Modelled impact of virtual fractional flow reserve in patients undergoing coronary angiography (VIRTU-4).

BACKGROUND: The practical application of 'virtual' (computed) fractional flow reserve (vFFR) based on invasive coronary angiogram (ICA) images is unknown. The objective of this cohort study was to investigate the potential of vFFR to guide the management of unselected patients undergoing ICA. The hypothesis was that it changes management in >10% of cases. METHODS: vFFR was computed using the Sheffield VIRTUheart system, at five hospitals in the North of England, on 'all-comers' undergoing ICA for non-ST-elevation myocardial infarction acute coronary syndrome (ACS) and chronic coronary syndrome (CCS). The cardiologists' management plan (optimal medical therapy, percutaneous coronary intervention (PCI), coronary artery bypass surgery or 'more information required') and confidence level were recorded after ICA, and again after vFFR disclosure. RESULTS: 517 patients were screened; 320 were recruited: 208 with ACS and 112 with CCS. The median vFFR was 0.82 (0.70-0.91). vFFR disclosure did not change the mean number of significantly stenosed vessels per patient (1.16 (±0.96) visually and 1.18 (±0.92) with vFFR (p=0.79)). A change in intended management following vFFR disclosure occurred in 22% of all patients; in the ACS cohort, there was a 62% increase in the number planned for medical management, and in the CCS cohort, there was a 31% increase in the number planned for PCI. In all patients, vFFR disclosure increased physician confidence from 8 of 10 (7.33-9) to 9 of 10 (8-10) (p<0.001). CONCLUSION: The addition of vFFR to ICA changed intended management strategy in 22% of patients, provided a detailed and specific 'all-in-one' anatomical and physiological assessment of coronary artery disease, and was accompanied by augmentation of the operator's confidence in the treatment strategy.

The role of gender in resting full-cycle ratio (RFR) guided coronary revascularization.

BACKGROUND: Gender-based differences in clinical outcomes of patients undergoing fractional flow reserved (FFR) guided coronary revascularization is well documented. This study aimed to compare resting full-cycle ratio (RFR) values between men and women and whether this translated into difference in clinical outcomes in patients who underwent RFR-guided coronary revascularization. METHODS: This was a retrospective single-centre study of consecutive patients who underwent RFR-guided revascularization for coronary lesions with intermediate degree of stenosis. The primary endpoint was a composite of all-cause mortality, myocardial infarction (MI), unplanned revascularization, and unstable angina requiring hospital admission at one year. RESULTS: In 373 consecutive patients (510 lesions, 26% women) there was no statistically significant difference in RFR value between men and women (0.90 ± 10 versus 0.90 ± 11, P = 0.95). There was no statistically significant difference between men and women in the primary endpoint, even after adjustment to the imbalance between the two groups [3.7% vs. 3.0%; HR 1.43, 95% CI (0.46 to 4.43), P = 0.54]; or its individual components of death (1.1% vs 0.8%, P = 0.76), MI (1.9% vs 0.8%, P = 0.38) or unplanned revascularization, including unstable angina admissions (2.6% vs 2.3%, P = 0.82). The comparable clinical outcomes were consistent across all different subgroups, including clinical presentation, diabetes status, left ventricle systolic function, kidney function, and the interrogated coronary artery. CONCLUSION: Our study suggests no significant gender-based difference in the value of RFR or 1-year clinical outcomes in patients undergoing resting physiology guided coronary revascularization.

A case of bilateral horizontal gaze palsy and concurrent esotropia.

Purpose: To report a unique case of bilateral horizontal pontine gaze palsy with concurrent esotropia, surgical management, and post-operative follow-up. Observations: A 39-year-old male presented with diplopia and a history of neurocysticercosis. He was found to have bilateral horizontal gaze palsy and concurrent esotropia, R > L. Classic bimedial rectus recess-resect surgery was done to include resection of the right lateral rectus muscle. Follow-up three months post-op demonstrates markedly improved diplopia. Conclusion and importance: We present a recommended therapeutic approach for the rare case of concurrent bilateral horizontal gaze palsy and esotropia, which should be further evaluated in longitudinal studies.

Microvascular Obstruction in Acute Myocardial Infarction, a Potential Therapeutic Target.

Microvascular obstruction (MVO) is a recognised phenomenon following mechanical reperfusion in patients presenting with ST-segment elevation myocardial infarction (STEMI). Invasive and non-invasive modalities to detect and measure the extent of MVO vary in their accuracy, suggesting that this phenomenon may reflect a spectrum of pathophysiological changes at the level of coronary microcirculation. The importance of detecting MVO lies in the observation that its presence adds incremental risk to patients following STEMI treatment. This increased risk is associated with adverse cardiac remodelling seen on cardiac imaging, increased infarct size, and worse patient outcomes. This review provides an outline of the pathophysiology, clinical implications, and prognosis of MVO in STEMI. It describes historic and novel pharmacological and non-pharmacological therapies to address this phenomenon in conjunction with primary PCI.

Percutaneous Coronary Intervention and Stenting for the Treatment of Myocardial Muscle Bridges: A Consecutive Case Series.

BACKGROUND: Myocardial muscle bridging is not uncommon; it is usually asymptomatic and on occasion can be associated with angina or even acute coronary syndrome. Traditionally, percutaneous intervention is not advocated and medical management or cardiac surgery, with unroofing of the bridge, is advised if troublesome symptoms occur. OBJECTIVE: To describe the experience and outcome of percutaneous intervention and stenting of symptomatic myocardial muscle bridges. METHODS: A retrospective analysis of prospectively collected data on all patients with symptomatic muscle bridge who were treated with stent insertion after physiologic and intravascular ultrasound assessment was performed. Follow-up of all patients up to 7 years was documented and repeat angiography was performed in 4 of these patients. RESULTS: Seven patients were identified with muscle bridge who were symptomatic and were managed with maximum medical therapy but remained symptomatic. They all underwent percutaneous procedure with physiologic assessment of the muscle bridge with fractional flow reserve and with intravascular ultrasound, which was also used to optimize the stent procedure. All patients remain well and asymptomatic with follow-up from 2-7 years. Two patients had atypical symptoms and had repeat angiography at 18 and 28 months, respectively, and 2 more patients had a follow-up angiography at 32 and 34 months; all showed patent stents and no evidence of any issues. CONCLUSION: Percutaneous intervention and stent for symptomatic muscle bridges performed with physiological and intracoronary imaging assessment and guidance may be an acceptable management modality for symptomatic MB patients, resulting in a good outcome and potentially sparing patients a highly invasive cardiac surgery.

Virtual (Computed) Fractional Flow Reserve: Future Role in Acute Coronary Syndromes.

The current management of acute coronary syndromes (ACS) is with an invasive strategy to guide treatment. However, identifying the lesions which are physiologically significant can be challenging. Non-invasive imaging is generally not appropriate or timely in the acute setting, so the decision is generally based upon visual assessment of the angiogram, supplemented in a small minority by invasive pressure wire studies using fractional flow reserve (FFR) or related indices. Whilst pressure wire usage is slowly increasing, it is not feasible in many vessels, patients and situations. Limited evidence for the use of FFR in non-ST elevation (NSTE) ACS suggests a 25% change in management, compared with traditional assessment, with a shift from more to less extensive revascularisation. Virtual (computed) FFR (vFFR), which uses a 3D model of the coronary arteries constructed from the invasive angiogram, and application of the physical laws of fluid flow, has the potential to be used more widely in this situation. It is less invasive, fast and can be integrated into catheter laboratory software. For severe lesions, or mild disease, it is probably not required, but it could improve the management of moderate disease in 'real time' for patients with non-ST elevation acute coronary syndromes (NSTE-ACS), and in bystander disease in ST elevation myocardial infarction. Its practicability and impact in the acute setting need to be tested, but the underpinning science and potential benefits for rapid and streamlined decision-making are enticing.

Operator-dependent variability of angiography-derived fractional flow reserve and the implications for treatment.

AIMS: To extend the benefits of physiologically guided percutaneous coronary intervention to many more patients, angiography-derived, or 'virtual' fractional flow reserve (vFFR) has been developed, in which FFR is computed, based upon the images, instead of being measured invasively. The effect of operator experience with these methods upon vFFR accuracy remains unknown. We investigated variability in vFFR results based upon operator experience with image-based computational modelling techniques. METHODS AND RESULTS: Virtual fractional flow reserve was computed using a proprietary method (VIRTUheart) from the invasive angiograms of patients with coronary artery disease. Each case was processed by an expert (>100 vFFR cases) and a non-expert (<20 vFFR cases) operator and results were compared. The primary outcome was the variability in vFFR between experts and non-experts and the impact this had upon treatment strategy (PCI vs. conservative management). Two hundred and thirty-one vessels (199 patients) were processed. Mean non-expert and expert vFFRs were similar overall [0.76 (0.13) and 0.77 (0.16)] but there was significant variability between individual results (variability coefficient 12%, intraclass correlation coefficient 0.58), with only moderate agreement (κ = 0.46), and this led to a statistically significant change in management strategy in 27% of cases. Variability was significantly lower, and agreement higher, for expert operators; a change in their recommended management occurred in 10% of repeated expert measurements and 14% of inter-expert measurements. CONCLUSION: Virtual fractional flow reserve results are influenced by operator experience of vFFR processing. This had implications for treatment allocation. These results highlight the importance of training and quality assurance to ensure reliable, repeatable vFFR results.

The new role of diagnostic angiography in coronary physiological assessment.

The role of 'stand-alone' coronary angiography (CAG) in the management of patients with chronic coronary syndromes is the subject of debate, with arguments for its replacement with CT angiography on the one hand and its confinement to the interventional cardiac catheter laboratory on the other. Nevertheless, it remains the standard of care in most centres. Recently, computational methods have been developed in which the laws of fluid dynamics can be applied to angiographic images to yield 'virtual' (computed) measures of blood flow, such as fractional flow reserve. Together with the CAG itself, this technology can provide an 'all-in-one' anatomical and functional investigation, which is particularly useful in the case of borderline lesions. It can add to the diagnostic value of CAG by providing increased precision and reduce the need for further non-invasive and functional tests of ischaemia, at minimal cost. In this paper, we place this technology in context, with emphasis on its potential to become established in the diagnostic workup of patients with suspected coronary artery disease, particularly in the non-interventional setting. We discuss the derivation and reliability of angiographically derived fractional flow reserve (CAG-FFR) as well as its limitations and how CAG-FFR could be integrated within existing national guidance. The assessment of coronary physiology may no longer be the preserve of the interventional cardiologist.

Transcatheter aortic valve implantation facilitated by right common carotid cut-down and innominate artery angioplasty with simultaneous right coronary artery vein graft percutaneous coronary intervention in a patient with mid aortic syndrome: a case report.

BACKGROUND: Transcatheter aortic valve implantation (TAVI) is most commonly performed via the femoral approach. Small caliber ilio-femoral arteries, severe calcification and tortuosity are often prohibitive reasons for TAVI via the femoral approach. Mid-aortic syndrome is a rare condition describing congenital or acquired coarctation of the abdominal aorta. CASE SUMMARY: To the best of our knowledge, this case report describes the world's first TAVI in a patient with mid-aortic syndrome with challenging vascular access that would preclude conventional TAVI access routes. A 76-year-old woman with intermittent claudication, underwent work-up for axillo-bifemoral bypass, underwent a TAVI for incidental severe asymptomatic severe aortic stenosis via right common carotid TAVI facilitated by innominate artery angioplasty achieved vascular access for TAVI. Percutaneous coronary intervention to a right coronary artery vein graft was simultaneously performed via a left brachial artery cut down. DISCUSSION: We demonstrate that complex angioplasty to coronary artery bypass grafts and the innominate artery alongside TAVI via a variety of arterial access sites is both safe and feasible.

Right Ventricular Wall Hematoma Following Angioplasty to Right Coronary Artery Occlusion.

Right ventricle intramural hematoma is a rare complication of right coronary artery PCI. With the increased uptake and prevalence of complex chronic total occlusion interventions, unusual complications will continue to occur; sharing and raising the awareness of these complications is of paramount importance.

Force of Habit: Developing Situation Awareness in Critical Care Transport.

Situation awareness (SA) is a vital cognitive skill for high-stakes, high-hazard occupations, including military, aviation, and health care. The ability to maintain SA can deteriorate in stressful situations, exposing patients to dangerous errors. The literature regarding how to best teach SA techniques is sparse. This article explores specific techniques to promote and maintain SA in dynamic clinical environments using principles derived from cognitive psychology, neuroscience, and human behavioral and organizational research. The authors propose strategies to help individuals and teams to develop ingrained, subconscious behaviors that can help to maintain effective SA in high-stress environments. Situation awareness (SA) is critical in high-stakes circumstances, such as the resuscitation of critically ill or injured patients. Exploratory research in psychology, neuroscience, human factors engineering, and to a lesser extent health care has led to a deeper understanding of what SA is and how it can be measured. Unfortunately, little is known about how we can adapt training in order to more consistently create behaviors that heighten SA during dynamic, high-stakes clinical events. In this article, the prevailing theory of SA is reviewed, and the evidence for evaluating it in medicine is presented. In addition, the authors draw from the fields of neuroscience and cognitive psychology to suggest some strategies that can develop effective behaviors that promote SA in resuscitation.

Development and validation of a clinical risk score to predict mortality after percutaneous coronary intervention.

OBJECTIVE: To develop and validate a contemporary clinical risk score to predict mortality after percutaneous coronary intervention (PCI). METHODS: Using data collected from patients undergoing PCI at the South Yorkshire Cardiothoracic Centre, Sheffield, UK, between January 2007 and September 2013, a risk score was developed to predict mortality. Logistic regression was used to evaluate the effect of each variable upon 30-day mortality. A backwards stepwise logistic regression model was then used to build a predictive model. The results were validated both internally and externally with data from Manchester Royal Infirmary, UK. 30-Day mortality status was determined from the UK Office of National Statistics. RESULTS: The development data set comprised 6522 patients from Sheffield. Five risk factors, including cardiogenic shock, procedural urgency, history of renal disease, diabetes mellitus and age, were statistically significant to predict 30-day mortality. The risk score was validated internally on a further 3290 patients from Sheffield and externally on 3230 patients from Manchester. The discrimination of the model was high in the development (C-statistic=0.82, 95% CI 0.79 to 0.85), internal (C-statistic=0.81, 95% CI 0.76 to 0.86) and external (C statistics=0.90, 95% CI 0.87 to 0.93) cohorts. There was no significant difference between observed and predicted mortality in any group. CONCLUSION: This contemporary risk score reliably predicts 30-day mortality after PCI using a small number of clinical variables obtainable prior to the procedure, without knowledge of the coronary anatomy.

Residual SYNTAX score after PCI for triple vessel coronary artery disease: quantifying the adverse effect of incomplete revascularisation.

AIMS: There is some evidence to suggest that incompleteness of coronary artery revascularisation after PCI is associated with inferior outcomes. The SYNTAX score was developed as a tool to quantify the extent of coronary artery disease in the SYNTAX study. We aimed to use this score to quantify the completeness of revascularisation after PCI (the "residual SYNTAX score") and to determine its impact upon mortality. METHODS AND RESULTS: We studied 240 consecutive patients with native three-vessel disease who underwent PCI between 2003 and 2008. SYNTAX scores prior to, and after, PCI were calculated, the difference (ΔSYNTAX) being a measure of the relative completeness of revascularisation. Median follow-up was 2.6 (1.2-3.2) years; 21% of patients were surgical turndowns, and 38% were non-elective. A residual (rSYNTAX) score of zero (full revascularisation) was achieved in 40% and median rSYNTAX was 3.5 (0-10.9). At final follow-up reduced mortality was found in patients with rSYNTAX 0 vs. others (2.5 vs. 12%, respectively, p=0.003) and for those with rSYNTAXmedian (3 vs. 11%, p=0.003). rSYNTAX was an independent predictor of mortality in a multivariate analysis, whereas baseline SYNTAX score was not. CONCLUSIONS: The residual SYNTAX score is a useful method to quantify incomplete revascularisation in patients undergoing PCI for 3VD. Complete revascularisation (rSYNTAX=0) is achieved in only a minority and, for them, the mortality rate is low.

Impact of incomplete revascularization in patients undergoing PCI for unprotected left main stem stenosis.

INTRODUCTION: Percutaneous revascularization of patients with multivessel and left main stem (LMS) disease may be incomplete and the impact of this is not well reported and may influence outcome. In this study we assessed the role of completeness of revascularization upon outcome after PCI for unprotected left main stem (uLMS) PCI in the "real world." MATERIALS AND METHOD: Consecutive patients (n = 353) with uLMS disease were treated by PCI by a single operator with a policy of maximal feasible revascularization between 2000 and 2011. The SYNTAX score was calculated before and after PCI (residual SYNTAX score) to gauge the completeness of revascularization. The endpoints were mortality and repeat revascularization. RESULTS: Mean age was 69 ± 11 years, baseline SYNTAX score was 33.4 ± 15, 53% were nonelective, 10% were in cardiogenic shock, and 45% were not surgical candidates. LMS bifurcation was involved in 74% and 2.0 ± 0.9 other vessels were diseased. Complete revascularization was achieved in 49% and was associated with reduced mortality compared with incomplete, at 30 days [5(2.9%) v 23(13%)], 1 year [9(5%) v 34(19%)], and 3 years [14(8%) v 46(26%)]; all P < 0.0001). Median rSYNTAX score was 1(0-11), 1-year survival for the lowest, middle and highest tertiles of rSYNTAX were 1.7%, 3.1% and 7.3% (P < 0.0001), respectively. In multivariate analysis postprocedure rSYNTAX score independently predicted outcome but preprocedural SYNTAX score did not. CONCLUSIONS: For unselected patients with uLMS treated by PCI, completeness of revascularization is associated with superior survival. The rSYNTAX score, a novel index of completeness of revascularization, independently predicts survival. Baseline SYNTAX score does not.