Assessment of the Relationship between Monocyte to High-Density Lipoprotein Ratio and Myocardial Bridge / Avaliação da Relação entre a Razão de Monócitos para Lipoproteínas de Alta Densidade e a Ponte Miocárdica

Abstract Background: Assessing the monocyte to high-density lipoprotein ratio (MHR) is a new tool for predicting inflamation, which plays a major role in atherosclerosis. Myocardial bridge (MB) is thought to be a benign condition with development of atherosclerosis, particularly at the proximal segment of the brigde. Objective: To evaluate the relationhip between MHR and the presence of MB. Methods: We consecutively scanned patients referred for coronary angiography between January 2013- December 2016, and a total of 160 patients who had a MB and normal coronary artery were enrolled in the study. The patients' angiographic, demographic and clinic characteristics of the patients were reviewed from medical records. Monocytes and HDL-cholesterols were measured via complete blood count. MHR was calculated as the ratio of the absolute monocyte count to the HDL-cholesterol value. MHR values were divided into three tertiles as follows: lower (8.25 ± 1.61), moderate (13.11 ± 1.46), and higher (21.21 ± 4.30) tertile. A p-value of < 0.05 was considered significant. Results: MHR was significantly higher in the MB group compared to the control group with normal coronary arteries. We found the frequency of MB (p = 0.002) to increase as the MHR tertiles rose. The Monocyte-HDL ratio with a cut-point of 13.35 had 59% sensitivity and 65.0% specificity (ROC area under curve: 0.687, 95% CI: 0.606-0.769, p < 0.001) in accurately predicting a MB diagnosis. In the multivariate analysis, MHR (p = 0.013) was found to be a significant independent predictor of the presence of MB, after adjusting for other risk factors. Conclusion: The present study revealed a significant correlation between MHR and MB.

Resumo Fundamento: A avaliação da razão de monócitos para lipoproteínas de alta densidade (MHR, sigla em inglês) é uma nova ferramenta para se prever o processo inflamatório, o qual desempenha um papel importante na aterosclerose. A ponte miocárdica (PM) é considerada uma condição benigna com desenvolvimento de arteriosclerose, particularmente no segmento proximal da ponte. Objetivo: Avaliar a relação entre a MHR e a presença de PM. Métodos: Examinamos concecutivamente pacientes encaminhados para angiografia coronariana entre janeiro de 2013 e dezembro de 2016, e um total de 160 pacientes, uma parcela dos quais com PM, e outra com artérias coronárias normais, foram incluídos no estudo. As características angiográficas, demográficas e clínicas dos pacientes foram revisadas a partir de registros médicos. Monócitos e colesteróis HDL foram medidos através de hemograma completo. A MHR foi calculada como a razão entre a contagem absoluta de monócitos e o valor do colesterol HDL. Os valores de MHR foram divididos em três tercis, da seguinte forma: tercil inferior (8,25 ± 1,61); tercil moderado (13,11 ± 1,46); e tercil superior (21,21 ± 4,30). Considerou-se significativo um valor de p < 0,05. Resultados: A MHR foi significativamente maior no grupo com PM, em comparação com grupo controle com artérias coronárias normais. Verificamos que a prevalência de PM (p=0,002) aumentou à medida que se elevavam os tercis de MHR. A razão monócitos-colesterol HDL com ponto de corte de 13,35 apresentou sensibilidade de 59% e especificidade de 65,0% (área ROC sob a curva: 0,687, IC95%: 0,606-0,769, p < 0,001) na predição acurada do diagnóstico de PM. Na análise multivariada, a MHR (p = 0,013) mostrou-se um preditor independente significativo da presença de PM, após ajustes para outros fatores de risco. Conclusão: O presente estudo revelou uma correlação significativa entre MHR e PM.

Assessment of the Relationship between Monocyte to High-Density Lipoprotein Ratio and Myocardial Bridge.

BACKGROUND: Assessing the monocyte to high-density lipoprotein ratio (MHR) is a new tool for predicting inflamation, which plays a major role in atherosclerosis. Myocardial bridge (MB) is thought to be a benign condition with development of atherosclerosis, particularly at the proximal segment of the brigde. OBJECTIVE: To evaluate the relationhip between MHR and the presence of MB. METHODS: We consecutively scanned patients referred for coronary angiography between January 2013- December 2016, and a total of 160 patients who had a MB and normal coronary artery were enrolled in the study. The patients' angiographic, demographic and clinic characteristics of the patients were reviewed from medical records. Monocytes and HDL-cholesterols were measured via complete blood count. MHR was calculated as the ratio of the absolute monocyte count to the HDL-cholesterol value. MHR values were divided into three tertiles as follows: lower (8.25 ± 1.61), moderate (13.11 ± 1.46), and higher (21.21 ± 4.30) tertile. A p-value of < 0.05 was considered significant. RESULTS: MHR was significantly higher in the MB group compared to the control group with normal coronary arteries. We found the frequency of MB (p = 0.002) to increase as the MHR tertiles rose. The Monocyte-HDL ratio with a cut-point of 13.35 had 59% sensitivity and 65.0% specificity (ROC area under curve: 0.687, 95% CI: 0.606-0.769, p < 0.001) in accurately predicting a MB diagnosis. In the multivariate analysis, MHR (p = 0.013) was found to be a significant independent predictor of the presence of MB, after adjusting for other risk factors. CONCLUSION: The present study revealed a significant correlation between MHR and MB.

Different Accumulation of Elements in Proximal and Distal Parts of the Left Anterior Descending Artery Beneath the Myocardial Bridge.

To elucidate the action of the myocardial bridge (MB) on the coronary artery, the authors first prepared the hearts with the MB located in the middle one third of the left anterior descending (LAD) artery and then investigated element accumulation in the LAD artery of the hearts with the MB by direct chemical analysis. Eighty-four formalin-fixed adult Thai hearts were dissected and the MBs were found in 39 of 84 hearts with a total of 44 MBs. The 37 MBs were located in the middle one third of the LAD artery. To examine the action of the MB on element accumulation in the LAD artery, the hearts with the MB which was located in the middle one third of the LAD artery and was longer than 1.5 cm were used as Materials. The left main coronary (LMC) and LAD arteries were removed from these hearts successively and the isolated arteries were divided into eight to ten segments. After incineration of arteries with nitric acid and perchloric acid, seven element contents of Ca, P, S, Mg, Zn, Fe, and Na were determined by inductively coupled plasma-atomic emission spectrometry. To examine the endothelial changes of the LAD artery, the inner surface of segments of the LAD artery was observed by scanning electron microscopy. It was found that the extent of accumulation of Ca, P, Zn, and Na was not uniform throughout the LAD artery and was higher in the proximal part than in the distal part with regard to the LAD artery beneath the MB (the tunneled LAD artery). The extent of accumulation of Ca, P, Zn, and Na in the proximal part of the tunneled LAD artery was similar to that in the segments proximal to the MB, whereas the extent of accumulation of Ca, P, Zn, and Na in the distal part of the tunneled LAD artery was similar to that in the segments distal to the MB.

Hypercholesterolemia is Accounted for Atherosclerosis at the Proximal Arterial Segments of Myocardial Bridging: A Pilot Study.

Arterial shear stress was generally implicated in the development of atherosclerotic plaque (AP). Atherosclerotic plaque may be associated with myocardial bridging (MB). We evaluated the metabolic abnormalities which could determine the localization of AP at the proximal coronary segment of MB. We analyzed the patients with MB, AP&MB, and AP on left anterior descending (LAD) artery who were diagnosed by multislice computed tomography coronary angiography. Serum levels of metabolic parameters were compared among study groups. Patients with MB&AP and AP were significantly older than those in the MB group. Patients with MB&AP had AP and MB at the proximal and middle segments of LAD artery, respectively. Total cholesterol, low-density lipoprotein (LDL) cholesterol and very LDL, and triglyceride levels were significantly higher in patients with MB&AP and AP compared to only MB. Low-density lipoprotein cholesterol was significantly correlated with the type of coronary artery disease in multiple regression analysis. Myocardial bridging may be an anatomical determinant for the localization of AP proximal to itself in the presence of hypercholesterolemia.

Increase in mean platelet volume in patients with myocardial bridge.

AIM: Myocardial bridge is associated with atherosclerosis altered in shear stress and endothelial dysfunction. Mean platelet volume (MPV), a determinant of platelet activation, is shown to be related with atherosclerosis and endothelial dysfunction. In this study, we aimed to evaluate platelet function assessed by MPV in patients with myocardial bridge. METHODS: Forty-two patients with myocardial bridge in the left anterior descending artery (LAD) and 43 age- and gender-matched healthy participants were included in the study. Myocardial bridging was defined as an intramyocardial systolic compression or milking of a segment of an epicardial coronary artery on angiography. For the entire study population, MPV was measured using an automatic blood counter. RESULTS: The study population consisted of 42 patients with myocardial bridge (52.7 ± 10.2, 76.2% male) and 43 age- and sex-matched healthy control participants (52.1 ± 10.4, 74.4% male). Compared to the control group, MPV value was significantly higher in patients with myocardial bridge (8.9 ± 1.24 vs 8.3 ± 0.78; P = .01). Further, there were no significant differences between groups regarding hemoglobin level, platelet count, fasting blood glucose, and creatinine levels. CONCLUSIONS: Our study findings indicated that myocardial bridge is associated with elevated MPV values. Our results might partly explain the increased cardiovascular events in patients with myocardial bridge.

[Should the patient with myocardial bridge be advised not to performe extreme sport effort? Case of a patient with troponin I elevation after exercise]. / Przypadek chorego z odwyzszonym stezeniem troponiny I po wysilku.

Elevated levels of cardiac troponins are an established method of diagnosis of heart muscle necrosis. A case of a long distance amateur-marathon runner, who showed significant elevation of plasma troponin I after extreme physical effort is reported. The diagnostic examinations did not reveal atherosclerosis burden, but myocardial bridging of coronary artery. The authors describe the significance of the pathology in the view of extreme sport effort performed by the described patient.

Characteristics of stress tests and symptoms in patients with myocardial bridge and coronary artery spasm.

BACKGROUND: A relationship between coronary artery spasm (CAS) and myocardial bridge (MB) has been noticed. This study was designed to investigate the differences of stress tests and symptoms between CAS patients with or without MB. METHODS: Two hundred and sixteen patients with atypical chest pain who underwent coronary angiography and acetylcholine provocation test were divided into MB group (n=68) and nonmyocardial bridge group (NMB, n=148). The results of acetylcholine test, treadmill exercise electrocardiography, myocardial scintigraphy, and levels of plasma endothelin-1 and nitric oxide were compared between the two groups. RESULTS: Among these atypical chest pain patients, CAS was induced by acetylcholine in 85% MB patients and 53% NMB patients (P<0.001). A positive exercise electrocardiogram was identified in 71% MB patients and 8% NMB patients (P<0.001). Myocardial scintigraphy revealed ischemic changes in 67% MB patients and 9% NMB patients (P<0.001) and reverse redistribution in 87 and 69% (P<0.01), respectively. MB patients experienced exertional chest pain as well as at rest more frequently than NMB patients. Endothelin-1 levels were elevated in MB group complicated with CAS (P<0.01), whereas nitric oxide levels were reduced in the same cohort (P<0.05) compared with NMB group. CONCLUSION: MB might predispose to CAS in which endothelial dysfunction may play a part. CAS patients with MB usually present mixed chest pain and positive stress tests as well as reversal redistribution on myocardial scintigraphy whereas CAS patients without MB displayed chest pain at rest, negative stress test and reversal redistribution.