Our study showed that age and NYHA class were important Enzalutamide in vivo predictors of LVEF response compared with other predictors such as BB dose. These results are consistent with prior studies that have shown that age and NYHA class have a strong association with LVEF response to BBs [14, 22]. Regarding dosing of BBs, in the multicenter oral carvedilol heart failure assessment (MOCHA) trial, carvedilol (12.5–50 mg/day)

generated dose-related LVEF improvement (5–8 %) in HF patients, of whom 77 % were Caucasians [7]. The carvedilol dose in our patients was about the same Fludarabine dose as that used in the MOCHA trial, but the magnitude of the LVEF improvement for Caucasians in our study was higher. Although this finding is consistent with other studies [10, 42, 43], to the best of our knowledge there are no prior studies regarding BB dosing and LVEF response in Hispanics. In our study, we also confirmed the finding that the effect of BBs on

LVEF response was similar irrespective of type of BB used (metoprolol or carvedilol) [10, 42, 43]. Therefore, Hispanics with NICM may have worse post-response LVEF decline irrespective of BB dose and type of BB used compared with other races. Given that prior data have shown differences in LVEF response to BBs [15, 29–32, 40, 41] due to genetic differences (B-gene polymorphisms), genetic background might explain variation in post-response LVEF decline [15].

Finally, baseline LVEF was an important predictor Everolimus nmr of post-response LVEF decline. Our data is consistent with prior studies that have shown that baseline LVEF has a significant association with response to BB therapy [9, 10]. The not increase in LVEF is greater in patients with lower baseline LVEF after treatment with BB therapy [9]. The down-regulation of beta-1-receptor density may be greater with higher chronic catecholamine exposure, which may be the case with more severe cardiomyopathy [10]. BB therapy may then up-regulate beta-1-receptor density to a greater extent in these more severe disease states. Due to the retrospective nature of the study, expected limitations were encountered. The number of patients enrolled in this study precluded restriction of analyses to only those with low ejection fraction or only those with symptoms of HF. Those variables that were determined by self-report or review of the medical records are beyond the control of the investigators and, thus, subject to error. There was also a lack of availability of data on medical therapy and a lack of information regarding socioeconomic status, including education and income, that may have had an effect on HF outcomes. In addition, this is a single-center study and the findings may not confer external validity.