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THE EFFECT OF CORONARY ATHEROSCLEROSIS ON MYOCARDIAL BLOOD FLOW IN PATIENTS WITH CHEST PAIN AND UNOBSTRUCTED CORONARY ARTERIES
A1244 JACC April 1, 2014 Volume 63, Issue 12
Non Invasive Imaging The Effect of Coronary Atherosclerosis on Myocardial Blood Flow in Patients with Chest Pain and Unobstructed Coronary Arteries Poster Contributions Hall C Monday, March 31, 2014, 9:45 a.m.-10:30 a.m.
Session Title: Non Invasive Imaging: Stress and Contrast Echocardiography Abstract Category: 15. Non Invasive Imaging: Echo Presentation Number: 1248-46 Authors: Karen Nel, Roxy Senior, Christopher Boos, Joe Begley, Russell Bull, Delva Shamley, Ahmed Khattab, Kim Greaves, Bournemouth University, Bournemouth, United Kingdom, Poole Hospital NHS Foundation Trust, Poole, United Kingdom Background: Chest pain in the context of unobstructed coronary arteries (CA) is a common problem associated with increased adverse cardiovascular events. Studies have suggested microvascular dysfunction to be a cause which may reflect underlying atherosclerotic CA disease. We investigated in patients presenting with chest pain and unobstructed CA: 1) the prevalence of abnormal myocardial blood flow reserve (MBFR); 2) the relationship between myocardial blood flow (MBF) and plaque burden; 3) whether a low MBFR was associated with a particular chest pain characteristic. Methods: Patients with chest pain and unobstructed CA (<50% stenosis) on computed tomography angiography had MBF assessed using dipyridamole myocardial contrast echocardiography. Total plaque length (PL) in all three major CA was measured and compared to other risk factors. An extensive chest pain questionnaire was completed by each patient. Results: 183 patients (mean age 60±9.6 years, 53% male) were recruited. MBFR was low (<2) in 39% and <1.5 in 6% of patients. 62% of patients had plaque. Mean PL was 25.2mm (0-132), and mean calcium score 115 Agatston units (0-3132). PL showed a significant negative association with MBF stress (MBFs) (r = -0.36*) and MBFR (r = -0.37*). Multivariate analysis including risk factors indicated that male sex, body mass index, age, diabetes and smoking were negatively associated with MBFs. When including PL - only PL, male gender and body mass index remained predictors and PL was the strongest. Age, high-sensitivity C-reactive protein and PL were independently negatively associated with MBFR of which PL was the strongest predictor. PL also had a higher association with MBFs (β = -0.28*) and MBFR (β = -0.36*) than calcium score (β = 0.22** and β = 0.34*, respectively). There were no significant associations between MBF and chest pain characteristic. *p<0.001,**p<0.01. Conclusion: Almost 40% of patients with chest pain and unobstructed CA have a low MBFR. The extent of atherosclerosis as determined by PL is a highly significant independent predictor of MBFs and MBFR and has the strongest association when compared to other risk factors. A low MBFR does not appear to be associated with any chest pain characteristic.
Non Invasive Imaging The Effect of Coronary Atherosclerosis on Myocardial Blood Flow in Patients with Chest Pain and Unobstructed Coronary Arteries Poster Contributions Hall C Monday, March 31, 2014, 9:45 a.m.-10:30 a.m.
Session Title: Non Invasive Imaging: Stress and Contrast Echocardiography Abstract Category: 15. Non Invasive Imaging: Echo Presentation Number: 1248-46 Authors: Karen Nel, Roxy Senior, Christopher Boos, Joe Begley, Russell Bull, Delva Shamley, Ahmed Khattab, Kim Greaves, Bournemouth University, Bournemouth, United Kingdom, Poole Hospital NHS Foundation Trust, Poole, United Kingdom Background: Chest pain in the context of unobstructed coronary arteries (CA) is a common problem associated with increased adverse cardiovascular events. Studies have suggested microvascular dysfunction to be a cause which may reflect underlying atherosclerotic CA disease. We investigated in patients presenting with chest pain and unobstructed CA: 1) the prevalence of abnormal myocardial blood flow reserve (MBFR); 2) the relationship between myocardial blood flow (MBF) and plaque burden; 3) whether a low MBFR was associated with a particular chest pain characteristic. Methods: Patients with chest pain and unobstructed CA (<50% stenosis) on computed tomography angiography had MBF assessed using dipyridamole myocardial contrast echocardiography. Total plaque length (PL) in all three major CA was measured and compared to other risk factors. An extensive chest pain questionnaire was completed by each patient. Results: 183 patients (mean age 60±9.6 years, 53% male) were recruited. MBFR was low (<2) in 39% and <1.5 in 6% of patients. 62% of patients had plaque. Mean PL was 25.2mm (0-132), and mean calcium score 115 Agatston units (0-3132). PL showed a significant negative association with MBF stress (MBFs) (r = -0.36*) and MBFR (r = -0.37*). Multivariate analysis including risk factors indicated that male sex, body mass index, age, diabetes and smoking were negatively associated with MBFs. When including PL - only PL, male gender and body mass index remained predictors and PL was the strongest. Age, high-sensitivity C-reactive protein and PL were independently negatively associated with MBFR of which PL was the strongest predictor. PL also had a higher association with MBFs (β = -0.28*) and MBFR (β = -0.36*) than calcium score (β = 0.22** and β = 0.34*, respectively). There were no significant associations between MBF and chest pain characteristic. *p<0.001,**p<0.01. Conclusion: Almost 40% of patients with chest pain and unobstructed CA have a low MBFR. The extent of atherosclerosis as determined by PL is a highly significant independent predictor of MBFs and MBFR and has the strongest association when compared to other risk factors. A low MBFR does not appear to be associated with any chest pain characteristic.