Effect of bivalirudin on myocardial microcirculation and adverse events after interventional therapy in older patients with acute coronary syndrome

BACKGROUND Bivalirudin,a direct thrombin inhibitor,is used in anticoagulation therapies as a substitute for heparin,especially during cardiovascular procedures such as percutaneous coronary intervention.AIM To explore the effect of bivalirudin on myocardial microcirculation following an intervention and its influence on adverse cardiac events in elderly patients with acute coronary syndrome(ACS).METHODS In total,165 patients diagnosed with acute myocardial at our hospital between June 2020 and June 2022 were enrolled in this study.From June 2020 to June 2022,elderly patients with ACS with complete data were selected and treated with interventional therapy.The study cohort was randomly divided into a study group(n=80,administered bivalirudin)and a control group(n=85,administered unfractionated heparin).Over a 6-mo follow-up period,differences in emergency processing times,including coronary intervention,cardiac function indicators,occurrence of cardiovascular events,and recurrence rates,were analyzed.RESULTS Significant differences were observed between the study cohorts,with the observation group showing shorter emergency process times across all stages:Emergency classification;diagnostic testing;implementation of coronary intervention;and conclusion of emergency treatment(P<0.05).Furthermore,the left ventricular ejection fraction in the observation group was significantly higher(P<0.05),and the creatine kinase-MB and New York Heart Association scores were CONCLUSION In elderly patients receiving interventional therapy for ACS,bivalirudin administration led to increased activated clotting time achievement rates,enhanced myocardial reperfusion,and reduced incidence of bleeding complications and adverse cardiac events.

Myocardial perfusion echocardiography and coronary microvascular dysfunction

Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation,but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography(MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction,respectively,and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall,MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice,but the approval of regulatory authorities is lacking.

Assessment of Myocardial Perfusion and Systolic Function in Patients with Coronary Artery Disease after Coronary Artery Bypass Surgery by Myocardial Contrast Echocardiography and Two-dimensional Strain Echocardiography

The clinically applied value of myocardial perfusion and systolic function in patients with coronary artery disease after coronary artery bypass surgery using real-time myocardial contrast echocardiography （RT-MCE） combined with two-dimensional strain echocardiography was assessed. Twenty patients underwent intravenous RT-MCE by intravenous injections of SonoVue before and after coronary artery bypass surgery. Two-dimensional images were recorded from the left ventricular four-chamber view, two-chamber view and the apical view before, and two weeks and three months after coronary artery bypass surgery, and the peak systolic longitudinal strain was measured. The results showed that myocardial perfusion was significantly increased after coronary artery bypass surgery in about 71.6% segments. In the group that myocardial perfusion was improved, the peak systolic longitu- dinal strain three months after bypass surgery was significantly higher than that before operation [（-15.78±5.91）% vs （-10.45±8.31）%, P〈0.05]. However, the parameters did not change in the group without myocardial perfusion improvement [（-10.33±6.53）% vs （-9.41±6.09）%, P〉0.05]. It was concluded that whether or not the improvement of myocardial perfusion can mirror the recovery trend of regional systolic function, two-dimensional strain echocardiography can observe dynamic change of regional systolic function. The combination of myocardial perfusion with two-dimensional strain echocardiography can more accurately assess the curative effectiveness of coronary artery bypass surgery.

Effect of puerarin on myocardial perfusion and ventricular wall motion in patients with acute coronary syndrome

Objective To investigate the effects of puerarin (Pur) on myocardial perfusion and ventricular wall motion in patients with acute coronary syndrome (ACS).Methods Thirty-seven patients with ACS were randomly divided into two groups:conventional treatment group (n= 17,11 males,range of age:32-80 years,average age:60.9±4.9 years) and Pur treatment group (n=20,12 males,range of age:40-76 years,average age:62.7±3.5 years).Patients in the conventional treatment group received standard treatment according to the current guidelines,while patients in the Pur treatment group received intravenous administration of Pur (500 mg/day) for 10 days plus conventional treatment.Real-time myocardial contrast echocardiography (RT-MCE) was performed to evaluate the change in myocardial perfusion index (MPI) and ventricular wall motion index (VWMI) at admission and 10 days after treatment.Results At 10 days after treatment,MPI was significantly higher (P【0.01) and VWMI significantly lower (P【0.01) in the Pur group comparing with those in the conventional group.Conclusions Puerarin might improve myocardial microcirculation perfusion and ventricular wall motion in patients with ACS.

Revascularization and outcomes in Veterans with moderate to severe ischemia on myocardial perfusion imaging

Background： The prevalence of ischemia on nuclear myocardial perfusion imaging （MPI） has been decreasing. Recent research has questioned the benefit of invasive revascularization for patients with moderate to severe ischemia. We hypothesized that patients with moderate to severe ischemia could routinely undergo successful revascularization. Methods： We analyzed data from 544 patients who underwent an MPI at a single academic Veterans Affairs Medical Center. Patients with moderate to severe ischemia, defined as a summed difference score （SDS） 8 or greater, were compared to the rest of the cohort. Results： Of the total cohort （n=544）, 39 patients had MPI studies with resultant moderate to severe ischemia. Patients with ischemia were more likely to develop coronary artery disease （74.4% versus 38.8%, P〈0.0001） and have successful revascularization （38.5% versus 4.0%, P〈0.0001） during the following year. Revascularization was attempted in 31 patients with moderate to severe ischemia, though only 15（47%） of these attempts were successful, Ischemia was predictive of myocardial infarction （5.1% versus 0.8%, P=0.01） within I year. Conclusion： Moderate to severe ischemia is an uncommon finding in a contemporary nuclear laboratory. Among patients with ischemia, revascularization is typically attempted but is frequently unsuccessful. Trial registration： This trial does not appear on a registry as it is neither randomized nor prospective.

QUANTITATIVE ASSESSMENT OF MYOCARDIAL PERFUSION DEFECTS WITH REAL-TIME THREE-DIMENSIONAL MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY

Objective To evaluate the feasibility and accuracy of measurement of myocardial perfusion defects with intravenous contrast-enhanced real-time three-dimensional echocardiography (CE-RT3DE). Methods RT3DE was performed in 21 open-chest mongrel dogs undergoing acute ligation of the left anterior descending artery (LAD, n=14) or distal branch of the left circumflex artery (LCX, n=7). A perfluorocarbon microbubble contrast agent was injected intravenously to assess the resulting myocardial perfusion defects with Philips Sonos-7500 ultrasound system. Evans blue dye was injected into the occluded coronary artery for subsequent anatomic identification of underperfused myocardium. In vitro anatomic measurement of myocardial mass after removal of the animal’s heart was regarded as the control. Blinded off-line calculation of left ventricular mass and perfusion defect mass from RT3DE images were performed using an interactive aided-manual tracing technique.Results Total left ventricular (LV) myocardial mass ranged from 38.9 to 78.5 (mean±SD: 60.0±10.1) g. The mass of perfusion defect ranged from 0 to 21.4 (mean±SD: 12.0±5.0) g or 0 to 27% of total LV mass (mean±SD: 19%±6%). The RT3DE estimation of total LV mass (mean±SD: 59.8±9.9 g) strongly correlated with the anatomic measurement (r=0.98; y=2.01+0.96x). The CE-RT3DE calculation of the mass of underperfused myocardium (mean±SD: 12.3±5.3 g) also strongly correlated with the anatomic measurement (r=0.96; y=-0.10+1.04x) and when expressed as percentage of total LV mass (r=0.95; y=-0.20+1.04x). Conclusions RT3DE with myocardial contrast opacification could accurately estimate underperfused myocardial mass in dogs of acute coronary occlusion and would play an important role in quantitative assessment of myocardial perfusion defects in patients with coronary artery disease.

Diagnosing CAD: additional markers from myocardial perfusion SPECT

Over the past decades, stress/rest myocardial perfusion SPECT （MPS） has been utilized as a standard modality for the diagnosis, risk stratification and prognostic assessment of coronary artery disease （CAD）. In addition to the perfusion information, MPS can also provide functional information of the left ventricle, including volume, ejec- tion fraction, wall motion and dyssynchrony. This article introduces the incremental value of these non-perfusion parameters as markers and prognosticators of CAD.

Contrast Limited Adaptive Histogram Equalization for Qualitative Enhancement of Myocardial Perfusion Images

This paper establishes an efficient color space for the contrast enhancement of myocardial perfusion images. The effects of histogram equalization and contrast limited adaptive histogram equalization are investigated and the one which gives good enhancement results is extended to the suitable color space. The color space which gives better results is chosen experimentally. Uniqueness of this work is that contrast limited adaptive histogram equalization technique is applied to the chrominance channels of the cardiac nuclear image, leaving the luminance channel unaffected which results in an enhanced image output in color space.

Accuracy of left ventricular function from electrocardiographygated myocardial perfusion SPECT by MyoMetrix in Chinese

This work was to determine threshold values for accurate measurements of left ventricular end-diastolic volume(EDV),end-systolic volume(ESV),and ejection fraction(EF) from electrocardiography-gated myocardial perfusion imaging(MPI) in Chinese,and these data were compared with those of echocardiography.A total of 110 patients with definite or suspected coronary artery disease were referred for both gated MPI and echocardiography within 1 week.The EDV,ESV,and EF automatically measured by MyoMetrix and echocardiography were analyzed using Bland-Altman plot correlation and paired t test.The results showed that these parameters quantified by MyoMetrix software were correlated,moderately to highly,with those on echocardiography(ρ,r ≥0.75,P<0.01).However,the EF was not significantly correlated,with post-exercise MPI ESV of <15 mL or resting MPI ESV of <20 mL.At or above this ESV value,EF was underestimated by MyoMetrix(t≥ 4.60,P<0.01).In a word,a small ESV was underestimated by MyoMetrix,which could lead to EF overestimation.On the contrary,a normal or large ESV was overestimated by MyoMetrix,which led to EF underestimation.

Quantitative Analysis of Myocaridal Perfusion in Rabbits by Tansthoracic Real-time Myocardial Contrast Echocardiography

To evaluate the feasibility of real-time myocardial contrast echocardiography （RTMCE） by quantitative analysis of myocardial perfusion in rabbits, transthoracic RTMCE was performed in 10 healthy rabbits by using continuous infusion of SonoVue into the auricular vein. The short axis view at the papillary muscle level was obtained. The duration of the time that the contrast took to appear in right heart, left heart and myocardium was recorded. The regional myocardial signal intensity （SI） versus re-filling time plots were fitted to an exponential function： y（t） =A（1–e–β（t–t0）） ＋ C, where y is SI at any given time, A is the SI plateau that reflects myocardial blood volume, and β is the slope of the refilling curve that reflects myocardial microbubble velocity. The A, β and A×β values at different infusion rate of SonoVue were analyzed and the A, β and A×β values in each segment in the short axis view at the papillary muscle level were compared. All the animal experiments were successful and high-quality im-ages were obtained. The best intravenous infusion rate for SonoVue was 30 mL/h. The contrast appeared in right heart, left heart and myocardium at 7.5±2.2 s, 9.1±2.4 s and 12.2±1.6 s respectively. After 16.6±2.3s, myocardial opacification reached a steady state. The mean A, β and A×β value in the short axis view at the papillary muscle level were 9.8±3.0 dB, 1.4±0.5 s-1 and 13.5±3.6 dB×s-1 respectively. A, β and A×β values showed no significant differences among 6 segments. It was suggested that RTMCE was feasible for quantitative analysis of myocardial perfusion in rabbits. It provides a non-invasive method to evaluate the myocardial perfusion in rabbit disease models.

Myocardial perfusion imaging in patients with a recent, normal exercise test

AIM: To investigate the added value of myocardial perfusion scintigraphy imaging (MPI) in consecutive patients with suspected coronary artery disease (CAD) and a recent, normal exercise electrocardiography (ECG). METHODS: This study was a retrospective analysis of consecutive patients referred for MPI during a 2-year period from 2006-2007 at one clinic. All eligible patients were suspected of suffering from CAD, and had performed a satisfactory bicycle exercise test (i.e. , peak heart rate > 85% of the expected, age-predicted maximum) within 6 mo of referral, their exercise ECG was had no signs of ischemia, there was no exercise-limiting angina, and no cardiac events occurred between the exercise test and referral. The patients subsequently underwent a standard 2-d, stress-rest exercise MPI. Ischemia was defined based on visual scoring supported by quantitative segmental analysis (i.e. , sum of stress score > 3). The results of cardiac catheterizationwere analyzed, and clinical follow up was performed by review of electronic medical files. RESULTS: A total of 56 patients fulfilled the eligibility criteria. Most patients had a low or intermediate ATPⅢ pretest risk of CAD (6 patients had a high pre-test risk). The referral exercise test showed a mean Duke score of 5 (range: 2 to 11), which translated to a low postexercise risk in 66% and intermediate risk in 34%. A total of seven patients were reported with ischemia by MPI. Three of these patients had high ATPⅢ pre-test risk scores. Six of these seven patients underwent cardiac catheterization, which showed significant stenosis in one patient with a high pre-test risk of CAD, and indeterminate lesions in three patients (two of whom had high pre-test risk scores). With MPI as a gate keeper for catheterization, no significant, epicardial stenosis was observed in any of the 50 patients (0%, 95% confidence interval 0.0 to 7.1) with low to intermediate pre-test risk of CAD and a negative exercise test. No cardiac events occurred in any patients within a median follow up period of > 1200 d. CONCLUSION: The added diagnostic value of MPI in patients with low or intermediate risk of CAD and a recent, normal exercise test is marginal.

Contribution of Myocardial Perfusion’s Tomoscintigraphy in the Management of Coronarian Disease in Senegal: About 42 Cases

The aim of the study was to evaluate the contribution to moscintigraphy of myocardial perfusion (TSMP) with 99mTc-sestamibi in the management of suspected or known coronary patients’s population. It included 42 patients with an average age of 57.02 &plusmn;9.77 years with extremes ranging from 36 to 77 years. The pre-test probability in 38 patients was high in 7 patients (18.42%), intermediate in 29 patients (76.31%) and low in 2 patients (5.26%). Patients with a high pre-test probability had a positive scintigraphy. Among the 26 patients who underwent transthoracic ultrasound (TTU), 10 with normal kinetics on trans-thoracic ultrasound (TTU) had positive scintigraphy. For 16 patients with TTU abnormalities, 6 had negative scintigraphy and 10 had positive scintigraphy. The TSMP was positive for 28 patients (66.66%). Among these patients, 16 had pure ischemia, 57.14% (16/28), 7 pure necrosis (25%), and 5 both necrosis and ischemia. Myocardial perfusion scintigraphy remains a very contributory consideration in the management of coronary disease. This is synchronized with the electrocardiogram (ECG) and is an important diagnostic and prognostic tool for coronary artery disease. It also provides a good indication of coronary angiography.

Comparison of myocardial perfusion scintigraphy and computed tomography (CT) angiography based on conventional coronary angiography

Coronary artery disease is one of the most common and important health problems in the world. Early diagnosis of this disease is very important to treat before severe myocardial damage occurred. Myocardial perfusion scintigraphy (MPS) and computed tomography coronary angiography (CTCA) which evaluates regional myocardial perfusion and coronary arteries, respectively, are reliable and non-invasive methods in terms of coronary artery disease. In this study we aimed to compare MPS and CTCA based on conventional coronary angiography (CCA). Totally 60 patients were included in the study. CCA and MPS were performed to 30 patients;CCA and CTCA were performed to the rest of the patients (30 patients). Lesions were classified as mild, moderate and severe in these imaging methods. MPS and CTCA were compared with CCA by using chi-square and Fisher’s exact test. MPS and CTCA’s p values were found for left anterior descending artery (LAD) p: 0, p: 0.271;for circumflex artery (Cx) p: 0.256, p: 0.08 and for right coronary artery (RCA) p: 0.033, p: 0.271, respectively. Furthermore MPS and CTCA’s sensitivity, specificity, accuracy, positive predictive value and negative predictive value were calculated 81% to 87%;70% to 49%;73% to 72%;54% to 72%;90% to 71%, respectively. CCA results were found more concordant with MPS for LAD and RCA lesions and more concordant with CTCA for Cx lesions. It was also found that positive predictive value of MPS and negative predictive value of CTCA were significantly higher than the others. As a result, MPS and CTCA were suggested as complementary techniques for the diagnosis of coronary artery disease, not as alternatives to each other.

Differential Impact of Appropriate Use Criteria on the Association between Age and Abnormal Stress Myocardial Perfusion SPECT

Background:The diagnostic and prognostic value of appropriate use criteria(AUC)for coronary artery disease(CAD)is well established.Whether the diagnostic yield of AUC for predicting CAD is preserved among the elderly is not known.Methods:We analyzed a multisite prospective cohort of 1511 consecutive patients(age 59±13 years,57%males)who underwent outpatient,community-based single-photon emission computed tomography(SPECT)myocardial perfusion imaging(MPI).Appropriateness of the studies was determined on the basis of the 2013 multimodality AUC for detection and risk assessment of stable ischemic heart disease.Abnormal SPECT MPI was defi ned by either a summed stress score of 4 or greater or a summed difference score of 2 or greater.Results:Abnormal SPECT MPI was present in 190 patients(12.5%),while ischemia on MPI alone was present in 122 patients(8%).In multivariate logistic regression analysis,age of 60 years or greater,male sex,hypertension,diabetes mellitus,and known CAD were independent predictors of abnormal SPET MPI,while appropriate indication for testing was not.Age of 60 years or greater was also an independent predictor of inducible myocardial ischemia,while appropriate indication for testing was not.Among the elderly(≥60 years),regardless of appropriateness of testing,there was no difference in the prevalence of abnormal SPECT(19 vs.14%,P=0.14)or prevalence of SPECT ischemia(11 vs.11%,P=1.00).Among younger patients,however,appropriate testing predicted a greater prevalence of abnormal SPECT(12 vs.7%,P=0.013).Conclusion:In this multisite cohort,testing based on AUC did not discriminate the risk of abnormal SPECT MPI among the elderly.Caution is advised when relying on AUC for referral of elderly patients for SPECT MPI.

Assessment of the Patient Movement for Lesion during Myocardial Perfusion SPECT Imaging by Cardiac Phantom

Movement of the patient during myocardial perfusion SPECT leads to some artifacts that make the interpretation difficult. In this study, myocardial perfusion imaging protocol was performed on a cardiac phantom and SPECT was performed by simulating patient movements. A lesion model with dimensions of 1.2 × 2 × 2 cm was created on the inferoseptal wall of the cardiac phantom. Imaging was done in circular orbits in 64 × 64 matrix and step and shoot mode. First set of images taken with no movement was referred as the reference image. During imaging, patient movement was simulated by moving the phantom in ±X and ±Y directions between the frames starting from 8th frame to 16th frame. At the end of imaging, Bull’s eye maps of images with movement were com-pared with Bull’s eye maps of reference images. Bull’s eye maps were evaluated by an experienced nuclear medicine physician. Shifting patient’s movement in all directions by ±1 and ±2 cm, dis-placed the localization of the lesion mildly and this did not hamper the evaluation. However, movements of ±3 or ±4 cm resulted in artifacts which in turn caused partial or no visualization of the lesion. In motion corrected images, the lesion could be evaluated in ±1 and ±2 cm movements while lesion could not be evaluated in ±3 and ±4 cm movements. As a result, movement greater than ±3 cm causes significant image artifacts and this should be considered as a potential source of error in myocardial perfusion studies.

A quantitative assessment of heart phantom motion and its effect on myocardial perfusion SPECT images

In order to study the image characteristics of motion artifacts and todetermine the relations of motion artifacts with varied motion types, and the inag-ing timings, frames, distances and directions during SPECT acquisition, a myocardialphantom filled with pertechnetate solution was used to simulate the patient motion.In nonreturning pattern, the simulation motion was timed at the 0°, -45° and -90°positions during the rotation of the detector over a 180° arc from +45° right antcrioroblique to -135° left posterior oblique. Simulation motion was performed by movingthe phantom +5mm, ±-10mm and +20mm along X- (from left to right), Y- (fromhead to caudal) and Z-axis (from back to ventral) respectively. In returning patternthe acquired 30 projections were divided into three equal parts. The simulation motionwas timed at the middle 1-7 projections of each part and performed by moving thephantom +5, ±10, ±15, ±20, ±25, ±30 and ±50 mm along X-, Y- and Z-axis respec-tively. Each image was compared with normal image and assessed by three experiencedobservers without knowledge of the phantom motion. Logistic regression analysis wasused to determine the relationship of motion artifacts with the affecting factors. Nosignificant artifacts can be found when the phantom was moved slightly, no matterwhich motion pattern, direction and timing were taken. The characteristics of motionartifacts showed a radioactive marker dot in inferior wall firstly when the phantomwas moved along X-axis. Septal and lateral wall became "hot" symmetrically whenthe phantom was moved along Y-axis. And nodular hot could be found in anteriorwall when the phantom was moved along Z-axis. At last the "lumpy" and "defect"areas existed alternately and formed a triangle respectively. The presence of motionartifacts was related to motion directions, distance and affected frames, but was in-dependent of motion timing. The characteristics of motion artifacts could be foundwhen the phantom was moved along different axis. Motion distance contributed moreto the appearance of motion artifacts than other related factors, this was especiallyclear when motion was along Y-axis.

Rest Thallium-201/Stress Technetium-99m Sestamibi Dual-Isotope Myocardial Perfusion Single-Photon Emission Computed Tomography in Detecting of Chronic Coronary Artery Disease

To investigate diagnostic accuracy of 2-hour protocol of rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT in chronic coronary artery disease. Sixty-seven patients with suspected CAD were enrolled in the prospective study. All patients underwent myocardial perfusion scintigraphy in SPECT with dual isotopes of T1-201 and dipyridamole stress Tc-99m sestamibi. Rest and stress imaging protocol were performed in 2 hours by dose of 3 mCi TI-201 and 25 mCi Tc-99m sestamibi. The acquisition parameters includes LEHR collimator, energy peak of 72 and 167 keV for T1-201 and 140 keV for Tc-99m, 180-degree rotation from RAO to LPO, matrix size 64x64, and 25second/frame/64 frames. The 20-segment model of left ventricle was used in automatic quantitation software. Coronary angiography was used as gold standard. CAD was defined as 50% of lumen stenosis on coronary angiography. Rest TI-201/stress tc-99m sestamibi dual-isotope SPECT demonstrated a sensitivity of 94.59% and specificity of 70%, positive predictive value of 79.54% and negative predictive value of 91.3% in detection of coronary artery disease. Sensitivity and specificity for detecting multi-vessel coronary artery disease were 82.75% and 81.57% for the left anterior descending, 77.77% and 91.83% for left circumflex and 94.11% and 82% for right coronary artery. 2-hour protocol of rest thallium-201/stress technetium-99m sestamibi dual-isotope myocardial perfusion SPECT has high sensitivity, specificity, positive predictive value and negative predictive value in detecting chronic coronary artery disease with greater than 50% stenosis assessed by coronary angiography Moreover, this imaging protocol gives high imaging quality, time-saving and convenience.

Predicting patient response to cardiac resynchronization therapy by gated SPECT myocardial perfusion imaging

Introduction Heart failure(HF)is widely prevalent(> 6 million cases)and rapidly growing(> 0.6 million new cases annually)in the United States.Although the prevalence of HF in China is less than that in the United States,the total number of HF patients in China exceeds 4 million.

Myocardial ischemia is a key factor in the management of stable coronary artery disease

Previous studies demonstrated that coronary revascularization,especially percutaneous coronary intervention(PCI),does not significantly decrease the incidence of cardiac death or myocardial infarction in patients with stable coronary artery disease.Many studies using myocardial perfusion imaging(MPI) showed that,for patients with moderate to severe ischemia,revascularization is the preferred therapy for survival benefit,whereas for patients with no to mild ischemia,medical therapy is the main choice,and revascularization is associated with increased mortality.There is some evidence that revascularization in patients with no or mild ischemia is likely to result in worsened ischemia,which is associated with increased mortality.Studies using fractional flow reserve(FFR) demonstrate that ischemia-guided PCI is superior to angiography-guided PCI,and the presence of ischemia is the key to decisionmaking for PCI.Complementary use of noninvasive MPI and invasive FFR would be important to compensate for each method's limitations.Recent studies of appropriateness criteria showed that,although PCI in the acute setting and coronary bypass surgery are properly performed in most patients,PCI in the non-acute set-ting is often inappropriate,and stress testing to identify myocardial ischemia is performed in less than half of patients.Also,some studies suggested that revascularization in an inappropriate setting is not associated with improved prognosis.Taken together,the presence and the extent of myocardial ischemia is a key factor in the management of patients with stable coronary artery disease,and coronary revascularization in the absence of myocardial ischemia is associated with worsened prognosis.