Residual Ischemia Research Articles

Quantitative Dobutamine Stress Echocardiography Using Speckle-Tracking Analysis versus Conventional Visual Analysis for Detection of Significant Coronary Artery Disease after ST-Segment Elevation Myocardial Infarction.

Residual ischemia detection after ST-segment elevation myocardial infarction (STEMI) during dobutamine stress echocardiography (DSE) using visual analysis is challenging. The aim of the present study was to investigate the feasibility and accuracy of two-dimensional speckle-tracking strain DSE to detect significant coronary artery disease (CAD) after STEMI. First STEMI patients (n = 105; mean age, 60 ± 11 years; 86% men) treated with primary percutaneous coronary intervention undergoing full-protocol DSE at 3 months and repeat coronary angiography within 1 year were retrospectively included. Using two-dimensional speckle-tracking echocardiography, segmental and global left ventricular peak longitudinal systolic strain (PLSS) at rest and peak stress and change (Δ) in PLSS were measured. Significant CAD was defined as detection of >70% diameter stenosis at coronary angiography. In total, 1,653 (93%) and 1,645 (92%) segments were analyzable at rest and peak stress, respectively. At follow-up, 38 patients (36%) showed significant angiographic CAD. These patients demonstrated greater worsening in global PLSS from rest to peak (-16.8 ± 0.5% to -12.6 ± 0.5%) compared with patients without significant CAD (-16.6 ± 0.4% to -14.3 ± 0.3%; group-stage interaction P < .001). The optimal cutoff of ΔPLSS for the detection of significant CAD on receiver operating characteristic curve analysis was ≥1.9% (area under the curve, 0.70; sensitivity, 87%; specificity, 46%; accuracy, 60%). Using a sentinel segment approach (apex, midposterior, and midinferior for the left anterior descending, left circumflex, and right coronary artery territories, respectively), larger segmental ΔPLSS was also independently associated with significant CAD (odds ratio, 1.1; 95% CI, 1.1-1.2). Two-dimensional speckle-tracking echocardiographic strain analysis is feasible on DSE after STEMI and represents a promising new technique to detect significant angiographic CAD at follow-up.

Application of hepatic segment resection combined with rigid choledochoscope in the treatment of complex hepatolithiasis guided by three-dimensional visualization technology

To study the value of hepatic segment resection combined with rigid choledochoscope by the three-dimensional (3D) visualization technology in the diagnosis and treatment of complex hepatolithiasis. Enhance computed tomography (CT) data of 46 patients with complex hepatolithiasis who were admitted to the Zhujiang Hospital of the Southern Medical University from July 2010 to June 2014 were collected.All of the CT data were imported into the medical image three-dimensional visualization system (MI-3DVS) for 3D reconstruction and individual 3D types. The optimal scope of liver resection and the remnant liver volume were determined according to the individualized liver segments which were made via the distribution and variation of hepatic vein and portal vein, the distribution of bile duct stones and stricture of the bile duct, which provided guidance for intraoperative hepatic lobectomy and rigid choledochoscope for the remnant calculus lithotripsy. Outcomes of individual 3D types: 10 cases of type I, 11 cases of IIa, 23 cases of IIb, 2 cases of IIc, 19 cases coexisted with history of biliary surgery. The variation of hepatic artery was appeared 6 cases. The variation of portal vein was appeared 8 cases. The remaining liver volume for virtual hepatic lobectomy controlled more than 50%. Eighteen cases underwent left lateral hepatectomy, 8 cases underwent left liver resection, 8 cases underwent right posterior lobe of liver resection, 4 cases underwent the right hepatic resection, 4 cases underwent IV segment liver resection, 2 cases underwent right anterior lobe of liver resection, 2 cases underwent left lateral hepatectomy combined with right posterior lobe of liver resection, 26 cases underwent targeting treatment of rapid choledochoscope and preumatic lithotripsy. The actual surgical procedure was consistent with the preoperative surgical planning. There was no postoperative residual liver ischemia,congestion, liver failure occurred in this study. The intraoperative calculus clearance rate was 91.3% (42/46) because 4 cases of postoperatively residual calculi were not suitable for one stage management due to suppurative cholangitis but removed calculus successfully with rigid choledochoscope through T tube fistula. Hepatic segment resection combined with rigid choledochoscope under the guidance of three-dimensional visualization technology achieves accurate preoperative diagnosis and higher complete stone clearance rate of complicated hepatolithiasis.

Abstract 223: Surgical Resolution of Coronary Artery Obstruction in Incomplete Kawasaki Disease

Case Report 8 months old male, who presented with 7 days fever, hematuria, conjunctival injection and limb edema; treated as a post infectious glomerulonephritis. Twenty days later, desquamation at the tip of the fingers and in palms and soles plus thrombocytosis were found. Considering Kawasaki disease (KD), an echocardiogram was performed, finding a 5mm aneurysm in right coronary artery and 4mm ectasia in the left coronary artery. The patient was on the subacute therefore IVIG was not administered; aspirin however in antiplatelet dose range was begun. He continued on surveillance by Cardiology Department without signs of cardiac malfunction. At two years follow up a new echocardiogram was performed, showing a left coronary aneurism of 6mm and a right coronary artery of 2.0mm which was difficult to identify. Left ventricular function was preserved with an ejection fraction of 72%. Four years later, posterior myocardial necrosis, without acute ischemia on electrocardiography was found. A perfusion myocardial scan showed an uptake defect in apical region, both during stress and rest phase, suggesting an old apical infarction. Cardiac catheterization reported a tortuous right coronary artery with diffuse obstruction and left coronary artery aneurysm of 6.1mm. Due to findings above, heart transplant was considered. On a second perfusion scan a large perfusion defect on the inferior and septal wall, which improved during the rest phase was seen. The finding above correlates with inferior and septal myocardial infarction and residual ischemia. The PET-CT scan showed viable tissue in the left ventricle wall. Recently, the patient underwent revascularization surgery of right coronary artery with coronary artery bypass graft. Postsurgical echocardiogram reported a left coronary giant aneurysm of 8mm, ejection fraction of 40%, and a compromised posterior and inferior left ventricular wall function. We report the first case of surgical resolution of a coronary artery obstruction due to KD in our medical center. Because of patient’s age and coronary arteries abnormalities, a surgically intervention was the best approach in order to preserve patient’s life, cardiac function, improve the prognosis and mainly to gain time for future treatment decisions.

Usefulness of intraoperative observation using a fluorescence imaging instrument for patients with nonocclusive mesenteric ischemia.

The authors evaluated the usefulness of intraoperative photodynamic eye (PDE) observation in patients with nonocclusive mesenteric ischemia (NOMI). Between February 2012 and July 2013, 6 patients who had undergone emergency surgery for NOMI were enrolled. Intraoperative PDE observation was performed to decide the adequate length of bowel resection including all skipped dark spots, which could not be detected as ongoing mucosal ischemic changes under visible light observation. All ongoing mucosal ischemic changes were easily detected as dark spots using PDE observation in all 6 patients. The mean length of adequate ileal resection (92 ± 48 cm) was significantly longer than that of ischemic ileum (85 ± 50 cm) (mean ± SD) (P = 0.043). After resection of an adequate length of bowel, all the patients had a good course until discharge without incidents due to residual bowel ischemia, except for 1patient who died. PDE observation is useful for deciding the adequate length of bowel to resect, including ongoing mucosal ischemic changes that cannot be detected under visible light observation. In patients with NOMI, resection of an adequate length of bowel is necessary to prevent postoperative incidents due to residual bowel ischemia.

Neurological complications of vascular access.

Neurological problems are common in patients undergoing haemodialysis. Over 60% of patients will suffer from symptoms of underlying polyneuropathy due to uraemia or diabetes. Others will have subclinical disease demonstrable by nerve conduction studies. Nerve injury following haemodialysis access surgery is underreported. However, sensory nerve lesions are probably common after most vascular access procedures but are rarely debilitating. Nerve compression syndromes such as carpal tunnel and ulnar compression syndromes are common, especially in patients who have been on dialysis for some years and at least some of these are related to or exacerbated by the access. Recognition is essential as they are eminently treatable by decompression surgery. Tourniquet use appears to be safe for carpal tunnel or ulnar nerve decompression surgery. Ischaemic monomelic neuropathy (IMN) is rare but follows a period of ischaemia during or as a result of access surgery, most commonly to construct a brachial arteriovenous fistula or graft. It is characterised by intense pain, out of proportion to any ischaemia, involves all of the upper limb nerves and may progress to involve the motor nerves eventually resulting in a useless clawed hand. It requires prompt treatment of any residual ischaemia after access creation, if necessary by access ligation, as in the established syndrome, like the even rarer complication of reflex sympathetic dystrophy, it is very difficult to offer any useful treatment other than symptomatic relief and physiotherapy.

IATROGENIC AORTOCORONARY ARTERIOVENOUS FISTULA: PERCUTANEOUS MANAGEMENT OF IATROGENIC SURGICAL COMPLICATION

Iatrogenic aortocoronary arteriovenous fistula (ACAVF) resulting from placement of an arterial graft to a cardiac vein is a rare complication of CABG. Most patients present postoperatively with angina as a result of either residual ischemia due to an unbypassed artery or a coronary steal phenomenon

Fusion Image of Coronary Artery and Myocardial Perfusion Using Computed Tomography

Coronary angiography of 64-year-old man with chest pain shows the total occlusion (Fig 1, arrows) in the proximal portion of the left ascending coronary artery (LAD). Stress perfusion cardiac magnetic resonance image (MRI) depicts endocardium hypoperfusion area in the LAD territory and late gadolinium enhancement MRI showed subendocardial infarction. In this case, fusion image of coronary computed tomography (CT) and perfusion CT can present coronary lesions and following myocardial ischemia precisely. Pre-coronary artery bypass grafting (CABG) epicardial image shows the hypoperfusion area in LAD territory (Fig 2A, arrows), and subendocardial image shows the severe hypoperfusion lesion (Fig 2B, arrows). Transmural ischemic changes that were mainly seen in the anteroseptal wall were improved in the epicardium (Fig 2C) after CABG. However, subendocardial image shows residual ischemia in the subendocardium (Fig 2D, arrows), which suggests that blood flow could not be improved sufficiently with subendocardial infarction. Combined technique with perfusion CT using a 256-slice multidetector CT and a time axis interpolation technique [1Wai B. Thai W.E. Brown H. Truong Q.A. Novel phase-based noise reduction strategy for quantification of left ventricular function and mass assessment by cardiac CT: comparison with cardiac magnetic resonance.Eur J Radiol. 2013; 82: e337-e341Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar] allowed us to assess CT attenuation independent stratified myocardial ischemia.

Myocardial ischemic reduction evidenced by gated myocardial perfusion imaging after treatment results in good prognosis in patients with coronary artery disease

BackgroundThere are no nuclear cardiology reports indicating the prediction of prognosis based on ischemic reduction after revascularization in Japanese patients with coronary artery disease (CAD). We aimed to evaluate quantitatively ischemia using myocardial perfusion single photon emission computed tomography (SPECT) before and after treatment such as revascularization and to determine a relationship between the ischemic reduction and the incidence of major cardiac events (MCEs) after the treatment in patients with CAD. MethodsWe retrospectively investigated 513 patients who underwent rest 201Tl and stress 99mTc-tetrofosmin myocardial perfusion SPECT between October 2004 and March 2011 and who had a significant stenosis with 75% or greater narrowing of the coronary arterial diameter detected by coronary angiography performed after confirmation of ≥5% ischemia with SPECT. The patients underwent the treatment including revascularization and medication and thereafter were re-evaluated with SPECT during a chronic phase and followed up to confirm prognosis for ≥1 year. The follow-up period was 33.4±16.4 months. The endpoint was the incidence of the MCEs consisting of cardiac death, non-fatal myocardial infarction, and unstable angina pectoris. ResultsDuring the follow-up, 45 patients experienced MCEs comprising cardiac death (n=13), non-fatal myocardial infarction (n=3), and unstable angina pectoris (n=29). The multivariate Cox proportional hazards regression model analysis for the risk of the MCEs showed the changes in the summed difference score % (p=0.0102) and the stress left ventricular ejection fraction after the treatment (p=0.0146) as significant independent variables. The incidence of the MCEs significantly decreased in the patients with ≥5% ischemic reduction than in the patients without ≥5% ischemic reduction and in the patients without residual ischemia than in the patients with the residual ischemia. ConclusionMyocardial ischemic reduction detected by nuclear cardiology leads to a decrease in MCE rates after treatment in Japanese patients with CAD.

Abstract 153: Stress Testing Following PCI in the VA Health Care System: Insights from the VA CART Program

Background: Use of stress testing following percutaneous coronary intervention (PCI) is common in community practice with 60% of patients undergoing stress testing within 24 months of PCI. Rates of stress testing following PCI within integrated and salaried healthcare systems like the VA are unknown. Methods: Using national data from the VA Clinical Assessment Reporting and Tracking (CART) Program, we evaluated all VA patients who had PCI from October 2007-September 2011. We assessed the proportion of patients undergoing stress testing, stress test type, and timing of stress testing in the 2 years following PCI. To be consistent with prior studies, we excluded stress tests performed within 60 days of PCI as these may reflect assessment of residual ischemia in anticipation of staged procedures. Timing of follow-up stress testing was determined from 30-day incremental windows of follow-up. Results: Overall, 7,145 of 21,635 patients (33.0%) had a stress test performed within 2 years of PCI. The vast majority of stress tests following PCI were performed with nuclear imaging (80.8%). Treadmill stress ECG without imaging represented 15.2% of stress tests and stress echo 3.9%. Patients undergoing stress testing in follow-up were younger (63.4 vs 65.7 years, P&lt;.001) and less likely to have comorbid congestive heart failure (21.8% vs 25.1%, P&lt;.001) or chronic obstructive pulmonary disease (23.2% vs 25.5%, P&lt;.001). In 30-day incremental windows of follow-up, first stress tests were most commonly performed in the 60-90 days following PCI (Figure). Conclusions: About 1 in 3 patients had a stress test performed in the 2 years following PCI in the VA. This rate is nearly half that reported from prior studies of community practice. Further study is needed to understand if this represents underuse of stress testing in VA or overuse in fee-for-service care.

ST-Elevation Myocardial Infarction: Preventive Percutaneous Coronary Intervention in the Non-Culprit Vessel

Patients with ST-segment elevation myocardial infarction (STEMI) and multi-vessel disease (MVD) have poorer outcomes after primary percutaneous coronary intervention (PCI) compared to those with one-vessel coronary artery disease. Current STEMI guidelines recommend revascularization of the infarct related artery (IRA) only during primary PCI, while PCI for non-IRA lesions should be performed after objective evidence of residual ischemia. Evidence regarding the optimal management strategy for non-IRA lesions in STEMI patients with MVD has been limited and mainly based on retrospective, contradictory and probably biased data. A recently published randomized study, PRAMI, challenges the guidelines since preventive acute multi-vessel PCI for significant stenoses in non-IRAs has been associated with a reduction of major adverse cardiovascular events (MACE) compared to PCI limited to the IRA. A review of the literature and a discussion about the implications of the PRAMI study regarding the optimal revascularization strategy for STEMI with MVD are presented herein.

Registry of non-ST elevation acute coronary syndromes in a tertiary hospital (RESCATA-SEST registry)

To describe the clinical-epidemiologic profile and the process of care of the non-ST elevation acute coronary syndromes in a tertiary hospital. We analyzed the clinical information, the risk stratification and diagnostic methods, the revascularization therapy and the prescription trends at discharge, of patients with non-ST elevation acute coronary syndromes cared for in one year. Two hundred and eighty-three patients with mean age of 58 years were included (63% men). The largest number of non-ST elevation acute coronary syndromes (88.6%) was found between 50 to 59 years of age. The most common risk factor was hypertension; 82.5% of the patients had a low-intermediate TIMI score; residual ischemia was demonstrated in 37% and coronary obstructions were seen in 80 patients (70%). In 90%, a percutaneous coronary intervention was performed, mainly with drug-eluting Stents (87.5%). At discharge, even though antiplatelet agents and statins were prescribed in more than 90%, other drugs were indicated in a few more than 50% of patients. In this population, non-ST elevation acute coronary syndromes predominates in relatively young men, often with hypertension. To stratify risk, to look for residual ischemia and to revascularize with drug-eluting stents are common practices, but the evidence-based guidelines compliance is still suboptimal.

Fractional flow reserve for all coronary lesions with intermediate stenosis, a step towards optimal PCI – Single centre experience in India

BackgroundVisual assessment of intermediate coronary lesions (ICL) is fraught with errors. FFR guided PCI is often advocated but runs a potential risk of disease progression and residual ischemia. ObjectivesTo assess accuracy of visual estimation in ICL, using FFR and comparing clinical outcomes in patients with all interrogated lesions revascularized or otherwise. MethodsConsecutive patients undergoing PCI between September 2010 and 2012, who had one or more of ICL, were subjected to FFR and PCI was performed if FFR was 0.80 or less. Post-revascularization patients were divided in two groups, group I consisting of patients in whom all interrogated lesion had a significant FFR value and revascularized and group II consisting of patients with one or more non-significant lesions on FFR and left non-revascularized. The clinical end points of angina, number of anti-anginal medications prescribed and repeat revascularization were assessed at 6 months. Results74 patients had FFR done in 104 of ICL (30–80% on visual estimation) of which 37 (35.5%) lesions were considered significant (>50% diameter stenosis) by visual estimation. On confirmation with FFR visual estimation had predictive accuracy of only 57%. 87% of the patients in the group I, were free from angina, whereas 84.4% in the group II (P = 0.46) at 6 months. Also need for repeat revascularization was similar in both groups 2.5% and 2.85% respectively (P = 0.82). ConclusionVisual estimation has poor predictive accuracy in of ICL and FFR guided PCI gives good clinical outcomes, without any increase of events in interrogated but non-revascularized patients.

Les anomalies de naissance des artères coronaires à partir de l’aorte : une cause fréquente et évitable de mort subite

Anomalous aortic origin of coronary arteries is a congenital heart defect in which one coronary artery arises from the opposite sinus (the left coronary artery from the right coronary sinus, or the right coronary artery from the left sinus). The initial segment of the abnormal artery courses between the great arteries and is usually located within the aortic wall. These anomalies are far from rare, affecting 0.1% to 0.3% of the population, and carry a high risk of sudden cardiac death. It is thought that the main mechanism of cardiac death is external compression of the abnormal coronary artery between the great arteries as they expand during strenuous exercise. The risk of sudden death is particularly high in patients with an anomalous left coronary artery or associated anatomic lesions (stenotic intramural segment, slit-like deformation of the ostium), and also in young athletes. A common presentation is sudden unexplained death. The diagnosis can be made by echocardiographic examination. Silent myocardial ischemia must be sought, with stress echocardiography and stress nuclear imaging. Various surgical techniques have been described. Our own technique involves the creation of a neo-ostium in the appropriate sinus. Surgical treatment is relatively safe and provides satisfactory results, most patients having no residual myocardial ischemia under stress. Surgery is recommended for all patients with an anomalous left coronary artery, regardless of symptom status, as well as for symptomatic patients with an anomalous right coronary artery (aborted sudden death, symptoms under stress, myocardial ischemia under stress). Because of the incidence and severity of these anomalies, careful echocardiographic evaluation should be performed routinely, at least in young athletes.

STEMI patients and non-culprit lesions: what to do and when?

Patients presenting with STEMI often have multiple lesions in the non-infarct-related coronary arteries with an incidence of between 40 and 60%. The presence of severe lesions in the non-infarctrelated coronary arteries is associated with a higher chance of presenting with cardiogenic shock, electrical instability and poorer outcome after primary PCI 1 . A problem which is confronted on an almost daily basis is what to do with these unexpectedly encountered non-infarct-related lesions. It is surprising how often these patients were “asymptomatic” before presenting acutely. The current 2012 ESC guidelines for management of STEMI patients dictates that primary PCI should be limited to the culprit vessel with the exception of cardiogenic shock and persistent ischaemia after successful PCI of the culprit vessel (class 2A, level B) 2 . The 2009 ESC guidelines for PCI even state that decisions about PCI of non-culprit lesions should be taken later and only guided by objective evidence of residual ischaemia 3 . However, current evidence on the optimal management strategy for non-culprit lesions in primary PCI patients is mainly based on rather old, mainly retrospective and perhaps biased data, and adequately sized randomised data are lacking. Major limitations in the relevant literature are the retrospective analysis, the confounder of baseline differences, different clinical presentation of the patients, and operator reason to perform or defer multivessel PCI. Only a few small-sized randomised studies looking at acute or staged multivessel PCI have been published. A recent literature meta-analysis by Vlaar et al showed some interesting differences in mortality outcome between culprit-only and multivessel PCI studies

Macrophage Migration Inhibitory Factor (MIF) is associated with higher collateralization grade in patients with coronary chronic total occlusions

Purpose: Chronically total occluded coronary artery (CTO) is often associated with collateral circulation that is only partially supplying to the lack of antegrade blood flow. Therefore, variable degree of residual myocardial ischemia might still be present. The macrophage migration inhibitory factor (MIF), secreted by endothelial cells, has been showed to promote in vitro the recruitment of the endothelial progenitor cells to the ischemic tissues. It is still unknown whether MIF is involved in collateral formation of patients (pts) with CTO. We evaluated the possible correlation of MIF levels with the extent of collateral circulation in pts with CTO. Methods and results: Blood collection for MIF evaluation was performed in 32 consecutive patients (n=32) undergoing to percutaneous coronary intervention (PCI) of CTO at three different sites: a) Femoral arterial sheath (ART); 2) Tip of the guiding catheter proximal to CTO (PROX); 3) Tip of the microcatheter distal to CTO (DIST) after the occlusion was crossed, but not yet dilated. MIF was also assessed at ART and PROX level in 10 patients with normal coronary arteries, class ≤ 2 identified pts with Low Collateralization Grade (LCG; n=19), Rentrop class 3 identified pts with High Collateralization Grade (HCG; n=13). MIF was analyzed with a commercially available ELISA kit. Within CTO pts, a significant MIF increase was found across the 3 sampling sites (ART: 20.9±7.4 vs. PROX: 28.0±18.8 vs. DIST 39.4±20.6 ng/ml, p<0.01). MIF was significantly higher at DIST level in HCG as compared with LCG pts (45.2±23.9 vs. 35.5±17.6 ng/ml, p=0.05), while no difference was found at PROX (26.5±9.1 vs. 28.9±21.7 ng/ml, p=0.41) or ART level (18.7±5.2 vs. 22.3±8.4 ng/ml, p=0.42). Within CTRL pts, MIF was not significantly increased at the 2 sampling sites (ART: 18.7±7.4 vs. PROX: 15.6±5.3, p=0.10). Compared with CTRL pts, MIF was found significantly elevated in CTO pts at PROX (p=0.05), but not at ART (p<0.55) level. Conclusions: Higher MIF levels are found downstream to the arterial occlusion. This along with lower levels found proximal to the occlusion and at peripheral level suggest a loco-regional MIF production. In addition, the higher the MIF levels the higher the collateralization grade.

Residual Ischemia After Revascularization in Multivessel Coronary Artery Disease

Revascularization strategies for multivessel coronary artery disease include percutaneous coronary intervention and coronary artery bypass grafting. In this study, we compared the completeness of revascularization as assessed by coronary angiography and by quantitative serial perfusion imaging using cardiovascular magnetic resonance. Patients with multivessel coronary disease were recruited into a randomized trial of treatment with either coronary artery bypass grafting or percutaneous coronary intervention. Angiographic disease burden was determined by the Bypass Angioplasty Revascularization Investigation (BARI) myocardial jeopardy index. Cardiovascular magnetic resonance first-pass perfusion imaging was performed before and 5 to 6 months after revascularization. Using model-independent deconvolution, hyperemic myocardial blood flow was evaluated, and ischemic burden was quantified. Sixty-seven patients completed follow-up (33 coronary artery bypass grafting and 34 percutaneous coronary intervention). The myocardial jeopardy index was 80.7±15.2% at baseline and 6.9±11.3% after revascularization (P<0.0001), with revascularization deemed complete in 62.7% of patients. Relative to cardiovascular magnetic resonance, angiographic assessment overestimated disease burden at baseline (80.7±15.2% versus 49.9±29.2% [P<0.0001]), but underestimated it postprocedure (6.9±11.3% versus 28.1±33.4% [P<0.0001]). Fewer patients achieved complete revascularization based on functional criteria than on angiographic assessment (38.8% versus 62.7%; P=0.015). After revascularization, hyperemic myocardial blood flow was significantly higher in segments supplied by arterial bypass grafts than those supplied by venous grafts (2.04±0.82 mL/min per gram versus 1.89±0.81 mL/min per gram, respectively; P=0.04). Angiographic assessment may overestimate disease burden before revascularization, and underestimate residual ischemia after revascularization. Functional data demonstrate that a significant burden of ischemia remains even after angiographically defined successful revascularization.

Cardiac motion compensation and resolution modeling in simultaneous PET-MR: a cardiac lesion detection study

Cardiac motion and partial volume effects (PVE) are two of the main causes of image degradation in cardiac PET. Motion generates artifacts and blurring while PVE lead to erroneous myocardial activity measurements. Newly available simultaneous PET-MR scanners offer new possibilities in cardiac imaging as MRI can assess wall contractility while collecting PET perfusion data. In this perspective, we develop a list-mode iterative reconstruction framework incorporating both tagged-MR derived non-rigid myocardial wall motion and position dependent detector point spread function (PSF) directly into the PET system matrix. In this manner, our algorithm performs both motion ‘deblurring’ and PSF deconvolution while reconstructing images with all available PET counts. The proposed methods are evaluated in a beating non-rigid cardiac phantom whose hot myocardial compartment contains small transmural and non-transmural cold defects. In order to accelerate imaging time, we investigate collecting full and half k-space tagged MR data to obtain tagged volumes that are registered using non-rigid B-spline registration to yield wall motion information. Our experimental results show that tagged-MR based motion correction yielded an improvement in defect/myocardium contrast recovery of 34–206% as compared to motion uncorrected studies. Likewise, lesion detectability improved by respectively 115–136% and 62–235% with MR-based motion compensation as compared to gating and no motion correction and made it possible to distinguish non-transmural from transmural defects, which has clinical significance given the inherent limitations of current single modality imaging in identifying the amount of residual ischemia. The incorporation of PSF modeling within the framework of MR-based motion compensation significantly improved defect/myocardium contrast recovery (5.1–8.5%, p < 0.01) and defect detectability (39–56%, p < 0.01). No statistical difference was found in PET contrast and lesion detectability based on motion fields obtained with half and full k-space tagged data.

Reasonable Incomplete Revascularization and the Role for Adjunct Medical Therapy in Ischemic Heart Disease

The goal of complete revascularization in multivessel coronary artery disease is the elimination of all ischemia-producing lesions, either through coronary artery bypass grafting or percutaneous coronary intervention. However, a substantial proportion of patients receiving contemporary revascularization undergo incomplete revascularization, often with residual ischemia. Currently, the decision of whether to pursue a complete or a limited revascularization strategy is determined by the interventional cardiologist, often in consultation with referring physicians and taking into consideration patient preference. Although there are no guideline-specific recommendations regarding completeness of revascularization, there are passionate arguments supporting the value of complete revascularization by some and the equivalence of incomplete revascularization by others. This article focuses on the evidence that underlies the controversy regarding completeness of revascularization. When interpreting current evidence in patients with multivessel coronary artery disease, decision making regarding treatment strategy should take into account four concepts: (1) incomplete revascularization is more common in clinical practice than complete revascularization; (2) the definition of incomplete revascularization is not uniform; (3) completeness of revascularization is not always superior to incomplete revascularization; and (4) all incomplete revascularization scenarios are not equivalent. We believe that a reasonable incomplete revascularization strategy needs to include a consideration of adjunctive anti-ischemic medications (in particular effective anti-ischemic therapies such as ranolazine), and active monitoring of its effectiveness in reducing residual ischemia.

Prognostic Value of Gated SPECT after Reperfusion for Acute Myocardial Infarction

Myocardial reperfusion during the course of an acute myocardial infarction improves patients' short- and long-term prognosis; coronary blood flow is successfully re-established while preserving a large amount of at-risk muscle. Clinical evolution, however, varies. Presence of residual ischemia or viable myocardial tissue affects a patient's prognosis. Assessment by noninvasive methods allows better prognostic stratification. Cardiac-gated SPECT provides appropriate parameters to support treatment selection and monitoring of these patients. Assess the prognostic value--ability to predict occurrence of major cardiac events--of perfusion and cardiac function obtained by myocardial perfusion scintigraphy in myocardial infarction patients treated by any myocardial reperfusion method, whether pharmacological or surgical. Forty patients were included, mean age 58.8 ± 9 years, diagnosed with myocardial infarction. Participants were divided into two groups: primary percutaneous transluminal coronary angioplasty (15) or thrombolysis (25). All received myocardial perfusion scintigraphy with cardiac-gated SPECT to assess perfusion and left ventricular function, and were followed for six months with telephone interviews and review of clinical records. In the 11 patients who had major cardiac events within six months of followup, a nonsignificant increase in perfusion defect extent was seen post reperfusion. Six (54.5%) of those with major cardiac events had anterior perfusion defects. In functional parameters, a significant increase in end-diastolic and end-systolic volumes and decrease in left ventricular ejection fraction were observed post stress (p = 0.006) and at rest (p = 0.001). Post-stress end-diastolic volume of ≥70 mL had a higher prognostic value for major cardiac events [sensitivity 100%; specificity 89%, area under ROC curve 0.835 (CI 0.702-0.969), p = 0.001]. Cardiac-gated SPECT is useful to identify variables (including left ventricular systolic dysfunction and dilation of left cavities, particularly left end-systolic volume of >70 mL) predictive of major cardiac events in reperfused patients, independent of treatment modality.

Sudden Cardiac Death After Myocardial Infarction in Type 2 Diabetic Patients With No Residual Myocardial Ischemia

OBJECTIVEDiabetes mellitus (DM) is a well-established risk factor for coronary artery disease. Nonetheless, it remains unclear whether DM contributes to sudden cardiac death in patients who survive myocardial infarction (MI). The objective of this study was to compare the incidence of sudden cardiac death post-MI in diabetic and nondiabetic patients with no residual myocardial ischemia.RESEARCH DESIGN AND METHODSA total of 610 consecutive post-MI patients referred to a cardiac rehabilitation program with negative exercise stress test were studied.RESULTSOf these, 236 patients had DM at baseline. Over a mean follow-up of 5 years, 67 patients with DM (28.4%) and 76 of 374 patients without DM (20.2%) had died with a hazard ratio (HR) of 1.74 (95% CI: 1.28–2.56; P < 0.001). Patients with DM also had a higher incidence of cardiac death (1.84 [1.16–3.21]; P = 0.01), principally due to a higher incidence of sudden cardiac death (2.14 [1.22–4.23]; P < 0.001). Multiple Cox regression analysis revealed that only DM (adjusted HR: 1.9 [95% CI: 1.04–3.40]; P = 0.04), left ventricular ejection fraction (LVEF) ≤30% (3.6 [1.46–8.75]; P < 0.01), and New York Heart Association functional class >II (4.2 [1.87–9.45]; P < 0.01) were independent predictors for sudden cardiac death. Among patients with DM, the 5-year sudden cardiac death rate did not differ significantly among those with LVEF ≤30%, LVEF 31–50%, or LVEF >50% (8.8 vs. 7.8 vs. 6.8%, respectively; P = 0.83).CONCLUSIONSPost-MI patients with DM, even in the absence of residual myocardial ischemia clinically, were at higher risk of sudden cardiac death than their non-DM counterparts.