Recovery Of Regional Function Research Articles

The seismic resilience-based methodology of regional building function recovery assessment

Regional assessment of the functional recovery time of urban buildings is critical for decision-making after an earthquake, both as a key indicator of seismic disaster risk and for evaluating urban resilience. However, existing studies are insufficient for assessing the functional recovery time of buildings at the city scale. To address this issue, this study proposes a new methodology for predicting the functional recovery time of an area. This approach comprehensively considers performance-based repair objectives, various damage states, and the affected building area. It offers two improvements over traditional methods based on the assumption of unlimited restoration resources within the disaster area. First, the method establishes a standard for categorizing damaged buildings into repairable and reconstructive buildings using the building damage level parameter. The existing moderate damage states are considered rough and are further divided into three detailed damage states. The distribution functions of the three new states relative to the existing moderate damage are derived from actual earthquake cases. Second, a new parameter, the reconstruction rate, which characterizes the rate of reconstruction time per unit area of a building, is proposed. The repair time per unit area of a house in a repairable state, i.e., the repair rate, is discounted based on this new parameter using the damage state as an indicator. To illustrate the methodology in more detail, we constructed an earthquake scenario for the northeastern margin of the Tibetan Plateau and then provided a detailed assessment of the postearthquake recovery time of Zhangye under the earthquake scenario. This study aims to provide valuable insights for the government to formulate appropriate predisaster prevention policies and rational postdisaster recovery and reconstruction.

Objective perimetry identifies regional functional progression and recovery in mild Diabetic Macular Oedema.

Retinal function beyond foveal vision is not routinely examined in the clinical screening and management of diabetic retinopathy although growing evidence suggests it may precede structural changes. In this study we compare optical coherence tomography (OCT) based macular structure with function measured objectively with the ObjectiveFIELD Analyzer (OFA), and with Matrix perimetry. We did that longitudinally in Type 2 diabetes (T2D) patients with mild Diabetic Macular Oedema (DMO) with good vision and a similar number of T2D patients without DMO, to evaluate changes in retinal function more peripherally over the natural course of retinopathy. Both eyes of 16 T2D patients (65.0 ± 10.1, 10 females), 10 with baseline DMO, were followed for up longitudinally for 27 months providing 94 data sets. Vasculopathy was assessed by fundus photography. Retinopathy was graded using to Early Treatment of Diabetic Retinopathy Study (ETDRS) guidelines. Posterior-pole OCT quantified a 64-region/eye thickness grid. Retinal function was measured with 10-2 Matrix perimetry, and the FDA-cleared OFA. Two multifocal pupillographic objective perimetry (mfPOP) variants presented 44 stimuli/eye within either the central 30° or 60° of the visual field, providing sensitivities and delays for each test-region. OCT, Matrix and 30° OFA data were mapped to a common 44 region/eye grid allowing change over time to be compared at the same retinal regions. In eyes that presented with DMO at baseline, mean retinal thickness reduced from 237 ± 25 μm to 234.2 ± 26.7 μm, while the initially non-DMO eyes significantly increased their mean thickness from 250.7 ± 24.4 μm to 255.7 ± 20.6 μm (both p<0.05). Eyes that reduced in retinal thickness over time recovered to more normal OFA sensitivities and delays (all p<0.021). Matrix perimetry quantified fewer regions that changed significantly over the 27 months, mostly presenting in the central 8 degrees. Changes in retinal function measured by OFA possibly offer greater power to monitor DMO over time than Matrix perimetry data.

Assessing the impact of MR-guided focused ultrasound thalamotomy on brain activity and connectivity in patients with essential tremor.

Although magnetic resonance-guided focused ultrasound (MRgFUS) at the ventral intermediate (VIM) thalamic nucleus is a novel and effective treatment for medication-refractory essential tremor (ET), it is unclear how the ablation lesion affects functional activity. The current study sought to evaluate the functional impact of MRgFUS thalamotomy in patients with ET, as well as to investigate the relationship between neuronal activity changes and tremor control. This study included 30 patients with ET who underwent MRgFUS thalamotomy with a 6-month follow-up involving MRI and clinical tremor rating. Additional sex- and age-matched healthy people were recruited for the healthy control group. The fractional amplitude of low-frequency fluctuation (fALFF) and regional homogeneity were used to identify functional alteration regions of interest (ROIs). To investigate changes after treatment, ROI- and seed-based functional connectivity (FC) analyses were performed. Patients with ET had significantly increased fALFF in the right postcentral gyrus (PoCG; ROI 1), regional homogeneity in the left PoCG (ROI 2), and regional homogeneity in the right PoCG (ROI 3, cluster-level p value family-wise error [pFWE] < 0.05), which were recovered and normalized at 6 months after MRgFUS thalamotomy. FCs between ROI 2 and the right supramarginal gyrus, ROI 2 and the right superior parietal gyrus, and ROI 3 and the left precentral gyrus were also found to be increased after treatment (cluster-level pFWE < 0.05). Furthermore, changes in fALFF, regional homogeneity, and FC values were significantly correlated with tremor relief (p < 0.05). Preoperative FC strengths were found to be inversely related to the postoperative tremor control ratio (p < 0.05). In patients with ET, the VIM lesion of MRgFUS thalamotomy resulted in symptom-related regional functional recovery associated with sensorimotor and attention networks. Preoperative FC strengths may reflect the postoperative tremor control ratio, implying that this metric could be a useful neuroimaging biomarker for predicting symptom relief in patients with ET following thalamotomy.

Coronary wave energy to predict functional recovery in patients with ischemic left ventricular dysfunction

Abstract Background Invasive coronary angiography and non-invasive viability testing are the cornerstones of diagnosing and managing ischemic left ventricular dysfunction. At present there is no single test which serves both needs but, if developed, could revolutionise investigation of this condition. Coronary wave intensity analysis (cWIA) interrogates both contractility and microvascular physiology of the subtended myocardium [1,2] and therefore has the potential to fulfil this goal. Objectives We hypothesized that cWIA measured during coronary angiography would predict functional recovery with a similar accuracy to late gadolinium enhanced cardiac magnetic resonance imaging (LGE-CMR). Methods Patients with a left ventricular ejection fraction ≤40% and extensive coronary disease were enrolled. cWIA, fractional flow reserve and microvascular resistance were assessed with a simultaneous coronary Doppler and pressure-sensing guidewire during cardiac catheterization at rest, during hyperaemia and during low-dose dobutamine stress. Viability was assessed using LGE-CMR. Regional left ventricular function was assessed at baseline and 6-month follow up after optimization of medical therapy +/− revascularization, using transthoracic echocardiography. The primary outcome was regional functional recovery. Results Forty participants underwent baseline physiology, LGE-CMR and thirty had echocardiography at baseline and 6 months; 21/42 territories demonstrated functional recovery. Resting backward compression wave energy was significantly greater in recovering than non-recovering territories (−5240±3772 vs. −1873±1605 W m–2 s–1, p=0.099, Figure 1), and had comparable diagnostic accuracy to CMR (area under the curve 0.812 vs. 0.757, p=0.649, Figure 2); a threshold of −2500 W mm–2 s–1 had 86% sensitivity and 76% specificity at predicting recovery. Backward expansion wave energy did not predict recovery. FFR was numerically higher in recovering territories (0.81±0.17 vs. 0.71±0.16, p=0.058), whilst hyperaemic microvascular resistance did not differentiate recovering from non-recovering territories (1.97±0.73 vs. 2.29±1.00, p=0.287). The likelihood of functional recovery was similar in revascularised and non-revascularised territories (15/29 vs. 6/13 respectively, p=0.739). Low-dose dobutamine stress increased the energy of all waves, but did not improve the accuracy of cWIA in predicting recovery. In a regression model, resting backward compression wave energy and optimization of medical therapy predicted functional recovery; fractional flow reserve and hyperemic microvascular resistance did not. Conclusions Backward compression wave energy has similar accuracy to LGE-CMR in the prediction of functional recovery. cWIA has the potential to revolutionise the management of ischaemic left ventricular dysfunction, in a manner analogous to the effect of fractional flow reserve on the management of stable angina. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): The British Heart Foundation Clinical Research Training Fellowship

CLOSE-TO-EFFORTLESS BREATHING PARADIGM MAPS GLOBAL AND REGIONAL LUNG FUNCTION USING ELECTRICAL IMPEDANCE TOMOGRAPHY CROSS SECTIONALLY AND LONGITUDINALLY

CLOSE-TO-EFFORTLESS BREATHING PARADIGM MAPS GLOBAL AND REGIONAL LUNG FUNCTION USING ELECTRICAL IMPEDANCE TOMOGRAPHY CROSS SECTIONALLY AND LONGITUDINALLY

USE OF DOBUTAMINE STRESS ECHOCARDIOGRAPHY TO ASSESS MYOCARDIAL VIABILITY BEFORE PCI IN TOTAL OCCLUSION OF CORONARY ARTERY IN A TERTIARY CARE CENTRE

Dobutamine stress echocardiography has significant advantages in our country due to its wide availability, portability, low cost and safety.This study was conducted with the aim to assess myocardial viability by Dobutamine Stress Echocardiography (DSE) before PCI in total occlusion of coronary artery.This study confirms that a biphasic response to dobutamine is highly predictive of postoperative recovery of regional contractile function (100% at 6th week follow-up). This studies provide evidence that, at low doses, inotropic stimulation with P- receptor agonists will result in an increase in LV function in areas of viable myocardium but not in areas of myocardial necrosis.

Viability and functional recovery after chronic total occlusion percutaneous coronary intervention.

ObjectivesThis study evaluated myocardial viability as well as global and regional functional recovery after successful chronic coronary total occlusion (CTO) percutaneous coronary intervention (PCI) using sequential quantitative cardiac magnetic resonance (CMR) imaging.BackgroundThe patient benefits of CTO PCI are being questioned.MethodsIn a single high‐volume CTO PCI center patients were prospectively scheduled for CMR at baseline and 3 months after successful CTO PCI between 2013 and 2018. Segmental wall thickening (SWT) and percentage late gadolinium enhancement (LGE) were quantitatively measured per segment. Viability was defined as dysfunctional myocardium (<2.84 mm SWT) with no or limited scar (≤50% LGE).ResultsA total of 132 patients were included. Improvement of left ventricular ejection fraction was modest after CTO PCI (from 48.1 ± 11.8 to 49.5 ± 12.1%, p < 0.01). CTO segments with viability (N = 216, [31%]) demonstrated a significantly higher increase in SWT (0.80 ± 1.39 mm) compared to CTO segments with pre‐procedural preserved function (N = 456 [65%], 0.07 ± 1.43 mm, p < 0.01) or extensive scar (LGE >50%, N = 26 [4%], −0.08 ± 1.09 mm, p < 0.01). Patients with ≥2 CTO segments viability showed more SWT increase in the CTO territory compared to patients with 0–1 segment viability (0.49 ± 0.93 vs. 0.12 ± 0.98 mm, p = 0.03).ConclusionsDetection of dysfunctional myocardial segments without extensive scar (≤50% LGE) as a marker for viability on CMR aids in identifying patients with significant regional functional recovery after CTO PCI.

Increased oxygenation is associated with myocardial inflammation and adverse regional remodeling after acute ST-segment elevation myocardial infarction.

To explore the relationships between oxygenation signal intensity (SI) with myocardial inflammation and regional left ventricular (LV) remodeling in reperfused acute ST-segment elevation myocardial infarction (STEMI) using oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR). Thirty-three STEMI patients and 22 age- and sex-matched healthy volunteers underwent CMR. The protocol included cine function, OS imaging, precontrast T1 mapping, T2 mapping, and late gadolinium enhancement (LGE) imaging. A total of 880 LV segments were included for analysis based on the American Heart Association 16-segment model. For validation, 15 pigs (10 myocardial infarction (MI) model animals and 5 controls) received CMR and were sacrificed for immunohistochemical analysis. In the patient study, the acute oxygenation SI showed a stepwise rise among remote, salvaged, and infarcted segments compared with healthy myocardium. At convalescence, all oxygenation SI values besides those in infarcted segments with microvascular obstruction decreased to similar levels. Acute oxygenation SI was associated with early myocardial injury (T1: r = 0.38; T2: r = 0.41; all p < 0.05). Segments with higher acute oxygenation SI values exhibited thinner diastolic walls and decreased wall thickening during follow-up. Multivariable regression modeling indicated that acute oxygenation SI (β = 2.66; p < 0.05) independently predicted convalescent segment adverse remodeling (LV wall thinning). In the animal study, alterations in oxygenation SI were correlated with histological inflammatory infiltrates (r = 0.59; p < 0.001). Myocardial oxygenation by OS-CMR could be used as a quantitative imaging biomarker to assess myocardial inflammation and predict convalescent segment adverse remodeling after STEMI. • Oxygenation signal intensity (SI) may be an imaging biomarker of inflammatory infiltration that could be used to assess the response to anti-inflammatory therapies in the future. • Oxygenation SI early after myocardial infarction (MI) was associated with left ventricular segment injury at acute phase and could predict regional functional recovery and adverse remodeling late after acute MI. • Oxygenation SI demonstrated a stepwise increase among remote, salvaged, and infarcted segments. Infarcted zones with microvascular obstruction demonstrated a higher oxygenation SI than those without. However, the former showed less pronounced changes over time.

Slow but Evident Recovery from Neocortical Dysfunction and Cognitive Impairment in a Series of Chronic COVID-19 Patients.

Cognitive impairment is a frequent complaint in coronavirus disease 2019 (COVID-19) and can be related to cortical hypometabolism on 18F-FDG PET at the subacute stage. However, it is unclear if these changes are reversible. Methods: We prospectively assessed the Montreal Cognitive Assessment scores and 18F-FDG PET scans of 8 COVID-19 patients at the subacute stage (once no longer infectious) and the chronic stage (˜6 mo after symptom onset). The expression of the previously established COVID-19-related covariance pattern was analyzed at both stages to examine the time course of post-COVID-19 cognitive impairment. For further validation, we also conducted a conventional group analysis. Results: Follow-up 18F-FDG PET revealed that there was a significant reduction in the initial frontoparietal and, to a lesser extent, temporal hypometabolism and that this reduction was accompanied by a significant improvement in cognition. The expression of the previously established COVID-19-related pattern was significantly lower at follow-up and correlated inversely with Montreal Cognitive Assessment performance. However, both 18F-FDG PET and cognitive assessment suggest a residual impairment. Conclusion: Although a significant recovery of regional neuronal function and cognition can be clearly stated, residuals are still measurable in some patients 6 mo after manifestation of COVID-19. Given the current pandemic situation and tremendous uncertainty concerning the long-term effects of COVID-19, the present study provides novel insights of the highest medical and socioeconomic relevance.

Viability and functional recovery after chronic total occlusion percutaneous coronary intervention

Abstract Background Current guidelines advocate viability assessment to guide percutaneous coronary intervention (PCI) of chronic coronary total occlusions (CTO). Purpose Aim of the present study was to evaluate viability as well as global and regional functional recovery after successful CTO PCI using quantitative cardiac magnetic resonance (CMR) imaging. Methods 132 patients with sequential CMR at baseline and 3-months after successful CTO PCI were prospectively recruited between 2013 and 2018. Segmental wall thickening (SWT) and percentage late gadolinium enhancement (LGE) were quantitatively measured per segment. Viability was defined as dysfunctional myocardium (&amp;lt;2.84mm SWT) with no or limited scar (≤50% LGE). Results Significant improvements in left ventricular (LV) ejection fraction (from 48.1±11.8 to 49.5±12.1%, p&amp;lt;0.01), LV end-diastolic volume (from 99.1±31.8 to 95.7±30.2ml, p&amp;lt;0.01), and LV end-systolic volume (from 54.4±30.5 to 51.2±29.3ml, p&amp;lt;0.01) were observed after CTO PCI. CTO segments with viability (N=216, (31%)) demonstrated a significantly higher increase in SWT (0.80±1.39mm) compared to CTO segments with pre-procedural preserved function (N=456 (65%), 0.07±1.43mm, p&amp;lt;0.01) or extensive scar (LGE &amp;gt;50%, N=26 (4%), −0.08±1.09mm, p&amp;lt;0.01). Improvement in SWT was comparable between segments with viability if further stratified to 0, &amp;gt;0–25, and &amp;gt;25–50% hyperenhancement (p=0.94). Patients with ≥2 CTO segments viability showed more SWT increase in the CTO territory compared to patients with 0–1 segment viability (0.49±0.93 vs. 0.12±0.98mm, p=0.03). Conclusions Improvements in LV function and volumes were significant but modest following CTO PCI. Detection of dysfunctional myocardial segments without extensive scar (≤50% LGE) as a marker for viability may aid in identifying subjects with significant regional functional recovery after CTO PCI. Funding Acknowledgement Type of funding source: None

Every minute counts: in-hospital changes of left ventricular regional and global function in patients with ST-segment elevation myocardial infarction.

The aim of our study was to assess the effects of an early percutaneous coronary intervention on changes of in-hospital left ventricular ejection fraction (LVEF) and wall motion score index (WMSI) in patients with ST-segment elevation myocardial infarction. The study population consisted of 324 consecutive patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention, divided into two groups, according to the first medical contact (FMC)-to-reperfusion time, respectively, 90 min or less (n = 173) and more than 90 min (n = 151). Moreover, we performed a sub-analysis in the group of patients who showed at discharge an improvement in the LVEF of at least 10%. In both groups at baseline, patients suffered from a moderately reduced LVEF (40.88 ± 8.38% in ≤90 min group vs. 40.70 ± 8.98% in >90 min group; P = 0.858). A WMSI of more than 1 was recorded uniformly: 1.71 ± 0.37 in patients with FMC-to-reperfusion 90 min or less and 1.72 ± 0.38 in patients more than 90 min (P = 0.810). At the time of discharge, a significant improvement in LVEF (43.82 ± 8.38%, P = 0.001) and WMSI (1.60 ± 0.41, P = 0.009) exclusively emerged in the 90 min or less group. Furthermore, we identified 105 patients who experienced an improvement in the LVEF of at least 10% compared with baseline values. In these patients FMC-to-reperfusion and total ischemic time resulted as significantly shorter, when compared with patients with LVEF improvement of less than 10%. Our study confirms and reinforces the concept that reducing the duration of the time between FMC and reperfusion, as well as the total ischemic time influences a positive recovery of left ventricular global and regional function during in-hospital stay.

1036 Prognostic role of left ventricle longitudinal strain for the prediction of survival after surgical ventricular repair

Abstract Background Surgical ventricular repair (SVR) in patients with ischemic cardiomyopathy is aimed to reshape left ventricle (LV) and reduce its volume in order to improve prognosis and quality of life. There are controversies regarding benefit of SVR, especially in patients with severely enlarged LV. Purpose Our purpose was to investigate prognostic value of LV longitudinal strain for survival and for the improvement of LV function after SVR in patients with anteroapical LV aneurysm. Methods 218 pts (2005-2018, mean age 63.6 ± 11.2y, 73.9% males) with anteroapical LV aneurysm due to myocardial infarction underwent SVR combined with coronary bypass grafting (77.5%), mitral valve repair (18.3%) and LV thrombectomy (22.0%). Preoperative strain analysis was done retrospectively for 146 patients. Prognostic value of strain was tested in pts according to the LV end systolic volume index (LVESVI) with the cut-off value of 60ml/m². In 17 pts 1-year follow-up with strain quantification was done. Results During a median follow-up of 3.9 years (IQR: 1.0-6.8 years) there were 68 deaths and 1 patient was lost to follow-up. 30-days survival rate was 93.5% (95%CI: 90.3; 96.9%), 5 year survival – 72.5% (95%CI: 66.0-79.6%). Pts who died were significantly older, with higher proportion of diabetes (DM), peripheral artery disease, renal failure (RF) and atrial fibrillation (AF). Baseline ejection fraction (EF) and global longitudinal strain (GLS) did not differ significantly. Whereas basal longitudinal strain (BLS) was higher (more negative) in pts who survived (-11.4 ± 3% vs. -10.1 ± 4%, p = 0.027). Risk stratification by tertiles revealed that BLS was a significant predictor of survival. The risk of dying was 3 times higher for pts in the lowest tertile compared to those in the highest tertile (HR: 2.94, 95%CI:1.37-6.25, p = 0.013). When adjusted to age, AF, DM, RF, and previous heart surgery, BLS was an independent predictor of death (HR = 1.14, 95%CI:1.03;1.26, p = 0.032). At 1-year follow-up (12.7 ± 5.1 months) there was significant decrease of LV end-diastolic and end-systolic volume indices, from 102.8 ± 24.1 ml/m² to 77.9 ± 24 ml/m² (p &amp;lt; 0.001) and from 67 ± 23.2 ml/m² to 44.3 ± 7.6 ml/m² (p &amp;lt; 0.001), correspondingly, and increase of EF from 36.3 ± 9.4% to 44.4 ± 7.6% (p = 0.001). The mean systolic GLS improved from -6.6 ± 2.6% to -8.7 ± 3.2%, p = 0.008. Among 81 segments with baseline hypokinesia, 44 segments (54.3%) recovered their contractility, 36 segments (44.4%) remained hypokinetic and 1 segment deteriorated to akinesia. Mean systolic strain of segments which showed recovery was -6.6 ± 4.0% compared to -3.8 ± 4.5% with no improvement (p = 0.005). Cut-off value of systolic strain for prediction of recovery was -5.4 % (AUC = 0.69, p = 0.004; PPV = 0.73, NPV = 0.61). Conclusion Our study demonstrates that BLS is an independent predictor of survival after SVR in patients with LV anteroapical aneurysm. Furthermore, higher systolic strain predicts recovery of LV regional function at 1-year after SVR.

Ischemic postconditioning improves longitudinal contractile function of the reperfused myocardium in patients with anterior wall acute myocardial infarction

To investigate whether ischemic postconditioning (IPTC) can promote the recovery of left ventricular impaired regional or global longitudinal systolic function. Methods: The trial was divided into a percutaneous coronary intervention (PCI) group, an PCI+IPTC group and a control group. Thirty-two patients with anterior acute anterior wall ST-segment elevation myocardial infarction (STEMI) underwent the first emergency PCI in the PCI group, 28 patients with anterior acute STEMI underwent the combination of PCI and IPTC in the PCI+IPTC group, while 30 patients underwent coronary angiography in the control group. Two-dimensional dynamic echocardiography was collected before operation, 0.5 h, 1 day, 3 days, 1 week, 1 month and 6 months after operation, respectively. The longitudinal strain parameters at different time points were analyzed and compared in the 3 groups. Results: The regional longitudinal strain of infracted segments in the PCI+IPTC group after the operation within 1 week was higher than that in the PCI group (P<0.05). The left ventricular global longitudinal strain in the PCI+IPTC group seemed to be higher than that in PCI group after the operation within 1 week, but there was not statistically difference (P>0.05). There was no significant difference in the long-term regional and global longitudinal strains of left ventricle between the PCI+IPTC group and the PCI group (both P>0.05). Conclusion: The IPTC can improve the short-term longitudinal systolic function of the reperfused myocardium in patients with acute anterior wall STEMI after PCI.

Recovery of regional systolic and diastolic myocardial function after acute myocardial infarction evaluated by two-dimensional speckle tracking echocardiography.

The assessment of temporal changes in systolic and diastolic regional left ventricle function by two-dimensional speckle tracking echocardiography (STE) after successful reperfusion therapy of acute myocardial infarction (AMI). A total of 97 consecutive patients admitted with AMI and treated with successful percutaneous coronary intervention were included in this study. On days 1, 2, 3, 7, 30 and 180 following admission patients underwent transthoracic echocardiography with subsequent measurement of systolic longitudinal strain (SLS), systolic longitudinal strain rate (SRS) and early diastolic longitudinal strain rate (SRe) in left ventricular segments by speckle tracking technique. The largest increase in regional SLS and SRS was observed between day 1 and 2. On days 3, 7, 30 and 180 further improvement was noticeable, but the changes were less significant. The highest prognostic value among STE parameters for predicting systolic function recovery after 6-month-long follow-up was achieved by measuring SLS on day 3 (area under the curve=0·878). The most of regional systolic function recovery occurs within the first 2days. The recovery of regional diastolic function takes longer - the most significant part of improvement occurs within the first 7days. STE parameters have prognostic value for predicting the improvement of systolic function after 180days.

Improved recovery of regional left ventricular function after PCI of chronic total occlusion in STEMI patients: a cardiovascular magnetic resonance study of the randomized controlled EXPLORE trial

BackgroundThe Evaluating Xience and left ventricular function in PCI on occlusiOns afteR STEMI (EXPLORE) trial did not show a significant benefit of percutaneous coronary intervention (PCI) of the concurrent chronic total occlusion (CTO) in ST-segment elevation myocardial infarction (STEMI) patients on global left ventricular (LV) systolic function. However a possible treatment effect will be most pronounced in the CTO territory. Therefore, we aimed to study the effect of CTO PCI compared to no-CTO PCI on the recovery of regional LV function, particularly in the CTO territory.MethodsUsing cardiovascular magnetic resonance (CMR) we studied 180 of the 302 EXPLORE patients with serial CMR (baseline and 4 months follow-up). Segmental wall thickening (SWT) was quantified on cine images by an independent core laboratory. Dysfunctional segments were defined as SWT < 45%. Dysfunctional segments were further analyzed by viability (transmural extent of infarction (TEI) ≤50%.). All outcomes were stratified for randomization treatment.ResultsIn the dysfunctional segments in the CTO territory recovery of SWT was better after CTO PCI compared to no-CTO PCI (ΔSWT 17 ± 27% vs 11 ± 23%, p = 0.03). This recovery was most pronounced in the dysfunctional but viable segments(TEI < 50%) (ΔSWT 17 ± 27% vs 11 ± 22%, p = 0.02). Furthermore in the CTO territory, recovery of SWT was significantly better in the dysfunctional segments in patients with Rentrop grade 2–3 collaterals compared to grade 0–1 collaterals to the CTO (16 ± 26% versus 11 ± 24%, p = 0.04).ConclusionCTO PCI compared with no-CTO PCI is associated with a greater recovery of regional systolic function in the CTO territory, especially in the dysfunctional but viable segments. Further research is needed to evaluate the use of CMR in selecting post-STEMI patients for CTO PCI and the effect of regional LV function recovery on clinical outcome.Trial registrationTrialregister.nl NTR1108, Date registered NTR: 30-okt-2007.

TCT-150 Recovery of regional myocardial function after CTO PCI compared to no CTO PCI in STEMI patients with a concurrent CTO

TCT-150 Recovery of regional myocardial function after CTO PCI compared to no CTO PCI in STEMI patients with a concurrent CTO

Myocardial Extracellular Volume Estimation by CMR Predicts Functional Recovery Following Acute MI

ObjectivesIn the setting of reperfused acute myocardial infarction (AMI), the authors sought to compare prediction of contractile recovery by infarct extracellular volume (ECV), as measured by T1-mapping cardiac magnetic resonance (CMR), with late gadolinium enhancement (LGE) transmural extent. BackgroundThe transmural extent of myocardial infarction as assessed by LGE CMR is a strong predictor of functional recovery, but accuracy of the technique may be reduced in AMI. ECV mapping by CMR can provide a continuous measure associated with the severity of tissue damage within infarcted myocardium. MethodsThirty-nine patients underwent acute (day 2) and convalescent (3 months) CMR scans following AMI. Cine imaging, tissue tagging, T2-weighted imaging, modified Look-Locker inversion T1 mapping natively and 15 min post–gadolinium-contrast administration, and LGE imaging were performed. The ability of acute infarct ECV and acute transmural extent of LGE to predict convalescent wall motion, ejection fraction (EF), and strain were compared per-segment and per-patient. ResultsPer-segment, acute ECV and LGE transmural extent were associated with convalescent wall motion score (p < 0.01; p < 0.01, respectively). ECV had higher accuracy than LGE extent to predict improved wall motion (area under receiver-operating characteristics curve 0.77 vs. 0.66; p = 0.02). Infarct ECV ≤0.5 had sensitivity 81% and specificity 65% for prediction of improvement in segmental function; LGE transmural extent ≤0.5 had sensitivity 61% and specificity 71%. Per-patient, ECV and LGE correlated with convalescent wall motion score (r = 0.45; p < 0.01; r = 0.41; p = 0.02, respectively) and convalescent EF (p < 0.01; p = 0.04). ECV and LGE extent were not significantly correlated (r = 0.34; p = 0.07). In multivariable linear regression analysis, acute infarct ECV was independently associated with convalescent infarct strain and EF (p = 0.03; p = 0.04), whereas LGE was not (p = 0.29; p = 0.24). ConclusionsAcute infarct ECV in reperfused AMI can complement LGE assessment as an additional predictor of regional and global LV functional recovery that is independent of transmural extent of infarction.

Epicardial infarct repair with bioinductive extracellular matrix promotes vasculogenesis and myocardial recovery

Infarcted myocardium can remodel after successful reperfusion, resulting in left ventricular dilation and heart failure. Epicardial infarct repair (EIR) using a bioinductive extracellular matrix (ECM) biomaterial is a novel surgical approach to promote endogenous myocardial repair and functional recovery after myocardial infarction. Using a pre-clinical porcine model of coronary ischemia-reperfusion, we assessed the effects of EIR on regional functional recovery, safety, and possible mechanisms of benefit. An ECM biomaterial (CorMatrix ECM) was applied to the epicardium after 75 minutes of coronary ischemia in a porcine model. Following ischemia-reperfusion injury, animals were randomly assigned in 2:1 fashion to EIR (n = 8) or sham treatment (n = 4). Serial cardiac magnetic resonance imaging was performed on normal (n = 4) and study animals at baseline (1 week) and 6 weeks after treatment. Myocardial function and tissue characteristics were assessed. Functional myocardial recovery was significantly increased by EIR compared with sham treatment (change in regional myocardial contraction at 6 weeks, 28.6 ± 14.0% vs 4.2 ± 13.5% wall thickening, p < 0.05). Animals receiving EIR had reduced adhesions compared with animals receiving sham treatment (1.44 ± 0.51 vs 3.08 ± 0.89, p < 0.05). Myocardial fibrosis was not increased, and EIR did not cause myocardial constriction, as left ventricular compliance by passive pressure distention at matched volumes was similar between groups (13.9 ± 4.0 mm Hg in EIR group vs 16.0 ± 5.2 mm Hg in sham group, p = 0.61). Animals receiving EIR showed evidence of vasculogenesis in the region of functional recovery. In addition to the beneficial effects of successful reperfusion, EIR using a bioinductive ECM enhances myocardial repair and functional recovery. Clinical translation of EIR early after myocardial infarction as an adjunct to surgical revascularization may be warranted in the future.

Abstract 9825: Cardiac Strain in a Swine Model of Regional Hibernating Myocardium: Effects of Bypass Surgery on Contractile Reserve

Background: Clinical studies have suggested that functional recovery of hibernating myocardium may be delayed following coronary artery bypass graft (CABG) surgery. We have shown in a swine model of hibernating myocardium, that recovery of regional function and oxygen consumption during an infusion of high dose catecholamine is sub-maximal at 4-weeks following CABG. Using the same swine model of hibernating hearts along with MRI estimates of circumferential strain (ECC), we tested whether contractile reserve within hibernating myocardial regions during a low dose infusion of dobutamine improves post-CABG. Methods. Ten pigs underwent thoracotomy with placement of a constrictor around the LAD artery. At 12 weeks, MRI imaging was performed prior to CABG and repeated 4-weeks following off-pump revascularization with a left internal mammary artery graft to the LAD artery. MRI studies were performed at baseline and during an infusion of low dose dobutamine (5 μg/kg/min). Results: MRI studies prior to CABG showed that circumferential strain in the Hibernating (LAD) Region was lower than the Remote Region at rest (-14.5±0.7 versus -15.1±0.7 respectively; P&lt;0.05) and did not improve during dobutamine (-14.7±0.8 versus -16.7±0.8 respectively; P&lt;0.05). Following CABG, strain measurements in the hibernating LAD region remained lower than remote regions at rest, but improved during the same dose of dobutamine (Figure). Summary: Baseline function in hibernating myocardium does not fully recover at 4 weeks post-CABG but contractile reserve during an infusion of low dose dobutamine does improve compared with estimates of strain obtained prior to surgery. Future studies should address the time course of recovery of regional function post-CABG and test whether additional interventions might facilitate earlier recovery of contractile reserve.

Abstract 10277: Effect of CoQ10 on Contractile Reserve of Hibernating Swine Myocardium Following Bypass Surgery

Background: We have previously shown that the recovery of regional function and maximal oxygen consumption in a pig model of hibernating myocardium is incomplete at 4 weeks following bypass surgery (CABG). Because clinical studies suggest a beneficial effect of chronic administration of Coenzyme Q10 (CoQ10) in ischemic heart disease, we tested the benefit of this supplement on contractile reserve, using MRI. Methods: Twelve pigs underwent placement of a constrictor around the LAD artery and had reduced function by MRI at 12 weeks. They then underwent off-pump byass using a left internal mammary artery graft and were allowed to recover. Pigs were given daily dietary supplements of either CoQ10 (10 mg/kg/day) or placebo and restudied with MRI at 4 weeks post-CABG. Images were acquired prior to and following CABG with a 3.0-T scanner (Achieva, Philips Medical Systems, Andover MA, USA), with a 4-element phased array coil on the chest and EKG gating. Regional circumferential strain (EC) measures were determined at baseline and at the time of the final study post-CABG, during an infusion of low dose dobutamine. Immediately post-stress, blood samples were obtained for analysis of troponins. Results: One animal did not survive and comparisons are made between the Placebo (N=6) and CoQ10 (N=5) groups. At 12 weeks following instrumentation and just prior to CABG, strain in the LAD region of all animals was lower than the remote regions at rest (-14.27±0.65 versus -15.13±0.69 P&lt;0.05). At 4 weeks post-CABG, baseline strain in placebo and CoQ10 groups was -12.4±1.2 and -13.7±0.8 respectively (NS). In addition to no differences in basal function, there were no intergroup differences in either contractile reserve in the LAD region, as measured by circumferential strain, or cardiac troponin levels post-stress (Figure). In summary, in this model of chronic myocardial ischemia, daily supplementation with CoQ10 did not improve basal function or contractile reserve at 4 weeks following CABG.