Ischemia In Coronary Patients Research Articles

Ischemia-Guided Coronary Revascularization Following Lower-Extremity Revascularization Improves 5-Year Survival of Patients With Chronic Limb-Threatening Ischemia.

To determine whether diagnosis of asymptomatic (silent) coronary ischemia using coronary computed tomography (CT)-derived fractional flow reserve (FFRCT) together with targeted coronary revascularization of ischemia-producing coronary lesions following lower-extremity revascularization can reduce adverse cardiac events and improve long-term survival of patients with chronic limb-threatening ischemia (CLTI). Prospective cohort study of CLTI patients with no cardiac history or symptoms undergoing elective lower-extremity revascularization. Patients with pre-operative coronary computed tomography angiography (CTA) and FFRCT evaluation with selective post-operative coronary revascularization (FFRCT group) were compared with patients with standard pre-operative evaluation and no post-operative coronary revascularization (control group). Lesion-specific coronary ischemia was defined as FFRCT≤0.80 distal to a coronary stenosis with FFRCT≤0.75 indicating severe ischemia. Endpoints included all-cause death, cardiac death, myocardial infarction (MI) and major adverse cardiovascular (CV) events (MACE=CV death, MI, stroke, or unplanned coronary revascularization) during 5 year follow-up. In the FFRCT group (n=111), FFRCT analysis revealed asymptomatic (silent) coronary ischemia (FFRCT≤0.80) in 69% of patients, with severe ischemia (FFRCT≤0.75) in 58%, left main ischemia in 8%, and multivessel ischemia in 40% of patients. The status of coronary ischemia in the control group (n=120) was unknown. Following lower-extremity revascularization, 42% of patients in FFRCT had elective coronary revascularization with no elective revascularization in controls. Both groups received guideline-directed medical therapy. During 5 year follow-up, compared with control, the FFRCT group had fewer all-cause deaths (24% vs 47%, hazard ratio [HR]=0.43 [95% confidence interval [CI]=0.27-0.69], p<0.001), fewer cardiac deaths (5% vs 26%, HR=0.18 [95% CI=0.07-0.45], p<0.001), fewer MIs (7% vs 28%, HR=0.21 [95% CI=0.10-0.47], p<0.001), and fewer MACE events (14% vs 39%, HR=0.28 [95% CI=0.15-0.51], p<0.001). Ischemia-guided coronary revascularization of CLTI patients with asymptomatic (silent) coronary ischemia following lower-extremity revascularization resulted in more than 2-fold reduction in all-cause death, cardiac death, MI, and MACE with improved 5 year survival compared with patients with standard cardiac evaluation and care (76% vs 53%, p<0.001). Silent coronary ischemia in patients with chronic limb-threatening ischemia (CLTI) is common even in the absence of cardiac history or symptoms. FFRCT is a convenient tool to diagnose silent coronary ischemia perioperatively. Our data suggest that post-surgery elective FFRCT-guided coronary revascularization reduces adverse cardiac events and improves long-term survival in this very-high risk patient group. Randomized study is warranted to finally test this concept.

Incremental value of a CCTA-derived AI-based ischemia algorithm over standard CCTA interpretation for coronary ischemia in patients with suspected coronary artery disease

Abstract Background Coronary computed tomography angiography (CCTA) is a widely used non-invasive test to diagnose coronary artery stenosis in patients with suspected coronary artery disease (CAD). Positive predictive value for ischemia has been suboptimal using clinical reading. A novel AI-based ischemia algorithm applying machine learning that considers an array of atherosclerotic and vascular morphology features from CCTA images has been suggested to improve the diagnostic performance for ischemia. Purpose This study aims to evaluate the incremental diagnostic performance of CCTA derived AI-based ischemia algorithm in evaluating myocardial ischemia. Methods Patients with suspected CAD referred for CCTA at Turku University Hospital from February 2007 to December 2016 were analysed. The AI-based ischemia algorithm was calculated by analysts blinded for patient characteristics and clinical outcomes using typically-acquired CCTA images. In diagnostic reading significant stenosis defined by a stenosis &amp;gt; 50% on CCTA. The reference standard was ischemia detected by stress 15O-H2O positron emission tomography (PET). Results A total of 1445 patients (mean age 63 ± 9 years, 46% male) were included in this analysis. Myocardial ischemia by PET was detected in 384 (27%) patients while the other patients had either normal PET or had non-obstructive CAD by CCTA. A positive AI-based ischemia algorithm was found in 431 (30%) patients. The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of the AI-based ischemia algorithm for the assessment of myocardial ischemia were 83%, 74%, 86%, 66%, and 90%, respectively. Compared with diagnostic reading of CCTA (area under the receiver operating characteristic curve [AUC], 0.853; 95%CI 0.832-0.874), the model including clinical reading and AI-based ischemia algorithm demonstrated superior discrimination of myocardial ischemia (AUC 0.883; 95%CI 0.863-0.904, p-value &amp;lt;0.001). (Figure) Conclusions A novel AI-based ischemia algorithm derived from CCTA improves diagnostic accuracy compared with clinical reading of CCTA in assessing myocardial ischemia by PET perfusion imaging in patients with suspected CAD.Figure

Comparing of Peak Longitudinal strain and Post Systolic Shortening in detecting ischemia at rest in stable coronary artery disease: an angiography verified study

Abstract Funding Acknowledgements Type of funding sources: None. Background Coronary artery disease is a major public health problem. Early diagnosis and treatment of coronary artery disease is crucial. There is a need for a practical, reliable and cost-effective non-invasive imaging tool. We aimed to evaluate the rest ischemia with speckle tracking echocardiography (STE) compare to the two methods in patients who were scheduled coronary angiography according to the stress tests. Methods We included fifty patients with stable angina pectoris who were scheduled for conventional coronary angiography after the stress tests in our study. Speckle tracking echocardiography was performed just before coronary angiography. The association of 2 parameters with coronary artery disease was investigated and compared. Results Among 50 patients recruited for the study, 38 of them had severe CAD (&amp;gt;50%), whereas 12 patients had non-significant CAD. Post systolic shortening (PSS) was significantly related with CAD (p&amp;lt;0.0001). The relationship of PLS with the area at risk was found to be statistically insignificant but global longitudinal strain (GLS) was significantly lower in patients with severe CAD (p = 0.011). Conclusion PSS may detect coronary ischemia in patients with stable coronary artery disease and it is more sensitive and specific in patients with stable CAD. PSS is a very useful, practical and easy applicable non invasive tool for the detection of severe coronary artery disease at rest.

КОЛИЧЕСТВЕННОЕ ОПРЕДЕЛЕНИЕ ЭНАЛАПРИЛА МАЛЕАТА В СУБСТАНЦИИ И ТАБЛЕТКАХ МЕТОДОМ ГАЛЬВАНОСТАТИЧЕСКОЙ КУЛОНОМЕТРИИ

Enalapril, belonging to the class of ACE inhibitors, is one of the leading drugs in the treatment of cardiovascular diseases and is used to treat essential hypertension of any severity, renovascular hypertension, heart failure and its prevention, as well as the prevention of coronary ischemia in patients with left ventricular dysfunction. Increasing requirements for the quality of pharmaceutical substances and pharmaceutical dosage forms create conditions for improving existing and creating new analytical developments performed using modern instrumentation. A promising method for quality control of pharmaceutical substances is the method of galvanostatic coulometry, in particular, coulometric titration with electrogenerated hydroxide ions, in which the main controlled parameters are time and current flowing through the electrochemical cell. Electrogenerated hydroxide ions are formed during the electrolysis of water. As an electron carrier, sodium sulfate, potassium sulfate, and other salts are usually used. Currently, devices are being produced that allow you to measure these parameters automatically with high accuracy. Galvanostatic coulometry is distinguished by the simplicity of the experiment, rapidity, and accuracy. Does not require expensive equipment, preliminary standardization of the titrant, the use of standard samples (except for the determination of water by the Karl Fischer method). Electrogenerated hydroxide ions interact with enalapril maleate quickly and quantitatively in a ratio of 3:1. Unified methods have been developed for the quantitative determination of enalapril maleate in the substance and tablets by coulometric titration with electrogenerated hydroxide ions. The auxiliary components of the tablet mass do not interfere with the determination of the active ingredient. The relative standard deviation does not exceed 0.6%, the relative error of the mean does not exceed 0.8%. Methods can be used in the practice of control and analytical laboratories to assess the parameter "Assay" in the substance and tablets.

Diagnosis and Treatment of Silent Coronary Ischemia May Reduce Adverse Cardiac Events and Improve Long-Term Survival of Patients Undergoing Lower-Extremity Revascularization

Background: Patients with Peripheral Artery Disease (PAD) undergoing lower-extremity revascularization are at increased risk of death and Myocardial Infarction (MI) due to co-existing Coronary Artery Disease (CAD) which is often unrecognized due to absence of chest pain symptoms. A new cardiac diagnostic test, coronary CT-derived Fractional Flow Reserve (FFRCT), can identify patients with unsuspected (silent) coronary ischemia. We sought to determine whether pre-operative diagnosis of silent coronary ischemia using FFRCT can facilitate multidisciplinary care to reduce post-operative death and MI and improve survival of PAD patients. Methods: Symptomatic PAD patients with no cardiac history or symptoms were enrolled in a prospective, open-label study of coronary CTA and FFRCT testing before lower-extremity revascularization and were compared to historic control patients with standard pre-operative cardiac evaluation and care. Lesion-specific coronary ischemia was defined as FFRCT ≤ 0.80 distal to a coronary stenosis. Endpoints included Cardiovascular (CV) death, MI and allcause death through 1 year follow up. Results: Baseline characteristics of the CTA-FFRCT (n=135) and Control (n=135) groups were similar with regard to age (66 ± 8 years), gender, co-morbidities and indication for surgery (>80% for CLTI). CTA-FFRCT evaluation revealed unsuspected (silent) coronary ischemia in 68% of patients and 40% of patients had elective post-operative coronary revascularization (PCI in 47, CABG in 7). The status of coronary ischemia was unknown in Control patients and none had elective coronary revascularization. At one year, CTA-FFRCT had fewer CV deaths (0.7% vs. 5.9%, p=0.04) and MIs (2.2% vs. 8.1%, p=0.03) and improved survival (99.3% vs. 94.1%, p=0.02) compared to Control. Conclusion: Pre-operative diagnosis of silent coronary ischemia in patients undergoing lower-extremity revascularization surgery can identify high-risk patients and facilitate multi-disciplinary patient care with selective post-operative coronary revascularization. This strategy reduced post-operative death and MI and improved one-year survival compared to standard care.

Diagnosis and management of silent coronary ischemia in patients undergoing carotid endarterectomy

BackgroundCoronary artery disease is the primary cause of death in patients with carotid artery disease and silent ischemia is a marker for adverse coronary events. A new noninvasive cardiac diagnostic test, coronary computed tomography-derived fractional flow reserve (FFRCT) can reliably identify ischemia-producing coronary stenosis in patients with coronary artery disease and help to select patients for coronary revascularization. The purpose of this study is to determine the prevalence of silent coronary ischemia in patients undergoing carotid endarterectomy (CEA) and to evaluate the usefulness of FFRCT in selecting patients for coronary revascularization to decrease cardiac events and improve survival. MethodsPatients with no cardiac history or symptoms admitted for elective CEA were enrolled in a prospective, open-label, institutional review board-approved study and underwent preoperative coronary computed tomography angiography (CTA) and FFRCT with results available to physicians for patient management. Lesion-specific coronary ischemia was defined as FFRCT of 0.80 or less distal to a focal coronary stenosis with an FFRCT of 0.75 or less, indicating severe ischemia. Primary end point was incidence of major adverse cardiovascular events (MACE; defined as cardiovascular death, myocardial infarction, or stroke) at 30 days and 1 year. ResultsCoronary CTA and FFRCT was performed in 90 CEA patients (age 67 ± 8 years; male 66%). Lesion-specific coronary ischemia was found in 51 patients (57%) with a mean FFRCT of 0.71 ± 0.14. Severe coronary ischemia was present in 39 patients (43%), 26 patients had multivessel ischemia, and 5 had left main disease. CEA was performed as scheduled in all patients with no postoperative deaths or myocardial infarctions. There were no MACE events at 30 days. After recovery from surgery, 36 patients with significant lesion-specific ischemia underwent coronary angiography with coronary revascularization (percutaneous coronary intervention or coronary artery bypass grafting) in 30 patients (33%). Survival at 1 year was 100% and freedom from MACE was 98%. ConclusionsPatients undergoing CEA have a high prevalence of unsuspected (silent) coronary ischemia, which may place them at risk for coronary events. Preoperative diagnosis of silent ischemia using CTA and FFRCT can identify high-risk patients and help to guide patient management. Selective postoperative coronary revascularization of patients with significant ischemia may decrease the risk of cardiac events and improve survival, but longer follow-up is needed and prospective, controlled trials are indicated.

Magnetocardiography for identification of coronary ischemia in patients with chest pain and normal resting 12‐lead electrocardiogram

BackgroundIdentification of coronary ischemia in patients presenting with chronic chest pain is difficult as resting ECG can be normal. Diagnosis of coronary ischemia requires evaluation during exercise or pharmacological stress. A noninvasive test to identify coronary ischemia at rest without the need for exercise is desirable. We studied the diagnostic accuracy of magnetocardiography (MCG) at rest to detect coronary ischemia in these patients.MethodsPatients with chronic chest pain and suspected coronary ischemia with a normal ECG were included. Patients underwent treadmill test (TMT) and were divided into TMT positive and TMT negative groups. MCG was recorded in a magnetically shielded room. Iso‐field contour maps generated at the T‐wave peak were compared between the groups. From the magnetic field map (MFM), the magnetic field angle at T‐wave peak was calculated and was also compared across the two groups.ResultsThere were a total of 29 patients, 12 with positive TMT and 17 with negative TMT. An abnormal magnetic field angle was more common in the TMT positive group (72% vs. 6%). Abnormal contour maps in the form of nondipole patterns or abnormal orientation were seen in 81.8% (9/11) patients in TMT positive group and 6.8% (1/17) patients in the TMT negative group (p < .001).ConclusionAbnormal magnetic field angle and abnormal magnetic field maps in MCG recorded at rest are able to identify the presence of coronary ischemia in patients with chronic chest pain and a normal resting ECG.

TCTAP A-120 Management of Silent Coronary Ischemia in Patients with Symptomatic Peripheral Vascular Disease Who Require Surgery

Complications of coronary artery disease (CAD) are the major causes of postoperative major adverse cardiac events (MACE) in patients undergoing peripheral vascular surgery (PVS). Pre-operative invasive angiography (ICA) before PVS is recommended only for patients with proven myocardial ischemia or

A PPARα Promoter Variant Impairs ERR-Dependent Transactivation and Decreases Mortality after Acute Coronary Ischemia in Patients with Diabetes

Activation of peroxisome proliferator-activated receptor alpha (PPARα) occurs in animal models of diabetes (DM) and is implicated in pathological responses to myocardial ischemia. Using bioinformatics, we identified a single nucleotide polymorphism (SNP) in the PPARα gene promoter (PPARA −54,642 G>A; rs135561) that altered the consensus sequence for a nuclear receptor binding site. Electrophoretic mobility shift assays showed that the domain bound two known PPARA transcriptional activators, estrogen-related receptor (ERR)-α and -γ and that PPARA G bound with greater affinity than PPARA A (>2-fold; P<0.05). Likewise, promoter-reporter analyses showed enhanced transcriptional activity for PPARA G vs. PPARA A for both ERR-α and -γ (3.1 vs.1.9-fold; P<0.05). Since PPARα activation impairs post-ischemic cardiac function in experimental models of DM, we tested whether decreased PPARA transcription in PPARA A carriers favorably impacted outcome after acute coronary ischemia in 705 patients hospitalized with acute coronary syndromes (ACS; 552 Caucasian, 106 African American). PPARA A allele frequencies were similar to non-diseased subjects. However, PPARA genotype correlated with 5-year mortality in diabetic (22.2% AA vs. 18.8% AG vs. 39.5% GG; P = 0.008), but not non-diabetic (P = 0.96) subjects (genotype by diabetes interaction P = 0.008). In the diabetic ACS subjects, PPARA A carriers had strikingly reduced all-cause mortality compared to PPARA G homozygotes, (unadjusted HR 0.44, 95% CI 0.26–0.75; P = 0.003; adjusted HR 0.48, 95% CI 0.27–0.83; P = 0.009). Consistent with previous descriptions of PPARα in experimental models and human disease, we describe a novel PPARA promoter SNP that decreases transcriptional activation of PPARA and protects against mortality in diabetic patients after ACS.

Exercise-induced myocardial ischemia in patients with coronary artery ectasia without obstructive coronary artery disease

Background: Aetiology, clinical significance and treatment options for coronary artery ectasia/aneurysm is not clear. Objective: We sought to determine whether exercise can induce coronary ischemia in patients with coronary artery ectasia/aneurysm without significant coronary stenosis. Methods: Coronary artery ectasia was defined as 1.5–2-fold, aneurysm as >2-fold luminal dilatation of the adjacent normal segment. The study patients could have irregularities with ectatic coronaries but they did not have stenotic lesions >50% with visual assessment of two blinded observers. Patients having coronary artery ectasia or aneurysm with prior myocardial infarction, dilated cardiomyopathy, valvular heart disease, bundle branch block, significant ST-T changes were excluded. The control group was formed from a well matched population of 32 patients with normal coronary arteries who have not performed a treadmill test before coronary angiography. The study group underwent a symptom limited treadmill test if they did not have one before coronary angiogram, all control patients underwent treadmill test. Results: Thirty-three patients with coronary artery ectasia/aneurysm (ranging from one to three vessels) but without significant stenosis were derived from 4470 cardiac catheterization procedures between January 1998 and July 2000. In the study group, 17 of the patients had positive treadmill tests with respect to five patients in the control group ( P=0.004). In subgroup analysis, diffuse ectasia/aneurysm (involving 2–3 vessels) was found to be strongly related with ischemia ( P=0.005) with respect to local disease. Conclusion: Coronary artery ectasia/aneurysm may lead to exercise induced ischemia, especially in the diffuse form.

D -Dimer is an early diagnostic marker of coronary ischemia in patients with chest pain

Background Chest pain is a frequent symptom in the emergency department and often presents a diagnostic challenge. Because coronary thrombosis is a hallmark of acute ischemic syndromes, the substrates of the coagulation and fibrinolysis cascades may be markers of coronary ischemia. The objective of this study was to determine the diagnostic value of several hemostatic markers in patients presenting to the emergency department (ED) with chest pain syndromes. Methods Two hundred fifty-seven consecutive patients with acute chest pain were studied in this prospective study conducted in an urban ED. D- Dimer levels were measured at admission to the ED in all patients. We also measured thrombin-antithrombin complexes, prothrombin fragment 1+2, activated factor VII, and fibrinogen. We used regression analysis to estimate the likelihood of myocardial infarction and the diagnostic value of D -dimer. ResultsD -Dimer and fibrinogen levels were significantly higher in patients with acute ischemic events (myocardial infarction and unstable angina) than in nonischemic patients (P <.01 and P =.02, respectively). The other hemostatic markers were not significantly elevated in patients with ischemic events. D -Dimer level >500 μg/L had an independent diagnostic value for myocardial infarction and increased the diagnostic sensitivity of the electrocardiogram and history from 73% to 92%. ConclusionD -Dimer, an expression of ongoing thrombus formation and lysis, is a marker of substantial incremental value for the early diagnosis of acute coronary syndromes presenting with chest pain. It adds independent information to the traditional assessment for myocardial infarction. D -Dimer can be incorporated into clinical decision models in the ED. (Am Heart J 2000;140:379-84.)

Effect of type A behavioral counseling on frequency of episodes of silent myocardial ischemia in coronary patients

Thirteen of 32 patients with coronary heart disease who also exhibited symptoms and signs of severe time urgency and hostility (the two overt components of type A behavior [TAB]) were found to exhibit multiple episodes of silent myocardial ischemia over a 48-hour period of Holter monitoring as indicated by electrocardiogram ST depressions. Ten of these 13 patients were given 14 months of TAB counseling in an attempt to diminish the intensity of their time urgency and hostility. The remaining three patients served as controls. After counseling, the intensity of the time urgency and hostility of the 10 counseled patients diminished 53% and 59%, respectively, as measured by the videotaped clinical examination. The time urgency and hostility of the three uncounseled control patients did not significantly change. The mean frequency of ischemic episodes in the 10 patients who received TAB counseling significantly declined from an initial 6.6 to 3.1 ischemic episodes per 24 hours. However, the mean frequency of ischemic episodes did not significantly decline in 2 of the 3 uncounseled patients. The third uncounseled patient developed a conduction defect in the 14-month interlude, making an analysis of his repeat 48-hour electrocardiogram for episodes of ST depression impossible.

Echocardiographic monitoring of mental stress test in ischemic heart disease

Mental stress testing can induce ischemia in coronary patients, but often may not induce chest pain and/or electrocardiographic changes. Therefore, we tested the utility of echocardiography to increase the sensitivity of the method. For this purpose, 56 patients undertook arithmetic mental stress tests and then were subjected to coronary angiography. During the test we evaluated left ventricular function, electrocardiography results, and emotional involvement measured by STAI (State Trait Anxiety Inventory). Echocardiography was positive in 21 patients, and electrocardiogram only in 2 patients. No patient complained of chest pain. The remaining 35 patients were negative. Comparing echo data with coronary angiography, in all the cases, sensitivity was 73.5%, specificity 93.3%. Analysis of the STAI revealed that the negative test we observed could be due to a low stressor efficacy. In conclusion, echocardiography in mental stress testing permits improved sensitivity, with loss of specificity in comparison with conventional electrocardiographic monitoring.

Greater relief of myocardial ischemia in coronary patients by aortocoronary bypass surgery compared to modern medical antianginal therapy: Documentation by exercise stress testing and myocardial oxygen needs

Greater relief of myocardial ischemia in coronary patients by aortocoronary bypass surgery compared to modern medical antianginal therapy: Documentation by exercise stress testing and myocardial oxygen needs