moderate-severe calcification (60% vs. 49%, p = 0.002). Technical success was lower in patients with perforations (73% vs. 88%, p < 0.001). The area under the receiver operating characteristic curve of the PROGRESS-CTO perforation risk model was 0.76 (95% confidence interval [CI], 0.72-0.79), with good calibration (Hosmer-Lemeshow p = 0.97). We found that the CTO PCI perforation risk increased with higher PROGRESS-CTO perforation scores: 0.3% (score 0), 2.3% (score 1), 3.1% (score 2), 5.5% (score 3), 7.5% (score 4), 14.6% (score 5).

CONCLUSION

Given the good discriminative performance, calibration, and the ease of calculation, the PROGRESS-CTO perforation score may facilitate assessment of the risk of perforation in patients undergoing CTO PCI.

Combined use of hyperemic and non-hyperemic pressure ratios for revascularization decision-making: From the ILIAS registry

OBJECTIVE

The aim of this study is to evaluate the diagnostic and prognostic value of non-hyperaemic Pd/Pa and to determine its additional value when combined with the gold standard hyperaemic pressure ratio (FFR) to guide revascularization.

METHODS

In a large, multi-center, retrospective registry, we included a total of 2141 patients with a clinical indication for coronary angiography providing physiological data in 2726 vessels. A classification was made based on the FFR (cut-off value: 0.80) and non-hyperaemic Pd/Pa (cut-off value: 0.92) values and the primary outcome was target-vessel failure (TVF) at 5-year follow-up.

RESULTS

Mean age was 63 ± 10.0 and 75% of the study population were men. Regression analysis showed an overall good correlation between FFR and non-hyperaemic Pd/Pa (r = 0.73, p < 0.005) and discordance was present in 17% of the vessels. Resting Pd/Pa was independently associated with TVF at 5-year follow-up (HR 0.08, 95%CI: 0.02-0.27; p < 0.005). The risk for TVF was the lowest in vessles with concordant normal pressure ratio's, with the highest risk in vessels with any abnormal pressure ratio in which revascularization was deferred. In these vessels, there was no difference in risk for TVF between the discordant and concordant abnormal values.

CONCLUSION

Abnormal pressure ratios in both non-hyperemic and hyperemic conditions portend important prognostic value. Combined application of FFR and non-hyperemic Pd/Pa efficiently identifies those vessels with concordant normal resting and hyperemic pressure ratios of which long-term clinical outcomes are excellent. These data lead to hypothesize that the decision to defer revascularization should potentially be based on combined non-hyperemic and hyperemic pressure ratios.

CLINICAL TRIAL REGISTRATION

Inclusive Invasive Physiological Assessment in Angina Syndromes Registry (ILIAS Registry), NCT04485234.

Pre-procedural planning of coronary revascularization by cardiac computed tomography: An expert consensus document of the Society of Cardiovascular Computed Tomography

Coronary CT angiography (CCTA) demonstrated high diagnostic accuracy for detecting coronary artery disease (CAD) and a key role in the management of patients with low-to-intermediate pretest likelihood of CAD. However, the clinical information provided by this noninvasive method is still regarded insufficient in patients with diffuse and complex CAD and for planning percutaneous coronary intervention (PCI) and surgical revascularization procedures. On the other hand, technology advancements have recently shown to improve CCTA diagnostic accuracy in patients with diffuse and calcific stenoses. Moreover, stress CT myocardial perfusion imaging (CT-MPI) and fractional flow reserve derived from CCTA (CT-FFR) have been introduced in clinical practice as new tools for evaluating the functional relevance of coronary stenoses, with the possibility to overcome the main CCTA drawback, i.e. anatomical assessment only. The potential value of CCTA to plan and guide interventional procedures lies in the wide range of information it can provide: a) detailed evaluation of plaque extension, volume and composition; b) prediction of procedural success of CTO PCI using scores derived from CCTA; c) identification of coronary lesions requiring additional techniques (e.g., atherectomy and lithotripsy) to improve stent implantation success by assessing calcium score and calcific plaque distribution; d) assessment of CCTA-derived Syntax Score and Syntax Score II, which allows to select the mode of revascularization (PCI or CABG) in patients with complex and multivessel CAD. The aim of this Consensus Document is to review and discuss the available data supporting the role of CCTA, CT-FFR and stress CT-MPI in the preprocedural and possibly intraprocedural planning and guidance of myocardial revascularization interventions.

Prophylactic Impella CP versus VA-ECMO in Patients Undergoing Complex High-Risk Indicated PCI

OBJECTIVES

To compare two different forms of mechanical circulatory support (MCS) in patients with complex high-risk indicated PCI (CHIP): the Impella CP system and veno-arterial extracorporeal membrane oxygenation (VA-ECMO).

BACKGROUND

To prevent hemodynamic instability in CHIP, various MCS systems are available. However, comparable data on different forms of MCS are not at hand.

METHODS

In this multicenter observational study, we retrospectively evaluated all CHIP procedures with the support of an Impella CP or VA-ECMO, who were declined surgery by the heart team. Major adverse cardiac events (MACE), mortality at discharge, and 30-day mortality were evaluated.

RESULTS

A total of 41 patients were included, of which 27 patients were supported with Impella CP and 14 patients with VA-ECMO. Baseline characteristics were well-balanced in both groups. No significant difference in periprocedural hemodynamic instability was observed between both groups (3.7% vs. 14.3%; p = 0.22). The composite outcome of MACE showed no significant difference (30.7% vs. 21.4%; p = 0.59). Bleeding complications were higher in the Impella CP group, but showed no significant difference (22.2% vs. 7.1%; p = 0.22) and occurred more at the non-Impella access site. In-hospital mortality was 7.4% in the Impella CP group versus 14.3% in the VA-ECMO group and showed no significant difference (p = 0.48). 30-Day mortality showed no significant difference (7.4% vs. 21.4%; p = 0.09).

CONCLUSIONS

In patients with CHIP, there were no significant differences in hemodynamic instability and overall MACE between VA-ECMO or Impella CP device as mechanical circulatory support. Based on this study, the choice of either VA-ECMO or Impella CP does not alter the outcome.

A Systematic Review and Meta-Analysis of Clinical Outcomes of Patients Undergoing Chronic Total Occlusion Percutaneous Coronary Intervention

OBJECTIVES

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) can improve patient symptoms, but it remains controversial whether it impacts subsequent clinical outcomes.

METHODS

In this systematic review and meta-analysis, we queried PubMed, ScienceDirect, Cochrane Library, Web of Science, and Embase databases (last search: September 15, 2021). We investigated the impact of CTO-PCI on clinical events including all-cause mortality, cardiovascular death, myocardial infarction (MI), major adverse cardiovascular event (MACE), stroke, subsequent coronary artery bypass surgery, target-vessel revascularization, and heart failure hospitalizations. Pooled analysis was performed using a random-effects model.

RESULTS

A total of 58 publications with 54,540 patients were included in this analysis, of which 33 were observational studies of successful vs failed CTO-PCI, 19 were observational studies of CTO-PCI vs no CTO-PCI, and 6 were randomized controlled trials (RCTs). In observational studies, but not RCTs, CTO-PCI was associated with better clinical outcomes. Odds ratios (ORs) and 95% confidence intervals (CIs) for all-cause mortality, MACE, and MI were 0.52 (95% CI, 0.42-0.64), 0.46 (95% CI, 0.37-0.58), 0.66 (95% CI, 0.50-0.86), respectively for successful vs failed CTO-PCI studies; 0.38 (95% CI, 0.31-0.45), 0.57 (95% CI, 0.42-0.78), 0.65 (95% CI, 0.42-0.99), respectively, for observational studies of CTO-PCI vs no CTO-PCI; 0.72 (95% CI, 0.39-1.32), 0.69 (95% CI, 0.38-1.25), and 1.04 (95% CI, 0.46-2.37), respectively for RCTs.

CONCLUSIONS

CTO-PCI is associated with better subsequent clinical outcomes in observational studies but not in RCTs. Appropriately powered RCTs are needed to conclusively determine the impact of CTO-PCI on clinical outcomes.

Pre-procedural planning of coronary revascularization by cardiac computed tomography: An expert consensus document of the Society of Cardiovascular Computed Tomography

Coronary CT angiography (CCTA) demonstrated high diagnostic accuracy for detecting coronary artery disease (CAD) and a key role in the management of patients with low-to-intermediate pretest likelihood of CAD. However, the clinical information provided by this noninvasive method is still regarded insufficient in patients with diffuse and complex CAD and for planning percutaneous coronary intervention (PCI) and surgical revascularization procedures. On the other hand, technology advancements have recently shown to improve CCTA diagnostic accuracy in patients with diffuse and calcific stenoses. Moreover, stress CT myocardial perfusion imaging (CT-MPI) and fractional flow reserve derived from CCTA (CT-FFR) have been introduced in clinical practice as new tools for evaluating the functional relevance of coronary stenoses, with the possibility to overcome the main CCTA drawback, i.e. anatomical assessment only. The potential value of CCTA to plan and guide interventional procedures lies in the wide range of information it can provide: a) detailed evaluation of plaque extension, volume and composition; b) prediction of procedural success of CTO PCI using scores derived from CCTA; c) identification of coronary lesions requiring additional techniques (e.g., atherectomy and lithotripsy) to improve stent implantation success by assessing calcium score and calcific plaque distribution; d) assessment of CCTA-derived Syntax Score and Syntax Score II, which allows to select the mode of revascularization (PCI or CABG) in patients with complex and multivessel CAD. The aim of this Consensus Document is to review and discuss the available data supporting the role of CCTA, CT-FFR and stress CT-MPI in the preprocedural and possibly intraprocedural planning and guidance of myocardial revascularization interventions.

Prognostic value of structural and functional coronary microvascular dysfunction in patients with non-obstructive coronary artery disease; from the multicentre international ILIAS registry

BACKGROUND

Coronary microvascular dysfunction (CMD) is an important contributor to angina syndromes. Recently, two distinct endotypes were identified using combined assessment of coronary flow reserve (CFR) and minimal microvascular resistance (MR), termed structural and functional CMD.

AIMS

We aimed to assess the relevance of the combined assessment of CFR and MR in patients with angina and no obstructive coronary arteries.

METHODS

Patients with chronic coronary syndromes (CCS) and non-obstructive coronary artery disease (fractional flow reserve [FFR] ≥0.80) were selected (N=1,102). Functional CMD was defined as abnormal CFR in combination with normal MR and structural CMD as abnormal CFR with abnormal MR. Clinical endpoints were the incidence of major adverse cardiac events (MACE) and target vessel failure (TVF) at 5-year follow-up.

RESULTS

Abnormal CFR was associated with an increased risk of MACE and TVF at 5-year follow-up. Microvascular resistance parameters were not associated with MACE or TVF at 5-year follow-up. The risk of MACE and TVF at 5-year follow-up was similarly increased for patients with structural or functional CMD compared with patients with normal microvascular function. There were no differences between both endotypes (p=0.88 for MACE, and p=0.55 for TVF).

CONCLUSIONS

Coronary microvascular dysfunction, identified by an impaired CFR, was unequivocally associated with increased MACE and TVF rates over a 5-year follow-up period. In contrast, impaired MR was not associated with 5-year adverse clinical events. Moreover, there was no significant difference in the risk of MACE and TVF between a low CFR accompanied by pathologically increased MR (structural CMD) or not (functional CMD).

CLINICALTRIALS

gov: NCT04485234.

Concordant low and discordant fractional flow reserve and instantaneous wave-free ratio measurements are associated with reduced myocardial perfusion

Background

In patients undergoing invasive coronary angiography with functional lesion assessment, both fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) measurements can be used to guide coronary revascularization decision-making. The hemodynamic significance of lesions with discordant FFR and iFR measurements is debated.

Purpose

This study compared quantitative myocardial perfusion indices as assessed by [15O]H2O positron emission tomography (PET) perfusion imaging in vessels with concordant high, discordant and concordant low FFR/iFR measurements

Methods

This post-hoc analysis of the PACIFIC I and II studies included 198 patients suspected of obstructive coronary artery disease who had undergone [15O]H2O PET imaging and subsequent FFR/iFR interrogation in 468 vessels. Resting myocardial blood flow (MBF), hyperemic MBF and coronary flow reserve (CFR) were compared between 4 vessel subgroups: FFR+/iFR+ (n=79), FFR−/iFR+ (n=22), FFR+/iFR− (n=22) and FFR−/iFR− (n=345).

Results

Discordant FFR/iFR indices were found in 44 (9%) vessels. Hyperemic MBF was significantly lower for vessels with FFR+/iFR+ (2.09±0.67 mL min–1 g–1), FFR−/iFR+ (2.41±0.80 mL min–1 g–1) and FFR+/iFR− (2.40±0.69 mL min–1 g–1) compared to FFR−/iFR− vessels (2.91±0.84 mL min–1 g–1) (p&lt;0.01, p=0.03 and p&lt;0.01, respectively). Hyperemic MBF did not differ between vessels with FFR+/iFR+ compared to FFR−/iFR+ (p=0.38) and FFR+/iFR− (p=0.35) vessels. In addition, resting MBF was lower and CFR did not differ in the FFR+/iFR− versus the FFR−/iFR− group (resting MBF: 0.80±0.16 mL min–1 g–1 vs. 0.90±0.24 mL min–1 g–1, p=0.03 and CFR: 3.05±0.84 vs. 3.35±1.07, p=0.56). Finally, CFR was similar in FFR+/iFR+ and FFR−/iFR+ vessels (2.37±0.76 vs. 2.64±0.84, p=0.92).

Conclusions

We found lower baseline flow and similar flow reserve in FFR+/iFR− compared to FFR−/iFR− vessels. Importantly, [15O]H2O PET imaging demonstrated reduced hyperemic MBF in vessels with concordant low and discordant FFR and iFR measurements.

Funding Acknowledgement

Type of funding sources: None.

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

Background

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Funding Acknowledgement

Type of funding sources: None.

Predicting success of the retrograde approach in percutaneous coronary intervention of chronic total coronary occlusions as guided by collateral grading systems

Background

Retrograde chronic total coronary occlusion (CTO) percutaneous coronary intervention (PCI) requires selection of appropriate interventional collaterals. At present, utilization of the Rentrop and Werner grading systems are encouraged to assess the collateral channels (CCs) prior to attempted guidewire (GW) crossing [1]. The J-Channel score was recently introduced to predict CC GW crossing difficulty, yet data on its applicability is lacking [2].

Purpose

To investigate the predictive ability of the J-Channel score for CC GW crossing success and technical CTO-PCI success compared to the Rentrop and Werner grading systems.

Methods

A total of 262 patients who underwent single-vessel retrograde CTO-PCI were prospectively recruited in a single-center registry. The J-Channel score, Rentrop and Werner grade were assessed by invasive coronary angiography. Crossing of CCs was considered successful if the GW reached the distal cap of the CTO body. Technical CTO-PCI success was defined as Thrombolysis in Myocardial Infarction flow grade 3 and residual stenosis &lt;30%.

Results

Mean J-Channel score was found at 1.9±1.2. Median Rentrop and Werner grade were 3 [IQR 2–3] and 1 [IQR 1–2]. Technical CTO-PCI success was 90%. In 211 (81%) cases, CC GW crossing was successful. Receiver operating characteristics analysis showed comparable discriminatory capacity for Rentrop and Werner grade (AUC 0.67 and 0.65, p=0.611), whereas the predictive ability of the J-Channel score (AUC 0.74) was superior to the Werner grade (p&lt;0.001). A high J-Channel score was inversely associated with CC GW crossing success (p&lt;0.001). For technical CTO-PCI success, overall performance of all grading systems weakened, wherein Rentrop grade was numerically highest, followed by the J-Channel score and Werner grade (AUC 0.69, 0.67, and 0.58, respectively). Notably, a high Rentrop grade was associated with increased CC GW crossing and technical CTO-PCI success (p&lt;0.001).

Conclusions

In retrograde CTO-PCI, there is limited incremental value of the J-Channel score, Rentrop classification and Werner grade in predicting technical CTO-PCI success. However, their application might aid in strategic collateral channel selection prior to attempted guidewire crossing.

Funding Acknowledgement

Type of funding sources: None.

QFR vs. perfusion imaging to predict abnormal FFR in patients with prior coronary artery disease

Background

In patients with suspected obstructive coronary artery disease (CAD) and a high pre-test probability, myocardial perfusion imaging (MPI) or referral for invasive coronary angiography (ICA) are viable diagnostic strategies. The present study compared the diagnostic performance of quantitative flow ratio (QFR) and MPI by single-photon emission computed tomography (SPECT), positron emission tomography (PET), and cardiac magnetic resonance imaging (CMR).

Methods

In this PACIFIC-II substudy, 189 patients with prior MI/PCI who were suspected of having symptoms related to myocardial ischemia and underwent SPECT, PET, and CMR before ICA were evaluated for inclusion. ICA was obtained with (109 patients) and without (80 patients) adherence to a QFR acquisition protocol. All major coronary arteries were interrogated by FFR, except for vessels with a subtotal/total occlusion. An FFR ≤0.80 was used to define significant epicardial CAD. QFR analyses (v2.0) were performed based on ICA by a corelab in vascular territories (N=487) in which FFR was obtained. MPI modalities were assessed for presence of ischemia by corelabs, uninterpretable scans were omitted from the diagnostic comparison analyses.

Results

QFR analysis success rate was higher (81%) among vessels acquired using the QFR acquisition protocol compared to vessels obtained without the protocol (52%, p&lt;0.001). Overall, a QFR result was available in 334 (69%) vessels. Among these vessels, QFR had a higher sensitivity (72%) and accuracy (84%) compared to SPECT (46%, p=0.001 and 66%, p&lt;0.001), PET (58%, p=0.032 and 65%, p&lt;0.001), and CMR (33%, p&lt;0.001 and 72%, p&lt;0.001). Whereas specificity of QFR (87%) was similar to CMR (83%, p=0.123) but higher than that of SPECT (71%, p&lt;0.001) and PET (67%, p&lt;0.001). Lastly, QFR exhibited a higher area under the receiver operating characteristic curve (0.89) than SPECT (0.57, p&lt;0.001), PET (0.66, p&lt;0.001), and CMR (0.60, p&lt;0.001).

Conclusions

Provided QFR was analyzable (69% of the vessels), QFR correlated better with FFR (both as measures of epicardial CAD) than MPI as reflected in the diagnostic performance measures for detecting vessels-specific significant epicardial CAD as defined by FFR.

Funding Acknowledgement

Type of funding sources: None.

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

Background

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

Purpose

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

Methods

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

Results

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

Conclusions

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

Funding Acknowledgement

Type of funding sources: None.

Machine Learning From Quantitative Coronary Computed Tomography Angiography Predicts Fractional Flow Reserve-Defined Ischemia and Impaired Myocardial Blood Flow

BACKGROUND

A pathophysiological interplay exists between plaque morphology and coronary physiology. Machine learning (ML) is increasingly being applied to coronary computed tomography angiography (CCTA) for cardiovascular risk stratification. We sought to assess the performance of a ML score integrating CCTA-based quantitative plaque features for predicting vessel-specific ischemia by invasive fractional flow reserve (FFR) and impaired myocardial blood flow (MBF) by positron emission tomography (PET).

METHODS

This post-hoc analysis of the PACIFIC trial (Prospective Comparison of Cardiac Positron Emission Tomography/Computed Tomography [CT]' Single Photon Emission Computed Tomography/CT Perfusion Imaging and CT Coronary Angiography with Invasive Coronary Angiography) included 208 patients with suspected coronary artery disease who prospectively underwent CCTA' [15O]H2O PET, and invasive FFR. Plaque quantification from CCTA was performed using semiautomated software. An ML algorithm trained on the prospective NXT trial (484 vessels) was used to develop a ML score for the prediction of ischemia (FFR≤0.80), which was then evaluated in 581 vessels from the PACIFIC trial. Thereafter, the ML score was applied for predicting impaired hyperemic MBF (≤2.30 mL/min per g) from corresponding PET scans. The performance of the ML score was compared with CCTA reads and noninvasive FFR derived from CCTA (FFRCT).

RESULTS

One hundred thirty-nine (23.9%) vessels had FFR-defined ischemia, and 195 (33.6%) vessels had impaired hyperemic MBF. For the prediction of FFR-defined ischemia, the ML score yielded an area under the receiver-operating characteristic curve of 0.92, which was significantly higher than that of visual stenosis grade (0.84; P<0.001) and comparable with that of FFRCT (0.93; P=0.34). Quantitative percent diameter stenosis and low-density noncalcified plaque volume had the greatest ML feature importance for predicting FFR-defined ischemia. When applied for impaired MBF prediction, the ML score exhibited an area under the receiver-operating characteristic curve of 0.80; significantly higher than visual stenosis grade (area under the receiver-operating characteristic curve 0.74; P=0.02) and comparable with FFRCT (area under the receiver-operating characteristic curve 0.77; P=0.16).

CONCLUSIONS

An externally validated ML score integrating CCTA-based quantitative plaque features accurately predicts FFR-defined ischemia and impaired MBF by PET, performing superiorly to standard CCTA stenosis evaluation and comparably to FFRCT.

Complex High-Risk Indicated Percutaneous Coronary Intervention With Prophylactic Use of the Impella CP Ventricular Assist Device

OBJECTIVES

Patients with complex coronary artery disease, concomitant cardiac disease, and multiple comorbidities are addressed as complex higher-risk indicated patients (CHIPs). Selecting a revascularization strategy in this population remains challenging. If coronary artery bypass grafting is deemed high risk or patients are considered inoperable, high-risk percutaneous coronary intervention (PCI) with the support of the Impella CP ventricular assist device (Abiomed) may be an attractive alternative.

METHODS

In this retrospective, multicenter study, we included consecutive patients undergoing Impella CP-facilitated complex high-risk PCI. All patients were discussed by the heart team and were declined for surgery. Additionally, periprocedural mechanical circulatory support was deemed necessary. We collected demographic, clinical, and procedural characteristics. Major adverse cardiac event (MACE) and mortality rates up to 30 days were evaluated.

RESULTS

A total of 27 patients (median age, 73 ± 9.7 years; 74.1% men) were included in our study. The median SYNTAX score was 32 (range, 8-57) and EuroSCORE was 7.25% (range, 1.33-49.66; ± 12.76%). Periprocedural hemodynamic instability was observed in 1 patient (3.7%). In-hospital combined with 30-day mortality was 7.4% (2/27). No repeat revascularization was necessary. MACE was observed in 10 patients (37.0%). Six patients (22.2%) had a major bleeding complication, of which 2 were related to Impella access site. Median Impella run time was 1.22 hours and there was no significant decrease in kidney function. Median admission time after PCI was 3 days (range, 1-23; ± 4.76).

CONCLUSIONS

The Impella CP system showed good feasibility and provided adequate hemodynamic support during high-risk PCI in this CHIP population.