Patients with rheumatoid arthritis have an increased risk for cardiovascular disease. Because of accelerated atherosclerosis and changes in left ventricular (LV) geometry, circumferential and longitudinal (C&L) LV systolic dysfunction (LVSD) may be impaired in these patients despite preserved LV ejection fraction. The aim of this study was to determine the prevalence of and factors associated with combined C&L LVSD in patients with rheumatoid arthritis.
One hundred ninety-eight outpatients with rheumatoid arthritis without overt cardiac disease were prospectively analyzed from January through June 2014 and compared with 198 matched control subjects. C&L systolic function was evaluated by stress-corrected midwall shortening (sc-MS) and tissue Doppler mitral annular peak systolic velocity (S'). Combined C&L LVSD was defined if sc-MS was <86.5% and S' was <9.0 cm/sec (the 10th percentiles of sc-MS and S' derived in 132 healthy subjects).
Combined C&L LVSD was detected in 56 patients (28%) and was associated with LV mass (odds ratio, 1.03; 95% CI, 1.01-1.06; P = .04) and concentric LV geometry (odds ratio, 2.76; 95% CI, 1.07-7.15; P = .03). By multiple logistic regression analysis, rheumatoid arthritis emerged as an independent predictor of combined C&L LVSD (odds ratio, 2.57; 95% CI, 1.06-6.25). The relationship between sc-MS and S' was statistically significant in the subgroup of 142 patients without combined C&L LVSD (r = 0.40, F < 0.001), having the best fitting by a linear function (sc-MS = 58.1 + 3.34 × peak S'; r(2) = 0.19, P < .0001), absent in patients with combined C&L LVSD.
The aim of this "notice of clarification" is to analyze in brief the similarities and to underline the differences between the current article (defined as "paper J") and a separate article entitled "Prevalence and Factors Associated with Subclinical Left Ventricular Systolic Dysfunction Evaluated by Mid-Wall Mechanics in Rheumatoid Arthritis" (defined as "paper E"), which was written several months before paper J, and recently accepted for publication by the journal "Echocardiography" (Cioffi et al. http://dx.doi.org/10.1111/echo.13186). We wish to explain more clearly how the manuscript described in "paper J" relates to the "paper E" and the context in which it ought to be considered. Data in both papers were derived from the same prospective database, so that it would appear questionable if the number of the enrolled patients and/or their clinical/laboratory/echocardiographic characteristics were different. Accordingly, both papers reported that 198 patients with rheumatoid arthritis (RA) were considered and their characteristics were identical, due to the fact that they were the same subjects (this circumstance is common and mandatory among all studies in which the patients were recruited from the same database). These are the similarities between the papers. In paper E, which was written several months before paper J, we focused on the prevalence and factors associated with impaired circumferential left ventricular (LV) systolic function measured as mid-wall shortening (corrected for circumferential end-systolic stress). We found that 110 patients (56% of the whole population) demonstrated this feature. Thus, these 110 patients were the object of the study described in paper E, in which we specifically analyzed the factors associated with the impairment of stress-corrected mid-wall shortening (sc-MS). The conclusions of that paper were: (i) subclinical LV systolic dysfunction (LVSD) is detectable in more than half RA population without overt cardiac disease as measured by sc-MS, (ii) RA per se is associated with LVSD, and (iii) in RA patients only LV relative wall thickness was associated with impaired sc-MS based upon multivariate logistic regression analysis. Differently, in the paper J, we focused on the prevalence and factors associated with combined impairment of circumferential and longitudinal shortening (C&L) in 198 asymptomatic patients with RA. We found that 56 patients (28% of the whole population) presented this feature. Thus, these 56 patients were analyzed in detail in this study, as well as the factors associated with the combined impairment of C&L shortening. In paper J, we evaluated sc-MS as an indicator of circumferential systolic LV shortening, and we also determined the average of tissue Doppler measures of maximal systolic mitral annular velocity at four different sampling sites ( S') as an indicator of longitudinal LV systolic shortening. This approach clearly demonstrates that in paper J, we analyzed data deriving from the tissue Doppler analysis, which were not taken into any consideration in paper E. The investigation described in paper J made evident several original and clinically relevant findings. In patients with RA: (i) the condition of combined C&L left ventricular systolic dysfunction (LVSD) is frequent; (ii) these patients have comparable clinical and laboratory characteristics with those without combined C&L LVSD, but exhibit remarkable concentric LV geometry and increased LV mass, a phenotype that can be consider a model of compensated asymptomatic chronic heart failure; (iii) RA is an independent factor associated with combined C&L LVSD; (iv) no relationship between indexes of circumferential and longitudinal function exists in patients with combined C&L LVSD, while it is statistically significant and positive when the subgroup of patients without combined C&L LVSD is considered, having the best fitting by a linear function. All these findings are unique to the paper J and are not presented (they could not have been) in paper E. It appears clear that, starting from the same 198 patients included in the database, different sub-groups of patients were selected and analyzed in the two papers (they had different echocardiographic characteristics) and, consequently, different factors emerged by the statistical analyses as covariates associated with the different phenotypes of LVSD considered. Importantly, both papers E and J had a very long gestation because all reviewers for the different journals found several and important issues that merited to be addressed: a lot of changes were proposed and much additional information was required, particularly by the reviewers of paper E. Considering this context, it emerges that although paper E was written well before paper J, the two manuscripts were accepted at the same time (we received the letters of acceptance within a couple of weeks). Thus, the uncertainty about the fate of both manuscripts made it very difficult (if not impossible) to cite either of them in the other one and, afterward, we just did not think about this point anymore. Of note, the idea to combine in the analysis longitudinal function came therefore well after the starting process of revision of the paper E and was, in some way inspired by a reviewer's comment. That is why we did not put both findings in the same paper. We think that our explanations provide the broad audience of your journal a perspective of transparency and our respect for the readers' right to understand how the work described in the paper J relates to other work by our research group. Giovanni Cioffi On behalf of all co-authors Ombretta Viapiana, Federica Ognibeni, Andrea Dalbeni, Davide Gatti, Carmine Mazzone, Giorgio Faganello, Andrea Di Lenarda, Silvano Adami, and Maurizio Rossini.
Combined C&L LVSD is detectable in about one fourth of patients with asymptomatic rheumatoid arthritis and is associated with LV concentric remodeling and hypertrophy. Rheumatoid arthritis predicts this worrisome condition, which may explain the increased risk for cardiovascular events in these patients.