Extent Of Myocardial Ischemia Research Articles

Should We Continue to Consider Extent of Ischemic Myocardium in Chronic Coronary Syndromes?

Should We Continue to Consider Extent of Ischemic Myocardium in Chronic Coronary Syndromes?

691 RELATION BETWEEN HIGH-SENSITIVITY TROPONIN I SERUM LEVELS AND MYOCARDIAL ISCHEMIA IN PATIENTS WITH SUSPECTED CHRONIC CORONARY SYNDROME: THE RESET-MI STUDY

Abstract Background Although the detection of a rise and/or fall pattern of cardiac troponin (cTn) serum levels in presence of a clinical context of acute myocardial ischemia, represents the main criterion for the diagnosis of acute myocardial infarction (AMI), troponins may increase in various conditions of myocardial injury different from ischemic myocardial necrosis or simply following myocardial ischemia, in the absence of cell necrosis. Some studies found that troponins also increase after physical exertion and other types of stressful stimuli in the absence of obstructive CAD and myocardial ischemia. No previous study, however, investigated the relation between cTn serum levels and the extent of myocardial ischemia in patients with a suspect of CCS. Methods We prospectively enrolled consecutive patients undergoing an elective stress myocardial perfusion scintigraphy (MPS) because of a clinical suspicion of obstructive coronary artery disease (CAD). Patients were divided into 3 groups based on the evidence and degree of stress-induced MI at MPS: 1) group 1, no MI (≤4%); 2) group 2, mild MI (5-10%); 3) group 3, moderate-to-severe MI (≥10%). High sensitivity (hs)-cTnI was measured immediately before (T0) and 1 hour (T1) and 4 hours (T2) after the stress test. A successive evaluation of patients was performed at 24 months. Results One-hundred consecutive patients (64 males; age 65.5±9.5 years) were enrolled in the study. Serum hs-cTnI concentrations significantly increased after MPS, compared to baseline, in the whole population, from (median, interquartile range) 3.9 (2.5-6.1) ng/L at T0, to 4.2 (2.8-7.3) ng/L at T1 (p<0.001) and 6.7 (3.8-14.1) ng/L at T2 (p<0.001 vs. both T0 and T1). The increase in hs-cTnI did not significantly differ between the 3 groups (p=0.35). Heart rate achieved during the test was the strongest determinant of cTnI increase (p < 0.001). No major adverse cardiac event occurred during follow-up. Only 12 patients (12%) underwent coronary revascularization, whereas angina episodes were reported by 23 patients (23%). There were no significant differences in hs-cTnI increase after the stress test between patients with clinical events at follow-up compared with those who did not report myocardial revascularization or angina recurrence (p=0.21). Conclusions In patients with suspected CAD, stress MPS induces an increase of cTnI that is independent of the induction and the extent of myocardial ischemia and is mainly related to myocardial work, as indicated by HR achieved during the test.

Plasma hydroxyanthranilic acid as a predictor of stress induced myocardial ischemia in non-obstructive coronary artery disease

Abstract Background The tryptophan catabolite hydroxyanthranilic acid (HAA) has potent immunomodulatory and vasoactive effects. HAA is also a precursor in the synthesis of nicotinamide adenine dinucleotide (NAD), a crucial cofactor in energy-metabolism. We have previously demonstrated that elevated plasma HAA predicted risk of myocardial infarction. Purpose To explore if plasma HAA is associated with stress induced myocardial ischemia in non-obstructive coronary artery disease (CAD). Methods In 132 patients with chest pain and non-obstructive CAD by coronary computed tomography angiography (CCTA), plasma HAA was analyzed by gas chromatography tandem mass spectrometry. All participants underwent myocardial contrast stress echocardiography. Myocardial ischemia was assessed as delayed contrast replenishment at peak dobutamine stress during real-time low mechanical index imaging and destruction replenishment. The extent of ischemia was defined as the number of segments with delayed contrast enhancement using a 17-segment left ventricular model. Associations of plasma HAA with myocardial ischemia was evaluated in a multivariate adjusted linear regression model. Results Mean (SD) age at inclusion was 63 (8) years and 56% were women. At CCTA, the median (25th, 75th percentile) coronary artery calcium (CAC) score was 42 (13–107) Agatston units, whereas the mean (SD) segment involvement score (SIS) was 2.6 (1.6). Myocardial ischemia was found in 52% of patients with on average 5 (3) ischemic segments per patient. Serum HAA did not correlate with the CAC score or SIS (p>0.29). After multivariate adjustment including age, sex, body mass index, systolic blood pressure, diabetes, current smoking, and LDL cholesterol, the odds ratio and 95% confidence interval for myocardial ischemia was 1.55 (1.04–2.32), P=0.03, per SD increment of plasma HAA levels (log transformed). Plasma HAA was also associated with the extent of myocardial ischemia with a multivariate adjusted β of 0.26, P=0.004. Conclusion Plasma HAA is associated with the extent of myocardial ischemia in non-obstructive CAD. Potential roles of this metabolite in atherogenesis, vascular dysfunction and as a predictor of myocardial ischemia should be further elucidated. Funding Acknowledgement Type of funding sources: Public hospital(s). Main funding source(s): Western Norway Regional Health Authority

Myocardial revascularization : Controversy over noninvasive and invasive detection of ischemia

With some exceptions, myocardial revascularization in patients with chronic coronary syndrome (CCS) is generally decided on the basis of the extent of myocardial ischemia. Current data indicate that apatient will benefit from revascularization if ischemia is present in more than 10% of the myocardium. Accordingly, all patients presenting with CCS should undergo anoninvasive ischemia test that can answer this question before diagnostic coronary angiography. In order to be able to make arecommendation for revascularization based on scientific data even in those patients who previously had no clear evidence of ischemia, e.g., because of discrepant findings, measurement of the hemodynamic significance of coronary stenoses with alumen diameter reduction ≥ 50% should be performed during coronary angiography. Adecision to revascularize based on hemodynamic significance was shown to be beneficial to patients in several studies.

Incremental value of volumetric quantification for myocardial perfusion imaging by computed tomography.

The study aimed to compare a novel ischemic volume quantification method based on dynamic computed tomography perfusion (VOL CTP) with other CT-based imaging modalities for revascularization prediction. In this prospective study, 53 (25 females, 63.5 [8.5] years old) consecutive symptomatic patients with 50%-90% coronary artery stenosis (n ≥1) on coronary computed tomography angiography underwent computed-tomography-derived fractional flow reserve (CT-FFR) analysis and dynamic CTP. We calculated the percentage of myocardial ischemia on the CTP-derived images. A 10% cut-off was used to define functionally significant ischemia. The outcomes include coronary revas-cularization during the follow-up of 2.5 (interquartile range, 1.4-2.8) years. Physicians were blinded to the results of CTP and CT-FFR. Of the 53 patients in the study (68 arteries with 50%-90% stenosis), 16 underwent revascularization (12 elective, 4 event-driven). In the CTP quantitative analysis, 26 patients had ischemia. Overall, 18 patients had ischemia ≥10% on volumetric ischemia quantification based on dynamic computed tomography perfusion (VOL CTP), and 28 patients had CT-FFR <0.8. VOL CTP, standard CTP, CT-FFR, and computed tomography coronary angiography (CTA) ≥70% performed well for the prediction of total revascularization. Area under the curve was 0.973 vs. 0.865, vs. 0.793, vs. 0.668, respectively. The VOL CTP with ≥10% cut-off was superior to the CT-FFR, standard CTP, and CTA ≥70% (P <0.001; P = 0.002 and P <0.001 respectively). VOL CTP quantification is feasible and adds important, actionable information to that provided by standard CTP or CT-FFR in patients with 50%-90% coronary artery stenosis.

Patients’ perception of health status and ischaemic burden in stable coronary artery disease

Background: Angina pectoris, the main manifestation of coronary artery disease has an unfavorable impact on quality of life. The aim of this study was to assess Health-Related Quality Of Life (HRQoL) in patients with Stable Coronary Artery Disease (SCAD) and to explore possible relationships between HRQoL and the risk factors for ischaemic heart disease, the Canadian Cardiovascular Society (CCS) angina severity class, and the extent of myocardial ischaemia on Single Photon Emission Computed Tomography Myocardial Perfusion Imaging (SPECT-MPI). Methods: HRQoL was assessed with the use of two generic questionnaires, EQ-5D-3L and SF-36v2 in one hundred consecutive patients with SCAD. Results: Most of the patients presented problems on the dimensions of mobility, pain/discomfort, and anxiety/depression of the EQ5D questionnaire. The EQ-VAS score was 61.96 ± 20.99, and the mean EQ-5D index value was 0.54 ± 0.31. The mean scores of the Physical Component Summary and the Mental Component Summary of the SF-36 questionnaire were 43.49 and 41.01 respectively. Higher CCS angina class, female gender and poor physical activity were significantly correlated with worse HRQoL. No statistically significant association was detected between HRQoL and the extent of ischaemia on myocardial perfusion imaging. Conclusions: Patients with SCAD have an impaired HRQoL, which can be reliably assessed by generic HRQoL questionnaires. Angina severity could be used as a surrogate of HRQoL, but individual perception of health status should be measured independently of the amount of ischaemiaon cardiac perfusion scintigraphy Keywords: health related quality of life; myocardial perfusion imaging; coronary artery disease.

Serial change in perfusion\u2013metabolism mismatch after coronary artery bypass grafting

ObjectiveMyocardial ischemia is known to suppress fatty acid metabolism and favor glucose metabolism. However, changes in myocardial metabolism after coronary revascularization are not fully elucidated.MethodsThirty-eight patients with coronary artery disease were retrospectively enrolled. These patients had undergone stress perfusion single photon emission computed tomography (SPECT) and 123I-BMIPP SPECT in both the short-term (6.4 ± 4.7 months) and mid-term (29.9 ± 7.2 months) after isolated coronary artery bypass grafting. Tracer uptake was graded using a 17-segment, 5-point scoring model. Serial changes in SRS (summed rest score), SDS (summed difference score), the BMIPP score (total defect score of BMIPP), and the mismatch score (BMIPP score–SRS) were evaluated. In addition, persistent perfusion–metabolism mismatch (PM) was defined as mismatch score minus SDS of 3 or more during the mid-term postoperative period. The clinical parameters associated with PM were examined.ResultsFrom short- to mid-term postoperative period, the extent of infarcted myocardium (SRS) did not change significantly (7.8 ± 8.0 to 7.1 ± 7.0, P = 0.117). The extent of ischemic myocardium (SDS), the BMIPP score and the mismatch score, which reflects perfusion–metabolism mismatch, were significantly improved (2.0 ± 2.8 to 0.7 ± 1.0, P = 0.010; 12.2 ± 9.0 to 9.5 ± 7.9, P < 0.001; 4.4 ± 3.7 to 2.5 ± 2.6, P < 0.001; respectively). Remarkably, perfusion–metabolism mismatch persisted in 13 patients (34%) even in the mid-term postoperative period. eGFR and SYNTAX score were independent predictors of persistent perfusion–metabolic mismatch in multivariable analysis (OR = 0.951, 95% CI 0.898–0.985, P = 0.010 and OR = 1.126, 95% CI 1.011–1.254, P = 0.031, respectively). The mismatch score both in the short- and mid-term significantly correlated with SYNTAX score (r = 0.400 and r = 0.472, respectively).ConclusionsFatty acid metabolism disturbance improved from short- to mid-term postoperative period in patients with successful reperfusion by coronary artery bypass grafting. However, in patients with severe atherosclerosis, impaired fatty acid metabolism was sustained until the mid-term postoperative period, even though ischemia had resolved.

Myocardial Ischemia During Off-Pump Coronary Artery Bypass Grafting – A Clinical Study

Objective: To evaluate relation among trans-esophageal echocardiography (TEE), biochemical and hemodynamic parameters which could possibly help in early detection of myocardial ischemia. Design: Prospective observational, single centre study. Participants: Patients diagnosed with coronary artery triple vessel disease undergoing Off-pump Coronary Artery Bypass Grafting (OPCAB). Results: Statistically significant changes in Coronary Sinus (CS) pH and lactate levels were observed during lateral wall grafting, as well as the highest proportion of new regional wall motion abnormalities observed which signify the presence of a substantial level of myocardial ischemia during this time. We found a significant rise in HR (Heart Rate) as well as CS lactate following lateral wall grafting which correlated with the other parameters indicating substantial ischemia occurring during grafting of that territory. Maximum lactate clearance was found during anterior wall grafting and minimum after inferior wall grafting. This signifies that maximum lactate accumulates after anterior wall grafting, signifying greater extent of myocardial ischemia. Statistically significant rise in (CVP/RAP) (central venous pressure, right atrial pressure was noted) during grafting of all coronary territories, but the maximal rise was seen at the end of lateral wall grafting, followed by grafting of posterior basal wall. Conclusions: Biochemical changes in form of rise in lactate and fall in CS pH doesn’t occur in absence of obvious hemodynamic derangements. Therefore, it is difficult to detect myocardial ischemia before any hemodynamic instability.

Rekanalisation chronischer Koronarverschlüsse

Recanalisation of chronic total coronary occlusions - what is the evidence and which patients will benefit? Abstract. Continuous improvement of recanalisation techniques and newer device technologies significantly improved the success of revascularisation in percutaneous coronary intervention (PCI) of chronic total occluded coronary arteries (CTO) in the past few years. The best documented clinical benefit of CTO-PCI is symptom control, based on a reduction of myocardial ischemia. In contrast, there is still an ongoing controversial debate regarding the prognostic benefit of successful CTO-PCI shown in several observational studies. Therefore, the indication for CTO-PCI is primarily based on patients' symptoms and the extent of myocardial ischemia. The risk / benefit ratio for the individual patient has to be estimated from technical complexity of the CTO lesion, the extent of the coronary artery disease and the ventricular function. Recanalisation strategy should be escalating, as most of the CTOs can be successfully recanalised with standard antegrade recanalisation techniques. With the implementation of retrograde CTO techniques, the likelihood for recanalisation success is very high (> 90 %) even in complex anatomies, combined with low complication rates in specialised centers. According to the operator's expertise a complete catheter-based revascularisation can be achieved nowadays even in patients with CTO and coronary multi-vessel disease.

Stress CMR in Known or Suspected CAD: Diagnostic and Prognostic Role.

The recently published 2019 guidelines on chronic coronary syndromes (CCS) focus on the need for noninvasive imaging modalities to accurately establish the diagnosis of coronary artery disease (CAD) and assess the risk of clinical scenario occurrence. Appropriate patient management should rely on controlling symptoms, improving prognosis, and guiding each therapeutic strategy as well as monitoring disease progress. Among the noninvasive imaging modalities, cardiovascular magnetic resonance (CMR) has gained broad acceptance in past years due to its unique features in providing a complete assessment of CAD through data on cardiac anatomy and function and myocardial viability, with high spatial and temporal resolution and without ionizing radiation. In detail, evaluation of the presence and extent of myocardial ischemia through stress CMR (S-CMR) has shown a high rule-in power in detecting functionally significant coronary artery stenosis in patients suspected of CCS. Moreover, S-CMR technique may add significant prognostic value, as demonstrated by different studies which have progressively evidenced the valuable power of this multiparametric imaging modality in predicting adverse cardiac events. The latest scientific progress supports a greater expansion of S-CMR with improvement of quantitative myocardial perfusion analysis, myocardial strain, and native mapping within the same examination. Although further study is warranted, these techniques, which are currently mostly restricted to the research field, are likely to become increasingly prevalent in the clinical setting with the scope of increasing accuracy in the selection of patients to be sent to invasive revascularization. This review investigates the diagnostic and prognostic role of S-CMR in the context of CAD, by analysing a strong, long-standing, scientific evidence together with an appraisal of new advanced techniques which may potentially enrich CAD management in the next future.

Early post-stress decrease in cardiac performance by impedance cardiography and its relationship to the severity and extent of ischemia by myocardial perfusion imaging

BackgroundWhile single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is a well-established noninvasive procedure for the evaluation of patients with coronary artery disease (CAD), it is unable to detect the presence of, or underestimates the extent of CAD in certain patients. We aimed to show that a bio-impedance device can detect early post-stress changes in several hemodynamic parameters, thereby serving as a potential marker for the presence of significant ischemia.MethodsProspectively enrolled patients, referred to our Medical Center for clinically-indicated MPI, underwent testing using a Non-Invasive Cardiac System (NICaS) before and immediately after exercise. The differences between rest and stress hemodynamic parameters were compared with the severity and extent of myocardial ischemia by MPI. The study included 198 patients; mean age was 62 years, 26% were women, 54% had hypertension, and 29% diabetes mellitus. Of them, 188 patients had ≤10%, and 10 had > 10% of myocardial ischemia.ResultsIn the first group, there was a significantly greater increase in post-exercise stroke index, stroke work index, cardiac index and cardiac power index (19.2, 29.1, 90.5 and 107%, respectively) compared with the second group (− 2.7, 3.8, 43.7 and 53.5%, respectively), as well as a significantly greater decrease in total peripheral resistance index (− 38.7% compared with − 16.3%), with corresponding p values of 0.015, 0.017, 0.040, 0.016, and < 0.001, respectively.ConclusionsOur data suggest that immediate post-stress changes in several hemodynamic parameters, detected by the NICaS, can be used as an important adjunct to SPECT MPI for the early detection of myocardial ischemia.

P3354Papillary muscle ischemia and global myocardial flow reserve: assessment by high-resolution cine imaging of 13N ammonia PET

Abstract Purpose Papillary muscle ischemia (PMI) is caused by micro-vessels' occlusion in the broad endocardium because papillary muscle perfusion is supply from micro-vessels of peripheral coronary arteries and is easy to fail by the increase in peripheral vascular resistance. However, the clinical significant is not understood because PMI could not be detected by existing perfusion imaging such as SPECT and MRI. We propose the detection method of PMI using 13N-ammonia PET (NH3-PET), and investigate the association with the global myocardial flow reserve (Global-MFR) reflecting coronary microvascular dysfunction. Methods Data of adenosine-stress NH3-PET for consecutive 260 patients with coronary artery disease (CAD) or suspected CAD was retrospectively analyzed. Using high-resolution cine imaging derived from NH3-PET, PMI was defined as the absence of the PM accumulation at stress conditions. Myocardial flow was generated from the time activity curve of left ventricle input and myocardial uptake using 3-compartment model and the first 2 minutes' dataset of list mode images. Global-MFR was calculated by stress to rest flow ratio. Summed stress score (SSS) was used as an estimate of the extent of myocardial ischemia. 150 out of 260 patients (58%) with SSS ≥4 or with the past history of coronary artery diseases were classified as ischemic group, and 110 patients (42%) with SSS&lt;4 were classified as non-ischemic group. Results PMI was seen in 68 of 260 patients (26.6%). The frequency of PMI was higher in the ischemic group than the non-ischemic group (37.8% vs. 10.1%, p&lt;0.0001). Global-MFR was significantly lower in patients with PMI than those without (1.87±0.55 vs. 2.39±0.80, p&lt;0.0001). In both ischemic and non-ischemic group, global-MFR was significantly reduced in patients with PMI. (Ischemic group: 1.83±0.56 vs. 2.12±0.52, p=0.0043, Non-ischemic group: 2.06±0.45 vs. 2.63±0.91, p=0.040). Typical case of PMI Conclusion High-resolution cine imaging derived from NH3-PET makes it possible to detect PMI in about a quarter of patients with CAD or suspected CAD. PMI associates with reduced Global-MFR regardless of the presence of myocardial ischemia, suggesting that PMI is an important sign of early ischemia confined to the papillary muscle or the broad microvascular injury.

Relationship of left ventricular end‐diastolic pressure with extent of myocardial ischemia, myocardial salvage and long‐term outcome in patients with ST‐segment elevation myocardial infarction

We aimed to assess the association of left ventricular end-diastolic pressure (LVEDP) with myocardial salvage and long-term mortality in ST-segment elevation myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention (PCI). The association of LVEDP with myocardial salvage or long-term mortality in patients with STEMI has not been investigated. This study included 1,312 patients with STEMI undergoing primary PCI between 2002 and 2007. LVEDP was measured at the time of intervention. Patients were divided into three groups: a group with LVEDP in the 1st tertile (LVEDP, 4-19 mmHg; n = 496), a group with LVEDP in the 2nd tertile (LVEDP >19-24 mmHg; n = 410) and a group with LVEDP in the 3rd tertile (LVEDP >24-45 mmHg; n = 406). The primary outcome was 8-year cardiac mortality. The primary outcome (cardiac deaths) occurred in 114 patients. Deaths occurred in 26 (7.9%), 36 (11.5%), and 52 (16.4%) patients with LVEDP in the 1st to 3rd tertiles, respectively (adjusted hazard ratio = 1.18, 95% confidence interval 1.02-1.36, P = 0.022, for 5 mmHg increment in the LVEDP values). LVEDP correlated with the extent of myocardial ischemia (R = 0.351; P < 0.001). In patients with LVEDP in the 1st to 3rd tertiles, the salvage index (proportion of initial area at risk salvaged) was 0.53 [0.27-0.84], 0.53 [0.28-0.80], and 0.43 [0.18-0.75], respectively (P = 0.012). After adjustment, LVEDP correlated inversely with myocardial salvage (P < 0.001). In patients with STEMI, elevated LVEDP correlated with the extent of myocardial ischemia, reduced myocardial salvage and increased risk of 8-year cardiac mortality.

Impact of Subtended Myocardial Mass Assessed by Coronary Computed Tomographic Angiography-Based Myocardial Segmentation

Although decision-making for revascularization is based on the extent of ischemic myocardium, the prognostic implication of supplying myocardial territories has not yet been studied. To evaluate the clinical impact of the coronary artery-based myocardial segmentation (CAMS)-derived myocardial volume subtended to the poststenotic segment, and to determine clinically relevant coronary lesions, coronary computed tomography angiography, invasive coronary angiography, and preprocedure fractional flow reserve (FFR) data were analyzed in 664 deferred lesions (in 577 patients) and 401 treated lesions (in 369 patients) with drug-eluting stent implantation, respectively. Using CAMS method, the myocardial volume subtended to a stenotic coronary segment (Vsub) was assessed. The primary composites included target vessel-related major adverse cardiac event (MACE) including cardiac death, myocardial infarction, and target vessel revascularization over 3 years. Independent predictors of 3-year MACE in deferred lesions were Vsub (adjusted hazard ratio [HR] 1.02), FFR (adjusted HR per 0.1 = 0.60), and distal reference luminal diameter (adjusted HR 2.04, all p < 0.05). A Vsub ≥ 36.2cc was predictive of MACE in deferred lesions with a sensitivity 72% and a specificity 67% (area under curve 0.71, 95% confidence interval 0.67 to 0.74, p < 0.001). Vsub was not associated with target vessel-related MACE. For the prediction of FFR < 0.80, the area under curve of Vsub/MLD4 > 6.3 was greater than those of angiographic diameter stenosis (0.78 vs 0.69) and minimal luminal diameter (0.78 vs 0.71), (all p < 0.05). CAMS-derived Vsub predicted 3-year clinical outcomes in untreated coronary lesions, and improved the diagnostic performance of angiography-derived parameters to identify ischemia-producing lesions.

Management of cardiogenic shock complicating myocardial infarction.

Up to 10% of acute coronary syndromes are complicated by cardiogenic shock (CS) with contemporary mortality rates of 40-50%. The extent of ischemic myocardium has a profound impact on the initial, in-hospital, and post-discharge management and prognosis in this patient population. Individualized patient risk assessment plays an important role in determining appropriate revascularization, drug treatment with inotropes and vasopressors, mechanical circulatory support, intensive care support of other organ systems, hospital level of care triage, and allocation of clinical resources. This review will outline the underlying causes and diagnostic criteria, pathophysiology, and treatment of CS complicating acute coronary syndromes with a focus on (a) potential therapeutic issues from the perspective an interventional cardiologist, an emergency physician, and an intensive care physician, (b) the type of revascularization, and (c) new therapeutic advancements in pharmacologic and mechanical percutaneous circulatory support.

Correlation of Fractional Flow Reserve With Ischemic Burden Measured by Cardiovascular Magnetic Resonance Perfusion Imaging

Cardiovascular magnetic resonance (CMR) perfusion imaging and fractional flow reserve (FFR) assess myocardial ischemia. FFR measures the pressure loss across a stenosis determining hemodynamic significance but does not assess the area subtended by the stenotic vessel. CMR perfusion imaging measures the extent of myocardial blood flow reduction (=ischemic burden). Both techniques allow for continuous rather than categorical evaluation, but their relationship is poorly understood. This study investigates the relationship between the FFR value and the extent of myocardial ischemia. Forty-nine patients with angina underwent CMR perfusion imaging. FFR was measured in vessels with a visual diameter stenosis >40%. The extent of ischemia for each coronary artery was measured by delineating the perfusion defect on the CMR images and expressing as a percentage of the left ventricular myocardium. The correlation between the extent of ischemia measured by CMR and FFR was good (r = -0.85, p < 0.0005). The mean FFR value was 0.67 ± 0.17, and the mean perfusion defect was 8.9 ± 9.3%. An FFR value of ≥0.75 was not associated with ischemia on CMR. The maximum amount of ischemia (23.0 ± 1.5%) was found at FFR values 0.4 to 0.5. In patients with 1 vessel disease (49%), the mean ischemic burden was 15.3 ± 8.3%. In patients with 2 vessel diseases (18%), the mean ischemic burden was 26.0 ± 12%. Reproducibility for the measurement of ischemic burden was very good with a Kappa coefficient (k = 0.826, p = 0.048). In conclusion, there is good correlation between the FFR value and the amount of myocardial ischemia in the subtended myocardium.

Prognostic impact of location and extent of vessel-related ischemia at myocardial perfusion scintigraphy in patients with or at risk for coronary artery disease

BackgroundMyocardial perfusion scintigraphy (MPS) has an established diagnostic and prognostic role in patients with or at risk for coronary artery disease, with ischemia severity and extent having already been identified as key predictors. Whether this is affected by the location of myocardial ischemia is uncertain. We aimed at comparing the prognostic outlook of patients undergoing MPS according to the site of ischemia. MethodsOur institutional database was queried for subjects undergoing MPS, without myocardial necrosis or recent revascularization. We focused on the prognostic impact of location of vessel-related ischemia (VRI) at MPS, distinguishing four mutually exclusive groups: single-VRI involving left anterior descending (LAD), single-VRI not involving LAD, multi-VRI involving LAD, and multi-VRI not involving LAD. The primary outcome was the long-term (>1 year) rate of death or myocardial infarction (D/MI). ResultsA total of 13,254 patients were included. Moderate or severe VRI occurred in 2,627 (20%) patients. Clinical outcomes were significantly different among the groups of patients with moderate or severe VRI, including death, cardiac death, non-fatal myocardial infarction or their composites (overall P < .001). Specifically, and excluding subjects undergoing revascularization as first follow-up event, D/MI occurred in 8.4% of patients with single-VRI involving LAD, 5.5% of subjects with single-VRI not involving LAD, 16.5% of those with multi-VRI involving LAD, and 7.3% of patients with multi-VRI not involving LAD (overall P < .001). Even at incremental multivariable Cox proportional analysis, hierarchical VRI was independently associated with an increased risk of D/MI [hazard ratio = 1.17 (1.04-1.08) for each class increment, P = .010]. ConclusionsLocation and extent of myocardial ischemia at MPS according to the VRI concept have a hierarchical predictive impact, with multi-VRI involving LAD being significantly and independently more prognostically ominous than other types of VRI.

In-hospital free fatty acids levels predict the severity of myocardial ischemia of acute coronary syndrome.

BackgroundWe aimed to assess whether the levels of FFAs (free fatty acids) in ACS (acute coronary syndrome) patients depend on the extent of myocardial ischemia during the subacute phase of ACS attack.MethodsA total of 892 consecutive CAD (coronary artery disease) subjects undergoing coronary angiography were enrolled. The FFAs contents were measured based on enzymatic assay. The relationship between FFAs and Gensini score and ACS susceptibility was assessed.ResultsIn the overall population, the upper FFAs quartile was accompanied with higher ischemia parameters and increased occurrence of ACS and STEMI (ST-segment elevation myocardial infarction) (P < 0.05). The FFAs concentrations were approximately 1.5-fold higher in ACS than in stable CAD patients, roughly 1.3-fold higher in STEMI than non-STEMI ACS patients and probably 1.3-fold higher in non-STEMI ACS than in stable CAD patients. After adjusted for traditional cardiovascular risk factors, the FFAs level remained a risk factor for a higher Gensini score with more than 40 (P < 0.001) and prevalent ACS (P < 0.001). After adjusted for traditional risk factors, FFAs levels after natural logarithm transformation were associated with hs-CRP and WBC counts in ACS patients. A multiplicative interaction was found between hs-CRP, WBC counts and FFAs in incident ACS and higher Gensini score (P < 0.001).ConclusionsHigher in-hospital levels of FFAs persist and may reflect the severity of ischemia and necrosis during the subacute phase of ACS attack.Electronic supplementary materialThe online version of this article (doi:10.1186/s12872-016-0199-1) contains supplementary material, which is available to authorized users.

DPP-4 inhibition has beneficial effects on the heart after myocardial infarction

AimsDipeptidyl peptidase-4 (DPP-4) inhibitors are reported to have protective effects on various cells but it is unclear how DPP-4 inhibitors have cardioprotective effects. Our aim was to study the mechanisms of cardioprotective effects by DPP-4 inhibition. Methods and resultsC57BL/6 mice and DPP-4 knockout (DPP-4KO) mice were subjected to left coronary artery ligation to produce acute myocardial infarction (MI). C57BL/6 mice were then treated with vehicle or DPP-4 inhibitor. Left ventricular function, infarct size, the number of vessels, and myocardial ischemia were assessed at 5days after MI. The treatment with DPP-4 inhibitor significantly improved cardiac function and decreased the infarct size. DPP-4 inhibitor increased the ratio of endothelial cell numbers to a cardiomyocyte. The extent of myocardial ischemia and the number of TUNEL-positive cells in the border area were significantly decreased by DPP-4 inhibitor. Stromal cell-derived factor-1α (SDF-1α) level in myocardium was significantly increased by DPP-4 inhibitor. Those cardioprotective effects after MI were also recognized in DPP-4KO mice. DPP-4 protein was expressed on rat neonatal cardiomyocytes and DPP-4 inhibitor significantly reduced hypoxia-induced apoptosis in the cardiomyocytes. However, this effect was abolished by the pretreatment with a CXCR4 antagonist or a signal transducer and activator of transcription 3 (STAT3) inhibitor. The beneficial effects of DPP-4 inhibitor on heart failure after MI were abolished by cardiomyocyte-specific deletion of STAT3. ConclusionsDPP-4 inhibition may have direct protective effects on the post-MI heart by inducing an antiapoptotic effect and inhibiting a decrease in vessel number through the SDF-1α/CXCR4-mediated STAT3 signaling pathway.

High Concordance Between Mental Stress-Induced and Adenosine-Induced Myocardial Ischemia Assessed Using SPECT in Heart Failure Patients: Hemodynamic and Biomarker Correlates.

Mental stress can trigger myocardial ischemia, but the prevalence of mental stress-induced ischemia in congestive heart failure (CHF) patients is unknown. We characterized mental stress-induced and adenosine-induced changes in myocardial perfusion and neurohormonal activation in CHF patients with reduced left-ventricular function using SPECT to precisely quantify segment-level myocardial perfusion. Thirty-four coronary artery disease patients (mean age±SD, 62±10 y) with CHF longer than 3 mo and ejection fraction less than 40% underwent both adenosine and mental stress myocardial perfusion SPECT on consecutive days. Mental stress consisted of anger recall (anger-provoking speech) followed by subtraction of serial sevens. The presence and extent of myocardial ischemia was quantified using the conventional 17-segment model. Sixty-eight percent of patients had 1 ischemic segment or more during mental stress and 81% during adenosine. On segment-by-segment analysis, perfusion with mental stress and adenosine were highly correlated. No significant differences were found between any 2 time points for B-type natriuretic peptide, tumor necrosis factor-α, IL-1b, troponin, vascular endothelin growth factor, IL-17a, matrix metallopeptidase-9, or C-reactive protein. However, endothelin-1 and IL-6 increased, and IL-10 decreased, between the stressor and 30 min after stress. Left-ventricular end diastolic dimension was 179±65 mL at rest and increased to 217±71 after mental stress and 229±86 after adenosine (P<0.01 for both). Resting end systolic volume was 129±60 mL at rest and increased to 158±66 after mental stress (P<0.05) and 171±87 after adenosine (P<0.07), with no significant differences between adenosine and mental stress. Ejection fraction was 30±12 at baseline, 29±11 with mental stress, and 28±10 with adenosine (P=not significant). There was high concordance between ischemic perfusion defects induced by adenosine and mental stress, suggesting that mental stress is equivalent to pharmacologic stress in eliciting clinically significant myocardial perfusion defects in CHF patients. Cardiac dilatation suggests clinically important changes with both conditions. Psychosocial stressors during daily life may contribute to the ischemic burden of CHF patients with coronary artery disease.