Optical Coherence Tomography-Based Functional Stenosis Assessment: FUSION-A Prospective Multicenter Trial.

BACKGROUND: Intravascular imaging and intracoronary physiology may both be used to guide and optimize percutaneous coronary intervention; however, they are rarely used together. The virtual flow reserve (VFR) is an optical coherence tomography (OCT)-based model of fractional flow reserve (FFR) facilitating the assessment of the physiological significance of coronary lesions. We aimed to validate the VFR assessment of intermediate coronary artery stenoses. METHODS: FUSION (Validation of OCT-Based Functional Diagnosis of Coronary Stenosis) was a multicenter, prospective, observational study comparing OCT-derived VFR to invasive FFR. VFR was mathematically derived from a lumped parameter flow model based on 3-dimensional lumen morphology. Patients undergoing coronary angiography with intermediate angiographic stenosis (40%-90%) requiring physiological assessment were enrolled. Investigational sites were blinded to the VFR analysis, and all OCT and FFR data were reviewed by an independent core laboratory. The coprimary end points were the sensitivity and specificity of VFR against FFR as the reference standard, each of which was tested against prespecified performance goals. RESULTS: After core laboratory review, 266 vessels in 224 patients from 25 US centers were included in the analysis. The mean angiographic diameter stenosis was 65.5%±14.9%, and the mean FFR was 0.83±0.11. Overall accuracy, sensitivity, and specificity of VFR versus FFR using a binary cutoff point of 0.80 were 82.0%, 80.4%, and 82.9%, respectively. The 97.5% lower confidence bound met the prespecified performance goal for sensitivity (71.6% versus 70%; P=0.01) and specificity (76.6% versus 75%; P=0.01). The area under the curve was 0.88 (95% CI, 0.84-0.92; P<0.0001). CONCLUSIONS: OCT-derived VFR demonstrates high sensitivity and specificity for predicting invasive FFR. Integrating high-resolution intravascular imaging with imaging-derived physiology may provide synergistic benefits as an adjunct to percutaneous coronary intervention. REGISTRATION: URL: https://clinicaltrials.gov; Unique identifier: NCT04356027.

1-Year Outcomes of Blinded Physiological Assessment of Residual Ischemia After Successful PCI: DEFINE PCI Trial.

OBJECTIVES: The aim of this study was to identify the post-percutaneous coronary intervention (PCI) target value of instantaneous wave-free ratio (iFR) that would best discriminate clinical events at 1 year in the DEFINE PCI (Physiologic Assessment of Coronary Stenosis Following PCI) study. BACKGROUND: The impact of residual ischemia detected by iFR post-PCI on clinical and symptom-related outcomes is unknown. METHODS: Blinded iFR pull back was performed after successful stent implantation in 500 patients. The primary endpoint was the rate of residual ischemia, defined as iFR ≤0.89, after operator-assessed angiographically successful PCI. Secondary endpoints included clinical events at 1 year and change in Seattle Angina Questionnaire angina frequency (SAQ-AF) score during follow-up. RESULTS: As reported, 24.0% of patients had residual ischemia (iFR ≤0.89) after successful PCI, with 81.6% of cases attributable to angiographically inapparent focal lesions. Post-PCI iFR ≥0.95 (present in 182 cases [39%]) was associated with a significant reduction in the composite of cardiac death, spontaneous myocardial infarction, or clinically driven target vessel revascularization compared with post-PCI iFR <0.95 (1.8% vs 5.7%; P = 0.04). Baseline SAQ-AF score was 73.3 ± 22.8. For highly symptomatic patients (baseline SAQ-AF score ≤60), SAQ-AF score increased by ≥10 points more frequently in patients with versus without post-PCI iFR ≥0.95 (100.0% vs 88.5%; P = 0.01). CONCLUSIONS: In DEFINE PCI, despite angiographically successful PCI, highly symptomatic patients at baseline without residual ischemia by post-PCI iFR had greater reductions in anginal symptoms at 1 year compared with patients with residual ischemia. Achieving post-PCI iFR ≥0.95 was also associated with improved 1-year event-free survival. (Physiologic Assessment of Coronary Stenosis Following PCI [DEFINE PCI]; NCT03084367).

Vessel fractional flow reserve (vFFR) for the assessment of stenosis severity: the FAST II study.

BACKGROUND: Fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) is superior to angiography-guided PCI. The clinical uptake of FFR has been limited, however, by the need to advance a wire in the coronary artery, the additional time required and the need for hyperaemic agents which can cause patient discomfort. FFR derived from routine coronary angiography eliminates these issues. AIMS: The aim of this study was to assess the diagnostic performance and accuracy of three-dimensional quantitative coronary angiography (3D-QCA)-based vessel FFR (vFFR) compared to pressure wire-based FFR (≤0.80). METHODS: The FAST II (Fast Assessment of STenosis severity) study was a prospective observational multicentre study designed to evaluate the diagnostic accuracy of vFFR compared to the reference standard (pressure wire-based FFR ≤0.80). A total of 334 patients from six centres were enrolled. Both site-determined and blinded independent core lab vFFR measurements were compared to FFR. RESULTS: The core lab vFFR was 0.83±0.09 and pressure wire-based FFR 0.83±0.08. A good correlation was found between core lab vFFR and pressure wire-based FFR (R=0.74; p<0.001; mean bias 0.0029±0.0642). vFFR had an excellent diagnostic accuracy in identifying lesions with an invasive wire-based FFR ≤0.80 (area under the curve [AUC] 0.93; 95% confidence interval [CI]: 0.90-0.96; p<0.001). Positive predictive value, negative predictive value, diagnostic accuracy, sensitivity and specificity of vFFR were 90%, 90%, 90%, 81% and 95%, respectively. CONCLUSIONS: 3D-QCA-based vFFR has excellent diagnostic performance to detect FFR ≤0.80. The study was registered on clinicaltrials.gov under identifier NCT03791320.

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.

Blinded Physiological Assessment of Residual Ischemia After Successful Angiographic Percutaneous Coronary Intervention: The DEFINE PCI Study.

OBJECTIVES: This study sought to evaluate the incidence and causes of an abnormal instantaneous wave-free ratio (iFR) after angiographically successful percutaneous coronary intervention (PCI). BACKGROUND: Impaired coronary physiology as assessed by fractional flow reserve is present in some patients after PCI and is prognostically relevant. METHODS: DEFINE PCI (Physiologic Assessment of Coronary Stenosis Following PCI) was a multicenter, prospective, observational study in which a blinded iFR pull back was performed after angiographically successful PCI in 562 vessels in 500 patients. Inclusion criteria were angina with either multivessel or multilesion coronary artery disease with an abnormal baseline iFR. The primary endpoint of the study was the rate of residual ischemia after operator-assessed angiographically successful PCI, defined as an iFR <0.90. The causes of impaired iFR were categorized as stent related, untreated proximal or distal focal stenosis, or diffuse atherosclerosis. RESULTS: An average of 1.1 vessels per patient had abnormal baseline iFRs, with a mean value of 0.69 ± 0.22, which improved to 0.93 ± 0.07 post-PCI. Residual ischemia after angiographically successful PCI was present in 112 patients (24.0%), with a mean iFR in that population of 0.84 ± 0.06 (range 0.60 to 0.89). Among patients with impaired post-PCI iFRs, 81.6% had untreated focal stenoses that were angiographically inapparent, and 18.4% had diffuse disease. Among the focal lesions, 38.4% were located within the stent segment, while 31.5% were proximal and 30.1% were distal to the stent. Post-PCI vessel angiographic diameter stenosis was not a predictor of impaired post-procedural iFR. CONCLUSIONS: Blinded post-PCI physiological assessment detected residual ischemia in nearly 1 in 4 patients after coronary stenting despite an operator-determined angiographically successful result. Most cases of residual ischemia were due to inapparent focal lesions potentially amenable to treatment with additional PCI. (Physiologic Assessment of Coronary Stenosis Following PCI [DEFINE PCI]; NCT03084367).

Preoperative Noncoronary Cardiovascular Assessment and Management of Kidney Transplant Candidates.

The pretransplant risk assessment for patients with ESKD who are undergoing evaluation for kidney transplant is complex and multifaceted. When considering cardiovascular disease in particular, many factors should be considered. Given the increasing incidence of kidney transplantation and the growing body of evidence addressing ESKD-specific cardiovascular risk profiles, there is an important need for a consolidated, evidence-based model that considers the unique cardiovascular challenges that these patients face. Cardiovascular physiology is altered in these patients by abrupt shifts in volume status, altered calcium-phosphate metabolism, high-output states (in the setting of arteriovenous fistulization), and adverse geometric and electrical remodeling, to name a few. Here, we present a contemporary review by addressing cardiomyopathy/heart failure, pulmonary hypertension, valvular dysfunction, and arrhythmia/sudden cardiac death within the ESKD population.

Intravascular Ultrasound Assessment of In-Stent Restenosis in Saphenous Vein Grafts.

Outcomes after percutaneous coronary interventions (PCI) in saphenous vein grafts (SVG) are inferior compared with native coronary arteries, but the mechanisms of SVG in-stent restenosis (ISR) have not been well-described. Thus, we aimed to evaluate the patterns of SVG ISR using intravascular ultrasound (IVUS) in 54 SVG ISR lesions. Stent underexpansion was defined as minimum stent area (MSA) <5 mm2. The time from stent implantation to presentation with ISR (9 BMS, 18 first-generation DES, and 27 second-generation DES) was 3.7 ± 3.0 years. IVUS-defined ISR patterns were categorized as mechanical (33%) or biological (67%). Mechanical patterns comprised 10 cases of stent underexpansion (MSA = 4.2 ± 0.9 mm2), 6 stent fractures or deformations, and 2 uncovered aorto-anastomotic lesions. Biological patterns comprised 19 cases of neoatherosclerosis, 13 excessive neointimal hyperplasia (NIH, 65 ± 11%), and 4 thrombi. Compared with biological patterns of ISR, mechanical patterns were more frequently located at the SVG anastomosis (72% vs 39%, p = 0.04) and at the SVG hinge motion site (55% vs 21%, p = 0.02). Although patients with mechanical patterns of ISR presented earlier than those with biological patterns (2.3 vs 4.4 years, p = 0.009), 61% of them were diagnosed >1 year after stent implantation. In conclusion, SVG ISR is dominated by biological patterns including neoatherosclerosis. Mechanical patterns of SVG ISR are associated with earlier presentation and location at graft anastomosis or hinge motion site.

Virtual Functional Assessment of Coronary Stenoses Using Intravascular Ultrasound Imaging: A Proof-of-Concept Pilot Study.

AIMS: We aimed to investigate the performance of virtual functional assessment of coronary stenoses using intravascular ultrasound (IVUS)-based three-dimensional (3D) coronary artery reconstruction against the invasively measured fractional flow reserve (FFR). METHODS AND RESULTS: Twenty-two (22) patients with either typical symptoms of stable angina or a positive stress test, who underwent IVUS and FFR, were included in this study. Five (5) patients presented FFR values lower than the 0.80 threshold, indicating ischaemia. IVUS-based 3D reconstruction and blood flow simulation were performed and the virtual functional assessment index (vFAI) was calculated. A strong correlation between IVUS-based vFAI and FFR was observed (Spearman correlation coefficient [rs]=0.88, p<0.0001). There was a small overestimation of the FFR by the IVUS-based vFAI (mean difference=0.0196±0.037; p=0.023 for difference from zero). All cases with haemodynamically significant stenoses (FFR≤0.8) were correctly categorised by the IVUS-based vFAI (vFAI≤0.8). CONCLUSION: The proposed approach allows the complete and comprehensive assessment of coronary stenoses providing anatomic and physiologic information, pre- and post-intervention, using only an IVUS catheter without the use of a pressure wire.

Assessment and management of coronary artery disease in kidney and pancreas transplant candidates.

: Patients with end-stage renal disease (ESRD) undergoing evaluation for kidney and/or pancreas transplantation represent a population with unique cardiovascular (CV) profiles and unique therapeutic needs. Coronary artery disease (CAD) is common in patients with ESRD, mediated by both the overrepresentation and higher prognostic value of traditional CV risk factors amongst this population, as well as altered cardiovascular responses to failing renal function, likely mediated by dysregulation of the renin-angiotensin-aldosterone system (RAAS) and abnormal calcium and phosphate metabolism. Within the ESRD population, obstructive CAD correlates highly with adverse coronary events, including during the peri-transplant period, and successful revascularization may attenuate some of that increased risk. Accordingly, peri-transplant coronary risk assessment is critical to ensuring optimal outcomes for these patients. The following provides a review of CAD in patients being evaluated for kidney and/or pancreas transplantation, as well as evidence-based recommendations for appropriate peri-transplant evaluation and management.

Prevalence, indications and management of balloon uncrossable chronic total occlusions: Insights from a contemporary multicenter US registry.

BACKGROUND: Balloon uncrossable lesions can be challenging to treat, requiring specialized techniques and equipment. METHODS: We examined the prevalence, clinical and angiographic characteristics, management and procedural outcomes of balloon uncrossable lesions in a multicenter chronic total occlusion (CTO) percutaneous coronary intervention (PCI) registry. RESULTS: Between 2012 and 2016, 718 CTO PCIs (in which the occlusion was successfully crossed with a guidewire) were performed in 701 patients at 11 US centers. Mean age was 65.6 ± 10 years and 84% of the patients were men. Balloon uncrossable lesions represented 9% of all CTOs. Balloon uncrossable CTOs had more moderate/severe calcification (82% vs. 52%, P < 0.0001), moderate/severe tortuosity (61% vs. 35% P < 0.0001) and higher J-CTO score (2.95 ± 1.32 vs. 2.43 ± 1.23, P = 0.005) as compared with the remaining lesions. Technical and procedural success was significantly lower for balloon uncrossable lesions (90.5% vs. 98.3%, P < 0.0001 and 88.9% vs. 96.6% P = 0.004), respectively, but the incidence of major adverse events was similar (1.6% vs. 2.2%, P = 0.751). Balloon uncrossable lesions required longer procedure (208 [interquartile range: 135, 258] vs. 135 [94, 194] min, P < 0.0001) and fluoroscopy (77 [52, 100] vs. 45 min [27, 75], P < 0.0001) time. Techniques used to treat balloon uncrossable lesions included balloon-assisted microdissection (23%), excimer laser atherectomy (18%), and rotational atherectomy (16%). Excimer laser atherectomy and balloon-assisted microdissection were associated with the highest technical and procedural success rates. CONCLUSIONS: Balloon uncrossable CTOs are common, are associated with high rates of technical failure, and require specialized techniques for successful treatment. © 2016 Wiley Periodicals, Inc.

Determinants and assessment of regurgitation after mitral valve repair.

OBJECTIVES: The ability to detect residual regurgitation is important in the management of patients after mitral valve repair. We performed a study of 264 patients to determine the risk factors and to compare the accuracy of clinical assessment with that of echocardiography. METHODS: Operative details and valve pathologic data were obtained from individual patient case notes. Clinical assessment consisted of history, examination, and electrocardiography. The presence of regurgitation was ranked in 7 grades, from none to severe. Transthoracic echocardiography was performed blinded to and independently of clinical assessment on the same visit and was graded similarly. Univariate analyses of demographic, etiologic, and operative variables were performed. Significant factors were entered into a multivariate logistic regression model. Sensitivities and specificities were calculated for each diagnostic modality, and the kappa statistic was used to express agreement. RESULTS: Mean (+/- SE) freedoms from regurgitation at 1 and 5 years were 91.5% +/- 1.7% and 47.5% +/- 3.2%. Factors independently associated with postoperative regurgitation were poor ventricular function (P =.04), increased age (P =.01), and chordal procedures (P =.006). When assessing the presence of regurgitation, auscultation conferred a specificity of 78%, a sensitivity of 77%, and a kappa of 0.43 relative to echocardiography. Electrocardiographic criteria for left ventricular hypertrophy were superior, with a complete specificity of 100% but a low sensitivity of 15%. Agreement within 7 grades of severity was moderate, with a weighted kappa value of 0.42. CONCLUSIONS: The hazard function for regurgitation after mitral repair increases steadily after the third year, with ventricular function, age and chordal procedures as independent risks. Clinical assessment and electrocardiography are excellent in identifying regurgitation, but their agreement is less when grading severity.