TCT-635 Unmasking Myocardial Bridge Related Ischemia by Intracoronary Functional Evaluation (original) (raw)
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Unmasking Myocardial Bridge–Related Ischemia by Intracoronary Functional Evaluation
Circulation: Cardiovascular Interventions
A myocardial bridge (MB) is a tunneled segment of an epicardial coronary artery, running deep and for varying lengths in the contest of the myocardial muscle. 1 The presence of this congenital variant, typically involving the left anterior descending (LAD) artery, is traditionally considered a benign condition. Nevertheless, MBs have been related to different clinical conditions, including silent ischemia, stable angina, acute coronary syndromes, Takotsubo cardiomyopathy, and malignant arrhythmias possibly leading to sudden cardiac death. 2-7 Moreover, in clinical practice it is not infrequent to encounter patients with angina, non invasive evidence of myocardial ischemia, and a MB as the only relevant finding at coronary angiography. Thus, an adequate identification of the hemodynamic significance of MBs is important to guide therapeutic approach. Intracoronary functional evaluation of MBs is largely unsettled. The value of fractional flow reserve (FFR), a mean of systolic and diastolic pressure gradients, might be hampered by systolic pressure overshooting and negative systolic pressure gradient (ie, the average coronary pressure distal to the MB is higher than the aortic pressure during systole) caused by the compression of the tunneled coronary artery. 8 On the contrary, the instantaneous wave-free ratio (iFR; Volcano Corporation, San Diego, CA) is a lesion-specific, diastoliconly index, recently validated against FFR for the assessment of fixed coronary artery stenosis to guide percutaneous coronary intervention, 9,10 and might not be affected by the systolic compression of the MB. 1 To date, invasive investigation of MBs by the use of both FFR and iFR at baseline and in stress conditions are restricted to single case reports. 11 Methods Study Population We prospectively enrolled 20 patients with angina and abnormal noninvasive test suggestive of myocardial ischemia, with angiographic and-when available-cardiac computed tomography (CCT) suspicion/evidence of MB. Patients with concomitant significant coronary stenosis (ie, >50% diameter stenosis at quantitative coronary angiography) were excluded from the study. Hypertrophic cardiomyopathy was ruled out by echocardiography in all subjects. All patients gave informed consent to cardiac catheterization and intracoronary functional assessment. The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki and was approved by
The American Journal of Cardiology, 2011
Introduction: Sudden death (SD) is in most cases due to cardiac causes, mainly secondary to ischemic heart disease. However, the angiographic characteristics in SD survivors in the context of an acute coronary syndrome (ACS) remain controversial. The aim of this study was to evaluate the clinical and angiographic characteristics of patients who suffered cardiac arrest during an ACS. Methods: We evaluated 46 patients with SD related to ACS, who were divided into two groups according to their presentation: an ST-elevation myocardial infarction (SD-STEMI) group and a non ST-elevation myocardial infarction (SD-NSTEMI) group. Consecutive STEMI patients without SD served as a double size-matched control group. We compared the clinical and angiographic characteristics and the in-hospital mortality between groups. Results: Patients in the SD-NSTEMI group (n=13) were older and had a higher incidence of hypertension. The left anterior descending coronary artery was the most frequent culprit vessel in all groups. SD-STEMI patients (n=33) had a higher prevalence of proximal coronary culprit segment involvement than did the non-SD STEMI group (75% vs. 36.3%, p<0.001). The SD-NSTEMI group was characterized by multivessel and multi-segment disease. Outcomes were similar for both SD groups. Conclusion: SD in patients with NSTEMI occurred in patients who were older, with more cardiovascular risk factors, diffuse and multivessel coronary disease, complex coronary lesions, and a lower rate of angioplasty success as compared with the STEMI group. SD STEMI patients had a significant higher association with proximal coronary acute occlusion than STEMI patients without SD.
Myocardial Ischemia in Acute Coronary Syndrome: Assessment Using 64-MDCT
American Journal of Roentgenology, 2009
M DCT provides high-quality noninvasive images of the heart and coronary vasculature. The current-generation 64-MDCT scanners allow rapid scanning of the cardiac anatomy, require minimal patient cooperation, and have improved image quality and high diagnostic accuracy for the detection of coronary artery stenosis . In recent studies, investigators have reported that the assessment of coronary plaque and significant stenosis using coronary 64-MDCT had a high accuracy for ruling out acute coronary syndrome (ACS) in patients with acute chest pain and may be useful for improving early triage . However, we acknowledge that the inability to assess coronary artery stenosis in the presence of severe calcification is a limitation of coronary CT angiography even when 64-MDCT is used [1-3]; therefore, coronary CT angiography cannot detect a culprit coronary lesion in a few cases of ACS .
2012
Background-It is known that a significant number of patients experiencing an acute myocardial infarction have normal coronary arteries or nonsignificant coronary disease at coronary angiography (CA). Computed tomography coronary angiography (CTCA) can identify the presence of plaques, even in the absence of significant coronary stenosis. This study evaluated the role of 64-slice CTCA in detecting and characterizing coronary atherosclerosis in these patients. Methods and Results-Consecutive patients with documented acute myocardial infarction but without significant coronary stenosis at CA underwent late gadolinium-enhanced magnetic resonance and CTCA. Only the 50 patients with an area of myocardial infarction identified by late gadolinium-enhanced magnetic resonance were included in the study. All of the coronary segments were assessed for the presence of plaques. CTCA identified 101 plaques against the 41 identified by CA: 61 (60.4%) located in infarct-related arteries (IRAs) and 40 (39.6%) in non-IRAs. In the IRAs, 22 plaques were noncalcified, 17 mixed, and 22 calcified; in the non-IRAs, 5 plaques were noncalcified, 8 mixed, and 27 calcified (Pϭ0.005). Mean plaque area was greater in the IRAs than in the non-IRAs (6.1Ϯ5.4 mm 2 versus 4.2Ϯ2.1 mm 2 ; Pϭ0.03); there was no significant difference in mean percentage stenosis (33.5%Ϯ14.6 versus 31.7%Ϯ12.2; Pϭ0.59), but the mean remodeling index was significantly different (1.25Ϯ0.41 versus 1.08Ϯ0.21; Pϭ0.01). Conclusions-CTCA detects coronary plaques in nonstenotic coronary arteries that are underestimated by CA, and identifies a different distribution of plaque types in IRAs and non-IRAs. It may therefore be valuable for diagnosing coronary atherosclerosis in acute myocardial infarction patients without significant coronary stenosis. (Circulation. 2012;126:3000-3007.
Circulation, 2012
Background-It is known that a significant number of patients experiencing an acute myocardial infarction have normal coronary arteries or nonsignificant coronary disease at coronary angiography (CA). Computed tomography coronary angiography (CTCA) can identify the presence of plaques, even in the absence of significant coronary stenosis. This study evaluated the role of 64-slice CTCA in detecting and characterizing coronary atherosclerosis in these patients. Methods and Results-Consecutive patients with documented acute myocardial infarction but without significant coronary stenosis at CA underwent late gadolinium-enhanced magnetic resonance and CTCA. Only the 50 patients with an area of myocardial infarction identified by late gadolinium-enhanced magnetic resonance were included in the study. All of the coronary segments were assessed for the presence of plaques. CTCA identified 101 plaques against the 41 identified by CA: 61 (60.4%) located in infarct-related arteries (IRAs) and 40 (39.6%) in non-IRAs. In the IRAs, 22 plaques were noncalcified, 17 mixed, and 22 calcified; in the non-IRAs, 5 plaques were noncalcified, 8 mixed, and 27 calcified (Pϭ0.005). Mean plaque area was greater in the IRAs than in the non-IRAs (6.1Ϯ5.4 mm 2 versus 4.2Ϯ2.1 mm 2 ; Pϭ0.03); there was no significant difference in mean percentage stenosis (33.5%Ϯ14.6 versus 31.7%Ϯ12.2; Pϭ0.59), but the mean remodeling index was significantly different (1.25Ϯ0.41 versus 1.08Ϯ0.21; Pϭ0.01). Conclusions-CTCA detects coronary plaques in nonstenotic coronary arteries that are underestimated by CA, and identifies a different distribution of plaque types in IRAs and non-IRAs. It may therefore be valuable for diagnosing coronary atherosclerosis in acute myocardial infarction patients without significant coronary stenosis. (Circulation. 2012;126:3000-3007.)
Impaired Endothelial Function in Patients with Myocardial Bridge
Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques, 2006
Objective: The relationship between myocardial bridging (MB) and ischemic heart disease is still controversial. In this study, we aimed to evaluate the existing atherosclerosis and noninvasive endothelial function of brachial artery in patients with MB. Methods: The present study included 50 patients (group I) who had MB in left anterior descending (LAD) on coronary angiography. All of the coronary artery segments were evaluated by intravascular ultrasound (IVUS). Endothelial function was assessed with measurement of flow-mediated dilatation (FMD) and nitrate-dependent dilatation in the brachial artery. The study also included 30 healthy control subjects (group II). Patients in the group I were further subdivided into two subgroups based on the findings on IVUS: group IA included 20 patients without atherosclerotic lesions and group IB included 30 patients with atherosclerotic coronary artery disease in addition to MB. Results: FMD values were found to be significantly lower in the patients with MB (group I) than in the control (6.4 ± 3% vs 11 ± 4%, P <0.001). In regard to FMD values in subgroups, FMD was 7 ± 2% in the group IA and 5.8 ± 1% in the group IB (P = 0.023). On IVUS, atherosclerotic plaque was found proximal to the bridge in the same coronary artery segment in addition to MB in 75% of the patients in group I (group IB). No atherosclerotic plaque was found in within or distal segments of MB. Conclusion: Endothelial function is impaired in patients with MB and there is an increased tendency for atherosclerosis proximal to the bridge in the patients with MB. Endothelial dysfunction is more severe in the patients with atherosclerosis proximal to the bridge.
Invasive Versus Noninvasive Evaluation of Coronary Artery Disease
JACC: Cardiovascular Imaging, 2008
We sought to compare the diagnostic information obtained from noninvasive characterization of coronary artery disease by using multidetector computed tomography (MDCT) and myocardial perfusion imaging (MPI) and to compare findings with the use of invasive coronary angiography and intravascular ultrasound (IVUS). B A C K G R O U N D Preliminary comparisons have suggested that abnormal myocardial perfusion studies correlate well with significant luminal stenosis on MDCT coronary angiography. However, atherosclerotic coronary lesions may be detectable with the use of MDCT even in the presence of normal myocardial perfusion M E T H O D S We performed MDCT, MPI, and conventional coronary angiography in 70 patients. In addition, IVUS was performed in 53 patients. Quantitative information was obtained from quantitative coronary angiography (QCA) and IVUS assessment of plaque burden and minimal luminal area. R E S U L T S Of 26 patients with an abnormal MPI study, 23 (88%) showed significant stenosis on MDCT.