Rheumatol Int DOI 10.1007/s00296-015-3220-6
Rheumatology INTERNATIONAL
LETTER TO THE EDITOR - FOOD FOR THOUGHT
Diastolic dysfunction and endothelial dysfunction in systemic lupus erythematosus Ali Yildiz · Serdar Soydinc
Received: 14 December 2014 / Accepted: 13 January 2015 © Springer-Verlag Berlin Heidelberg 2015
With great interest we have read the recent article of Chin et al. [1] on the association of endothelial function and myocardial diastolic function in women with systemic lupus erythematosus (SLE) and normal radionuclide myocardial perfusion imaging (MPI). In their study, authors revealed normal diastolic function (E/e′ ≤ 8) and definite diastolic dysfunction with E/e′ > 13, respectively, in 61 and 5 % of patients. Authors reported that the brachial artery flow-mediated vasodilatation (FMD%) was associated with E/e′ independent of confounding factors as well. In our opinion, some points of this work are not sufficiently clear. First of all, authors have stated in the “study participants” section that the women with “coronary artery disease, either previous myocardial infarction or cardiac investigations demonstrating myocardial ischemia, infarction or a > 50 % luminal stenosis in a major epicardial vessel” were excluded and study participants underwent pharmacological stress radionuclide MPI to exclude myocardial ischemia. Based on the exclusion criteria and negative radionuclide MPI testing, authors defined the study population as “patients with SLE and no coronary artery disease” at the end of the introduction (last two lines of the first page). However, negative radionuclide MPI does not exclude coronary artery disease. Additionally, negative radionuclide MPI might not exclude significant coronary artery disease due to the well-known limitation of radionuclide MPI: “balanced ischemia” [2]. Therefore, considerable
This comment refers to the article available at doi:10.1007/s00296-014-2968-4. A. Yildiz (*) · S. Soydinc Department of Cardiology, School of Medicine, Hacettepe University, 06100 Ankara, Turkey e-mail: [email protected]
amount of cases with normal radionuclide MPI and coronary artery disease might have been included in the present study. Coronary artery disease might lead to both endothelial dysfunction and myocardial diastolic dysfunction [3, 4]. Therefore, impaired FMD and/or myocardial diastolic dysfunction in SLE in the present study might partly be due to coronary artery disease. As a second comment, authors stated in the discussion section that the “left ventricular mass index was not associated with diastolic function despite an association with systolic blood pressure” and “systolic blood pressure may have influenced myocardial diastolic function via other mechanisms, such as microvascular ischemia and aortic stiffness” rather than hypertensive cardiomyopathy. In the present study, nearly 39 % (n = 15) of cases have diastolic dysfunction, whereas 23.7 % (n = 9) of cases were hypertensive without known number of cases with hypertensive cardiomyopathy. In our opinion concluding that the “systolic blood pressure may have influenced myocardial diastolic function via other mechanisms, such as microvascular ischemia and aortic stiffness” rather than hypertensive cardiomyopathy might be cumbersome based on the data of 15 cases with diastolic dysfunction, nine cases with hypertension and unknown number of cases with hypertensive cardiomyopathy, since this study was neither aimed to nor has the power to discriminate the mechanism of diastolic dysfunction with regard to hypertension. Antihypertensive medications (none were noted for nine hypertensive cases) might also influence the association of hypertension with both endothelial dysfunction and diastolic dysfunction [5, 6]. As a last but not least important comment, in Table 3 authors have reported that systolic blood pressure was associated with diastolic function E/e′ on univariate and multivariate linear regression analyses, respectively, with
13
regression coefficient [and 95 % confidence interval (CI)] values of 0.90 (0.30–1.40) and 0.66 (0.13–1.19) with p values of
Rheumatology INTERNATIONAL
LETTER TO THE EDITOR - FOOD FOR THOUGHT
Diastolic dysfunction and endothelial dysfunction in systemic lupus erythematosus Ali Yildiz · Serdar Soydinc
Received: 14 December 2014 / Accepted: 13 January 2015 © Springer-Verlag Berlin Heidelberg 2015
With great interest we have read the recent article of Chin et al. [1] on the association of endothelial function and myocardial diastolic function in women with systemic lupus erythematosus (SLE) and normal radionuclide myocardial perfusion imaging (MPI). In their study, authors revealed normal diastolic function (E/e′ ≤ 8) and definite diastolic dysfunction with E/e′ > 13, respectively, in 61 and 5 % of patients. Authors reported that the brachial artery flow-mediated vasodilatation (FMD%) was associated with E/e′ independent of confounding factors as well. In our opinion, some points of this work are not sufficiently clear. First of all, authors have stated in the “study participants” section that the women with “coronary artery disease, either previous myocardial infarction or cardiac investigations demonstrating myocardial ischemia, infarction or a > 50 % luminal stenosis in a major epicardial vessel” were excluded and study participants underwent pharmacological stress radionuclide MPI to exclude myocardial ischemia. Based on the exclusion criteria and negative radionuclide MPI testing, authors defined the study population as “patients with SLE and no coronary artery disease” at the end of the introduction (last two lines of the first page). However, negative radionuclide MPI does not exclude coronary artery disease. Additionally, negative radionuclide MPI might not exclude significant coronary artery disease due to the well-known limitation of radionuclide MPI: “balanced ischemia” [2]. Therefore, considerable
This comment refers to the article available at doi:10.1007/s00296-014-2968-4. A. Yildiz (*) · S. Soydinc Department of Cardiology, School of Medicine, Hacettepe University, 06100 Ankara, Turkey e-mail: [email protected]
amount of cases with normal radionuclide MPI and coronary artery disease might have been included in the present study. Coronary artery disease might lead to both endothelial dysfunction and myocardial diastolic dysfunction [3, 4]. Therefore, impaired FMD and/or myocardial diastolic dysfunction in SLE in the present study might partly be due to coronary artery disease. As a second comment, authors stated in the discussion section that the “left ventricular mass index was not associated with diastolic function despite an association with systolic blood pressure” and “systolic blood pressure may have influenced myocardial diastolic function via other mechanisms, such as microvascular ischemia and aortic stiffness” rather than hypertensive cardiomyopathy. In the present study, nearly 39 % (n = 15) of cases have diastolic dysfunction, whereas 23.7 % (n = 9) of cases were hypertensive without known number of cases with hypertensive cardiomyopathy. In our opinion concluding that the “systolic blood pressure may have influenced myocardial diastolic function via other mechanisms, such as microvascular ischemia and aortic stiffness” rather than hypertensive cardiomyopathy might be cumbersome based on the data of 15 cases with diastolic dysfunction, nine cases with hypertension and unknown number of cases with hypertensive cardiomyopathy, since this study was neither aimed to nor has the power to discriminate the mechanism of diastolic dysfunction with regard to hypertension. Antihypertensive medications (none were noted for nine hypertensive cases) might also influence the association of hypertension with both endothelial dysfunction and diastolic dysfunction [5, 6]. As a last but not least important comment, in Table 3 authors have reported that systolic blood pressure was associated with diastolic function E/e′ on univariate and multivariate linear regression analyses, respectively, with
13
regression coefficient [and 95 % confidence interval (CI)] values of 0.90 (0.30–1.40) and 0.66 (0.13–1.19) with p values of
